Basal cell carcinoma

(medicine) A locally invasive, rarely metastatic nevoid tumor of the epidermis. Also known as basal-cell epithelioma.

Key Terms: Albinism, Biopsy, Dermis, Epidermis, Fluorouracil, Hair follicles, Imiquimod, Interferon alpha, Local anesthetic, Lymph node, Nonsteroidal anti-inflammatory drugs, Oncologist, Pathologist, Premalignant skin lesion, Selenium, Squamous cell carcinoma, Sweat glands, TNM system.

Definition

A basal cell carcinoma is a skin cancer that originates from basal keratinocytes in the top layer of the skin, the epidermis. Sometimes these tumors are called "rodent ulcers."

Description

Basal keratinocytes are unpigmented skin cells found deep in the epidermis, hair follicles, and sweat glands. When they become cancerous, these cells invade the dermis (the layer of skin just below the epidermis) and spread out into the normal skin. They become visible as a small growth or area of change in the skin's appearance. These tumors can appear anywhere on the body, but most become evident on the face and neck.

Most basal cell carcinomas are small tumors that can be cured with simple surgeries. They usually grow quite slowly. However, neglected or aggressive tumors can invade vast amounts of skin. These cancers can also spread along bones, cartilage, muscles, and, more rarely, nerves. Some tumors may eventually reach the eye or brain or become large enough to significantly disfigure the face. These serious consequences are more likely if the tumor lies close to bone and cartilage—for instance, at the corner of the eye. Very few basal cell carcinomas spread to more distant organs; no more than five out of every 10,000 of these tumors metastasize. Most that do are very large, deep cancers that have been visible for years.

Demographics

Basal cell carcinomas are most common from middle age until old age. They are more frequent in men than women. These cancers seem to be associated with exposure to ultraviolet light; they tend to develop on sun-exposed areas and are more common in people living near the equator. Those who have lighter skin are more susceptible; fair-haired blonds are more likely to develop tumors than people with darker complexions. In the United States, Caucasians have a 28% to 33% chance of developing a basal cell carcinoma over a lifetime.

Weakened immunity may also play a role. Those who have had an organ transplanted or who have contracted acquired immune deficiency syndrome (AIDS) are more likely to develop one of these cancers.

Basal cell carcinomas are particularly common among individuals with a rare genetic disease called nevoid basal cell carcinoma syndrome (Gorlin's syndrome). Individuals with this disease can be born with basal cell carcinomas or begin to develop them in childhood. Some have few or no cancers; others have more than 250. These tumors seldom grow much before puberty, but during and after adolescence they can spread rapidly. Other symptoms include small pits in the palms and soles, cysts in the jaw, and other abnormalities in the bones.

Causes and Symptoms

Basal cell carcinomas are caused by genetic damage to a skin cell. Exposure to ultraviolet light and x rays, suppression of the immune system, and genetic factors seem to increase the risk that this will happen. The exact cause, however, is rarely known.

Several types of basal cell carcinomas exist. Nodular basal cell carcinomas are the most common form. These tumors begin as a tiny red or clear bump on the skin. Over time, they develop into a growth with clear or white "pearly" raised edges and, often, a depressed area in the middle. A network of tiny blood vessels usually crisscrosses the surface, and the tumor may bleed repeatedly or crust over. Morpheaform (sclerosing, morpheic) basal cell carcinomas are more difficult to detect. These tumors are usually pale, firm, flat growths that can blend into the normal skin around them. Many look just like a scar. Superficial basal cell carcinomas are flat, red, scaly plaques that can look like psoriasis or eczema. Unlike other basal cell carcinomas, they are usually found on the arms, legs, and torso. Pigmented basal cell carcinomas are brown, black, or blue; they are usually of the nodular type and can look like a melanoma.

Some general characteristics of skin cancers include:

• irregular or ragged borders
• non-symmetrical shape
• a change in color
• a size greater than 0.2 inches (6 mm)

Diagnosis

Basal cell carcinomas are usually diagnosed with a skin biopsy taken in the doctor's office. This is generally a brief and simple procedure. After numbing the skin with an injection of local anesthetic, the doctor snips out a tiny piece of the tumor. The skin sample must be sent to a trained pathologist to be analyzed. It may take up to a week for the biopsy results to come back. Sometimes the tumor is removed immediately after the biopsy, before the results are known.

Treatment Team

Primary care physicians remove some basal cell carcinomas; other cancers, including larger or more complicated tumors, may be referred to a dermatologist. The services of a plastic surgeon are occasionally necessary. In the rare event that a tumor metastasizes, an oncologist and full cancer treatment team become involved.

Clinical Staging, Treatments, and Prognosis

Basal cell carcinomas rarely spread into the lymph nodes and internal organs. For this reason, doctors tend not to stage them. If staging is needed, the TNM (tumor, lymph node, and metastases) system is usually used. For basal cell carcinomas, this can be simplified into the following five categories:

• Stage 0: The cancer is very small and has not yet spread from the epidermis to the dermis.
• Stage 1: The cancer is less than 2 cm (0.8 inches) in diameter. No cancer cells can be found in lymph nodes or other internal organs.
• Stage 2: The cancer is more than 2 cm (0.8 inches) in diameter. No cancer cells can be found in lymph nodes or other internal organs.
• Stage 3: Cancer cells have been found either in nearby lymph nodes or in the bone, muscle, or cartilage beneath the skin (or in both locations).
• Stage 4: Cancer cells have been discovered in internal organs, most often the lungs or lymph nodes, that are distant from the skin. A stage four cancer can be any size.

Treatment Options for Non-Metastatic, Non-Staged Tumors

For most non-metastatic, non-staged cancers, there may be several treatment options. The recommended treatment depends on the size and type of tumor, its location, and cosmetic considerations. The cure rates for most of the following techniques are approximately 85% to 95%, but vary with tumor size and other factors. Moh's micrographic surgery has a five-year cure rate of 96%. Success rates for recurrent tumors are approximately 50% with most techniques and 90% with Moh's surgery.

In conventional surgery, the doctor numbs the area with an injection of local anesthetic, then cuts out the tumor and a small margin of normal skin around it. The wound is closed with a few stitches. One advantage to conventional surgery is that the wound usually heals quickly. Another benefit is that the complete cancer can be sent to a pathologist for evaluation. If the skin around the tumor is not completely free of cancer cells, the tumor can be treated again immediately.

Moh's micrographic surgery is a variation of conventional surgery. In this procedure, the surgeon examines each piece of skin under the microscope as it is removed. If any cancer cells remain, another slice is taken from that area and checked. These steps are repeated until the edges of the wound are clear of tumor cells, then the wound is closed. The advantage to this technique is that all of the visible cancer cells are removed but as much normal skin as possible is spared. Moh's surgery is often used for larger or higher risk tumors and when cosmetic considerations are important. The main disadvantage is that it takes much longer than conventional surgery and requires a specially trained surgeon.

A laser is sometimes used as a cutting instrument instead of a scalpel. Laser light can also destroy some cancer cells directly. A disadvantage to laser surgery is that the wounds from some lasers heal more slowly than cuts from a scalpel. The advantage is that bleeding is minimal.

In electrodessication and curettage, the physician scoops out the cancer cells with a spoon-shaped instrument called a curette. After most of the tumor is gone, the remaining cancerous tissue is destroyed with heat from an electrical current. The wound is left open to heal like an abrasion. It leaks fluid, crusts over, and heals during the next two to six weeks. This is a safe and easy method for removing many basal cell carcinomas. One disadvantage is that there is no skin sample to confirm that the tumor is completely gone. The electrical current used during this surgery can interfere with some pace-makers and larger tumors may heal with a noticeable scar.

In cryosurgery, liquid nitrogen is used to freeze the tumor and destroy it. This treatment is another type of blind destruction; there is no skin sample to make sure the cancer cells have all been killed. Patients report swelling and pain after cryosurgery, and a wound appears a few days later where the cells were destroyed. When the site heals, it has usually lost its normal pigment. There is a risk of nerve damage with this technique.

Radiation therapy is an uncommon treatment for basal cell carcinoma. One disadvantage is the inconvenience: multiple treatments, over a period of weeks, are necessary. Tumors that return after radiation also tend to grow more quickly than the original cancer. In addition, x rays may promote new skin cancers. Radiation therapy may be an option for patients who cannot undergo even minor surgery. It is also used occasionally as an adjunct to surgery. One advantage is that the cosmetic results can be very good.

Occasionally a lotion containing fluorouracil is applied to the tumor. This drug cannot penetrate very far and cancer cells in the deeper parts of the tumor may not be destroyed. The main advantage to this treatment is its simplicity.

Treatment Options for Metastatic Cancers

Cancers that have spread to internal organs are treated with a combination of surgery, radiation, and chemotherapy.

Prognosis

The prognosis for small, uncomplicated basal cell carcinomas is very good. The vast majority of these tumors can be successfully removed. However, cancers that were not completely destroyed may regrow. If the edges of the removed skin contain cancer cells, the chance that the tumor will return within the next five years is about 40%. Regrowth is more likely with cancers larger than 0.8 inches (2 cm), those on the face (particularly around the nose, eye, and ear), and higher risk types such as morpheaform tumors. Tumors can redevelop in the scar from the surgery, on the edges of the surgery site, or deep in the skin. These cancers may not look like the original tumor. Patients should be particularly watch-ful for minor changes in the appearance of the scar or sores that appear nearby.

Cancers that metastasize spread most often to the lymph nodes and lungs. The prognosis for metastatic cancers is poor, even with treatment. Survival after spread of the cancer to internal organs is eight months on the average and seldom more than a year and a half.

Coping With Cancer Treatment

Most basal cell carcinomas are removed with techniques that cause few, if any, lasting side effects. Patients who have cosmetic concerns may wish to discuss them with their doctor.

Clinical Trials

In photodynamic laser therapy, a dye activated by laser light destroys the cancer. This dye is spread onto the skin, injected, or drunk. During a waiting period, normal cells clear the dye, then a laser activates the remainder. As of 2001, this technique was only useful for cancers very near the surface of the skin. One side effect after treatment is a period of excessive sun-sensitivity. Several clinical trials are in progress.

In 1999, researchers first reported that imiquimod 5% cream, spread onto the skin several times a week, could destroy small nodular or superficial basal cell carcinomas. The side effects from this treatment were mainly local skin reactions such as itching, rashes, and redness. In 2003, new studies continued to show its effectiveness and the drug company that marketed the cream filed new applications with the U.S. Food and Drug Administration (FDA) for treatment of superficial basal cell carcinoma.

Interferon alpha injected into the tumor is sometimes effective for basal cell carcinomas. This experimental treatment is mainly used for less dangerous forms such as the nodular type.

Retinoids, drugs related to vitamin A, may have some effect on basal cell carcinomas. These drugs are taken internally and can have significant serious side effects.

Prevention

The risk factors for basal cell carcinoma include:

• ethnic background
• complexion
• geographic location
• increasing age
• exposure to x rays and ultraviolet light (both UVA and UVB)
• a history of premalignant skin lesions or skin cancer
• genetic disorders such as nevoid basal cell carcinoma syndrome, xeroderma pigmentosum, and albinism
• suppression of the immune system by AIDS or an organ transplant

Some important preventive steps include wearing protective clothing and hats in the sun, using a sunscreen, avoiding the sun between 10 A.M. and 4 P.M., and staying away from suntanning booths. Checking the skin for early signs of cancer also is critical.

Drugs related to vitamin A (including beta-carotene, retinol, and isotretinoin), vitamin E, nonsteroidal anti-inflammatory drugs (NSAIDS), and selenium have been suggested as possibly preventing basal cell carcinoma. A 2003 study reported that selenium is not effective in preventing basal cell carcinoma and may even increase risk of squamous cell carcinoma.

Special Concerns

Because many basal cell carcinomas are found on the face and neck, cosmetic concerns are a priority for many patients. If there is a risk of noticeable scarring or damage, a patient may wish to ask about alternative types of removal or inquire about the services of a plastic surgeon.

Questions to Ask the Doctor

• What treatment(s) would you recommend for my tumor?
• How effective would you expect each of them to be, for a tumor of this size and in this location?
• How much cosmetic damage am I likely to see with each treatment?
• Are there any alternatives?
• How should I prepare for the procedure?
• What is the risk that my tumor in particular will regrow?

After treatment, it is important to return to the doctor periodically to check for regrowth or new skin cancers. Approximately 36% of all patients find a new basal cell or squamous cell carcinoma within the next five years. Having a basal cell carcinoma before the age of 60 may also increase the chance of developing other cancers in internal organs.

Resources

Books

Keefe, Kristin A., and Frank L. Meyskens, Jr. "Cancer Prevention." In Clinical Oncology, edited by M. Abeloff, J. Armitage, A. Lichter, and J. Niederhuber, 2nd ed. Philadelphia: Churchhill Livingstone, 2000.

Rohrer, Thomas E. "Cancer of the Skin." In Conn's Current Therapy; Latest Approved Methods of Treatment for the Practicing Physician, edited by R. Rakel, et al., 52nd ed. Philadelphia: W. B. Saunders, 2000.

Wolfe, Jonathan. "Nonmelanoma Skin Cancers: Basal Cell and Squamous Cell Carcinoma." In Clinical Oncology, edited by M. Abeloff, J. Armitage, A. Lichter, and J. Niederhuber, 2nd ed. Philadelphia: Churchhill Livingstone, 2000.

Periodicals

Beutner, Karl R., John K. Geisse, Donita Helman, Terry L. Fox, Angela Ginkel, and Mary L. Owens. "Therapeutic Response of Basal Cell Carcinoma to the Immune Response Modifier Imiquimod 5% Cream." Journal of the American Academy of Dermatology 41, no. 6 (December 1999): 1002-7.

Duffield-Lillico, Anna J., et al. "Selenium Supplementation and Secondary Prevention of Nonmelanoma Skin Cancer in A Randomized Trial." Journal of the National Cancer Institute 95 (October 1, 2003): 1477-1485.

Garner, Kyle L., and Wm. Macmillian Rodney. "Basal and Squamous Cell Carcinoma." Primary Care; Clinics in Office Practice 27, no. 2 (June 2000): 477-58.

"Is Sunscreen an Enabler?" Harvard Health Letter 25, no. 9 (July 2000): 1-3.

Jerant, Anthony F., Jennifer T. Johnson, Catherine Demastes Sheridan, and Timothy J. Caffrey. "Early Detection and Treatment of Skin Cancer." American Family Physician 62 (July 15, 2000): 357-68, 375-6, 381-2.

Zoler, Mitchell L. "Imiquimod Up for FDA Approval to Treat BCC, AK; Phase III Trial Results." Internal Medicine News 36 (October 1, 2003): 52.

Organizations

Nevoid Basal Cell Carcinoma Syndrome Support Network. 162 Clover Hill Street, Marlboro, MA 01752. (800) 815-4447. souldansur@aol.com.

Skin Cancer Foundation. 245 Fifth Ave., Suite 2402, New York, NY 10016. (212) 725-5176. .

Other

"Non-Melanoma Staging." Oncology Channel. Mar. 2001. [cited June 29, 2001]. .

"Nonmelanoma Skin Cancer Treatment—Health Professionals." CancerNet, National Cancer Institute. Aug. 2000. [cited June 25, 2001]. .

"Skin Cancer." CancerLinksUSA. 1999. [cited June 29, 2001]. .

—Anna Rovid Spickler, D.V.M., Ph.D.; Teresa G. Odle

An epithelial neoplasm with a basic structure resembling the basal cells of the epidermis. It develops from basal cells of the epidermis or from the outer cells of hair follicles or sebaceous glands, particularly the middle third of the face. It rarely, if ever, metastasizes but is locally invasive. It does not arise from oral mucosa.

A slow-growing, locally invasive, but rarely metastasizing neoplasm of the skin derived from basal cells of the epidermis or hair follicles. Also called basal cell epithelioma.

Basal cell carcinoma
Classification and external resources
ICD-9	173
ICD-O:	M8090/3-8093/3
OMIM	605462
MedlinePlus	000824
eMedicine	med/214
MeSH	D002280

Basal cell carcinoma is the most common type of skin cancer. It rarely metastasizes or kills, but it is still considered malignant because it can cause significant destruction and disfigurement^[1][2] by invading surrounding tissues. Statistically, approximately 3 out of 10 Caucasians develop a basal cell cancer within their lifetime.^[3] In 80 percent of all cases, basal cell cancers are found on the head and neck.^[3] There appears to be an increase in the incidence of basal cell cancer of the trunk in recent years.^[3]

Contents 1 Types 2 Distribution 3 Presentation 4 Diagnosis 5 Pathophysiology 6 Prevention and early diagnosis 7 Treatment 8 Prognosis 9 Epidemiology 10 Image gallery 11 References 12 External links

Types

Basal cell carcinomas may be divided into the following types:^{[4][5]:646-650}

• Nodular basal cell carcinoma (Classic basal cell carcinoma)
• Cystic basal cell carcinoma
• Cicatricial basal cell carcinoma (Morpheaform basal cell carcinoma, Morphoeic basal cell carcinoma)
• Infiltrative basal cell carcinoma
• Micronodular basal cell carcinoma
• Superficial basal cell carcinoma (Superficial multicentric basal cell carcinoma)
• Pigmented basal cell carcinoma
• Rodent ulcer (Jacobi ulcer)
• Fibroepithelioma of Pinkus
• Polypoid basal cell carcinoma
• Pore-like basal cell carcinoma
• Aberrant basal cell carcinoma

For simplicity, one can also divide basal cell carcinoma into 3 groups, based on location and difficulty of therapy:

1. Superficial basal cell carcinoma, or some might consider to be equivalent to "in-situ". Very responsive to topical chemotherapy such as Aldara, or Fluorouracil. It is the only type of basal cell cancer that can be effectively treated with topical chemotherapy.
2. Infiltrative basal cell carcinoma, which often encompasses morpheaform and micronodular basal cell cancer. More difficult to treat with conservative treatment methods such as electrodessiccation and currettage, or with currettage alone.
3. Nodular basal cell carcinoma, which essentially include most the remaining categories of basal cell cancer. It is not unusual to encounter morphologic features of several variants of basal cell cancer in the same tumor.

See also:

• Nevoid basal cell carcinoma syndrome

Distribution

About two-thirds of basal cell carcinomas occur on sun-exposed areas of the body. One-third occur on areas of the body that are not exposed to sunlight, emphasizing the genetic susceptibility of basal cell cancer patients.

Presentation

Patients present with a shiny, pearly nodule. However, superficial basal cell cancer can present as a red patch like eczema. Infiltrative or morpheaform basal cell cancers can present as a skin thickening or scar tissue - making diagnosis difficult without using tactile sensation and a skin biopsy. It is often difficult to distinguish basal cell cancer from acne scar, actinic elastosis, and recent cryodestruction inflammation.

Diagnosis

To diagnose basal cell carcinomas, a skin biopsy is taken for pathological study. The most common method is a shave biopsy under local anesthesia. Most nodular basal cell cancers can be diagnosed clinically, however, other variants can be very difficult to distinguish from benign lesions such as intradermal nevus, sebaceomas, fibrous papules, early acne scars, and hypertrophic scarring.^[6]

Pathophysiology

Histology of a nodular basal cell carcinoma

Basal cell carcinomas develop in the basal cell layer of the skin. Sun light exposure leads to the formation of thymine dimers, a form of DNA damage. While DNA repair removes most UV-induced damage, not all crosslinks are excised. There is, therefore, cumulative DNA damage leading to mutations. Apart from the mutagenesis, sunlight depresses the local immune system, possibly decreasing immune surveillance for new tumor cells.

Basal-cell carcinoma also develops as a result of basal-cell nevus syndrome, or Gorlin's syndrome, which is also characterized by odontogenic keratocysts of the jaw, palmar or plantar (sole of the foot) pits, calcification of the falx cerebri (in the center line of the brain) and rib abnormalities. The cause of the syndrome is a mutation in the PTCH1 tumor-suppressor gene at chromosome 9q22.3, which inhibits the hedgehog signaling pathway. A mutation in the SMO gene, which is also on the hedgehog pathway, also causes basal-cell carcinoma.^[7]

Prevention and early diagnosis

Basal cell carcinoma is the most common skin cancer. It occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers; therefore, doctors recommend sun screens. One-third occur in non-sun-exposed areas.

The use of a chemotherapeutic agent such as 5-Fluorouracil or Imiquimod, can prevent development of skin cancer. It is usually recommended to individuals with extensive sun damage, history of multiple skin cancers, or precancerous growths. It is often repeated every 2 to 3 years to further decrease the risk of skin cancer.

Treatment

The following methods are employed in the treatment of basal cell carcinoma (BCC):

• Standard surgical excision with either frozen section histology, or parafin embedded fixed tissue pathology. This is the preferred method for removal of most BCCs. The cure rate for this method, whether done by a plastic surgeon, family doctor, or dermatologist is totally dependent on the surgical margin. When standard surgical margin is applied (usually 4 mm or more)^[8], a high cure rate can be achieved with standard excision^[9][10] A dermatoscope dermatoscopy can help an experienced surgeon accurately identify the visible tumour that the naked eye can not see.^[11][12] The narrower the free margin (skin removed that is free of visible tumor) the higher the recurrence rate^{[13][14][15][16]}. A weakness with standard surgical excision is the high recurrence rate of basal cell cancers of the face, especially around eyelids^[17], nose, and facial structures. ^[18] A diagram on page 36 of the NCCN publication demonstrate the area of high risk of recurrence as most the face with the exception of the central cheek and upper forehead.^[9] On the face, or on recurrent basal cell cancer after previous surgery, special margin controlled processing (ccpdma - complete circumferential peripheral and deep margin assessment^[19])^[20] using frozen section histology (Mohs surgery is one of the methods) is required^[21][22]. With margin controlled frozen section histology, a surgeon can achieve a high cure rate and low recurrence rate on the same day of the excision^[23]. However, most standard excisions done in a plastic surgeon or dermatologist's office are sent to an outside laboratory for standard bread loafing method of processing^[24]. This method has a high "false negative" rate due to the random sampling of the tumour. It is likely that less than 5% of the surgical margin is examined, as each slice of tissue is only 6 microns thick, about 3 to 4 serial slices are obtained per section, and only about 3 to 4 sections are obtained per specimen (see figure 2 of reference^[25]). Usually, the rule of thumb is if a 4 mm free margin is obtained around a small tumor (less than 6mm), or a wider 6 mm free margin is obtained around a larger tumor (greater than 6mm), the cure rate is very high - 95% or better^[26][27][28]. For cosmetic reasons, many doctors take only very small surgical margins 1-2 mm^[29], especially when facial tumour is being removed. A pathology report from such a case indicating "margins free of residual tumour", often is inaccurate, and a high recurrence rate of up to 38% might occur ^{[8][17][29][30]}. When in doubt, a patient should demand that either Mohs surgery or frozen section histology with either margin control (ccpdma) or thin serial bread-loafing is utilized when dealing with a tumour on the face.^[9] The pathologist processing the frozen section specimen should cut multiple sections through the block to minimize the false negative error rate. Or one should simply process the tissue utilizing a method approximating the Mohs method (described in most basic histopathology text books or described in this reference ^[31]) during frozen section processing. Unfortunately, these methods are difficult when applied to frozen sections; and is very tedious to process. When not utilizing frozen section, the patient might have to wait a week or more, before informing the patient if more tumour is left, or if the surgical margin is too narrow^[32]. And a second surgery must be performed to remove the residual or potential residual tumour once the surgeon inform the patient of the positive or narrow surgical margin on the surgical pathology report.

• Mohs surgery: Mohs surgery (or Mohs micrographic surgery) is an outpatient procedure in which the tumor is surgically excised and then immediately examined under a microscope. It is claimed to have the highest cure rate of 97% to 99.8% by some individuals. The base and edges are microscopically examined to verify sufficient margins before the surgical repair of the site. If the margins are insufficient, more is removed from the patient until the margins are sufficient. It is also used for squamous cell carcinoma; however, the cure rate is not as high as Mohs surgery for basal cell carcinoma.

• Chemotherapy: Some superficial cancers respond to local therapy with 5-fluorouracil, a chemotherapy agent. Topical treatment with 5% Imiquimod cream, with five applications per week for six weeks has a reported 70-90% success rate at reducing, even removing, the BCC [basal cell carcinoma]. Both Imiquimod and 5-fluorouracil has received FDA approval for the treatment of superficial basal cell carcinoma. Off label use of imiquimod on invasive basal cell carcinoma has been reported. Imiquimod may be used prior to surgery in order to reduce the size of the carcinoma. One can expect a great deal of inflammation with this treatment^[33]. Chemotherapy often follows Mohs surgery to eliminate the residual superficial basal cell carcinoma after the invasive portion is removed. Some advocate the use of imiquimod prior to Mohs surgery to remove the superficial component of the cancer^[34] Removing the residual superficial tumor with surgery alone can result in large and difficult to repair surgical defects. One often waits a month or more after surgery before starting the Imiquimod or 5-fluorouracil to make sure the surgical wound has adequately healed. Some individual advocate the use of curettage (see EDC below) first, then followed by chemotherapy. These experimental procedure likely will result in better cure rate than one alone, but are not standard care.

• Immunotherapy: Immunotherapy research suggests that treatment using Euphorbia peplus, a common garden weed, may be effective^[35]. Australian biopharmaceutical company Peplin^[36] is developing this as topical treatment for BCC. Imiquimod or Aldara is an immunotherapy but is listed here under chemotherapy.

• Radiation: Radiation therapy is appropriate for all forms of BCC as adequate doses will eradicate the disease. Although radiotherapy is generally used in older patients who are not candidates for surgery, it is also used in cases where surgical excision will be disfiguring or difficult to reconstruct (especially on the tip of the nose, and the nostril rims). Radiation treatment often takes as few as 5 visits to as many as 25 visits for radiation therapy. Usually, the more visits scheduled for therapy, the less complication or damage is done to the normal tissue supporting the tumor. Cure rate can be as high as 95% for small tumor, or as low as 80% for large tumors. Usually, recurrent tumors after radiation are treated with surgery, and not with radiation. Further radiation treatment will further damage normal tissue, and the tumor might be resistant to further radiation.

• Photodynamic Therapy: Photodynamic therapy is a new modality for treatment of basal-cell carcinoma, which is administrated by application of photosensitizers to the target area. When these molecules are activated by light, they become toxic, therefore destroy the target cells. Methyl aminolevulinate is approved by EU as a photosensitizer since 2001. This therapy is also used in other skin cancer types^[37].

• Cryosurgery: Cryosurgery is an old modality for the treatment of many skin cancers. When accurately utilized with a temperature probe and cryotherapy instruments, it can result in very good cure rate. Disadvantages include lack of margin control, tissue necrosis, over or under treatment of the tumor, and long recovery time. Several textbooks are published on the therapy, and a few physicians still apply the treatment to selected patients.^[38]

• Electrodessication and curettage: or EDC is accomplished by using a round knife, or curette, to scrape away the soft cancer. The skin is then burned with an electric current. This further softens the skin, allowing for the knife to cut more deeply with the next layer of curettage. The cycle is repeated, with a safety margin of curettage of normal skin around the visible tumor. This cycle is repeated 3 to 5 times, and the free skin margin treated is usually 4 to 6 mm. Cure rate is very much user dependent and depends on the size and type of tumor. Infiltrative or morpheaform BCCs can be difficult to eradicate with EDC. Generally, this method is used on cosmetically unimportant areas like the trunk. Some physicians believe that it is acceptable to utilize EDC on the face of elderly patients over the age of 70. However, with increasing life expectancy, such an objective criteria can not be supported. The cure rate can be low or high, depending on the aggressiveness of the EDC and the free margin treated. Some advocates curettage alone without electrodessication, and with the same cure rate. ^[39]

Treating surgeons will recommend one of these modalities as appropriate treatment depending on the tumour size, location, patient age, and other variables.

Prognosis

Prognosis is excellent if the appropriate method of treatment is used in early primary basal cell cancers. Recurrent cancers are much harder to cure, with a higher recurrent rate with any methods of treatment. Although basal cell carcinoma rarely metastasizes, it grows locally with invasion and destruction of local tissues. The cancer can impinge on vital structures and result in loss of extension or loss of function or rarely death. The vast majority of cases can be successfully treated before serious complications occur. The recurrence rate for the above treatment options ranges from 50% to 1% or less.

Epidemiology

Basal cell cancer is the most common skin cancer. It is much more common in fair-skinned individuals with a family history of basal cell cancer and increases in incidence closer to the equator or at higher altitude. According to Skin Cancer Foundation, there are approximately 800,000^[40] new cases yearly in the United States alone. Up to 30% of caucasians develop basal cell carcinomas in their life time.^[3]

Most sporadic BCC arises in small numbers on sun-exposed skin of people over age 50, although younger people may also be affected. The development of multiple basal cell cancer at an early age could be indicative of Nevoid basal cell carcinoma syndrome.

Image gallery

References

1. ^ MedlinePlus Encyclopedia Basal cell carcinoma
2. ^ "Basal Cell Carcinoma - Symptoms, Treatment and Prevention". http://www.healthscout.com/ency/1/199/main.html. 
3. ^ ^{a b c d} Wong CS, Strange RC, Lear JT (October 2003). "Basal cell carcinoma". BMJ 327 (7418): 794–8. doi:10.1136/bmj.327.7418.794. PMID 14525881. 
4. ^ Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0071380760.
5. ^ James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0. 
6. ^ http://www.skincancerguide.ca/basal/what_is_basal_cell_cancer.html
7. ^ Epstein EH, Shepard JA, Flotte TJ (Jan 2008). "Case records of the Massachusetts General Hospital. Case 3-2008. An 80-year-old woman with cutaneous basal-cell carcinomas and cysts of the jaws". N Engl J Med 358 (4): 393–401. doi:10.1056/NEJMcpc0707893. PMID 18216361. 
8. ^ ^{a b} Wolf DJ, Zitelli JA (March 1987). "Surgical margins for basal cell carcinoma". Arch Dermatol 123 (3): 340–4. doi:10.1001/archderm.123.3.340. PMID 3813602. http://archderm.ama-assn.org/cgi/pmidlookup?view=long&pmid=3813602. 
9. ^ ^{a b c} http://www.nccn.org/professionals/physician_gls/PDF/nmsc.pdf
10. ^ Silverman MK, Kopf AW, Bart RS, Grin CM, Levenstein MS (June 1992). "Recurrence rates of treated basal cell carcinomas. Part 3: Surgical excision". J Dermatol Surg Oncol 18 (6): 471–6. PMID 1592998. 
11. ^ Scalvenzi M, Lembo S, Francia MG, Balato A (October 2008). "Dermoscopic patterns of superficial basal cell carcinoma". Int. J. Dermatol. 47 (10): 1015–8. doi:10.1111/j.1365-4632.2008.03731.x. PMID 18986346. 
12. ^ Cuellar F, Vilalta A, Puig S, Palou J, Zaballos P, Malvehy J (September 2008). "Dermoscopy of early recurrent basal cell carcinoma". Arch Dermatol 144 (9): 1254. doi:10.1001/archderm.144.9.1254. PMID 18794487. 
13. ^ Maloney ME, et al. (1999). Surgical Dermatopathology. Cambridge, MA: Blackwell Publishers. p. 110. ISBN 0-86542-299-0. 
14. ^ Kimyai-Asadi A, Katz T, Goldberg LH, et al. (December 2007). "Margin involvement after the excision of melanoma in situ: the need for complete en face examination of the surgical margins". Dermatol Surg 33 (12): 1434–9; discussion 1439–41. doi:10.1111/j.1524-4725.2007.33313.x. PMID 18076608. 
15. ^ Mosterd K, Krekels GA, Nieman FH, et al. (December 2008). "Surgical excision versus Mohs' micrographic surgery for primary and recurrent basal-cell carcinoma of the face: a prospective randomised controlled trial with 5-years' follow-up". Lancet Oncol. 9 (12): 1149–56. doi:10.1016/S1470-2045(08)70260-2. PMID 19010733. 
16. ^ Kimyai-Asadi A, Goldberg LH, Jih MH (September 2005). "Accuracy of serial transverse cross-sections in detecting residual basal cell carcinoma at the surgical margins of an elliptical excision specimen". J. Am. Acad. Dermatol. 53 (3): 469–74. doi:10.1016/j.jaad.2005.02.049. PMID 16112355. 
17. ^ ^{a b} Sigurdsson H, Agnarsson BA (August 1998). "Basal cell carcinoma of the eyelid. Risk of recurrence according to adequacy of surgical margins". Acta Ophthalmol Scand 76 (4): 477–80. doi:10.1034/j.1600-0420.1998.760416.x. PMID 9716337. 
18. ^ Farhi D, Dupin N, Palangié A, Carlotti A, Avril MF (October 2007). "Incomplete excision of basal cell carcinoma: rate and associated factors among 362 consecutive cases". Dermatol Surg 33 (10): 1207–14. doi:10.1111/j.1524-4725.2007.33255.x. PMID 17903153. http://www3.interscience.wiley.com/journal/118489368/abstract. 
19. ^ http://www.nccn.org/professionals/physician_gls/PDF/nmsc.pdf pages 6 and 7
20. ^ Dhingra N, Gajdasty A, Neal JW, Mukherjee AN, Lane CM (June 2007). "Confident complete excision of lid-margin BCCs using a marginal strip: an alternative to Mohs' surgery". Br J Ophthalmol 91 (6): 794–6. doi:10.1136/bjo.2006.109892. PMID 17229804. 
21. ^ Bentkover SH, Grande DM, Soto H, Kozlicak BA, Guillaume D, Girouard S (2002). "Excision of head and neck basal cell carcinoma with a rapid, cross-sectional, frozen-section technique". Arch Facial Plast Surg 4 (2): 114–9. doi:10.1001/archfaci.4.2.114. PMID 12020207. http://archfaci.ama-assn.org/cgi/pmidlookup?view=long&pmid=12020207. 
22. ^ Minton TJ (August 2008). "Contemporary Mohs surgery applications". Curr Opin Otolaryngol Head Neck Surg 16 (4): 376–80. doi:10.1097/MOO.0b013e3283079cac. PMID 18626258. http://journals.lww.com/co-otolaryngology/pages/articleviewer.aspx?year=2008&issue=08000&article=00013&type=abstract. 
23. ^ Nagore E, Grau C, Molinero J, Fortea JM (March 2003). "Positive margins in basal cell carcinoma: relationship to clinical features and recurrence risk. A retrospective study of 248 patients". J Eur Acad Dermatol Venereol 17 (2): 167–70. doi:10.1046/j.1468-3083.2003.00535.x. PMID 12705745. http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0926-9959&date=2003&volume=17&issue=2&spage=167. 
24. ^ Lane JE, Kent DE (2005). "Surgical margins in the treatment of nonmelanoma skin cancer and mohs micrographic surgery". Curr Surg 62 (5): 518–26. doi:10.1016/j.cursur.2005.01.003. PMID 16125611. 
25. ^ Maloney ME, et al. (1999). "Determining Cancer at Surgical margin". Surgical Dermatopathology. Cambridge, MA: Blackwell Publishers. p. 113. ISBN 0-86542-299-0. 
26. ^ Skin Malignancies, Squamous Cell Carcinoma at eMedicine
27. ^ Staub G, Revol M, May P, Bayol JC, Verola O, Servant JM (October 2008). "[Excision skin margin and recurrence rate of skin cancer: a prospective study of 844 cases]" (in French). Ann Chir Plast Esthet 53 (5): 389–98. doi:10.1016/j.anplas.2007.07.015. PMID 17961898. 
28. ^ http://www.bccancer.bc.ca/HPI/CancerManagementGuidelines/Skin/NonMelanoma/ManagementPolicies/start.htm
29. ^ ^{a b} Griffiths RW, Suvarna SK, Stone J (2007). "Basal cell carcinoma histological clearance margins: an analysis of 1539 conventionally excised tumours. Wider still and deeper?". J Plast Reconstr Aesthet Surg 60 (1): 41–7. doi:10.1016/j.bjps.2006.06.009. PMID 17126265. 
30. ^ Hauben DJ, Zirkin H, Mahler D, Sacks M (January 1982). "The biologic behavior of basal cell carcinoma: analysis of recurrence in excised basal cell carcinoma: Part II". Plast. Reconstr. Surg. 69 (1): 110–6. PMID 7053498. 
31. ^ Bentkover SH, Grande DM, Soto H, Kozlicak BA, Guillaume D, Girouard S (2002). "Excision of head and neck basal cell carcinoma with a rapid, cross-sectional, frozen-section technique". Arch Facial Plast Surg 4 (2): 114–9. doi:10.1001/archfaci.4.2.114. PMID 12020207. http://archfaci.ama-assn.org/cgi/pmidlookup?view=long&pmid=12020207. 
32. ^ http://gateway.nlm.nih.gov/MeetingAbstracts/ma?f=102272107.html
33. ^ [1]
34. ^ Butler DF, Parekh PK, Lenis A (January 2009). "Imiquimod 5% cream as adjunctive therapy for primary, solitary, nodular nasal basal cell carcinomas before Mohs micrographic surgery: a randomized, double blind, vehicle-controlled study". Dermatol Surg 35 (1): 24–9. doi:10.1111/j.1524-4725.2008.34378.x. PMID 19018814. 
35. ^ Peplin's skin cancer gel trial a success - Breaking News - Business - Breaking News
36. ^ Peplin
37. ^ Peng Q, Juzeniene A, Chen J, et al. (2008). "Lasers in Medicine". Rep. Prog. Phys. 71 (056701): 056701. doi:10.1088/0034-4885/71/5/056701. 
38. ^ http://www.webmd.com/cancer/cryosurgery-for-nonmelanoma-skin-cancer
39. ^ Barlow JO, Zalla MJ, Kyle A, DiCaudo DJ, Lim KK, Yiannias JA (June 2006). "Treatment of basal cell carcinoma with curettage alone". J. Am. Acad. Dermatol. 54 (6): 1039–45. doi:10.1016/j.jaad.2006.01.041. PMID 16713459. 
40. ^ Skin Cancer Foundation: Basal Cell Carcinoma

External links

• The Skin Cancer Foundation
• Natural history of Basal cell carcinoma

v • d • e Diseases of the skin and appendages by morphology Growths Epidermal wart · callus · seborrheic keratosis · acrochordon · molluscum contagiosum · actinic keratosis · squamous cell carcinoma · basal cell carcinoma · merkel cell carcinoma · nevus sebaceous · trichoepithelioma Pigmented Freckles · lentigo · melasma · nevus · melanoma Dermal and subcutaneous epidermal inclusion cyst · hemangioma · dermatofibroma · keloid · lipoma · neurofibroma · xanthoma · Kaposi's sarcoma · infantile digital fibromatosis · granular cell tumor · leiomyoma · lymphangioma circumscriptum · myxoid cyst Rashes With epidermal involvement Eczematous contact dermatitis · atopic dermatitis · seborrheic dermatitis · stasis dermatitis · lichen simplex chronicus · Darier's disease · glucagonoma syndrome · langerhans cell histiocytosis · lichen sclerosus · pemphigus foliaceus · Wiskott-Aldrich syndrome · Zinc deficiency Scaling psoriasis · tinea (corporis · cruris · pedis · manuum · faciei) · pityriasis rosea · secondary syphillis · mycosis fungoides · systemic lupus erythematosus · pityriasis rubra pilaris · parapsoriasis · ichthyosis Blistering herpes simplex · herpes zoster · varicella · bullous impetigo · acute contact dermatitis · pemphigus vulgaris · bullous pemphigoid · dermatitis herpetiformis · porphyria cutanea tarda · epidermolysis bullosa simplex Papular scabies · insect bite reactions · lichen planus · miliaria · keratosis pilaris · lichen spinulosus · transient acantholytic dermatosis · lichen nitidus · pityriasis lichenoides et varioliformis acuta Pustular acne vulgaris · acne rosacea · folliculitis · impetigo · candidiasis · gonococcemia · dermatophyte · coccidioidomycosis · subcorneal pustular dermatosis Hypopigmented tinea versicolor · vitiligo · pityriasis alba · postinflammatory hyperpigmentation · tuberous sclerosis · idiopathic guttate hypomelanosis · leprosy · hypopigmented mycosis fungoides Without epidermal involvement Red Blanchable Erythema Generalized drug eruptions · viral exanthems · toxic erythema · systemic lupus erythematosus Localized cellulitis · abscess · boil · erythema nodosum · carcinoid syndrome · fixed drug eruption Specialized urticaria · erythema (multiforme · migrans · gyratum repens · annulare centrifugum · ab igne) Nonblanchable Purpura Macular thrombocytopenic purpura · actinic purpura Papular disseminated intravascular coagulation · vasculitis Indurated scleroderma/morphea · granuloma annulare · lichen sclerosis et atrophicus · necrobiosis lipoidica Miscellaneous disorders Ulcers Hair telogen effluvium · androgenic alopecia · trichotillomania · alopecia areata · systemic lupus erythematosus · tinea capitis · loose anagen syndrome · lichen planopilaris · folliculitis decalvans · acne keloidalis nuchae Nail onychomycosis · psoriasis · paronychia · ingrown nail Mucous membrane aphthous stomatitis · oral candidiasis · lichen planus · leukoplakia · pemphigus vulgaris · mucous membrane pemphigoid · cicatricial pemphigoid · herpesvirus · coxsackievirus · syphilis · systemic histoplasmosis · squamous cell carcinoma

v • d • e Glandular and epithelial neoplasms (ICD-O 8010-8589) Epithelium Papilloma/carcinoma (8010-8139) Small cell carcinoma · Verrucous carcinoma · Squamous cell carcinoma · Basal cell carcinoma · Transitional cell carcinoma · Inverted papilloma Glands Adenomas/ adenocarcinomas (8140-8429) Gastrointestinal tract: Linitis plastica · Familial adenomatous polyposis pancreas (Insulinoma, Glucagonoma, Gastrinoma, VIPoma, Somatostatinoma) Cholangiocarcinoma · Klatskin tumor · Hepatocellular adenoma/Hepatocellular carcinoma Urogenital Renal cell carcinoma · Endometrioid tumor · Renal oncocytoma Endocrine Prolactinoma · Multiple endocrine neoplasia · Adrenocortical adenoma/Adrenocortical carcinoma · Hurthle cell Other/multiple Neuroendocrine tumor (Carcinoid) · Adenoid cystic carcinoma · Oncocytoma · Clear cell adenocarcinoma · Apudoma · Cylindroma · Papillary hidradenoma Adnexal and skin appendage (8390-8429) sweat gland (Hidrocystoma, Syringoma) · Syringocystadenoma papilliferum Cystic, mucinous, and serous (8440-8499) Cystic general Cystadenoma/Cystadenocarcinoma Mucinous Signet ring cell carcinoma (Krukenberg tumor) · Mucinous cystadenoma/Mucinous cystadenocarcinoma (Pseudomyxoma peritonei) · Mucoepidermoid carcinoma Serous Serous cystadenoma/Serous cystadenocarcinoma/Papillary serous cystadenocarcinoma Ductal, lobular, and medullary (8500-8549) Ductal carcinoma Mammary ductal carcinoma · Pancreatic ductal carcinoma · Comedocarcinoma · Paget's disease of the breast/Extramammary Paget's disease Lobular carcinoma Lobular carcinoma in situ · Invasive lobular carcinoma Medullary carcinoma Medullary carcinoma of the breast · Medullary thyroid cancer Acinar cell (8550-8559) Acinic cell carcinoma Other Complex epithelial (8560-8589) Warthin's tumor · Thymoma

v • d • e Tumors: skin cancer (C43-C44/D22-D23, 172-173/216) Epidermis Basal cell carcinoma · Squamous cell carcinoma (Acanthoma) Bowen's disease Dermis Benign fibrous histiocytoma/dermatofibrosarcoma · Dermatofibrosarcoma protuberans Nevi and melanomas Nevus: Melanocytic nevus · Dysplastic nevus · Halo nevus · Spitz nevus Melanoma: Superficial spreading melanoma · Nodular melanoma · lentigo (Lentigo maligna/Lentigo maligna melanoma, Acral lentiginous melanoma) integument, SF, LCT navs: anat/physio, noncongen/congen/neoplasia, symptoms+signs/eponymous, proc

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