a soficus is a part of the body belonging to the throat
The throat
Soficus (esophagus) cancer is cancer of the esophagus, the tube in the chest. The effects of esophagus cancer can be heart burn if the cancer is closer to the stomach. If the cancer is closer to the lungs it can affect breathing.
You may have misheard what was said to you and probably mean the esophagus. The esophagus is the "food tube" leading from the throat to the stomach, and like any other tissue in the body, it can be susceptible to cancer.
You might mean the esophagus. That is the tube between the throat and the stomach. The root phag+ means swallow or eat, and the phagus is the flap that pushes food down when you swallow. The prefix "eso-" means "out from," so the esophagus leads out from the phagus.