From the symptoms described in Roots: The Next Generation, I would assume it was Ovarian or Uterine Cancer.
1967
Helen Palmer - archer - was born in 1974.
Renzo Palmer died on June 4, 1988, in Milan, Lombardy, Italy of cancer.
Dr. Seuss's first wife, Helen Palmer Geisel, died of cancer in 1967. Her illness and eventual passing had a profound impact on him, as they had been married for over 40 years. Helen was not only his wife but also a significant influence on his work, encouraging his creative pursuits throughout their marriage. Her death marked a deeply emotional period in his life.
Helmut Palmer died on December 24, 2004, in Tbingen, Baden-Wrttemberg, Germany of cancer.
Maria Palmer died on September 6, 1981, in Los Angeles, California, USA of cancer.
Reese Palmer died on October 27, 2011, in Clinton, Maryland, USA of prostate cancer.
her name was Helen Palmer
Helen Palmer - publisher - was born on 1917-05-09.
Helen Palmer Geisel was born on 1899-09-11.
Elida Gay Palmer died on April 16, 1995, in Buenos Aires, Argentina of cancer.
Helen Vita died on February 16, 2001, in Berlin, Germany of cancer.