The five-year survival rate for patients with stage III epithelial ovarian cancer ranges from 39 to 56 percent, according to the American Cancer Society. The rate increases to 92 percent if the cancer is found and treated prior to stage IC, when it spreads outside the ovary.
At stage III, the cancer is found in one or both ovaries and the lining of the abdomen or has spread to lymph nodes in the abdomen, explains Healthline. At stage IIIA, the cancer is also found in other pelvic organs and in lymph nodes within the abdominal cavity or abdominal lining. In IIIB, the disease has spread to nearby organs within the pelvis and cells may be present on the outside of the spleen, liver or lymph nodes, while larger deposits of cells found outside the spleen, liver or lymph nodes indicate stage IIIC.