A diagnosis of stage 3 peritoneal cancer is severe because the cancer has spread from the lining of the pelvis and abdomen to another organ, such as the liver or spleen, according to the American Cancer Society. Doctors stage peritoneal cancer by testing tissue samples of pelvic and other organs.
Peritoneal cancer is a gynecologic cancer related to ovarian and fallopian tube cancer, states WebMD. Treatment options include surgery and chemotherapy. Prognosis and survival rates for stage 4 peritoneal cancer vary depending upon the type of carcinoma and the method of treatment, claims a 2004 study published by the National Institutes of Health.