Cancer is found in one or both ovaries or fallopian tubes. Stage I is divided into stages IA, IB, and IC. In stage IA, cancer is found inside a single ovary or fallopian tube. In stage IB, cancer is found inside both ovaries or fallopian tubes. In stage IC, cancer is found inside one or both ovaries or fallopian tubes and one of the following is true: (1) cancer is also found on the outside surface of one or both ovaries or fallopian tubes; or (2) the capsule (outer covering) of the ovary has ruptured (broken open); or (3) cancer cells are found in the fluid of the peritoneal cavity (the body cavity that contains most of the organs in the abdomen) or in washings of the peritoneum (tissue lining the peritoneal cavity).