Staging classification for cancer of the ovary, fallopian tube, and peritoneum Ovarian cancer is the seventh most common cancer diagnosis among women worldwide, and the fifth most common cancer diagnosis among women in higher-resource regions [1]. The world rate is estimated to be 6.3 per 100 000 women, and is highest in high-resource countries (9.3 per 100 000 women) [1]. Primary peritoneal cancer and primary fallopian tube cancer are rare malignancies but share many similarities with ovarian cancer. Clinically, these 3 cancers are managed in a similar manner [2].