It was historically classified under "carcinoma of unknown primary" (CUP).

[4] Furthermore, women with BRCA1/2 mutation have a 5% risk of developing primary peritoneal cancer even after prophylactic oophorectomy.

Primary peritoneal carcinoma shows similar rates of tumor suppressor gene dysfunction (p53, BRCA, WT1) as ovarian cancer and can also show an increased expression of HER-2/neu.

[6][7] The median survival of primary peritoneal carcinomas is usually shorter by 2–6 months time when compared with serous ovarian cancer.

[medical citation needed] Elevated albumin levels have been associated with a more favorable prognosis.