Primary Peritoneal Carcinoma - Peritoneal Cancer

Primary peritoneal cancer or carcinoma is also known as serous surface papillary carcinoma, primary peritoneal carcinoma, extra-ovarian serous carcinoma, primary serous papillary carcinoma, psammomacarcinoma. It was historically classified under "carcinoma of unknown primary" (CUP). Primary peritoneal cancer (PPC, or PPCa) is a cancer of the cells lining the peritoneum, or abdominal cavity.

Some studies indicate that up to 15% of serous ovarian cancers are thought to be actually primary peritoneal carcinomas in origin.

Histomorphological and molecular biological characteristics suggest that serous carcinomas, which include ovarian serous carcinoma, uterine serous carcinoma, Fallopian tube serous carcinoma, cervical serous carcinoma, and primary peritoneal serous carcinoma really represent one entity.

Theory

Ovarian and peritoneal epithelium share common embryonal origin, the coelomic epithelium (mesodermal origin). Coelomic epithelium is thought to be of mesonephric origin. With the overall point being that normal ovarian and peritoneal tissue is derived from the mesonephros. On the contrary, fallopian tube epithelium, endometrium and endocervix are related to paramesonephros (Müllerian duct). Surprisingly, epithelial ovarian cancer and primary peritoneal cancer are histologically similar to the Mullerian epithelium; not their embryonal origin, the mesonephros. Either a metaplasia has occurred or Mullerian remnants have been left behind in coelemic epithelium, which have turned oncogenic.

Genetic causes

Although the precise causes are not known, a link with certain variants of BRCA1/2 has been described. 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.

An association with vascular endothelial growth factor has been observed.

Prognosis and treatment

Prognosis and treatment is the same as for the most common type of ovarian cancer, which is epithelial ovarian cancer.

The median survival of primary peritoneal carcinomas is usually shorter by 2â€"6 months time when compared with serous ovarian cancer. Studies show median survival varies between 11.3â€"17.8 months. One study reported 19-40 month median survival (95% CI) with a 5-year survival of 26.5%.

Elevated albumin levels have been associated with a more favorable prognosis.

References

External links

• Description at Cancer Research UK