Placental Proteins (Pp 5, Pp 12 and Pp 14) in Ovarian Tumors: A Preliminary Report

Using a specific radio-immunoassay, the placental proteins PP 12, PP 14 and PP 5 were studied in serum for 2 patients with ovarian cancer and 7 with benign ovarian tumor. Elevated levels of PP 14, found in one endometroid ovarian cancer, decreased during successful treatment. PP 14 could also be found in the blood of nude mice grafted with this tumor. One patient with serous kystadenocarcinoma had a slightly elevated level of PP 14 at diagnosis, increasing as the tumor progressed. PP 14 was demonstrated histochemically in both the original tumor and the grafted. Ascitic fluid was rich in PP 14. Elevated levels of the proteins PP 12 and PP 5 were not found in these patients, however. In seven benign ovarian tumours, low PP 14 serum levels were found. The conclusion drawn from this study is that PP 14 can constitute a tumor marker in ovarian cancer.