Serum levels of placental protein 10 (PP10) in women with breast cancer and genital carcinoma and in healthy male and female subjects.

PP10, a recently characterized glycoprotein from human placenta, was studied using a specific double-antibody radioimmunoassay in the serum of about 100 volunteers and 200 cancer patients. Elevated levels (greater than 20 nU/ml) were found in 87% of patients with primary breast cancer, in 100% of those with primary genital tumours and in 78% of patients with recurrent disease. PP10 was also measured in tumour extracts and in some patients with benign tumours. The serum concentration decreased within a few weeks after removal of the tumour. There were no significant correlations of the PP10 level with age, tumour size, histological grading or lymph node involvement. Sequential determinations of PP10 during cytostatic therapy sometimes showed rising levels accompany the development of metastases. PP10 can be regarded as a tumour associated protein and a tumour marker in gynaecological practice.