Progesterone as a possible tumor marker for "nonendocrine" ovarian malignant tumors.

Fifty-one postmenopausal or oophorectomized women with cancer of the ovary were studied. The histologic types were IC, IIC, IIIC, V, and FIGO Stages I-IV. Their tumor volumes were evaluated once a month using bimanual recto-vaginal palpation under anesthesia. Blood samples were drawn for progesterone radioimmunoassay at monthly intervals for 4 months. The plasma levels were compared with those of a control group of postmenopausal women and a control group of fertile women in the follicular phase of the menstrual cycle. The results show a relationship between tumor volume and plasma progesterone level. Histologic type and FIGO stage seem to be less important. During chemotherapy the plasma progesterone value decreased with the reduction in tumor volume. Women bilaterally oophorectomized and radically operated showed a lower plasma progesterone level than both the control groups, which indicates significant progesterone production in the postmenopausal ovary. The results suggest that progesterone may be used as a tumor marker in "nonendocrine" ovarian tumors.