[Tumor tissue aromatase and estrogen levels versus clinical course of endometrial cancer].

Levels of aromatase, a key enzyme in estrogen biosynthesis, were assayed in tumor tissue sampled from 25 patients with endometrial cancer. In addition, estradiol concentrations were compared in normal and altered endometrial tissue from 78 patients suffering uterine cancer. Unlike breast cancer, aromatase was not detectable in altered endometrium unless tissue estrogens could be identified in both normal and tumor tissue. Hence, aromatase presence served as an indicator of malignant transformation. Its concentration in samples of uterine tissue varied 0-28.4 fM/mg protein/hr (an average of 12.9(1.7 fM/mg protein/hr). There was hardly any correlation between this level, on the one hand, and menopause and body mass, on the other. Yet, it tended to increase in step with stage of disease and cell differentiation decline. Estradiol concentrations in malignant endometrium in both reproductive and menopausal patients were higher than in macroscopically normal ones, while still cycling women tended to show higher values than menopausal ones. Although there was no significant difference in estradiol levels in the altered endomentrium of patients with pathogenetical patterns of uterine cancer stage I and II, they did show a direct correlation with clinical stage of tumor process and depth of invasion into the underlying myometrium. Hence, unlike estrogens circulating in blood, those contained in tissue ("intratumor") ones did enhance the aggressiveness of endometrial cancer course. It will be for further investigations to show whether it is due to an estrogen fraction being carried away by tumor from the circulation, or estrogens being synthesized by aromatase in tumor itself.