DNA-content in endometrial carcinoma of tamoxifen-treated breast cancer patients.

DNA measurements and histopathologic evaluation were performed in 17 patients treated with adjuvant tamoxifen for early breast cancer and who developed endometrial carcinoma during or after the tamoxifen therapy. The tumors were exclusively characterized by euploid DNA content except for two cases, one mixed mesodermal sarcoma, a highly malignant and rare tumor, and one adenocarcinoma. Although the use of adjuvant tamoxifen therapy most likely enhances the risk of developing endometrial carcinoma, the beneficial effects of adjuvant breast cancer treatment is of well-known clinical importance. The hazards of giving long-term tamoxifen seem to be low since the endometrial tumors were associated with low-grade malignancy and euploid DNA pattern.