COMMON ENDOMETRIAL DECIDUAL REACTION IN POSTMENOPAUSAL BREAST-CANCER PATIENTS TREATED WITH TAMOXIFEN AND PROGESTOGENS

In order to assess endometrial reaction to the combined treatment of t amoxifen acid progestogens in asymptomatic postmenopausal breast cance r patients, we evaluated all such patients by vaginal ultrasonography and by histological examination of endometrial samplings. All patients were initially treated with tamoxifen, and progestogens were then add ed when metastases became evident. Of 12 patients included in the stud y, eight (66.66%) showed evidence of strong endometrial stromal decidu alization, while three (25%) had decidual reactions in endometrial pol yps. Overall, 11 (91:66%) of the patients had decidual reactions, and all were treated with progestogens for greater than or equal to 3 cons ecutive months. One patient, treated with progestogens for 1 month, ha d an inactive endometrium. All but three had thickened endometria (>10 mm) on ultrasonographic evaluation. These data show that postmenopaus al breast cancer patients who received progestogens for greater than o r equal to 3 months, and who concomitantly took tamoxifen, had a unifo rm decidual reaction in all uteri.