[Histopathological changes in endometrial cancer treated with tamoxifen]

Eight cases of endometrial adenocarcinoma, including 7 well differentiated cases (stage Ia three, stage Ib three, stage II one) and I poorly differentiated case (stage IVb), were treated with Tamoxifen (20 mg/day) for 7-14 days. The average age of these patients was 59.1 +/- 10.9 years old and they were all postmenopausal for between 6 months and 30 years. The endometrial tissue was biopsied before Tamoxifen administration and half of it was investigated for progestin receptor (PR) and estrogen receptor (ER) while the remainder was used for histopathological examination. After surgical treatment, some tissue fragments of the endometrium were taken for investigation of PR and ER. The effect of Tamoxifen was then studied for the amount of PR, ER and histopathology. The result was that the amount of PR was increased in well differentiated cases whereas it was unchanged in poorly differentiated ones, and the amount of ER was decreased in all cases. Meanwhile, obvious histopathological changes were noted as follows decrease of glandular epithelial stratification, increased secretory activity, increased epithelial cell size with columnar cell type, increase of transparent, vacuolated cytoplasm, increase of nuclear size with variable shape and prominent nucleoli with marginal aggregation of chromatin. However, no stromal change was noted. Furthermore, the greater the increase in the amount of PR, the more conspicuous histopathological change was noted. It was concluded that Tamoxifen could produce both functional (PR, ER) and morphological (histopathology) changes in endometrial cancers.