Value of endometrial thickness in diagnosis of endometrial hyperplasia during selective estrogen receptor modulator therapy in premenopausal breast cancer patients

Objective The weak estrogenic-like effect of selective estrogen receptor modulator (SERM) may lead to series of endometrial lesions, including proliferation, hyperplasia, polyp formation, and even endometrial cancer. This study aimed to explore the effectiveness of different endometrial thickness in diagnosis of endometrial hyperplasia during SERM therapy in premenopausal patients. Methods The clinical data of 115 patients receiving hysteroscopic endometrial biopsy during SERM therapy in Peking Union Medical College Hospital, China from January 2010 to December 2018 were retrospectively analyzed. Results Average age at the beginning of SERM therapy was 43.4 ± 5.7 years old. Mean duration time of SERM therapy was 31.0 ± 22.1 months. The mean endometrial thickness was 14.3 ± 6.1 mm. 4 cases of atypical endometrial hyperplasia (3.5 %), and 4 cases of endometrial hyperplasia without atypia (3.5 %) were detected. Endometrial thickness was higher in endometrial hyperplasia patients than in no endometrial hyperplasia patients (18.8 vs 13.9 mm, p = 0.029). Endometrial thickness in 8 out of 8 endometrial hyperplasia patients and 38 out of 107 no endometrial hyperplasia patients were ≥ 15 mm (p = 0.002). The negative predictive value in the diagnosis of endometrial hyperplasia during SERM therapy in premenopausal patients was 100 % when endometrial thickness Conclusion Endometrial hyperplasia was less likely to occur in premenopausal patients during SERM therapy when endometrial thickness