Analysis of the effect and safety of levonorgestrel-releasing intrauterine system on patients with breast cancer who take tamoxifen

Objective To analyze the effect and safety of levonorgestrel-releasing intrauterine system(LNG-IUS) for the premenopausal patients with breast cancer who took tamoxifen as adjuvant therapy. Methods From June 2014 to June 2016, 84 patients with breast cancer who met the inclusion criteria in the First People′s Hospital of Xiaoshan District were randomly divided into two groups according to the digital table.The treatment group (39 cases) underwent LNG-IUS insertion, while the control group (45 cases) received no LNG-IUS insertion.The general condition of patients before the use of tamoxifen and LNG-IUS was evaluated.Transvaginal ultrasound was used to measure the thickness of endometrium, hysteroscope was used for pathological examination of endometrium and the measurement of ER/PR expression, and blood lipid level was also detected.All above was done before the treatment of tamoxifen and LNG-IUS, 1 year after treatment and 2 years after treatment. Results Before the therapy, there were no statistically significant differences between the two groups in general condition and uterine cavity condition(all P>0.05). After 1 year, the incidences of endometrial polyp, endometrial hyperplasia/secretion, benign lesion and endometrial atrophy in the treatment group were 2.6%, 5.1%, 15.4%, 76.9%, respectively, which in the control group were 6.7%, 20.0%, 17.8%, 55.6%, respectively.the differences between the two groups were statistically significant(χ2=4.06, 4.22, all P<0.05). After 2 years, the incidences of endometrial polyp, endometrial hyperplasia/secretion, benign lesion and endometrial atrophy in the treatment group were 0.0%, 2.6%, 84.6%, respectively, which in the control group were 11.1%, 15.6%, 60.0%, respectively, the differences between the two groups were statistically significant(χ2=4.608, 4.092, 6.203, all P<0.05). Conclusion LNG-IUS can prevent the benign endometrial lesions of breast cancer patients caused by tamoxifen therapy after surgery, and can decrease the incidence of endometrial polyp and endometrial hyperplasia/secretion, while increase the incidence of endometrial atrophy, without increasing the recurrence risk of breast cancer. Key words: Intrauterine devices, Medicated; Levonorgestrel; Tamoxifen; Breast neoplasms; Premenopause; Endometrium