Long-term effects of levonorgestrel-releasing intrauterine system on tamoxifen-treated breast cancer patients: a meta-analysis.
OBJECTIVE
The aim of the study is to assess the efficacy of the levonorgestrel-releasing intrauterine system (LNG-IUS) on the tamoxifen-induced endometrial lesions in breast cancer patients.


METHODS
PubMed and EMBASE databases were searched for eligible studies. Odds ratios were obtained to estimate the association between the LNG-IUS and tamoxifen-induced endometrial lesions. The fixed effects or random-effects model was used to combine data depending on heterogeneity.


RESULTS
With three eligible randomized clinical trials involving 359 patients, this analysis demonstrated tamoxifen-treated breast cancer patients using the LNG-IUS derived benefit from de novo polyps prevention (P < 0.0001, OR 0.18, 95% CI: 0.08-0.42). However, the LNG-IUS only showed a trend of maintaining endometrial proliferation or secretory status (P = 0.05, OR 0.36, 95% CI 0.13-1.02) and no statistical difference in atrophic or inactive changes (P = 0.13, OR 0.24, 95% CI 0.04-1.53) or endometrial hyperplasia without atypia (P = 0.08, OR 0.20, 95% CI 0.04-1.18). The LNG-IUS didn't have an increased incidence in breast cancer recurrence (P = 0.28, OR 1.75, 95% CI: 0.64-4.80) and cancer-induced death (P = 0.71, OR 1.22, 95% CI: 0.42-3.52). Bleeding in the treatment group was statistically more frequent than that in the control group (OR 6.20, 95% CI: 2.99-12.85, P < 0.00001).


CONCLUSIONS
This analysis verifies the efficacy of the LNG-IUS in preventing tamoxifen-induced polyps. The LNG-IUS didn't have an increased incidence in breast cancer recurrence and cancer-induced death. Long-term, large randomized studies of the LNG-IUS will be necessary to determine the benefit and risk in tamoxifen-treated breast cancer patients.
Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine Shanghai, China.
Yun
Y
Fu
Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine Shanghai, China.
Zhigang
Z
Zhuang
D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality; D016009:Chi-Square Distribution; D016889:Endometrial Neoplasms / Q000139:chemically induced / Q000401:mortality / Q000473:pathology / Q000517:prevention & control*; D004717:Endometrium / Q000187:drug effects* / Q000473:pathology; D004965:Estrogen Antagonists / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel / Q000008:administration & dosage* / Q000009:adverse effects; D009364:Neoplasm Recurrence, Local; D016017:Odds Ratio; D011127:Polyps / Q000139:chemically induced / Q000401:mortality / Q000473:pathology / Q000517:prevention & control*; D012307:Risk Factors; D013629:Tamoxifen / Q000009:adverse effects*; D016896:Treatment Outcome
D004965:Estrogen Antagonists; D013629:Tamoxifen; D016912:Levonorgestrel
Breast cancer; LNG-IUS; endometrial lesion; tamoxifen