title: Tamoxifen with ovarian function suppression versus tamoxifen alone as an adjuvant treatment for premenopausal breast cancer: a meta-analysis of published randomized controlled trials.
abstract: BACKGROUND
  Ovarian function suppression (OFS) significantly downregulates the concentration of plasma estrogens. However, it is unclear whether it offers any survival benefits if combined with adjuvant tamoxifen treatment in premenopausal women. This meta-analysis was designed to assess data from previous studies involving adjuvant tamoxifen treatment plus OFS in premenopausal breast cancer.
  
  
  METHODS
  Electronic literature databases (PubMed, Embase, the Web of Science, and the Cochrane Library) were searched for relevant randomized controlled trials published prior to February 1, 2015. Only randomized controlled trials that compared tamoxifen alone with tamoxifen plus OFS for premenopausal women with breast cancer were selected. The evaluated endpoints were disease-free survival and overall survival.
  
  
  RESULTS
  Four randomized controlled trials comprising 6,279 patients (OFS combination, n=3,133; tamoxifen alone, n=3,146) were included in the meta-analysis. There was no significant improvement in disease-free survival or overall survival with addition of OFS in either the whole population or the hormone receptor-positive subgroup. The risk of distant recurrence was not reduced with the addition of OFS in the whole population. A subgroup analysis showed that addition of OFS significantly improved overall survival in patients who were administered chemotherapy.
  
  
  CONCLUSIONS
  Based on the available studies, concurrent administration of OFS and adjuvant tamoxifen treatment for premenopausal women with breast cancer has no effect on prolonging disease-free survival and overall survival, excluding patients who were administered chemotherapy. It should not be widely recommended, except perhaps for women who were hormone-receptor positive and who were also administered adjuvant chemotherapy.
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, People's Republic of China.
authors.forename: Shunchao
authors.initials: S
authors.lastname: Yan
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, Shenyang Chest Hospital, Shenyang, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiao
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, People's Republic of China.
authors.forename: Huawei
authors.initials: H
authors.lastname: Zou
keywords: adjuvant treatment; breast cancer; meta-analysis; ovarian function suppression; premenopausal women; tamoxifen