Factors related to adjuvant ovarian function suppression in premenopausal breast cancer patients

Objective To analyze the applied condition of ovary function suppression (OFS) before and after joint analysis of TEXT and SOFT trials and SOFT trial, and to identify the relevant factors of OFS usage. Methods The analysis was performed in premenopausal women with hormone receptor (HR) positive breast cancer receiving surgical treatment from Apr 2013 to Oct 2015 in Ruijin Hospital, Shanghai Jiaotong University School of Medicine. Adjuvant treatment strategy was made in the multidisciplinary team (MDT) meetings. We analyzed the applied condition of OFS before and after joint analysis, SOFT trial and its relevant factors. Results Among 454 patients, 114 (25.1%) patients received OFS. Before the results of joint analysis came out, all the patients (38/38) received OFS together with tamoxifen (TAM); after the results came out, clinicians began to put OFS with exemestane into practice, among 76 patients, 41(53.9%) patients received OFS with exemestane while 35 (46.1%) patients received OFS together with TAM. Before the results of SOFT trial came out, 71 out of 310 (22.9%) patients received OFS while 43 out of 144 (29.9%) patients received OFS after that. No significant difference was found between the proportion of patients receiving OFS before and after the results of SOFT trial came out (P=0.112). Age, histological grade, pN status, Ki-67 status, molecular subtype and acceptance of chemotherapy were correlated with OFS treatment (P<0.05). Age, tumor grade and pN were independent significant predictors of OFS usage. Conclusions After the results of joint analysis came out, clinicians began to apply OFS with exemestane to premenopausal women with HR positive breast cancer. There is no significant difference between the proportion of patients receiving OFS before and after SOFT trial. Age, tumor grade and pN status are independent significant predictors of OFS treatment. Patients younger than 40, with histological grade Ⅱ or Ⅲ tumor and with pN1 or pN2 status are prone to receive OFS. Key words: Breast neoplasms; Neoadjuvant therapy; Ovary function suppression; Factor analysis, statistical