title: Estrogen receptor positive breast cancer identified by 95-gene classifier as at high risk for relapse shows better response to neoadjuvant chemotherapy.
abstract: A 95-gene classifier (95-GC) recently developed by us can predict the risk of relapse for ER-positive and node-negative breast cancer patients with high accuracy. This study investigated association of risk classification by 95-GC with response to neoadjuvant chemotherapy (NAC). Tumor biopsy samples obtained preoperatively from 72 patients with ER-positive breast cancer were classified by 95-GC into high-risk and low-risk for relapse. Pathological complete response (pCR) rate was numerically higher for high-risk (15.8%) than low-risk patients (8.8%) although the difference was not statistically significant. Pathological response evaluated in terms of the pathological partial response (pPR) rate (loss of tumor cells in more than two-thirds of the primary tumor) showed a significant association (P=0.005) between the high-risk patients and a high pPR rate. Besides, external validation study using the public data base (GSE25066) showed that the pCR rate (16.4%) for high-risk patients (n=128) was significantly (P=0.003) higher than for low-risk patients (5.7%) (n=159). These results demonstrate that the high-risk patients for relapse show a higher sensitivity to chemotherapy and thus are likely to benefit more from adjuvant chemotherapy.
authors.affiliation: Department of Breast and Endocrine Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Tsunashima
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Naoi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Kishi
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Baba
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shimomura
authors.forename: Naomi
authors.initials: N
authors.lastname: Maruyama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakayama
authors.forename: Kenzo
authors.initials: K
authors.lastname: Shimazu
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Noguchi
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D009364:Neoplasm Recurrence, Local; D011960:Receptors, Estrogen / Q000378:metabolism*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D011960:Receptors, Estrogen