title: Survival outcome and reduction rate of Ki-67 between pre- and post-neoadjuvant chemotherapy in breast cancer patients with non-pCR.
abstract: The research question of this investigation is whether the reduction rate of Ki-67 after neoadjuvant chemotherapy (NAC) could indicate a survival in patients with non-pCR. A total of 455 patients had received NAC, and subsequent surgery was analyzed retrospectively. Patients with non-pCR were divided into three subgroups according to Ki-67 change: High-reduction (the absolute value of Ki-67 was reduced by >80 % compared with that prior to NAC), Low-reduction (the absolute value of Ki-67 was reduced by 0-80 % compared with that prior to NAC), and Increase group (the absolute value of Ki-67 was increased compared with that prior to NAC). The relapse-free survival (RFS) rates were compared among subgroups. pCR was achieved in 93 patients (20.4 %). In patients with non-pCR, the median reduction rate of Ki-67 was 60 %. A total of 15 % of patients were in the High-reduction, 63 % in the Low-reduction, and 22 % in the Increase group. The median follow-up period was 64.5 months. The 5-year RFS rates among the three groups were significantly different (p < 0.0001), and the differences were also observed in the HER2 (p = 0.033), triple-negative (p = 0.034), and luminal-like subtypes (p = 0.001). Patients in the High-reduction group showed comparable RFS to that of patients with pCR (p = 0.363). In patients with non-pCR, the reduction rate of Ki-67 after NAC significantly predicted RFS regardless of cancer subtypes. Therefore, patients who are non-pCR but who achieve a high reduction of Ki-67 can be expected to have a favorable prognosis similar to that of patients with pCR.
authors.affiliation: Department of Breast and Medical Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan, nmatsuba@east.ncc.go.jp.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Matsubara
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Mukai
authors.forename: Mariko
authors.initials: M
authors.lastname: Masumoto
authors.forename: Masaoki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Naito
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujii
authors.forename: Noriaki
authors.initials: N
authors.lastname: Wada
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000378:metabolism*; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000401:mortality*; D009367:Neoplasm Staging; D011379:Prognosis; D012074:Remission Induction; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen