title: Small node-negative (T1b-cN0) invasive hormone receptor-positive breast cancers: is there a subpopulation that might have benefit from adjuvant chemotherapy?
abstract: The aims of the study were to identify a subpopulation more likely to be at greater risk of recurrence in small T1b-c node-negative hormone receptor (HR)-positive breast cancer, and which would benefit from adjuvant chemotherapy. Clinico-pathologic characteristics and clinical outcomes of 538 postoperative HR-positive T1b-cN0 breast cancer patients were retrospectively analyzed. High Ki67 index and a young age (< 35 years) were identified as independent risk factors for relapse (p < 0.0001 and 0.015, respectively). A nomogram based on Cox-regression model showed an area under the curve (AUC) of 0.73 in the training set. The validation set showed a good discrimination with an AUC of 0.65. In patients with high nomogram scores (≥ 100, n = 24, 4.5%) who had high Ki67 index with more than 75%, or young age (< 35 years) and a Ki67 index > 50%, the relapse-free survival curve of patients who had received anthracycline-containing adjuvant chemotherapy showed a better outcome than those who had not (p = 0.029). Ki67 index and age are valuable surrogate markers to predict recurrence and as indicators of tumors that could benefit from adjuvant chemotherapy in small T1b-c node-negative HR-positive breast cancer.
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul 135-710, Korea.
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Park
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.forename: Eun Yoon
authors.initials: EY
authors.lastname: Cho
authors.forename: Yoon-La
authors.initials: YL
authors.lastname: Choi
authors.forename: Jeong Eon
authors.initials: JE
authors.lastname: Lee
authors.forename: Seok Jin
authors.initials: SJ
authors.lastname: Nam
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Yang
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Ahn
authors.forename: Young-Hyuck
authors.initials: YH
authors.lastname: Im
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D009367:Neoplasm Staging; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D049451:Nomograms; D016016:Proportional Hazards Models; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult