Adult ; Age Factors ; Aged ; Aged, 80 and over ; Antineoplastic Agents ; therapeutic use ; Carcinoma ; epidemiology ; pathology ; radiotherapy ; Disease-Free Survival ; Female ; Humans ; Hypopharyngeal Neoplasms ; epidemiology ; pathology ; radiotherapy ; Hypopharynx ; surgery ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Neoplasm Staging ; Prognosis ; Proportional Hazards Models ; Radiotherapy, Adjuvant ; Radiotherapy, Intensity-Modulated ; Retrospective Studies ; Sex Factors ; Smoking ; epidemiology ; Tumor Burden

INTRODUCTIONOur study investigates whether an approximation of breast cancer molecular subtypes using the hormone receptors and HER-2 status prognosticates for disease control after breast conservation therapy (BCT) in node-negative Asian breast cancer patients.

METHODS AND MATERIALSWe retrospectively reviewed 541 women with node-negative breast cancers treated with BCT between 1989 and 2007. Hormone receptors and HER-2 status were obtained from patients' histological report. All patients received radiotherapy. Thirty-six percent and 68% of women received chemotherapy and hormonal treatment respectively.

RESULTSMedian follow-up of patients is 72 months. Five-year local recurrence free survival (LRFS) is 97.2% for the cohort but differs between subtypes: luminal A, 0.8%; luminal B, 1.4%; HER-2, 3.6% and basal-like, 12.7% (P = 0.047). The 5-year distant disease free survival (DDFS) is 96.4% for the cohort but differs between subtypes: luminal A, 98.2%; luminal B, 92.6%; HER-2, 89.5% and basal-like, 91.5% (P = 0.019). The 5-year disease free survival (DFS) is 94.4% for the cohort but differs between subtypes: luminal A, 97.4%; luminal B, 92.7%; HER-2, 86.3% and basal-like, 85.0% (P = 0.007). Univariate analysis with luminal A as baseline revealed an association of the other 3 subtypes with decreased DFS (P = 0.007), Hazard Ratio (HR) of 2.2, 4.4 and 3.3 to Luminal B, HER-2 and basal subtypes, respectively. On multivariate analysis, HER-2 subtype (AHR = 3.3, 95% CI, 1.1 to 9.8, P = 0.036) and basal-like subtype (HR = 3.5, 95% CI, 1.2 to 9.9, P = 0.019) prognosticate adversely for DFS.

CONCLUSIONThe combination of hormone receptors and HER-2 status can be used as surrogates for molecular subtypes in Asian breast cancer patients with node-negative disease to prognosticate LRFS, DFS and DDFS.

Adult ; Aged ; Aged, 80 and over ; Breast Neoplasms ; genetics ; pathology ; prevention & control ; Female ; Humans ; Mastectomy, Segmental ; Middle Aged ; Multivariate Analysis ; Neoplasm Recurrence, Local ; Prognosis ; Radiotherapy, Adjuvant ; Receptor, ErbB-2 ; genetics ; Receptors, Estrogen ; genetics ; Receptors, Progesterone ; genetics ; Retrospective Studies ; Risk Assessment ; Survival Analysis ; Treatment Outcome