Breast Cancer Subtypes and Survival in Chinese Women with Operable Primary Breast Cancer

Objective: To investigate the associations between the different breast cancer subtypes and survival in Chinese women with operable primary breast cancer. Methods: A total of 1538 Chinese women with operable primary breast cancer were analyzed in this study, the median follow-up was 77 months. Estrogen receptor (ER), progesterone receptor (PR), and HER2 status were available for these patients. Results: Luminal A (ER+ and/or PR+, HER2-) had a favorable disease-free survival (DFS) and overall survival (OS) compared with other subtypes in the entire cohort. Using the luminal A as a reference, among the patients with lymph node positive disease, HER2+ (ER-, PR-, HER2+) had the worst DFS (hazard ratio, HR=1.80, 95% CI 1.11 to 2.91, P=0.017) and luminal B (ER+ and/or PR+, HER2+) had the worst OS (HR=2.27, 95% CI 1.50 to 3.45, P<0.001); among the patients with lymph node negative disease, triple-negative (ER-, PR-, HER2-) had the worst DFS (HR=2.21, 95% CI 1.43 to 3.41, P<0.001), whereas no significant difference in DFS between HER2+ and luminal B or luminal A was observed. Conclusion: As compared with luminal A, luminal B and HER2+ have the worst survival in patients with lymph node positive disease, but this is not the case in patients with lymph node negative disease; triple-negative subtype has a worse survival in both lymph node positive and lymph node negative patients.