Lymph node status in different molecular subtype of breast cancer: triple negative tumours are more likely lymph node negative.

Background and Objectives: To investigate the association between different molecular subtype (MST) and the axillary lymph nodal (ALN) status. Materials and Methods: A total of 528 female patients with primary breast cancer were collected. Survival estimates were calculated using the Kaplan-Meier method, univariate and multivariate logistic regression models. Results: Triple negative and Luminal A breast cancers were more frequently node-negative (N0) when compared to Luminal B and Her-2 positive cancers (77.4% and 73.4% vs. 45.3% and 40.0%, respectively; P < 0.0001). We observed a clearly significant difference among ALN status in patients with Her-2 positive (P = 0.001) and Luminal B (P < 0.0001) breast cancer. While no significant prognostic diffreence among different LN status was detected in the Triple negative (P = 0.070) and Luminal A subtype (P = 0.660). On the other hand, we detected no prognostic diffreence among different MST in N1 and N3 subgroups (P = 0.569 and P = 0.484, respectively). Multivariate analysis showed that lymph node status (P < 0.01), molecular subtype (P < 0.01), and tumor size (P < 0.01) were significantly and independently prognostic factors. The c-index of the prognosis nomogram for recurrence prediction was 0.70. Conclusion: Triple negative breast cancer is not associated more frequently with a higher number of involved nodes. The prognosis nomogram can predict the probability of recurrence patients within 3 or 5 years.