ABSTRACT

This study aimed to evaluate the association of axillary lymph node ratio (LNR) and number of positive lymph nodes (pN) with the risk of breast cancer recurrence and death.

A retrospective cohort study of node-positive stage II and III breast cancer patients diagnosed and treated between 2008 and 2009 at the Brazilian National Cancer Institute (INCA), Brazil. Overall and disease-free survival curves for number of positive lymph nodes (pN) and lymph node ratio (LNR) risk groups were constructed using the Kaplan-Meier method and compared by the log-rank test. Multivariate analysis was performed using stepwise forward Cox regression models.

In total, 628 women with node-positive breast cancer were included. Most patients (69.5%) had advanced clinical stage tumors (≥IIB). The median follow-up was 58 months (range: 3‒92 months). The adjusted recurrence hazard of pN2 and pN3 patients was 2.47 (95% Confidence Interval [CI] 1.72-3.56) and 2.42 (1.62-3.60), respectively, compared to pN1 patients (p<0.001), while the hazard of intermediate (0.21‒0.65) and high-risk (>0.65) LNR was 2.11 (1.49-3.00) and 3.19 (2.12-4.80), respectively, compared to low-risk LNR (≤0.20) patients (p<0.001). On the other hand, the hazard of death of pN2 and pN3 patients was 2.17 (1.42-3.30) and 2.41 (1.53-3.78), respectively (p<0.001), and the hazard of intermediate (0.21‒0.65) and high-risk (>0.65) LNR patients was 1.70 (1.13-2.56) and 2.74 (1.75-4.28), respectively (p≤0.001).

Higher pN and LNR were associated with shorter disease-free survival and overall survival times.