Aim of study: To identify whether nodal ratio (NR) of positive to excised nodes is superior to number of positive lymph nodes to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive, T1-T2 breast cancer patients.
Materials and methods: Postmenopausal estrogen receptor (ER)-positive, lymph node-positive patients who received endocrine therapy (n = 173) with complete baseline data in our hospital between 2000 and 2006 were included. The disease-free survival (DFS) was compared. Survival analysis was performed using Kaplan-Meier method. Cox proportional hazard models were used to evaluate the prognostic value of chemotherapy with different NR for DFS. P--values less than 0.05 were regarded as significant.
Results: The median follow-up was 72 months. Three of 13 variables analyzed remained significantly prognostic for survival in the Cox proportional hazards model. These included age (hazard ratio (HR) =1.642, 95% confidence interval (CI) =1.154-2.337, P = 0.006); histological grade (HR = 2.463,95% CI = 1.389-4.367, P = 0.002); and NR (HR = 2.280, 95% CI = 1.113-4.671, P = 0.024). Subgroup analysis by NR status showed that in patients with NR ≥ 0.20, chemotherapy significantly improves DFS (HR = 0.360, 95% CI = 0.195-0.663, P = 0.001); while in patients with NR < 0.20, chemotherapy did not significantly affect DFS (HR = 0.677, 95% CI = 0.227-2.107, P = 0.493). Radiotherapy is an important factor that improves DFS in lymph node-positive patients, so it is considered in all analysis.
Conclusion: This retrospective analysis demonstrates that NR of positive to excised nodes, but not number of positive lymph nodes is better to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive T1-T2 breast cancer patients.