No nodal cutoff in node-positive breast cancer women treated with mastectomy

To search for a prognostic cutoff in the number of involved axillary lymph-nodes, in T1-T2 node-positive (N+) breast cancer treated with mastectomy without radiotherapy.

Women aged 51-64 years presenting with a first primary T1-T2, N+, M0 unilateral carcinoma diagnosed in 1988-97 were selected from the SEER 9-registries. Cutoffs from 1 to 23 nodes were scanned with Cox models that included diagnostic year, age, area, race, marital status, histology, grade, hormone receptors, tumor location, size, and nodes examined. Outcomes were breast cancer specific and any-cause death.

The overall mortality hazard ratio of a higher number of involved nodes as compared with a lower number ranged from 1.78 [95% confidence 1.58-1.99] with 1-node cutoff, to 3.65 [2.52-5.29] with 23-nodes cutoff. Breast cancer specific mortality hazard ratio ranged from 1.99 [1.73-2.29] with 1-node cutoff, to 4.63 [3.11-6.91] with 23-nodes cutoff. The graph of the hazard ratios showed a continuously increasing risk of overall and breast cancer specific mortality, without any identifiable cutpoint change.

The results show no prognostic cutoff in the number of involved axillary lymph nodes in patients who did not receive radiotherapy. The rationale of nodal cutoff as an indicator for post-mastectomy adjuvant treatment in node-positive patients should be questioned.