Prognostic value of residual node involvement in operable breast cancer after induction chemotherapy

The purpose of this retrospective study was to evaluate the influence of axillary disease on patients' survival after neoadjuvant chemotherapy and to assess patient and tumor characteristics associated with post-chemotherapy axillary involvement. After six induction cycles, 277 patients with operable breast cancer (stage II-III) underwent surgery with axillary dissection, followed by radiotherapy (n = 267) or additional chemotherapy (n = 63) and adjuvant tamoxifen therapy (n = 138). At a median follow-up of 8.5 years, overall survival (OS) and disease-free survival (DFS) were analyzed as a function of node involvement. The differences in OS and DFS according to the number of positive nodes were highly statistically significant with a decreased survival associated with the increasing number of nodes (p = 5 x 10(-6) and 9 x 10(-7), respectively). Upon multivariate analysis, the node number after chemotherapy appeared as the most significant prognostic factor (p = 7 x 10(-4) for OS and p = 3 x 10(-5) for DFS). All the other classical prognostic factors were insignificant, except post-chemotherapy Scarff-Bloom-Richardson (SBR) grading for OS (p = 8 x 10(-4)) and adjuvant hormonotherapy for DFS (p = 1 x 10(-2)). Although constituting a different parameter from primary surgery data, the number of positive nodes after chemotherapy could still remain a valuable prognostic factor at secondary surgery, raising the question for high risk patients of a second non-cross-resistant adjuvant regimen, or high dose chemotherapy with peripheral blood stem cells support.