Prognostic importance of the axillary lymph node ratio in autologous transplantation for high-risk stage II/III breast cancer

The role of autologous peripheral blood progenitor cell (PBPC) transplantat ion for high-risk stage II/III breast cancer remains controversial. New pro gnostic indicators defining subsets of patients who may benefit from autolo gous PBPC transplantation would be clinically useful. The axillary lymph no de ratio, defined by the total number of axillary nodes involved with cance r divided by the number of axillary nodes surgically sampled, has been repo rted to be of potential prognostic importance in transplantation for high-r isk, stage II/III breast cancer. We therefore retrospectively reviewed 111 women with high-risk, stage II/III breast cancer with at least four positiv e axillary lymph nodes undergoing autologous PBPC transplantation from 1991 to June 1999. None of the patients had received prior radiotherapy and all had completed one, and only one, course of at least three cycles of adjuva nt chemotherapy. The median number of axillary nodes sampled was 20 (range 6-40) and the median number of positive axillary nodes was 12 (range 4-35). The median node ratio, dividing the number of positive nodes by the number of sampled nodes, was 0.68. Event-free survival was strongly influenced by node ratio. Patients having a node ratio of <0.7 had a 5-year event-free s urvival of 68%, vs those with a node ratio of <greater than or equal to>0.7 with a 5-year event-free survival of 46% (P = 0.03). Forty percent of pati ents with a high node ratio have relapsed vs 20% with a low node ratio (P = 0.02). Multivariate analysis revealed that positive estrogen receptor stat us and a node ratio of <0.7 were independent factors related to better even t-free survival (P = 0.0001 and P = 0.004, respectively). We conclude that patients having a node ratio of <0.7 have a significantly better prognosis following autologous PBPC transplantation than do patients with a ratio gre ater than or equal to0.7.