Long-Term Analysis and Prospective Validation of A Prognostic Model for Patients with High-Risk Primary Breast Cancer Receiving High-Dose Chemotherapy

Purpose: We described previously a prognostic model for high-risk primary breast cancer patients receiving high-dose chemotherapy (HDC). Such model included nodal ratio (no. involved nodes:no. dissected nodes), tumor size, hormone receptors, and HER2. In the present study we intended to test this model prospectively in a second patient cohort. In addition, we analyzed the long-term overall outcome of our HDC trials. Experimental Design: We analyzed all 264 patients enrolled since 1990 in our prospective trials for 4-9+, ≥10+ nodes, or inflammatory disease. Patients of the second cohort (treated since 1997) had their prognostic score estimated prospectively before receiving HDC. Results: Fourteen patients (5.3%) died from HDC-related complications. At median follow-up of 7.1 years, relapse-free survival and overall survival of the whole group were 69.8% and 73%, respectively. Median time to relapse was 14 months (63.5% relapses within the first 2 years, 6.7% after year 5). The model was validated in the second cohort, establishing the following pretransplant risk categories: low risk (low score, HER2-), 44% patients, 87% freedom from relapse (FFR); intermediate risk (low score, HER2+), 29% patients, 68% FFR; and high risk (high score, any HER2), 27% patients, 49% FFR. Conclusions: Few relapses are seen after year 5 of follow-up, which indicates the need for mature results of the randomized trials before their final interpretation or meta-analysis. Our prospectively validated prognostic model, if additionally confirmed in the randomized trial populations, may provide an insight into the relative benefit of HDC in different risk patient subsets.