HER2 NEU OVEREXPRESSION IS ASSOCIATED WITH TREATMENT FAILURE IN WOMENWITH HIGH-RISK STAGE-II AND STAGE IIIA BREAST-CANCER (GREATER-THAN-10INVOLVED LYMPH-NODES) TREATED WITH HIGH-DOSE CHEMOTHERAPY AND AUTOLOGOUS HEMATOPOIETIC PROGENITOR-CELL SUPPORT FOLLOWING STANDARD-DOSE ADJUVANT CHEMOTHERAPY/

Twenty-five patients with high-risk stage II and IIIA breast cancer (> 10 or more involved lymph nodes) were treated with six cycles of stand ard-dose chemotherapy (5-fluorouracil, doxorubicin, and cyclophosphami de) followed by high-dose chemotherapy (2.5 g/m(2) cyclophosphamide fo r 3 days and 225 mg/m(2) thiotepa for 3 days) with autologous hematopo ietic progenitor cell support. The actuarial relapse free survival at 3 years is 80%; the actuarial survival at 3 years is 96%. Four patient s relapsed systemically between 6 and 18 months; all four patients who relapsed had breast cancers that overexpressed Her2/neu. In contrast, none of the 21 patients who had no or borderline overexpression of He r2/neu relapsed (P = 0.00004, Fisher's exact test). Patients with high -risk stage II and IIIA breast cancer who have overexpression of Her2/ neu appear to be at a high risk for relapse, even when treated with hi gh-dose chemotherapy and autologous hematopoietic progenitor cell supp ort.