[Preliminary studies on c-erbB-2 protooncogene in breast cancer]

c-erbB-2 protooncogene amplification was analyzed with Southern blot technique in 50 breast cancer patients in an attempt to correlate the results with the prognosis. The median follow-up was 59 months. Amplification was found in 15/50 (30%) of these patients including two cases of rearrangement. A highly statistically significant difference was found in postoperative survivals of patients with or without c-erbB-2 amplification (P less than 0.005). When patients were divided into groups by stage, nodal status, tumor size and PR status, the prognosis tended to become worse with c-erbB-2 amplification. It was demonstrated that the postoperative median survival of Stage I and II patients with amplification was similar to those of Stage III and IV patients without amplification (48 and 47.8 months). The postoperative median survival of node negative patients with amplification was shortened as compared to those of node positive ones without amplification (47.3 and 54 months). This observation indicates that c-erbB-2 amplification seems to be an useful independent prognosis indicator in breast cancer, particularly in identifying the subsets of high risk of recurrence in node negative or Stage I and II patients.