Overexpression of c-erbB-2 protein and locoregional recurrence in node-positive breast cancer

The expression of c-erbB-2 protein was analysed in tumour specimens from 49 node-positive breast cancer patients with locoregional recurrence and 147 matched control patients without such events. The level of c-erbB-2 expression was quantified together with DNA content by flow cytometry. Odds ratios were calculated by matched logistic regression analysis. Nearly half of the tumours in the recurrence group (45%) showed elevated levels of c-erbB-2 compared to 25% of those in the control group. The odds ratio comparing patients with and without locoregional relapse increased significantly with increasing levels of c-erbB-2 expression. c-erbB-2 expression was a statistically significant indicator in addition to the number of lymph node metastases. Tumour size, hormone receptor status and S-phase fraction, which are known indicators of distant recurrence, were not independently associated with locoregional relapse. S-phase fraction, but not cerbB-2 overexpression, correlated with survival following locoregional recurrence.