P53 AND C-ERBB-2 AS MARKERS OF RESISTANCE TO ADJUVANT CHEMOTHERAPY INBREAST-CANCER

Recent literature suggests that c-erbB-2 and p53 alteration might be l inked to drug resistance. This study investigates the relation of c-er bB-2 oncoprotein overexpression and p53 protein accumulation with prog nosis in patients with node-positive breast cancer (NPBC) and assesses the modifying effect of these markers on response to short (1-10 cour ses) or prolonged (> 10 courses) adjuvant chemotherapy, This study is based on 458 patients with NPBC diagnosed from 1980 to 1986, with an a verage of 10 years of follow-up. Marker expression was evaluated by im munohistochemical analysis on formalin-fixed, paraffin-embedded materi al with antibodies to c-erbB-2 and p53. c-erbB-2 was expressed in 17.2 % of the cases, and 19.1% of the tumors stained positively for p53, By multivariate analysis, women with prolonged adjuvant chemotherapy had better survival than those with a short course of chemotherapy among patients whose tumor lacked c-erhB-2 oncoprotein expression (P =.0245) or p53 protein accumulation (P =.0477), Prolonged chemotherapy, howev er, was associated with little or no change in survival among patients whose tumor expressed those markers. The present study adds support t o the hypothesis linking c-erbB-2 and p53 expression to drug resistanc e.