COEXPRESSION OF C-ERBB2 AND INT-2 ONCOGENES IN INVASIVE BREAST-CANCER

Invasive breast carcinomas of 19 premenopausal and 49 postmenopausal w omen were studied by Southern blot analysis for detection of c-erbB2 a nd int-2 oncogenes, and quantitation of c-erbB2 protein, p185 by ELISA . The data were correlated with the histological grade of the tumor an d the patient's clinical status. Seventeen tumors (25.0%) showed genom ic alteration in one or both oncogenes. c-erbB2 and int-2 amplificatio n were expressed by 10 (14.7%) and 7 (10.2%) of the tumors respectivel y. c-erbB2 overexpression was found in 15 out of 68 tumors (22.1%). Al l tumors exhibiting amplification of c-erbB2 also showed overexpressio n of p185 protein, however 5 out of 15 tumors (33.3%) showing c-erbB2 overexpression did not show amplification. Rearrangement of c-erbB2 an d int-2 oncogenes was observed in 4 out of 68 tumors (5.9%) and 2 of t hese tumors presented rearrangement of both oncogenes. A significant p ositive correlation was found between c-erbB2 amplification and p185 p rotein overexpression, and c-erbB2 and int-2 amplification. Oncogene a lterations were more frequently detected in tumors with high histologi cal grade, but no correlation was found with patient's age, menopausal or lymph node status.