C-ERBB-3 PROTEIN EXPRESSION IN OVARIAN-TUMORS

In this study the expression of c-erbB-3 protein was investigated in a range of human ovarian tumours using a monoclonal antibody (RTJ1) rai sed to a synthetic peptide from the cytoplasmic domain of the human c- erbB-3 protein. A total of 73 samples from 71 patients were graded as negative, weak, moderate or strong according to the intensity of immun ohistochemical staining observed, and this was related to tumour chara cteristics and other clinical parameters. In terms of positivity vs ne gativity, of the 73 samples examined, 62 (85%) showed positive immunoh istochemical staining for c-erbB-3. The majority of all ovarian tumour s studied were positive for c-erbB-3 regardless of whether they were m alignant (89%), borderline (100%) or benign (61%), however the inciden ce of positivity was significantly less in the benign group than in ov ertly malignant tumours (P = 0.03). c-erbB-3 positivity was not signif icantly associated with either age at diagnosis, tumour stage, differe ntiation, ploidy, percentage in 5-phase or post-operative tumour bulk in malignant tumours. In terms of intensity of staining no significant difference was observed either within the common epithelial group or between this group and tumours of a benign nature. A significantly mor e intense pattern of c-eubB-3 staining was observed in tumours of bord erline malignancy when compared with their overtly malignant counterpa rts (P = 0.002). Patients presenting with early-stage malignant tumour s (I/II) were more likely to display intense tumour staining than thos e with late-stage disease (III/IV) (P = 0.04). These investigations su ggest that c-erbB-3 protein is frequently expressed in both benign and malignant ovarian tumours, and that overexpression is more common in borderline and early invasive lesions.