The detection of the c-myc and ras oncogenes in nasopharyngeal carcinoma by immunohistochemistry.

Forty-one paraffin embedded specimens of primary nasopharyngeal carcinoma (NPC) were examined to investigate the expression of c-myc and ras oncogenes. Sections were stained with the monoclonal antibodies myc 1-9E10 or ras Y13-259 and binding was detected using the ABC method. The intensity of staining for each tumour was assessed as nil, moderate or intense. The results indicated that 9 (22%) had intense staining for the c-myc oncogene, 28 (68%) had moderate staining and only 4 (10%) showed no staining. For the ras oncogene, 8 (19%) had intense staining, 22 (54%) moderate staining and 11 (27%) showed no staining. The patient's clinical data indicated no correlation between the expression of either c-myc or ras p21 and age, sex, smoking, tumour stage, antibody titre to EBV, or family history. No correlation was found between ras p21 expression and survival; however, overexpression of the c-myc oncogene correlated with a poor prognosis (p < 0.05). This study is consistent with investigations demonstrating that c-myc expression correlates with poor survival in head and neck tumours.