C-MYC AND RAS-P-21 ONCOGENE EXPRESSION IN GALLBLADDER CARCINOMA

The expression of c-myc and p-ras-21 oncogenes was studied using an im munohistochemical method with monoclonal antibodies in 126 samples of gallbladder carcinoma (103 primary tumors and 23 metastatic lesions). Twenty five gallbladder samples without tumor evidence were used as co ntrols. C-myc oncoprotein was positive in one control sample and p-ras -21 oncoprotein was negative in all. Among primary carcinomas c-myc wa s positive in 9 (9%) and p-ras-21 in 4 (4%); among metastatic carcinom as c-myc was positive in 6 (26%, p = 0,03 vs primary carcinoma) and p- ras-21 in 11 (48%, p < 0.001 vs primary carcinoma). There was a non si gnificant association between c-myc and p -ras-21 expression and degre e of histological differentiation and level of tumoral infiltration. I t is concluded that c-myc and p-ras-21 oncoprotein expression is obser ved in less than 10% of primary gallbladder carcinomas and that this e xpression is significantly higher in metastatic carcinomas. This may r eflect an activation or overexpression of these oncogenes in metastati c cells.