RAS AND C-MYC PROTEIN EXPRESSION IN COLORECTAL-CARCINOMA - STUDY OF CANCER-PRONE PATIENTS

This study was performed to determine the correlation of tumor ras and c-myc oncogene expression with clinical and prognostic variables in patients prone to develop colorectal cancer. One hundred eighteen patients with colorectal cancer were studied; mean age was 40 years. Fifty-three were young patients (age 40 or less), 49 had ulcerative colitis, and 16 had multiple polyposis coli. Immunoperoxidase stains of paraffin-embedded cancer sections were performed for the c-myc and ras proteins. ras staining was found to correlate with Dukes stage and prognosis. Patients with tumors negative for ras protein stain had an actuarial five-year survival of 61 percent versus 44 percent for those tumors with a positive stain (P < 0.05). This correlation was not seen with the c-myc stain. Positive ras oncogene stain appears to bc a useful indicator of advanced stage and poor prognosis in colorectal cancer occurring in cancer-prone patients.