Moderate amplifications of the c-myc gene correlate with molecular and clinicopathological parameters in colorectal cancer.

C-myc gene activation is a common event in multiple types of neoplasia and has been associated with different cellular processes relevant to the malignant transformation of cancer cells. C-myc gene amplification has been analysed in colorectal carcinomas by means of an innovative DNA fingerprinting method based on the arbitrarily primed PCR. This method requires a low amount of DNA, uses multiple internal controls and appears sensitive and reproducible. Clinicopathological and molecular correlates have been investigated in a series of 70 colorectal carcinomas. The incidence of c-myc amplification was 26%, ranging from two- to fivefold increase in copy number. C-myc amplification occurrence was more frequent in more advanced stages of tumour invasion (P < 0.001) and was associated with mutations in the p53 tumour-suppressor gene (P = 0.048). The presence of c-myc amplification was indicative of a shorter disease-free survival period but, because of its strong association with Dukes' stage, its prognostic value is questionable.