title: Overexpression of the c-myc proto-oncogene in colorectal carcinoma is associated with a reduced mortality that is abrogated by point mutation of the p53 tumor suppressor gene.
abstract: The survival of 119 colorectal cancer patients was analyzed in the light of the overexpression status of the c-myc proto-oncogene mRNA and the point mutation status of the p53 tumor suppressor gene in the primary adenocarcinoma. The presence of >3 fold overexpression of c-myc mRNA in the primary tumor was found to be associated with a better prognosis than patients who evinced no overexpression (P = 0.02, log rank analysis). Point mutation of the p53 tumor suppressor gene was found to be associated with a poorer patient prognosis (P = 0.007, log rank analysis). Endogenous levels of c-myc and point mutation of p53 both contributed independently toward a poorer patient prognosis in Cox regression modeling. The better prognosis seen in patients who overexpress c-myc was offset when c-myc overexpression was coupled with a point mutated p53 gene. These results suggest that in colorectal adenocarcinoma c-myc deregulation leads to increased apoptotic death, but that this response may be modulated by a more downstream event such as point mutation of the p53 gene.
authors.affiliation: Colorectal Cancer Research Laboratory, Department of Colorectal Surgery, Singapore General Hospital, Outram Road, Singapore 169608, Republic of Singapore.
authors.forename: D R
authors.initials: DR
authors.lastname: Smith
authors.forename: H S
authors.initials: HS
authors.lastname: Goh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality; D005260:Female; D016259:Genes, myc; D016158:Genes, p53; D006801:Humans; D008297:Male; D008875:Middle Aged; D017354:Point Mutation; D000090063:Proto-Oncogene Mas; D015996:Survival Rate