Immunohistochemical detection of mutant p53 protein in regional lymph nodes is associated with adverse outcome in Stage II Colorectal Cancer

Epidemiologic data identifies a cohort of Duke's B (CRC) patients whose sur vival more closely matches that of Duke's C. Lymph node micrometastases may account for this discrepancy. Lymph node expression of mutant p53 protein (Mp53P) has been linked to a reduction in survival in Japanese Duke's B pat ients. We aimed to determine the significance of nodal p53 expression in European Duke's B patients using immunohistochemistry. The study comprised 134 consecutive patients who had resections for CRC bet ween 1984 and 1991. End points were 5 year disease free survival or CRC rel ated death. Thirty-four subjects did not achieve end points and were exclud ed. We examined tumour and nodal sections for Mp53P by immunohistochemistry and correlated this with survival using a Kaplan-Meier (KM) and a Cox Prop ortional hazards model (CPHT). Five year survival was 73%. Fifty-eight percent of primary tumours expresse d Mp53P. Tumour p53 expression did modulate survival behavior. Twenty-six p ercent of subjects' lymph nodes expressed Mp53P Fifty-three per cent of tho se with positive and 17% of those with negative lymph nodes died of recurre nce. The relative risk for nodal Mp53P expression was 3.1. There was a sign ificant univariate relationship between lymph node p53 expression and morta lity. (Log Rank p=0.028). Multivariate analysis also showed a significant r elationship with mortality. (CPHT p=.03). We conclude that lymph node expression of Mp53P is associated with increase d mortality in Duke's B CRC.