NM23-H1 IMMUNOSTAINING IS INVERSELY ASSOCIATED WITH TUMOR STAGING BUTNOT OVERALL SURVIVAL OR DISEASE RECURRENCE IN COLORECTAL CARCINOMAS

The NM23-H1 gene product has been recently identified as a potential m etastasis suppressor. Studies on breast carcinomas have shown an inver se correlation between NM23-H1 status and stage of carcinogenesis and overall survival. However, in colorectal cancer, conflicting data have been reported. This study aimed to investigate whether NM23-H1 immuno staining is correlated with tumour stage, overall survival, disease re currence, tumour differentiation, age and sex in colorectal carcinomas for the Singapore population using chi-square analysis. The staining was performed on 141 paraffin-embedded surgical specimens collected be tween 1991 and 1992 using a monoclonal anti-NM23-H1 antibody. Follow-u p of patients was until time of death or for 5 years. There was a very significant inverse association between tumour staging and NM23-H1 st atus (P = 0.0004). However, NM23-H1 expression was not significantly c orrelated to overall 5-year survival, disease recurrence, tumour diffe rentiation, age or sex. Thus, although NM23-H1 may be involved in supp ressing metastasis, NM23-H1 immunohistochemistry has no prognostic val ue in colorectal cancer, This is the first report of a significant inv erse association of NM23-H1 status with tumour staging in colorectal c ancer which showed no correlation with overall survival or disease rec urrence. Our result thus cautions against the practice of equating an inverse relation of genetic markers with tumour staging to survival or disease recurrence.