NM23 gene product expression does not predict lymph node metastases or survival in young patients with colorectal cancer.

NM23 gene product is a putative metastases suppressor gene which has structural homology to a nucleoside diphosphate kinase. Previous studies examining the relationship between NM23 gene product expression and survival in patients with colorectal cancer have revealed conflicting results. However, no study has focused on young patients with colorectal cancer. This study was carried out to determine if expression of the NM23 gene product was correlated with metastatic potential and survival in young patients (45 years and under) with colorectal cancer. Eighty- one patients with colorectal cancer were studied and the presence of the NM23 gene product (H1) was detected using standard immunohistochemical techniques. NM23 gene product expression did not correlate with tumour stage, lymph node involvement by tumour, presence of distant metastases, extramural vascular invasion or degree of tumour differentiation. Independent risk factors for overall survival were: Dukes' stage (p=0.00001) and extramural vascular invasion (p=0.003). NM23 expression was not an independent prognostic indicator (p=0.55). Therefore, NM23 expression does not correlate with existing indicators of tumour aggressiveness and behaviour nor is it an independent predictor of survival in young patients with colorectal cancer.