NM-23 H1 IMMUNOHISTOCHEMISTRY IS NOT USEFUL AS PREDICTOR OF METASTATIC POTENTIAL OF COLORECTAL-CANCER

This study aimed to investigate whether immunohistochemical staining f or nm23-H1 protein in the primary tumour is correlated with tumour sta ge, tumour differentiation, DNA ploidy, cell proliferative index, p53 status and patient survival time in colorectal cancer. Full-cross colo rectal cancer biopsies were collected from 202 consecutive surgical sp ecimens between 1987 and 1990. Immunohistochemical expression of nm23- H1 protein was investigated in cryosections, using a monoclonal anti-n m23-H1 antibody (clone NM 301). The staining pattern was classified as follows: strong homogeneous intensity, moderate homogeneous intensity , moderate focal intensity, or as negative. Immunohistochemical expres sion of p53 was investigated using a monoclonal anti-p53 antibody (DO- 7). The DNA ploidy and cell proliferative index were determined by dow cytometry. Possible correlation between nm23-H1 staining patterns and the other studied tumour characteristics was explored at the end of 1 994. Median survival time of living patients was 66 months, range 50-9 3 months. No correlation was found between various nm23-H1 staining pa tterns and tumour stage, cell proliferative index or p53 status. Nm23- H1-negative tumours and tumours with moderate focal staining intensity were less differentiated than tumours with strong homogeneous or mode rate homogeneous staining intensity (P<0.05). Of the nm23-H1-negative tumours, a significantly higher number was near-diploid rather than an euploid, as compared with those expressing positive nm23-H1 (P<0.05). The number of dead patients in Dukes' stages B and C did not correlate significantly with the nm23-H1 staining pattern. The nm23-H1 staining pattern alone, or combined with either of the other explored tumour c haracteristics, did not correlate with patient survival time. Immunohi stochemical studies of the nm23-H1 protein expression are of minor val ue in the staging and prognostic prediction of colorectal cancer.