Immunohistochemical analysis of nm23-H1 in stage I non-small cell lung cancer: A useful marker in prediction of metastases

Background. About 30% to 40% of patients with pathologic stage I non-small cell lung cancer die within 5 years after complete resection. The identification of subgroups with high risk of recurrence is important. The level of nm23-H1/nucleoside diphosphate kinase expression has been reported to correlate inversely with the metastatic potential of some tumors. Methods. We examined immunohistochemically the expression of nm23-H1 in 32 stage I non-small cell lung cancers to determine its value in predicting the outcome of the operation. Results. Twelve (37.5%) recurrences and ten deaths occurred in this series. There were eight (25%) distant and four (12.5%) locoregional recurrences. Of the 32 pathologic stage I non-small cell lung cancers, 10 (31.3%) were positive for nm23-H1 gene product. None of the patients with a higher nm23-H1 protein level had detectable distant metastases at the end of this study (χ² test, p < 0.05). The median follow-up time to date is only 35 months (range, 18 to 83 months), and so far no significant difference in overall survival rate has been observed between the groups with high and low nm23-H1 protein levels. Conclusions. The level of nm23-H1 protein is more useful than the T status or histologic type for the prediction of distant metastases, whereby cases may be selected for postoperative adjuvant chemotherapy.