BACKGROUNDTo evaluate the biological significance of the lymphnode micrometastasis in non-small-cell lung cancer (NSCLC).

METHODSNinety regional lymph nodes indicated to be tumor free by conventional histopathologic methods were taken from 39 patients who underwent pulmonary resection for NSCLC. CK immunohistochemical staining was used to detect the micrometastatic tumor cells in lymph nodes. Expressions of p53, p21(ras) and Ki67 in primary pulmonary lesions were also detected by immunochemical methods.

RESULTSMicrometastasis were found in 26 lymph nodes (28.89%) of 22 patients (56.4%). The proportion of patients with micrometastasis whose primary lesions had the expressions of p53, p21(ras) and Ki67 was higher than those without micrometastasis whose primary lesions had no expressions of p53, p21(ras) and Ki67. The proportion of patients with micrometastasis whose tumor size was more than and less than 3 cm was 55.6% and 58.3% respectively (P=1.000).

CONCLUSIONSExpressions of p53, p21(ras) and Ki67 in primary pulmonary lesions has certain relations with micrometastasis in lymph nodes.