Study on the nodal occult micrometastasis in stage I non-small-cell lung cancer

Abstract

Objective To detect the nodal occult micrometastasis in stage Ⅰ non-small-cell lung cancer(NSCLC),and further investigate the main factor of affecting the nodal occult micrometastasis and the rule of micrometastasis in stage Ⅰ NSCLC. Methods Occult micrometastatic tumor cells by in hilar and subcarinal lymph nodes(LN)were detected immunohistochemistry (SP method),which were removed from 91patients with completely resected stage Ⅰ NSCLC.The monoclonal antibody muhicytokeratin(MCK)was used as a micrometastatic marker.Another 45 hilar LN removed from benign pulmonary lesion patients and 45 hilar LN removed from Ⅱ and Ⅲ stage NSCLC were detected, respectively by conventional histopathologic examination as negative and positive control.Results Micrometastasis was detected in all lymph nodes that were removed from stageⅡand Ⅲ NSCLC.but no one was detected in lymph nodes that were removed from benign pulmonary lesion patients.There were 45 positive cases in 91 patients.The rate of micrometastasis in stage Ⅰ NSCLC was 49%(45/91).among them 39 subcarinal lymph nodes and 11 hilar lymph nodes were detected as positive,5 cases were detected as positive both in subcrinal and hilar lymph nodes.Logistic regression analysis indicated that tumor size,stage and differentiation affected micrometastasis significantly,odd ratios(OR) were 8.444,6.946 and 14.566 respectively.The multivariate analysis indicated that cell difierentiation and T stage may be the adverse factors for nodal micrometastasis,odd ratios(OR)were 7.028and 14.509 respectively.Conclusion There is nodal micrometastasis in completely resected stage Ⅰ NSCLC patients.The micrometastasis frequency of stage ⅠB is significantly higher than stage ⅠA;It is necessary for stage ⅠB NSCLC to be given chemotherapy after operation;cell differentiation and T stage may be the adverse factors for nodal micrometastasis.The method of lymph node micrometastasis is from hilum to mediastinum.The skip micrometastasis may be taken place in adenocarcinoma. Key words: Carcinoma,non-small-cell lung; Lymph nodes; Neoplasm metastasis; Keratins