BLOOD AND LYMPHATIC VESSEL INVASION AS PROGNOSTIC FACTORS FOR PATIENTS WITH PRIMARY RESECTED NONSMALL CELL-CARCINOMA OF THE LUNG WITH INTRAPULMONARY METASTASES

Background. The new classification of intrapulmonary metastases of lun g cancer was proposed by the American Joint Committee on Cancer; howev er, the prognostic factors are heterogeneous and not yet fully clarifi ed. In this study, the authors evaluated the prognostic factors for an d the possible routes of intrapulmonary metastases. Methods. The facto rs influencing the prognosis of primary resected nonsmall cell lung ca rcinomas with intrapulmonary metastasis in the resected specimens were evaluated according to the Cox proportional hazards model using a tot al of 66 nonsmall cell lung carcinomas. The possible routes of tumor s pread via the blood or lymphatic vessels also were evaluated. Results. The overall 5-year survival rate was 26.1%, and the statistical analy sis of survival curves revealed a significant difference with regard t o N classification (P = 0.042), site of intrapulmonary metastasis (P = 0.012), blood vessel invasion (P = 0.0046), and lymphatic vessel inva sion (P = 0.0267); there were no significant differences in relation t o age, sex, histology, differentiation, T classification, tumor size, stage, number of intrapulmonary metastases, or size of intrapulmonary metastasis. Multivariate analysis according to the Cox proportional ha zards model identified a significant correlation between survival and blood vessel invasion (P = 0.044) and lymphatic vessel invasion (P = 0 .042), suggesting independent prognostic significance. The correlation between site of intrapulmonary metastasis and the ratio of blood or l ymphatic vessel invasion showed a significantly lower ratio of blood v essel invasion in cases with intrapulmonary metastases at sites centra l to the primary lesion or in different segment(s) compared with those in cases with intrapulmonary metastases at sites peripheral to the pr imary lesion or in ipsilateral different lobe(s), suggesting a possibl e lymphatic vessel route of tumor spread. Conclusion. Blood vessel and lymphatic vessel invasion are important clinical factors in evaluatin g prognosis and the route of tumor spread in primary resected nonsmall cell carcinoma with intrapulmonary metastasis.