Prognostic significance of parenchymal lymphatic vessel and blood vessel invasion in carcinoma of the lung.

In a series of 685 men who had undergone a microscopically curative resection of a carcinoma of the lung admitted to a prospective randomized adjuvant chemotherapy trial, a review of the data relative to the prognostic implication of either parenchymal lymphatic vessel or blood vessel invasion as determined by routine histologic examination was carried out. In the patients without parenchymal lymphatic vessel invasion and without lymph node metastasis, the three year survival rate was 61.0 per cent. In those without lymphatic vessel invasion but with lymph node metastasis, the three year survival rate was 34.5 per cent. In the patients with lymphatic vessel invasion and no lymph node metastasis, the three year survival rate was 41.7 per cent and when lymph node metastasis was present, it was 33.8 per cent. In the patients without blood vessel invasion and with neither lymph node metastasis nor lymphatic vessel invasion, the survival rate was 61.9 per cent at three years. When either or one, or both, of the latter were present, the survival rate was 35.6 per cent. In the patients with blood vessel invasion, the three year survival rate in those without lymph node invasion or lymphatic vessel invasion was 58.0 per cent, and in those with either one or both, the survival rate was 34.9 per cent. It is concluded that parenchymal lymphatic vessel invasion in itself is an indication of a poor prognosis. However, blood vessel invasion when identified by routine histologic examination was found to provide little, if any, additional predictive information.