Most peripheral, node-negative, non-small-cell lung cancers have low proliferative rates and no intratumoral and peritumoral blood and lymphatic vessel invasion

Abstract

We investigated the tumor aggressiveness (intratumoral and peritumoral lymphatic and blood vessel invasion by tumor emboli) and proliferative activity (mitotic count) of 45 patients with peripheral, superficially seated, node-negative (T1-2 N0 M0), non-small-cell lung cancer treated with wedge resection alone between January 1982 and June 1988. Most patients were male (n = 39) with T1 (n = 25), small (mean diameter, 2.6 +/- 0.8 cm), squamous (n = 24), right-sided (n = 29) tumors located in either upper lobe (n = 35). The surgical specimens were studied by immunohistochemical staining with a monoclonal antibody targeting the factor VIII-related antigen. None of the tumors had lymphatic peritumoral or intratumoral invasion. Seven neoplasms (15%) harbored blood vessel invasion by tumor cells; all but one of these invasions were within the substance of the tumor. The median mitotic count was 8 mitoses per 10 high-power fields (range, 1 to 42 mitoses), significantly (p = 0.003) higher in patients with blood vessel invasion than in those without. With a 24-month minimum follow-up, projected 3- and 5-year survivals are 79% and 68%, respectively. Eleven patients had relapses and died of their tumors because of either local (n = 5) or extrathoracic (n = 6) recurrence; three patients died without tumors of comorbidity. Among the six tumors recurring in extrathoracic sites, five (83%) harbored intratumoral (n = 4) or peritumoral (n = 1) blood vessel invasion. Both recurrence of disease and death from non-small-cell lung cancer were significantly (p = 0.0009) higher for tumors with blood vessel invasion. By univariate analysis, significant predictors of survival were tumor stage (T1 vs T2, p = 0.008), size (< or = 2.6 cm vs > 2.6 cm, p = 0.039), mitotic count (< or = 8 vs > 8 mitoses, p = 0.0007), and blood vessel invasion (absence vs presence, p = 0.0001). By multivariate analysis, however, only blood vessel invasion retained its level of prognostic significance (p = 0.006). Data demonstrate that peripheral, node-negative non-small-cell lung cancers have a low metastatic potential. Whenever anatomically feasible, wedge resection seems to be an appropriate method of primary treatment.