Prognostic significance of postoperative empyema in lung cancer.

Four hundred sixty patients who had undergone resection for lung cancer, with a minimum follow-up of 10 years, were analyzed retrospectively. Thirty-eight cases developed postoperative empyema. A comparative evaluation of the long-term survival rate was made of two groups: one in which the patients had developed empyema and one in which the patients had developed no empyema complications. The survival rate was estimated by the Kaplan Meyer Product Limit Method. The prognostic significance of empyema and other factors was analyzed by the Log Rank Test, the chi 2 test in homogeneous series of patients and the Cox Hazard Model. Overall, the ten-year survival rate was 23.7% in the empyema group and 15.9% in the control group. After stratification by post-surgical stage, lymphocytic infiltration of primary-tumor (LI), and histological type, no significant differences in survival between the two groups were demonstrated by the Log Rank Test. The same results were found when the survival distribution of the empyema cases was compared with two control groups of patients without empyema, individually paired to the empyema group for Immune Response (LI), post-surgical stage, and histological type. In the end, after multivariate analysis empyema was not shown to be a factor of prognostic significance.