Cytologic assessment of peroperative pleural effusion and prognosis in lung cancer patients who underwent resection.

Twenty-five of 108 lung cancer patients who underwent resection had cytologically positive pleural effusions. The rate at which cancer cells were detected was not related to the amount of the effusion. Almost one third of patients with cancer cells in effusion were alive at the end of the third postoperative year, provided that the pleura itself was free of metastasis at the time of operation. Correlation of the cytologically positive rate of pleural effusion (Y) with the degree of pleural metastasis (X1), the degree of pleural involvement (X2), or the degree of nodal involvement (X3) was analyzed using the Hayashi's quantification method type I. The multiple correlation coefficient was 0.843. Partial correlation coefficients of X1, X2, and X3 were 0.733, 0.446, and 0.653, respectively. Pleural metastasis had the strongest effect on the cytologically positive rate of pleural effusion.