Surgical Application of DNA Ploidy to Non-small-cell Lung Carcinoma

Clinical application of DNA analysis and a method of rapid DNA measurement were studied. DNA contents of 110 stage I lung carcinomas were measured, using paraffin embedded tissues, by means of flow cytometry. Aneuploidy was fond in 73.6% of the tumors, and diploidy was found in 26.4%. In patients with DNA aneuploidy in T_2N_0, those treated with lobectomy had significantly longer survival time than those treated with limited operations (segmentectomy or partial resection of the lung). These results indicate that patients with DNA aneuploidy among patients with the disease Stage of T_2N_0 should not be treated with limited operations. The DNA content of 44 cases of benign lung diseases were also measured, and none of them were DNA aneuploid cases. It was concluded that DNA aneuploidy was a useful marker of malignant cells. Furthermore, as a surgical application of these results, interoperative DNA analysis is necessary ; so that a method of rapid DNA analysis was invented. It was possible to achieve DNA measurement within 15 minutes by using Triton X-100, RNase and PI, and the best DNA histogram was acquired by using 5% Triton X-100, 20 Kunitz/ml RNase and 50 μg/ml PI. These results indicate that it is possible to make interoperative DNA analysis and also it is useful to detect malignant cells and to determine the operative procedure