The relevance of flow-cytometric DNA content in the evaluation of lung cancer

Cells from a group of 185 patients suffering from malignant tumours (160 non-small-cell lung carcinoma, 13 small-cell lung carcinoma, and 12 non-epithelial tumours) and 6 with benign lung tumours were studied by flow cytometry in order to detect the prognostic value of DNA content. A total of 144 (90%) non-small-cell lung carcinomas (NSCLC) and 8 (62%) small-cell lung carcinomas (SCLC) exhibited aneuploidy. Furthermore 52% (83 patients) NSCLC, 24% (3 patients) SCLC and 50% (6 patients) non-epithelial tumours demonstrated multiclonality. Benign cases showed diploid DNA content. For actuarial survival analysis using the Bergesson and Gage method and the Greenwood variance, 142 patients were selected. Statistical comparisons were made by the use of the t-test for unpaired data between fixed times. No correlation was observed between ploidy and stage, histological grading or treatment modality. A statistically significantly better survival was observed after 12, 18 and 24 months of follow-up for diploid and monoclonal (with the exclusion of hypo- and hypertetraploid) patients. Thus, flow-cytometric DNA analysis may be useful in prognostic assessment of human lung tumours.