[Studies on flow cytometric analysis of nuclear DNA content in non-small cell lung cancer]

To evaluate the relationship between DNA ploidy and the clinical stage of the disease or the prognosis, tumor DNA content was determined by flow cytometry in paraffin-embedded specimens obtained surgically from the patients with primary lung cancer. A good correlation in DNA indices between fresh and paraffin-embedded specimens was observed (r = 0.978), although one tumor with DNA near-diploidy was mistaken as DNA diploid in paraffin-embedded specimens. DNA content analysis was carried out for 171 of 178 patients (401 of 427 paraffin-embedded specimens). Of the 171 patients, 155 could be enrolled in the clinical and pathological study, and 118 in the prognostic study. One hundred and nineteen (76.8%) patients had DNA aneuploid patterns that were higher in adenocarcinoma than in squamous cell carcinoma (p less than 0.05) Although the proportion of DNA aneuploidy was not associated with the pathologic stage, a better 5-year survival rate was observed in Group A (DNA diploidy, 62.9%) than in Group B (DNA aneuploidy and DNA peridiploidy, 28.4%; p less than 0.001). Therefore, the DNA content was considered to be an independent prognostic factor for survival in patients with non-small cell lung cancer. To evaluate the relationship of DNA content with histopathologic heterogeneity, the morphologic study was carried out on hematoxylin and eosin stained sections in adenocarcinoma of the lung. Seventeen patients had DNA multiploidy and 10 of 17 tumors with DNA multiploidy showed prominent pleomorphism in histologic morphology. DNA content seemed to be related to histopathologic differences in non-small cell lung cancer. The measurement of DNA content is useful for evaluation of clinical behavior and prognosis of the patients with non-small cell lung cancer.