ABSTRACT
<p><b>OBJECTIVE</b>To analyze the relationship between DNA content and biological behavior and its prognostic significance in non-small cell lung cancer.</p><p><b>METHODS</b>Tumor DNA content was determined by flow cytometry in the specimens from 58 patients with resected non-small cell lung cancer. The DNA content of each cell subpopulation was expressed as the DNA index (DI), and an internal standard was provided by the normal pulmonary parenchymal cells in the same specimen. The prognostic value of DNA content in non-small cell lung cancer was assessed by Cox's model analysis.</p><p><b>RESULTS</b>In qualitative analysis, there was no relationship between DNA ploidy (diploidy or aneuploidy) and the following factors: tumor size, metastasis of lymph node, clinical stage, pathologic type, pathologic grade or survival. In quantitative analysis, high DNA index was observed in tumor size > 3 cm, metastasis of lymph node, stage III/IV, adenocarcinoma and shorter survival, which was statistically significant. Cox's model analysis showed that DNA index was a prognostic factor in non-small cell lung cancer and DNA index > 2.0 was an independent prognostic factor.</p><p><b>CONCLUSION</b>DNA index analysis is useful for the evaluation of the biological behavior and the prognosis of non-small cell lung cancer.</p>