Prognostic Value of Flow Cytometric DNA Analysis in Non-Small-Cell Lung Cancer: Rationale of Sequential Processing of Frozen and Paraffin-Embedded Tissue

p = 0.0006). Including subjects submitted to complete tumor removal (stages I, II, and IIIA) in a multivariate analysis adjusted for TNM stage and histologic type, bearers of aneuploid tumors exhibited a higher risk of relapse (hazard ratio 2.65; CI 95% 1.5–4.66; p = 0.004) or death (hazard ratio 2.17; CI 95% 1.08–4.39; p = 0.032) than patients with diploid tumors. DNA ploidy resulted an independent prognostic factor of survival and tumor relapse in completely resected non-small-cell lung cancer. Sequential analysis of fresh and paraffin-embedded samples can help avoid the bias due to intratumoral DNA content heterogeneity. DNA ploidy could be an useful parameter in any future multifactorial analysis of outcome in such tumors.