Prognostic significance of DNA ploidy in squamous cell lung carcinoma: is it really worth it?

Background. Many previous studies attempted to associate DNA quantification with prognosis for lung cancer, but there is a divergence of opinion about its value. The purpose of the study was to evaluate the frequency of abnormal DNA content in squamous cell cancer (SCC) and analyze its correlation with late survival rates after surgical treatment. Methods. A group of 110 patients surgically treated because of SCC was analyzed. Paraffin-embedded pathologic material underwent cytometric analysis. Postoperative follow-up was performed with standard follow-up visits. The statistical analysis was carried out using Mann-Whitney’s U and χ2 tests to compare various variables in both groups. The survival curves were drawn using the Kaplan-Meier method. Clinical staging, regional metastasis, and ploidy, were analyzed with multivariate analysis for having a great impact on survival rates. Results. Fifty (45%) tumors were DNA aneuploid. The survival rate in patients with aneuploid cancers was worse than in those with diploid tumors and the most frequent cause of death was local recurrence (p< 0.05). Conclusions. DNA content abnormalities were found to be an important prognostic factor in patients with SCC. The DNA quantification can select a group of high risk of recurrence even after a radical procedure and set new guidelines for adjuvant therapy.