DNA analysis of laryngeal carcinoma cells by flow cytometry: the histoclinical factors and their significance.

In patients suffering from several types of malignant tumours, changes in deoxyribonucleic acid (DNA) content are usually associated with poorer survival prognosis. In the present study, DNA content and clinical and histopathologic features were analyzed in patients suffering from laryngeal carcinoma, with a view to establishing the crucial prognostic factors. In the 5-year follow-up study, flow cytometry was used to analyze DNA content in the paraffin-embedded samples of laryngeal carcinoma tissue obtained from 90 patients who had undergone surgical treatment in the Department of Otolaryngology, Collegium Medicum, Jagiellonian University, Cracow, Poland, in 1987 and 1988. The group consisted of 59 and 31 patients with T3 and T4 tumours, respectively. In each case, neck dissection was carried out either on one or both sides. Metastases in regional lymph nodes were found in 26 patients. The disease-free 5-year survival rate was 55.6%. Among the investigated cases, there were 14 aneuploid and 76 diploid tumours. The treatment yielded the worst results, when the S-phase fraction (SPF) and proliferative index (PI) were equal to or higher than 15.8% and 16.0%, respectively. The values of SPF and PI index did not correlate, however, with the frequency of regional metastases. Univariate analysis revealed that tumour size (T stage), presence of lymph node metastases, age of patients (< or = 60, > 60), tumour differentiation, tumour front grading (<15 points, > or = 15), mode of infiltration, SPF, and PI were positively correlated with the actual survival rate. Presence of lymph node metastases (p = .0001) and the PI (p = .0067) were found to be the only independent prognostic factors when the Cox multivariate analysis was applied. The assessment of the PI by flow cytometry may effectively facilitate the selection of patients recommended for a more aggressive treatment.