The
DNA ploidy of fresh frozen tissues from
head and neck squamous cell carcinomas was determined by flow cytometry, with the aim of investigating whether
DNA ploidy correlates with various clinical and pathological parameters. The subjects were 51 patients who had undergone radical surgery in our department. The
DNA ploidy pattern was classified into three types, diploid, single
aneuploid and multiploid, according to the
DNA index and the
DNA histogram. This is our original classification. No particular correlation could be detected between the
DNA ploidy pattern and sex, age, primary
tumor site or disease stage. The degree of tissue differentiation tended to be poorer in
aneuploid than in diploid tissues. The efficacy of
chemotherapy was higher in
aneuploid than in diploid cases. The recurrence rate was significantly lower in diploid than in multiploid cases. When disease stage, degree of histological differentiation, the efficacy of
chemotherapy and the
DNA ploidy pattern were subjected to multivariate analysis for correlation with prognosis, the
DNA ploidy pattern showed the highest correlation. Our results suggest that the
DNA ploidy, as analyzed by flow cytometry, can serve as useful prognostic factor.