S-phase fractions and DNA-ploidy of oropharyngeal squamous epithelium carcinomas compared with histologic grade, stage, response to chemotherapy and survival.

DNA-ploidy and the percentage of S-phase fractions in 55 primary oropharyngeal squamous epithelium carcinomas were measured by DNA-Flow Cytometry (FCM). The data were compared with the histologic grade, the stage and the response of the tumours to cytostatic chemotherapy. A significant correlation was found between the histologic grade and the mean percentage of S-phase fractions (p less than 0.01). No correlation could be found between the FCM measurement data and the tumour stage. Carcinomas with an amount from 4.0 to 10.4% S-phase fractions responded to chemotherapy by complete remission, and those with 10.0 to 13.3% S-phase fractions by partial remission. The group of non-responders could be subdivided into two subgroups: non-responders with low amounts of S-phase fractions (1.1-3.9%), and non-responders with very high amounts of S-phase fractions (11.6-16.6%). FCM data, histologic and clinical prognostic factors were summed up to a prognostic score. The number of score points showed a significant correlation to the length of survival in months after diagnosis of the tumour (p less than 0.00001). FCM may be used as an additional diagnostic tool for a better biological characterization of the neoplastic tissue, especially as an aid for grading, prediction of the response to chemotherapy and the length of survival.