THE RELATION OF RADIOSENSITIVITY OF HYPOPHARYNGEAL SQUAMOUS-CELL CARCINOMA TO DNA-PLOIDY

Purpose: The purpose of this study was to examine the radiosensitivity of T1, N0, M0 squamous cell carcinomas of the hypopharynx treated sol ely with external beam radiation, Materials and Methods: Nuclear DNA c ontent and cell cycle kinetics of 29 archival paraffin-embedded specim ens suitable for interpretation were analyzed with an ELITE flow cytom eter (Coulter Diagnostics, Opa Locka, FL). Results: In the radiosensit ive group with no evidence of disease for 36 months, 86% of the tumors were diploid and 14% were aneuploid, The mean DNA index for this grou p was 1.02. In the radioresistant group, with recurrence within 36 mon ths, 80% of the tumors were aneuploid, and 20% were diploid, The mean DNA index for this group was 1.32. Conclusions: The findings could hav e clinical significance because if aneuploidy occurs in an early hypop haryngeal squamous cell carcinoma, the clinician might select surgical resection over radiation therapy.