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 solely with external beam radiation. Materials and Methods: Nuclear DNA content and cell cycle kinetics of 29 archival paraffin-embedded specimens suitable for interpretation were analyzed with an ELITE flow cytometer (Coulter Diagnostics, Opa Locka, FL). Results: In the radiosensitive 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 group was 1.02. In the radioresistant group, with recurrence within 36 months, 80% of the tumors were aneuploid, and 20% were diploid. The mean DNA index for this group was 1.32. Conclusions: The findings could have clinical significance because if aneuploidy occurs in an early hypopharyngeal squamous cell carcinoma, the clinician might select surgical resection over radiation therapy.