Early squamous cell carcinoma of the hypopharynx: Outcomes of treatment with radiation alone to the primary disease

Background. This retrospective study analyzes the outcome of treatment of a cohort of patients with hypopharyngeal tumors staged T1 or T2 treated with curative radiation alone to the primary tumor. The potential influence of advances in technology and radiobiology are studied. Methods. Eighty-two patients with early-stage (T1, 19 patients; T2, 63 patients) hypopharyngeal squamous cell carcinomas treated between 1976 and 1992 at the University of Texas M. D. Anderson Cancer Center completed a course of definitive radiotherapy to their primary tumors. Forty-three patients (52%) were node positive, of which 23 (28%) had surgery to their involved necks in addition to radiation. Thirty-six patients (44%) had computerized tomography (CT) as part of the staging workup. Doses to the primary ranged from 60 to 79 Gy. Forty-four patients (54%) in this study were treated with twice-daily radiation (BID). Boosts to gross disease using off spinal cord fields were treated with Co60 gamma rays in 40 patients (49%); 34 (41%) with 6-25 MV x- rays (X), and 8 (10%) with an ipsilateral electron beam field. Results. The 2-year actuarial local control rates for patients with T1 and T2 disease were 89% and 77%, respecitively. Subgroup analysis of T2 patients showed the following differences in actuarial local control rates at 2 years: BID, 86%; no BID, 60% (p, .004%); CT, 83%; no CT, 71% (p, .1); X boost, 88%; no X boost, 67% (p, .04). The actuarial 2- and 5-year survival rates for all patients were 72% and 52%, respectively. Conclusions. A majority of patients with early hypopharyngeal lesions are radiocurable. Patients treated with hyperfractionated radiotherapy and off spinal cord fields with 6 MV (or higher energy) x-ray beams had improved local control rates. CT scans assisted in appropriate patient selection for definitive treatment with radiation.