Radiation therapy of esophageal cancer

Abstract

Radiation therapy has been used extensively in the management of patients with cancer of the esophagus. It has demonstrated an ability to cure a small minority of patients. Cure is likely to be limited to patients who have lesions less than 5 cm in length and have minimal, if any, involvement of lymph nodes. Esophagectomy is likely to cure a similar, small percentage of patients with the same presentation of minimal disease but has a substantial acute postoperative mortality rate and greater morbidity than irradiation. Combining surgery and either preoperative or postoperative irradiation may cure a small percentage of patients beyond the number cured with either modality alone. Radiation has demonstrated benefit as an adjuvant to surgery following the resection of minimal disease. However, radiation alone has never been compared directly with surgery for the highly select, minimal lesions managed by surgery. Radiation provides good palliation of dysphagia in the majority of patients, and roughly one third may have adequate swallowing for the duration of their illness when "radical" doses have been employed. Surgical bypass procedures have greater acute morbidity but appear to provide more reliable, prolonged palliation of dysphagia. They constitute the best approach for patients with persistent or recurrent dysphagia following esophageal irradiation. Several approaches to improving the efficacy of irradiation are currently under investigation. Fewer large fractions appear to be equivalent to conventionally fractionated radiotherapy in terms of local control and survival but produce more prompt palliation and shorten courses of palliative therapy. Multiple-daily-fractionation schedules and hyperfractionation have theoretical appeal and clear basis for investigation from the early suggestions of improved response rates in advanced squamous-cell cancer of the head and neck. Hypoxic-cell radiosensitizers, neutron-beam, and helium-ion therapy results have not been overly encouraging in esophageal cancer, thus far. However, the new generation of particle beams and the new radiation-sensitizer drugs require further evaluation. Better means of dealing with the high incidence of disseminated disease are clearly needed. It is clear that combined-modality approaches using both local and systemic therapy will ultimately be desireable in esophageal-cancer treatment. Whether surgery, irradiation, or both will constitute the best local therapy for patients receiving chemotherapy is unclear. Of those options, irradiation offers substantially less acute morbidity and mortality than surgery or combined radiation and surgery. Recent experience with combined-modality therapy at Wayne State University indicates synergistic effects of combination chemotherapy and irradiation in apparently localized disease.58 Thirty-nine percent of patients had no evidence of tumor in resected specimens following two cycles of mitomycin C, 5-fluorouracil, and 3000 rad. Local recurrence decreased to 13% following chemotherapy and 5000 rad. This encouraging early experience suggests that effective systemic therapy and local irradiation may soon surpass the results of local measures alone and may eliminate the early acute morbidity and mortality inherent in esophageal resection. © 1984.