Carcinoma of the esophagus: pretreatment assessment, correlation of radiation treatment parameters with survival, and identification and management of radiation treatment failure.
Between January 1969 and February 1975, 344 patients with carcinoma of the esophagus were managed primarily at the Princess Margaret Hospital, Toronto. One hundred sixty-eight (168) of the patients were treated palliatively and 176 of the patients were treated by radical doses of radiation, surgical resection or both. Survival of the radical treatment group was biphasic, the steeper component being identical to the survival of the palliative treatment group, thereby representing a group of patients that did not respond to radical treatment. Analysis of pretreatment assessment parameters indicated that all patients with T1 lesions (length less than or equal to 5 cm, circumference incomplete) and all patients with Stage I disease responded to treatment. Patients who were female, age greater than or equal to 70 years, N0 or had well differentiated squamous cell histology, responded to treatment in at least 80% of cases. No patient with extralymphatic distant metastases responded to treatment. The presence of other major disease did not affect response to treatment. Thirty patients had surgical resections and their survival was not significantly greater than the 146 patients who had radical radiation alone. Survival analysis revealed an optimum range of nominal standard dose (NSD) of 1602--1714 rets (median 1679 rets) for patients treated by radiation alone. An optimum port size (area) of 100--140 cm2 was observed for patients receiving 5000 rads and supervoltage irradiation gave a significantly improved survival in comparison with megavoltage irradiation. Sixty-seven percent (67%) of patients treated by radical doses or radiation developed esophageal strictures postradiation and on the basis of radiological, endoscopic or histological evidence 75% of these strictures were considered to be associated with the persistence of malignancy. On the basis of postmortem examinations (32) and death certificates there was overall an 80% failure to control the disease locally and 95% of strictures were associated with persistence of malignancy in the esophagus. Thirty-one of the 146 patients receiving radical radiation alone had palliation for esophageal obstruction following radiotherapy. The construction of a physiological bypass (e.g., colon) resulted in a mean survival of 215 days which was much longer than the survival observed with rigid esophageal tubes (35 days) or gastrostomy tubes (58 days).