In 1964 the Veterans Administration Surgical Adjuvant Group (VASAG) initiated a large-scale, controlled, randomized protocol to study the role of low-dose preoperative irradiation (2000-2500 rads/10fractions/12 days) in patients with operable adenocarcinoma of the sigmoid colon and rectum. This report analyzes the data in 700 patients, all at 5-year risk. There appears to be a definate benefit to irradiated patients who undergo abdominoperineal resections, when compared with the controls. This advantage is reflected in improvement of 5-year survival, and reduction in lymph node invasion, local recurrence, and distant metastases. A second protocol has been initiated in 30 VA hospitals employing a higher dose (3150 rads) to extended portals (toL2) to male patients who require abdominoperineal resections.

No abstract

In a prospective randomized trial, 700 patients with a confirmed histological diagnosis of adenocarcinoma of the rectum or rectosigmoid were randomized to receive radiotherapy prior to operation (2000 to 2500 rads in two weeks) or surgery alone. Five year observed survival in the 453 patients on whom "curative" resection was possible was 48.5% in the X-ray treated group compared with 38.8% in controls, while in the 305 having low lying lesions requiring abdominoperineal resection, survival in the treated group was 46.9% compared with 34.3% in controls. Although suggestive of a treatment benefit, neither is considered statistically significant. Histologically positive lymph nodes were found in 41.2% of the control group and in only 27.8% of the patients receiving radiotherapy. Reveiw of all patients who died during the study shows a consistently lower death rate from cancer in the radiotherapy group. Although this study suggests a treatment benefit from preoperative radiotherapy, further studies now in progress by this group and others are necessary to determine the optimal dose regimen.