EVALUATION AND TREATMENT OF PATIENTS RECEIVING RADIATION FOR CANCER OF THE RECTUM OR SIGMOID COLON IN THE UNITED-STATES - RESULTS OF THE 1988-1989 PATTERNS OF CARE STUDY PROCESS SURVEY

Purpose: For the first time, a Patterns of Care Study (PCS) was conducted in 1989 to determine the national practice standards of radiation oncologists in evaluating and treating adenocarcinoma of the rectum and sigmoid colon. Materials and Methods: A national survey of 73 institutions using two-stage cluster sampling was conducted, and specific information on 408 patients from 69 facilities with adenocarcinoma of the rectum and sigmoid colon who received radiation as part of definitive or adjuvant management was collected. Results: Using the modified Astler-Coller (MAC) pathologic staging system, the stage distribution was as follows: A, 0.5%; B1, 4.4%; B2, 23.5%; B3, 5.1%; C1, 8.9%; C2, 30.2%; and C3, 6.6%. Preoperative radiation was used in 29% of patients, but the total dose was greater than 40 Gy in only 20%. Seventy-three percent of patients received postoperative radiation, with approximately 4% receiving combined preoperative and postoperative radiation. Chemotherapy was administered to 44% of patients overall, representing 55% of patients with disease through the bowel wall and/or involving lymph nodes. Only 37% of all patients received chemotherapy concurrent with radiation. An abdominoperineal resection was used in 43%; a low anterior resection was used in 43% as well, while 5% underwent other types of bowel resection. Approximately 8% of patients were treated with a local curative procedure less than bowel resection (eg, local excision, endoscopic resection, fulguration, or contact radiation). At least one third of patients had interruption in their pelvic irradiation of greater than 3 days. There was no statistically significant difference in the frequency of treatment interruptions by dose per fraction or whether chemotherapy was given concurrent with radiation. There was no significant difference in total dose delivered to patients staged B2 and higher treated without chemotherapy compared with concurrent chemotherapy and radiation. Also, there was no significant difference in total dose delivered to patients with B1 and B2, or C1 and C2 versus B3 or C3 cancer. Conclusion: This study was conducted on patients treated just before the 1990 National Institutes of Health consensus guidelines issued on the management of colon and rectal cancer. This study indicates that the minority of patients treated with radiation in 1988 and 1989 received concurrent chemoradiation, as currently recommended. Additionally, insofar as present studies are investigating important issues such as the use of sphincter-sparing procedures, preoperative radiation and chemotherapy, and the importance of radiation dose and scheduling with chemotherapy, the information provided by this study will serve as a useful baseline to track future changes in rectal cancer evaluation and management.