Adjuvant Radiation for Rectal Cancer: Do We Measure Up to the Standard of Care? An Epidemiologic Analysis of Trends Over 25 Years in the United States N. N. Baxter, M.D., Ph.D., 1 D. A. Rothenberger, M.D., 1 A. M. Morris, M.D., M.P.H., 2 K. M. Bullard, M.D. 1 1 Division of Colon and Rectal Surgery, Department of Surgery, University of Minnesota, Minneapolis, Minnesota 2 Division of Colon and Rectal Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan PURPOSE: In the United States, adjuvant radiation therapy is currently recommended for most patients with rectal can- cer. We conducted this population-based study to evaluate the rate of radiation therapy and the factors affecting its delivery. METHODS: We used the Surveillance Epidemiol- ogy and End Results database to assess treatment of patients with nonmetastatic rectal cancer diagnosed over a 25-year period (1976 through 2000). We evaluated the rate of ra- diation therapy use and its timing (preoperative vs. postop- erative) and the influence of factors such as tumor stage and grade; patient gender and race; and geographic location. RESULTS: In this 25-year period, 45,627 patients met our selection criteria. The rate of radiation therapy use in- creased dramatically over time: from 17 percent of ad- vanced-stage patients in 1976 to 65 percent in 2000 (P < 0.0001). Until 1996, the increase was due almost entirely to postoperative radiation therapy. Since 1996, the rate of pre- operative radiation therapy use has increased (P < 0.0001) and the rate of postoperative radiation therapy use has be- gun to decline. We found, after controlling for the year of diagnosis, that female patients, African Americans, older pa- tients, and patients with low-grade lesions were less likely to undergo radiation therapy (P < 0.0001). Geographic lo- cation was also an important predictor of radiation therapy use. CONCLUSIONS: The use of radiation therapy for pa- tients with rectal cancer has dramatically increased over the 25-year period studied, with a recent shift to the use of preoperative radiation therapy; however, in 2000, over 30 percent of patients with advanced-stage nonmetastatic rec- tal cancer did not undergo radiation therapy. Given the variation in radiation therapy use that we found to be due to demographic factors, access to adjuvant radiation therapy can be improved. [Key words: Rectal cancer; Adjuvant ra- diation; Patterns of care; Staging; Preoperative radiation] R ectal cancer, a common cancer, is associated with significant morbidity and mortality. In 2004, almost 41,000 Americans will develop rectal cancer. 1 The traditional treatment of this disease has relied on radical resection. Unfortunately, in the past, such pa- tients experienced significant rates of local recur- rence. Reported rates of local recurrence were as high as 30 percent, 2 with a median local recurrence rate of 18.5 percent. 3 Local recurrence is a multifactorial problem and is affected by tumor, patient, and treat- Supported in part by the University of Minnesota Cancer Center. Read at the meeting of The American Society of Colon and Rectal Surgeons, Dallas, Texas, May 8 to 13, 2004. Reprints are not available. Correspondence to: N. N. Baxter, M.D., Ph.D., Division of Sur- gical Oncology, Department of Surgery, University of Minnesota, 420 Delaware Street SE, MMC 450, Minneapolis, Minnesota 55455, e-mail: baxte025@umn.edu Dis Colon Rectum 2005; 48: 9–15 DOI: 10.1007/s10350-004-0792-8 © The American Society of Colon and Rectal Surgeons Published online: 7 December 2004 9