The use of pelvic radiation in stage II rectal cancer: a population-based analysis

National Institutes of Health (NIH) guidelines recommend the use of pelvic radiation in T3N0 rectal cancer. We sought to determine the rate of compliance with NIH radiation guidelines for patients with T3N0 rectal cancer. We performed a retrospective cohort study of T3NO rectal cancer diagnosed between January 1, 1994, and December 31, 2003, in Region 5 of the California Cancer Registry (R5 CCR). Three hundred twenty-nine patients with T3N0 rectal cancer were identified. The mean age of the study population was 68 years (range, 28 to 93 years). Only 54.1 per cent of patients with T3N0 cancer received pelvic radiation. There was no difference in gender (P = 0.13) or the number of nodes examined (P = 0.19) between patients who had treatment with pelvic radiation and those who did not. However, patients receiving radiation were significantly younger (mean 64 years with radiation therapy [XRT] vs. 72 years without XRT, P < 0.001) and significantly more likely to be treated with systemic chemotherapy (75% with XRT vs. 8.6% without XRT, P < 0.001). Significant numbers of patients with T3N0 rectal cancer are not receiving pelvic radiation in R5 CRR. NIH guidelines are not being translated into clinical practice. The reasons for this warrant continued investigation.