Radiation therapy in patients with inflammatory bowel disease and colorectal cancer: risks and benefits.

PURPOSE

The effects of radiotherapy are debated in inflammatory bowel disease (IBD). We examined IBD patients with colorectal cancer (CRC) and compared those who underwent external beam radiation therapy (EBRT) to those who did not. We then compared those same patients treated with EBRT to similarly treated non-IBD patients to ascertain differences in toxicity and perioperative outcomes.

METHODS

Fifty-seven IBD patients with CRC received EBRT, of which 23 had perioperative follow-up and 15 had complete records. The 23 patients were compared to 229 IBD patients with CRC who did not receive EBRT. The 15 patients were matched, 1:2, to similarly treated non-IBD patients with CRC based on age (±5 years), treatment year (±1 year), BMI (±10 kg/m2), and clinical stage.

RESULTS

There was significantly more postoperative bleeding (5.3 % vs. 0 %, p < 0.01), wound dehiscence (3.5 % vs. 0 %, p < 0.01), and perineal infection (8.8 % vs. 1.3 %, p < 0.01) in IBD patients with EBRT compared to those without EBRT. IBD patients were significantly more likely to have grade 3 or higher lower GI toxicity (40 % vs. 7 %, p = 0.02) and wound dehiscence (36 % vs. 7 %, p = 0.02) than non-IBD patients, however without significant difference in bleeding, infection, ileus, or survival.

CONCLUSION

IBD patients with CRC who received EBRT were more likely than similar patients without EBRT to experience perioperative complications. These patients also experienced more lower GI toxicity than similarly treated non-IBD patients with CRC. The expected decrease in survival in IBD-associated CRC was not observed. Thus, EBRT may contribute to a survival benefit in this group.