Intensity-Modulated vs. Conventional Radiation Therapy for Anal Cancer
Posted: Wednesday, December 12, 2018
For patients with locally advanced anal squamous cell carcinoma, intensity-modulated radiation therapy (IMRT) may support uninterrupted treatment regiments and reduce the need for ostomy. Proposed as an alternative to conventional therapy, IMRT appeared to offer both short- and long-term benefits in a study of nearly 800 patients from a national Veterans Affairs database, which was published in the International Journal of Radiation Oncology • Biology • Physics.
“We were surprised that IMRT allowed more patients to complete a full course of chemotherapy,” revealed study author Alex K. Bryant, BS, of the University of California, San Diego, School of Medicine in an American Society for Radiation Oncology press release. “We were encouraged that IMRT allowed more patients to undergo this potentially life-saving treatment.” James D. Murphy, MD, also of the University of California, San Diego, was the senior study author.
Based on data from a national Veterans Affairs database, the retrospective analysis included 779 patients diagnosed with locally advanced anal cancer between 2000 and 2015. Of them, 403 underwent conventional radiation therapy and 376 underwent IMRT.
Compared with patients who were treated with conventional therapy, those treated with IMRT achieved better short- and long-term outcomes: not only did more patients complete their second cycle of chemotherapy (92% vs, 79%), but these patients were also less likely to undergo radiation treatment breaks for periods longer than 5 days. Additionally, there was a 40% reduced hazard of tumor-related ostomy placement for patients treated with IMRT rather than conventional therapy.
However, no significant differences were noted in acute hematologic toxicity, gastrointestinal toxicity, and cancer-specific survival rates between the two treatment groups. The link between completion of chemotherapy and improvement in toxicities/overall survival requires further investigation, according to the investigators.