Open and shut case.

Could radiation exacerbate a malignant fistula from anorectal cancer? This is an important question, as such concerns could prevent patients from benefiting from definitive or palliative radiation. In this retrospective study of 639 patients with anorectal cancer, 7.4% had a malignant fistula prior to treatment. After treatment, over half (59%) experienced improvement in their fistula, including 31% that had complete resolution. The median time to response was 50 days. Important to note is that all the patients with persistent fistula had persistent local disease after radiation. In other words, malignant fistulae from anorectal cancer are more likely to resolve with disease response, and pelvic radiation appears to help rather than hinder this process. | Koroulakis, Pract Radiat Oncol 2022