Sulfasalazine decreases acute gastrointestinal complications due to pelvic radiotherapy.

Background: Radiation-induced gastrointestinal toxicity is a significant concern for patients who are treated with this modality for pelvic malignancies. Eicosanoids and free radicals are thought to be among the reasons for this effect. Sulfasalazine is an inhibitor of their synthesis in the mucosa. OBJECTlVE: To determine whether sulfasalazine can reduce the radiation-induced acute gastrointestinal complications.

Methods: In this prospective, double-blind study, 31 patients receiving pelvic radiotherapy were randomized to receive two sulfasalazine 500-mg tablets twice daily or placebo, administered orally from the first day of irradiation. Patients were evaluated weekly, and gastrointestinal toxicities were graded according to the Late Effect of Normal Tissue-Subjective Objective Management Analytic (LENT-SOMA) toxicity table during pelvic radiotherapy. On the last day of week 5, the subjects were graded endoscopically, and biopsies taken from the rectum were classified histopathologically.

Results: Groups did not differ in age, gender, tumor site, or irradiation procedure. During radiotherapy, grade 2 or higher gastrointestinal toxicity occurred in 20% (3/15) and 63% (10/16) of the sulfasalazine and placebo groups, respectively. This difference was significant (p = 0.017). No statistically significant differences were found in endoscopic and histopathologic evaluations.

Conclusions: Sulfasalazine is effective in decreasing clinically acute gastrointestinal toxicities. Long-term follow-up with the subjects will help to determine the net effect of sulfasalazine on the radiation-induced gastrointestinal injuries.