Objective: Acute proctitis and chronic radiation proctitis are relevant complications of pelvic radiation. The purpose of this study was to investigate two markers of gut inflammation during and after irradiation for prostate cancer to evaluate a correlation between acute and chronic proctitis.
Material and methods: Two patient groups were analysed. In group 1, stool samples from 20 patients were collected before therapy, every week during therapy, at the end of therapy, and 13 and 27 months after therapy. Group 2 comprised 47 patients who had undergone irradiation 40 months earlier. Toxicity was determined by common toxicity criteria (CTC) and the LENT soma scale. Calprotectin and lactoferrin values were determined by ELISA.
Results: In group 1, acute values for both faecal markers were significantly correlated with chronic proctitis symptoms and all patients with chronic toxicity had acute proctitis symptoms with elevated faecal values. In group 2, where stool samples were solely collected 40 months after irradiation, the Pearson square test showed both a significant correlation between calprotectin and lactoferrin values and toxicity after 40 months.
Conclusions: Within a group of 19 patients followed for two years after irradiation for prostate cancer, and 47 patients tested 40 months after irradiation, increased faecal values of calprotectin and lactoferrin were significantly correlated with the occurrence of chronic proctitis. This observation should be confirmed in an expanded study.