Development and validation of a scoring system for late anorectal side-effects in patients treated with radiotherapy for prostate cancer

Abstract

PurposeTo develop and validate a scoring system for evaluation of long term anorectal dysfunction following radiotherapy for prostate cancer. Materials and methodsPatients treated for prostate cancer with radiotherapy filled in questionnaires on anorectal function and quality of life. Items for the condensed anorectal dysfunction score (RT-ARD) were identified and weighted by binomial regression analysis. The score was tested in a separate patient material by receiver operating characteristic (ROC) analysis and correlations to quality of life domains. ResultsA total of 309 patients participated in the study. The items selected were “incontinence for solid stool”, “ability to defer defecation”, “unproductive call to stool”, “clustering of stool”, and “mucus in stool.” Patients were grouped into three categories according to the RT-ARD score; 0–8 (no RT-ARD), 9–23 (minor RT-ARD), 24–45 (major RT-ARD). ROC analyses revealed high sensitivity (91%) and specificity (85%) for major RT-ARD. The prediction model demonstrated a perfect fit in 60%, moderate fit in 36% and no fit in 4%. There was good correlation between the RT-ARD score and quality of life. ConclusionsThe RT-ARD score is a validated and simple instrument for evaluation of anorectal dysfunction following radiotherapy for prostate cancer, and the RT-ARD score correlates to the patient’s quality of life.