Abstract
BACKGROUND: The prevalence and associated psychosocial morbidity of late-onset anorectal disease after surgery and radiotherapy for the treatment of childhood cancer are not known. METHODS: A total of 25,530 survivors diagnosed between 1970 and 1999 (median age at cancer diagnosis, 6.1 years; age at survey, 30.2 years) and 5036 siblings were evaluated for late-onset anorectal disease, which was defined as a self-reported fistula-in-ano, self-reported anorectal stricture, or pathology- or medical record-confirmed anorectal subsequent malignant neoplasm (SMN) 5 or more years after the primary cancer diagnosis. Piecewise exponential models compared the survivors and siblings and examined associations between cancer treatments and late-onset anorectal disease. Multiple logistic regression with generalized estimating equations was used to evaluate associations between late-onset anorectal disease and emotional distress, as defined by the Brief Symptom Inventory 18 (BSI-18), and health-related quality of life, as defined by the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). RESULTS: By 45 years after the diagnosis, 394 survivors (fistula, n = 291; stricture, n = 116; anorectal SMN, n = 26) and 84 siblings (fistula, n = 73; stricture, n = 23; anorectal neoplasm, n = 1) had developed late-onset anorectal disease (adjusted rate ratio [RR] for survivors vs siblings, 1.2; 95% confidence interval [CI], 1.0-1.5). Among survivors, pelvic radiotherapy with ≥30 Gy within 5 years of the cancer diagnosis was associated with late-onset anorectal disease (adjusted RR for 30-49.9 Gy vs none, 1.6; 95% CI, 1.1-2.3; adjusted RR for ≥50 Gy vs none, 5.4; 95% CI, 3.1-9.2). Late-onset anorectal disease was associated with psychosocial impairment in all BSI-18 and SF-36 domains. CONCLUSIONS: Late-onset anorectal disease was more common among childhood cancer survivors who received higher doses of pelvic radiotherapy and was associated with substantial psychosocial morbidity.