Late gastrointestinal morbidity in patients with stage I-II testicular seminoma treated with radiotherapy

Objectives: To define the incidence and risk factors for late gastrointestinal (GI) morbidity in patients with testicular seminoma treated with radiotherapy (RT). Methods and materials: A retrospective review was conducted of 251 patients with stage I or II testicular seminoma treated with curative-intent RT at our institution from 1974 to 2009. All patients underwent orchiectomy and postoperative external beam RT to the involved nodal basin or at-risk nodal basin or both. Potential late GI morbidities that were assessed included endoscopically confirmed peptic ulcer disease (PUD), small bowel obstruction (SBO), and biopsy-confirmed malignancy of the GI tract. The probabilities of these GI morbidities were estimated with the Kaplan-Meier method. Univariate analyses were performed to examine for associated predictive factors using the Cox proportional hazards model. Results: Median age at diagnosis was 36 years (range 18-80). Clinical stage was I (n = 199) or II (n = 52). Median abdominopelvic RT dose was 26. Gy (interquartile range = 25-30). Median follow-up was 15 years (range = 0.1-38). PUD risk at 10, 20, and 30 years was 4%, 7%, and 9%, respectively. Age at diagnosis (per y, HR = 1.05, 95% CI 1.00-1.09, P = 0.04) and RT dose (per Gy, HR = 1.20, 95% CI 1.09-1.31, P<0.01) were associated with risk of PUD. SBO risk at 10, 20, and 30 years was 2%, 2%, and 3%, respectively. History of inflammatory bowel disease was associated with risk of SBO (HR = 43, 95% CI 7-325, P<0.01). GI second malignancy risk at 10, 20, and 30 years was 0.5%, 3% and 16%, respectively. Age at RT was associated with risk of GI malignancy (per y, HR = 1.07, 95% CI 1.02-1.14, P = 0.01). Conclusions: In this patient population, late GI morbidity was relatively uncommon, but clinically significant. Refinements of treatment strategies may reduce this risk.