Radiation Therapy Changed the Second Malignancy Pattern in Rectal Cancer Survivors

Background and Objectives: Radiotherapy (RT) plays an important role in the treatment for locally advanced rectal cancer patients. It can bring radio exposure together with survival benefit. Cancer survivors are generally at increased risk second malignancies, receiving RT may have higher risks than not RT. Whether of all-site malignancy increase after is still debated. This study aims to compare pattern Materials Methods: The Surveillance, Epidemiology, End Results (SEER) database was used analysis. In total, 49,961 patients (20–84 years age) were identified between 2000 2012 from 18 SEER registries. All underwent surgery. occurrence malignancies diagnosed diagnosis compared who received did receive standardized incidence ratios (SIRs) 95% confidence intervals (CIs) used. SEER*Stat generate CIs SIR statistics using exact method. Results: Of total patients, 5582 developed malignancies. For primary age-adjusted SIRs 1.14 (95% CI 1.1–1.18) 1.00 0.96–1.04) no groups, respectively. 23,192 surgery-only group, 2604 had 26,769 RT, 2978 With respect every site, secondary prostate significantly lower group (SIR = 0.39, 0.33–0.46) that 1.04, 0.96–1.12). Moreover, thyroid 2.80, 2.2–3.51) 1.29, 0.99–1.66). Conclusions: change survivors; decreased, most significantly.