Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: In his Editorial accompanying our study,1 Dr Church2 suggests that “[t]he very low SIR at 10 years must be artifactual because cancer rates eventually should converge.” We are unaware of evidence that would support the assertion that colorectal cancer (CRC) rates in a low-risk population should converge with CRC rates in the general population. We believe that a high-quality negative colonoscopy result identifies individuals who are at low risk of developing CRC. Our findings suggest that this group continues to have a decreased risk of developing CRC even beyond 10 years following performance of their initial negative colonoscopy result and are supported by another recent study.3
Singh H, Turner D, Xue L, Targownik LE, Bernstein CN. Colonoscopic Screening for Colorectal Cancer. JAMA. 2006;296(20):2438-2439. doi:10.1001/jama.296.20.2438-a