Prospective screening for Lynch syndrome (LS) in a cohort of colorectal cancer (CRC) surgical patients in a community hospital.

Abstract

1535 Background: LS is the most common hereditary form of colon cancer yet it is under-diagnosed despite well-defined clinical criteria. Screening an incident U.S. population of patients with CRC placed the proportion of CRC due to LS at 2.8% (Hampel H et al, N Engl J Med 352: 1851, 2005 and J Clin Oncol 26: 5783, 2008). Immunohistochemistry (IHC) stains for the 4 mismatch repair (MMR) proteins have shown a high sensitivity for LS identification (Shia J, J Mol Diagnostics 10: 293, 2008). We hypothesized that if only CRC patients ≤ age 60 were screened for LS by IHC, only 25% of patients would undergo testing yet 75-80% of LS would be identified. Summarized here are the results of the first 24 months of the IHC screening program for LS in a community hospital. Methods: In January 2008 a pathology reflex protocol for MMR IHC staining was initiated on all CRC ≤ age 60. The protocol was reviewed and approved by the institution's clinical practice committees. Results: From 1/01/08 through 12/31/09, 302 surgica...