Risk of Gastric and Small Intestinal Cancer in Patients With Lynch Syndrome: Data From a Large, Community-Based US Population.

Introduction: Risk of gastric and small intestinal cancer in Lynch syndrome (LS) remains poorly understood. We investigated the risk of gastric and small intestinal cancer in patients with LS in a large, community-based population.

Methods: This retrospective cohort study included all patients diagnosed with LS between January 1, 1997, and December 31, 2020, at Kaiser Permanente Northern California.

Efficacy of paired tumor and germline testing in evaluation of patients with Lynch-like syndrome in a large integrated healthcare setting.

Patients with mismatch repair (MMR) deficient colorectal cancer (CRC) without detectable germline pathogenic variants (PVs) or likely pathogenic variants (LPVs) in MMR genes are often labeled as Lynch-like syndrome (LLS). We sought to evaluate the efficacy of paired tumor and germline testing in risk stratification of patients with LLS in a large, community-based, integrated healthcare setting. Through the universal screening program for Lynch syndrome at Kaiser Permanente Northern California, we identified all patients with MMR deficient colorectal tumors without detectable germline PVs or LPVs between April 2011 and October 2018.