MSH6 and Lynch syndrome: 5 The Prospective Lynch Syndrome Database (PLSD) reports that 28.5% of individuals with a diagnosis of MSH2-Lynch syndrome develop urothelial carcinoma during their lifetime, in comparison to 10% and 8% of individuals with a diagnosis of MLH1- and MSH6-Lynch syndrome, respectively5. Upper tract urothelial carcinoma (UTUC), arising in the renal pelvis or ureter, is particularly common in Lynch syndrome with an estimated 14-fold increased risk compared to the general population6. Notably, around 6% of all patients with UTUC have Lynch syndrome.7