Microsatellite instability as indicator of MSH2 gene mutation in patients with upper urinary tract transitional cell carcinoma

Upper urinary tract transitional cell carcinoma (UUTTCC) accounts for 5% of all urothelial carcinomas.1 Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant syndrome predisposing to colorectal cancer that accounts for about 5% of all colorectal cancers.2 It is revealed by colorectal cancer (63%) or extracolonic cancers, most often of the endometrium (9%) or ovary, but sometimes of the upper urinary tract (5%), small bowel, stomach, or hepatobiliary tract.3–5 Patients with hereditary non-polyposis colorectal cancer have a genetic risk of developing these cancers.3,6 This study concerns patients with upper urinary tract transitional cell carcinoma who did not meet the international clinical criteria (Amsterdam criteria)5 for hereditary non-polyposis colorectal cancer. The question that arises is whether the biochemical and molecular biology tests used to screen for hereditary non-polyposis colorectal cancer might not help detect hereditary disease among these cases of upper urinary tract transitional cell carcinoma.7 The tests used in suspected cases of hereditary non-polyposis colorectal cancer are: