- The modified clinical Bethesda criteria for hereditary nonpolyposis colorectal cancer (HNPCC), which are as follows: individuals with 2 HNPCC-associated cancers (colon, endometrial, small bowel, hepatobiliary, pancreatic, genitourinary, or gastric), including synchronous or metachronous lesions; individuals with colon cancer and a first degree relative with an HNPCC-associated tumor and/or colonic adenoma (1 cancer diagnosed at age <45 years and the adenoma diagnosed at age <40 years); individuals with colon or endometrial cancer diagnosed at <50 years; individuals with right-sided colon cancer having an undifferentiated pattern (solid/cribiform) or signet cell histopathology diagnosed at <45 years; or individuals with adenomas diagnosed at <40 years.