HNPCC Info

Somatic mutations in the hMSH2 gene in microsatellite unstable colorectal carcinomas. A L Børresen et al. Human molecular genetics 4 (11), 2065-72 (Nov 1995) Microsatellite instability is frequently seen in tumors from patients with hereditary nonpolyposis colorectal cancer (HNPCC). Germline mutations in the mismatch repair gene hMSH2 account for approximately 50% of these cases. Tumors from sporadic cases also exhibit this microsatellite instability phenotype, although at a lower frequency, and very few somatically derived mutations have so far been reported in such tumors. In this study DNA from 23 primary colorectal carcinomas (four familial and 19 sporadic cases) exhibiting microsatellite instability were screened for mutations in the hMSH2 gene using constant denaturant gel electrophoresis (CDGE). Among the sporadic cases, five (26%) were found to have somatically derived mutations. One tumor revealed two different mutations, possibly leading to a homozygous inactivation of the ge...

So after the surgery and the drama what kind of surveillance should a HNPCC carrier have? Since they are at risk for other abdominal cancers like liver, pancreatic, uterine, ovaries, kidneys and small bowel. Some tests that can be done are transvaginal ultrasounds, ultrasound of the kidneys, upper GI, small bowel follow through, sigmoidoscopy, endoscopic exam of the upper GI just to name a few. After surgery, it probably should be determined who will do the followup, the surgeon, gastroenterologist or your primary care physician. The decision would likely depend on who is most knowledgeable about risk factors and current best practice. I will describe some of these tests in upcoming days, so that you can find out what those experiences are like.