CC Nov 2015 Hereditary colorectal cancer

echoecho's version from 2015-12-29 14:05


Question Answer
Approximately ____% of patients with colorectal cancer (CRC) have a definable genetic mutation predisposing them to colorectal CA?5
List the most common causes of genetic mutation prediposing them to CRC?1) hereditary nonpolyposis colorectal cancer (HNPCC) 2) familial adenomatous polyposis (FAP) 3) attenuated FAP 4) MUTYH-associated polyposis (MAP)
List other rare hereditary colorectal carcinoma syndromes (and their associated abnormalities)?1) Gardern's syndrome (osteomas, fibromas) 2) Turcot's syndrome (brain tumors) 3) Peutz-Jeghers syndrome (bowel hamartomas) 4) Cowden's syndrome (breast, thyroid carcinoma)
These rare hereditary types account for < ______% of cases of CRC?0.1
What disease accounts for 75-80% of hereditary CRC?HNPCC (hereditary nonpolyposis colorectal cancer (Lynch syndrome)
HNPCC or Lynch syndrome is what type of genetic disorder?autosomal dominant disorder with high penetrance
In HNPCC or Lynch syndrome, is there a modest increase in polyp formation?yes
*** HNPCC is caused by a _____ cell mutation in 1 of 6 DNA mismatch repair genes?germ
*** The HNPCC or Lynch results in what defects?1) preservation of damaged DNA 2) more rapid accumulation of cancer 3) causing mutations and a shortened progression from benign polyp to overt malignancy
In sporadic colon cancer, the evolution from a benign to a malignant polyp may take ___ to ___ years?10; 12
In HNPCC, this time period is shortened to ___ to ___ months?18, 24f
HNPCC also is associated with an increased frequency of tumors located in other organs, list the 6 cancers categories with lifetime risk %?1) colorectal cancer (70-80%) 2) endometrial (60%) 3) gastric / small bowel (13%) 4) ovarian (12%) 5) renal pelvis/ureter (4%) 6) hepatobiliary (2%)
*** The International Collaborative Group (ICG) developed criteria for identifying individuals at risk of HNPCC. The Amsterdam II criteria were updated in 1999. List the 4 main criteria?1) at least 3 relatives with an hereditary nonpolyposis colorectal cancer (HNPCC) - related cancer, one of whom must be the first-degree relative of the other two 2) involvement of 2 or more generations 3) at least 1 case occurring before age 50 years 4) exclusion of FAP syndromes
How is the above criteria easily remembered?3-2-1 (a shortened format [Amsterdam Plus] provides similar results with smaller family sizes needed
The sensitivity of the Amsterdam criteria is ____%?50
More than half of patients fulfilling the Amsterdam criteria have abnormal genetic studies consistent with what (but all including those with normal genetic studies should be managed as if they have this?HNPCC (hereditary nonpolyposis colorectal cancer)
THe modified Bethesda system has also been develope do identify what? Website?1) risk for HNPCC 2)