Hereditary Non Polyposis Colorectal Cancer(HNPCC) From clinic to genetics

From clinic to genetics

Question 1) Clinical pattern of inheritance of the HNPCC-Syndrome?

Question 1) Clinical pattern of inheritance of the HNPCC-Syndrome? Autosomal dominant

Question 2) Incidence of HNPCC in relation to all colorectal cancer?

Question 2) Incidence of HNPCC in relation to all colorectal cancer? Between 2-4% and 5% (older studies mentioning up to 10%)

Question 3) Concerning colorectal cancer: Penetrance? Specific anatomic site?

Question 3) Concerning colorectal cancer: Penetrance? 50-80% Specific anatomic site? right sided colon

Question 4) Histological features of colorectal cancer in HNPCC:

Question 4) Histological features of colorectal cancer in HNPCC: - Poorly differentiated -Mucinous - Large numbers of infiltrating lymphocytes

Question 5) 2 nd most often cancer involved Kind? Penetrance? Incidence in respect of all cancers of its kind?

Question 5) 2 nd most often cancer involved Kind? endometrial Penetrance? 40-60% Incidence in respect of all cancers of its kind? 2%

Question 6) 3 rd and 4 th most often cancer involved?

Question 6) 3 rd and 4 th most often cancer involved? -Stomach -Ovary

Question 7) Stomach, and ovary cancer s penetrance?

Question 7) Stomach, and ovary cancer s penetrance? - Stomac 11-19% - Ovary 9-12%

Question 8) Other associated cancers (penetrance about 5% or less)?

Question 8) Other associated cancers (penetrance about 5% or less)? - Hepatobilary 2-7% - Upper urinary tract (ureter/renal pelvis) 4-5% - Pancreatic 3-4% -Small bowel 1-4% - CNS (glioblastoma) 1-3%

Question 9) Two clinical models implying HNPCC:

Question 9) Two clinical models implying HNPCC: - Amsterdam Criteria II - Revised Bethesta Guidelines

Question 10) Amsterdam Criteria II?

Question 10) Amsterdam Criteria II: 3 relatives with colorectal, endometrial, small bowel, ureter, or renal pelvis cancer; all of the following must be met: I. One affected individual is first degree relative of the other 2 II. At least two successive generations affected III. At least one tumor diagnosed before the age of 50 years IV. Familial adenomatous polyposis has been excluded

Question 11) Revised Bethesda Guidelines?

Question 11) Revised Bethesda Guidelines: Requires at least one of the following: I. CRC diagnosed with less than 50 years of age II. Presence of synchronous, metachronous CRC, or other LS-associated tumor [a], regardless of age III. CRC diagnosed with less than 60 years of age presenting MSI-histology[b] IV. CRC diagnosed in an individual and one or more first degree relatives with an LS-associated tumor[a], with at least one of the cancers being diagnosed under age 50 years V. CRC diagnosed in an individual and two or more first or second degree relatives with LS-associated tumorsa, regardless of age a: Endometrial, stomach, ovarian, pancreas, ureter, and renal pelvis, biliarytract, and brain tumors, sebaceous gland adenomas and keratoacanthomas, and carcinoma of the small bowel b: Tumor infiltrating lymphocytes, Crohn s-like lymphocytic reaction, mucinous/signetring differentiation, or medullary growth pattern

Question 12) Laboratory tools to prove HNPCC?

Question 12) Laboratory tests to prove HNPCC? - mismatch repair genes using immunohistochemistry - microsatelite-instability using PCR(comparing length of noncoding DNA-repeats in tumour and normal tissue/leucocytes) - Commercial PCR-kits analyzing the 4 involved mismatch repair genes and EpCAM(most expensive)

Question 13) Laboratory tests to prove HNPCC? - mismatch repair genes using immunohistochemistry - microsatelite-instability using PCR (comparing length of noncoding DNA-repeats in tumour and normal tissue/leucocytes) - Commercial PCR-kits analyzing the 4 involved mismatch repair genes and EpCAM(most expensive) Which test has to be used in a healthy relative?

Question 13) Laboratory tests to prove HNPCC? - mismatch repair genes using immunohistochemistry - microsatelite-instability using PCR (comparing length of noncoding DNA-repeats in tumour and normal tissue/leucocytes) - Commercial PCR-kits analyzing the 4 involved mismatch repair genes and EpCAM(most expensive) Which test has to be used in a healthy relative? PCR-kit to analyzing mismatch repair genes directly

Question 14) How to screen for colorectal cancer in healthy relatives?

Question 14) How to screen for colorectal cancer in healthy relatives? - Colonoscopy, every 1-2y, beginning at age 20-25

Question 15) How to handle endometrial cancer prophylaxis in healthy relatives?

Question 15) How to handle endometrial cancer prophylaxis in healthy relatives? - Hysterectomy/Salpigo-oophorectomy after childbearing -(gynecological screening starting at 30 is an issue of discussion)

Question 16) How to handle other cancer prophylaxis in healthy relatives?

Question 16) How to handle other cancer prophylaxis in healthy relatives? -(Upper Endoscopy every 1-2y, starting at 30-35 maybe) -(Urinalysis annualy, starting at 30-35 maybe) - Annual physical examination including examination of the skin to look for sebacous carcinoma

Genetics

Question 17) The 4 mismatch repair genes involved in HNPCC:

Question 17) The 4 mismatch repair genes involved in HNPCC: MSH2 MLH1 MSH6 PMS2 (EpCAM epithelial cell adhesion molecule EpCAM-MSH2 fusion transcripts)

Question 18) The 4 mismatch repair genes involved in HNPCC: MSH2 MLH1 MSH6 PMS2 (EpCAM epithelial cell adhesion molecule EpCAM-MSH2 fusion transcripts) Frequency?

Question 18) The 4 mismatch repair genes involved in HNPCC: MSH2 with MLH1 90% MLH1 MSH6 10% PMS2 few (EpCAM epithelial cell adhesion molecule EpCAM-MSH2 fusion transcripts) estimated 6% Frequency?

Question 19) mismatch repair genes family?

Question 19) mismatch repair genes family? Toumor suppressor gene

Question 20) Subgroups of toumor suppressor genes?

Question 20) Subgroups of toumor suppressor genes? A) Caretakers (mismatch repair genes) keep DNA stable -keep DNA stable -cells prone to mutations of other genes -Penetrancehigh but not 100% (e.g. NHPCC 80%) B) Gatekeepers (e.g. APC) prevent uncontrolled proliferation - opens gate to proliferation - Penetrance 100% (e.g. FAP 100%)

Question 21) mismatch repair genes how many allele(s) have mutations on germ line level?

Question 21) mismatch repair genes how many allele(s) have mutations on germ line level? One

Question 22) mismatch repair genes how many allele(s) need to be mutated to develop cancer?

Question 22) mismatch repair genes how many allele(s) need to be mutated to develop cancer? Two

Question 23) mismatch repair genes how many allele(s) have mutations on germ line level -One how many allele(s) need to be mutated to develop cancer Two Explanation of this paradox?

Question 23) mismatch repair genes how many allele(s) have mutations on germ line level -One how many allele(s) need to be mutated to develop cancer Two Explanation of this paradox? Highly proliferative tissue, high chance of 2 nd mutation during lifetime double hit theory