Hereditary Nonpolyposis Colorectal Cancer (HNPCC)

Hereditary Nonpolyposis Colorectal Cancer

Hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome cancer is a kind of genetic autosomal dominant state and who have a high risk of colon cancer and other cancers, including cancer of the endometrium, ovary, stomach, small intestine, hepatobiliary tract, upper urinary tract, brain, and skin. Increased risk of this cancer is inherited because of mutations that damage the repair of mismatch DNA.

HNPCC is 2-5% of all colon cancer. More than 90% of all colon tumors in patients showed that the instability of the microsatellite HNPCC (MSI-H) is high, which means that at least 2 or more genes are mutated in HNPCC families or HNPCC families are atypical.

Hereditary nonpolyposis colorectal cancer - Colon cancer in patients with HNPCC is present at an earlier age than the general population and is characterized by an increased risk of other cancers, such as endometrial cancer and at lower levels, Cancer of the ovary, stomach, small intestine, channel bile, pancreas, upper urinary tract, prostration, brain, and skin.

Hereditary Nonpolyposis Colorectal Cancer (HNPCC)

Mutations in one of these genes prevent the repair of errors of DNA replication. When the abnormal cells continue to divide, errors are collected can lead to uncontrolled cell growth and maybe even cancer.

Hereditary nonpolyposis colorectal cancer - Mutations in the gene for EPCAM also cause interference with DNA repair, although the gene itself is not involved in this process. EpCAM genes located in the gene MSH2 on chromosome 2; Gene mutation of a specific gene causes EPCAM MSH2 is turned off (inactive), interfere with DNA repair, and caused the accumulation of errors in DNA. Although mutations in these genes, that individuals tend to be affected by cancer, not all people who carry this mutation develop the tumor for cancer.

Genetic testing of mutations in the genes of repair mismatches of DNA is expensive and time-consuming, so researchers have proposed techniques for identifying cancer patients are most likely are carriers of HNPCC as candidates are ideal for testing Genetic. The Amsterdam criteria are useful but do not identify up to 30% of potential carriers of Lynch syndrome. On the patient cancer of the colon, can the pathologist measure the microsatellite instability in samples of a colon tumor, which is a marker of substitute for the mismatch DNA repair gene dysfunction? If it is detected Microsatellite instability, there is a higher possibility for the diagnosis of Lynch syndrome. See Also: Stage 4 Colon Cancer Life Expectancy Without Treatment.

Hereditary nonpolyposis colorectal cancer - Recently, researchers combined microsatellite instability profile (MSI) and testing for Immunohistochemical expression of DNA mismatch repair genes and identified an additional 32% of Lynch syndrome, which will miss out on profiling. MSI file itself. Currently, Immunohistochemical and MSI profiling strategy, he combined the most advanced way of identifying candidates for genetic testing for Lynch syndrome. Genetic counseling and genetic testing are recommended for families that meet the criteria of Amsterdam, preferably before colon cancer arises. Hereditary nonpolyposis colorectal cancer - Ultrasound with or without endometrial biopsy is recommended annually for screening for ovarian and endometrial cancer.

People with HNPCC have about an 80% lifetime risk of colon cancer. Two-thirds of these tumors occur in the proximal colon. The average age of diagnosis of cancer of the colon and rectum was 44 years for family members who meet the criteria. Also, women with HNPCC have a risk of endometrial cancer, 80% of life. The average age of diagnosis of endometrial cancer is about 46 years old.

In women with HNPCC who have cancer of the colon and endometrium, about half of which comes with cancer of the endometrium, endometrial cancer is the most common cancer in the Sentinel syndrome Lynch. In HNPCC, the average age of diagnosis of cancer aged stomach 56 years of age with intestinal-type adenocarcinoma is the most commonly reported pathology. HNPCC-related ovarian cancer has an average age of 42.5 years of diagnosis; about 30% are diagnosed before the age of 40 years. Another HNPCC-related cancer have been reported with a specific description of: cancer of the urinary tract transitional cell carcinoma was the ureter and the renal pelvis; small intestine cancer is most common in the duodenum and the small intestine are central nervous system tumors are the most commonly seen is glioblastoma.

And what of prevention? After the reported findings of the zeros of randomized controlled trials of aspirin to prevent the syndrome of the colon, Lynch, Burn and his colleagues have reported new data, representing the subsequent period is longer than stated at the beginning. The NEJM paper. The new data show a decline in incidence in patients exposed to at least Lynch syndrome four years of high doses of aspirin, with a satisfactory risk profile. This result was widely discussed in the media; Further research will look at the adjustment (lower) dosage (to reduce the risk associated with high doses of ASA).