Lynch Syndrome: HNPCC
There are many reasons to wonder about your risk of colorectal or endometrial cancer - your environment, your diet, your family history. As many as 150,000 new cases of colorectal cancer and over 40,000 cases of endometrial cancer are diagnosed each year.
While the majority of colorectal and endometrial cancers are sporadic, or not caused by inherited risk factors, research has shown that up to ten percent of these cases are due to inherited cancer syndromes. One of these inherited syndromes is known as hereditary nonpolyposis colorectal cancer (HNPCC). Individuals with HNPCC have up to an 80 percent risk of colorectal cancer and up to a 71 percent risk of endometrial cancer by age 70. This is a large risk compared to the general population's risk, which is just two percent for colorectal cancer and 1.5 percent for endometrial cancer.
Additionally, people with HNPCC may have more than one type of cancer. These cancers may be diagnosed at the same or at different times. Along with colorectal and endometrial cancer, other HNPCC-related cancers include ovarian, stomach, kidney/urinary tract, brain, biliary tract, pancreas, small bowel, and sebaceous adenomas. It is important to check your family history for these cancers in addition to colorectal and/or endometrial cancers.
Inherited Risk FactorsMany individuals are unaware of their inherited risk. Whether or not you've had cancer yourself, a family history of early onset colorectal and/or endometrial cancer, or other HNPCC-related cancers at any age, is suspicious for inherited colorectal cancer.
What do we mean by inherited colorectal cancer?
We're all born with two copies of about 30,000 different genes, one copy of each gene from our mother and the other from our father. Three genes in particular, MLH1, MSH2 and MSH6 are responsible for the majority of HNPCC. We all have these genes. When functioning normally, these genes work to prevent certain cancers. But in some cases, we can inherit a mutation in one of these genes from either parent. This mutation interferes with the normal activity of the gene, making us more susceptible to colorectal, endometrial and other types of cancer. It is important to remember that although cancer risks are increased in HNPCC, they are not 100%-therefore, not all people with HNPCC will develop cancer.
If a person has an HNPCC mutation, their parents, children, brothers and sisters may also have the same mutation. Genetic testing is the only way to accurately identify individuals who carry mutations in these genes. If genetic testing leads to a diagnosis of HNPCC in an individual, it is very important for them to share their test results with family members. hare their test results with family members.
» Reducing the Risk of Colorectal Cancer: HNPCC
There are many reasons to wonder about your risk of colorectal or endometrial cancer - your environment, your diet, your family history. As many as 150,000 new cases of colorectal cancer and over 40,000 cases of endometrial cancer are diagnosed each year.
While the majority of colorectal and endometrial cancers are sporadic, or not caused by inherited risk factors, research has shown that up to ten percent of these cases are due to inherited cancer syndromes. One of these inherited syndromes is known as hereditary nonpolyposis colorectal cancer (HNPCC). Individuals with HNPCC have up to an 80 percent risk of colorectal cancer and up to a 71 percent risk of endometrial cancer by age 70. This is a large risk compared to the general population's risk, which is just two percent for colorectal cancer and 1.5 percent for endometrial cancer.
Additionally, people with HNPCC may have more than one type of cancer. These cancers may be diagnosed at the same or at different times. Along with colorectal and endometrial cancer, other HNPCC-related cancers include ovarian, stomach, kidney/urinary tract, brain, biliary tract, pancreas, small bowel, and sebaceous adenomas. It is important to check your family history for these cancers in addition to colorectal and/or endometrial cancers.
Inherited Risk FactorsMany individuals are unaware of their inherited risk. Whether or not you've had cancer yourself, a family history of early onset colorectal and/or endometrial cancer, or other HNPCC-related cancers at any age, is suspicious for inherited colorectal cancer.
What do we mean by inherited colorectal cancer?
We're all born with two copies of about 30,000 different genes, one copy of each gene from our mother and the other from our father. Three genes in particular, MLH1, MSH2 and MSH6 are responsible for the majority of HNPCC. We all have these genes. When functioning normally, these genes work to prevent certain cancers. But in some cases, we can inherit a mutation in one of these genes from either parent. This mutation interferes with the normal activity of the gene, making us more susceptible to colorectal, endometrial and other types of cancer. It is important to remember that although cancer risks are increased in HNPCC, they are not 100%-therefore, not all people with HNPCC will develop cancer.
If a person has an HNPCC mutation, their parents, children, brothers and sisters may also have the same mutation. Genetic testing is the only way to accurately identify individuals who carry mutations in these genes. If genetic testing leads to a diagnosis of HNPCC in an individual, it is very important for them to share their test results with family members. hare their test results with family members.
» Reducing the Risk of Colorectal Cancer: HNPCC
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