10 Facts About the 'Cancer Family Syndrome'

患有林奇综合征的人具有更高的发展癌症的寿命危险，并且增加了越来越多的癌症的风险增加。这些包括结肠和直肠癌的癌症，也包括胃，小肠，肝，胆囊，尿路，脑，胰腺，前列腺和皮肤等许多其他人。女性也有增加患儿和卵巢癌的风险。

Henry Lynch, MD, for whom Lynch syndrome is named, is regarded as one of the fathers of cancer genetics for his groundbreaking work on hereditary cancers in the 1960s and 1970s. He studied a number of families in the Midwest with higher than normal incidence of cancers, particularly colon cancer, coining the term “cancer family syndrome.” Lynch was noted for using statistics to identify the genetic nature of a family’s predisposition to cancer.

Cancer begins when normal cells change and grow out of control, forming a mass called a tumor. People with Lynch syndrome have涉及不匹配修复（MMR）系统的几种基因中的突变. The林奇synd有关的基因romeinclude MLH1, MSH2, MSH6, PMS2, and EPCAM. A mutation in any of these genes gives a person an increased lifetime risk of developing Lynch syndrome-related cancers.

Lynch综合征是由MMR基因的突变引起的，这使得在将DNA被复制为细胞分裂的一部分时修复错误，就像拼写检查器在计算机上捕获错位。这些基因缺陷允许DNA错误保持留下，未经检查。作为细胞分裂，这些误差堆叠和无法控制的细胞生长可能导致肿瘤和癌症。

Lynch syndrome is a genetic condition passed from parent to child. Families that have Lynch syndrome usually havemore cases of colon cancerthan normal and are often diagnosed with colon cancer at a younger age (before 50) than the general population. The condition follows an autosomal dominant inheritance pattern, with one inherited copy of the altered gene in each cell sufficient to increase cancer risk. However, not everyone who inherits a mutation in these genes will develop cancer.

muir-torre综合症和Turcot综合征是与林奇综合征有关的遗传条件。Muir-Torre综合征的人常常培养稀有的皮肤病变，并且有风险冒着林奇经常看到的癌症。具有TURCOT综合征的人常常发育多种结肠息肉，并且具有增加的结肠直肠癌和脑癌的风险。

Lynch syndrome is themost common hereditary cause of colorectal cancer和endometrial cancer in women. It accounts for between 2-4 percent of all colorectal cancers and 2-5 percent of endometrial cancers in women. However, someone with Lynch syndrome has a 40-80 percent lifetime chance of getting colorectal cancer. Women with the condition have a 20-60 percent chance of getting endometrial cancer.

Some criteria that may be red flags for Lynch syndrome:

• Developing colon cancer younger than 50
• Developing colon cancer along with other types of cancer that are linked with Lynch syndrome.
• Colon cancer in one or more first degree relatives (parents, siblings, children) who also had another Lynch syndrome-related cancer.
• Colon cancer in 2 or more second degree relatives (aunts, uncles, grandparents, grandchildren, nephews, and nieces) who also had another related cancer.

If aclose family member had colorectal cancer at a young age或者多个亲密的家庭成员被诊断出患有结直肠癌，如果您开始筛选比正常的结肠癌，并且如果您应该更频繁地筛选，请考虑询问您的医生。您还可以考虑具有基因筛选和咨询。

A genetic test from blood or saliva can determine if you carry the mutation for Lynch syndrome. For those diagnosed with cancer, an免疫组织化学测试（IHC）may be used to determine if a tumor is caused by Lynch syndrome. Once Lynch syndrome has been discovered in a family member, other relatives can be tested for the mutation to find out if they also have it. If positive, there is a 50 percent chance that parents, children, and siblings will also have this condition.

美国临床肿瘤学会（ASCO）建议使用林奇综合征的人们每一到20至25岁开始每一到两年，或者比最早的家庭成员的诊断年龄较小，以较早的诊断。林奇综合征的妇女应考虑卵巢和子宫的筛选，具有经阴道超声和子宫内膜活组织检查。