HCC Multidisciplinary Program Facts

Colon and rectal cancer occurs more commonly in some families, and we have identified genetic mutations that significantly increase the risk in other families.
Most cancer develops sporadically — when a genetic problem occurs within a cell and causes it to start to grow and spread uncontrollably. For a smaller percentage of cancers, genetics is what drives the development and growth of cancer cells.

Genetic problems (mutations) passed down within certain families, that later develop into cancer, are called hereditary. Approximately 5-10% of colorectal cancers are strongly associated with hereditary risks, while another 20% or more are not as well-defined, but are likely inherited — or are a combination of genetics interacting with environmental factors like poor dietary habits.

Some factors suggesting a family may have a hereditary risk for cancer include:

  • Close family members (parents, siblings) diagnosed with the same cancer
  • Several family members and/or generations diagnosed with more than one cancer
  • Cancer that is diagnosed before age 50

Hereditary colorectal cancer types

There are two main types of hereditary colorectal cancer:

  • Lynch syndrome, also called hereditary nonpolyposis colorectal cancer, is usually found in families with multiple generations of people diagnosed with colon cancers at age 50 or younger. People found to have Lynch have a 50-80% lifetime risk of developing colorectal cancer; tend to develop it at younger ages; and females with the mutation have a 40-60% risk of developing endometrial cancer.
  • Familial adenomatous polyposis (FAP) causes hundreds, sometimes thousands, of polyps to develop in the colon and tends to develop in young people. If not caught early, the risk of colon cancer developing by age 40 is nearly 100%.

Most hereditary colorectal cancers are associated with Lynch syndrome; and Lynch syndrome can lead to other cancers, including stomach (gastric), endometrial (uterine), ovarian, small intestine, liver, gallbladder, bile duct, kidney, bladder, brain and skin.