Children's Hospital Colorado

Hereditary Cancer

What is cancer?

Our bodies are composed of millions of cells. As a normal process of life, our cells grow, divide and die. Cancer usually begins with a single healthy cell. Over time, damage may occur and accumulate within a cell. The damage, also called a mutation, may disrupt the cell's control mechanisms, allowing the cell to grow and divide out of control. As this cell divides into many cells, they may form a mass called a tumor. Cancer cells also have the ability to spread throughout the body, or metastasize, which may result in tumor formation in other parts of the body.

What is hereditary cancer?

Hereditary cancer is cancer that occurs in a person or family due to an inherited risk factor. In these cases, a person has a change in their genetic material that is either inherited from a parent or new in that person. This change, or mutation, increases their chances of developing certain types of cancer and is found in small pieces of genetic material called genes.

What causes hereditary cancer?

Our DNA is the genetic material in every cell that serves as the blueprint for our body development, growth and function. The DNA in our bodies forms approximately 20,000 genes. Our genes come in pairs; one of each gene is inherited from each parent. Mutations that alter the way the genes function to control cell growth and division increase the risk for cancer in people who have inherited them.

Who gets hereditary cancer?

Approximately 1 in every 2 men and 1 in every 3 women will develop some type of cancer in their lifetime; 1 in 300 during their childhood. About 1 in 10 people (including children) who develop cancer have had the diagnosis because of an inherited risk factor. It is important to remember that inheriting a predisposition to cancer does not guarantee it will occur.

Most cancer cases are not due to an inherited cause, but rather occur as a single occurrence. This sporadic occurrence of cancer accounts for approximately 80 to 85% of cancer cases. However, when we do see a cluster of cancer in a family, there are several possible explanations:

  • Chance: It may simply be chance or coincidence that several relatives have developed cancer because cancer is such a common disease.
  • Familial clustering: A family may have what is referred to as a familial clustering of cancer. A combination of genetic and environmental factors may work together to somehow increase the risk of cancer for a particular family.
  • Genetic and environmental factors: All members of a family have some genetic material in common with each other. In addition, family members often share the same environment within a single household and often have similar lifestyle habits such as smoking, alcohol use, nutrition and exercise. Approximately 10 to 15% of all cancers fall within this familial cancer category.
  • Genetic mutation: It is possible that a family may have a single gene mutation that puts certain family members at an increased risk to develop certain types of cancer. The altered gene can be passed from parent to child and results in an inherited predisposition or susceptibility to develop cancer. Approximately 5 to 10% of all cancers has an inherited cause, and it is important to remember that inheriting a predisposition to cancer does not guarantee it will occur.

Which types of cancer are hereditary?

It is possible that a family may have a single gene mutation that puts certain family members at an increased risk to develop certain types of cancer. While we do not choose which genes we inherit or pass on, the altered gene can be passed from parent to child and result in an inherited predisposition or susceptibility to develop cancer. Your doctor or genetic counselor can help you determine if your family history suggests a hereditary risk for cancer.

Sometimes children have a hereditary risk for cancer that is new in them and was not inherited from either parent. This is called de novo inheritance and there is nothing a parent could have done to have caused or prevented a de novo risk, which happens by chance during development. However, the risk is still considered to be hereditary because the child can then pass the risk on to their future children.

In general, the risk of having an inherited form of cancer is highest in the following situations:

  • Multiple family members diagnosed with cancer or tumors
  • Cancer or tumors in multiple generations
  • More than one cancer or tumor diagnosed in an individual
  • Cancer or tumor in an individual who also has two or more congenital anomalies, such as birth defects, abnormal growth or development, or other major medical issues
  • Rare or certain types of cancer or tumors, such as:
    • Adrenocortical carcinoma
    • Atypical teratoid and malignant rhabdoid tumor
    • Cardiac myxoma
    • Choroid plexus carcinoma
    • Endolymphatic sac tumor
    • Hemangioblastoma
    • Hepatoblastoma
    • Hypodiploid leukemia
    • Juvenile myelomonocytic leukemia
    • Malignant peripheral nerve sheath tumor
    • Optic pathway tumor
    • Paraganglioma
    • Pheochromocytoma
    • Renal cell carcinoma
    • Retinoblastoma
    • Rhabdomyosarcoma, especially if anaplastic or before age 6
    • Sonic hedgehog medulloblastoma
    • Thyroid cancer, especially medullary
    • Vestibular schwannoma

Get to know our pediatric experts.

Lesley Arland, PA-C

Lesley Arland, PA-C

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Roger Giller, MD

Roger Giller, MD

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Marilyn Manco-Johnson, MD

Marilyn Manco-Johnson, MD

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