General Information

• One out of three Americans will develop cancer sometime in their lifetime.
• The cancer process usually begins when one cell grows and multiplies uncontrollably, forming a tumor that can spread to different parts of the body. This is a several step process and may take many years.
• Generally, the risk of developing cancer increases as we get older. In fact, most cases of cancer are diagnosed in people over age 55. However, a family history of cancer can increase the risk to develop certain types of cancer, even before age 50 .
• Individuals at average risk for cancer (no personal or family history of medical conditions, exposures and/or cancers that would increase risk) should follow the recommended cancer screening guidelines for the general population
• Individuals at increased risk for cancer (those at known or suspected increased risk due to personal or family history of certain medical conditions, exposures and/or cancers) may need to begin screening at an earlier age.
• All cancer is genetic, but not all cancer is inherited.

What Do The Terms “Genetic” And “Inherited” Mean?

• “Genetic” means caused by a change in the genes, which are the units of instruction in most cells of our body that control our normal growth and development.
• “Inherited” or inheritance refers to characteristics or qualities we receive from our parents as a result of their passing on genes contained in their egg or sperm cells.
• Most cases of cancer (about 90%) occur by chance, starting in one cell in a specific site (organ) of the body. This cannot be passed on to the next generation (our children).
• Some individuals (about 10% of cases) are at increased risk for developing cancer because they inherited a gene change from either of their parents that makes them more susceptible to certain cancer(s). However, even with inherited risk for cancer, other genetic factors and environmental (not inherited) factors play a role in whether or not cancer will actually develop.

Common Terms

Cancer risk assessment – The process of evaluating and interpreting an individual’s chance to develop cancer based on personal and/or family history of medical conditions, exposures, and/or cancers.

First degree relatives – Those persons with a direct, close blood relationship such as mother, father, brothers, sisters and children.

General population risk – Refers to persons who are not known to have any medical conditions, family history of cancer or specific exposures that would increase the risk of developing certain type/s of cancer.

Genes – The units of instruction in most cells of our body that control our normal growth and development.

Gene mutation – A change or alteration in a gene which affects the gene's ability to function normally.

Genetic counseling – At RPCI, this is a service provided by health care professionals with specialized graduate degrees and experience in the areas of medical genetics and counseling. During a genetic counseling consultation, information and support is provided to individuals who have a personal or family history of cancer and who may be at risk for an inherited condition. Information gathered is interpreted in terms of the risk for specific cancers, assessment for an inherited cancer susceptibility syndrome, risk to children and other relatives, and options for screening and genetic testing.

Genetic pedigree – A diagram of a family tree representing the ancestral history. See below.






Genetic testing – Allows for the possible identification of a change in a gene, which may play a role in the development of or risk for cancer or other medical conditions.

Increased risk – Refers to persons who have, or are suspected to have, a higher likelihood (compared to the general population) of developing a certain cancer/s due to personal and/or family history of medical conditions, exposures, and/or cancers.

Inherited (inheritance) - Refers to characteristics or qualities we receive from our parents as a result of their passing on genes contained in their egg or sperm cells.

Inherited susceptibility to cancer – The transmission of a changed or mutated cancer susceptibility gene from parent to child through the egg or sperm. One who inherits a mutated cancer susceptibility gene has an increased risk (above the general population risk) to develop cancer. This does NOT imply that the person has a predisposition or a 100% chance to develop cancer.

Maternal relatives – Those persons who share a blood relationship with the mother’s side of the family.

Paternal relatives – Those persons who share a blood relationship with the father's side of the family.

Registries – Compiled data on individuals and families with cancer. Selected persons may choose to join a registry. The Clinical Genetics Service works with the cancer registries at RPCI including colorectal, breast, ovarian, pancreas and sarcoma. A genetic registry of families with non-site specific cancers is also being developed. Registry participants may be candidates to participate in research studies to better understand cancer and its genetic basis, which may ultimately lead to treatments and cures for cancer.

Second degree relatives – Those persons with a less direct, but close blood relationship such as aunts, uncles, nieces, nephews, grandparents and grandchildren.