About 10 to 15 percent of cancers are inherited, either through a single genetic change or multiple changes in a person’s DNA. Breast, ovarian, colon and endometrial (uterine) cancers are among the most common cancers that can be linked to mutations in single, specific genes. A hereditary risk for cancer could mean that one or many genetic factors may have passed from generation to generation.
Being aware of a family history of cancers—especially on the same side of the family—is a first step in determining if there is an increased risk of developing herediary cancer. Certain clues that warrant further investigation include:
- A cancer diagnosis at a younger age than expected on average for that cancer type
- Patterns of cancers in a family (e.g., breast + ovarian cancer or colon + uterine cancer)
- Rare tumor types
- Ancestry (for example, Ashkenazi Jewish individuals have an increased risk of carrying a mutation in BRCA1 or BRCA2, when there is a history of breast and/or ovarian cancer
The Center for Medical Genetics offers expert, compassionate genetic counseling and sophisticated genetic testing employing the latest technology for people with a personal or family history of cancer. In addition to focused single gene testing for many of the most common genes, we offer state-of-the-art cancer panel genetic testing. This sophisticated testing method allows us to simultaneously evaluate multiple-gene related cancer risk. These services help clarify cancer risks to guide screening or preventative management choices.
It is generally most informative if a relative who has had cancer is tested first, to determine if an identifiable gene mutation exists in the family. If a mutation is identified, at-risk family members may elect to be tested for the familial mutation; those testing positive have a significantly increased risk of developing cancer, while those relatives testing negative may be told that they have the general population risk of developing cancer. By providing a more accurate picture of the risks an individual may face, the results of genetic testing can lead to more tailored, personalized care. In many cases, medical genetics can help reassure siblings, children and other relatives that they have not inherited a familial tendency for cancer.
As genetic knowledge continues to grow, the Center takes advantage of the latest testing options available and makes them available to our community.
A genetic consultation may be appropriate for you, if you have a personal or family history of any of the following hereditary cancers, including:
Herditary Breast Cancer
Everyone faces a risk of cancer – on average 12% of women will develop breast cancer, according to the National Cancer Institute. In contrast, individuals who inherit a harmful BRCA1 or BRCA2 mutation have a much higher risk of developing breast and/or ovarian cancer.
Personal and family history and cancer types in a family help us to determine the likelihood of a hereditary breast cancer syndrome and, if a syndrome is suspected, which gene(s) should be analyzed.
When breast cancer is caused by a single gene mutation passed through the family you may see:
- Breast cancer diagnosed at an early age (e.g., under 50)
- Multiple family members (blood relatives) with cancer
- Certain combinations of related cancers (breast and ovary, sarcoma, adrenocortical carcinoma and childhood cancers) in an individual
- An individual with two or more primary cancers
- Family history of specific patterns of cancer and sometimes benign diseases (breast cancer, gastrointestinal malignancies and thyroid disease, both benign and malignant)
- Specific tumor types (e.g., “triple negative” breast cancer)
- Specific ancestry (e.g., Ashkenazi Jews have a one in 40 chance of carrying the BRACA1 or BRCA2 mutation.)
At NorthShore, genetic testing is available for BRCA1 and BRCA2 – the two most common genes known to be associated with hereditary breast and ovarian cancer as well as newer genes connected to breast cancer risk. Everyone, men as well as women, has these genes. When an individual carries an alteration in one of these genes, the chances of developing cancer increases and that risk can be passed on to the next generation.
Hereditary Colon Cancer
Hereditary colon cancer caused by a single gene mutation represents about 6 percent of colon cancer cases.
Personal and family history and cancer types in a family help us to determine the likelihood of a hereditary colon cancer syndrome and, if a syndrome is suspected, which gene(s) should be analyzed.
When colon cancer is caused by a single gene mutation passed through the family you may see:
- Colon cancer diagnosed at an early age (e.g., under 50)
- Multiple family members (blood relatives) with colon cancer on the same side of the family
- Constellation of colon cancer and uterine cancer in close family members or in an individual
- An individual with two or more primary cancers (colon and uterus)
- Three or more cases of cancer of the colon, uterus, ovaries, small bowel, ureter or renal pelvis in close relatives on the same side of the family with one of the cancers diagnosed under age 50
- Personal or family history of ovarian, small bowel or urinary collecting system (kidneys, ureter, bladder) cancers
- Personal or family history of multiple precancerous growths, such as colon polyps or other tumors (sebaceous carcinomas)
Genetic testing is available for hereditary colon cancer syndromes. The two most common hereditary colon cancer syndromes are Lynch syndrome (Hereditary Non-polyposis Colon Cancer or HNPCC), a condition in which the tendency to develop colon or rectal cancer is inherited and Familial Adenomatous Polyposis (FAP), a hereditary cancer syndrome that is characterized by the development of hundreds to thousands of adenomatous colon polyps. At NorthShore, we offer genetic testing for both of these conditions as well as others including Attenuated Familial Polyposis (AFAP), a genetic condition characterized by far fewer (tens to hundreds) of polyps compare with FAP.
Hereditary Ovarian Cancer
The National Cancer Institute estimates that a woman who has an altered BRCA1 or BRCA2 gene has an increased lifetime risk of ovarian cancer – roughly 16 to 40 percent versus 1.3 percent for a woman in the general population.
When ovarian cancer is caused by a single gene mutation passed through the family you may see ovarian cancer or other similar malignancies (fallopian tube cancer, primary peritoneal cancer) diagnosed at any age. If this is the case, a genetics consultation should be considered.
At NorthShore, we routinely perform genetic testing for BRCA1 and BRCA2 – the two most common genes known to be associated with hereditary ovarian cancer. Everyone, men as well as women, has these genes. When an individual carries an alteration in one of these genes, the chances of developing ovarian cancer are significantly higher than average. We also provide counseling and testing for other genes that may be involved in the development of ovarian cancer.
Hereditary Endometrial (Uterine) Cancer
Familial-linked endometrial (uterine) cancer is closely related to hereditary colon cancer—specifically, Lynch Syndrome (Hereditary Non-polyposis Colon Cancer or HNPCC). The gene mutations that lead to HPNCC also increase the risk of developing endometrial cancer.
Personal and family history and cancer types in a family help us to determine the likelihood of a hereditary endometrial (uterine) cancer syndrome and, if a syndrome is suspected, which gene(s) should be analyzed.
When endometrial (uterine) cancer is caused by a single gene mutation passed through the family you may see:
- Endometrial (uterine) or colon cancer diagnosed at an early age (e.g., under 50)
- Multiple family members (blood relatives) with endometrial (uterine) cancer on the same side of the family
- Constellation of endometrial (uterine) or colon cancer in close family members or in an individual
- An individual with two or more primary cancers (uterus and colon)
- Three or more cases of cancer of the uterus, colon, ovaries, small bowel, ureter or renal pelvis in close relatives on the same side of the family with one of the cancers diagnosed under age 50
- Rare tumor types (e.g., sebaceous carcinomas)
- Personal or family history of ovarian, small bowel, ureter or renal pelvis cancer
- Personal or family history of multiple precancerous growths, such as colon polyps
- Sebaceous carcinoma or keratoacanthomas +/- family history of colon and/or uterine cancer
At NorthShore, genetic testing is available for Lynch Syndrome or HNPCC, which could reveal the genetic basis of your endometrial (uterine) cancer and lead to more precise diagnosis and treatment. We also provide counseling and testing for other genes that may be involved in the development of this form of cancer.