Hereditary Cancer
Assessing your risk/genetic counseling
Risk assessment
Although everyone is at risk for cancer during his or her lifetime, cancer risk is individual. Many factors affect a person’s risk, including gender, age, family history, history of hormone exposure, and others. Cancer risk assessment refers to the use of tools and statistics to determine an individual’s risk for cancer. Risk assessment helps health care providers determine an individual’s best options for cancer screening, follow-up, and risk management. The benefits derived from different screening and risk management options often depend on the estimated cancer risk of an individual.
The majority of cancers have no hereditary component. It is important to remember a risk for cancer may exist even if no one in the family has had the disease. Screening tests are available and recommended for some cancers even for people who are not at high risk. The American Cancer Society publishes guidelines for cancer screening in the general population. Other screening tests are only recommended for people at high risk for cancer. It is important to talk with your health care provider about appropriate cancer screening based on your age, family history, and other factors.
Risk assessment models
Two major types of risk assessment for cancer should be recognized and distinguished.The first is an effort to define an individual’s risk to develop a certain type of cancer in his or her lifetime (or a specific period of time, such as the next 5 years). The second type of risk assessment estimates the chance that a hereditary cancer gene mutation is responsible for cancers in an individual and/or family. Both types of risk assessment require specialized tools to compile statistical data from large studies to estimate individual risk. Although experts find these models helpful, no single model can totally replace an evaluation by an expert in cancer genetics.
Breast cancer risk assessment
The Gail Model is a popular model that health care providers sometimes use to estimate a woman’s individual risk for developing breast cancer. The most widely used breast cancer risk assessment tool, it works well when used for most women. This model, however, does not incorporate certain family history critical to determining risk for hereditary breast cancer:
- It only takes into account first-degree female relatives who have had breast cancer.
- We know risk for hereditary cancer can be passed down from the mother’s side and/or the father’s side, so collecting family history from both sides of the family is important.
- Information about second- and third-degree relatives may be significant when looking at family history.
- It does not take into account whether ovarian or other less common cancers run in a family.
- Hereditary breast cancer risk is linked to ovarian cancer risk. Since ovarian cancer is rare, its presence in a family can indicate hereditary risk for breast cancer.
- Male breast cancer, although rare, significantly increases the likelihood of hereditary cause.
- It does not take into account the ages of breast cancer onset in a family.
- Premenopausal breast cancer (occurring before age 50) in a family increases the likelihood that the cancer is hereditary.
- It does not consider a person’s ethnic heritage, which may affect risk for hereditary cancer.
- Certain populations, such as people of Eastern European (Ashkenazi) Jewish descent, may be at particularly high risk for a hereditary cancer syndrome.
If your breast cancer risk is calculated using the Gail model, and you have even one of the family history features NOT accounted for in this model, your risk estimate may not be accurate. Please seek the advice of a cancer genetics expert to help you better understand your individual risks. (You can find a genetics expert by visiting our section on this topic.)
Another breast cancer risk assessment model, the Claus Model, considers breast cancer diagnoses in first- and second-degree relatives in both the paternal and maternal family history. Like the Gail Model, however, the Claus model does not consider other cancers which may signal a hereditary component, such as ovarian cancer and male breast cancer.
Genetic risk assessment
BRCAPro is a program used by experts to determine an individual’s risk of carrying a BRCA mutation—but not the risk of developing breast cancer—based on her personal and family history of breast cancer and ovarian cancer. BRCAPro does take into account ovarian cancer or male breast cancer, ages of breast cancer onset, as well as the total number of family members who have never developed breast or ovarian cancer. BRCAPro combines several different gene mutation risk models into one computer program. Cancer genetic experts know how to use these tools and understand their limitations. They also know how to determine when a risk-calculating tool is not performing as expected. Therefore, no risk assessment model can totally replace an evaluation by an expert in cancer genetics.
Genetic counseling
Our knowledge of hereditary cancer genetics is rapidly advancing as new information is being discovered at an accelerated pace. Consulting with an expert in cancer genetics is the best way to ensure receiving the most up-to-date and credible information when trying to determine risk for cancer and make decisions about risk management. Cancer genetic counselors, geneticists, and risk assessment counselors are health care providers who are specialists in hereditary diseases. They can help individuals more clearly understand their risk for hereditary cancer by:
- Reviewing the family history of cancer including information about family members who never developed cancer
- Assessing and explaining risk for hereditary cancers and/or the chance to detect a mutation through genetic testing
- Describing the benefits and limitations of genetic testing
- Describing available medical management options based on test results
- Discussing whether a person may benefit from genetic testing
- Determining which family member is the most appropriate to begin the genetic testing process in a family
- Interpreting genetic test results and explaining what they mean for you and your family in the context of your personal and family history
- Providing referrals to experts for follow-up screening and risk management
- Providing referrals to support resources and research opportunities (including research on genetic testing, screening, treatment, etc.)
- Discussing your risks and medical management options with your regular health care provider(s)
Genetic counselors help individuals and families make informed decisions about genetic testing. These specially-trained counselors provide education regarding genetics and heredity in a way that people can comprehend and use to make the best decisions for themselves. Counselors do not try to persuade people to have or avoid genetic testing; they discuss appropriate cancer screening, risk management, and follow-up care based on the most recent medical literature and individual risk. Thus, a genetic counseling appointment can even benefit individuals who decide not to pursue genetic testing. Because genetic counselors are also familiar with state and federal laws regarding information and discrimination, they can address common concerns about the privacy and confidentiality of personal genetic information.
A genetic counseling session usually involves an in-depth discussion about the family medical history. The genetic counselor will want to know family medical history going back three generations, including:
- Who in the family has been diagnosed with cancer and who has not
- The primary site of the cancers (for example, began in the breast and spread to the brain), this may require a copy of original pathology reports if available
- The age of diagnosis for any cancers in the family
- The current ages of living family members and the ages at death of those who are deceased
- Any other family health information you feel may be important or unusual
Finding a genetics specialist
Geneticists are physicians who have specialized in hereditary diseases. Certified genetic counselors are health care professionals who have had specialized training and have earned a Masters degree in genetic counseling. The National Society of Genetic Counselor website offers a searchable directory for finding a certified genetic counselor by state and specialty. (To find a genetic counselor who specializes in cancer genetics, choose "cancer" under the options "Area of Practice/Specialization"). Some healthcare facilities do not have genetic counselors on staff and for some people traveling to another facility is not possible. There is a company that provides genetic counseling consultations by telephone with board-certified genetic counselors.
Other health care providers such as nurses or oncologists may offer genetic counseling and testing. The amount of training these health care providers have received in the area of cancer genetics may vary; consequently their ability to provide comprehensive genetic counseling and interpretation of test results may also vary. It is important to know the qualifications of the person providing your genetic counseling. The Genetic Nursing Credentialling Commission (GNCC) offers a credentialling program for nurses that receive advance training in genetics. The GNCC sets a standard of competency and requires continuing education for nurses that are accreditted in by their program. You can view a list of credentialed nurses by state on their website (scroll down to the bottom of the page).
The National Cancer Institute provides a list of health care providers offering genetic counseling and testing. This tool also provides information on the certification of the health care providers listed.
Other websites
FAQs About Genetic Counselors
A brief article published by the National Society of Genetic Counselors.
Genetic Nursing Credentialling Commission (GNCC) offers a credentialling program for nurses that receive advance training in genetics. They list credentialed nurses by state on their website.
Cancer Genetics
Services Directory
This database is produced and maintained by the National Cancer Institute.
To find cancer genetics professionals who specialize in hereditary breast and
ovarian cancer, choose one or both of the BRCA options in the form's "Family
Cancer Syndrome" selection list. You can limit your search by city, state,
or country (U.S. and Canada only).
Informed Medical Decisions
This company provides full telephone genetic counseling by board-certified genetic counselors.
National Cancer Institute PDQ
The National Cancer Institute (NCI) has information on cancer genetics that is regularly updated. Included in the PDQ is a table that outlines the strengths and weaknesses of different breast cancer risk assessment models.
National Society of Genetic
Counselors Lookup Tool
Search for certified genetic counselors by specialty, city and state.
Further reading - books
Assess
Your True Risk of Breast Cancer,
Written by Patricia Kelley, PhD, a geneticist, this book provides a good overview
on assessing risk for breast cancer and also includes information specific to
hereditary breast cancer risk.
Further reading - articles (advanced reading)
Application of breast
cancer risk prediction models in clinical practice
Susan M. Domchek, Andrea Eisen, Kathleen Calzone, Jill Stopfer, Anne Blackwood,
Barbara L. Weber Journal of Clinical Oncology.
Volume 21, Issue 4, p. 593-601, February, 2003.
Breast
cancer risk assessment models: applicability to African-American women
Melissa L. Bondy, Ph.D., Lisa A. Newman, M.D Cancer.
Volume 97, Issue S1, p. 236-245, December 2002.
Clinical characteristics
of individuals with germline mutations in BRCA1 and BRCA2: analysis of
10,000 ndividuals
Thomas S. Frank, Amie M. Deffenbaugh, Julia E. Reid, Mark Hulick, Brian E.
Ward, Beth Lingenfelter, Kathi L. Gumpper, Thomas Scholl, Sean V. Tavtigian,
Dmitry R. Pruss, Gregory C. Critchfield. Journal
of Clinical Oncology. Volume 20, Issue 6: p. 1480-1490, March 2002.
Limitations
of the Gail Model in the ppecialized breast cancer risk assessment clinic
David M. Euhus, MD, A. Marilyn Leitch, MD, James F. Huth, MD, and George
N. Peters, MD. The Breast Journal. Volume 8
Issue 1: p 23, January/February 2002.
Understanding
mathematical models for breast cancer risk assessment and counseling
David M. Euhus, MD. The Breast Journal. Volume
7, Issue 4: p. 224, July 2001.
(A literature review)
The
effectiveness of the Gail Model in estimating risk for development of breast
cancer in women under 40 years of age
Gasan Mackarem, MD, Constance A. Roche, MSN, RN, CS, and Kevin S. Hughes,
MD. The Breast Journal. Volume 7, Issue 1:
p. 34-39, January 2001.