Gail Model for Breast Cancer Risk Assessment

When to the use the gail model: Using the Gail Model to Help Your Patients
The Gail model is a nationally accepted epidemiologic model for identifying women at higher inherited risk for breast and ovarian cancer based on family history.

What is the Gail Model?
The Gail model...
􀂃 was developed by Gail and colleagues at the National Cancer Institute;
􀂃 is widely used to quantify an individual woman's risk of developing breast cancer, usually for clinical counseling purposes or to determine eligibility for clinical trials;
􀂃 allows one to estimate the likelihood that a woman of a given age with certain risk factors will develop breast cancer over a specified time interval;
􀂃 is based on data from the Breast Cancer Detection and Demonstration Project, a mammography screening project involving over 280,000 women that was conducted between 1973 and 1980;
􀂃 was developed by looking at a number of potential risk factors for breast cancer;
􀂃 uses five significant predictors of a woman's lifetime breast cancer risk:
1. current age
2. age at menarche
3. number of breast biopsies
4. age at first live birth
5. number of first-degree relatives with breast cancer


How Are Risks Calculated With the Gail Model?
In order to use the model, the five pieces of information listed above must be known. The easiest way to use the Gail model is through an interactive computer program which asks the user to enter the necessary information and then immediately calculates the patient's cumulative breast cancer risk over the next 10, 20, and 30 years. The program, intended primarily for health-professional use, is available online as a Breast Cancer Risk Assessment Tool at the National Cancer Institute's web site.
Published tables and graphs by Gail et al. (1989) may also be used to manually calculate the relative risk and estimated cumulative probabilities of breast cancer for an individual woman. However, use of these tables and graphs is time-consuming and subject to error because of the hand calculations required than use of the computer program.
Gail MH, Brinton LA, Byar DP, et al: Projecting individualized probabilities of developing breast cancer for white females who are being examined annually. J Natl Cancer Inst 81:1879-86 (1989).
Benichou J, Gail MH, Mulvihill JJ: Graphs to estimate an individualized risk of breast cancer. J Clin Oncol 14:103-110 (1996).

What Does the Gail Model Tell Me?
Cumulative risks of breast cancer calculated by the Gail model may be used in a clinical setting to provide individualized information to women about their breast cancer risk. Using the Gail model, clinicians may:
􀂃 identify women who are at increased risk;
􀂃 discuss modified options for breast cancer screening, such as beginning mammography at a younger age or having more frequent clinical breast examinations;
􀂃 provide reassurance to many women who had previously overestimated their risk of breast cancer.

What Are Its Limitations?
Studies that have attempted to validate the Gail model found that it over-predicts the risk of breast cancer among women age 35 to 61 who do not receive annual mammograms.
The overestimation is more marked in pre-menopausal women and in those with an extensive family history. The model...
􀂃 was developed based on data from women receiving annual mammograms, and thus its most appropriate use is among this population of women, and
􀂃 does not take into account the ages at which affected relatives were diagnosed with breast cancer, nor does it consider a history of breast cancer on the father's side of the family (because only first-degree relative are considered).
Thus, women who have a history of close (first-, second-, and third-degree) relatives with early-onset breast cancer may benefit from the use of other models, such as the Claus model.
Risk-assessment models are not appropriate for women with family histories that are strongly suggestive of an inherited cancer syndrome or in families in which a specific genetic mutation in a gene such as BRCA1 or BRCA2 has been identified. Instead, such women should be counseled based on their position in the family pedigree...and the chance that they inherited the mutation that has been identified or is likely to exist in their family.
Related Information
􀂃 Breast Cancer
􀂃 Cancer Risk Counseling
􀂃 The Claus Model
This page is part of The Genetics
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Link to online calculator:
Before using the tool, please note the following:


The Breast Cancer Risk Assessment Tool was designed for use by health professionals. If you are not a health professional, you are encouraged to discuss the results and your personal risk of breast cancer with your doctor.


The tool should not be used to calculate breast cancer risk for women who have already had a diagnosis of breast cancer, lobular carcinoma in situ (LCIS), or ductal carcinoma in situ (DCIS).


The BCRA risk calculator may be updated periodically as new data or research becomes available.


Although the tool has been used with success in clinics for women with strong family histories of breast cancer, more specific methods of estimating risk are appropriate for women known to have breast cancer-producing mutations in the BRCA1 or BRCA2 genes.


Other factors may also affect risk and are not accounted for by the tool. These factors include previous radiation therapy to the chest for the treatment of Hodgkin lymphoma or recent migration from a region with low breast cancer rates, such as rural China. The tool's risk calculations assume that a woman is screened for breast cancer as in the general U.S. population. A woman who does not have mammograms will have somewhat lower chances of a diagnosis of breast cancer.


For information to help your patients understand cancer risk visit http://understandingrisk.cancer.gov. This interactive Web site will help your patients make informed decisions about how to lower their risk.