Secondary prevention strategies focus on early detection of cancer by promoting regular screening and awareness of symptoms of cancer in order to provide medical intervention at early, curable stages of disease (2,3). 

However, these strategies are not 100% effective, and currently no known prevention strategies will completely eliminate all risk for developing or dying from breast or ovarian cancer (2,3).  

In a minority of women, inherited changes in single genes are associated with an increased risk of developing breast and ovarian cancer.  Inherited changes in the BRCA1 and BRCA2 (Breast Cancer 1 and 2, respectively) genes are associated with 5-10% of all cases of breast cancer (4) and about 10% of cases of ovarian cancer (5).  The characteristics of people who have inherited a genetic susceptibility for breast and ovarian cancer may include a strong family history of the disease, a personal or family history of breast or ovarian cancer before age 50, a personal or family history of cancer that starts in more than one place in the body, or a family history of male relatives with breast cancer. (4).  Many people who have inherited a genetic susceptibility never develop cancer, though they may pass this genetic susceptibility on to their offspring (4). 

What is the role of public health in genetic testing for breast cancer susceptibility and how does genetic testing fit into the overall public health strategy for preventing breast and ovarian cancer?  Broadly, the role of public health programs and policies is to assure, to protect, and to improve the health of the population. Although these roles in relation to genetic tests are still being defined, some functions can be suggested. In the role of the honest broker of information, public health institutions should collect and analyze the facts about genetic testing for susceptibility for breast and ovarian cancer and other genetic tests in order to provide balanced and accurate information to the population, especially for those people who might be considering this testing.  This information should include a description of the test, examples of appropriate applications of the test, and criteria for seeking further medical evaluation (6).

Public health policies are needed that will assure that women who may be candidates for testing are appropriately referred for genetic services to determine whether genetic testing or other interventions would be useful for their medical care (7,8).  These same policies should also assure that publicly funded genetic services meet or exceed clearly defined minimum standards for quality (7,8). In the case of genetic tests, these standards should address the analytical validity, the clinical validity and the clinical utility of these tests (6). 

High quality genetic testing services are useful only if they are applied appropriately, if they are accessible to the persons who might benefit, and if they result in improved outcomes.  Systematic data collection efforts are needed to comprehensively monitor how these tests are being used, who is using them and the associated clinical outcomes (9). In order to accomplish this, information should be collected on the clinical indications for genetic testing, the associated genetic test results and clinical presentation, as well as demographic information on tested people (9).  Additionally, data on the clinical outcomes of women who have had a genetic test should be linked with the clinical management strategies employed in their care (9).  This type of population-based data analyzed from epidemiological, medical and health economic perspectives would provide the means to estimate the frequency of inherited BRCA gene changes within specific populations, and the burden of cancer attributable to BRCA in these populations. This data would also be useful for shaping guidelines for clinical practice. 

Finally, public health agencies need to develop systems to monitor how personal genetic information is used and to advocate for public policies on genetic information that are fair to all that have interest in and applications for this information. Concerns about the confidentiality of genetic test results and the uses of genetic information beyond the clinical encounter are a barrier for many people who might benefit from genetic testing as a part of their clinical management (10). Although little evidence exists to suggest that discrimination due to a positive test result for breast and ovarian cancer susceptibility occurs more than rarely, many people seeking this testing are fearful of this possibility. As many as a quarter of patients decline testing at least partly due to these fears (10).  Ultimately appropriate safeguards that address these concerns must be in place to address these concerns so that genetic information can be optimally employed to improve health and prevent disease (8). 

The role of public health is to assure that genetic tests are maximally useful to improve health and prevent disease by providing accurate information, by assuring the quality of care, by collecting and evaluating population-based data on the use genetic tests and the associated clinical outcomes and assuring that genetic information is used fairly.  In the end, this data  will lead to knowledge that will be useful for women and their healthcare providers in making management choices associated with the best possible outcomes and will assure that these genetic resources are used cost effectively to benefit the whole population.

References

1. American Cancer Society: Estimated new cancer cases and deaths by gender, United States, 2002, Cancer Facts and Figures 2002. Available at http://www.cancer.org/downloads/STT/CancerFacts&Figures2002TM.pdf 
   (Accessed January 8, 2003)
2. National Cancer Institute, National Institutes of Health: Breast cancer (PDQ): prevention. Last modified December 12, 2002. Available at http://www.cancer.gov/cancerinfo/pdq/prevention/breast/healthprofessional/  
   (Accessed January 9, 2003)
3. National Cancer Institute, National Institutes of Health: Ovarian cancer (PDQ): prevention. Last modified October 10, 2002. Available at http://www.cancer.gov/cancerinfo/pdq/prevention/ovarian/healthprofessional/ 
   (Accessed January 9, 2003)
4. National Cancer Institute, National Institutes of Health: Genetics of Breast and Ovarian Cancer (PDQ):  Introduction. Last modified December 18, 2002. Available at http://www.cancer.gov/cancerinfo/pdq/genetics/breast-and-ovarian 
   (Accessed January 9, 2003)
5. Narod SA, Boyd, J.  Current understanding of the epidemiology and clinical implications of BRCA1 and BRCA2 mutations for ovarian cancer.  Feb 2002.  Curr Opin Obstet Gynecol.14(1):19-26.
6. The Secretary’s Advisory Committee on Genetic Testing. Enhancing the oversight of genetic tests:  recommendations of the SACGT. July 2000. National Institutes of Health, 6000 Executive Boulevard, Suite 302, Bethesda, Maryland 20892. Available at  http://www4.od.nih.gov/oba/sacgt.htm  
   (Accessed January 9, 2003)
7. Council of Regional Networks for Genetic Services (CORN).  Guidelines for Clinical Genetic Services for the Public’s Health.  1^st Edition, CORN, Atlanta, GA 1997.
8. Kaye C, Laxova R, Livingston JE, et al. Integrating genetic services into public health—guidance for state and territorial programs from the National Newborn Screening and Genetics Resource Center (NNSGRC). 2001. Comm Genet 4:175-196.
9. National Cancer Institute, National Institutes of Health: Genetics of Breast and Ovarian Cancer (PDQ):  Interventions. Last modified December 18, 2002. Available at http://www.cancer.gov/cancerinfo/pdq/genetics/breast-and-ovarian 
   (Accessed January 9, 2003)
10. Peterson EA, Milliron KJ, Lewis KE, Goold SD, Merajver SD.  Health insurance and discrimination concerns and BRCA1/2 testing in a clinic population.  2002.  Cancer Epidemiology, Biomarkers and Prevention 11:79-87