Family health history is a non-modifiable risk factor—or is it?

“I met three different women who had been tested [genetic testing for mutations in the BReast CAncer susceptibility (BRCA) genes] early on, in 1996, when the BRCA test first came out. They told me their family history story of mothers, aunts, uncles, and a dad who suffered from breast or ovarian or related cancers, and it was heartbreaking. But then the story changed with them. They were diagnosed with cancer, they got testing, and they shared this information with their family members. So they had stories of children and grandchildren—one woman even had great grandchildren—who were old enough to decide whether or not they wanted to be counseled and some decided to get testing. Many did not carry any of the mutations in the family, and others did. And those who found out that they were a mutation carrier, they had actual things to do. And none of them—none of those family members as we cascade down—have died of cancer.” Summer Lee Cox, Oregon Public Health Division

When considering risk factors for chronic diseases (like diabetes and heart disease), family health history is often included in the list of non-modifiable risk factors (like race/ethnicity and age), suggesting that family health history cannot be changed. While it is true that you can’t change the past, knowledge and use of your family health history information can change your family’s future health history, as illustrated in the story above.

Family health history is sometimes used interchangeably with genetics, but family health history captures more than just that. Family health history also includes shared behaviors, environments, and cultures. For example, your mother’s genes may have contributed to her type 2 diabetes and you may share some of those genes, but the fact that she lives in an area where healthy foods are harder to get and where there are few opportunities for exercise also influences her health, and you might share some of these challenges, too.

Your family’s past health history can help you understand what conditions you are at higher risk of developing. However, having a family health history of a disease does not mean that you will get that disease. For some conditions, knowing about your family health history might encourage you to make lifestyle changes, such as exercising or quitting smoking, that can lower your risk of developing that condition. For other conditions, the intervention might include medication, or earlier or more frequent screenings. Sometimes taking control of your family health history information to change your future can involve tough choices. For example, while women with a BRCA mutation can choose to have more frequent screenings or take medication, the intervention that works best for many of them—in terms of lowering risk of developing and dying from breast or ovarian cancer—may be surgery. This topic made news when Angelina Jolie wrote a New York Times Op-Ed about her decision to have a preventive double mastectomy after learning that she carried a BRCA1 mutation. She wrote about her own family health history, of her mother who did not live to see her grandchildren grow up, and of her desire to write her own new chapter in her family health history, one in which she would live to know her grandchildren.

Current guidelines, including those from the U.S. Preventive Services Task Force (USPSTF), recognize the importance of family health history in identifying those at higher risk for a condition. In some cases, the guidelines recommend that those with a family health history get screened at a younger age. For example, if you are a man  whose dad had a heart attack before age 50, the USPSTF recommends starting cholesterol screening at age 20 rather than waiting till age 35, the age recommended for men in the general public.¹ Likewise, if you are a white woman whose mother fractured her hip, the USPSTF recommends starting screening for osteoporosis at about age 55, whereas a woman with no risk factors can wait until age 65.²

While cholesterol and osteoporosis screening guidelines recommend earlier screening for those with a high risk family health history, other guidelines recommend screening or treatment only to those with a high risk family health history. For example, the BRCA genetic testing that Angelina Jolie had is not recommended for all women. Instead, the USPSTF recommends genetic counseling and, if indicated after counseling, BRCA genetic testing only for those women with a high risk family health history of breast, ovarian, or other cancers known to be associated with BRCA mutations.³ In other cases, family health history is one of several risk factors used to identify those who should receive screening or treatment. For example, the USPSTF recommendation on the use of tamoxifen and raloxifene (drugs that can decrease risk of developing breast cancer in some women) includes family health history in considering which women should be prescribed these or similar medications.⁴

We know that family health history can make people aware of their risk of developing a disease so that they can take steps to prevent the disease. But do they make changes that can alter their family health history in the future? Research suggests that they do. Studies have shown that awareness of family health history of chronic conditions like diabetes can motivate people to engage in healthier behaviors, including eating more fruits and vegetables and exercising more.^5-9 Research shows that people who know about their family health history are more likely to get necessary screenings, including cholesterol screening for those with a family health history of heart disease and colon cancer screening for those with a colon cancer family health history.^6-9 Furthermore, doctors are more likely to discuss these preventive measures when their patients tell them about their family health history.^6-9 Family health history also affects uptake of more invasive interventions. A recent study study¹⁰ of unaffected women with BRCA mutations found that women with a close relative (such as a sister, mother, or aunt) who died of breast cancer were more likely to opt for prophylactic mastectomies.

Relegating family health history to the list of genetic, non-modifiable risk factors suggests that family health history is only about inherited genetic mutations and that families cannot do anything to change their family health, in the past or the future. In doing this, we may do a disservice to those with a high risk family health history, dooming them to repeat the past rather than learn from it. Not only that, but we may take away the control that family health history can give us all, the ability to use the past to change the future. By making use of the many public health interventions available to improve their health, families can show that family health history is indeed a modifiable risk factor.

References

1. Final Recommendation Statement: Lipid Disorders in Adults (Cholesterol, Dyslipidemia): Screening
2. U. S. Preventive Services Task Force. Screening for osteoporosis: U.S. preventive services task force recommendation statement. Ann Intern Med 154, 356-364, doi:10.7326/0003-4819-154-5-201103010-00307 (2011).
3. Moyer, V. A. & U. S. Preventive Services Task Force. Risk assessment, genetic counseling, and genetic testing for BRCA-related cancer in women: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 160, 271-281, doi:10.7326/M13-2747 (2014).
4. Moyer, V. A. & U. S. Preventive Services Task Force. Medications to decrease the risk for breast cancer in women: recommendations from the U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 159, 698-708, doi:10.7326/0003-4819-159-10-201311190-00717 (2013).
5. Ruffin, M. T. t. et al. Effect of preventive messages tailored to family history on health behaviors: the Family Healthware Impact Trial. Annals of family medicine 9, 3-11, doi:10.1370/afm.1197 (2011).
6. Zlot, A. I. et al. Influence of family history of diabetes on health care provider practice and patient behavior among nondiabetic Oregonians. Prev Chronic Dis 6, A27 (2009).
7. Zlot, A. I., Cox, S. L., Silvey, K. & Leman, R. The effect of chronic disease family history on healthcare provider practice and patient behavior among Oregonians. Public Health Genomics 15, 189-200, doi:10.1159/000335555 (2012).
8. Zlot, A. I., Silvey, K., Newell, N., Coates, R. J. & Leman, R. Family history of colorectal cancer: clinicians’ preventive recommendations and patient behavior. Prev Chronic Dis 9, E21 (2012).
9. Zlot, A. I., Valdez, R., Han, Y., Silvey, K. & Leman, R. F. Influence of family history of cardiovascular disease on clinicians’ preventive recommendations and subsequent adherence of patients without cardiovascular disease. Public Health Genomics 13, 457-466, doi:10.1159/000293991 (2010).
10. Singh, K. et al. Impact of family history on choosing risk-reducing surgery among BRCA mutation carriers. Am J Obstet Gynecol 208, 329 e321-326, doi:10.1016/j.ajog.2013.01.026 (2013).