Personalized Medicine: Risk Perceptions, Screening Behaviors, Communication in Breast Cancer

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In honor of Breast Cancer Awareness Month, we wanted to share with you some of the groundbreaking breast cancer research BYU College of Nursing Assistant Professor Deborah Himes is currently working on. This article can also be found in our Fall 2015 edition of “Learning the Healer’s Art.”

As we move into what has been termed the genomic era of medicine, primary care physicians must be prepared to care for the unique attributes of individual patients, right down to their DNA mutations. It is most effective to provide intensive screening and preventive care for those individuals with the most risk, a variable which is determined and influenced by a variety of factors including individual genetic makeup. This is a major component of personalized medicine.

Assistant Professor Deborah Himes (BS ’91) investigates how patients, family members and primary care providers (PCPs) communicate and utilize personalized risk information based on genetic predisposition to various cancers. Genetic predisposition occurs when a mutation of a germ cell, called a germline mutation, is passed down from parent to child. As cancer develops after an individual’s genes go through a series of mutations, individuals who inherit germline mutations require fewer mutations for cancer to develop because they start with genes that are already mutated. This increases their risk level and vulnerability to various cancers.

In addition to increasing the risk level of individuals, germline mutations pose a particular threat to families because multiple siblings can inherit the same mutation. Other factors, such as shared environments and similar lifestyles, also help to explain familial cancer clusters. Himes’s research focuses on women at risk for familial and hereditary breast cancer and (1) how they understand their risk (2) what they communicate about risk within their family and with their PCPs and (3) their screening practices and whether or not those practices are based on specific risk level guidelines.

To perform this study, Himes interviewed 85 women between the ages of 40 and 74 who each had a mother or sister who was diagnosed Capturewith breast cancer. In addition, each sister or mother had received genetic counseling and testing for hereditary breast cancer and an indeterminate negative test result, which means that while no genetic mutations were found, other mutations related to breast cancer that have not yet been discovered or that were not tested could still be present.

To see how women understand their risk level, Himes asked study participants to estimate their individual risk for breast cancer. These results were compared with risk levels calculated using the Gail, Claus, and BRCAPRO models. She found that most participants estimated their own risk to be much higher than what was calculated by the models. This is a concern because overestimation of risk can lead to increased anxiety and the possibility of over-screening. In contrast, accurate risk perception enables women to make informed choices about their healthcare and general well-being.

Himes also conducted a review of communication between family members in relation to genetic counseling and breast cancer. When a woman with breast cancer goes to a genetic counselor, she is told the results of her genetic test and what those results mean, which includes the implications for both herself and her family members. She is then encouraged to share this information with her family members. But Himes found that most family members felt that very little information was communicated with them by their sister or mother. In fact nearly 20 percent of study participants reported that no information was shared with them at all.  Additionally she found that participants who received more information from their sister or mother were twice as accurate in estimating their own risk level.

This study also investigated what information women communicate with their PCP. Because PCPs play an important role in assessing women’s risk for breast cancer and recommending screening tests, it is important that pertinent history information—such as a sister’s or mother’s breast cancer, genetic counseling, and genetic testing—be shared with them. In asking study participants what information they shared with their PCP in relation to breast cancer, Himes found that women are much more likely to share family cancer history than information about an individual family member’s genetic counseling and test results. This is an issue because lack of information has the potential to impair a PCP’s ability to interpret specific risk level and recommend screening tests.

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Finally, Himes looked at screening recommendations and practices and whether or not those recommendations are based on individualized risk levels. Understanding specific risk level is important because various organizations—such as the American Cancer Society (ACS), the National Comprehensive Cancer Network (NCCN), and the American Congress of Obstetricians and Gynecologists (ACOG)—publish recommendations for breast cancer screening based on risk level. For women with an elevated risk for breast cancer (lifetime risk greater than 20 percent), it is recommended they be offered annual screening breast MRIs in addition to mammography.

In her research Himes found that most participants received appropriate mammogram recommendations, whether they were at a high or average risk. However, of the 10 percent of participants who were determined to be high risk, none received or were even offered screening breast MRI; consequently, these women did not go through a more thorough and potentially lifesaving screening for breast cancer.

These findings indicate that there is an increased need for individualized breast-cancer risk assessment and risk-based screening recommendations in primary care.  Effective interventions are needed that will assist patients and PCPs in making informed decisions about screening and prevention measures related to breast cancer. The results of this study also indicate that there is an increased need for communications both within families and among professionals from a variety of disciplines. New interventions and policies may need to be implemented to fulfill this need.

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