Willingness to Test for BRCA1/2 in High Risk Women: Influenced by Risk Perception and Family Experience, Rather Than by Objective Or Subjective Numeracy?
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Dartmouth College Dartmouth Digital Commons Dartmouth Scholarship Faculty Work 7-2015 Willingness to test for BRCA1/2 in High Risk Women: Influenced by Risk Perception and Family Experience, rather than by Objective or Subjective Numeracy? Talya Miron-Shatz Ono Academic College Yaniv Hanoch Plymouth University Benjamin A. Katz , Hebrew University of Jerusalem Glen M. Doniger Ono Academic College Elissa M. Ozanne Dartmouth College Follow this and additional works at: https://digitalcommons.dartmouth.edu/facoa Part of the Medicine and Health Sciences Commons Dartmouth Digital Commons Citation Miron-Shatz, Talya; Hanoch, Yaniv; Katz, Benjamin A.; Doniger, Glen M.; and Ozanne, Elissa M., "Willingness to test for BRCA1/2 in High Risk Women: Influenced yb Risk Perception and Family Experience, rather than by Objective or Subjective Numeracy?" (2015). Dartmouth Scholarship. 3546. https://digitalcommons.dartmouth.edu/facoa/3546 This Article is brought to you for free and open access by the Faculty Work at Dartmouth Digital Commons. It has been accepted for inclusion in Dartmouth Scholarship by an authorized administrator of Dartmouth Digital Commons. For more information, please contact [email protected]. Judgment and Decision Making, Vol. 10, No. 4, July 2015, pp. 386–399 Willingness to test for BRCA1/2 in high risk women: Influenced by risk perception and family experience, rather than by objective or subjective numeracy? Talya Miron-Shatz∗ Yaniv Hanoch † Benjamin A. Katz‡ Glen M. Doniger§ Elissa M. Ozanne¶ Abstract Genetic testing for breast and ovarian cancer can help target prevention programs, and possibly reduce morbidity and mortality. A positive result of BRCA1/2 is a substantial risk factor for breast and ovarian cancer, and its detection often leads to risk reduction interventions such as increased screening, prophylactic mastectomy and oophorectomy. We examined predictors of the decision to undergo cancer related genetic testing: perceived risk, family risk of breast or ovarian cancer, and numeracy as predictors of the decision to test among women at high risk of breast cancer. Stepwise regression analysis of survey responses from 459 women registered in the Cancer Genetics Network revealed greater likelihood to test for women with more family history, higher perceived risk of mutation, or Ashkenazi descent. Neither subjective nor objective numeracy was associated with the decision to test, although we replicated an earlier finding that subjective numeracy predicted willingness to pay for testing. Findings underscore the need for genetic counselling that disentangles risk perception from objective information to promote better decision-making in the context of genetic testing. Highlighting these factors is crucial for public health campaigns, as well as to clinic-based testing and direct-to-consumer testing. Keywords: willingness to test, genetic testing, breast cancer, BRCA1 and 2, subjective numeracy, family history. early detection. 1 Introduction Myriad, 2007). As Direct-to-Consumer (DTC) genetic tests proliferate, the decision of whether to undergo genetic test- Breast cancer is the most prevalent cancer among women ing is often in the individual’s own hands. This was the case (Siegel, Naishadham & Jemal, 2012). For decades, public when we conducted our study. Indeed, the availability of health resources and campaigns have been dedicated to early DTC testing for BRCA in the US has ebbed and flowed in detection and education (Lee et al., 2014) to women in high- the past few years (Food and Drug Administration, 2013). risk groups. The BRCA1 and BRCA2 gene mutations, for ex- With the recent US Supreme Court decision in Association ample, are a known genetic risk factor for the development for Molecular Pathology v. Myriad Genetics, Inc. (2013), of breast and ovarian cancer (Squiers et al., 2010). Their patent rights for the BRCA1/2 genes were revoked, opening detection allows women to be better informed and proactive up the genetic testing market to competition. about future health decisions, and indeed, detection with ge- With the growing accessibility to genetic tests, patients netic testing has become more prevalent (Kolor et al, 2012; might want to test, and still be apprehensive of testing: This research was supported by American Cancer Society Grant No. among 69 patients who participated in semi-structured in- MRSG112037 (EMO), Cancer Genetics Network RFA CA–97-004, RFA terviews on testing, many expressed concerns regarding dis- CA–97-019, RFP No. N01–PC–55049–40, a University of Plymouth crimination, and psychological harm due to the testing re- award (YH), European Research Council Marie Curie Reintegration Grant sults (Gray et al., 2013). Large-scale public health studies No. PIRG7–GA–2010–268224 (TMS), and the Research Authority of the Ono Academic College. The authors wish to thank Dr. David Zucker of the show that testing rates in general tend to be suboptimal (e.g., Hebrew University for invaluable statistical guidance. Schlich-Bakker et al., 2007; Tao, Hooevr & Kent, 2012). Copyright: © 2015. The authors license this article under the terms of the Creative Commons Attribution 3.0 License. In order to encourage testing for the most at-risk, women ∗Center for Medical Decision Making, Ono Academic College, 104 Za- are currently advised to test for the BRCA1/2 gene muta- hal St., Kiryat Ono 55000, Israel. E-mail: [email protected]. tion if a family member has tested positive for it, or if a †School of Psychology, Plymouth University, UK close relative has been diagnosed with cancer (Moyer, 2014; ‡ Department of Psychology, Hebrew University of Jerusalem, Israel. National Cancer Institute, 2013). Guidelines also estab- §Center for Medical Decision Making, Ono Academic College, Israel ¶Dartmouth Institute for Health Policy and Clinical Practice, Geisel lish a standard of care for women who have family mem- School of Medicine at Dartmouth, USA. bers with breast, ovarian, tubal, or peritoneal cancer that 386 Judgment and Decision Making, Vol. 10, No. 4, July 2015 Willingness to test for BRCA1/2 gene mutation 387 call for screening, genetic counselling, and, if appropriate, a role in calculating various statistical estimates, includ- BRCA testing (U.S. Preventive Services Task Force [USP- ing understanding medical risk information (e.g., Hanoch, STF], 2005; Moyer, 2014; National Comprehensive Cancer Miron-Shatz & Himmelstein, 2010; Låg, Bauger, Lindberg Network [NCCN], 2013). In practice, a meta-analysis of 40 & Friborg, 2014 ; Schwartz, Woloshin, Black & Welch, studies revealed that 59% of the women identified by the in- 1997). Assumedly, higher levels of numeracy should be vestigators as high-risk would test. However, testing rates associated with testing rates, so that women at higher risk varied from 25% to 96%, depending on the study (Ropka, for developing breast cancer would be more likely to test, Wenzel, Philips, Siadaty & Philbrick, 2006). Interestingly, and women at a lower risk would be less likely. Accord- some work has shown that family history of breast can- ingly, Lipkus, Peters, Kimmick, Liotcheva and Marcom cer does not predict testing among women with or without (2007) found that more numerate women tended to estimate breast cancer (Bruno et al., 2010). In contrast, earlier inves- more accurately their breast cancer risks, and were signifi- tigations have shown that attitudes, cancer worry, knowl- cantly more open to recommended risk management strate- edge, religious involvement, and risk perception influence gies. Similarly, in a sample of 6,754 adult respondents to women’s decision to undergo genetic testing (Chaliki et al., the National Cancer Institute’s 2007 Health Information Na- 1995; Ruddy et al., 2010). Thus, the decision whether to tional Trends Survey (HINTS), numeracy was found to di- undergo genetic testing is complex (Sankar, Wolpe, Jones & rectly lead to awareness of DTC genetic tests (Lanford, et Cho, 2006). al., 2007). As far as we are aware, the present study is the Perceived risk of breast cancer, or genetic mutations as- first to directly examine whether high numeracy informs the sociated with it may also predict decisions related to testing decision to test. for BRCA1/2. Prior work has found women who perceive Numeracy can be measured through objective, be- themselves to be at greater risk of developing the disease to havioural tests and subjective, self-report questionnaires. be more likely to test for BRCA1/2, and at a higher price Objective numeracy scales examine comprehension of fre- (Chaliki et al., 1995; Ruddy et al., 2010). Further, women quency, probability and percentages (Schwartz et al., 1997; at increased risk for breast cancer show significantly higher Lipkus, Samsa & Rimer, 2001). In contrast, the subjective levels of cancer-specific distress (but not general distress) numeracy scale (SNS, Fagerlin et al., 2007) measures per- relative to a comparison group (Rees, Fry, Cull & Sutton, ceived ability to perform various mathematical operations 2004). and preference for the use of numeric rather than textual Likelihood to test increases as cancer becomes less of a information (Lipkus et al., 2007). SNS can differentiate theoretical concern, and more of a concrete fear. Women among people with objectively low and high numeracy skills 40 years old or younger diagnosed with breast cancer are across different demographic groups: it is quicker to admin- more likely to have undergone genetic testing if they have ister and provides a more agreeable