Primary care physicians' concerns about offering a genetic test to tailor smoking cessation treatment

Genomic medicine to reduce tobacco and related disorders: Translation to precision prevention and treatment

Genomic medicine can enhance prevention and treatment. First, we propose that advances in genomics have the potential to enhance assessment of disease risk, improve prognostic predictions, and guide treatment development and application. Clinical implementation of polygenic risk scores (PRSs) has emerged as an area of active research. The pathway from genomic discovery to implementation is an iterative process. Second, we provide examples on how genomic medicine has the potential to solve problems in prevention and treatment using two examples: Lung cancer screening and evidence-based tobacco treatment are both under-utilized and great opportunities for genomic interventions. Third, we discuss the translational process for developing genomic interventions from evidence to implementation by presenting a model to evaluate genomic evidence for clinical implementation, mechanisms of genomic interventions, and patient desire for genomic interventions. Fourth, we present potential challenges in genomic interventions including a great need for evidence in all diverse populations, little evidence on treatment algorithms, challenges in accommodating a dynamic evidence base, and implementation challenges in real world clinical settings. Finally, we conclude that research to identify genomic markers that are associated with smoking cessation success and the efficacy of smoking cessation treatments is needed to empower people of all diverse ancestry. Importantly, genomic data can be used to help identify patients with elevated risk for nicotine addiction, difficulty quitting smoking, favorable response to specific pharmacotherapy, and tobacco-related health problems.

The Use of the Nicotine Metabolite Ratio as a Biomarker to Personalize Smoking Cessation Treatment: Current Evidence and Future Directions

The nicotine metabolite ratio (NMR), a genetically informed biomarker of rate of nicotine metabolism, has been validated as a tool to select the optimal treatment for individual smokers, thereby improving treatment outcomes. This review summarizes the evidence supporting the development of the NMR as a biomarker of individual differences in nicotine metabolism, the relationship between the NMR and smoking behavior, the clinical utility of using the NMR to personalize treatments for smoking cessation, and the potential mechanisms that underlie the relationship between NMR and smoking cessation. We conclude with a call for additional research necessary to determine the ultimate benefits of using the NMR to personalize treatments for smoking cessation. These future directions include measurement and other methodologic considerations, disseminating this approach to at-risk subpopulations, expanding the NMR to evaluate its efficacy in predicting treatment responses to e-cigarettes and other noncigarette forms of nicotine, and implementation science including cost-effectiveness analyses.See all articles in this Special Collection Honoring Paul F. Engstrom, MD, Champion of Cancer Prevention.

Precision Medicine for Tobacco Dependence: Development and Validation of the Nicotine Metabolite Ratio

Quitting smoking significantly reduces the risk of tobacco-related morbidity and mortality, yet there is a high rate of relapse amongst smokers who try to quit. Phenotypic biomarkers have the potential to improve smoking cessation outcomes by identifying the best available treatment for an individual smoker. In this review, we introduce the nicotine metabolite ratio (NMR) as a reliable and stable phenotypic measure of nicotine metabolism that can guide smoking cessation treatment among smokers who wish to quit. We address how the NMR accounts for sources of variation in nicotine metabolism including genotype and other biological and environmental factors such as estrogen levels, alcohol use, body mass index, or menthol exposure. Then, we highlight clinical trials that validate the NMR as a biomarker to predict therapeutic response to different pharmacotherapies for smoking cessation. Current evidence supports the use of nicotine replacement therapy for slow metabolizers, and non-nicotine treatments such as varenicline for normal metabolizers. Finally, we discuss future research directions to elucidate mechanisms underlying NMR associations with treatment response, and facilitate the implementation of the NMR as biomarker in clinical practice to guide smoking cessation.

'Someday it will be the norm': physician perspectives on the utility of genome sequencing for patient care in the MedSeq Project

AIM

To describe practicing physicians' perceived clinical utility of genome sequencing.

MATERIALS & METHODS

We conducted a mixed-methods analysis of data from 18 primary care physicians and cardiologists in a study of the clinical integration of whole-genome sequencing. Physicians underwent brief genomics continuing medical education before completing surveys and semi-structured interviews.

RESULTS

Physicians described sequencing as currently lacking clinical utility because of its uncertain interpretation and limited impact on clinical decision-making, but they expressed the idea that its clinical integration was inevitable. Potential clinical uses for sequencing included complementing other clinical information, risk stratification, motivating patient behavior change and pharmacogenetics.

CONCLUSION

Physicians given genomics continuing medical education use the language of both evidence-based and personalized medicine in describing the utility of genome-wide testing in patient care.

Bumps along the translational pathway: anticipating uptake of tailored smoking cessation treatment

AIM

To assess potential barriers to clinical integration of tailored smoking cessation treatment among African American and white smokers in the USA.

METHODS

A total of 392 smokers (203 white and 189 African American) identified within a national random digit dial survey (response rate: 40.1%; 81.2% among households with whom we were able to make contact) of 1200 African Americans and 1200 white Americans. Respondents answered several closed-ended survey items addressing beliefs regarding what influences a smoker's ability to quit, past pharmacotherapy use, and their willingness to undergo genetic assessment in order to be matched to optimal treatment, among other items.

RESULTS

In this first nationally representative survey of US smokers, 77% of respondents expressed willingness to undergo genetic testing in order to be matched to optimal pharmacotherapy, yet only 18% had ever used pharmacotherapy in a previous quit attempt. Smokers who rated 'medications and counseling' as very important in quitting were significantly more likely to endorse genetic testing (odds ratio [OR]: 8.94; 95% CI: 1.86-43.06), while those rating 'having God's help' as very important were significantly less likely to express willingness to undergo testing (OR: 0.11; 95% CI: 0.02-0.71). African American smokers were more likely than white smokers to express willingness to undergo genetic testing (OR: 3.80; 95% CI: 1.09-13.22), despite lower rates of previous pharmacotherapy use.

CONCLUSION

While smokers reported high rates of willingness to undergo genetic testing to be matched to optimal treatment, these results suggest that smokers' willingness to use medications indicated by genetic test results may prove a significant barrier to realizing the promise of tailored smoking cessation treatment. The role of spirituality in smokers' willingness to use medication is an area for further study.

Direct-to-consumer personal genome testing and cancer risk prediction

The last several years has witnessed an explosion in genomics, with the advent of genome-wide association studies revealing hundreds of DNA variants significantly associated with most common diseases, including cancer. On the heels of these scientific advances came the direct-to-consumer (DTC) genetic testing industry. Genome-wide scans for disease have been marketed and sold directly to the public, without the involvement of a health care provider. Unlike genetic testing for mutations in known hereditary cancer susceptibility genes such as BRCA1/2, these genomic profiles examine DNA variants, which typically have a minimal risk impact, and account for only a fraction of the heritable component of cancer. Furthermore, risk information provided to consumers does not account for family history or other known risk factors. The clinical validity and utility of personal genome scans for disease risk prediction remain for the most part unestablished, although some argue lack of evidence of harm and the possibility that positive impacts on health behaviors or genetic awareness may result from consumer use. The DTC genetic testing industry has sparked significant controversy not only among the scientific community, but also among professional societies and government agencies.In this review, we present some of the history and methodological considerations of DTC genomic profiling, with a focus on cancer risk prediction. The literature regarding consumer awareness and utilization is explored, including understanding, expectations, and behavioral and psychological responses to DTC genomic risk prediction. Primary care provider and genetic professional knowledge and perceptions of DTC genomic profiling are also addressed. Ethical and scientific controversy surrounding the DTC genetic testing industry is presented, along with policy recommendations, regulatory actions, and the changing landscape of the DTC genetic testing market in response. Although our understanding of the human genome holds much promise in the realm of cancer prevention and treatment, DTC genomic profiling for cancer risk prediction is unlikely in its current form to have any significant impact on the health of the public. Time will tell if the next venture in genomic medicine, whole genome sequencing, will be accompanied by the translational research and emphasis on public/provider education required to ensure its successful application toward reducing the burden of cancer at a population level.

Biomarkers to optimize the treatment of nicotine dependence

The application of genomic medicine to the treatment of nicotine dependence holds great promise for revitalizing the steady decline in smoking rates witnessed in the USA over the past several decades. This paper examines the current knowledge base concerning the use of biomarkers to guide the selection of nicotine dependence treatments. First, we review the neurobiology of nicotine dependence and present evidence that supports its heritability. We then discuss the various studies of pharmacokinetic and pharmacodynamic genes related to therapeutic response. Current evidence suggests that biomarkers of genetic variability in both nicotine metabolism, referred to as the nicotine metabolite ratio, and dopamine genotypes may be useful for guiding treatment selection for nicotine dependence. Barriers to the translation of this research to clinical practice are discussed, as are directions for future research.

Public attitudes toward ancillary information revealed by pharmacogenetic testing under limited information conditions

PURPOSE

Pharmacogenetic testing can inform drug dosing and selection by aiding in estimating a patient's genetic risk of adverse response and/or failure to respond. Some pharmacogenetic tests may generate ancillary clinical information unrelated to the drug treatment question for which testing is done-an informational "side effect." We aimed to assess public interest and concerns about pharmacogenetic tests and ancillary information.

METHODS

We conducted a random-digit-dial phone survey of a sample of the US public.

RESULTS

We achieved an overall response rate of 42% (n = 1139). When the potential for ancillary information was presented, 85% (±2.82%) of respondents expressed interest in pharmacogenetic testing, compared with 82% (±3.02%) before discussion of ancillary information. Most respondents (89% ± 2.27%) indicated that physicians should inform patients that a pharmacogenetic test may reveal ancillary risk information before testing is ordered. Respondents' interest in actually learning of the ancillary risk finding significantly differed based on disease severity, availability of an intervention, and test validity, even after adjusting for age, gender, education, and race.

CONCLUSION

Under the limited information conditions presented in the survey, the potential of ancillary information does not negatively impact public interest in pharmacogenetic testing. Interest in learning ancillary information is well aligned with the public's desire to be informed about potential benefits and risks before testing, promoting patient autonomy.

Genomic risk profiling: attitudes and use in personal and clinical care of primary care physicians who offer risk profiling

BACKGROUND

Genomic risk profiling involves the analysis of genetic variations linked through statistical associations to a range of disease states. There is considerable controversy as to how, and even whether, to incorporate these tests into routine medical care.

OBJECTIVE

To assess physician attitudes and uptake of genomic risk profiling among an 'early adopter' practice group.

DESIGN

We surveyed members of MDVIP, a national group of primary care physicians (PCPs), currently offering genomic risk profiling as part of their practice.

POPULATION

All physicians in the MDVIP network (N = 356)

RESULTS

We obtained a 44% response rate. One third of respondents had ordered a test for themselves and 42% for a patient. The odds of having ordered personal testing were 10.51-fold higher for those who felt well-informed about genomic risk testing (p < 0.0001). Of those who had not ordered a test for themselves, 60% expressed concerns for patients regarding discrimination by life and long-term/disability insurers, 61% about test cost, and 62% about clinical utility. The odds of ordering testing for their patients was 8.29-fold higher among respondents who had ordered testing for themselves (p < 0.0001). Of those who had ordered testing for patients, concerns about insurance coverage (p = 0.014) and uncertain clinical utility (p = 0.034) were associated with a lower relative frequency of intention to order testing again in the future.

CONCLUSIONS

Our findings demonstrate that respondent familiarity was a key predictor of physician ordering behavior and clinical utility was a primary concern for genomic risk profiling. Educational and interpretive support may enhance uptake of genomic risk profiling.

Professional perspectives about pharmacogenetic testing and managing ancillary findings

AIMS

Pharmacogenetic (PGx) tests, intended to inform therapeutic decision making through prediction of patient likelihood to respond to or experience an adverse effect from a specific treatment, may also generate ancillary, or incidental, disease information unrelated to the purpose for which the test was ordered. To assess attitudes toward PGx testing, ancillary disease risk information, and related clinical issues, we conducted a series of focus groups among health professionals.

RESULTS

Twenty-one primary care and genetics professionals from Durham, NC, were recruited to participate in three focus groups (two of primary care professionals [PCPs] and one of geneticists). Overall, interest in PGx testing was positive, though enthusiasm was reserved among PCPs due to concerns about clinical utility, insurance coverage, delay of treatment, and ability to communicate and interpret ancillary disease risk information. Although many PCPs felt an obligation to disclose information about ancillary disease risk, geneticists did not believe that it was always necessary, noting the complexities of genetic risk results such as incomplete penetrance.

CONCLUSION

This pilot study found that health professionals' interest in the use of PGx testing was limited by concerns about the lack of evidence of clinical utility and their ability to interpret and communicate ancillary disease risk information to patients. Additional educational resources, access to genetic specialists, and clear clinical guidelines about the use of PGx testing would greatly facilitate appropriate use of testing.

Physician barriers to incorporating pharmacogenetic treatment strategies for nicotine dependence into clinical practice

Advances in genomics research may improve health outcomes by tailoring treatment according to patients' genetic profiles. The treatment of nicotine dependence, in particular, may soon encompass pharmacogenetic treatment models. Realizing the benefits of such treatment strategies may depend on physicians' preparedness to incorporate genetic testing into clinical practice. This article describes barriers to clinical integration of pharmacogenetic treatments that will need to be addressed to realize the benefits of individualized smoking-cessation treatment.

Adolescent medical providers' willingness to recommend genetic susceptibility testing for nicotine addiction and lung cancer risk to adolescents

OBJECTIVE

To examine the influences of disease, lifestyle, and other factors on adolescent medical providers' willingness to recommend genetic susceptibility testing (GST).

METHOD

Providers attending a national conference completed a self-report survey (n = 232) about their willingness to recommend hypothetical GSTs, differentiated by disease (nicotine addiction/lung cancer), patient lifestyle (nonsmoker/smoker), and other contextual factors.

RESULTS

Compared to recommending GST unconditionally, providers were more willing to recommend GST with parental/patient consent/assent, and in the presence of a preexisting illness and substance abuse history. Compared to offering nicotine addiction GST to a nonsmoker, providers were more willing to offer this type of testing to a smoker and were more willing to offer GST for lung cancer regardless of patient lifestyle.

CONCLUSIONS

Providers' willingness to recommend GSTs is sensitive to many factors. Efforts to integrate GST into adolescent preventive care likely will need to address these and other influences on provider behavior.

Anticipating clinical integration of pharmacogenetic treatment strategies for addiction: are primary care physicians ready?

Emerging pharmacogenomics research on addiction to nicotine, alcohol, cocaine, and opiates may soon lead to improved clinical outcomes by tailoring the type, dose and duration of treatment to individual patients' genotypes. To realize the potential of pharmacogenomics in reducing the burden of addiction, several challenges related to clinical integration of novel treatment strategies will need to be addressed concomitantly with ongoing empirical research. These challenges include the preparedness of primary care physicians (PCPs) to incorporate pharmacogenetics into clinical practice, patients' willingness to undergo genetic testing, the resources and infrastructure needed to deliver such services, adequate financing and reimbursement of pharmacogenetic testing, and privacy and antidiscrimination protections sufficient to reassure physicians and patients that genetic testing will not lead to stigmatization and discrimination.