Biomarkers for smoking cessation

One way to enhance therapeutic development is through the identification and development of evaluative tools such as biomarkers. This review focuses on putative diagnostic, pharmacodynamic, and predictive biomarkers for smoking cessation. These types of biomarkers may be used to more accurately diagnose a disease, personalize treatment, identify novel targets for drug discovery, and enhance the efficiency of drug development. Promising biomarkers are presented across a range of approaches including metabolism, genetics, and neuroimaging. A preclinical viewpoint is also offered, as are analytical considerations and a regulatory perspective summarizing a pathway toward biomarker qualification.

APOE ɛ4, an Alzheimer's disease susceptibility allele, and smoking cessation

Possessing an apolipoprotein E (APOE) ɛ4 allele, advanced age and smoking are risk factors for Alzheimer's disease and cognitive decline. Deficits in cognitive function also increase risk for smoking relapse. Data from 917 adult smokers of European ancestry were pooled across three randomized trials of smoking cessation. We examined whether smokers who carry at least one ɛ4 allele (n=252) have more difficulty quitting smoking compared with noncarriers (n=665), and whether age moderated this association. The genotype by age interaction was significant for 7-day point-prevalence abstinence rates (P=0.04) and time to 7-day failure (P=0.03). Among smokers over age 60, ɛ4 carriers were less likely to quit (odds ratio=0.27, P=0.018) and relapsed more quickly (hazard ratio=3.38, P=0.001) compared with noncarriers. The genotype association with relapse was nonsignificant among younger smokers. An increased understanding of the underlying pathophysiological mechanisms of this association could facilitate the development of targeted therapies for smokers with increased risk for cognitive decline.

Association of BDNF and COMT genotypes with cognitive processing of anti-smoking PSAs

Anti-smoking public service announcements (PSAs) often use persuasive arguments to attempt to influence attitudes about smoking. The persuasiveness of a PSA has previously been associated with factors that influence the cognitive processing of its message. Genetic factors that influence cognitive processing might thus affect individuals' responses to the persuasive arguments presented in PSAs. In the present study, we examined polymorphisms in the genes encoding brain-derived neurotrophic factor (BDNF Val66Met) and catechol-O-methyltransferase (COMT Val158Met), which affect cognitive processing in the prefrontal cortex, to identify genetic factors associated with self-reported outcomes of message processing, perceived effectiveness and quitting intentions among smokers viewing PSAs. A total of 120 smokers viewed sets of four PSAs that varied with respect to features of argument strength (AS) and message sensation value. We observed significant associations of BDNF genotype with central processing, narrative processing, perceived effectiveness of the anti-smoking PSAs and participant quitting intentions; the BDNF Met allele was associated with lower scores on all these measures. Central processing acted as a mediator of the association of genotype with quitting intentions and perceived effectiveness. There was a significant interaction of COMT genotype by AS in the model of narrative processing, such that individuals homozygous for the COMT Val allele reported higher narrative processing in the high-AS condition but not in the low-AS condition. To our knowledge, this is the first study to identify genetic factors associated with cognitive processing of anti-smoking PSAs.

Gender-stratified gene and gene-treatment interactions in smoking cessation

We conducted gender-stratified analyses on a systems-based candidate gene study of 53 regions involved in nicotinic response and the brain-reward pathway in two randomized clinical trials of smoking cessation treatments (placebo, bupropion, transdermal and nasal spray nicotine replacement therapy). We adjusted P-values for multiple correlated tests, and used a Bonferroni-corrected α-level of 5 × 10(-4) to determine system-wide significance. Four single-nucleotide polymorphisms (rs12021667, rs12027267, rs6702335, rs12039988; r2 > 0.98) in erythrocyte membrane protein band 4.1 (EPB41) had a significant male-specific marginal association with smoking abstinence (odds ratio (OR) = 0.5; 95% confidence interval (CI): 0.3-0.6) at end of treatment (adjusted P < 6 × 10(-5)). rs806365 in cannabinoid receptor 1 (CNR1) had a significant male-specific gene-treatment interaction at 6-month follow-up (adjusted P = 3.9 × 10(-5)); within males using nasal spray, rs806365 was associated with a decrease in odds of abstinence (OR = 0.04; 95% CI: 0.01-0.2). While the role of CNR1 in substance abuse has been well studied, we report EPB41 for the first time in the nicotine literature.

Effect of abstinence challenge on brain function and cognition in smokers differs by COMT genotype

The val allele of the catechol-O-methyltransferase (COMT) val(158)met polymorphism has been linked with nicotine dependence and with cognitive performance in healthy volunteers. We tested the hypothesis that the val allele is a risk factor for altered brain function and cognition during nicotine abstinence as compared with the normal smoking state. Chronic smokers (n=33) were genotyped prospectively for the COMT polymorphism for balanced selection of met/met, val/met and val/val groups. A visual N-back working memory task was performed during two separate blood oxygen level-dependent (BOLD) functional magnetic resonance imaging sessions in counterbalanced order: (1) smoking as usual, and (2)>or=14 h confirmed abstinence. Significant genotype by session interactions were observed for BOLD signal in right dorsolateral prefrontal cortex (DLPFC; (P=0.0005), left DLPFC (P=0.02) and dorsal cingulate/medial prefrontal cortex (P=0.01) as well as for task reaction time (P=0.03). Smokers with val/val genotypes were more sensitive to the abstinence challenge than carriers of the met allele, with the greatest effects on BOLD signal and performance speed at the highest working memory load. These data suggest a novel brain-behavior mechanism that may underlie the increased susceptibility to nicotine dependence and smoking relapse associated with the COMT val allele. Exploration of the effects of COMT inhibitors as a possible smoking cessation aid in this group may be warranted.

Effects of atomoxetine on subjective and neurocognitive symptoms of nicotine abstinence

Nicotine dependence has been linked to attention-deficit hyperactivity disorder (ADHD) symptoms in both clinical and general populations. This behavioural pharmacology study used a within-subject, double-blind, crossover design to test the effects of atomoxetine, a medication for ADHD, on nicotine abstinence symptoms. Fifty non treatment-seeking smokers (>/=15 cigarettes/day) completed a baseline session when they were smoking as usual and then two laboratory testing sessions after overnight abstinence and treatment with 7 days of either atomoxetine (1.2 mg/kg) or placebo. During each laboratory session, participants completed subjective measures of abstinence symptoms and performed neurocognitive tasks. In mixed effects models, atomoxetine, compared with placebo, was found to be associated with a reduction in abstinence-induced subjective withdrawal symptoms. Atomoxetine was also associated with significant reductions in self-reported smoking urges amongst smokers who scored high on a baseline measure of smoking for stimulation. However, atomoxetine had no effect on any of the cognitive tasks employed in the study. Thus, atomoxetine may reduce cravings to smoke among smokers who use nicotine to increase arousal.

Snus use and other correlates of smoking cessation in the Swedish Twin Registry

BACKGROUND

We investigated 12 variables and their interactions as correlates of smoking cessation among regular smokers in the population-based Swedish Twin Registry (STR).

METHOD

Detailed information on tobacco use and personal characteristics were available from 14 715 male and female twins aged 42-64 years who participated in a screening of the population-based STR and reported being regular smokers in their lifetime. A two-stage analytic design was used to examine correlates of smoking cessation. The sample was split at random and significant main effects and interactions identified in the testing set were examined in the validation set. Hazard ratios (HRs) and 95% confidence intervals (CIs) describe the association between correlates and smoking cessation.

RESULTS

Twelve main effects were significantly associated with smoking cessation in the testing set; eight were confirmed in the validation set. Of the nine interactions identified in the testing set, none remained significant when evaluated in the validation set after Bonferroni correction. HRs were highest for Swedish oral smokeless tobacco (snus) use (HR 2.70, 95% CI 2.30-3.20), >11 years of education (HR 1.57, 95% CI 1.43-1.73) and being married or cohabitating (HR 1.51, 95% CI 1.39-1.63). Although not statistically significant after Bonferroni correction, snus use also appeared important in the context of interactions, where lower nicotine dependence score, higher socio-economic status (SES) and greater body size were associated with smoking cessation only among participants who never used snus.

CONCLUSIONS

Snus use was the strongest independent correlate of smoking cessation. Further studies should investigate the mechanism of this association.

Cost-effectiveness of pharmacogenetic testing to tailor smoking-cessation treatment

We evaluated the cost-effectiveness of a range of smoking cessation drug treatments, including varenicline, transdermal nicotine (TN), bupropion and the use of a genetic test to choose between TN and bupropion. We performed Monte Carlo simulation with sensitivity analysis, informing analyses with published estimates of model parameters and current prices for genetic testing and smoking-cessation therapy. The primary outcomes were discounted life-years (LY) and lifetime tobacco-cessation treatment costs. In the base case, varenicline treatment was optimal with an ICER, compared to bupropion, of $2985/LY saved. In sensitivity analyses, varenicline was in all cases (and bupropion in most cases) admissible; only under favorable assumptions was the genetically tailored approach competitive. Our data suggest that an untailored approach of treatment with either bupropion or varenicline is a cost-effective form of tobacco dependence treatment, but a tailored approach for selecting between TN and bupropion can be cost-effective under plausible assumptions.

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.

Association of OPRM1 A118G variant with the relative reinforcing value of nicotine

RATIONALE

The endogenous opioid system has been implicated in substance abuse and response to pharmacotherapies for nicotine and alcohol addiction. We examined (1) the association of the functional OPRM1 A118G variant with the relative reinforcing value of nicotine and (2) the main and interacting effects of the mu-opioid receptor antagonist naltrexone on nicotine reinforcement.

METHODS

In a within-subject, double-blind human laboratory study, 30 smokers of each OPRM1 genotype (A/A vs. A/G or G/G) participated in two experimental sessions following 4 days of orally administered naltrexone 50 mg or placebo. Participants completed a validated assessment of the relative reinforcing value of nicotine. This cigarette choice paradigm assesses self-administration of 0.6 mg nicotine vs. 0.05 mg (denicotinized) cigarettes after a brief period of nicotine abstinence.

RESULTS

The relative reinforcing value of nicotine (number of nicotine cigarette puffs) was predicted by a significant OPRM1 by gender interaction. Among women, the low-activity G allele (A/G and G/G) was associated with a reduced reinforcing value of nicotine; among male smokers, there was no association with genotype. Smokers carrying a G allele were also significantly less likely to differentiate the nicotine vs. denicotinized cigarettes by subjective ratings of satisfaction and strength. No evidence for an effect of naltrexone on nicotine reinforcement was found in the overall sample or in the genotype or gender subgroups.

CONCLUSIONS

This study provides initial evidence for an association of the OPRM1 A118G variant with nicotine reinforcement in women.

Impact of CYP2A6 genotype on pretreatment smoking behaviour and nicotine levels from and usage of nicotine replacement therapy

We investigated the effect of slow metabolism of nicotine, predicted by CYP2A6 genotypes resulting in less than or equal to 50% activity, on baseline smoking behaviours and treatment variables in an open-label nicotine replacement therapy (NRT) clinical trial. Caucasian smokers with CYP2A6 slow vs normal metabolism had lower metabolic activity, indicated by the 3-hydroxycotinine/cotinine ratio (0.23+/-0.17 vs 0.45+/-0.22, P<0.01, respectively). CYP2A6 slow metabolizers also smoked fewer cigarettes per day compared to normal metabolizers (20+/-7 vs 24+/-10, respectively, P<0.04). With nicotine patch use, slow metabolizers had higher nicotine plasma levels compared to normal metabolizers (22.8+/-4.6 vs 15.8+/-7.6 ng/ml, respectively, P=0.02) while using the same numbers of patches/week. With nicotine spray use, where like in smoking the nicotine intake can be easily adjusted to adapt to rates of metabolism, slow metabolizers achieved similar nicotine levels compared to normal metabolizers (5.8+/-4.1 vs 8.0+/-9.1 ng/ml, P=0.82), by using fewer doses of nicotine spray/day (4.8+/-3.6 vs 10.5+/-8.0, respectively, P<0.02). These findings indicate that CYP2A6 genotype influences smoking behaviour in a Caucasian treatment-seeking population and that CYP2A6 genotype affects plasma levels obtained from, and usage of, NRT.

Is Swedish snus associated with smoking initiation or smoking cessation?

Nicotine replacement therapies (NRT) are an effective treatment for tobacco dependence, yet most smokers do not quit or remain abstinent. We investigated whether Swedish snus (snuff) use was associated with smoking cessation among males participating in a large population based twin study in Sweden. Snus use was associated with smoking cessation but not initiation. Given that snus delivers comparable nicotine concentrations but carries lesser cancer risk than cigarettes, snus may be a widely used, non-medical form of NRT. Evaluation of the efficacy of snus for smoking cessation should be evaluated in randomised clinical trials.

Interaction between variation in the D2 dopamine receptor (DRD2) and the neuronal calcium sensor-1 (FREQ) genes in predicting response to nicotine replacement therapy for tobacco dependence

We have previously demonstrated that a functional dopamine D2 receptor promoter variant (DRD2 -141 Ins/Del) predicts response to nicotine replacement therapy (NRT). The present study extends this finding in the same population of 363 NRT-treated subjects, by examining variation in the gene encoding the neuronal calcium sensor-1 protein (FREQ), which functions to regulate D2 receptor desensitization. The results indicate a statistically significant interaction effect of DRD2-141 and FREQ genotypes on abstinence at the end of the NRT treatment phase; 62% of the smokers with at least one copy of the DRD2 -141 Del allele and two copies of the FREQ rs1054879 A allele were abstinent from smoking, compared to 29-38% abstinence rates for other smokers in the trial. This result suggests that the interaction between variation in the DRD2 and FREQ genes, which both encode components of the D2 dopamine receptor signal transduction pathway, impacts the efficacy of NRT.

Effects of dopamine D2 receptor (DRD2) and transporter (SLC6A3) polymorphisms on smoking cue-induced cigarette craving among African-American smokers

Cue-induced craving for addictive substances has long been known to contribute to the problem of persistent addiction in humans. Research in animals over the past decade has solidly established the central role of dopamine in cue-induced craving for addictive substances, including nicotine. Analogous studies in humans, however, are lacking, especially among African-American smokers, who have lower quit rates than Caucasian smokers. Based on the animal literature, the study's objective was to test the hypothesis that smokers carrying specific variants in dopamine-related genes previously associated with risk for addictive behaviors would exhibit heightened levels of cigarette craving following laboratory exposure to cues. To this end, cigarette craving was induced in healthy African-American smokers (n=88) through laboratory exposure to smoking cues. Smokers carrying either the DRD2 (D2 dopamine receptor gene) TaqI A1 RFLP or the SLC6A3 (dopamine transporter gene) 9-repeat VNTR polymorphisms had stronger cue-induced cravings than noncarriers (Ps <0.05 and 0.01, respectively). Consistent with the separate biological pathways involved (receptor, transporter), carriers of both polymorphisms had markedly higher craving responses compared to those with neither (P<0.0006), reflecting additive effects. Findings provide support for the role of dopamine in cue-induced craving in humans, and suggest a possible genetic risk factor for persistent smoking behavior in African-American smokers.

Monoamine reuptake inhibition and nicotine receptor antagonism reduce amplitude and gating of auditory evoked potentials

BACKGROUND

Sensory encoding deficits have been extensively studied as endophenotypic markers of schizophrenia using auditory evoked potentials. In order to increase understanding of the neurochemical basis of such deficits, we utilized an animal model to test whether monoamine reuptake inhibition and nicotine receptor antagonism reduce the amplitude and gating of the P20 and N40 auditory components.

METHODS

C57BL/6J mice received 12 days of chronic vehicle, bupropion, haloperidol or bupropion plus haloperidol. Auditory evoked potentials were then recorded in alert mice to measure the amplitude and gating of evoked components during a paired click paradigm similar to tasks used to measure the P50 and N100 auditory potentials in schizophrenia. Evoked potentials were recorded prior to and following acute nicotine.

RESULTS

Bupropion reduced the amplitude and gating of the N40 evoked potential in mice, similar to the P50 and N100 endophenotypes associated with sensory encoding deficits in schizophrenia. This deficit was fully reversed only by the combination of haloperidol and nicotine, suggesting that dopamine reuptake inhibition and nicotine antagonism both contribute to the observed phenotype. Furthermore, nicotine increased P20 amplitude across all groups supporting a role for nicotine agonists in pre-attentive sensory encoding deficits.

CONCLUSIONS

We propose that the combination of monoamine inhibition and nicotine receptor antagonism may serve as a useful model for preclinical screening of pharmaceutical compounds aimed at treating sensory encoding deficits in schizophrenia.

Stress-induced cigarette craving: effects of the DRD2 TaqI RFLP and SLC6A3 VNTR polymorphisms

Animal models have long implicated dopamine in stress-induced craving for a variety of addictive substances. However, translational studies of dopamine, stress and craving in humans are lacking. Based on the animal literature, this study's objective was to test the hypothesis that cigarette smokers carrying specific variants in dopamine-related genes would have heightened levels of cigarette craving following exposure to a laboratory stressor. Cigarette craving induced by controlled exposure to a laboratory stressor was assessed in healthy adult smokers (n=108) recruited by advertisement. Significantly stronger stress-induced cigarette craving was found for individuals carrying either the DRD2 (D2 dopamine receptor gene) A1, or the SLC6A3 (dopamine transporter gene) nine-repeat allelic variants. Stress-induced craving was markedly higher for those carrying both alleles, compared to those with neither, consistent with the separate biological pathways involved (receptor, transporter). Findings provide strong support for the possibility that dopamine involvement in stress-induced craving well established in animal models also applies to humans, and suggest a potential genetic risk factor for persistent smoking behavior.

The functional mu opioid receptor (OPRM1) Asn40Asp variant predicts short-term response to nicotine replacement therapy in a clinical trial

To determine whether the functional mu-opioid receptor (OPRM1) Asn40Asp variant predicts the comparative efficacy of different forms of NRT, we conducted a clinical trial of transdermal nicotine (TN) vs nicotine nasal spray (NS) in 320 smokers of European ancestry. Smokers carrying the OPRM1 Asp40 variant (n=82) were significantly more likely than those homozygous for the Asn40 variant (n=238) to be abstinent at the end of treatment, and reported less mood disturbance and weight gain. The genotype effect on treatment outcome was most pronounced among smokers receiving TN, particularly during the 21 mg dose phase. Smokers who carry the OPRM1 Asp40 variant are likely to have a favorable response to TN and may benefit from extended therapy with the 21 mg dose.

Attention-Deficit Hyperactivity Disorder (ADHD) symptoms and smoking patterns among participants in a smoking-cessation program

Previous research has suggested an increased liability to smoking among individuals with Attention-Deficit Hyperactivity Disorder (ADHD). This link is thought to be attributable, in part, to nicotine's beneficial effects on attention and performance. In the present study, we examined the association of ADHD symptoms of inattention and hyperactivity with smoking behavior in a sample of 226 male and female smokers ages 18 and older who were enrolled in a smoking-cessation program. Prior to treatment, they completed measures of ADHD symptoms and standardized measures of smoking patterns. Hierarchical linear regression models were used to characterize the smoking patterns associated with ADHD inattention and hyperactivity symptoms, controlling for potential confounder variables. Smoking for stimulation purposes and the urge to smoke to minimize withdrawal symptoms were the primary patterns associated with ADHD inattention symptoms, while hyperactivity symptoms were not associated with smoking patterns. Consistent with a self-medication hypothesis, these results suggest that smokers with frequent symptoms of inattention may use nicotine as a stimulant drug to help manage these symptoms. Future studies of the role of inattention symptoms in response to smoking treatment are warranted.

Progesterone receptor variant increases ovarian cancer risk in BRCA1 and BRCA2 mutation carriers who were never exposed to oral contraceptives

Oral contraceptives have been shown to be protective against hereditary ovarian cancer. The variant progesterone receptor allele named PROGINS is characterized by an Alu insertion into intron G and two additional mutations in exons 4 and 5. The PROGINS allele codes for a progesterone receptor with increased stability and increased hormone-induced transcriptional activity. We studied the role of the PROGINS allele as a modifying gene in hereditary breast and ovarian cancer. The study included 195 BRCA1 and BRCA2 carriers with a prior diagnosis of ovarian cancer, 392 carriers with a diagnosis of breast cancer and 249 carriers with neither cancer. Fifty-eight women had both forms of cancer. Five hundred and ninety-five women had a BRCA1 mutation and 183 women had a BRCA2 mutation. Overall, there was no association between disease status and the presence of the PROGINS allele. Information on oral contraception use was available for 663 of the 778 carriers of BRCA1 or BRCA2 mutations. Among the 449 subjects with a history of oral contraceptive use (74 cases and 365 controls), no modifying effect of PROGINS was observed [odds ratio (OR) 0.8; 95% confidence interval (CI) 0.5-1.3]. Among the 214 carriers with no past exposure to oral contraceptives, the presence of one or more PROGINS alleles was associated with an OR of 2.4 for ovarian cancer, compared to women without ovarian cancer and with no PROGINS allele (P = 0.004; 95% CI 1.4-4.3). The association was present after adjustment for ethnic group and for year of birth.

Impact of educational print materials on knowledge, attitudes, and interest in BRCA1/BRCA2: testing among Ashkenazi Jewish women

BACKGROUND

The recent identification of several BRCA1/BRCA2 founder mutations among Ashkenazi Jewish individuals has led to increased salience of BRCA1/BRCA2 testing for Jewish individuals. Little is known about interest in BRCA1/BRCA2 testing among Ashkenazi Jews from the general population. Furthermore, previous research has not generally evaluated the impact of education on interest in testing among individuals from the general population. The goal of the current study was to examine whether a brief educational booklet regarding BRCA1/BRCA2 testing would influence knowledge, attitudes, and interest in testing among Ashkenazi Jewish women from the general population.

METHODS

After a baseline telephone interview, participants were randomized to receive either genetic testing educational print materials (n = 195 women) or general breast cancer education control materials (n = 196 women). One month after receiving these materials, the authors reassessed knowledge, attitudes, and interest in BRCA1/BRCA2 gene testing.

RESULTS

Relative to the breast cancer education control materials, the genetic testing education materials led to increased knowledge, increased perception of the risks and limitations of testing, and decreased interest in obtaining a BRCA1/BRCA2 mutation test.

CONCLUSIONS

These data indicate that preliminary print education can be used to educate low-risk individuals about BRCA1/BRCA2 genetic testing. This approach may be used to educate low-risk individuals about the benefits and risks/limitations of BRCA1/BRCA2 testing, so that they can make informed decisions about whether to pursue genetic counseling.

Tryptophan hydroxylase gene variant and smoking behavior

Approximately 50% of the variance in smoking behavior is attributable to genetic factors. Genes in the serotonin system are plausible candidates because of serotonin's role in mood regulation. The present study examined the association of smoking behavior with a polymorphism in the TPH gene, which codes for a rate limiting enzyme in the biosynthesis of serotonin. A polymorphism in intron 7 has been linked with a variety of traits involving poor impulse control. Participants in this study were 249 Caucasian smokers and 202 nonsmokers recruited through newspaper advertisements. Smokers completed smoking history and nicotine dependence assessments. The overall frequencies of the A- and C-allele were 42% and 58%, respectively. There was no association of TPH alleles with smoking status. However, case series analysis indicated that individuals with the A/A genotype started smoking at age 15.6 years, compared with 17.3 years among smokers with other genotypes. This association was significant in a multivariate regression model controlling for age, education, body mass index (BMI), alcohol use, and medication use. This finding is consistent with previous studies relating the A-allele to impulsive behavior and suggests that it may predispose to early smoking initiation. Future family-based studies are needed to confirm this finding. Published 2001 Wiley-Liss, Inc.

Psychological issues among children of hereditary breast cancer gene (BRCA1/2) testing participants

Children growing up in hereditary breast cancer families may experience diminished psychological well-being. In addition to coping with having a cancer-affected parent or close relatives, these children may focus on their own health risks in light of shared genetic information. While knowledge of a parent's BRCA1/2 negative status may allay a subset of children's worries and fears about cancer, others could experience distressing thought patterns over positive test results. The purpose of this preliminary study is to explore conceptions of health, cancer risk, and psychological adjustment among children in families suggestive of carrying BRCA1/2 susceptibility genes. As part of a longitudinal investigation of the outcomes of BRCA1/2 testing in adults, 20 children of a highly select group of 15 mothers (80% previously affected by breast/ovarian cancer) completed a self-report survey of their beliefs and opinions regarding cancer and genetic testing, stress and worry about cancer, and anxiety, depression, and behavior problems. All information was completed at baseline, prior to the mother's receipt of her genetic test result. The data did not suggest unusually elevated cancer worries or psychological adjustment problems in these children at this point in the parental genetic testing process. However, children with more psychological distress symptoms did experience more frequent thoughts of becoming sick and greater cancer worries. To the extent that learning about a parent's positive test result could exacerbate these tendencies, recommendations to promote child psychological and family communications research that monitor such responses are offered.

Cost of genetic counseling and testing for BRCA1 and BRCA2 breast cancer susceptibility mutations

Counseling and predictive testing are now available for the recently isolated BRCA1 and BRCA2 breast cancer susceptibility genes. We examined the societal costs of providing this counseling and testing to women at risk of having a breast cancer susceptibility mutation. Genetic counselors in a research program prospectively monitored the time necessary to provide counseling and results disclosure. A time-motion study was used to determine time spent on phone calls, preparation, and documentation for counseling. Study participants were surveyed to determine travel time and need for dependent care during counseling. The test cost was calculated using the charge for full BRCA1/2 gene sequencing (Myriad Genetics, Inc.) multiplied by a Medicare-based cost-to-charge ratio. Counselors spent an average of 4.2 h providing genetic counseling for women at risk of having a susceptibility mutation. Genetic counseling without testing cost on average $213, whereas counseling, testing, and disclosure of results totaled $2057. A brief physician-based counseling instead of genetic counselor-based counseling would produce only small reductions in total costs. Providing counseling and testing to the study population averaged $8034 per mutation found. The cost of testing and counseling exceeded $2000. The counseling portion of the cost comprised only 16% of the total cost, with the remainder representing costs associated with testing; thus, alternatives to full genetic counseling that shorten counseling time are unlikely to have a large impact on the overall cost of counseling and testing. The cost of detecting a mutation within a population of women is highly dependent on the prevalence of the mutation in the population.

Effects of coping style and BRCA1 and BRCA2 test results on anxiety among women participating in genetic counseling and testing for breast and ovarian cancer risk

Using the monitoring process model (MPM), the authors examined the immediate effects of coping style and test results on the psychological distress of women at increased risk for breast and/or ovarian cancers. Cases selected for analysis were 107 probands and relatives of positive probands participating in genetic counseling and testing for heritable cancer risk. Specifically, the authors explored the relationships among coping style (high and low monitoring), test results (BRCA1 and BRCA2 mutation carrier and noncarrier status), and psychological distress (state anxiety). Consistent with the MPM, higher monitoring was associated with greater psychological distress while anticipating genetic test results. After test results were disclosed, greater distress was associated with testing positive for a mutation. The implications of the findings for breast and ovarian cancer patients are discussed.

BRCA1/2 testing: complex themes in result interpretation

Since the cloning of BRCA1 and BRCA2, genetic testing for breast and ovarian cancer susceptibility has become more widespread. However, interpretation of test results is not always straightforward. To illustrate this point, five vignettes adapted from actual cases are presented. As these cases demonstrate, in many high-risk families, a deleterious mutation in BRCA1 or BRCA2 is not identified in an affected proband. There are several potential explanations for such a finding, namely that an undetected mutation in BRCA1 or BRCA2 may exist, or there could be a mutation in a rare or undiscovered gene. In addition, the possibility that women with breast cancer represent sporadic cases within hereditary cancer families must also be considered. Finally, the occurrence of BRCA1/2 variants of uncertain significance, often missense mutations, further complicates the risk assessment. In some of these instances, extending testing to relatives can be helpful to clarify results. When hereditary breast cancer cannot be ruled out, individuals may still be at increased risk for cancer and therefore need to obtain appropriate surveillance. The process of genetic counseling is critical both before and after testing to ensure that patients understand the potential medical and psychosocial implications of testing and are aware of available options and resources. A multidisciplinary approach to service delivery, which includes clinicians in genetics and oncology, can facilitate patients' decision making and provide continued access to information and support.

Parental communication of BRCA1/2 genetic test results to children

The aim of this study was to evaluate the likelihood, correlates, and psychological impact of parental communication to children of parents' BRCA1/2 genetic test results for breast cancer risk. Subjects were 133 adult members of high risk families. Sociodemographic, clinical, and psychological distress variables were assessed during a baseline telephone interview conducted prior to patient education and test result notification. Parental communication of test results to children and parental psychological distress and coping efforts were assessed 1 month post-genetic counseling and receipt of test results. Mothers (versus fathers), and persons with higher levels of baseline general distress, were significantly more likely to communicate their test results to children. Post-counseling coping efforts, both active and avoidant, were positively associated with post-counseling distress levels. However, communication of test results to children did not relate to changes in distress. In conclusion, parents with higher levels of pre-counseling general psychological distress may be more likely to communicate their genetic test results to children; however, this act does not minimize their distress and could possibly generate distress in their youngsters. Research is needed to evaluate the process and content of post-test disclosure episodes and the impact on participant, child, and family functioning.

Nicotine metabolism and CYP2D6 phenotype in smokers

We tested the hypothesis that the polymorphic enzyme CYP2D6 is related to nicotine metabolism in 261 healthy subjects enrolling in a smoking cessation clinic. Subjects completed a questionnaire, were given dextromethorphan, and contributed a urine and blood sample. The CYP2D6 phenotype (based on a determination of dextromethorphan and metabolites in an aliquot of overnight urine) and genotype (based on characterization of CYP2D6 variant alleles by a PCR-based method on a subset) were determined. Seventeen poor metabolizers (6.5%) were observed among 261 phenotyped smokers. Nicotine and it chief metabolites, cotinine and trans-3'-hydroxycotinine were measured in the urine and adjusted for pH. All of the nicotine metabolite levels were significantly related to usual and recent smoking. Neither levels of smoking nor nicotine metabolites overall exhibited a relationship to the CYP2D6-deficient metabolizer phenotype. The ratio of nicotine:cotinine + trans-3'-hydroxycotinine, stratified by time since the last cigarette, was unrelated to gender, age, education, race (white/African American), recent alcohol or caffeine consumption, or smoking practices. Subjects in either the lowest quintile or decile metabolic ratio (ultrametabolizers) exhibited a significantly lower nicotine:cotinine + trans-3'-hydroxycotinine ratio after adjustment for recent smoking, pH, and other factors. These data suggest that the polymorphic CYP2D6 gene is not a major contributor to nicotine metabolism in tobacco smokers but may influence the disposition of nicotine in the small subset of the population who are CYP2D6 ultrametabolizers.

Consent to the use of stored DNA for genetics research: a survey of attitudes in the Jewish population

The use of anonymized stored tissue is a routine practice in genetic research. Investigators who utilize stored samples are neither required nor able to obtain informed consent before each use. Many genetic studies, however, are conducted on specific ethnic populations (e.g., Ashkenazi Jews). The results in these cases, although individually anonymous, are not anonymous with respect to the ethnicity of the participants. This lack of group anonymity has led to concern about the possibility of stigmatization and discrimination based on the results of the genetic research. In the present study we surveyed Jewish individuals about their attitudes regarding the practice of using stored DNA samples for genetic research. Specifically, we were interested in whether attitudes about informed consent and willingness to participate in genetics research using stored DNA would depend on the circumstances in which the material was collected (i.e., clinical setting vs. research setting) and the characteristics of the disease or trait under investigation. Overall, most respondents reported that written informed consent should be required and that they would be willing to provide such consent. Participants were most willing to provide consent, however, when the sample had been collected in a research rather than clinical setting. Further, participants were more likely to endorse the need for obtaining consent when the sample was collected in a clinical setting. Finally, participants were significantly less willing to participate in research that examined stereotypical or potentially stigmatizing traits as opposed to research that examined medical or mental illnesses.

Tamoxifen and risk of contralateral breast cancer in BRCA1 and BRCA2 mutation carriers: a case-control study. Hereditary Breast Cancer Clinical Study Group

BACKGROUND

Women with a mutation in BRCA1 or BRCA2 have a high risk of developing breast cancer and of contralateral cancer after the initial diagnosis of breast cancer. Tamoxifen protects against contralateral breast cancer in the general population, but whether it protects against contralateral breast cancer in BRCA1 or BRCA2 mutation carriers is not known.

METHODS

We compared 209 women with bilateral breast cancer and BRCA1 or BRCA2 mutation (bilateral-disease cases), with 384 women with unilateral disease and BRCA1 or BRCA2 mutation (controls) in a matched case-control study. Age and age at diagnosis of breast cancer (range 24-74 years) were much the same in bilateral-disease cases and controls, and both groups had been followed up for the same time for a second primary breast cancer. History of tamoxifen use for first breast cancer was obtained by interview, or by self-administered questionnaire.

FINDINGS

The multivariate odds ratio for contralateral breast cancer associated with tamoxifen use was 0.50 (95% CI 0.28-0.89). Tamoxifen protected against contralateral breast cancer for carriers of BRCA1 mutations (odds ratio 0.38, 95% CI 0.19-0.74) and for those with BRCA2 mutations (0.63, 0.20-1.50). In women who used tamoxifen for 2-4 years, the risk of contralateral breast cancer was reduced by 75%. A reduction in risk of contralateral cancer was also seen with oophorectomy (0.42, 0.22-0.83) and with chemotherapy (0-40, 0.26-0.60).

INTERPRETATION

Tamoxifen use reduces the risk of contralateral breast cancer in women with pathogenic mutations in the BRCA1 or BRCA2 gene. The protective effect of tamoxifen seems independent of that of oophorectomy.

Intention to be tested for prostate cancer risk among African-American men

This study was conducted to identify factors associated with intention to be tested for prostate cancer risk among African-American men. Participants in this study included African-American men (n = 548) who were patients at the University Health Service at the University of Chicago, were 40 to 70 years of age, and did not have a personal history of prostate cancer. Baseline telephone survey data were collected for 413 (75%) men. Respondents were asked if they intended to have a blood test to assess prostate cancer risk. Univariate and multivariate analyses of intention to be tested for risk were performed. Eighty-six percent of the men said that they intended to be tested. Multivariate analysis results show that belief in the efficacy of prostate cancer screening [odds ratio (OR) = 3.6; 95% confidence interval (CI) = 1.4, 9.1] and intention to undergo a prostate cancer-screening (i.e., digital rectal examination and prostate-specific antigen testing; OR = 2.8; 95% CI = 1.3, 6.3) were positively associated with intention to be tested for prostate cancer risk. Being older (OR = 0.4; 95% CI = 0.2, 0.9), having had a prostate cancer-screening examination in the past year (OR = 0.5; 95% CI = 0.2, 1.0), perceiving one's prostate cancer susceptibility to be high (OR = 0.4; 95% CI = 0.2, 0.8), and being fatalistic about prostate cancer prevention (OR = 0.3; 95% CI = 0.2, 0.7) were negatively associated with intention to be tested for risk. Intention to be tested for prostate cancer risk was high among men in the study. Past screening, perceived susceptibility, and beliefs related to early detection might influence receptivity to genetic testing for prostate cancer risk.

Risk communication in genetic testing for cancer susceptibility

Risk communication is an integral part of genetic counseling and testing for cancer susceptibility. This paper reviews the emerging literature on this topic. Three relevant aspects of risk communication are addressed: communication of individual risk, communication of the risks inherent in genetic testing, and family communications related to risk. These studies suggest that (a) most individuals with some family history of cancer, including those at low to moderate risk, overestimate their personal cancer risk; (b) awareness of the risks of genetic testing is limited; (c) decision making about genetic testing is influenced strongly by exaggerated perceptions of personal cancer risk and less so by perceptions of the risks of genetic testing; (d) perceptions of personal risk of cancer are resistant to standard education and counseling approaches; (e) psychologic distress and coping processes influence the processing of risk information and subsequent decision making in genetic testing; and (f) family influences play an important role in risk awareness, genetic testing decisions, and outcomes. To study these issues further, new theoretical models and measures of risk perceptions need to be developed. Both observational and experimental methods should be used to examine both the content and process of risk communication in cancer genetic counseling and testing. Emotional, familial, and sociocultural influences on the risk communication process require special attention.

Psychosocial factors predicting BRCA1/BRCA2 testing decisions in members of hereditary breast and ovarian cancer families

Although BRCA1/2 testing has increasingly entered clinical practice, much is to be learned about the most effective ways to provide counseling to persons potentially interested in receiving test results. The purpose of this study was to identify factors affecting genetic testing decisions in a cohort of hereditary breast and ovarian cancer (HBOC) families presented with the choice to undergo testing. Relatives in these families are known to carry BRCA1 or BRCA2 mutations. Sociodemographics, personality traits, and family functioning were self-assessed using validated psychometric instruments at baseline. Among 172 individuals who participated in pretest education and counseling, 135 (78%) chose to undergo genetic testing and 37 (22%) chose not to be tested. Individuals who chose to undergo genetic testing were more likely to be older (> or =40 years), to have lower levels of optimism, and to report higher levels of cohesiveness in their families. A better understanding of factors that influence interest in predictive testing may help to inform the counseling that occurs prior to genetic testing.

Prophylactic surgery decisions and surveillance practices one year following BRCA1/2 testing

BACKGROUND

Although genetic testing for breast cancer risk is clinically available, its impact on health-related behaviors is unknown. This study examined prophylactic surgery and surveillance behavior during the year following BRCA1/2 gene testing.

METHODS

Participants were female members (n = 216) of hereditary breast-ovarian cancer families (84 mutation carriers, 83 noncarriers and 49 test decliners). In this prospective observational study, utilization of prophylactic surgery and surveillance behavior were assessed 1-year following BRCA1/2 testing.

RESULTS

Only 3% of the unaffected carriers obtained prophylactic mastectomy during the 1-year follow-up period. Among the remaining females, carriers had significantly higher rates of mammography (68%) than noncarriers (44%); (OR = 7.1; C.I. = 1.36-37.1; P = 0.02). However, the adherence rate in carriers was unchanged from baseline, suggesting that this difference is attributable to a reduction in screening among noncarriers. Women ages 25-39 years were significantly less likely to obtain mammograms than those aged 40 years and older. Cancer-related distress had a positive but nonsignificant (P < 0.07) association with adherence in bivariate but not multivariate analysis. With regard to ovarian risk, only 13% of carriers obtained prophylactic oophorectomy; of the remaining female carriers, only 21% reported a CA125 and 15% reported a transvaginal ultrasound.

CONCLUSION

The vast majority of BRCA1/2 carriers may not opt for prophylactic surgery, and many do not adhere to surveillance recommendations. Greater attention to risk communication and medical decision-making is warranted.

Adoption of a health education intervention for family members of breast cancer patients

BACKGROUND

Relatives of breast cancer patients often face substantial uncertainty and psychological stress regarding their own health risks and optimal strategies for prevention and early detection. Efficacious educational and counseling interventions are rarely evaluated for their potential adoption and use in medical practice settings. This study evaluates a health education program for first-degree relatives of breast cancer patients based on the program's potential for being adopted and used by medical practices affiliated with cancer centers.

METHODS

A randomized, controlled trial was implemented in four community hospital-based medical practices. After 9 months, clinical and administrative staff at each practice were given self-administered surveys. Of 90 staff members recruited to respond, useable responses were received from 60 (67%), including 13 physicians (31%), 43 nurses (98%), and four program managers (100%). Participants made self-reports of program awareness, program support, perceived program performance, likelihood of program adoption and use, and barriers to adoption.

RESULTS

A strong majority of respondents (80%) reported that all or most staff agreed with the need for the program. Perceived program performance in meeting goals was generally favorable but varied across sites and across staff types. Overall, 56% of respondents indicated that their practices were likely or highly likely to adopt the program in full. The likelihood of adoption varied substantially across sites and across program components.

CONCLUSIONS

Evaluating the potential for program adoption offers insight for tailoring preventive health interventions and their implementation strategies to improve diffusion in the field of practice.

Spiritual faith and genetic testing decisions among high-risk breast cancer probands

Despite widespread access to genetic testing for the BRCA1 and BRCA2 breast cancer susceptibility genes, little is known about rates or predictors of test use among individuals from newly ascertained high-risk families who have self-referred for genetic counseling/testing. The objective of this study was to examine rates of test use within this population. In addition, we sought to determine whether spiritual faith and psychological factors influenced testing decisions. Participants were 290 women with familial breast cancer. All were offered genetic counseling and testing for alterations in the BRCA1 and BRCA2 genes. Baseline levels of spiritual faith, cancer-specific distress, perceived risk, and demographic factors were examined to identify independent predictors of whether participants received versus declined testing. The final logistic model revealed statistically significant main effects for spiritual faith [odds ratio (OR), 0.2; 95% confidence intervals (CIs), 0.1 and 0.5] and perceived ovarian cancer risk (OR, 2.4; 95% CIs, 1.3 and 4.7) and a statistically significant spiritual faith by perceived risk interaction effect. Among women who perceived themselves to be at low risk of developing breast cancer again, those with higher levels of spiritual faith were significantly less likely to be tested, compared with those with lower levels of faith (OR, 0.2; 95% CIs, 0.1 and 0.5). However, among women with high levels of perceived risk, rates of test use were high, regardless of levels of spiritual faith (OR, 1.2; 95% CIs, 0.4 and 3.0). These results highlight the role that spirituality may play in the decision-making process about genetic testing.

Interacting effects of the serotonin transporter gene and neuroticism in smoking practices and nicotine dependence

Individual differences in propensity to nicotine dependence appear to be mediated, in part, by genetic factors.1 The serotonin transporter gene has a functional polymorphism (5-HTTLPR) which modulates gene transcription and reuptake.2,3 A possible role in nicotine dependence is suggested by a link between 5-HTTLPR and neuroticism,4 a personality trait which has been related to smoking practices.5 In a cross-sectional study of 185 smokers, we utilized multiple linear regression modeling to examine the interacting effects of the 5-HTTLPR and neuroticism on smoking practices and nicotine dependence. Genotype was classified according to the presence or absence of the short (s) allele vs the long (l) allele of 5-HTTLPR (ie, s/s or s/l vs l/l). Models controlled for gender, age, race, and alcohol use. The 5-HTTLPR by neuroticism interaction effect was statistically significant in the models of nicotine intake (P = 0.05), nicotine dependence (P = 0.001), and smoking motivations (smoking to reduce negative mood (P = 0.01); smoking for stimulation (P = 0.01)). The results suggested that neuroticism was positively associated with these smoking practices among smokers with 5-HTTLPR S genotypes (s/s or s/l), but not among smokers with the L genotype (l/l). The 5-HTTLPR may modify the effects of neuroticism on smoking motivations and nicotine dependence. Assessment of 5-HTTLPR genotype and neuroticism may help to identify smokers who are more responsive to psychotropic medications, such as selective serotonin reuptake inhibitors (SSRIs), which are being used in smoking cessation treatment.

Clinical impact of molecular genetic diagnosis, genetic counseling, and management of hereditary cancer. Part II: Hereditary nonpolyposis colorectal carcinoma as a model

Hereditary nonpolyposis colorectal carcinoma (HNPCC) is the most common hereditary form of colorectal carcinoma (CRC) and may account for 5-10% of the total CRC burden. The discovery of DNA mismatch repair (MMR) genes, inclusive of hMSH2, hMLH1, hPMS2, and hMSH6, has enabled the identification of who has and who does not have inordinately increased susceptibility to CRC as well as a litany of extracolonic cancers. Mutation testing has focused on hMSH2 and hMLH1, the most common mutations in HNPCC. The protocol for DNA testing and DNA-based genetic counseling is described in Part I of this study. One hundred ninety-nine bloodline relatives were tested and counseled from five hMLH1 and two hMSH2 families. Their major reason for seeking genetic counseling and DNA testing was to inform their children and other loved ones of their mutation status. Those who sought counseling overestimated their risk for inheriting the mutation and showed a high rate of interest in prophylactic surgery, and many were greatly concerned about insurance discrimination. Knowledge about HNPCC, its molecular genetic diagnosis, surveillance and management opportunities, and genetic counseling implications are still emerging, all in the face of a greater need for physician education regarding all facets of hereditary cancer.

Clinical impact of molecular genetic diagnosis, genetic counseling, and management of hereditary cancer. Part II: Hereditary nonpolyposis colorectal carcinoma as a model

Hereditary nonpolyposis colorectal carcinoma (HNPCC) is the most common hereditary form of colorectal carcinoma (CRC) and may account for 5-10% of the total CRC burden. The discovery of DNA mismatch repair (MMR) genes, inclusive of hMSH2, hMLH1, hPMS2, and hMSH6, has enabled the identification of who has and who does not have inordinately increased susceptibility to CRC as well as a litany of extracolonic cancers. Mutation testing has focused on hMSH2 and hMLH1, the most common mutations in HNPCC. The protocol for DNA testing and DNA-based genetic counseling is described in Part I of this study. One hundred ninety-nine bloodline relatives were tested and counseled from five hMLH1 and two hMSH2 families. Their major reason for seeking genetic counseling and DNA testing was to inform their children and other loved ones of their mutation status. Those who sought counseling overestimated their risk for inheriting the mutation and showed a high rate of interest in prophylactic surgery, and many were greatly concerned about insurance discrimination. Knowledge about HNPCC, its molecular genetic diagnosis, surveillance and management opportunities, and genetic counseling implications are still emerging, all in the face of a greater need for physician education regarding all facets of hereditary cancer.

Patterns of breast cancer screening among lesbians at increased risk for breast cancer

BACKGROUND

Women with a family history of breast cancer (i.e., in a mother, sister or daughter) are at increased risk for this disease. Previous data also suggest that lesbians are at increased risk for breast cancer. While the screening behaviors of women with a family history have been described, little is known about factors that influence screening behaviors of lesbians with the same risk factor profile.

PURPOSE

The purpose of this study was to characterize the perceptions of susceptibility to breast cancer and describe factors that influence adherence to breast cancer screening guidelines in a sample of lesbians with a first-degree relative with a diagnosis of breast cancer.

METHODS

Structured telephone interviews were conducted on a sample of 139 self-identified lesbians who had a first-degree relative with a diagnosis of breast cancer, were between the ages of 35 to 75 and had no previous history of cancer. Cross-sectional data obtained, included socio-demographics, breast cancer risk factors, breast cancer screening patterns, breast cancer perceptions, worries, and knowledge, and barriers and access to health care factors. Individual subject characteristics were examined for their association with adherence to mammography guidelines followed by a multivariate analysis to evaluate the most important combinations of factors. Outcome measures were age-specific adherence to ACS guidelines for both mammography and overall adherence (i.e., mammography, clinical breast examination and breast self-examination).

RESULTS

The 139 lesbians interviewed for this study were young (mean age = 43), almost exclusively white (94%), highly educated (78% = college graduate and beyond), and partnered (68%). In the bivariate analysis of individual factors, being employed and reporting breast cancer worries were significantly and positively associated with adherence to mammography guidelines. Higher income and insurance type were significantly associated with mammography adherence. No factors were significantly associated with overall adherence. Multivariate logistic regression analyses revealed that only income level and degree of breast cancer worries were significantly and positively associated with mammography adherence. However, since there was a high correlation between income level and employment status, a regression model with employment status and worry was also significantly related to mammography adherence.

CONCLUSIONS

In lesbians who are at an increased risk for breast cancer because of family history, breast cancer worries may motivate, rather than deter, adherence for mammography use. High income levels also appear to enable adherence in this population.

IMPLICATIONS

Additional studies are needed to validate these findings, identify the prevalence of lesbians in general samples of women at increased risk for breast cancer, and prospectively test lesbian sensitive educational intervention strategies designed to facilitate adherence to mammography screening guidelines in this population.

Clinical impact of molecular genetic diagnosis, genetic counseling, and management of hereditary cancer. Part II: Hereditary nonpolyposis colorectal carcinoma as a model

Hereditary nonpolyposis colorectal carcinoma (HNPCC) is the most common hereditary form of colorectal carcinoma (CRC) and may account for 5-10% of the total CRC burden. The discovery of DNA mismatch repair (MMR) genes, inclusive of hMSH2, hMLH1, hPMS2, and hMSH6, has enabled the identification of who has and who does not have inordinately increased susceptibility to CRC as well as a litany of extracolonic cancers. Mutation testing has focused on hMSH2 and hMLH1, the most common mutations in HNPCC. The protocol for DNA testing and DNA-based genetic counseling is described in Part I of this study. One hundred ninety-nine bloodline relatives were tested and counseled from five hMLH1 and two hMSH2 families. Their major reason for seeking genetic counseling and DNA testing was to inform their children and other loved ones of their mutation status. Those who sought counseling overestimated their risk for inheriting the mutation and showed a high rate of interest in prophylactic surgery, and many were greatly concerned about insurance discrimination. Knowledge about HNPCC, its molecular genetic diagnosis, surveillance and management opportunities, and genetic counseling implications are still emerging, all in the face of a greater need for physician education regarding all facets of hereditary cancer.

Clinical impact of molecular genetic diagnosis, genetic counseling, and management of hereditary cancer. Part II: Hereditary nonpolyposis colorectal carcinoma as a model

Hereditary nonpolyposis colorectal carcinoma (HNPCC) is the most common hereditary form of colorectal carcinoma (CRC) and may account for 5-10% of the total CRC burden. The discovery of DNA mismatch repair (MMR) genes, inclusive of hMSH2, hMLH1, hPMS2, and hMSH6, has enabled the identification of who has and who does not have inordinately increased susceptibility to CRC as well as a litany of extracolonic cancers. Mutation testing has focused on hMSH2 and hMLH1, the most common mutations in HNPCC. The protocol for DNA testing and DNA-based genetic counseling is described in Part I of this study. One hundred ninety-nine bloodline relatives were tested and counseled from five hMLH1 and two hMSH2 families. Their major reason for seeking genetic counseling and DNA testing was to inform their children and other loved ones of their mutation status. Those who sought counseling overestimated their risk for inheriting the mutation and showed a high rate of interest in prophylactic surgery, and many were greatly concerned about insurance discrimination. Knowledge about HNPCC, its molecular genetic diagnosis, surveillance and management opportunities, and genetic counseling implications are still emerging, all in the face of a greater need for physician education regarding all facets of hereditary cancer.

Pregnancy and risk of early breast cancer in carriers of BRCA1 and BRCA2

BACKGROUND

Early age at first full-term pregnancy and increasing parity are associated with a reduced risk of breast cancer. However, whether pregnancy decreases the risk of early-onset hereditary breast cancer is unknown. There is concern that pregnancy may increase breast-cancer risk in carriers of BRCA1 and BRCA2 germline mutations. We aimed to establish whether pregnancy is a risk factor for hereditary breast cancer.

METHODS

We did a matched case-control study of breast cancer in women who carry deleterious BRCA1 or BRCA2 mutations. Cases were carriers who developed breast cancer by age 40 years, and controls were carriers of the same age without breast cancer, or who were diagnosed with breast cancer after age 40 years. Women who had undergone preventive mastectomy, hysterectomy, or oophorectomy, or who were diagnosed with ovarian cancer before the age at which breast cancer was diagnosed in the matched case were excluded. Information about pregnancies and pregnancy outcome was derived from a questionnaire completed by women in the course of genetic counselling.

FINDINGS

A higher proportion of cases than controls had had a full term pregnancy (173/236 vs 146/236; odds ratio 1.71 [95% CI 1.13-2.62], p=0.01). The mean number of births was also greater for cases than for controls (1.62 vs 1.38, p=0.04). The risk increased with the number of births and did not diminish with time since last pregnancy. There were no significant differences in age at first birth or age at last birth between cases and controls.

INTERPRETATION

Carriers of the BRCA1 and BRCA2 mutations who have children are significantly more likely to develop breast cancer by age 40 than carriers who are nulliparous. Each pregnancy is associated with an increased cancer risk. An early first pregnancy does not confer protection for carriers of BRCA1 or BRCA2 mutations.

Intron variants of the p53 gene are associated with increased risk for ovarian cancer but not in carriers of BRCA1 or BRCA2 germline mutations

Two biallelic polymorphisms in introns 3 and 6 of the p53 gene were analysed for a possible risk-modifying effect for ovarian cancer. Germline DNA was genotyped from 310 German Caucasian ovarian cancer patients and 364 healthy controls. We also typed 124 affected and 276 unaffected female carriers with known deleterious BRCA1 or BRCA2 germline mutation from high-risk breast-ovarian cancer families. Genotyping was based on PCR and high-resolution gel electrophoresis. German ovarian cancer patients who carried the rare allele of the MspI restriction fragment length polymorphism (RELP) in intron 6 were found to have an overall 1.93-fold increased risk (95% confidence internal (CI) 1.27-2.91) which further increased with the age at diagnosis of 41-60 years (odds ratio (OR) 2.71, 95% CI 1.10-6.71 for 41-50 and OR 2.44, 95% CI 1.12-5.28 for 51-60). The 16 bp duplication polymorphism in intron 3 was in a strong linkage to the MspI RFLP. In BRCA1 or BRCA2 mutation carriers, no difference in allele frequency was observed for carriers affected or unaffected with ovarian cancer. Our data suggest that intronic polymorphisms of the p53 gene modify the risk for ovarian cancer patients but not in carriers with BRCA1 or BRCA2 mutations.

Bilateral prophylactic mastectomy decision making: A vignette study

BACKGROUND

Little is known about the perception of bilateral prophylactic mastectomy (BPM), and whether perceptions are influenced by a family history of breast cancer. It is also unclear what factors may play a role in selecting BPM for follow-up care.

METHODS

Samples of predominantly Caucasian, well-educated women with (n = 129) and without (n = 104) family histories of breast cancer were provided a vignette of a woman at increased risk. They selected one of two follow-up options: (1) clinical breast examination, breast self exam, and annual mammography or (2) BPM.

RESULTS

The samples did not differ on the decision to select BPM (29.5% vs 22.1%). The family history sample reported worry about breast cancer as a problem (34.4%) more often than women with no history (15.7%). Multivariate analysis found worry and estimated 10-year risk of the woman in the vignette as significant predictors of selecting BPM.

CONCLUSIONS

Approximately 25% of our sample selected BPM as the preferred option. The majority supported the need to discuss BPM among women at increased risk. Finally, both factors associated with the selection of BPM (worry, risk assessment) are potentially amenable to psychosocial or educational approaches. There is a clear need for assessment of worry and risk perception prior to surgical decision making.