Benefits of a brief psychological intervention targeting fear of cancer recurrence in people at high risk of developing another melanoma: 12-month follow-up results of a randomized controlled trial.

BACKGROUND: People with melanoma want and need effective interventions for living with fear of cancer recurrence (FCR). OBJECTIVES: This study reports the 12-month outcomes of a brief, psychological intervention designed to reduce FCR in people at high risk of developing another primary melanoma compared with usual care. METHODS: In this two-arm randomized controlled trial, adults previously diagnosed with stage 0, I or II melanoma were randomly allocated to the intervention (n = 80) or control (usual care) arm (n = 84). The trial was registered with the Australian and New Zealand Clinical Trials Registry on 19 March 2013 (registration: ACTRN12613000304730). The intervention comprised a 76-page psychoeducational resource and three individually tailored, telephone-based sessions with a psychologist, scheduled at specific time points around participants' dermatological appointments. The primary outcome was the level of self-reported fear of new or recurrent melanoma assessed at 12 months postintervention using the severity subscale of the Fear of Cancer Recurrence Inventory. RESULTS: Compared with the control arm, the intervention group reported significantly lower FCR at 12 months postintervention; the between-group mean difference was -1·41 for FCR severity [95% confidence interval (CI) -2·6 to -0·2; P = 0·02] and -1·32 for FCR triggers (95% CI -2·6 to -0·02; P = 0·04). The odds ratio for FCR severity scores ≥13 (54% intervention, 63% control) was 0·59 (95% CI 0·30-1·14, P = 0·12). There were no differences between groups in secondary outcomes, such as anxiety, depression or health-related quality of life. CONCLUSIONS: The previously reported 6-month benefits of this brief, patient-centred psychological intervention in reducing FCR were found to continue 12 months postintervention, with no known adverse effects, supporting implementation as part of routine melanoma care.

Development and external validation study of a melanoma risk prediction model incorporating clinically assessed naevi and solar lentigines.

BACKGROUND: Melanoma risk prediction models could be useful for matching preventive interventions to patients' risk. OBJECTIVES: To develop and validate a model for incident first-primary cutaneous melanoma using clinically assessed risk factors. METHODS: We used unconditional logistic regression with backward selection from the Australian Melanoma Family Study (461 cases and 329 controls) in which age, sex and city of recruitment were kept in each step, and we externally validated it using the Leeds Melanoma Case-Control Study (960 cases and 513 controls). Candidate predictors included clinically assessed whole-body naevi and solar lentigines, and self-assessed pigmentation phenotype, sun exposure, family history and history of keratinocyte cancer. We evaluated the predictive strength and discrimination of the model risk factors using odds per age- and sex-adjusted SD (OPERA) and the area under curve (AUC), and calibration using the Hosmer-Lemeshow test. RESULTS: The final model included the number of naevi ≥ 2 mm in diameter on the whole body, solar lentigines on the upper back (a six-level scale), hair colour at age 18 years and personal history of keratinocyte cancer. Naevi was the strongest risk factor; the OPERA was 3·51 [95% confidence interval (CI) 2·71-4·54] in the Australian study and 2·56 (95% CI 2·23-2·95) in the Leeds study. The AUC was 0·79 (95% CI 0·76-0·83) in the Australian study and 0·73 (95% CI 0·70-0·75) in the Leeds study. The Hosmer-Lemeshow test P-value was 0·30 in the Australian study and < 0·001 in the Leeds study. CONCLUSIONS: This model had good discrimination and could be used by clinicians to stratify patients by melanoma risk for the targeting of preventive interventions. What's already known about this topic? Melanoma risk prediction models may be useful in prevention by tailoring interventions to personalized risk levels. For reasons of feasibility, time and cost many melanoma prediction models use self-assessed risk factors. However, individuals tend to underestimate their naevus numbers. What does this study add? We present a melanoma risk prediction model, which includes clinically-assessed whole-body naevi and solar lentigines, and self-assessed risk factors including pigmentation phenotype and history of keratinocyte cancer. This model performs well on discrimination, the model's ability to distinguish between individuals with and without melanoma, and may assist clinicians to stratify patients by melanoma risk for targeted preventive interventions.

Associations of pigmentary and naevus phenotype with melanoma risk in two populations with comparable ancestry but contrasting levels of ambient sun exposure.

BACKGROUND: People at high risk of developing melanoma are usually identified by pigmentary and naevus phenotypes. OBJECTIVE: We examined whether associations of these phenotypes with melanoma risk differed by ambient sun exposure or participant characteristics in two population-based, case-control studies with comparable ancestry but different ambient sun exposure. METHODS: Data were analysed from 616 cases and 496 controls from the Australian Melanoma Family Study and 2012 cases and 504 controls from the Leeds (UK) case-control study. Questionnaire, interview and dermatological skin examination data were collected using the same measurement protocols. Relative risks were estimated as odds ratios using unconditional logistic regression, adjusted for potential confounders. RESULTS: Hair and skin colour were the strongest pigmentary phenotype risk factors. All associations of pigmentary phenotype with melanoma risk were similar across countries. The median number of clinically assessed naevi was approximately three times higher in Australia than Leeds, but the relative risks for melanoma associated with each additional common or dysplastic naevus were higher for Leeds than Australia, especially for naevi on the upper and lower limbs. Higher naevus counts on the head and neck were associated with a stronger relative risk for melanoma for women than men. The two countries had similar relative risks for melanoma based on self-reported naevus density categories, but personal perceptions of naevus number differed by country. There was no consistent evidence of interactions between phenotypes on risk. CONCLUSIONS: Classifying people at high risk of melanoma based on their number of naevi should ideally take into account their country of residence, type of counts (clinical or self-reported), body site on which the naevus counts are measured and sex. The presence of naevi may be a stronger indicator of a genetic predisposition in the UK than in Australia based on less opportunity for sun exposure to influence naevus development.

Circulating tumour DNA predicts response to anti-PD1 antibodies in metastatic melanoma.

BACKGROUND: Programmed death 1 (PD1) inhibitors are now a foundation of medical management of metastatic melanoma. This study sought to determine whether circulating tumour DNA (ctDNA) provides useful early response and prognostic information. PATIENTS AND METHODS: We evaluated the relationship between pre-treatment and early on treatment ctDNA and outcome in melanoma patients treated with PD1 inhibitors alone or in combination with ipilimumab. RESULTS: ctDNA was detected in 40/76 patients (53%) at baseline, and correlated with stage, LDH levels, disease volume and ECOG performance. RECIST response was 72% (26/36) in group A (undetectable ctDNA at baseline), 77% (17/22) in group B (elevated ctDNA at baseline but undetectable within 12 weeks of therapy) and 6% (1/18) in group C (elevated ctDNA at baseline and remained elevated during treatment). The median PFS was not reached in groups A and B and was 2.7 months for group C [hazard ratio (HR) 0.09; P < 0.001 for group A versus C, and 0.16; P < 0.001 for group B versus C]. The median OS was not reached for groups A and B and was 9.2 months for group C (HR 0.02; P < 0.001 for group A versus C and 0.14; P < 0.001 for group B versus C). The poor outcome measures associated with group C remained significant in multivariate analysis adjusted for LDH, performance status, tumour stage and disease volume. The predictive value for ctDNA for response was confirmed in a separate validation cohort (n = 29, P < 0.01). CONCLUSION: Longitudinal assessment of ctDNA in metastatic melanoma patients receiving treatment with PD1 inhibitors is an accurate predictor of tumour response, PFS and OS. Patients who had a persistently elevated ctDNA on therapy had a poor prognosis, and this may guide combination and sequencing of subsequent therapies.

Protocol for a within-trial economic evaluation of a psychoeducational intervention tailored to people at high risk of developing a second or subsequent melanoma.

INTRODUCTION: Psychological support programmes are not currently funded for people with a history of melanoma. A major barrier to the implementation of effective psychological interventions in routine clinical care is a lack of cost-effectiveness data. This paper describes the planned economic evaluation alongside a randomised controlled trial of a psychoeducational intervention for people with a history of melanoma who are at high risk of developing new primary disease. METHOD AND ANALYSIS: The economic evaluation is a within-trial analysis to evaluate the incremental costs and health outcomes of a psychoeducational intervention compared to usual care from the perspective of the Australian healthcare system. Cost-effectiveness and cost-utility analyses will be conducted, providing estimates of the cost to reduce fear of melanoma recurrence and the cost per quality-adjusted life-year (QALY) gained. Fear of melanoma recurrence will be measured using the Fear of Cancer Recurrence Inventory and preference-based quality of life measured using the Assessment of Quality of Life-8 Dimensions (AQoL-8D) instrument. The AQoL-8D will provide utilities for estimation of QALYs in the cost-utility analysis. Unit costs of health services and medicines will be taken from the Medicare Benefits Schedule and the Pharmaceutical Benefits Scheme national databases. Health outcomes, and health service and medication use will be collected at baseline, 6 and 12 months follow-up. The within-trial analysis will be conducted at 12 months, consistent with the end point of the trial. ETHICS AND DISSEMINATION: Approval to conduct the study was granted by the Sydney Local Health District (RPAH zone) Ethics Review Committee (X13-0065 and HREC/13/RPAH/86), the Department of Health and Ageing Human Research Ethics Committee (21/2013), the University of Sydney Human Research Ethics Committee (2013/595), and the Australian Institute of Health and Welfare Ethics Committee (EO 2013/4/58). TRIAL REGISTRATION NUMBER: ACTRN12613000304730; Pre-results.

Doctors' recognition and management of melanoma patients' risk: An Australian population-based study.

BACKGROUND: Guidelines recommend that health professionals identify and manage individuals at high risk of developing melanoma, but there is limited population-based evidence demonstrating real-world practices. OBJECTIVE: A population-based, observational study was conducted in the state of New South Wales, Australia to determine doctors' knowledge of melanoma patients' risk and to identify factors associated with better identification and clinical management. METHODS: Data were analysed for 1889 patients with invasive, localised melanoma in the Melanoma Patterns of Care study. This study collected data on all melanoma diagnoses notified to the state's cancer registry during a 12-month period from 2006 to 2007, as well as questionnaire data from the doctors involved in their care. RESULTS: Three-quarters (74%) of patients had doctors who were aware of their risk factor status with respect to personal and family history of melanoma and the presence of many moles. Doctors working in general practice, skin cancer clinics and dermatology settings had better knowledge of patients' risk factors than plastic surgeons. Doctors were 15% more likely to know the family history of younger melanoma patients (<40years) than of those ≥80 years (95% confidence interval 4-26%). Early detection-related follow-up advice was more likely to be given to younger patients, by doctors aware of their patients' risk status, by doctors practising in plastic surgery, dermatology and skin cancer clinic settings, and by female doctors. CONCLUSION: Both patient-related and doctor-related factors were associated with doctors' recognition and management of melanoma patients' risk and could be the focus of strategies for improving care.

Clinical practice guidelines for identification, screening and follow-up of individuals at high risk of primary cutaneous melanoma: a systematic review.

Understanding how individuals at high-risk of primary cutaneous melanoma are best identified, screened and followed up will help optimize melanoma prevention strategies and clinical management. We conducted a systematic review of international clinical practice guidelines and documented the quality of supporting evidence for recommendations for clinical management of individuals at high risk of melanoma. Guidelines published between January 2000 and July 2014 were identified from a systematic search of Medline, Embase and four guideline databases; 34 guidelines from 20 countries were included. High-risk characteristics that were consistently reported included many melanocytic naevi, dysplastic naevi, family history, large congenital naevi, and Fitzpatrick Type I and II skin types. Most guidelines identify risk factors and recommend that individuals at high risk of cutaneous melanoma be monitored, but only half of the guidelines provide recommendations for screening based on level of risk. There is disagreement in screening and follow-up recommendations for those with an increased risk of future melanoma. High-level evidence supports long-term screening of individuals at high risk and monitoring using dermoscopy. Evidence is low for defining screening intervals and duration of follow-up, and for skin self-examination, although education about skin self-examination is widely encouraged. Clinical practice guidelines would benefit from a dedicated section for identification, screening and follow-up of individuals at high risk of melanoma. Guidelines could be improved with clear definitions of multiple naevi, family history and frequency of follow-up. Research examining the benefits and costs of alternative management strategies for groups at high risk will enhance the quality of recommendations.

Mutant B-RAF-Mcl-1 survival signaling depends on the STAT3 transcription factor.

Approximately 50% of melanomas depend on mutant B-RAF for proliferation, metastasis and survival. The inhibition of oncogenic B-RAF with highly targeted compounds has produced remarkable albeit short-lived clinical responses in B-RAF mutant melanoma patients. Reactivation of signaling downstream of B-RAF is frequently associated with acquired resistance to B-RAF inhibitors, and the identification of B-RAF targets may provide new strategies for managing melanoma. Oncogenic B-RAF(V600E) is known to promote the stabilizing phosphorylation of the anti-apoptotic protein Mcl-1, implicated in melanoma survival and chemoresistance. We now show that B-RAF(V600E) signaling also induces the transcription of Mcl-1 in melanocytes and melanoma. We demonstrate that activation of STAT3 serine-727 and tyrosine-705 phosphorylations is promoted by B-RAF(V600E) activity and that the Mcl-1 promoter is dependent on a STAT consensus-site for B-RAF-mediated activation. Consequently, suppression of STAT3 activity disrupted B-RAF(V600E)-mediated induction of Mcl-1 and reduced melanoma cell survival. We propose that STAT3 has a central role in the survival and contributes to chemoresistance of B-RAF(V600E) melanoma.

Melanoma survivors at high risk of developing new primary disease: a qualitative examination of the factors that contribute to patient satisfaction with clinical care.

BACKGROUND: Providing ongoing clinical care that adequately addresses patients' medical, psychosocial and information needs is challenging, particularly for patient groups at increased risk of developing life-threatening disease such as malignant melanoma. This study examined a model of clinical care developed by the High Risk Clinic (HRC) of the Sydney Melanoma Diagnostic Centre in relation to patient satisfaction. METHODS: Semi-structured telephone interviews were conducted and analyzed using the framework of Miles and Huberman, and themes were organized using the qualitative software package, QSR NVivo8. RESULTS: Twenty HRC patients participated in the study (nine men, 11 women; mean age 57.6 years, age range 34-74 years; response rate 91%). Satisfaction with clinical care at the HRC was high. Factors contributing to patient satisfaction included: rapid and regular access to physicians who were perceived by participants as experts, the development of confidence and trust in one's treating doctor, and a sense of being cared about and understood by one's healthcare team. Although one-third of the participants reported some inconveniences in attending the clinic, these were viewed as minor difficulties and not significant barriers to care. Formal psychological support was not sought or expected by participants, although many expressed long-standing melanoma-related fears and concerns. CONCLUSIONS: Accessible, expert medical attention, delivered in a patient-centered manner was integral to melanoma survivors' satisfaction with clinical management. Appropriate referrals to psychological support may further increase satisfaction with clinical care.

Skin cancer screening behaviours among individuals with a strong family history of malignant melanoma.

BACKGROUND: This study examined the prevalence and correlates of skin cancer screening behaviours among individuals at high risk of developing melanoma due to strong family history. METHODS: A total of 120 individuals with a known family-specific CDKN2A mutation (72% response rate) completed a self-report questionnaire assessing annual frequency of skin self-examination (SSE), clinical skin examination (CSE) and a variety of potential demographic, clinical and psychosocial correlates. RESULTS: In the past 12 months, 50% of participants reported engaging in SSE at least four times, and 43% of participants had undergone at least one CSE. Engagement in SSE was associated with doctor recommendation (ß=1.77, P=0.001), confidence in one's ability to perform SSE (ß=1.44, P<0.0001), positive beliefs about melanoma treatment (ß=0.77, P=0.002) and intention to perform SSE in the future (ß=1.69, P<0.0001). These variables accounted for 59% of the variance in SSE behaviour. Further, information-seeking style moderated the relationship between anxiety and SSE (ß=1.02, P=0.004). Annual uptake of CSE was associated with doctor recommendation (ß=2.21, P<0.0001) and intention to undergo CSE in the future (ß=1.19, P=0.001). CONCLUSION: In comparison with clinical guidelines, it appears that individuals at high risk of developing melanoma engage in suboptimal levels of skin surveillance. Improved doctor-patient communication, as well as psycho-education and behavioural support, may be viable means of improving early skin cancer detection behaviours in this high-risk population.

Association of MC1R variants and host phenotypes with melanoma risk in CDKN2A mutation carriers: a GenoMEL study.

BACKGROUND: Carrying the cyclin-dependent kinase inhibitor 2A (CDKN2A) germline mutations is associated with a high risk for melanoma. Penetrance of CDKN2A mutations is modified by pigmentation characteristics, nevus phenotypes, and some variants of the melanocortin-1 receptor gene (MC1R), which is known to have a role in the pigmentation process. However, investigation of the associations of both MC1R variants and host phenotypes with melanoma risk has been limited. METHODS: We included 815 CDKN2A mutation carriers (473 affected, and 342 unaffected, with melanoma) from 186 families from 15 centers in Europe, North America, and Australia who participated in the Melanoma Genetics Consortium. In this family-based study, we assessed the associations of the four most frequent MC1R variants (V60L, V92M, R151C, and R160W) and the number of variants (1, ≥2 variants), alone or jointly with the host phenotypes (hair color, propensity to sunburn, and number of nevi), with melanoma risk in CDKN2A mutation carriers. These associations were estimated and tested using generalized estimating equations. All statistical tests were two-sided. RESULTS: Carrying any one of the four most frequent MC1R variants (V60L, V92M, R151C, R160W) in CDKN2A mutation carriers was associated with a statistically significantly increased risk for melanoma across all continents (1.24 × 10(-6) ≤ P ≤ .0007). A consistent pattern of increase in melanoma risk was also associated with increase in number of MC1R variants. The risk of melanoma associated with at least two MC1R variants was 2.6-fold higher than the risk associated with only one variant (odds ratio = 5.83 [95% confidence interval = 3.60 to 9.46] vs 2.25 [95% confidence interval = 1.44 to 3.52]; P(trend) = 1.86 × 10(-8)). The joint analysis of MC1R variants and host phenotypes showed statistically significant associations of melanoma risk, together with MC1R variants (.0001 ≤ P ≤ .04), hair color (.006 ≤ P ≤ .06), and number of nevi (6.9 × 10(-6) ≤ P ≤ .02). CONCLUSION: Results show that MC1R variants, hair color, and number of nevi were jointly associated with melanoma risk in CDKN2A mutation carriers. This joint association may have important consequences for risk assessments in familial settings.

Issues faced by unaffected men with a family history of prostate cancer: a multidisciplinary overview.

PURPOSE: Despite the established importance of the role of family history in prostate cancer, relatively little research encompasses the psychosocial issues relevant to unaffected men with a family history of prostate cancer. To determine the completeness and quality of available literature on the issues faced by men with a high risk of prostate cancer, we conducted a multidisciplinary review of the literature to provide some guidance on the information that clinicians might provide to men who are concerned about family history. MATERIALS AND METHODS: A structured literature search was conducted by a multidisciplinary team of clinicians and researchers who reviewed the medical and psychosocial literature, and identified 21 relevant studies. RESULTS: Research suggests that many high risk patients are concerned about the risk of prostate cancer, and some may significantly overestimate that risk. Several studies have shown high screening rates among high risk patients and high levels of interest in genetic testing for prostate cancer risk should it become available, yet many men also report a desire for more information about their personal risk and risk management options. CONCLUSIONS: Given the lack of clear data on the efficacy of prostate cancer screening among high risk patients, clinicians could consider providing men who are concerned about family history with information on their personal risk, help them to clarify the potential benefits, limitations and harms of prostate cancer screening in their situation, and then support their choice regarding the management of prostate cancer risk.

Predictors of psychological distress among individuals with a strong family history of malignant melanoma.

Despite rapid advancements in molecular genetics research, little is known about the psychological experiences of individuals with a family history of melanoma. The present study aimed to identify factors contributing to psychological distress among affected and unaffected individuals with a strong family history of melanoma. A total of 121 adults who had recently been informed of the identification of a family-specific mutation in the CDKN2A melanoma susceptibility gene, completed a self-report questionnaire assessing cancer-specific and generalized distress, and a variety of potential predictors. Having a personal history of melanoma (OR = 3.37, p = 0.033), perceiving greater family implications of melanoma (OR = 2.52, p < 0.0001), and the tendency to monitor for threatening information (OR = 3.12, p = 0.008) were associated with melanoma-specific distress. Being childless (beta = 2.09, p = 0.007), perceiving sun exposure as an important cause of melanoma (beta = 1.15, p = 0.015), and perceiving greater family implications of melanoma (beta = 1.02, p = 0.002) were associated with greater generalized anxiety, while monitoring moderated the relationship between endorsement of a genetic model of melanoma and generalized anxiety (p = 0.005). As in other common familial cancers, distress was relatively uncommon in this familial melanoma cohort, even after notification of the presence of a family mutation. Participants do not contemplate their melanoma risk in isolation, but evaluate their risk vis-à-vis the experiences of their relatives.

Imatinib disposition and ABCB1 (MDR1, P-glycoprotein) genotype.

The aim of this study was to explore the impact of individual variation in drug elimination on imatinib disposition. Twenty-two patients with gastrointestinal stromal tumor or chronic myeloid leukemia initially received imatinib 600 mg daily with dosage subsequently toxicity adjusted. Pharmacokinetic parameters on day 1 and at steady-state were compared with elimination phenotype and single-nucleotide polymorphisms of CYP3A5 and ABCB1. A fivefold variation in estimated imatinib clearance (CL/F) was present on day 1 and mean CL/F had fallen by 26% at steady state. This reduction in imatinib CL/F was associated with ABCB1 genotype, being least apparent in thymidine homozygotes at the 1236T>C, 2677G>T/A and 3435C>T loci. Toxicity-related dose reduction also tended to be less common in these individuals. ABCB1 genotype was associated with steady-state CL/F due to an apparent genotype-specific influence of imatinib on elimination. Further evaluation of ABCB1 genotype and imatinib dosage is warranted.

Impaired inhibition of NF-kappaB activity by melanoma-associated p16INK4a mutations.

The cyclin-dependent kinase inhibitor p16INK4a has been identified as tumor suppressor and melanoma predisposition gene. While its cell cycle inhibitory ability is important in protecting cells from uncontrolled growth and possible tumor formation, other functions of p16INK4a are likely to contribute to its nature as a tumor suppressor. p16INK4a binding and inhibition of the transcription factor NF-kappaB has been shown and is consistent with the reports of abnormally increased NF-kappaB activity in various cancers including melanoma. Here, we present evidence that wild type p16INK4a binds to the NF-kappaB subunit RelA more efficiently than melanoma-associated p16INK4a mutations. Furthermore, whereas wild type p16INK4a strongly inhibits NF-kappaB transcriptional activity, a subset of melanoma-associated p16INK4a mutants show reduced NF-kappaB inhibitory function. p16INK4a does not affect NF-kappaB nuclear translocation or DNA binding, suggesting a mechanism that reduces NF-kappaB transactivation activity.

X inactivation, DNA deletion, and microsatellite instability in common acquired melanocytic nevi.

We have investigated several molecular characteristics of common acquired melanocytic nevi to clarify their relationship to malignant melanoma, which is characterized by clonality and the progressive accumulation of DNA deletions. Twenty-four common acquired nevi were subjected to analysis for loss of heterozygosity at four loci on chromosome 9p and six loci on 10q that are commonly deleted in melanoma, but no deletions were seen. X inactivation analysis was performed in lesions from females, using the methylation-sensitive restriction HpaII site in the CAG microsatellite repeat (HUMARA) in exon 1 of the androgen receptor (AR) gene. In 14 melanomas, 11 (92%) were confirmed to have skewed X inactivation, consistent with monoclonality, as were 16 (80%) of 20 benign nevi. One nevus (5%) and 4 (33%) of 12 melanomas also showed loss of heterozygosity at HUMARA. One nevus showed an additional allele, consistent with low level microsatellite instability, at one of the 11 loci that were examined. Common melanocytic nevi, therefore, arise by apparently clonal proliferation, but they do not share chromosomal deletions that are characteristic of melanoma. However, skewed X inactivation patterns were seen in some samples of adjacent microdissected normal epidermis.

The intronic G13964C variant in p53 is not a high-risk mutation in familial breast cancer in Australia.

BACKGROUND: Mutations in BRCA1 and BRCA2 account for approximately 50% of breast cancer families with more than four affected cases, whereas exonic mutations in p53, PTEN, CHK2 and ATM may account for a very small proportion. It was recently reported that an intronic variant of p53--G13964C--occurred in three out of 42 (7.1%) 'hereditary' breast cancer patients, but not in any of 171 'sporadic' breast cancer control individuals (P = 0.0003). If this relatively frequent occurrence of G13964C in familial breast cancer and absence in control individuals were confirmed, then this would suggest that the G13964C variant plays a role in breast cancer susceptibility. METHOD: We genotyped 71 familial breast cancer patients and 143 control individuals for the G13964C variant using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis. RESULTS: Three (4.2%; 95% confidence interval [CI] 0-8.9%) G13964C heterozygotes were identified. The variant was also identified in 5 out of 143 (3.5%; 95% CI 0.6-6.4%) control individuals without breast cancer or a family history of breast cancer, however, which is no different to the proportion found in familial cases (P = 0.9). CONCLUSION: The present study would have had 80% power to detect an odds ratio of 4.4, and we therefore conclude that the G13946C polymorphism is not a 'high-risk' mutation for familial breast cancer.

Functional impairment of melanoma-associated p16(INK4a) mutants in melanoma cells despite retention of cyclin-dependent kinase 4 binding.

PURPOSE: Melanoma-associated germ-line mutations affecting the tumor suppressor and cyclin-dependent kinase (CDK) inhibitor, CDKN2A/p16(INK4a) have been identified in >100 melanoma-prone families. To predict the melanoma risk for carriers of specific mutations, it is useful to test the function of the mutant proteins in biochemical assays; however, it is unclear how well these results correlate with their cellular effects. We examined the relationship between loss of CDK binding by mutant proteins and various measures of cellular growth in melanoma cells. EXPERIMENTAL DESIGN: The cellular activities of four melanoma-associated p16(INK4a) mutations (Arg24Pro, Ala36Pro, Met53Ile, and Val126Asp) were compared by use of inducible expression in stably transfected melanoma cells, deficient in expression of the endogenous protein, and compared with their ability to bind CDK4. RESULTS: The cell cycle-inhibitory activity of all of the mutants was profoundly reduced, and partially retained capacity for CDK4 binding in functional assays did not correlate with significant preservation of cell cycle-regulatory function. CONCLUSION: Testing of p16(INK4a) interactions with CDKs in protein-binding assays is an unreliable predictor of mutant p16(INK4a) function in cells. In addition to exhibiting reduced stability, these mutant proteins may also be defective in interaction with cellular targets other than CDKs.

Mutations in the INK4a/ARF melanoma susceptibility locus functionally impair p14ARF.

The INK4a/ARF locus encodes two cell cycle regulatory proteins, the cyclin-dependent kinase inhibitor, p16(INK4a), and the p53 activator, p14(ARF). Germline mutations in this locus are associated with melanoma susceptibility in 20-40% of multiple case melanoma families. Many of these mutations specifically impair p16(INK4a), whereas mutations uniquely targeting p14(ARF) are rare. Nevertheless, the importance of p14(ARF) has not been excluded because more than 40% of INK4a/ARF alterations affect p16(INK4a) and p14(ARF). We now report that p14(ARF) is functionally impaired in melanoma kindreds carrying INK4a/ARF mutations. Of the seven INK4a/ARF mutations tested, three altered the subcellular distribution of p14(ARF) and diminished the ability of p14(ARF) to activate the p53 pathway. This work establishes the importance of p14(ARF) in melanoma predisposition.