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.

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.

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.

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.

Deoxyadenosine triphosphate as a mediator of deoxyguanosine toxicity in cultured T lymphoblasts.

The mechanism by which 2'-deoxyguanosine is toxic for lymphoid cells is relevant both to the severe cellular immune defect of inherited purine nucleoside phosphorylase (PNP) deficiency and to attempts to exploit PNP inhibitors therapeutically. We have studied the cell cycle and biochemical effects of 2'-deoxyguanosine in human lymphoblasts using the PNP inhibitor 8-aminoguanosine. We show that cytostatic 2'-deoxyguanosine concentrations cause G1-phase arrest in PNP-inhibited T lymphoblasts, regardless of their hypoxanthine guanine phosphoribosyltransferase status. This effect is identical to that produced by 2'-deoxyadenosine in adenosine deaminase-inhibited T cells. 2'-Deoxyguanosine elevates both the 2'-deoxyguanosine-5'-triphosphate (dGTP) and 2'-deoxyadenosine-5'-triphosphate (dATP) pools; subsequently pyrimidine deoxyribonucleotide pools are depleted. The time course of these biochemical changes indicates that the onset of G1-phase arrest is related to increase of the dATP rather than the dGTP pool. When dGTP elevation is dissociated from dATP elevation by coincubation with 2'-deoxycytidine, dGTP does not by itself interrupt transit from the G1 to the S phase. It is proposed that dATP can mediate both 2'-deoxyguanosine and 2'-deoxyadenosine toxicity in T lymphoblasts.

Effect of gallium on DNA synthesis by human T-cell lymphoblasts.

We have studied the antiproliferative effects of gallium nitrate in cultured CCRF-CEM lymphoblasts. The 50% inhibitory dose for these cells was 120 microM, and after 24 h at a cytostatic concentration (480 microM) S-phase arrest was observed by DNA flow cytometry. Deoxyribonucleoside triphosphate pools were all reduced (dATP, dGTP, and dCTP by 50%, dTTP by 25%), suggesting inhibition of ribonucleotide reductase. Administration of tracer amounts (0.5 microM) of either [3H]uridine or [3H]deoxyuridine confirmed that DNA synthesis had been inhibited to 20% of control rates by gallium. Further, the flow of the ribonucleoside into the dTTP pool and DNA was selectively reduced compared to that of the deoxyribonucleoside. Gallium decreased the specific activity of dTTP labeled from uridine by 50%, whereas the specific activity of dTTP labeled from deoxyuridine was increased 2.5-fold. Thus counts in DNA derived from [3H]uridine were decreased by more than 80%, while counts in DNA derived from [3H]deoxyuridine were virtually unaltered. Uridine incorporation into RNA was not affected. Gallium did not significantly alter the capacity of permeabilized naive cells to incorporate [3H]dTTP into DNA, while 24-h gallium pretreatment (which increased the percentage of S-phase cells) produced a modest increase in [3H]dTTP incorporation, indicating that any effect of gallium on DNA polymerase alpha is minor. Gallium treatment did not induce or inhibit the repair of DNA single strand breaks. These data demonstrate that gallium inhibits replicative DNA synthesis, with the major specific enzyme target probably being ribonucleotide reductase.

Ribonucleotide reductase M1 subunit in cellular proliferation, quiescence, and differentiation.

Ribonucleotide reductase catalyzes the first unique, rate-limiting step in DNA synthesis; both its large (M1) and small (M2) subunits are necessary for activity. While direct studies of M2 expression have previously shown a tight correlation with S phase, the kinetic features of M1-expressing cells have remained ill defined. Therefore we have, using immunofluorescence flow cytometry, analyzed changes in whole cell M1 levels and DNA content during various cell cycle and differentiation events. In asynchronous cultures M1 levels are sustained throughout the cell cycle, including G1 phase when M2 levels and ribonucleotide reductase catalytic activity are known to be very low. In contrast M1 is virtually absent from quiescent lymphocytes but is expressed following mitogen stimulation, shortly before S phase cells appear. M1 declines to low levels in "plateau phase" cultures, the major reduction occurring in cells with 2n (G0/G1) DNA content. HL-60 promyelocytic leukemia cells, induced into either myeloid or monocyte-macrophage differentiation, show a similar marked decrease in M1 levels concomitant with the cessation of cell division. We conclude that the M1 subunit of ribonucleotide reductase is constitutively expressed by cycling cells. It is acquired during stimulated transition from G0 to G1 and is lost during exit to G0 or terminal differentiation. This pattern of expression suggests that determination of cellular M1 content may be useful in distinguishing proliferating (including G1) and quiescent (including G0) cells in vivo.

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.

Two arginine rich domains in the p14ARF tumour suppressor mediate nucleolar localization.

The INK4a/ARF locus encodes two distinct tumour suppressors, p16INK4a and p14ARF, that regulate cell cycle progression via the pRB and p53 pathways, respectively. The ARF protein inhibits hdm2 activity, leading to the stabilization of the p53 tumour suppressor and cell cycle inhibition. The amino-terminal domain of human p14ARF and of the mouse homologue, p19ARF, is sufficient for these effects. This domain is also sufficient for the nucleolar localization of the mouse ARF protein. In contrast, we show that the human ARF protein requires two arginine rich domains, one in the amino- and the other in the carboxy-terminus, for nucleolar targeting. The amino-terminal nucleolar-targeting domain of p14ARF is also important for ARF-hdm2 binding and cell cycle inhibition. The carboxy-terminal p14ARF nucleolar localization domain lies within the shared INK4a/ARF exon 2, and is mutated in a small number of melanoma-prone kindreds. The INK4a/ARF exon2-mutations could affect the function of both the p16INK4a and p14ARF tumour suppressors. Oncogene (2000).

Loss of heterozygosity and homozygous deletions on 9p21-22 in melanoma.

Recent studies have implicated chromosome 9p21-22 as a location for a gene involved in cutaneous melanoma (CM). Deletion mapping in 35 matched tumour-constitutional DNA pairs from metastatic melanomas (including one melanoma cell line) and one dysplastic naevus has been performed using six short tandem repeat polymorphic (STRP) markers (D9S157-D9S162-IFNA-D9S171-DS9126-D9S10 4 ) which span approximately 19 cM across the 9p21-22 region. Both heterozygous and homozygous deletions were observed across the region in melanomas from both sporadic and familial cases. Overall 57% (20/35) of the samples displayed some form of loss. A deletion map identifies two areas of common loss either side of the interferon gene cluster. Familial CM has previously been shown to link to the more proximal of these regions. The deleted region distal to IFNA has not been previously described in melanoma. The results imply the involvement of more than one tumour suppressor gene on 9p in CM.

Differential expression of p16INK4a and p16beta transcripts in B-lymphoblastoid cells from members of hereditary melanoma families without CDKN2A exon mutations.

Mutations in the CDKN2A (p16INK4a) tumour suppressor gene on chromosome 9p21 are associated with inherited predisposition to melanoma, yet some 9p-linking hereditary melanoma families show no mutations in this gene. Splicing of CDKN2A exons 2 and 3 to an alternative first exon produces a transcript (p16beta) encoding a protein with cell cycle regulatory properties. We have analysed allele-specific expression levels of both the p16INK4a and p16beta transcripts in B-lymphoblastoid cells from 18 members of hereditary melanoma kindreds including four unrelated control individuals. In 15 of the 18 individuals examined, steady-state levels of each transcript either originated equally from each parental chromosome, or one parental chromosome was dominant for both transcripts. However, in three affected members of two 9p-linking hereditary melanoma kindreds, without exonic CDKN2A mutations, this pattern of coordinate expression was disrupted. In these individuals there was underexpression of the p16beta transcript, relative to the p16INK4a transcript, from the chromosome segregating with disease susceptibility. Loss of coordinate expression of the p16INK4a and p16beta transcripts may be an alternative genetic basis for melanoma susceptibility in certain 9p-linking kindreds.

Analysis of the p16 gene, CDKN2, in 17 Australian melanoma kindreds.

CDKN2 has been implicated as a melanoma susceptibility gene in some kindreds with a family history of this disease. Mutation analysis of CDKN2 in 17 familial melanoma Australian kindreds revealed a paucity of exon mutations and none of the previously described disease-related mutations. One novel germline mutation was found in exon one, Arg24Pro, which segregates with melanoma in 1/17 kindreds. Two previously described polymorphisms, Ala148Thr and a base change at nucleotide 540 were detected and one novel polymorphism in the untranslated region of exon 3 (nucleotide 580) was also found. Together with other recent reports, these findings provide support for CDKN2 as a susceptibility locus for familial melanoma but suggest that other loci are involved in some hereditary melanoma kindreds.