[Show abstract][Hide abstract] ABSTRACT: NRAS and BRAF mutations in melanoma inform current treatment paradigms but their role in survival from primary melanoma has not been established. Identification of patients at high risk of melanoma-related death based on their primary melanoma characteristics before evidence of recurrence could inform recommendations for patient follow-up and eligibility for adjuvant trials.
To determine tumor characteristics and survival from primary melanoma by somatic NRAS and BRAF status.
A population-based study with median follow-up of 7.6 years for 912 patients with first primary cutaneous melanoma analyzed for NRAS and BRAF mutations diagnosed in the year 2000 from the United States and Australia in the Genes, Environment and Melanoma Study and followed through 2007.
Tumor characteristics and melanoma-specific survival of primary melanoma by NRAS and BRAF mutational status.
The melanomas were 13% NRAS+, 30% BRAF+, and 57% with neither NRAS nor BRAF mutation (wildtype). In a multivariable model including clinicopathologic characteristics, NRAS+ melanoma was associated (P<.05) with mitoses, lower tumor infiltrating lymphocyte (TIL) grade, and anatomic site other than scalp/neck and BRAF+ melanoma was associated with younger age, superficial spreading subtype, and mitoses, relative to wildtype melanoma. There was no significant difference in melanoma-specific survival for melanoma harboring mutations in NRAS (HR 1.7, 95% CI, 0.8-3.4) or BRAF (HR, 1.5, 95% CI, 0.8-2.9) compared to wildtype melanoma adjusted for age, sex, site, AJCC tumor stage, TIL grade, and study center. However, melanoma-specific survival was significantly poorer for higher risk (T2b or higher stage) tumors with NRAS (HR 2.9; 95% CI 1.1-7.7) or BRAF (HR 3.1; 95% CI 1.2-8.5) mutations but not for lower risk (T2a or lower) tumors (P=.65) adjusted for age, sex, site, AJCC tumor stage, TIL grade, and study center.
Lower TIL grade for NRAS+ melanoma suggests it has a more immunosuppressed microenvironment, which may impact its response to immunotherapies. Further, the approximately three-fold increased death rate for higher risk tumors harboring NRAS or BRAF mutations compared to wildtype melanomas after adjusting for other prognostic factors indicates that the prognostic implication of NRAS and BRAF mutations deserves further investigation, particularly in higher AJCC stage primary melanomas.
[Show abstract][Hide abstract] ABSTRACT: Variation in the melanocortin-1receptor (MC1R) gene is associated with pigmentary phenotypes and risk of malignant melanoma. Few studies have reported on MC1R variation with respect to tumor characteristics, especially clinically important prognostic features. We examined associations between MC1R variants and histopathological melanoma characteristics. Study participants were enrolled from nine geographic regions in Australia, Canada, Italy and the United States and were genotyped for MC1R variants classified as high-risk [R] (D84E, R142H, R151C, R160W, and D294H, all nonsense and insertion/deletion) or low-risk [r] (all other nonsynonymous) variants. Tissue was available for 2,160 white participants of the Genes, Environment and Melanoma (GEM) Study with a first incident primary melanoma diagnosis, and underwent centralized pathologic review. No statistically significant associations were observed between MC1R variants and AJCC established prognostic tumor characteristics: Breslow thickness, presence of mitoses or presence of ulceration. However, MC1R was significantly associated with anatomic site of melanoma (p = 0.002) and a positive association was observed between carriage of more than one [R] variant and melanomas arising on the arms (OR = 2.39; 95% CI: 1.40, 4.09). We also observed statistically significant differences between sun-sensitive and sun-resistant individuals with respect to associations between MC1R genotype and AJCC prognostic tumor characteristics. Our results suggest inherited variation in MC1R may play an influential role in anatomic site presentation of melanomas and may differ with respect to skin pigmentation phenotype.
PLoS ONE 03/2015; 10(3):e0119920. DOI:10.1371/journal.pone.0119920 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Importance
Previous studies have reported that histopathologically amelanotic melanoma is associated with poorer survival than pigmented melanoma; however, small numbers of amelanotic melanomas, selected populations, lack of centralized pathologic review, or no adjustment for stage limit the interpretation or generalization of results from prior studies.Objective
To compare melanoma-specific survival between patients with histopathologically amelanotic and those with pigmented melanoma in a large international population-based study.Design, Setting, and Participants
Survival analysis with a median follow-up of 7.6 years. The study population comprised 2995 patients with 3486 invasive primary melanomas centrally scored for histologic pigmentation from the Genes, Environment, and Melanoma (GEM) Study, which enrolled incident cases of melanoma diagnosed in 1998 through 2003 from international population-based cancer registries.Main Outcomes and Measures
Clinicopathologic predictors and melanoma-specific survival of histologically amelanotic and pigmented melanoma were compared using generalized estimating equations and Cox regression models, respectively.Results
Of 3467 melanomas, 275 (8%) were histopathologically amelanotic. Female sex, nodular and unclassified or other histologic subtypes, increased Breslow thickness, presence of mitoses, severe solar elastosis, and lack of a coexisting nevus were independently associated with amelanotic melanoma (each P < .05). Amelanotic melanoma was generally of a higher American Joint Committee on Cancer (AJCC) tumor stage at diagnosis (odds ratios [ORs] [95% CIs] between 2.9 [1.8-4.6] and 11.1 [5.8-21.2] for tumor stages between T1b and T3b and ORs [95% CIs] of 24.6 [13.6-44.4] for T4a and 29.1 [15.5-54.9] for T4b relative to T1a; P value for trend, <.001) than pigmented melanoma. Hazard of death from melanoma was higher for amelanotic than for pigmented melanoma (hazard ratio [HR], 2.0; 95% CI, 1.4-3.0) (P < .001), adjusted for age, sex, anatomic site, and study design variables, but survival did not differ once AJCC tumor stage was also taken into account (HR, 0.8; 95% CI, 0.5-1.2) (P = .36).Conclusions and Relevance
At the population level, survival after diagnosis of amelanotic melanoma is poorer than after pigmented melanoma because of its more advanced stage at diagnosis. It is probable that amelanotic melanomas present at more advanced tumor stages because they are difficult to diagnose. The association of amelanotic melanoma with presence of mitoses independently of Breslow thickness and other clinicopathologic characteristics suggests that amelanotic melanomas might also grow faster than pigmented melanomas. New strategies for early diagnosis and investigation of the biological properties of amelanotic melanoma are warranted.
[Show abstract][Hide abstract] ABSTRACT: Background We previously reported a significant association between higher ultraviolet radiation exposure before diagnosis and greater survival with melanoma in a population-based study in Connecticut. We sought to evaluate the hypothesis that sun exposure prior to diagnosis was associated with greater survival in a larger, international population-based study with more detailed exposure information. Methods We conducted a multi-center, international population-based study in four countries - Australia, Italy, Canada and the United States - with 3,578 cases of melanoma with an average of 7.4 years of follow-up. Measures of sun exposure included sunburn, intermittent exposure, hours of holiday sun exposure, hours of water-related outdoor activities, ambient UVB dose, histological solar elastosis and season of diagnosis. Results Results were not strongly supportive of the earlier hypothesis. Having had any sunburn in one year within 10 years of diagnosis was inversely associated with survival; solar elastosis - a measure of lifetime cumulative exposure - was not. Additionally, none of the intermittent exposure measures - water related activities and sunny holidays - were associated with melanoma-specific survival. Estimated ambient UVB dose was not associated with survival. Conclusion Although there was an apparent protective effect of sunburns within 10 years of diagnosis, there was only weak evidence in this large, international, population-based study of melanoma that sun exposure prior to diagnosis is associated with greater melanoma-specific survival. Impact This study adds to the evidence that sun exposure prior to melanoma diagnosis has little effect on survival with melanoma.
[Show abstract][Hide abstract] ABSTRACT: A rare germline variant in the microphthalmia-associated transcription factor (MITF) gene, E318K, has been reported as associated with melanoma. We confirmed its independent association with melanoma [odds ratio (OR) 1.7, 95% confidence interval (CI) = 1.1, 2.7, P = 0.03]; adjusted for age, sex, center, age × sex interaction, pigmentation characteristics, family history of melanoma, and nevus density). In stratified analyses, carriage of MITF E318K was associated with melanoma more strongly in people with dark hair than fair hair (P for interaction, 0.03) and in those with no moles than some or many moles (P for interaction, <0.01). There was no evidence of interaction between MC1R 'red hair variants' and MITF E318K. Moreover, risk of melanoma among carriers with 'low risk' phenotypes was as great or greater than among those with 'at risk' phenotypes with few exceptions.
[Show abstract][Hide abstract] ABSTRACT: Although most hospital-based studies suggest more favorable survival with tumor-infiltrating lymphocytes (TILs) present in primary melanomas, it is uncertain whether TILs provide prognostic information beyond existing melanoma staging definitions. We addressed the issue in an international population-based study of patients with single and multiple primary melanomas.
On the basis of the Genes, Environment and Melanoma (GEM) study, we conducted follow-up of 2,845 patients diagnosed from 1998 to 2003 with 3,330 invasive primary melanomas centrally reviewed for TIL grade (absent, nonbrisk, or brisk). The odds of TIL grades associated with clinicopathologic features and survival by TIL grade were examined.
Independent predictors (P < .05) for nonbrisk TIL grade were site, histologic subtype, and Breslow thickness, and for brisk TIL grade, they were age, site, Breslow thickness, and radial growth phase. Nonbrisk and brisk TIL grades were each associated with lower American Joint Committee on Cancer (AJCC) tumor stage compared with TIL absence (Ptrend < .001). Death as a result of melanoma was 30% less with nonbrisk TIL grade (hazard ratio [HR], 0.7; 95% CI, 0.5 to 1.0) and 50% less with brisk TIL grade (HR, 0.5; 95% CI, 0.3 to 0.9) relative to TIL absence, adjusted for age, sex, site, and AJCC tumor stage.
At the population level, higher TIL grade of primary melanoma is associated with a lower risk of death as a result of melanoma independently of tumor characteristics currently used for AJCC tumor stage. We conclude that TIL grade deserves further prospective investigation to determine whether it should be included in future AJCC staging revisions.
[Show abstract][Hide abstract] ABSTRACT: IMPORTANCE Little is known about survival after a diagnosis of a second or higher-order (multiple) primary melanoma, and no study has explored survival in a population-based sample that included patients with single primary melanomas (SPMs) and multiple primary melanomas (MPMs) of any stage. Because people with a first primary melanoma are known to have an increased risk of being diagnosed with another, evidence for prognosis is needed. OBJECTIVE To determine whether survival after diagnosis was better in patients with MPMs than with SPMs, as suggested in a recent study. DESIGN Survival analysis with median follow-up of 7.6 (range, 0.4-10.6) years. SETTING The Genes, Environment, and Melanoma Study enrolled incident cases of melanoma from population-based cancer registries in Australia, Canada, Italy, and the United States. Multiple primary melanomas were ascertained during a longer period than SPM. PARTICIPANTS Two thousand three hundred seventy-two patients with SPM and 1206 with MPM. EXPOSURE Diagnosis with melanoma. MAIN OUTCOMES AND MEASURES Melanoma-specific fatality hazard ratios (HR) and 95% confidence intervals associated with clinical and pathological characteristics of SPM, MPM, and both in Cox proportional hazards regression models. RESULTS Melanoma thickness was the main determinant of fatality (HR for >4 mm, 7.68 [95% CI, 4.46-13.23]); other independent predictors were ulceration, mitoses, and scalp location. After adjustment for these other predictors, we found little difference in fatality between MPM and SPM (HR for MPM relative to SPM, 1.24 [95% CI, 0.91-1.69; P = .18]). Thicker SPM, however, had higher fatality (HR for >4 mm, 13.56 [95% CI, 6.47-28.40]) than thicker MPM (2.93 [1.17-7.30]). CONCLUSIONS AND RELEVANCE Although overall fatalities due to SPM and MPM were similar, relative fatality for thicker SPM was greater than that for thicker MPM. This finding may offer support for a difference in outcome between patients with SPM and MPM related to factors other than closer surveillance and earlier diagnosis. The better outcomes are worth further exploration.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to quantify the risk of cancers other than melanoma among family members of CDKN2A mutation carriers using data from the Genes, Environment and Melanoma study. Relative risks (RRs) of all non-melanoma cancers among first-degree relatives (FDRs) of melanoma patients with CDKN2A mutations (n = 65) and FDRs of melanoma patients without mutations (n = 3537) were calculated as the ratio of estimated event rates (number of cancers/total person-years) in FDRs of carriers vs noncarriers with exact Clopper-Pearson-type tests and 95% confidence intervals (CIs). All statistical tests were two-sided. There were 56 (13.1%) non-melanoma cancers reported among 429 FDRs of mutation carriers and 2199 (9.4%) non-melanoma cancers in 23 452 FDRs of noncarriers. The FDRs of carriers had an increased risk of any cancer other than melanoma (56 cancers among 429 FDRs of carrier probands vs 2199 cancers among 23 452 FDRs of noncarrier probands; RR = 1.5, 95% CI = 1.2 to 2.0, P = .005), gastrointestinal cancer (20 cancers among 429 FDRs of carrier probands vs 506 cancers among 23 452 FDRs of noncarrier probands; RR = 2.4, 95% CI = 1.4 to 3.7, P = .001), and pancreatic cancer (five cancers among 429 FDRs of carrier probands vs 41 cancers among 23 452 FDRs of noncarrier probands; RR = 7.4, 95% CI = 2.3 to 18.7, P = .002). Wilms tumor was reported in two FDRs of carrier probands and three FDRs of noncarrier probands (RR = 40.4, 95% CI = 3.4 to 352.7, P = .005). The lifetime risk of any cancer other than melanoma among CDKN2A mutation carriers was estimated as 59.0% by age 85 years (95% CI = 39.0% to 75.4%) by the kin-cohort method, under the standard assumptions of Mendelian genetics on the genotype distribution of FDRs conditional on proband genotype.
Journal of the National Cancer Institute 04/2012; 104(12):953-6. DOI:10.1093/jnci/djs221 · 12.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 0.6-12.7% of patients with primary cutaneous melanoma will develop additional melanomas. Pathologic features of tumors in patients with multiple primary cutaneous melanomas have not been well described. In this large, international, multicenter, case-control study, we compared the clinicopathologic features of a subsequent melanoma with the preceding (usually the first) melanoma in patients with multiple primary cutaneous melanomas, and with those of melanomas in patients with single primary cutaneous melanomas.
Multiple primary melanoma (cases) and single primary invasive melanoma (controls) patients from the Genes, Environment and Melanoma (GEM) study were included if their tumors were available for pathologic review and confirmed as melanoma. Clinicopathologic characteristics of invasive subsequent and first melanomas in cases and invasive single melanomas in controls were compared.
A total of 473 pairs comprising a subsequent and a first melanoma and 1,989 single melanomas were reviewed. Forward stepwise regression modeling in 395 pairs with complete data showed that, compared with first melanomas, subsequent melanomas were more commonly contiguous with a dysplastic nevus, more prevalent on the head/neck and legs than other sites, and thinner. Compared with single primary melanomas, subsequent melanomas were more likely to be associated with a contiguous dysplastic nevus, more prevalent on the head/neck and legs, and thinner. The same differences were observed when subsequent melanomas were compared with single melanomas. First melanomas were more likely than single melanomas to have associated solar elastosis and no observed mitoses.
Thinner subsequent than first melanomas suggest earlier diagnosis, perhaps due to closer clinical scrutiny. The association of subsequent melanomas with dysplastic nevi is consistent with the latter being risk factors or risk markers for melanoma.
[Show abstract][Hide abstract] ABSTRACT: The vitamin D receptor (VDR) gene has been associated with cancer risk, but only a few polymorphisms have been studied in relation to melanoma risk and the results have been inconsistent. We examined 38 VDR gene single nucleotide polymorphisms (SNPs) in a large international multicenter population-based case-control study of melanoma. Buccal DNAs were obtained from 1,207 people with incident multiple primary melanoma and 2,469 with incident single primary melanoma. SNPs with known or suspected impact on VDR activity, haplotype tagging SNPs with ≥ 10% minor allele frequency in Caucasians, and SNPs reported as significant in other association studies were examined. Logistic regression was used to calculate the relative risks conferred by the individual SNP. Eight of 38 SNPs in the promoter, coding, and 3' gene regions were individually significantly associated with multiple primary melanoma after adjusting for covariates. The estimated increase in risk for individuals who were homozygous for the minor allele ranged from 25 to 33% for six polymorphisms: rs10875712 (odds ratios [OR] 1.28; 95% confidence interval (CI), 1.01-1.62), rs4760674 (OR 1.33; 95% CI, 1.06-1.67), rs7139166 (OR 1.26; 95%CI, 1.02-1.56), rs4516035 (OR 1.25; 95%CI, 1.01-1.55), rs11168287 (OR 1.27; 95%CI, 1.03-1.57) and rs1544410 (OR 1.30; 95%CI, 1.04-1.63); for two polymorphisms, homozygous carriers had a decreased risk: rs7305032 (OR 0.81; 95%CI 0.65-1.02) and rs7965281 (OR, 0.78; 95%CI, 0.62-0.99). We recognize the potential false positive findings because of multiple comparisons; however, the eight significant SNPs in our study outnumbered the two significant tests expected to occur by chance. The VDR may play a role in melanomagenesis.
International Journal of Cancer 03/2011; 130(2):405-18. DOI:10.1002/ijc.26023 · 5.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure, although the associations of UV exposure and phenotype with solar elastosis are yet to be fully explored.
The study included 2,589 incident primary melanoma patients with assessment of histologic solar elastosis in the population-based Genes, Environment, and Melanoma study. Ambient erythemal UV (UVE) at places of residence and sun exposure hours, including body site-specific exposure, were collected. We examined the association of cumulative site-specific and non-site-specific sun exposure hours and ambient UVE with solar elastosis in multivariable models adjusted for age, sex, center, pigmentary characteristics, nevi, and, where relevant, body site.
Solar elastosis was associated most strongly with site-specific UVE [odds ratio (OR) for top exposure quartile, 5.20; 95% confidence interval (95% CI), 3.40-7.96; P for trend <0.001] and also with site-specific sun exposure (OR for top quartile, 5.12; 95% CI, 3.35-7.83; P for trend <0.001). Older age (OR at >70 years, 7.69; 95% CI, 5.14-11.52; P for trend < 0.001) and having more than 10 back nevi (OR, 0.77; 95% CI, 0.61-0.97; P = 0.03) were independently associated with solar elastosis.
Solar elastosis had a strong association with higher site-specific UVE dose, older age, and fewer nevi.
Solar elastosis could be a useful biomarker of lifetime site-specific UV. Future research is needed to explore whether age represents more than simple accumulation of sun exposure and to determine why people with more nevi may be less prone to solar elastosis.
[Show abstract][Hide abstract] ABSTRACT: To assess whether lymphatic invasion identified by immunostaining with monoclonal antibody (Mab) D2-40 in primary cutaneous melanomas correlates with other clinicopathologic factors and to assess whether lymphatic invasion is a potential predictor of sentinel lymph node (SLN) status.
Retrospective case-series study.
Academic referral center. Patients Ninety-six consecutive patients with primary cutaneous melanomas 1 mm thick or greater with adequate pathologic material available for immunohistochemical studies and SLN biopsy.
Association between lymphatic invasion identified by immunostaining with Mab D2-40 in primary cutaneous melanoma and correlation with the clinicopathologic features and the association of all of the factors with SLN status.
Lymphatic invasion identified by immunostaining with Mab D2-40 was significantly associated with deeper Clark level of invasion (P < .001), and greater Breslow tumor thickness (P = .01) SLN positivity was identified in 23 of 96 cases (24%). At univariate analysis, younger age (P = .03), ulceration (P < .006), lymphatic invasion (P < .02), deeper Clark level of invasion (P < .008), Breslow tumor thickness (P = .008), and tumor site on the trunk (P = .02) were significantly associated with SLN metastases. At multivariate analysis, only younger age (P = .04), ulceration (P = .03), and lymphatic invasion detected by immunostaining with Mab D2-40 (P = .01) were significantly associated with SLN positivity. The probability of SLN positivity was 13% when all 3 independent prognostic factors yielded negative findings and increased to 61% when all 3 variables yielded positive findings.
Breslow tumor thickness, Clark level of invasion, and tumor site on the trunk predicted SLN status at univariate analysis. Multivariate regression analysis showed that lymphatic invasion identified by immunostaining with Mab D2-40, younger age, and ulceration were the only independent prognostic factors. The most significant predictor of SLN metastasis was the positivity of all 3 independent prognostic factors (61%). Findings of this study suggest that assessment of lymphatic invasion by immunostaining with Mab D2-40 with other clinicopathologic factors can be used to identify patients who could be spared the need for SLN biopsy.
Archives of dermatology 04/2008; 144(4):462-7. DOI:10.1001/archderm.144.4.462 · 4.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cyclin-dependent kinase inhibitor type 2A (CDKN2A) has been identified as a major melanoma susceptibility gene based on the presence of germline mutations in high-risk melanoma families. In this study, we sought to identify and characterize the spectrum of CDKN2A mutations affecting p16 inhibitor of cyclin-dependent kinase type 4 (INK4a) in individuals with melanoma using a population-based study design. DNA samples from 1189 individuals with incident multiple primary melanoma (MPM) and 2424 with incident single primary melanoma unselected for family history of melanoma were available for screening of CDKN2A (p16INK4a) mutations. Variants were classified for functional impact based on intragenic position, existing functional data, sequence, and structural analysis. The impact of individual mutations and functional groupings was assessed by comparing frequencies in cases of MPM versus cases with a single first primary melanoma, and by comparing the reported incidence rates in first-degree relatives. Our results show that mutations occur infrequently in these high-risk groups, and that they occur mainly in exons 1alpha and 2. Rare coding variants with putative functional impact are observed to increase substantially the risk of melanoma. With the exception of the variant in position -34 of CDKN2A of known functional consequence, the remaining rare variants in the non-coding region have no apparent impact on risk.
[Show abstract][Hide abstract] ABSTRACT: Sun exposure is the main cause of melanoma in populations of European origin. No previous study has examined the effect of sun exposure on risk of multiple primary melanomas compared with people who have one melanoma.
We identified and enrolled 2,023 people with a first primary melanoma (controls) and 1,125 with multiple primary melanomas (cases) in seven centers in four countries, recorded their residential history to assign ambient UV and interviewed them about their sun exposure.
Risk of multiple primary melanomas increased significantly (P<0.05) to OR=2.10 for the highest exposure quarter of ambient UV irradiance at birth and 10 years of age, to OR=1.38 for lifetime recreational sun exposure, to OR=1.85 for beach and waterside activities, to OR=1.57 for vacations in a sunnier climate, to OR=1.50 for sunburns. Occupational sun exposure did not increase risk (OR=1.03 for highest exposure). Recreational exposure at any age increased risk and appeared to add to risk from ambient UV in early life.
People who have had a melanoma can expect to reduce their risk of a further melanoma by reducing recreational sun exposure whatever their age. The same is probably true for a person who has never had a melanoma.
Cancer Causes and Control 05/2007; 18(3):295-304. DOI:10.1007/s10552-006-0091-x · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Natural variation in the coding region of the melanocortin-1 receptor (MC1R) gene is associated with constitutive pigmentation phenotypes and development of melanoma and nonmelanoma skin cancers. We investigated the effect of MC1R variants on melanoma using a large, international population-based study design with complete determination of all MC1R coding region variants. Direct sequencing was completed for 2,202 subjects with a single primary melanoma (controls) and 1,099 subjects with second or higher-order primary melanomas (cases) from Australia, the United States, Canada, and Italy. We observed 85 different MC1R variants, 10 of which occurred at a frequency >1%. Compared with controls, cases were more likely to carry two previously identified red hair ("R") variants [D84E, R151C, R160W, and D294H; odds ratio (OR), 1.6; 95% confidence interval (95% CI), 1.1-2.2]. This effect was similar among individuals carrying one R variant and one r variant (defined as any non-R MC1R variant; OR, 1.6; 95% CI, 1.3-2.2) and among those carrying only one R variant (OR, 1.5; 95% CI, 1.1-1.9). There was no statistically significant association among those carrying only one or two r variants. Effects were similar across geographic regions and categories of pigmentation characteristics or number of moles. Our results confirm that MC1R is a low-penetrance susceptibility locus for melanoma, show that pigmentation characteristics may not modify the relationship of MC1R variants and melanoma risk, and suggest that associations may be smaller than previously reported in part due to the study design.
Cancer Research 10/2006; 66(18):9330-7. DOI:10.1158/0008-5472.CAN-06-1634 · 9.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Germ-line mutations of CDKN2A have been identified as strong risk factors for melanoma in studies of multiple-case families. However, an assessment of their relative risk for melanoma in the general population has been difficult because they occur infrequently. We addressed this issue using a novel population-based case-control study design in which "cases" have incident second- or higher-order melanomas [multiple primary melanoma (MPM)] and "controls" have incident first primary melanoma [single primary melanoma (SPM)]. Participants were ascertained from nine geographic regions in Australia, Canada, Italy, and United States. In the 1,189 MPM cases and 2,424 SPM controls who were eligible and available for analysis, the relative risk of a subsequent melanoma among patients with functional mutations who have an existing diagnosis of melanoma, after adjustments for age, sex, center, and known phenotypic risk factors, is estimated to be 4.3 (95% confidence interval, 2.3-7.7). The odds ratio varied significantly depending on the type of mutation involved. The results suggest that the relative risk of mutation carriers in the population may be lower than currently believed and that different mutations on the CDKN2A gene may confer substantially different risks of melanoma.
[Show abstract][Hide abstract] ABSTRACT: The population-based case-control study is not suited to the evaluation of rare genetic (or environmental) factors. The use of a novel case-control design in which cases have second primaries and controls are cancer survivors has been proposed for this purpose.
We report results from an international study of melanoma that involved population-based ascertainment of incident cases of second or subsequent primary melanoma as the 'case' group and incident cases of first primary melanoma as the 'control' group. We evaluate the validity of the study design by comparing the results obtained for phenotypic factors that have been shown consistently to be associated with melanoma in previous conventional studies with the results from a conventional case-control study conducted in Connecticut and from literature reviews.
All but one of the known risk factors for melanoma were shown to be significantly associated with melanoma in our study, though the individual odds ratios appear to be somewhat attenuated relative to the magnitudes typically observed in the literature.
Patients with a second or subsequent primary cancer of a single type represent a potentially valuable and under-utilized resource for the study of cancer aetiology.
International Journal of Epidemiology 07/2006; 35(3):756-64. DOI:10.1093/ije/dyl044 · 9.18 Impact Factor