Acute leukemia is the most common cancer in children under 15 years of age; 80%
are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood
leukemia shows further diversity based on cytogenetic and molecular characteristics, which may
relate to distinct etiologies. Case–control studies conducted worldwide, particularly of
ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens.
There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several
environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other
complex diseases, is likely to be influenced both by independent and interactive effects of genes
and environmental exposures. While some studies have analyzed the role of genetic variants, few have
been sufficiently powered to investigate gene–environment interactions.
The Childhood Leukemia International Consortium (CLIC) was established in 2007 to promote
investigations of rarer exposures, gene–environment interactions and subtype-specific
associations through the pooling of data from independent studies.
By September 2012, CLIC included 22 studies (recruitment period: 1962–present)
from 12 countries, totaling approximately 31 000 cases and 50 000 controls. Of these, 19
case–control studies have collected detailed epidemiologic data, and DNA samples have been
collected from children and child–parent trios in 15 and 13 of these studies, respectively.
Two registry-based studies and one study comprising hospital records routinely obtained at birth
and/or diagnosis have limited interview data or biospecimens.
CLIC provides a unique opportunity to fill gaps in knowledge about the role of
environmental and genetic risk factors, critical windows of exposure, the effects of
gene–environment interactions and associations among specific leukemia subtypes in different
Leukemia; Children; Consortium; Epidemiology; Genetics
Studies of smoking and risk of non-Hodgkin lymphoma (NHL) have yielded inconsistent results, possibly due to subtype heterogeneity and/or genetic variation impacting the metabolism of tobacco-derived carcinogens, including substrates of the N-acetyltransferase enzymes NAT1 and NAT2.
We conducted a pooled analysis of 5,026 NHL cases and 4,630 controls from seven case–control studies in the international lymphoma epidemiology consortium to examine associations between smoking, variation in the N-acetyltransferase genes NAT1 and NAT2, and risk of NHL subtypes. Smoking data were harmonized across studies, and genetic variants in NAT1 and NAT2 were used to infer acetylation phenotype of the NAT1 and NAT2 enzymes, respectively. Pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for risk of NHL and subtypes were calculated using joint fixed effects unconditional logistic regression models.
Current smoking was associated with a significant 30 % increased risk of follicular lymphoma (n = 1,176) but not NHL overall or other NHL subtypes. The association was similar among NAT2 slow (OR 1.36; 95 % CI 1.07–1.75) and intermediate/rapid (OR 1.27; 95 % CI 0.95–1.69) acetylators (pinteraction = 0.82) and also did not differ by NAT1*10 allelotype. Neither NAT2 phenotype nor NAT1*10 allelotype was associated with risk of NHL overall or NHL subtypes.
The current findings provide further evidence for a modest association between current smoking and follicular lymphoma risk and suggest that this association may not be influenced by variation in the N-acetyltransferase enzymes.
Non-Hodgkin lymphoma; Gene environment interaction; Cigarette smoking; N-acetyltransferase; Follicular lymphoma
Cervical screening is currently recommended every two years in sexually active women aged 18-20 to 69 years in Australia. Direct replacement of conventional cytology with liquid-based cytology (LBC) for cervical screening was rejected for public funding on grounds of cost-effectiveness, first in 2002 and again in 2009, but LBC is performed as an adjunct to conventional cytology in women who elect to pay. The objective of this study was to describe prevalence and predictors of use of LBC in Australia’s most populous state, New South Wales (NSW).
We performed cross-sectional and population-based cohort analyses using data from the state Pap Test Register in NSW. We calculated the age-adjusted proportion of women aged 20-69 years electing to have adjunctive LBC over the period from 2006-2010. We also calculated the fully-adjusted odds ratios for the association between subsequent LBC use and age, socioeconomic status, place of residence, previous cytological history and provider type in a cohort of 360,247 women who had an index cervical cytology test in 2006–8.
Uptake of LBC varied between 29.7% (95% Confidence Interval (CI): 29.5-30.0%) in 2006/7 and 26.6% (95% CI: 26.4-26.9%) in 2009/10. LBC was more likely to be used in women aged 30-44 years, if it had been used previously (OR13.58, 95% CI: 13.33-13.84), if the previous test result was abnormal (OR2.62, 95% CI:2.53-2.72) or unsatisfactory (OR2.37, 95% CI:2.27-3.47), or if a gynaecologist requested the test (OR1.50, 95% CI:1.46-1.54). Uptake was least for women in remote/very remote areas (OR0.68; 95% CI:0.57-0.80 referenced to those in major cities) and in lower socioeconomic groups (OR 0.41, 95% CI:0.40-0.42 for lowest versus highest SES quintile).
In the current environment in NSW, Australia, in which public funding for LBC has not been available, adjunctive uptake of LBC depends strongly on a woman’s age, her screening history and socioeconomic factors. These findings provide important context for a current review of technologies used in the National Cervical Screening Program in Australia.
Cervical screening; Cervical cytology; Pap smear; Liquid based cytology; Australia
Little is known about survival after a diagnosis of a second or higher order (multiple) primary melanoma. We aimed to determine whether survival after diagnosis was better in patients with multiple primary melanomas (MPM) than with single primary melanomas (SPM), as suggested in a recent study.
Survival analysis with median follow-up of 7.6 years (range 0.4-10.6).
The Genes, Environment and Melanoma (GEM) study enrolled incident cases of melanoma notified to population-based cancer registries in Australia, Canada, Italy and the USA. MPM were ascertained over a longer period than SPM.
2372 patients with SPM and 1206 with MPM.
Main outcome measures
Melanoma-specific fatality hazard ratios (HR) and confidence intervals (CI) associated with clinical and pathologic characteristics of SPM, MPM and both together in Cox regression models.
Thickness was the main determinant of fatality (HR for >4mm=7.68, 95% CI 4.46 to 13.23); other independent predictors were ulceration, mitoses and scalp location. After adjustment for these other predictors, there was little difference in fatality between MPM and SPM (HR for MPM relative to SPM=1.24, 95% CI 0.91 to 1.69; P = .18). Thicker SPM, however, had higher fatality (HR for >4mm=13.56, 95% CI 6.47-28.40) than thicker MPM (HR for >4mm=2.93, 95% CI 1.17-7.30).
While overall fatalities from SPM and MPM were similar, relative fatality for thick SPM was greater than for thick MPM. This finding may offer support for a difference in outcome between patients with SPM and MPM that is worth further exploration.
GEM; MPM; SPM; pathology characteristics; fatality; survival
Cancer is a serious health issue in China, but accurate national counts for cancer incidence are not currently available. Knowledge of the cancer burden is necessary for national cancer control planning. In this study, national death survey data and cancer registration data were used to calculate the cancer burden in China using a Bayesian approach.
Cancer mortality and incidence rates for 2004–2005 were obtained from the National Cancer Registration database. The third National Death Survey (NDS), 2004–2005 database provided nationally representative cancer mortality rates. Bayesian modeling methods were used to estimate mortality to incidence (MI) ratios from the registry data and national incidence from the NDS for specific cancer types by age, sex and urban or rural location.
The total estimated incident cancer cases in 2005 were 2,956,300 (1,762,000 males, 1,194,300 females). World age standardized incidence rates were 236.2 per 100,000 in males and 168.9 per 100,000 in females in urban areas and 203.7 per 100,000 and 121.8 per 100,000 in rural areas.
MI ratios are useful for estimating national cancer incidence in the absence of representative incidence or survival data. Bayesian methods provide a flexible framework for smoothing rates and representing statistical uncertainty in the MI ratios. Expansion of China’s cancer registration network to be more representative of the country would improve the accuracy of cancer burden estimates.
Bayes Theorem; China; Incidence; Mortality; Neoplasm
Melanocortin-1 receptor (MC1R) gene variants are very common and are associated with melanoma risk, but their contribution to melanoma risk prediction compared with traditional risk factors is unknown. We aimed to 1) evaluate the separate and incremental contribution of MC1R genotype to prediction of early-onset melanoma, and compare this with the contributions of physician-measured and self-reported traditional risk factors, and 2) develop risk prediction models that include MC1R, and externally validate these models using an independent dataset from a genetically similar melanoma population.
Using data from an Australian population-based, case-control-family study, we included 413 case and 263 control participants with sequenced MC1R genotype, clinical skin examination and detailed questionnaire. We used unconditional logistic regression to estimate predicted probabilities of melanoma. Results were externally validated using data from a similar study in England.
When added to a base multivariate model containing only demographic factors, MC1R genotype improved the area under the receiver operating characteristic curve (AUC) by 6% (from 0.67 to 0.73; P < 0.001) and improved the quartile classification by a net 26% of participants. In a more extensive multivariate model, the factors that contributed significantly to the AUC were MC1R genotype, number of nevi and previous non-melanoma skin cancer; the AUC was 0.78 (95% CI 0.75-0.82) for the model with self-reported nevi and 0.83 (95% CI 0.80-0.86) for the model with physician-counted nevi. Factors that did not further contribute were sun and sunbed exposure and pigmentation characteristics. Adding MC1R to a model containing pigmentation characteristics and other self-reported risk factors increased the AUC by 2.1% (P = 0.01) and improved the quartile classification by a net 10% (95% CI 1-18%, P = 0.03).
Although MC1R genotype is strongly associated with skin and hair phenotype, it was a better predictor of early-onset melanoma than was pigmentation characteristics. Physician-measured nevi and previous non-melanoma skin cancer were also strong predictors. There might be modest benefit to measuring MC1R genotype for risk prediction even if information about traditional self-reported or clinically measured pigmentation characteristics and nevi is already available.
MC1R; Risk prediction; Accuracy; Melanoma; Sun exposure; Early-onset; Pigmentation; Nevi
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.
Participation in epidemiological studies has fallen significantly over the past 30 years; this has been attributed to a busier lifestyle and longer working hours. In case–control studies, participation among cases is usually higher than among controls due to the personal relevance. In Australia, between 2003 and 2011, we conducted three national population-based case–control studies of risk factors for childhood cancers; brain tumors, acute leukemia and neuroblastoma and Wilms’ tumor. In this sub-study, we aimed to investigate factors that may have influenced study participation and completeness of survey completion.
The proportion of incident cases that were eligible to participate was lowest in the brain tumor study (Aus-CBT) (83.1%), as was the proportion of eligible families that consented (57%). The percentage of eligible cases that consented was highest in the leukemia study (Aus-ALL) (80.2%). The mode of invitation used was associated with families’ consent in each of the studies. Families invited in person, at clinic appointments, were more likely to consent than families invited by letter or phone. Timing of invitation following the child’s diagnosis differed among studies but, the likelihood of consent did not appear to be directly related to this. The return of questionnaires, completion of interview, and provision of DNA (blood sample) was highest in Aus-ALL (93%) and lowest in Aus-CBT (81%).
Studies of childhood cancer, and possibly other childhood diseases, should arrange for the family to be invited in person and, where possible, by a doctor with whom they are familiar. Whilst telephone interviews are time consuming and costly, particularly for large studies, they should be preferred over questionnaires for obtaining complete data.
Recruitment; Pediatric cancer; Study invitation; Participation; Questionnaire
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 multi-center 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.
473 pairs comprising a subsequent and a first melanoma and 1989 single melanomas were reviewed. Forward stepwise regression modeling in 395 pairs with complete data showed that, compared to 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 also 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.
Diagnosis; Melanoma; Multiple primary melanoma; Pathology; Risk factors
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 SNPs in a large international multi-center population-based case-control study of melanoma.
Buccal DNAs were obtained from 1207 people with incident multiple primary melanoma and 2469 with incident single primary melanoma. SNPs with known or suspected impact on VDR activity, htSNPs with ≥10% MAF 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 6 polymorphisms: rs10875712 (OR 1.28; 95%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), rs1544410 (OR 1.30; 95%CI, 1.04–1.63); for 2 polymorphisms, homozygous carriers had a decreased risk: rs7305032 (OR 0.81; 95%CI 0.65–1.02), rs7965281 (OR, 0.78; 95%CI, 0.62–0.99). We recognize the potential false positive findings due to multiple comparisons; however the 8 significant SNPs in this study outnumbered the 2 significant tests expected to occur by chance. The vitamin D receptor may play a role in melanomagenesis.
VDR; SNP; melanoma; polymorphism; vitamin D
Background: There is little information on the detailed patterns of cervical screening uptake in older migrant women in Australia. This linkage study was performed to assess cervical screening participation in older migrants.
Methods: We linked year 2000-2001 records for 14,228 Middle Eastern/Asian-born women 40-64 years of age, and an age and area matched random sample of 13,939 Australian-born women in the New South Wales (NSW) Admitted Patients Data Collection (APDC), which records country of birth, to screening register records. Screening behaviour after 1st July 2001 was assessed in women without a recorded prior cervical abnormality
Results: Compared to Australian-born women, women born in South Central Asia had a lower screening participation rate (odds ratio for being screened at least once within a 3 year period 0.78, 95% CI 0.70-0.88). However, participation appeared relatively higher (17%-25%) in women born in the Middle East or other parts of Asia. Screening increased with increasing socioeconomic status (SES) in Australian-born women, but this trend was not observed in the migrant women. When we broadly corrected for hysterectomy, the apparent excess of screening in women from the Middle East and other parts of Asia was substantially eliminated and in contrast, the apparent deficiency in screening in women from South Central Asia increased.
Conclusions: Older women from the Middle East, and North East and South East Asian countries appeared to have similar overall screening participation to that of Australian-born women. Women from South Central Asia appeared less likely than Australian-born women to participate in cervical screening at the recommended interval.
Cervical cancer; Cervical screening; Record linkage; Screening in migrants
Sunlight exposure increases risk of melanoma. Sunlight also potentiates cutaneous synthesis of vitamin D, which can inhibit melanoma cell growth and promote apoptosis. Vitamin D effects are mediated through the vitamin D receptor (VDR). We hypothesized that genetic variation in VDR affects the relationship of sun exposure to risk of a further melanoma in people who have already had one.
We investigated the interaction between VDR polymorphisms and sun exposure in a population-based multinational study comparing 1138 patients with a multiple (second or subsequent) primary melanoma (cases) to 2151 patients with a first primary melanoma (controls); essentially a case-control study of melanoma in a population of melanoma survivors. Sun exposure was assessed using a questionnaire and interview, and was shown to be associated with multiple primary melanoma. VDR was genotyped at the FokI and BsmI loci and the main effects of variants at these loci and their interactions with sun exposure were analyzed.
Only the BsmI variant was associated with multiple primary melanoma (OR = 1.27, 95% CI 0.99-1.62 for the homozygous variant genotype). Joint effects analyses showed highest ORs in the high exposure, homozygous variant BsmI genotype category for each sun exposure variable. Stratified analyses showed somewhat higher ORs for the homozygous BsmI variant genotype in people with high sun exposure than with low sun exposure. P values for interaction, however, were high.
These results suggest that risk of multiple primary melanoma is increased in people who have the BsmI variant of VDR.
melanoma; FokI; BsmI; sun exposure
Monitoring treatment patterns is crucial to improving cancer patient care. Our aim was to determine the accuracy of linked routinely collected administrative health data for monitoring colorectal and lung cancer care in New South Wales (NSW), Australia.
Colorectal and lung cancer cases diagnosed in NSW between 2000 and 2002 were identified from the NSW Central Cancer Registry (CCR) and linked to their hospital discharge records in the NSW Admitted Patient Data Collection (APDC). These records were then linked to data from two relevant population-based patterns of care surveys. The main outcome measures were the sensitivity and specificity of data from the CCR and APDC for disease staging, investigative procedures, curative surgery, chemotherapy, radiotherapy, and selected comorbidities.
Data for 2917 colorectal and 1580 lung cancer cases were analysed. Unknown disease stage was more common for lung cancer in the administrative data (18%) than in the survey (2%). Colonoscopies were captured reasonably accurately in the administrative data compared with the surveys (82% and 79% respectively; 91% sensitivity, 53% specificity) but all other colorectal or lung cancer diagnostic procedures were under-enumerated. Ninety-one percent of colorectal cancer cases had potentially curative surgery recorded in the administrative data compared to 95% in the survey (96% sensitivity, 92% specificity), with similar accuracy for lung cancer (16% and 17%; 92% sensitivity, 99% specificity). Chemotherapy (~40% sensitivity) and radiotherapy (sensitivity≤30%) were vastly under-enumerated in the administrative data. The only comorbidity that was recorded reasonably accurately in the administrative data was diabetes.
Linked routinely collected administrative health data provided reasonably accurate information on potentially curative surgical treatment, colonoscopies and comorbidities such as diabetes. Other diagnostic procedures, comorbidities, chemotherapy and radiotherapy were not well enumerated in the administrative data. Other sources of data will be required to comprehensively monitor the primary management of cancer patients.
Linked data; Validation; Colorectal cancer; Lung cancer; Investigative procedures; Disease stage; Surgery; Chemotherapy; Radiotherapy; Comorbidities
Organised cervical screening, introduced in 1991, appears to have reduced rates of cervical cancer incidence and mortality in women in Australia. This study aimed to assess whether cervical cancer rates in migrant women in the state of New South Wales (NSW) showed a similar pattern of change to that in Australian-born women after 1991.
Data from the NSW Central Cancer Registry were obtained for females 15+ years diagnosed with invasive cervical cancer from 1973 to 2008 (N=11,485). We used joinpoint regression to assess annual percent changes (APC) in cervical cancer incidence and mortality before and after the introduction of organised cervical screening in 1991.
APC in incidence fell more rapidly after than before 1991 (p<0.001) amongst women from seven groups defined by country of birth (including Australia). There was only weak evidence that the magnitude of this incidence change varied by country-of-birth (p=0.088). The change in APC in mortality after 1991, however, was heterogeneous by country of birth (p=0.004). For Australian and UK or Ireland-born women the mortality APC fell more rapidly after 1991 than before (p=0.002 and p=0.001 respectively), as it did for New Zealand, Middle East, North Africa and Asian-born (p≥0.05), but in other European-born and women from the ’Rest of the World’ it appeared to rise (p=0.40 and p=0.013 respectively).
Like Australian-born women, most, but not all, groups of migrant women experienced an increased rate of fall in incidence of cervical cancer following introduction of organised cervical screening in 1991. An apparent rise in mortality in women in a ‘Rest of the World’ category might be explained by a recent rise in migration from countries with high cervical cancer incidence and mortality rates.
Genotyping has become more cost-effective and less invasive with the use of buccal cell sampling. However, low or fragmented DNA yields from buccal cells collected using FTA cards often requires additional whole genome amplification to produce sufficient DNA for genotyping. In our case–control study of childhood leukaemia, discordance was found between genotypes derived from blood and whole genome amplified FTA buccal DNA samples. We aimed to develop a user-friendly method to correct for this genotype misclassification, as existing methods were not suitable for use in our study.
Discordance between the results of blood and buccal-derived DNA was assessed in childhood leukaemia cases who had both blood and FTA buccal samples. A method based on applying misclassification probabilities to measured data and combining results using multiple imputations, was devised to correct for error in the genotypes of control subjects, for whom only buccal samples were available, to minimize bias in the odds ratios in the case–control analysis.
Application of the correction method to synthetic datasets showed it was effective in producing correct odds ratios from data with known misclassification. Moreover, when applied to each of six bi-allelic loci, correction altered the odds ratios in the logically anticipated manner given the degree and direction of the misclassification revealed by the investigations in cases. The precision of the effect estimates decreased with decreasing size of the misclassification data set.
Bias arising from differential genotype misclassification can be reduced by correcting results using this method whenever data on concordance of genotyping results with those from a different and probably better DNA source are available.
Biostatistics; DNA; Genotype; Measurement error; Quality control; Whole genome amplification
A model has been proposed whereby melanomas arise through two distinct pathways dependent upon the relative influence of host susceptibility and sun exposure. Such pathways may explain site-specific patterns of melanoma occurrence. To explore this model, we investigated the relationship between melanoma risk and general markers of acute (recalled sunburns) and chronic (prevalent solar keratoses) sun exposure, stratified by anatomic site and host phenotype. Our working hypothesis was that head and neck melanomas have stronger associations with solar keratoses and weaker associations with sunburn than trunk melanomas. We conducted a collaborative analysis using original data from women subjects of 11 case–control studies of melanoma (2575 cases, 3241 controls). We adjusted for potential confounding effects of sunlamp use and sunbathing. The magnitude of sunburn associations did not differ significantly by melanoma site, nevus count or histologic sub-type of melanoma. Across all sites, relative risk of melanoma increased with an increasing number of reported lifetime ‘painful’ sunburns, lifetime ‘severe’ sunburns and ‘severe’ sunburns in youth (ptrend<0.001), with pooled odds ratios for the highest category of sunburns vs no sunburns of 3.22 (95%CI 2.04–5.09) for lifetime ‘painful’ sunburns, 2.10 (95%CI 1.30–3.38) for lifetime ‘severe’ sunburns, and 2.43 (95%CI 1.61–3.65) for ‘severe’ sunburns in youth. Solar keratoses strongly increased the risk of head and neck melanoma (pOR 4.91, 95% CI 2.10–11.46), but data were insufficient to assess risk for other sites. Reported sunburn is strongly associated with melanoma on all major body sites.
Sunbed use is associated with increased risk of melanoma. Younger people might be more susceptible to the carcinogenic effects of ultraviolet radiation. We investigated the association between sunbed use and risk of early-onset cutaneous malignant melanoma. From the Australian Melanoma Family Study, a multi-centre, population-based, case-control-family study, we analysed data for 604 cases diagnosed between ages 18 and 39 years and 479 controls. Data were collected by interview. Associations were estimated as odds ratios (ORs) using unconditional logistic regression, adjusting for age, sex, city, education, family history, skin colour, usual skin response to sunlight, and sun exposure. Compared with having never used a sunbed, the OR for melanoma associated with ever-use was 1.41 (95% confidence interval (CI) 1.01-1.96), and 2.01 (95% CI 1.22-3.31) for more than 10 lifetime sessions (Ptrend 0.01 with cumulative use). The association was stronger for earlier age at first use (Ptrend 0.02). The association was also stronger for melanoma diagnosed when aged 18-29 years (OR for more than 10 lifetime sessions = 6.57, 95% CI 1.41-30.49) than for melanoma diagnosed when 30-39 years (OR 1.60, 95% CI 0.92-2.77; Pinteraction 0.01). Among those who had ever used a sunbed and were diagnosed between 18-29 years of age, three quarters (76%) of melanomas were attributable to sunbed use. Sunbed use is associated with increased risk of early-onset melanoma, with risk increasing with greater use, an earlier age at first use and for earlier onset disease.
sunbed; artificial tanning; melanoma; risk factor; early-onset
We report a genome-wide association study of melanoma, conducted by GenoMEL, of 2,981 cases, of European ancestry, and 1,982 study-specific controls, plus a further 6,426 French and UK population controls, all genotyped for 317,000 or 610,000 SNPs. The analysis confirmed previously known melanoma susceptibility loci. The 7 novel regions with at least one SNP with p<10−5 and further local imputed or genotyped support were selected for replication using two other genome-wide studies (from Australia and Houston, Texas). Additional replication came from UK and Dutch case-control series. Three of the 7 regions replicated at p<10−3: an ATM missense polymorphism (rs1801516, overall p=3.4×10−9); a polymorphism within MX2 (rs45430, p=2.9×10−9) and a SNP adjacent to CASP8 (rs13016963, p=8.6×10−10). A fourth region near CCND1 remains of potential interest, showing suggestive but inconclusive evidence of replication. Unlike the previously known regions, the novel loci showed no association with nevus or pigmentation phenotypes in a large UK case-control series.
To assess whether screening people at high risk of malignant melanoma would be effective in reducing the mortality from the disease data from 400 case-control pairs in a study of cutaneous malignant melanoma conducted in Western Australia during 1980-1 were used to predict the risk of melanoma in the remaining 111 pairs. All variables previously shown to be associated with a decrease or increase in the incidence of melanoma were considered for inclusion in a single conditional logistic regression model of the incidence of melanoma in the randomly chosen subset of 400 case-control pairs. Five of these variables—number of raised naevi on the arms, arrival in Australia before 10 years of age, history of non-melanocytic skin cancer, time spent outdoors in summer from the age of 10 to 24, and family history of melanoma—provided good discrimination between patients and controls in this sample and the 111 other case-control pairs. Among the 222 subjects in these other case-control pairs a group defined as being at high risk of melanoma by a risk score derived from these five variables contained 60 (54%) of the patients with melanoma but only 18 (16%) of the controls.
These data suggest that in Western Australia more than half of all new patients with melanoma arise in an identifiable subpopulation constituting less than one fifth of the whole population. Identifying this subpopulation and screening it regularly for cutaneous malignant melanoma could be cost effective in reducing mortality from this disease.
So far, two familial melanoma genes have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases1, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds2. To identify other familial melanoma genes, here we conducted whole-genome sequencing of probands from several melanoma families, identifying one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log odds ratio (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case–control sample. Likewise, it was similarly associated in an independent case–control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.
Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure although the associations of ultraviolet (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 (OR for top exposure quartile, 5.20; 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 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 the reason that people with more nevi may be less prone to solar elastosis.
solar elastosis; UV; sun exposure; pigmentation; nevi
Population-based patterns of care studies are important for monitoring cancer care but conducting them is expensive and resource-intensive. Linkage of routinely collected administrative health data may provide an efficient alternative. Our aim was to determine the accuracy of linked routinely collected administrative data for monitoring prostate cancer care in New South Wales (NSW), Australia.
The NSW Prostate Cancer Care and Outcomes Study (PCOS), a population-based survey of patterns of care for men aged less than 70 years diagnosed with prostate cancer in NSW, was linked to the NSW Cancer Registry, electronic hospital discharge records and Medicare and Pharmaceutical claims data from Medicare Australia. The main outcome measures were treatment with radical prostatectomy, any radiotherapy, external beam radiotherapy, brachytherapy or androgen deprivation therapy, and cancer staging. PCOS data were considered to represent the true treatment status. The sensitivity and specificity of the administrative data were estimated and relevant patient characteristics were compared using chi-squared tests.
The validation data set comprised 1857 PCOS patients with treatment information linked to Cancer Registry records. Hospital and Medicare claims data combined described treatment more accurately than either one alone. The combined data accurately recorded radical prostatectomy (96% sensitivity) and brachytherapy (93% sensitivity), but not androgen deprivation therapy (76% sensitivity). External beam radiotherapy was rarely captured (5% sensitivity), but this was improved by including Medicare claims for radiation field setting or dosimetry (86% sensitivity). False positive rates were near 0%. Disease stage comparisons were limited by one-third of cases having unknown stage in the Cancer Registry. Administrative data recorded treatment more accurately for cases in urban areas.
Cancer Registry and hospital inpatient data accurately captured radical prostatectomy and brachytherapy treatment, but not external beam radiotherapy or disease stage. Medicare claims data substantially improved the accuracy with which all major treatments were recorded. These administrative data combined are valid for population-based studies of some aspects of prostate cancer care.