European ancestry and polymorphisms in DNA repair genes modify the risk of melanoma: A case–control study in a high UV index region in Brazil

The risk of ultraviolet exposure for melanoma in Fitzpatrick skin types I-IV: A 20-year systematic review with meta-analysis for sunburns

Within the last two decades, no studies have comprehensively reviewed the risk of varying types of ultraviolet (UV) exposure on melanoma in fairer skinned individuals. Our research objective was to determine whether or not there was a change in the risk of UV exposure with development of melanoma in Fitzpatrick skin types I-IV based on more recent data over the past 20 years. We performed a systematic review from January 2002 to December 2021 analysing UV exposure and melanoma risk in Fitzpatrick type I-IV individuals. Out of 19,852 studies, 26 met inclusion criteria. Data spanned subjects from national and multinational cohorts (USA, Europe, Australia, Asia and South America). Twenty studies (77%, 20/26) identified a significant association between UV exposure and melanoma incidence. Sunburn was the most commonly assessed risk factor. Sunburn studies encompassed 3417 melanoma and found positive significant odds ratios (OR [95% CI]) in 11 out of 13 studies, ranging from 1.23 [1.01-1.49] to 8.48 [4.35-16.54]. Pooled analysis of the risk of melanoma with sunburn history found an unadjusted odds ratio of 1.66 [1.40-1.97] and adjusted odds ratio of 1.23 [1.04-1.46]. Cumulative sun exposure, measured as number of hours of sun exposure or calculated UV flux, was the second most common risk factor, encompassing 913 melanomas with positive significant ORs ranging from 1.1 [1.0-1.2] to 5.2 [2.1-12.5]. For other forms of UV exposure, a majority of studies showed an association with UV index (6/9), outdoor leisure activity (3/3) and left-sided laterality (1/1). Overall, UV exposure should continue to be considered a modifiable risk factor for melanoma in individuals of fairer skin.

Xeroderma Pigmentosum: A Genetic Condition Skin Cancer Correlated—A Systematic Review

Background. Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder of UV radiation-induced damage repair that is characterized by photosensitivity and a propensity for developing, among many others, skin cancers at an early age. This systematic review focused on the correlation between the clinical, pathological, and genetic aspects of XP and skin cancer. Methods. A systematic review was conducted through a literature search of online databases PubMed, Cochrane Library, SciELO, and Google Scholar. Search terms were “Xeroderma pigmentosum”, “XP”, “XPC”, “Nucleotide excision repair”, “NER”, “POLH”, “Dry pigmented skin”, and “UV sensitive syndrome” meshed with the terms “Skin cancer”, “Melanoma”, and “NMSC”. Results. After 504 abstracts screening, 13 full-text articles were assessed for eligibility, and 3 of them were excluded. Ten articles were selected for qualitative assessment. Conclusions. Patients with XP usually suffer shorter lives due to skin cancer and neurodegenerative disease. Deletion/alteration of a distinct gene allele can produce different types of cancer. The XPC and XP-E variants are more likely to have skin cancer than patients in other complement groups, and the most common cause of death for these patients is skin cancer (metastatic melanoma or invasive SCC). Still, aggressive preventative measures to minimize UV radiation exposure can retard the course of the disease and improve the quality of life.

Association of XPC Polymorphisms with Cutaneous Malignant Melanoma Risk: Evidence from a Meta-Analysis

BACKGROUND

A number of studies have reported that the xeroderma pigmentosum complementation group C (XPC) polymorphisms are associated with cutaneous malignant melanoma (CMM) susceptibility. But the results of those studies were inconsistent. Here, we performed a study to obtain a more conclusive result on the association of XPC polymorphisms with risk of CMM.

METHODS

The XPC Lys939Gln and Ala499Val polymorphisms were genotyped in 150 CMM cases and 150 controls by PCR-RFLP assay. Subsequently, all published relevant studies were identified through a comprehensive literature search in PubMed, Web of Science, and CNKI databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of correlation.

RESULTS

There was no significant association between XPC Lys939Gln and Ala499Val polymorphisms and CMM risk in our population. A total of 15 case-control studies including ten studies with 5,990 cases and 7,697 controls on XPC Lys939Gln and five studies with 3,139 cases and 3,721 controls on XPC Ala499Val polymorphism were selected. Pooled data revealed that XPC Lys939Gln (C vs. A: OR = 1.108, 95% CI 1.008- 1.217; P = 0.033) and Ala499Val (C vs. A: OR = 0.918, 95% CI 0.850-0.992; p = 0.031; CC+CA vs. AA: OR = 0.904, 95% CI 0.819-0.997; p = 0.043) polymorphisms were significantly associated with an increased risk of CMM. Moreover, stratified analyses by ethnicity revealed that the XPC Ala499Val and Lys939Gln polymorphisms were significantly associated with risk of CMM in Caucasians and mixed populations, respectively.

CONCLUSIONS

This meta-analysis result suggested that XPC Lys939Gln and Ala499Val polymorphisms were significantly associated with risk of CMM.

XPG rs17655 G>C polymorphism associated with cancer risk: evidence from 60 studies

Xeroderma pigmentosum group G (XPG), a key component in nucleotide excision repair pathway, functions to cut DNA lesions during DNA repair. Genetic variations that alter DNA repair gene expression or function may decrease DNA repair ability and impair genome integrity, thereby predisposing to cancer. The association between XPG rs17655 G>C polymorphism and cancer risk has been investigated extensively, but the results remain contradictory. To get a more accurate conclusion, we performed a comprehensive meta-analysis of 60 case-control studies, involving 27,098 cancer cases and 30,535 healthy controls. Crude odds ratios (ORs) and 95% confidence interval (CIs) were calculated to determine the association of interest. Pooled analysis indicated that the XPG rs17655 G>C polymorphism increased the risk of overall cancer (CC vs. GG: OR=1.10, 95% CI=1.00-1.20; CG vs. GG: OR=1.06, 95% CI=1.02-1.11; CG+CC vs. GG: OR=1.07, 95% CI=1.02-1.12; C vs. G: OR=1.05, 95% CI=1.01-1.09). Stratification analysis by cancer type further showed that this polymorphism was associated with increased risk of gastric cancer and colorectal cancer. This meta-analysis indicated that the XPG gene rs17655 G>C polymorphism was associated with increased overall cancer risk, especially the risk of gastric cancer and colorectal cancer. Further validation experiments are needed to strength our conclusion.

Predictive value of excision repair cross-complementing group 2 gene Lys751Gln and Asp312Asn polymorphisms in melanoma risk

Epidemiological studies have assessed the association between excision repair cross-complementing group 2 (ERCC2) Lys751Gln and Asp312Asn polymorphisms and melanoma risk with conflicting results. Relevant articles were searched from PubMed, Embase, and Web of Science with a time limit of 3 September 2016. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the association. We performed this meta-analysis with 12 studies including 6157 cases and 8873 controls for Lys751Gln and nine studies including 5037 cases and 7542 controls for Asp312Asn polymorphism. Overall, no significant associations were found under all the models for Lys751Gln polymorphism, and significant associations were found for Asp312Asn polymorphism for AA versus GG (OR=1.12, 95% CI=1.00-1.26) and for the recessive model (OR=1.11, 95% CI=1.00-1.24). In the stratification analyses by source of control: for Lys751Gln polymorphism, significant associations were found for CC versus AA (OR=1.19, 95% CI=1.04-1.36) and the recessive model (OR=1.15, 95% CI=1.02-1.30); for Asp312Asn polymorphism, significant associations were found for AA versus GG (OR=1.31, 95% CI=1.11-1.53) and the recessive model (OR=1.29, 95% CI=1.11-1.50). This meta-analysis suggested that both the Lys751Gln and Asp312Asn polymorphisms were risk factors for melanoma risk in population-based subgroup.

Quantitative assessment of the association between XRCC1 Arg399Gln and Arg194Trp polymorphisms and risk of cutaneous melanoma

Accumulating evidence has suggested that the XRCC1 Arg399Gln and Arg194Trp polymorphisms might be related to cutaneous melanoma susceptibility. However, epidemiologic findings have been inconsistent. We have assessed reported studies by meta-analysis to perform a more precise estimation of the association between the XRCC1 two polymorphisms (Arg399Gln, Arg194Trp) and risk of cutaneous melanoma. A total of seven eligible articles were selected for this meta-analysis, including 3454 cases and 3811 controls for the XRCC1 Arg399Gln polymorphism and 1256 cases and 1575 controls for the XRCC1 Arg194Trp polymorphism. Overall, no significant associations were found in all genetic models when the studies were pooled into the meta-analysis for the Arg399Gln and Arg194Trp polymorphisms. When stratified by source of control, significant associations were found for the Arg399Gln polymorphism in the population-based subgroup under AA versus GG [odds ratio (OR)=1.43, 95% confidence interval (CI)=1.08-1.88]; the dominant model AA/GA versus GG (OR=1.25, 95% CI=1.04-1.51); and the recessive model AA versus GA/GG (OR=1.31, 95% CI=1.01-1.68). No significant associations were found for the Arg194Trp polymorphism in the subgroup analysis. This meta-analysis suggested that the XRCC1 Arg399Gln polymorphism was a risk factor for cutaneous melanoma in population-based subgroup.

Quantitative assessment of the influence of X-ray repair cross-complementing group 3 rs861539 polymorphism and cutaneous melanoma susceptibility

Previous studies evaluating the association between X-ray repair cross-complementing group 3 (XRCC3) rs861539 polymorphism and cutaneous melanoma susceptibility reported conflicting findings. To draw a more precise association between XRCC3 rs861539 polymorphism and cutaneous melanoma susceptibility, we searched PubMed, EMBASE and Web of Science for case-control studies. A total of eight case-control studies including 3463 cases of melanoma and 4216 controls were included in the meta-analysis. Overall, no significant associations were found between XRCC3 rs861539 polymorphism and cutaneous melanoma susceptibility under all four genetic models (TT vs CC: OR 0.99, 95 % CI 0.86-1.14; TC vs CC: OR 0.92, 95 % CI 0.83-1.01; dominant model: OR 0.94, 95 % CI 0.85-1.03; recessive model: OR 1.05, 95 % CI 0.92-1.19). In the subgroup by source of control, no significant associations were found in hospital-based and population-based subgroup. This meta-analysis suggested that the XRCC3 rs861539 polymorphism was not a risk factor for cutaneous melanoma susceptibility.

A meta-analysis of XPC Lys939Gln polymorphism and melanoma susceptibility

BACKGROUND

It has been reported that polymorphisms of XPC Lys939Gln may affect the risk of melanom. However, the results have been inconsistent.We performed a comprehensive meta-analysis to determine the association between XPC Lys939Gln polymorphism and melanoma susceptibility.

METHODS

Based on comprehensive searches of the MEDLINE, EMBASE and ISI Web of knowledge, China National Knowledge Infrastructure (CNKI) and Wanfang Database, we identified eligible studies about the association between XPC Lys939Gln polymorphism and melanoma risk.

RESULTS

A total of 4631 cases and 5111 controls in studies were included in this meta-analysis. All studies were conducted in Caucasian populations. Allele model (Gln vs. Lys: P = 0.22; OR = 1.07, 95% CI = 0.96-1.18), and homozygous model (Gln/Gln vs. Lys/Lys: P = 0.66; OR = 1.03, 95% CI = 0.91-1.17) did not show increased risk of developing melanoma. Similarly, dominant model Gln/Gln and Gln/Lys vs. Lys/Lys: P = 0.07; OR = 1.17, 95% CI = 0.99-1.40) and recessive model (Gln/Gln vs. Gln/Lys and Lys/Lys: P = 0.67; OR = 1.03, 95% CI = 0.90-1.19) failed to show increased risk of developing melanoma.

CONCLUSION

Our pooled data suggest that there was no evidence for a major role of XPC Lys939Gln polymorphism in the pathogenesis of melanoma.

Epidemiology of melanoma in the South of Brazil: study of a city in the Vale do Itajaí from 1999 to 2013

BACKGROUND

Cutaneous melanoma is a highly aggressive malignancy with increasing incidence worldwide. The southern Brazilian state of Santa Catarina has one of the highest incidence rates of melanoma in the country.

OBJECTIVE

To evaluate the epidemiological profile of melanoma patients in a southern city of Brazil.

METHODS

a cross-sectional retrospective study was conducted, aiming to detect the clinical and histopathological characteristics of cutaneous melanoma diagnosed in the city of Brusque - SC, between 1999 and 2013.

RESULTS

A total of 213 cases in 212 individuals were studied. More than 50% of the patients were females (p< 0.05). The trunk was the most commonly affected site (p< 0.05), followed by the upper limbs. Nodular and superficial spreading melanomas were the most commonly detected in histological analyses. They did not differ statistically in frequency, but were more prevalent than other histopathological subtypes (p< 0.05). There was no statistically significant difference between invasive and noninvasive melanomas (p= 0.2441). Among the invasive melanomas, those with Breslow thicknesses < 1 mm and between 1-2mm were more prevalent (p< 0.05).

CONCLUSIONS

In this study we found a higher frequency of melanomas in female patients and patients aged over 51. The trunk was the most commonly affected site. Nodular and superficial spreading melanomas prevailed. Among invasive melanomas, those with Breslow thicknesses < 2 mm were the most frequent. This paper highlights the epidemiological profile of melanoma patients in the city and may help to identify and aid in the follow-up of those who are most likely to present the disease.

XRCC3 T241M polymorphism and melanoma skin cancer risk: A meta-analysis

Although the T241M polymorphism in the X-ray cross-complementing group 3 (XRCC3) gene has been implicated in the pathogenesis of melanoma, the results have been inconsistent. In this study, a meta-analysis was performed to assess the association of XRCC3 T241M polymorphism with melanoma. Published literature from PubMed and Embase databases was retrieved. The pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects models. A total of six case-control studies containing 2,133 patients and 3,141 controls were enrolled into this meta-analysis. In a combined analysis, the results revealed no significant association between XRCC3 T241M polymorphism and melanoma risk in the overall population. In the subgroup analysis by ethnicity, no significant associations between the XRCC3 T241M polymorphism and melanoma risk were identified in Caucasians. However, when the analyses were restricted to three larger studies (n>500 cases), a significant association was noted with melanoma (TT vs. MT: OR=1.20, 95% CI=1.04-1.38; dominant model: OR=0.86, 95% CI=0.75-0.98). In conclusion, the meta-analysis results suggest that the XRCC3 T241M polymorphism was associated with risk of melanoma. Further large and well-designed studies are needed to confirm this conclusion.

Determinação de um ponto de corte para a identificação de pares verdadeiros pelo método probabilístico de linkage de base de dados

O objetivo deste estudo foi propor pontos de corte nos escores calculados no processo de linkage probabilístico, para as diversas topografias de câncer. Neste estudo foi utilizada a base de dados do RCBP-SP, composta por 343.306 casos incidentes de câncer do município de São Paulo, registrados no período de 1997 a 2005, com idades que variaram de menos um a 106 anos, de ambos os sexos. Para o linkage probabilístico, realizado no programa Reclink III, foram utilizadas a base de dados do PRO-AIM e APAC-SIA/SUS. Foram calculados os valores da área sob a curva, sensibilidade e especificidade para determinar o ponto de corte do escore de maior precisão na identificação dos pares verdadeiros. Na análise das topografias, verificou-se que o ponto de corte no escore 18 apresentou boa acurácia, com valores de sensibilidade que variaram de 73,7 a 96,7% e de especificidade de 98,5 a 99,4%. Conclui-se que, acima do escore 18 encontravam-se quase a totalidade dos pares verdadeiros, enquanto que abaixo deste, menos de 1% dos registros vinculados eram verdadeiros.

Association between the XRCC1 Arg194Trp polymorphism and risk of cancer: evidence from 201 case-control studies

The Arg194Trp polymorphism in the X-ray cross-complementing group 1 (XRCC1) had been implicated in cancer susceptibility. The previous published data on the association between XRCC1 Arg194Trp polymorphism and cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between cancer susceptibility and XRCC1 Arg194Trp (59,227 cases and 81,587 controls from 201 studies) polymorphism in different inheritance models. We used odds ratios with 95 % confidence intervals to assess the strength of the association. Overall, significantly increased cancer risk was found (recessive model: (odds ration [OR] = 1.18, 95% confidence interval [CI] = 1.09-1.27; homozygous model: OR = 1.21, 95% CI = 1.10-1.33; additive model: OR = 1.05, 95% CI = 1.01-1.09) when all eligible studies were pooled into the meta-analysis. In further stratified and sensitivity analyses, significantly increased glioma risk was found among Asians, significantly decreased lung cancer risk was found among Caucasians, and significant increased breast cancer risk was found among hospital-based studies. In summary, this meta-analysis suggests that Arg194Trp polymorphism may be associated with increased breast cancer risk, Arg194Trp polymorphism is associated with increased glioma risk among Asians, and Arg194Trp polymorphism is associated with decreased lung cancer risk among Caucasians. In addition, our work also points out the importance of new studies for Arg194Trp association in some cancer types, such as gastric, pancreatic, prostate, and nasopharyngeal cancers, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the XRCC1 Arg194Trp polymorphism in cancer development (I (2) > 75%).

Current evidences on the XPG Asp1104His polymorphism and melanoma susceptibility: a meta-analysis based on case-control studies

Previous studies evaluating the association between the XPG Asp1104His polymorphism and melanoma susceptibility remained controversial. To draw a more precise estimation of the relationship, a total of eight published case-control studies containing 5,212 cases and 7,045 controls were included for meta-analysis. Overall, a significant association was found between the XPG Asp1104His polymorphism and melanoma susceptibility for the dominant model (OR = 2.42, 95 % CI = 2.26-2.60). In subgroup analysis by source of control, there was an obvious association was found among Population-based subgroup for the dominant model CC+GC vs GG (OR 2.51, 95 % CI 2.28-2.77), among the Hospital-based subgroup, an obvious association was also found for the dominant model CC+GC vs GG (OR 2.34, 95 % CI 2.12-2.58). This meta-analysis suggested that the XPG Asp1104His polymorphism was a risk factor for melanoma susceptibility.

Association between the XPG Asp1104His and XPF Arg415Gln polymorphisms and risk of cancer: a meta-analysis

BACKGROUND

The XPG (xeroderma pigmentosum type G) Asp1104His and XPF (xeroderma pigmentosum type F) Arg415Gln polymorphisms had been implicated in cancer susceptibility. The previous published data on the association between XPG Asp1104His and XPF Arg415Gln polymorphisms and cancer risk remained controversial.

METHODOLOGY/PRINCIPAL FINDINGS

To derive a more precise estimation of the association between the XPG Asp1104His and XPF Arg415Gln polymorphisms and overall cancer risk, we performed a meta-analysis to investigate the association between cancer susceptibility and XPG Asp1104His (32,162 cases and 39,858 controls from 66 studies) and XPF Arg415Gln polymorphisms (17,864 cases and 20,578 controls from 32 studies) in different inheritance models. We used odds ratios with 95% confidence intervals to assess the strength of the association. Overall, significantly elevated cancer risk was found when all studies were pooled into the meta-analysis of XPG Asp1104His (dominant model: OR = 1.05, 95% CI = 1.00-1.10; Asp/His vs. Asp/Asp: OR = 1.06, 95% CI = 1.01-1.11). In the further stratified and sensitivity analyses, significantly decreased lung cancer risk was found for XPF Arg415Gln (dominant model: OR = 0.82, 95% CI = 0.71-0.96; Arg/Gln versus Arg/Arg: OR = 0.83, 95% CI = 0.71-0.97; additive model: OR = 0.83, 95% CI = 0.72-0.95) and significantly increased other cancer risk was found among hospital-based studies for XPG Asp1104His (dominant model: OR = 1.23, 95% CI = 1.02-1.49).

CONCLUSIONS/SIGNIFICANCE

In summary, this meta-analysis suggests that XPF Arg415Gln polymorphism may be associated with decreased lung cancer risk and XPG Asp1104His may be a low-penetrant risk factor in some cancers development. And larger scale primary studies are required to further evaluate the interaction of XPG Asp1104His and XPF Arg415Gln polymorphisms and cancer risk in specific populations.

Quantitative assessment of the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk

Previous studies evaluating the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk reported conflicting findings. We searched PubMed and Embase databases up to May 16, 2013 to identify eligible studies on the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk. Finally, a total of seven case-control studies including 3,971 cases of cutaneous melanoma and 5,873 controls were included in the meta-analysis. Statistical analysis was performed with STATA version 11.0. Odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were used to assess the strength of the association. Overall, there was no association between XPC Lys939Gln polymorphism and cutaneous melanoma risk under all five genetic models (Gln vs. Lys: OR = 1.11, 95 % CI = 0.98-1.26, P = 0.10; GlnGln vs. LysLys: OR = 1.26, 95 % CI = 0.98-1.61, P = 0.07; LysGln vs. LysLys: OR = 1.04, 95 % CI = 0.88-1.22, P = 0.64; GlnGln/LysGln vs. LysLys: OR = 1.10, 95 % CI = 0.92-1.31, P = 0.29; GlnGln vs. LysLys/LysGln: OR = 1.19, 95 % CI = 0.99-1.43, P = 0.06). Subgroup analysis in Caucasians showed that there was an obvious association between XPC Lys939Gln polymorphism and cutaneous melanoma risk in Caucasians (GlnGln vs. LysLys/LysGln: OR = 1.12, 95 % CI = 1.00-1.25, P = 0.05). Sensitivity analysis by omitting one study in turns showed that the significance of the pooled ORs was not stable. In addition, there was some evidence of publication bias in the meta-analysis, and meta-analyses of the studies with large sample size did not find the obvious association between XPC Lys939Gln polymorphism and cutaneous melanoma risk in Caucasians. Therefore, there is little evidence for the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk.

XRCC3 C18067T polymorphism contributes a decreased risk to both basal cell carcinoma and squamous cell carcinoma: evidence from a meta-analysis

Background

The X-ray repair cross-complementing group 3 (XRCC3) in homologous recombination repair (HRR) pathway plays a very important role in DNA double-strand break repair (DSBR). Variations in the XRCC3 gene might lead to altered protein structure or function which may change DSBR efficiency and result in cancer. The XRCC3 C18067T polymorphism has been reported to be associated with skin cancer susceptibility, yet the results of these previous results have been inconsistent or controversial. To derive a more precise estimation of the association, we conducted a meta-analysis.

Methods

The quality of the studies was assessed according to a predefined scale. The association between the XRCC3 C18067T polymorphism and skin cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

Results

Overall, no significant association was observed between XRCC3 C18067T polymorphism and skin cancer risk in any genetic model. Stratified analyses according to tumor type, significant association was found in the relationship between XRCC3 C18067T polymorphism and nonmelanoma skin cancer risk (homozygote comparison TT versus CC: OR = 0.74, 95%CI = 0.61–0.90, P = 0.003; recessive model TT versus TC/CC: OR = 0.81, 95%CI = 0.68–0.95, P = 0.01). Furthermore, significant association was also observed in XRCC3 C18067T polymorphism with both basal cell carcinoma risk (homozygote comparison TT versus CC: OR = 0.70, 95%CI = 0.53–0.92, P = 0.011; recessive model TT versus. TC/CC: OR = 0.74, 95%CI = 0.60–0.92, P = 0.007) and squamous cell carcinoma risk (heterozygote comparison TT versus .CC: OR = 0.81, 95%CI = 0.67–0.99, P = 0.04; dominant model TT/TC versus .CC: OR = 0.81, 95%CI = 0.68–0.98, P = 0.029).

Conclusion

The present meta-analysis demonstrates that XRCC3 C18067T polymorphism was not associated with risk of cutaneous melanoma but contributed a decreased risk to both basal cell carcinoma and squamous cell carcinoma.

Association between genetic polymorphisms in apoptosis-related genes and risk of cutaneous melanoma in women and men

BACKGROUND

The P53 Arg72Pro, MDM2 c.+309T>G, BAX c.-248G>A, and BCL2 c.-717C>A polymorphisms have variable roles in the apoptosis pathways.

OBJECTIVE

To clarify the roles of these polymorphisms in the risk for cutaneous melanoma (CM).

METHODS

Genomic DNA of 200 CM patients and 215 controls was analyzed by PCR-RFLP.

RESULTS

In women, the frequencies of BAX GG (83.0% vs. 71.0%, P=0.04), BCL2 AA (32.0% vs. 15.0%, P=0.003), P53 ArgArg plus BAX GG (84.9% vs. 63.2%, P=0.01), P53 ArgArg plus BCL2 AA (37.0% vs. 13.1%, P=0.003), BAX GG plus BCL2 AA (70.3% vs. 33.3%, P=0.001), MDM2 GG plus BAX GG plus BCL2 AA (27.3% vs. 3.7%, P=0.03), and P53 ArgArg plus MDM2 GG plus BAX GG plus BCL2 AA (33.3% vs. 5.6%, P=0.04) genotypes were higher in patients than in controls. Female carriers of the respective genotypes were under 1.98 (95% CI: 1.01-3.91), 2.87 (95% CI: 1.43-5.77), 3.48 (95% CI: 1.34-9.04), 4.23 (95% CI: 1.63-10.96), 6.04 (95% CI: 2.10-17.37), 25.61 (95% CI: 1.29-507.24), and 25.69 (95% CI: 1.11-593.59)-fold increased risks for CM than others, respectively. In men, the frequencies of BCL2 CA+AA (83.0% vs. 67.6%, P=0.01) and MDM2 TG+GG plus BCL2 CA+AA (94.2% vs. 68.3%, P=0.003) genotypes were higher in patients than in controls. Male carriers of the respective genotypes were under 2.43 (95% CI: 1.23-4.82) and 9.22 (95% CI: 2.16-39.31)-fold increased CM risks than others, respectively.

CONCLUSION

The data suggest for the first time that P53 Arg72Pro, MDM2 c.+309T>G, BAX c.-248G>A, and BCL2 c.-717C>A polymorphisms, enrolled in apoptosis pathways, constitute distinct determinants of CM in women and men.

Associations of Lys939Gln and Ala499Val polymorphisms of the XPC gene with cancer susceptibility: a meta-analysis

XPC polymorphisms may alter DNA repair capacity, thus leading to genetic instability and carcinogenesis. Numerous studies have investigated the associations of XPC Lys939Gln (rs2228001) and Ala499Val (rs2228000) polymorphisms with cancer susceptibility; however, the findings are inconclusive. We searched literature from MEDLINE and EMBASE for eligible publications that assessed the associations between these two polymorphisms and cancer risk. We also assessed genotype-mRNA expression correlation data from HapMap for rs2228001 and rs2228000 in normal cell lines derived from 270 subjects with different ethnicities. The final analysis included 62 published studies of 25,708 cases and 30,432 controls for the Lys939Gln and 34 studies with 14,877 cases and 17,888 controls for the Ala499Val. Overall, Lys939Gln was significantly associated with an increased overall cancer risk (Gln/Gln vs. Lys/Lys: OR = 1.16, 95% CI = 1.07 - 1.25, p < 0.001; recessive model: OR = 1.14, 95% CI = 1.06 - 1.22, p < 0.001; dominant model: OR = 1.06, 95% CI = 1.01 - 1.11, p = 0.015 and Gln vs. Lys: OR = 1.07, 95% CI = 1.03 - 1.10, p < 0.001) and further stratifications showed an increased risk for bladder, lung and colorectal cancer, Asian populations and population-based studies. Likewise, Ala499Val was also significantly associated with an increased overall cancer risk (Val/Val vs. Ala/Ala: OR = 1.21, 95% CI = 1.07 - 1.36, p = 0.003 and recessive model: OR = 1.20, 95% CI = 1.08 - 1.34, p = 0.001) and further stratification showed an increased risk for breast and bladder cancer, particularly in Asian populations. Interestingly, significantly correlation between XPC genotypes and mRNA expression was found only for Asian populations as well. Despite some limitations, this meta-analysis established some solid statistical evidence for an association between XPC polymorphisms and cancer risk, which warrants further validation in single large studies.

Poly (AT) deletion/insertion polymorphism of the XPC gene contributes to urinary system cancer susceptibility: a meta-analysis

Numerous studies have investigated the association between xeroderma pigmentosum complementation group C (XPC) poly (AT) deletion/insertion (PAT -/+) polymorphism and cancer susceptibility; however, the findings are inconsistent. Therefore, we performed a meta-analysis based on 32 publications including 10,214 cases and 11,302 controls to acquire a more robust estimation of the relationship. We searched publications from MEDLINE, EMBASE and CBM which assessed the associations between XPC PAT -/+ polymorphism and cancer risk. We calculated pooled odds ratio (OR) and 95% confidence interval (CI) by using either fixed-effects or random-effects model. We found that individuals carrying the PAT +/+ genotype have significantly increased cancer risk (PAT +/+ vs.

PAT -/-

OR=1.18, 95% CI=1.03-1.35 and recessive model: OR=1.19, 95% CI=1.06-1.33). Further stratification analysis showed a significantly increased risk for prostate cancer (PAT +/+ vs.

PAT -/-

OR=2.20, 95% CI=1.39-3.48, recessive model: OR=2.07, 95% CI=1.33-3.23 and PAT + vs.

PAT -

OR=1.39, 95% CI=1.12-1.71), bladder cancer (recessive model: OR=1.33, 95% CI=1.03-1.72), Caucasian ethnicity (recessive model: OR=1.21, 95% CI=1.02-1.43), population-based studies (recessive model: OR=1.23, 95% CI=1.05-1.43) and studies with relatively large sample size (PAT +/+ vs.

PAT -/-

OR=1.18, 95% CI=1.04-1.35 and recessive model: OR=1.20, 95% CI=1.08-1.33). Despite some limitations, this meta-analysis established solid statistical evidence for the association between the XPC PAT +/+ genotype and cancer risk, especially for urinary system cancer, but this association warrants further validation in single large studies.

Assessment of the XPC (A2920C), XPF (T30028C), TP53 (Arg72Pro) and GSTP1 (Ile105Val) polymorphisms in the risk of cutaneous melanoma

PURPOSE

We examined the influence of XPC A2920C, XPF T30028C, TP53 Arg72Pro and GSTP1 Ile105Val polymorphisms in the risk of cutaneous melanoma (CM).

METHODS

DNA from 146 CM patients and 146 controls was analysed by polymerase chain reaction (PCR)--restriction fragment length polymorphism (RFLP).

RESULTS

The frequencies of XPC CC (15.1 vs. 6.9 %, P = 0.02), TP53 ArgArg (59.6 vs. 45.9 %, P = 0.02), XPC CC plus TP53 ArgArg (19.7 vs. 5.2 %, P = 0.01) and TP53 ArgArg plus GSTP1 IleIle (50.7 vs. 35.6 %, P = 0.03) genotypes were higher in patients than in controls. Carriers of the respective genotypes were under a 2.51 (95 % CI: 1.13-5.55), 1.76 (95 % CI: 1.09-2.83), 4.52 (95 % CI: 1.35-15.16), and 2.01 (95 % CI: 1.04-3.90)-fold increased risks for CM than others, respectively. An excess of TP53 ArgArg genotype was seen in patients with excessive sun exposure compared to patients with standard sun exposure (69.2 vs. 44.1 %, P = 0.02) and also compared to controls (69.2 vs. 45.9 %, P = 0.002). Individuals with TP53 ArgArg genotype and highly exposed to sunlight had 2.65 (95 % CI: 1.42-4.92)-fold increased risk for CM than others. XPC CC (27.8 vs. 10.4 %, P = 0.02) and the GSTP1 IleIle (58.3 vs. 36.8 %, P = 0.04) genotypes were more common in patients with advanced tumours than in patients with localized tumours and were also more common in these patients than in controls (27.8 vs. 6.9 %, P = 0.001; 58.3 vs. 37.0 %, P = 0.02, respectively). Individuals with the respective genotypes had 5.23 (95 % CI: 1.97-13.82)-fold and 2.38 (95 % CI: 1.13-5.01)-fold increased risks for advanced tumour than others, respectively.

CONCLUSION

Our data suggest that inherited abnormalities of XPC, XPF, TP53 and GSTP1 pathways of the DNA repair, apoptosis and metabolism of reactive oxygen species are important determinants of CM in individuals from south-eastern Brazil.

Association between the XRCC3 T241M polymorphism and risk of cancer: evidence from 157 case-control studies

The T241M polymorphism in the X-ray cross-complementing group 3 (XRCC3) had been implicated in cancer susceptibility. The previous published data on the association between XRCC3 T241M polymorphism and cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between cancer susceptibility and XRCC3 T241M (61,861 cases and 84,584 controls from 157 studies) polymorphism in different inheritance models. We used odds ratios with 95% confidence intervals to assess the strength of the association. Overall, significantly increased cancer risk was observed in any genetic model (dominant model: odds ration [OR]=1.07, 95% confidence interval [CI]=1.00-1.13; recessive model: OR=1.15, 95% CI=1.08-1.23; additive model: OR=1.17, 95% CI=1.08-1.28) when all eligible studies were pooled into the meta-analysis. In further stratified and sensitivity analyses, the elevated risk remained for subgroups of bladder cancer and breast cancer, especially in Caucasians. In addition, significantly decreased lung cancer risk was also observed. In summary, this meta-analysis suggests the participation of XRCC3 T241M in the susceptibility for bladder cancer and breast cancer, especially in Caucasians, and XRCC3 T241M polymorphism is associated with decreased lung cancer risk. Moreover, our work also points out the importance of new studies for T241M association in some cancer types, such as gastric cancer, colorectal cancer, and melanoma skin cancer, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the XRCC3 polymorphism in cancer development.

Xeroderma pigmentosum genes and melanoma risk

Xeroderma pigmentosum is a rare autosomal recessive disease that is associated with a severe deficiency in nucleotide excision repair. The presence of a distinct the nucleotide excision repair (NER) mutation signature in melanoma suggests that perturbations in this critical repair process are likely to be involved with disease risk. We hypothesized that persons with polymorphic NER gene(s) are likely to have reduced NER activity and are consequently at an increased risk of melanoma development. We assessed the association between 94 SNPs within seven XP genes (XPA-XPG) and the melanoma risk in the Polish population. We genotyped 714 unselected melanoma patients and 1,841 healthy adults to determine if there were any polymorphisms differentially represented in the disease group. We found that a significantly decreased risk of melanoma was associated with the Xeroderma pigmentosum complementation (XPC) rs2228000_CT genotype (odds ratio [OR] = 0.15; p < 0.001) and the rs2228000_TT genotype (OR = 0.11; p < 0.001) compared to the reference genotype. Haplotype analysis within XPC revealed the rs2228001_A + G1475A_G + G2061A_A + rs2228000_T + rs3731062_C haplotype (OR = 0.26; p < 0.05) was associated with a significantly decreased disease risk. The haplotype analysis within the Xeroderma pigmentosum group D (XPD) showed a modest association between two haplotypes and a decrease in melanoma risk. There were no major differences between the prevalence of the XP polymorphisms among young or older patients with melanoma. Linkage disequilibrium of XPC: rs2228001, G1475A, G2061A, rs2228000 and rs3731062 was found. The data from our study support the notion that only XPC and XPD genes are associated with melanoma susceptibility.

Association between the ERCC5 Asp1104His polymorphism and cancer risk: a meta-analysis

BACKGROUND

Excision repair cross complementing group 5 (ERCC5 or XPG) plays an important role in regulating DNA excision repair, removal of bulky lesions caused by environmental chemicals or UV light. Mutations in this gene cause a rare autosomal recessive syndrome, and its functional single nucleotide polymorphisms (SNPs) may alter DNA repair capacity phenotype and cancer risk. However, a series of epidemiological studies on the association between the ERCC5 Asp1104His polymorphism (rs17655, G>C) and cancer susceptibility generated conflicting results.

METHODOLOGY/PRINCIPAL FINDINGS

To derive a more precise estimation of the association between the ERCC5 Asp1104His polymorphism and overall cancer risk, we performed a meta-analysis of 44 published case-control studies, in which a total of 23,490 cases and 27,168 controls were included. To provide additional biological plausibility, we also assessed the genotype-gene expression correlation from the HapMap phase II release 23 data with 270 individuals from 4 ethnic populations. When all studies were pooled, we found no statistical evidence for a significantly increased cancer risk in the recessive genetic models (His/His vs. Asp/Asp: OR = 0.99, 95% CI: 0.92-1.06, P = 0.242 for heterogeneity or His/His vs. Asp/His + Asp/Asp: OR = 0.98, 95% CI: 0.93-1.03, P = 0.260 for heterogeneity), nor in further stratified analyses by cancer type, ethnicity, source of controls and sample size. In the genotype-phenotype correlation analysis from 270 individuals, we consistently found no significant correlation of the Asp1104His polymorphism with ERCC5 mRNA expression.

CONCLUSIONS/SIGNIFICANCE

This meta-analysis suggests that it is unlikely that the ERCC5 Asp1104His polymorphism may contribute to individual susceptibility to cancer risk.

Ethnicity and cutaneous melanoma in the city of Sao Paulo, Brazil: a case-control study

BACKGROUND

Over the last century the incidence of cutaneous melanoma has increased worldwide, a trend that has also been observed in Brazil. The identified risk factors for melanoma include the pattern of sun exposure, family history, and certain phenotypic features. In addition, the incidence of melanoma might be influenced by ethnicity. Like many countries, Brazil has high immigration rates and consequently a heterogeneous population. However, Brazil is unique among such countries in that the ethnic heterogeneity of its population is primarily attributable to admixture. This study aimed to evaluate the contribution of European ethnicity to the risk of cutaneous melanoma in Brazil.

METHODOLOGY/PRINCIPAL FINDINGS

We carried out a hospital-based case-control study in the metropolitan area of Sao Paulo, Brazil. We evaluated 424 hospitalized patients (202 melanoma patients and 222 control patients) regarding phenotypic features, sun exposure, and number of grandparents born in Europe. Through multivariate logistic regression analysis, we found the following variables to be independently associated with melanoma: grandparents born in Europe-Spain (OR = 3.01, 95% CI: 1.03-8.77), Italy (OR = 3.47, 95% CI: 1.41-8.57), a Germanic/Slavic country (OR = 3.06, 95% CI: 1.05-8.93), or ≥ 2 European countries (OR = 2.82, 95% CI: 1.06-7.47); eye color-light brown (OR = 1.99, 95% CI: 1.14-3.84) and green/blue (OR = 4.62; 95% CI 2.22-9.58); pigmented lesion removal (OR = 3.78; 95% CI: 2.21-6.49); no lifetime sunscreen use (OR = 3.08; 95% CI: 1.03-9.22); and lifetime severe sunburn (OR = 1.81; 95% CI: 1.03-3.19).

CONCLUSIONS

Our results indicate that European ancestry is a risk factor for cutaneous melanoma. Such risk appears to be related not only to skin type, eye color, and tanning capacity but also to others specific characteristics of European populations introduced in the New World by European immigrants.

Exonuclease 1 (EXO1) gene variation and melanoma risk

OBJECTIVE

DNA repair pathway genes play an important role in maintaining genomic integrity and protecting against cancer development. This study aimed to identify novel SNPs in the DNA repair-related genes associated with melanoma risk from a genome-wide association study (GWAS).

METHODS

A total of 8422 SNPs from the 165 DNA repair-related genes were extracted from a GWAS of melanoma risk, including 494 cases and 5628 controls from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). We further replicated the top SNPs in a GWAS of melanoma risk from the MD Anderson Cancer Center (1804 cases and 1026 controls).

RESULTS

A total of 3 SNPs with P value <0.001 were selected for in silico replication. One SNP was replicated: rs3902093 [A] in EXO1 promoter region (P(discovery)=6.6 × 10⁻⁴, P(replication)=0.039, P(joint)=2.5 × 10⁻⁴; OR(joint)=0.80, 95% CI: 0.71, 0.90). This SNP was associated with the expression of the EXO1; carriers of the A allele showed lower expression (P=0.002).

CONCLUSION

Our study found that a promoter region SNP in the editing and processing nucleases gene EXO1 was associated with decreased expression of EXO1 and decreased melanoma risk. Further studies are warranted to validate this association and to investigate the potential mechanisms.