A first-in-human phase 1 study of nofazinlimab, an anti-PD-1 antibody, in advanced solid tumors and in combination with regorafenib in metastatic colorectal cancer.

BACKGROUND: We assessed nofazinlimab, an anti-PD-1 antibody, in solid tumors and combined with regorafenib in metastatic colorectal cancer (mCRC). METHODS: This phase 1 study comprised nofazinlimab dose escalation (phase 1a) and expansion (phase 1b), and regorafenib dose escalation (80 or 120 mg QD, days 1-21 of 28-day cycles) combined with 300-mg nofazinlimab Q4W (part 2a) to determine safety, efficacy, and RP2D. RESULTS: In phase 1a (N = 21), no dose-limiting toxicity occurred from 1 to 10 mg/kg Q3W, with 200 mg Q3W determined as the monotherapy RP2D. In phase 1b (N = 87), 400-mg Q6W and 200-mg Q3W regimens were found comparable. In part 2a (N = 14), both regimens were deemed plausible RP2Ds. Fatigue was the most frequent treatment-emergent adverse event (AE) in this study. Any-grade and grade 3/4 nofazinlimab-related AEs were 71.4% and 14.3%, 56.3% and 5.7%, and 57.1% and 21.4% in phases 1a, 1b, and part 2a, respectively. ORRs were 14.3% and 25.3% in phases 1a and 1b, respectively. In part 2a, no patients had radiological responses. CONCLUSIONS: Nofazinlimab monotherapy was well tolerated and demonstrated preliminary anti-tumor activity in multiple tumor types. Regorafenib plus nofazinlimab had a manageable safety profile but was not associated with any response in mCRC. CLINICAL TRIAL REGISTR ATION: Clinicaltrials.gov (NCT03475251).

Serum HBcrAg and Hepatocellular Carcinoma in a Taiwanese Population Seronegative for HBsAg and Anti-HCV.

BACKGROUND & AIMS: Hepatitis B core-related antigen (HBcrAg) is a surrogate seromarker of intrahepatic hepatitis B virus covalently closed circular DNA quantity and activity and a predictor of hepatocellular carcinoma (HCC) in chronic hepatitis B patients. We assess association between HBcrAg and HCC in individuals seronegative for hepatitis B surface antigen and anti-hepatitis C virus (NBNC) in Taiwan. METHODS: A total of 129 newly developed HCC cases and 520 frequency-matched non-HCC controls were drawn from the REVEAL-NBNC cohort. Serum HBcrAg and other risk factors measured at recruitment were compared between cases and controls. Regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The proportion of baseline HBcrAg positivity (≥1000 U/mL) was significantly higher in HCC cases than in controls (12.4% vs 1.4%, P < .001). In multivariate analysis, HBcrAg positivity was associated with significantly higher risk of HCC (adjusted OR [95% CI]: 9.3 [3.3-26.4]; P < .001]. The HCC population attributable to HBcrAg positivity was 11.1% (95% CI: 9.7%-12.5%). CONCLUSIONS: Seropositivity of HBcrAg might identify a subset of the NBNC population at higher risk of HCC in hepatitis B virus endemic areas.

Serum soluble programmed death-1 levels predict the spontaneous HBeAg seroclearance in chronic hepatitis B.

BACKGROUND AND AIMS: In chronic hepatitis B virus (HBV) infection, earlier seroclearance of hepatitis B e antigen (HBeAg) is associated with more favorable outcomes. Soluble programmed cell death 1 (sPD-1) has been implicated in higher viral load and hepatocellular carcinoma. We investigated the association between sPD-1 levels and spontaneous HBeAg seroclearance. METHODS: Baseline serum samples from 488 HBeAg-seropositive patients in the REVEAL-HBV cohort were tested for sPD-1 levels. Among them, 329 with available follow-up serum samples were further assayed. Multivariate Cox regression analysis was used to estimate the adjusted rate ratio (aRR) and 95% confidence interval (CI) with adjustment of host and viral factors. The 66th percentile and an annual reduction of ≥ 10% were used as the cut-off point for baseline sPD-1 levels (high/low) and sPD-1 trajectory (decline/no decline), respectively. RESULTS: Lower baseline sPD-1 levels [aRR (95% CI): 2.19 (1.47-3.27)] and long-term decline in sPD-1 levels [aRR (95% CI): 4.08 (2.79-5.97)] were both independent predictors for HBeAg seroclearance. However, further stratification analysis by HBV genotype showed that lower baseline sPD-1 levels were significantly associated with HBeAg seroclearance only in genotype C infection [aRR (95% CI): 4.47 (2.38-8.37)] but not in genotype B infection. On the other hand, long-term decline in sPD-1 levels was predictive for HBeAg seroclearance regardless of HBV genotype with aRR (95% CI) of 4.62 (2.71-7.88) and 2.95 (1.68-5.17), respectively, for genotypes B and C. CONCLUSION: Serum sPD-1 levels may serve as a novel immunological predictor for spontaneous HBeAg seroclearance in patients with chronic hepatitis B.

Epidemiology of Virus Infection and Human Cancer.

Seven viruses including the Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), Kaposi's sarcoma herpes virus (KSHV), human immunodeficiency virus, type-1 (HIV-1), human T cell lymphotrophic virus, type-1 (HTLV-1), and human papillomavirus (HPV) have been classified as Group 1 human carcinogens by the International Agency for Research on Cancer (IARC). The conclusions are based on the findings of epidemiological and mechanistic studies. EBV, HPV, HTLV-1, and KSHV are direct carcinogens; HBV and HCV are indirect carcinogens through chronic inflammation; and HIV-1 is an indirect carcinogen through immune suppression. Some viruses may cause more than one cancer, while some cancers may be caused by more than one virus. However, only a proportion of persons infected by these oncogenic viruses will develop specific cancers. A series of studies have been carried out to assess the viral, host, and environmental cofactors of EBV-associated nasopharyngeal carcinoma, HBV/HCV-associated hepatocellular carcinoma, and HPV-associated cervical carcinoma. Persistent infection, high viral load, and viral genotype are important risk predictors of these virus-caused cancers. Risk calculators incorporating host and viral risk predictors have been developed for the prediction of long-term risk of hepatocellular carcinoma, nasopharyngeal carcinoma and cervical cancer. These risk calculators are useful for the triage and clinical management of infected patients. Both clinical trials and national programs of immunization, antiviral therapy and screening have demonstrated a significant reduction in the incidence of cancers caused by HBV, HCV, and HPV. Future research on gene-gene and gene-environment interactions of oncogenic viruses and the human host using large-scale longitudinal studies with serial measurements of biosignatures are in urgent need.

Level of Hepatitis B (HB) Core Antibody Associates With Seroclearance of HBV DNA and HB Surface Antigen in HB e Antigen-Seronegative Patients.

BACKGROUND & AIMS: Although a low level of hepatitis B surface antigen (HBsAg) is a marker of hepatitis B virus (HBV) seroclearance, additional biomarkers are needed for more accurate prediction. We investigated whether quantification of antibody against HBV core protein (anti-HBc) can identify patients with undetectable levels of HBV DNA and HBsAg seroclearance among those who were HBV e antigen (HBeAg)-seronegative. METHODS: We performed a retrospective analysis of data from a community-based cohort of individuals (30-65 years old) in Taiwan who were HBsAg seropositive, anti-HCV negative, and free of cirrhosis and/or liver cancer, recruited from 1991 through 1992, and evaluated every 6-12 months until June 30, 2004. We measured levels of anti-HBc in blood samples from 2500 participants who were seronegative for HBeAg. The first date at which a sample tested negative for HBV DNA or HBsAg, and remained negative in subsequent tests, was designated as the date of spontaneous HBV DNA undetectability or HBsAg seroclearance. We calculated cumulative incidences of HBV DNA undetectability and HBsAg seroclearance; associations between level of anti-HBc and undetectability of HBV DNA or HBsAg seroclearance were estimated by Cox proportional hazard regression. The effects of time on the associations between level of anti-HBc and HBsAg seroclearance was assessed by the area under the receiver operating characteristic curve (AUROC) analysis. RESULTS: After a 12-year follow-up period, higher proportions of subjects with levels of anti-HBc <3 log IU/mL had undetectable levels of HBV DNA (58%) and HBsAg seroclearance (53%) than subjects with higher levels of anti-HBc (29.6% and 19.8%, respectively) (P < .001). For subjects with levels of HBsAg <102 IU/mL and anti-HBc <3 log IU/mL, the adjusted rate ratio of HBV DNA undetectability was 16.45 (95% CI, 11.15-24.28) and of HBsAg seroclearance was 17.95 (95% CI, 12.49-25.81), compared to subjects with higher levels of HBsAg and anti-HBc. A model that included level of anti-HBc as a parameter identified subjects with HBsAg seroclearance within 10 years with an AUROC of 82%; this value was significantly higher than that from models that include only level of HBV DNA and HBsAg (P < .0001). CONCLUSIONS: In a retrospective analysis of a large cohort of patients with chronic HBV infection in Taiwan, we associated levels of anti-HBc <3 log IU/mL with undetectable HBV DNA and HBsAg seroclearance occurred within 10 years; patients who also have levels of HBsAg <102 IU/mL have greater odds. Combining data on levels of HBsAg, HBV DNA, and anti-HBc is able to identify HBeAg-seronegative patients who can achieve HBsAg seroclearance with an AUROC value of 82%.

Association Between High Levels of Hepatitis B Core Antibody and Seroclearance of Hepatitis B e Antigen in Individuals With Chronic Hepatitis B Virus Infection.

For chronic hepatitis B patients, hepatitis B e antigen (HBeAg) seroclearance signals a transition from an immunologically active phase to an inactive carrier state with a reduction in hepatitis B virus (HBV) DNA levels and a reduced risk of hepatocellular carcinoma (HCC).1 Predictors of HBeAg seroclearance include lower HBV DNA levels, viral genotype, the precore mutation, and higher serum alanine aminotransferase (ALT) levels.2.

A Glycomarker for Short-term Prediction of Hepatocellular Carcinoma: A Longitudinal Study With Serial Measurements.

OBJECTIVES: Wisteria floribunda agglutinin-positive human Mac-2-binding protein (WFA+-M2BP) is a glycomarker. The present community-based long-term follow-up study repeatedly determined the serum WFA+-M2BP level and examined its short- and long-term associations with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODS: A total of 921 participants with antibodies against HCV seropositive, but seronegative for hepatitis B surface antigen were enrolled from seven townships in Taiwan during 1991-1992. The participants were regularly followed and their serum WFA+-M2BP levels were measured at baseline and follow-up. HCC was ascertained through active follow-up and computerized data linkage with the National Cancer Registration System until December 31, 2013. Cox proportional hazards and logistic regression models were applied to estimate the magnitude of associations between serum WFA+-M2BP levels and HCC. RESULTS: During a median follow-up of 21.7 years, 122 new-onset HCC cases were identified. Elevated serum WFA+-M2BP levels were associated with an increased risk of HCC (p < 0.001). Patients with increasing changes in serum WFA+-M2BP levels, relative to their baseline levels, had a 4.36-fold risk of HCC. The areas under receiver operating curves (AUROCs) of WFA+-M2BP for predicting HCC showed that the prediction efficacy was significantly higher while closer to HCC diagnosis (p = 0.024). The AUROC was 0.91 for predicting HCC within 1 year by including the predictors of age, sex, alanine aminotransferase, alpha-fetoprotein (AFP) and WFA+-M2BP. CONCLUSIONS: Serum WFA+-M2BP level may elevate before HCC onset and is a short-term predictor of HCC among patients infected with HCV.

Serum Levels of M2BPGi as Short-Term Predictors of Hepatocellular Carcinoma in Untreated Chronic Hepatitis B Patients.

This study examines the role of M2BPGi, a novel seromarker for chronic hepatitis, in predicting hepatocellular carcinoma (HCC) among untreated chronic hepatitis B (CHB) patients. In this nested case-control study, 1070 samples were assayed for M2BPGi, including 357 samples from HCC cases, and 713 samples from non-HCC controls, collected at various times throughout follow-up. HCC case samples were stratified according to years prior to diagnosis. Associations between M2BPGi and HCC were examined with multivariate logistic regression. M2BPGi, α-fetoprotein (AFP), and hepatitis B surface antigen (HBsAg) levels were significant independent short-term predictors of HCC, while M2BPGi was insignificant in long-term analyses. Compared to M2BPGi levels <1.0 cut-off index (COI), those with levels ≥2.0 COI had multivariate odds ratios (95% CI) for HCC of 7.40 (2.40-22.78), 6.46 (2.58-16.18), and 2.24 (0.97-5.15), respectively, for prediction of HCC within 1-2, 2-5, and ≥5 years. Higher proportions of individuals had M2BPGi levels ≥2.0 COI in samples closer to HCC diagnosis. Areas under receiver operating characteristic curves for models with M2BPGi, AFP, and HBsAg levels predicting HCC within 1-2, 2-5, and >5 years were 0.84, 0.81, and 0.75. M2BPGi is a strong and independent short-term predictor of HCC in CHB patients.

Alcohol Drinking Mediates the Association between Polymorphisms of ADH1B and ALDH2 and Hepatitis B-Related Hepatocellular Carcinoma.

BACKGROUND: The role of polymorphisms on ADH1B and ALDH2 in patients with chronic hepatitis B is unclear. This study aims to examine whether alcohol drinking mediates the association between two ADH1B and ALDH2 polymorphisms and the risk of hepatocellular carcinoma among chronic hepatitis B patients. METHODS: A total of 3,824 individuals were enrolled in this study. Two SNPs, rs1229984 (ADH1B) and rs671 (ALDH2), were genotyped using the Affymetrix Axiom Genome-Wide CHB1 Array (Affymetrix, Inc). Multivariate unconditional logistic regression and mediation analyses were used, comparing CT or TT with CC for rs1229984 and GA and AA with GG for rs671. RESULTS: There were 602 cases of hepatocellular carcinoma and 3,222 controls. Frequencies of the rs1229984 (ADH1B) T allele and rs671 (ALDH2) A allele were 72.9% and 28.8%, respectively. Individuals who carried at least one deficient allele for both SNPs were significantly less likely to become habitual alcohol drinkers, with an OR and 95% confidence interval (CI) of 0.24 (0.15-0.40). Alleles for rs1229984 (ADH1B) and rs671 (ALDH2) were not associated with hepatocellular carcinoma in multivariate analyses. However, mediation analyses showed that the rs1229984 T allele, rs671 A allele, and two SNPs combined were significantly associated with decreased hepatocellular carcinoma risk, mediated through alcohol drinking, with an OR (95% CI) of 0.87 (0.79-0.96), 0.70 (0.61-0.82), and 0.73 (0.58-0.88), respectively. CONCLUSIONS: Polymorphisms on ADH1B and ALDH2 had significant indirect effects on hepatocellular carcinoma risk, mediated through alcohol drinking. IMPACT: Future genetic studies of chronic hepatitis B and hepatocellular carcinoma must take mediation effects into consideration. Cancer Epidemiol Biomarkers Prev; 25(4); 693-9. ©2016 AACR.

PARKIN Inactivation Links Parkinson's Disease to Melanoma.

BACKGROUND: Melanoma incidence is higher in patients affected by Parkinson's disease (PD) and vice versa, but the genetic link shared by both diseases is unknown. As PARK2 is both a tumor suppressor gene and frequently mutated in young onset PD, we evaluated the role of PARK2 in melanoma predisposition and progression. METHODS: An in-depth PARK2 gene dosage analysis and sequencing was performed on 512 French case patients and 562 healthy control patients, as well as sporadic tumors and melanoma cell lines. The frequency of genetic alterations was compared between case patients and control patients using two-sided Fisher's exact tests and odds ratio (OR) calculations. We used western blotting to determine PARKIN expression in melanocytes and melanoma cell lines and transfection followed by clonogenic assays to evaluate the effect of PARKIN expression on cellular proliferation. All statistical tests were two-sided. RESULTS: Germline PARK2 mutations (including copy number variations, splicing, and putative deleterious missense mutations) were present in 25 case patients but only four control patients (OR = 3.95, 95% confidence interval = 1.34 to 15.75). Copy number variations (CNVs) and loss of heterozygosity were present in 60% and 74%, respectively, of primary tumors. PARKIN protein was expressed in melanocytes but not in most melanoma cell lines, and its expression decreased following melanocyte transformation by oncogenic NRAS. Re-expression of PARKIN in melanoma cell lines resulted in a drastic reduction of cell proliferation and inhibition of PARKIN in melanocytes stimulated their proliferation. CONCLUSION: Our results show an important role for PARK2 as a tumor suppressor both in melanoma predisposition and progression, which could explain the epidemiological association of these diseases.

The rs2296651 (S267F) variant on NTCP (SLC10A1) is inversely associated with chronic hepatitis B and progression to cirrhosis and hepatocellular carcinoma in patients with chronic hepatitis B.

OBJECTIVE: The sodium taurocholate co-transporting polypeptide (NTCP), encoded by SLC10A1, was recently identified as a receptor for HBV. We assessed the association of the p.Ser267Phe variant (rs2296651) with chronic hepatitis B (CHB) serostatus, cirrhosis and hepatocellular carcinoma (HCC) in patients with CHB. DESIGN: The variant was genotyped in 3801 patients with CHB and 3801 matched hepatitis B surface antigen (HBsAg) seronegative individuals. ORs with 95% CIs for the variant's association with CHB, cirrhosis and HCC were estimated using logistic regression. RESULTS: In patients with CHB, the S267F variant was observed in 515 (18.5%) controls, 40 (17.2%) cirrhosis only cases, 49 (13.2%) non-cirrhotic HCC cases, and 52 (12.7%) cirrhotic-HCC cases. After adjustment for known risk factors, S267F was significantly associated with decreased risk for cirrhosis (OR 0.65 (95% CI 0.49 to 0.86), p=0.002) and HCC (OR 0.55 (95% CI 0.42 to 0.72), p<0.001). This association persisted for non-cirrhotic and cirrhotic-HCC. Compared with patients with HBV DNA levels greater than 10(5) copies/mL who carried the GG genotype, patients who had undetectable HBV DNA and the GA or AA genotypes had a 25-fold decreased risk of developing HCC (OR 0.04 (95% CI 0.02 to 0.11), p<0.001). The AA genotype was also associated with HBsAg seronegativity (OR 0.13 (95% CI 0.05 to 0.34), p<0.001). CONCLUSIONS: The SLC10A1 (NTCP) S267F variant is independently associated with decreased risk of cirrhosis and HCC, and resistance to CHB infection. Together with serum HBV DNA levels, S267F may help to identify patients with CHB with very low risk of HCC.

Genes involved in the WNT and vesicular trafficking pathways are associated with melanoma predisposition.

Multifactorial predisposition to melanoma includes genes involved in pigmentation, immunity and DNA repair. Nonetheless, missing heritability in melanoma is still important. We studied the role of 335 candidate SNPs in melanoma susceptibility by using a dedicated chip and investigating 110 genes involved in different pathways. A discovery set was comprised of 1069 melanoma patients and 925 controls from France. Data were replicated using validation phases II (1085 cases and 801 controls from Spain) and III (1808 cases and 1894 controls from Germany and a second set of Spanish samples). In addition, an exome sequencing study was performed in three high-risk French melanoma families. Nineteen SNPs in 17 genes were initially associated with melanoma in the French population. Six SNPs were replicated in phase II, including two new SNPs in the WNT3 (rs199524) and VPS41 (rs11773094) genes. The role of VPS41 and WNT3 was confirmed in a meta-analysis (3940 melanoma cases and 3620 controls) with two-side p values of 0.002, (OR = 0.86) and 4.07 × 10(-10) (OR = 0.80), respectively. Exome sequencing revealed a non-synonymous VPS41 variant in one family that was shown to be strongly associated with familial melanoma (OR = 4.46, p = 0.001) in an independent sample of 178 melanoma families. WNT3 belongs to WNT pathway known to play a crucial role in melanoma, whereas VPS41 regulates vesicular trafficking and is thought to play a role in pigmentation. Our work identified two new pathways involved in melanoma predisposition. These results may be useful in the future for identifying individuals highly predisposed to melanoma.

A large French case-control study emphasizes the role of rare Mc1R variants in melanoma risk.

BACKGROUND: The MC1R gene implicated in melanogenesis and skin pigmentation is highly polymorphic. Several alleles are associated with red hair and fair skin phenotypes and contribute to melanoma risk. OBJECTIVE: This work aims to assess the effect of different classes of MC1R variants, notably rare variants, on melanoma risk. Methods. MC1R coding region was sequenced in 1131 melanoma patients and 869 healthy controls. MC1R variants were classified as RHC (R) and non-RHC (r). Rare variants (frequency < 1%) were subdivided into two subgroups, predicted to be damaging (D) or not (nD). RESULTS: Both R and r alleles were associated with melanoma (OR = 2.66 [2.20-3.23] and 1.51 [1.32-1.73]) and had similar population attributable risks (15.8% and 16.6%). We also identified 69 rare variants, of which 25 were novel. D variants were strongly associated with melanoma (OR = 2.38 [1.38-4.15]) and clustered in the same MC1R domains as R alleles (intracellular 2, transmembrane 2 and 7). CONCLUSION: This work confirms the role of R and r alleles in melanoma risk in the French population and proposes a novel class of rare D variants as important melanoma risk factors. These findings may improve the definition of high-risk subjects that could be targeted for melanoma prevention and screening.

Germline BAP1 mutations predispose to renal cell carcinomas.

The genetic cause of some familial nonsyndromic renal cell carcinomas (RCC) defined by at least two affected first-degree relatives is unknown. By combining whole-exome sequencing and tumor profiling in a family prone to cases of RCC, we identified a germline BAP1 mutation c.277A>G (p.Thr93Ala) as the probable genetic basis of RCC predisposition. This mutation segregated with all four RCC-affected relatives. Furthermore, BAP1 was found to be inactivated in RCC-affected individuals from this family. No BAP1 mutations were identified in 32 familial cases presenting with only RCC. We then screened for germline BAP1 deleterious mutations in familial aggregations of cancers within the spectrum of the recently described BAP1-associated tumor predisposition syndrome, including uveal melanoma, malignant pleural mesothelioma, and cutaneous melanoma. Among the 11 families that included individuals identified as carrying germline deleterious BAP1 mutations, 6 families presented with 9 RCC-affected individuals, demonstrating a significantly increased risk for RCC. This strongly argues that RCC belongs to the BAP1 syndrome and that BAP1 is a RCC-predisposition gene.

Melanoma prone families with CDK4 germline mutation: phenotypic profile and associations with MC1R variants.

BACKGROUND: CDKN2A and CDK4 are high risk susceptibility genes for cutaneous malignant melanoma. Melanoma families with CDKN2A germline mutations have been extensively characterised, whereas CDK4 families are rare and lack a systematic investigation of their phenotype. METHODS: All known families with CDK4 germline mutations (n=17) were recruited for the study by contacting the authors of published papers or by requests via the Melanoma Genetics Consortium (GenoMEL). Phenotypic data related to primary melanoma and pigmentation characteristics were collected. The CDK4 exon 2 and the complete coding region of the MC1R gene were sequenced. RESULTS: Eleven families carried the CDK4 R24H mutation whereas six families had the R24C mutation. The total number of subjects with verified melanoma was 103, with a median age at first melanoma diagnosis of 39 years. Forty-three (41.7%) subjects had developed multiple primary melanomas (MPM). A CDK4 mutation was found in 89 (including 62 melanoma cases) of 209 tested subjects. CDK4 positive family members (both melanoma cases and unaffected subjects) were more likely to have clinically atypical nevi than CDK4 negative family members (p<0.001). MPM subjects had a higher frequency of MC1R red hair colour variants compared with subjects with one tumour (p=0.010). CONCLUSION: Our study shows that families with CDK4 germline mutations cannot be distinguished phenotypically from CDKN2A melanoma families, which are characterised by early onset of disease, increased occurrence of clinically atypical nevi, and development of MPM. In a clinical setting, the CDK4 gene should therefore always be examined when a melanoma family tests negative for CDKN2A mutation.

Genetic variation at KIT locus may predispose to melanoma.

As loss of KIT frequently occurs in melanoma progression, we hypothesized that KIT is implicated in predisposition to melanoma (MM). Thus, we sequenced the KIT coding region in 112 familial MM cases and 143 matched controls and genotyped tag single-nucleotide polymorphisms (SNPs) in two cohorts of melanoma patients and matched controls. Five rare KIT substitutions, all predicted possibly or probably deleterious, were identified in five patients, but none in controls [RR = 2.26 (1.26-2.26)]. Expressed in melanocyte lines, three substitutions inhibited KIT signaling. Comparison with exomes database (7020 alleles) confirmed a significant excess of rare deleterious KIT substitutions in patients. Additionally, a common SNP, rs2237028, was associated with MM risk, and 6 KIT variants were associated with nevus count. Our data strongly suggest that rare KIT substitutions predispose to melanoma and that common variants at KIT locus may also impact nevus count and melanoma risk.

MC1R, SLC45A2 and TYR genetic variants involved in melanoma susceptibility in southern European populations: results from a meta-analysis.

BACKGROUND AND METHODS: Seven genetic biomarkers previously associated with melanoma were analysed in a meta-analysis conducted in three South European populations: five red hair colour (RHC) MC1R alleles, one SLC45A2 variant (p.Phe374Leu) and one thermosensitive TYR variant (p.Arg402Gln). The study included 1639 melanoma patients and 1342 control subjects. RESULTS: The estimated odds ratio (OR) associated with carrying at least one MC1R RHC variant was 2.18 (95% confidence interval (CI): 1.86-2.55; p-value=1.02×10(-21)), with an additive effect for carrying two RHC variants (OR: 5.02, 95% CI: 2.88-8.94, p-value=3.91×10(-8)). The SLC45A2 variant, p.Phe374Leu, was significantly and strongly protective for melanoma in the three South European populations studied, with an overall OR value of 0.41 (95% CI: 0.33-0.50; p-value=3.50×10(-17)). The association with melanoma of the TYR variant p.Arg402Gln was also statistically significant (OR: 1.50; 95% CI: 1.11-2.04; p-value=0.0089). Adjustment for all clinical potential confounders showed that melanoma risks attributable to MC1R and SLC45A2 variants strongly persisted (OR: 2.01 95% CI: 1.49-2.72 and OR: 0.50, 95% CI: 0.31-0.80, respectively), while the association of TYR p.Arg402Gln was no longer significant. In addition, stratification of clinical melanoma risk factors showed that the risk of melanoma was strong in those individuals who did not have clinical risk factors. CONCLUSION: In conclusion, our results show without ambiguity that in South European populations, MC1R RHC and SCL45A2 p.Phe374Leu variants are strong melanoma risk predictors, notably in those individuals who would not be identified as high risk based on their phenotypes or exposures alone. The use of these biomarkers in clinical practice could be promising and warrants further discussion.

Assessment of tyrosinase variants and skin cancer risk in a large cohort of French subjects.

BACKGROUND: Tyrosinase (TYR) is a key pigmentation gene that is highly polymorphic and responsible for the most common form of autosomal recessive albinism, OCA1. OBJECTIVE: To assess the role of frequent and rare TYR variants in predisposition to skin cancer (SK) in the French population. METHODS: We genotyped a frequent TYR variant (p.R402Q) in 1273 patients {1047 cutaneous melanoma (CM) and 226 basal cell carcinoma (BCC)} and 925 controls, and the full coding region of TYR was sequenced in 287 patients suspected of genetic predisposition to SK (familial and/or multiple SK and/or onset before 40 years) and 187 controls. RESULTS: The homozygous p.R402Q variant was significantly associated with SK risk (P value=0.008; OR=1.57), and was mostly associated with multiple CM risk (P value=0.021; OR=2.50) and familial CM risk (P value=0.022; OR=2.16). In addition, 19 rare TYR variants, mainly albinism mutations, were identified in 15 patients and 8 controls. Among these, 3 clearly deleterious mutations (1 non-sense and 2 affecting mRNA splicing) were identified in 3 patients, one of which was homozygous. CONCLUSION: Our data confirmed the association of TYR p.R402Q with SK risk in the French population, and support that rare deleterious TYR variants may also play a role in multi-factorial genetic predisposition to SK. These results should be confirmed by replications studies.