Modulation by budesonide of DNA methylation and mRNA expression in mouse lung tumors

Biomarkers are being developed that can aid in the evaluation of cancer therapeutic and chemopreventive drugs. Two suggested biomarkers found in mouse lung tumors are DNA hypomethylation and alterations in mRNA expression of genes, such as 18S RNA, caspase 3, cyclin B2, cyclin E1, iNOS and survivin. Budesonide is very efficacious in preventing lung tumors in mice, so that its ability to modulate biomarkers in lung tumors was determined. Lung tumors were induced by vinyl carbamate in female strain A/J mice. Budesonide (2.0 mg/kg diet) was administered for 2, 7 and 21 days or for 14 days followed by a 7-days' holding period prior to the killing of the mice at week 27. After 2 days of budesonide treatment, the size of the lung tumors was reduced. Tumor size continued to decrease during the 21 days of treatment. In the tumors, 2 days of treatment resulted in (i) increased methylation of DNA, reversing DNA hypomethylation, (ii) increased expression of 18S RNA and (iii) decreased mRNA expression of caspase 3, cyclin B2, cyclin E1, iNOS and survivin. Termination of budesonide treatment at 7 days prior to killing did not affect the size of the tumors, but did result in increased mRNA expression of the 5 genes, approaching the expression level in tumors from control mice. Hence, budesonide rapidly decreased the size of lung tumors, reversed DNA hypomethylation and modulated mRNA expression of genes; with the molecular alterations requiring continued treatment with the drug for maintenance.     

DNA methylation changes measured in pre‐diagnostic peripheral blood samples are associated with smoking and lung cancer risk

DNA methylation changes are associated with cigarette smoking. We used the Illumina Infinium HumanMethylation450 array to determine whether methylation in DNA from pre‐diagnostic, peripheral blood samples is associated with lung cancer risk. We used a case‐control study nested within the EPIC‐Italy cohort and a study within the MCCS cohort as discovery sets (a total of 552 case‐control pairs). We validated the top signals in 429 case‐control pairs from another 3 studies. We identified six CpGs for which hypomethylation was associated with lung cancer risk: cg05575921 in the AHRR gene (p‐value_pooled = 4 × 10^?17), cg03636183 in the F2RL3 gene (p‐value_pooled = 2 × 10 ^{? 13}), cg21566642 and cg05951221 in 2q37.1 (p‐value_pooled = 7 × 10^?16 and 1 × 10^?11 respectively), cg06126421 in 6p21.33 (p‐value_pooled = 2 × 10^?15) and cg23387569 in 12q14.1 (p‐value_pooled = 5 × 10^?7). For cg05951221 and cg23387569 the strength of association was virtually identical in never and current smokers. For all these CpGs except for cg23387569, the methylation levels were different across smoking categories in controls (p‐values_{heterogeneity} ≤ 1.8 x10 ^{? 7}), were lowest for current smokers and increased with time since quitting for former smokers. We observed a gain in discrimination between cases and controls measured by the area under the ROC curve of at least 8% (p‐values ≥ 0.003) in former smokers by adding methylation at the 6 CpGs into risk prediction models including smoking status and number of pack‐years. Our findings provide convincing evidence that smoking and possibly other factors lead to DNA methylation changes measurable in peripheral blood that may improve prediction of lung cancer risk.     

Asbestos‐associated genome‐wide DNA methylation changes in lung cancer

Previous studies have revealed a robust association between exposure to asbestos and human lung cancer. Accumulating evidence has highlighted the role of epigenome deregulation in the mechanism of carcinogen‐induced malignancies. We examined the impact of asbestos on DNA methylation. Our genome‐wide studies (using Illumina HumanMethylation450K BeadChip) of lung cancer tissue and paired normal lung from 28 asbestos‐exposed or non‐exposed patients, mostly smokers, revealed distinctive DNA methylation changes. We identified a number of differentially methylated regions (DMR) and differentially variable, differentially methylated CpGs (DVMC), with individual CpGs further validated by pyrosequencing in an independent series of 91 non‐small cell lung cancer and paired normal lung. We discovered and validated BEND4, ZSCAN31 and GPR135 as significantly hypermethylated in lung cancer. DMRs in genes such as RARB (FDR 1.1 × 10^?19, mean change in beta [Δ] ?0.09), GPR135 (FDR 1.87 × 10^?8, mean Δ ?0.09) and TPO (FDR 8.58 × 10^?5, mean Δ ?0.11), and DVMCs in NPTN , NRG2 , GLT25D2 and TRPC3 (all with p <0.05, t‐test) were significantly associated with asbestos exposure status in exposed versus non‐exposed lung tumors. Hypomethylation was characteristic to DVMCs in lung cancer tissue from asbestos‐exposed subjects. When DVMCs related to asbestos or smoking were analyzed, 96% of the elements were unique to either of the exposures, consistent with the concept that the methylation changes in tumors may be specific for risk factors. In conclusion, we identified novel DNA methylation changes associated with lung tumors and asbestos exposure, suggesting that changes may be present in causal pathway from asbestos exposure to lung cancer.     

Estimation of the effects of smoking and DNA repair capacity on coefficients of a carcinogenesis model for lung cancer

Numerous prospective and retrospective studies have clearly demonstrated a dose‐related increased lung cancer risk associated with cigarette smoking, with evidence also for a genetic component to risk. In this study, using the two‐stage clonal expansion stochastic model framework, for the first time we investigated the roles of both genetic susceptibility and smoking history in the initiation, clonal expansion, and malignant transformation processes in lung carcinogenesis, integrating information collected by a case–control study and a large‐scale prospective cohort study. Our results show that individuals with suboptimal DNA repair capacity have enhanced transition rates of key events in carcinogenesis. © 2008 Wiley‐Liss, Inc.     

Serum carotenoid levels and risk of lung cancer death in US adults

Lung cancer is one of the most common cancers worldwide and is the leading cause of cancer‐induced death in the USA. Although much attention has been focused on the anti‐carcinogenic effect of consuming carotenoid‐containing food or supplements, the results have been inconsistent. We investigated whether serum carotenoid levels were associated with the mortality risk of lung cancer in US adults using data from a nationally representative sample. The data were obtained from the Third Nutrition and Health Examination Survey (NHANES III) database and the NHANES III Linked Mortality File. A total of 10 382 participants aged over 20 years with available serum carotenoid levels and no other missing information on questionnaires and biomarkers at baseline (NHANES III) were included in the present study. Of the 10 382 participants, 161 subjects died due to lung cancer. We found that high serum levels of alpha‐carotene and beta‐cryptoxanthin at baseline were significantly associated with a lower risk of lung cancer death. When we stratified the risk by current smoking status, the risk of death of current smokers was significantly decreased to 46% (95% confidence interval, 31–94%) for alpha‐carotene and 61% (95% confidence interval, 19–80%) for beta‐cryptoxanthin. By contrast, no association was observed among never/former smokers at baseline. High serum levels of alpha‐carotene and beta‐cryptoxanthin are associated with a lower risk of lung cancer death in US adults.     

DNA甲基化在肺癌中的研究进展

表观遗传学主要是研究基因表达的变化,而这种变化能够通过减数分裂遗传,但不涉及有关基因碱基序列的改变.随着肿瘤发病机制研究在分子生物学方面的逐步深入,发现DNA甲基化、非编码RNA表达调控和组蛋白的修饰等表观遗传学(epigenetics)改变引起的调控机制异常与人体多种恶性肿瘤的发生发展过程有着密切联系.研究表明抑癌基因启动子区高度DNA甲基化状态在恶性肿瘤的发生发展和侵袭转移中发挥着重要作用.在肺癌发生的早期,出现很多DNA甲基化状态的改变.因此,甲基化检测可能对肺癌患者的早期诊断、治疗及预后评估具有重要意义.     

DNA hypermethylation analysis in sputum for the diagnosis of lung cancer: training validation set approach

Background:

Lung cancer has the highest mortality of all cancers. The aim of this study was to examine DNA hypermethylation in sputum and validate its diagnostic accuracy for lung cancer.

Methods:

DNA hypermethylation of RASSF1A, APC, cytoglobin, 3OST2, PRDM14, FAM19A4 and PHACTR3 was analysed in sputum samples from symptomatic lung cancer patients and controls (learning set: 73 cases, 86 controls; validation set: 159 cases, 154 controls) by quantitative methylation-specific PCR. Three statistical models were used: (i) cutoff based on Youden''s J index, (ii) cutoff based on fixed specificity per marker of 96% and (iii) risk classification of post-test probabilities.

Results:

In the learning set, approach (i) showed that RASSF1A was best able to distinguish cases from controls (sensitivity 42.5%, specificity 96.5%). RASSF1A, 3OST2 and PRDM14 combined demonstrated a sensitivity of 82.2% with a specificity of 66.3%. Approach (ii) yielded a combination rule of RASSF1A, 3OST2 and PHACTR3 (sensitivity 67.1%, specificity 89.5%). The risk model (approach iii) distributed the cases over all risk categories. All methods displayed similar and consistent results in the validation set.

Conclusions:

Our findings underscore the impact of DNA methylation markers in symptomatic lung cancer diagnosis. RASSF1A is validated as diagnostic marker in lung cancer.     

Role of nitric oxide in genotoxicity: Implication for carcinogenesis

Reactive oxygen species can initiate carcinogenesis by virtue of their capacity to react with DNA and cause mutations. Recently, it has been suggested that nitric oxide (NO) and its derivatives produced in inflamed tissues could contribute to the carcinogenesis process. Genotoxicity of NO follows its reaction with oxygen and superoxide. It can be due either to direct DNA damage or indirect DNA damage. Direct damage includes DNA base deamination, peroxynitrite-induced adducts formation and single strand breaks in the DNA. Indirect damage is due to the interaction of NO reactive species with other molecules such as amines, thiols and lipids. The efficiency of one pathway or another might depend on the cellular antioxidant status or the presence of free metals.     

A snapshot of smokers after lung and colorectal cancer diagnosis

BACKGROUND:

Continued smoking after a cancer diagnosis may adversely affect treatment effectiveness, subsequent cancer risk, and survival. The prevalence of continued smoking after cancer diagnosis is understudied.

METHODS:

In the multi‐regional Cancer Care Outcomes Research and Surveillance cohort (lung cancer [N = 2456], colorectal cancer [N = 3063]), the authors examined smoking rates at diagnosis and 5 months after diagnosis and also study factors associated with continued smoking.

RESULTS:

Overall, 90.2% of patients with lung cancer and 54.8% of patients with colorectal cancer reported ever smoking. At diagnosis, 38.7% of patients with lung cancer and 13.7% of patients with colorectal cancer were smoking; whereas, 5 months after diagnosis, 14.2% of patients with lung cancer and 9.0% of patients with colorectal cancer were smoking. Factors that were associated independently with continued smoking among patients with nonmetastatic lung cancer were coverage by Medicare, other public/unspecified insurance, not receiving chemotherapy, not undergoing surgery, prior cardiovascular disease, lower body mass index, lower emotional support, and higher daily ever‐smoking rates (all P < .05). Factors that were associated independently with continued smoking among patients with nonmetastatic colorectal cancer were male sex, high school education, being uninsured, not undergoing surgery, and higher daily ever‐smoking rates (all P < .05).

CONCLUSIONS:

After diagnosis, a substantial minority of patients with lung and colorectal cancers continued smoking. Patients with lung cancer had higher rates of smoking at diagnosis and after diagnosis; whereas patients with colorectal cancer were less likely to quit smoking after diagnosis. Factors that were associated with continued smoking differed between lung and colorectal cancer patients. Future smoking‐cessation efforts should examine differences by cancer type, particularly when comparing cancers for which smoking is a well established risk factor versus cancers for which it is not. Cancer 2012;118: 3153–64. © 2012 American Cancer Society.     

Aberrant p16 promoter methylation in smokers and former smokers with nonsmall cell lung cancer

Hypermethylation of cytosines in CpG-rich islands of the promoter regions of regulatory genes has been discovered as a common mechanism of gene silencing during carcinogenesis. We analysed 64 primary lung carcinomas for promoter methylation of the tumour suppressor genes (TSGs) p16 (p16(INK4a)/CDKN2A) and p14 (p14(ARF)) by methylation-specific PCR, in order to evaluate aberrant methylation as a potential biomarker for epigenetic alterations in tobacco-related lung cancer. Methylation of p16 was observed in 34% (22/64) of the lung tumours examined. In particular, p16 methylation occurred in nonsmall cell lung cancer (NSCLC) only, with 41 % (22/54) of the tumours being positive. The highest frequency was found in large cell carcinoma (5/7, 71%), followed by adenocarcinoma (9/25, 36%) and squamous cell carcinoma (7/21, 33%). Methylation of the p14 gene was less frequent in lung cancer (4/52, 8%). When association with tobacco smoking was analysed, 42% (21/50) of NSCLC from ever smokers exhibited p16 methylation. Interestingly, the analysis revealed a significantly higher risk of p16 methylation in former smokers as compared to current smokers [odds ratio (OR) 5.1; 95% confidence interval (CI) 1.3-22]. The difference was retained after adjustment for age (OR 3.7; 95% CI 0.9-17). The promoter methylation results were then combined with data on genetic alterations determined previously in the same set of tumours. This data similarly showed that p16 methylation in parallel with p53 gene mutation or p14 methylation occurred more frequently in former smokers than in current smokers (44% vs. 14%; P = 0.035). Taken together, our data suggest that analysis of promoter methylation in TSGs may provide a valuable biomarker for identification of groups with an elevated risk of cancer, such as smokers and ex-smokers.     

Smoke exposure,histologic type and geography-related differences in the methylation profiles of non-small cell lung cancer

Aberrant methylation of several known or putative tumor suppressor genes occurs frequently during the pathogenesis of lung cancers. There are major smoke exposure, histology, geography and gender-related changes in non-small cell lung cancer (NSCLC). We investigated smoking-related, histologic, geographic and gender differences in the methylation profiles of resected NSCLCs. We examined 514 cases of NSCLC and 84 corresponding nonmalignant lung tissues from 4 countries (USA, Australia, Japan and Taiwan) for the methylation status of 7 genes known to be frequently methylated in lung cancers [p16, RASSF1A (RAS association domain family 1), APC, RARbeta, CDH13, MGMT and GSTP1]. Multivariate analyses were used for data analysis. Adenocarcinoma was the major histologic type in women and never smokers; analyses that involved smoke exposure and gender were limited to this histology. Our major findings are a) methylation status of any single gene was largely independent of methylation status of other genes; b) the rates of methylation of p16 and APC and the mean Methylation Index (MI), a reflection of the overall methylation status, were significantly higher in ever smokers than in never smokers; c) the mean MI of tumors arising in former smokers was significantly lower than the mean of current smokers; d) the methylation rates of APC, CDH13 and RARbeta were significantly higher in adenocarcinomas than in squamous cell carcinomas; e) methylation rates of MGMT and GSTP1 were significantly higher in the USA and Australian cases than in those from Japan and Taiwan; and (f) no significant gender-related differences in methylation patterns were noted. Our findings demonstrate important smoke exposure, histologic type and geography-related differences in the methylation profiles of NSCLC tumors.     

Haptoglobin and posttranslational glycan-modified derivatives as serum biomarkers for the diagnosis of nonsmall cell lung cancer

BACKGROUND: The purpose was to evaluate the clinical utility of serum haptoglobin (Hp) and posttranslational glycan modifications of Hp for the diagnosis of nonsmall cell lung cancer (NSCLC). METHODS: Serum proteins from patients with a new diagnosis of NSCLC and age- and sex-matched controls without cancer were compared using 2-dimensional difference gel electrophoresis (2D-DIGE). Four of the differentially expressed gel spots were identified as the beta chain of Hp. Immunoblots confirmed sialyl and fucosyl group posttranslational modifications (PTMs) of Hp. Serum enzyme-linked immunosorbent assays (ELISAs) for total Hp, sialylated Hp (SAHp), and fucosylated Hp (FHp) were designed, and levels of each were measured in an independent sample set of 74 patients. Receiver operating characteristic (ROC) analysis assessed the clinical diagnostic utility of each marker. RESULTS: Statistically significant differences between lung cancer patients and matched controls were found by ELISA for Hp (P < .002), SAHp (P < .001), and FHp (P < .04). ROC analysis determined an area under the curve (AUC) of 0.754 for Hp, 0.740 for SAHp, and 0.794 for FHp. In addition, serum concentrations correlated with stage; Hp (r = 0.388; P = .018), SAHp (r = 0.300; P = .072), and FHp (r = 0.363; P = .027). CONCLUSIONS: Hp and 2 of its glycoforms, SAHp and FHp, are potentially useful in the clinical diagnosis of NSCLC. The markers increase with stage, suggesting they may also be useful in stratifying patients at presentation and in following patients after treatment.     

F2RL3 methylation,lung cancer incidence and mortality

Smoking accounts for a large share of lung cancer. F2RL3 methylation was recently identified as a biomarker closely reflecting both current and past smoking exposure. We aimed to assess the associations of F2RL3 methylation with lung cancer incidence and mortality. In a large population‐based cohort study, F2RL3 methylation was measured in baseline blood samples of 4,987 participants by MassARRAY. Associations of F2RL3 methylation and smoking with lung cancer incidence/mortality during a median follow‐up of 10.9 years were assessed by Cox regression, controlling for potential confounders. The ability of F2RL3 methylation to predict lung cancer was examined by Harrell's C statistics. Hypomethylation at F2RL3 was strongly associated with both lung cancer incidence and mortality, with age‐ and sex‐adjusted hazard ratios (HR; 95% CI) of 9.99 (5.61–17.79) and 16.86 (8.53–33.34), respectively, for participants whose methylation intensity were ≤0.54 compared with whose methylation intensity were ≥0.75. Strongly elevated HRs of 2.88 (1.42–5.84) and 5.17 (2.28–11.70) persisted even after controlling for multiple covariates including smoking status and pack‐years. With fully adjusted HRs of 9.92 (2.88–34.12) and 16.48 (4.10–66.15), the associations between methylation and the two outcomes were particularly strong among participants≥65 years. Combination of F2RL3 methylation and pack‐years predicted lung cancer incidence with high accuracy (optimism‐corrected Harrell's C statistics = 0.86 for participants≥65 years). These findings suggested that F2RL3 methylation is a very strong predictor of lung cancer risk and mortality, particularly at older age. The potential implications of F2RL3 methylation for early detection, risk stratification and prevention of lung cancer warrant further exploration.     

hOGG1 Ser326Cys polymorphism and G:C-to-T:A mutations: no evidence for a role in tobacco-related non small cell lung cancer

Human 8-oxoguanine DNA glycosylase 1 (hOGG1) plays a major role in the repair of 8-hydroxyguanine, one of the major forms of DNA damage generated by reactive oxygen species in tobacco smoke. If left unrepaired by hOGG1, 8-hydroxyguanine can produce G:C-to-T:A transversions. Recent studies have suggested that the hOGG1 Ser326Cys polymorphism is associated with both a decrease in enzyme activity and an increased risk of lung cancer. To define the interaction between tobacco carcinogens, hOGG1-mediated DNA repair and DNA damage, we examined the role of the hOGG1 Ser326Cys polymorphism in mutation of the p53 gene in non small cell lung cancer (NSCLC). Tumor and nonneoplastic DNA were collected from 141 cigarette smokers with NSCLC. p53 mutations were detected by direct dideoxy sequencing and/or the GeneChip p53 assay in 74 of the 141 (52%) tumors. hOGG1 codon 326 polymorphisms were identified by polymerase chain reaction-restriction fragment length polymorphism analysis. The distribution of hOGG1 codon 326 genotypes was Ser/Ser, 90 of 141 (64%); Ser/Cys, 45 of 141 (32%); and Cys/Cys, 6 of 141 (4%). p53 mutations were significantly (p = 0.04) less common in NSCLC from patients with codon 326 Ser/Cys or Cys/Cys genotypes (21 of 51; 41%) than in NSCLC from Ser/Ser homozygotes (53 of 90; 59%). The decrease in p53 mutation frequency among carriers of the Cys allele was more evident in lung squamous cell cancer [7 of 17 (41%) for Cys/Cys and Ser/Cys vs. 27 of 38 (71%) for Ser/Ser; p = 0.04] than in nonbronchoalveolar adenocarcinoma [11 of 26 (42%) for Cys/Cys and Ser/Cys vs. 20 of 35 (57%) for Ser/Ser; p = 0.25]. The prevalence of G:C-to-T:A transversions was similar among hOGG1 codon 326 genotypes. In summary, the hOGG1 codon 326 Cys allele was associated with a decrease in p53 mutations and no effect on G:C-to-T:A transversions in NSCLC. This decrease in p53 mutations in vivo is not consistent with a decrease in the repair of 8-hydroxyguanine among carriers of the hOGG1 codon 326 Cys allele in vitro.     

影像组学在非小细胞肺癌诊疗中的应用进展

影像组学作为一种新兴技术,能够用以检出结节,区分良恶性病变,甚至预测病灶组织学分期以及基因型。当其被应用于非小细胞肺癌治疗中时,可以提高疗效评估准确率以及预测复发风险。影像组学有望越来越多地影响非小细胞肺癌的临床治疗实践,优化端到端的诊疗随访链条,本文现对非小细胞肺癌影像组学最新研究现状做一综述。     

The cumulative risk of lung cancer among current, ex- and never-smokers in European men

Recent analyses based on UK data indicate that people who stop smoking, even well into middle age, avoid most of their subsequent risk of lung cancer. We investigated whether similar absolute risks of lung cancer in men are found in other European countries with different smoking patterns and at different stages of their lung cancer epidemic. Using data for men from a multicentre case-control study of lung cancer in the UK, Germany, Italy and Sweden, and including 6523 lung cancer cases and 9468 controls, we combined odds ratio estimates with estimates of national lung cancer incidence rates to calculate the cumulative risk of lung cancer among men by age 75. Lung cancer cumulative risks by age 75 among continuing smokers were similar for the UK, Germany and Italy at 15.7, 14.3 and 13.8% respectively, whereas the cumulative risk among Swedish male smokers was 6.6%. The proportion of the risk of lung cancer avoided by quitting smoking before the age of 40 was comparable between the four countries, at 80% in Italy and 91% in the UK, Germany and Sweden. Similarly, the proportion of the excess risk avoided by quitting before the age of 50 ranged from 57% in Italy to 69% in Germany. Our results support the important conclusion that for long-term smokers, giving up smoking in middle age avoids most of the subsequent risk of lung cancer, and that lung cancer mortality in European men over the next three decades will be determined by the extent to which current smokers can successfully quit smoking.     

Cannabis smoking and lung cancer risk: Pooled analysis in the International Lung Cancer Consortium

To investigate the association between cannabis smoking and lung cancer risk, data on 2,159 lung cancer cases and 2,985 controls were pooled from 6 case‐control studies in the US, Canada, UK, and New Zealand within the International Lung Cancer Consortium. Study‐specific associations between cannabis smoking and lung cancer were estimated using unconditional logistic regression adjusting for sociodemographic factors, tobacco smoking status and pack‐years; odds‐ratio estimates were pooled using random effects models. Subgroup analyses were done for sex, histology and tobacco smoking status. The shapes of dose‐response associations were examined using restricted cubic spline regression. The overall pooled OR for habitual versus nonhabitual or never users was 0.96 (95% CI: 0.66–1.38). Compared to nonhabitual or never users, the summary OR was 0.88 (95%CI: 0.63–1.24) for individuals who smoked 1 or more joint‐equivalents of cannabis per day and 0.94 (95%CI: 0.67–1.32) for those consumed at least 10 joint‐years. For adenocarcinoma cases the ORs were 1.73 (95%CI: 0.75–4.00) and 1.74 (95%CI: 0.85–3.55), respectively. However, no association was found for the squamous cell carcinoma based on small numbers. Weak associations between cannabis smoking and lung cancer were observed in never tobacco smokers. Spline modeling indicated a weak positive monotonic association between cumulative cannabis use and lung cancer, but precision was low at high exposure levels. Results from our pooled analyses provide little evidence for an increased risk of lung cancer among habitual or long‐term cannabis smokers, although the possibility of potential adverse effect for heavy consumption cannot be excluded.     

Race- and age-dependent alterations in global methylation of DNA in squamous cell carcinoma of the lung (United States)

Objective: The current study investigated the race- and age-dependent alterations in global DNA methylation on the development and progression of squamous cell carcinomas (SCCs) of the lung. Methods: Methylation status was evaluated in SCC and in the associated uninvolved bronchial mucosa (UBM) and epithelial hyperplasia (EH) of 53 Whites and 23 African Americans by using an antibody specific for 5-methylcytosine (5-mc). A low 5-mc score indicates global hypomethylation of DNA. Results: 5-mc scores of SCC were significantly lower compared to 5-mc scores of UBM and EH in Whites (p < 0.05). In African Americans, 5-mc scores of SCCs were not significantly different from 5-mc scores of UBM and EH, suggesting an involvement of methylation in the development of SCCs in Whites, but not in African Americans. 5-mc scores were lower in younger subjects compared to older subjects in Whites. Since cancers in younger subjects tend to be more aggressive than cancers in older subjects, these observations may suggest that hypomethylation may have contributed to aggressiveness cancers of younger Whites. Hypomethylation of SCCs in White men was associated with shorter survival from the disease. Conclusions: These preliminary results suggest that the methylation status of DNA may affect the development, aggressiveness, and prognosis of SCCs in Whites.