Risk factors for hepatocellular carcinoma (HCC) in the northeast of the United States: results of a case-control study.

PURPOSE: HCC incidence has been continuously rising in the US for the past 30 years. To understand the increase in HCC risk, we conducted a case-control study in Connecticut, New Jersey and part of New York City. METHODS: Through rapid case ascertainment and random digit dialing, we recruited 673 incident HCC patients and 1,166 controls. Information on demographic and anthropometric characteristics, lifestyle factors, medical and family cancer histories, were ascertained through telephone interviews using a structured questionnaire. Saliva specimens were collected for testing hepatitis C virus (HCV) antibodies. Unconditional logistic regression models were utilized to calculate odds ratio (OR) and 95% confidence interval (CI) to determine HCC associations with risk factors. RESULTS: The study confirmed that HCV infection and obesity were important risk factors for HCC, ORs 110 (95% CI 59.2-204) and 2.13 (95% CI 1.52-3.00), respectively. High BMI and HCV infection had synergy in association with elevated HCC risk. Patients both obese and infected with HCV had HCC detected on average nearly 10 years earlier than those with neither factor. Diabetes, cigarette smoking and heavy alcohol intake were all associated with increased risk of HCC, whereas aspirin and other NSAID use were associated with reduced risk. HCC cases tended to attain less education, with lower household incomes, unmarried, and to have had more sexual partners than the controls. CONCLUSIONS: Individuals at risk of HCC in the US comprise a unique population with low socioeconomic status and unhealthy lifestyle choices. Given the multifactorial nature, a comprehensive approach is needed in HCC prevention.

Serum 25-hydroxyvitamin D, vitamin D binding protein, and prostate cancer risk in black men.

BACKGROUND: Few studies have prospectively examined the relationship between vitamin D status and prostate cancer risk in black men, a group at high risk for both low vitamin D status and prostate cancer. METHODS: Among black men in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we identified 226 prostate cancer cases and 452 controls matched on age at randomization (±5 years), date of blood draw (±30 days), calendar year of cohort entry, and time since baseline prostate cancer screening (±1 year). Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between serum 25-hydroxyvitamin D [25(OH)D], vitamin D binding protein (DBP), the 25(OH)D:DBP molar ratio, and prostate cancer risk. RESULTS: Serum 25(OH)D was not associated with overall prostate cancer (Q4 vs Q1: OR, 0.73; 95% CI, 0.40-1.33; P for trend = .25), although there were apparent inverse associations for nonaggressive disease (global P = .03, clinical stage I/II, and Gleason score <7) and among men ≥62 years old (P for interaction = .04) that were restricted to Q3. Interestingly, serum DBP was significantly inversely associated with prostate cancer risk (Q4 vs Q1: OR, 0.45; 95% CI, 0.20-1.00; P for trend = .03), whereas the 25(OH)D:DBP molar ratio was not. Results were similar when we mutually adjusted for 25(OH)D and DBP, and we found no evidence of interaction between the two. CONCLUSION: Our study suggests higher (versus lower) circulating DBP may be independently associated with a decreased prostate cancer risk in black men independent of 25(OH)D status. Cancer 2017;123:2698-704. © 2017 American Cancer Society.

Pre-diagnosis diet and survival after a diagnosis of ovarian cancer.

BACKGROUND: The relationship between diet and survival after ovarian cancer diagnosis is unclear as a result of a limited number of studies and inconsistent findings. METHODS: We examined the association between pre-diagnostic diet and overall survival in a population-based cohort (n=811) of Australian women diagnosed with invasive epithelial ovarian cancer between 2002 and 2005. Diet was measured by validated food frequency questionnaire. Deaths were ascertained up to 31 August 2014 via medical record review and Australian National Death Index linkage. We conducted Cox proportional hazards regression analysis, controlling for diagnosis age, tumour stage, grade and subtype, residual disease, smoking status, body mass index, physical activity, marital status, and energy intake. RESULTS: We observed improved survival with highest compared with lowest quartile of fibre intake (hazard ratio (HR)=0.69, 95% CI: 0.53-0.90, P-trend=0.002). There was a suggestion of better survival for women with highest compared with lowest intake category of green leafy vegetables (HR=0.79, 95% CI: 0.62-0.99), fish (HR=0.74, 95% CI: 0.57-0.95), poly- to mono-unsaturated fat ratio (HR=0.76, 95% CI: 0.59-0.98), and worse survival with higher glycaemic index (HR=1.28, 95% CI: 1.01-1.65, P-trend=0.03). CONCLUSIONS: The associations we observed between healthy components of diet pre-diagnosis and ovarian cancer survival raise the possibility that dietary choices after diagnosis may improve survival.

The Association Between Alcohol Consumption and Lung Carcinoma by Histological Subtype.

Alcohol is a carcinogen suspected of increasing lung cancer risk. Therefore, we prospectively evaluated the relationship between alcohol consumption and lung carcinoma in 492,902 persons from the National Institutes of Health-AARP Diet and Health Study. We used Cox models to calculate hazard ratios and 95% confidence intervals, adjusting for tobacco smoking and other potential confounders. Between 1995/1996 and December 31, 2006, there were 10,227 incident cases of lung carcinoma, classified as adenocarcinoma (n = 4,036), squamous cell carcinoma (n = 1,998), small cell carcinoma (n = 1,524), undifferentiated carcinoma (n = 559), and other (n = 2,110). Compared with nondrinking, alcohol consumption was associated with a modest nonlinear reduction in total lung carcinoma risk at lower levels of consumption (for 0.5-<1 drink/day, HR = 0.89, 95% confidence interval: 0.82, 0.96) but a modest increase in risk in the highest category (for ≥7 drinks/day, HR = 1.11, 95% confidence interval: 1.00, 1.24). Regarding histological type, alcohol was associated with a nonlinear reduction in squamous cell carcinoma that became attenuated as consumption increased and a modest increase in adenocarcinoma among heavier drinkers. Cubic spline models confirmed these findings. Our data suggest that the relationship between alcohol consumption and lung carcinoma differs by histological subtype.

Association of Coffee Consumption With Overall and Cause-Specific Mortality in a Large US Prospective Cohort Study.

Concerns about high caffeine intake and coffee as a vehicle for added fat and sugar have raised questions about the net impact of coffee on health. Although inverse associations have been observed for overall mortality, data for cause-specific mortality are sparse. Additionally, few studies have considered exclusively decaffeinated coffee intake or use of coffee additives. Coffee intake was assessed at baseline by self-report in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Hazard ratios were estimated using Cox proportional hazards models. Among 90,317 US adults without cancer at study baseline (1998-2001) or history of cardiovascular disease at study enrollment (1993-2001), 8,718 deaths occurred during 805,644 person-years of follow-up from 1998 through 2009. Following adjustment for smoking and other potential confounders, coffee drinkers, as compared with nondrinkers, had lower hazard ratios for overall mortality (<1 cup/day: hazard ratio (HR) = 0.99 (95% confidence interval (CI): 0.92, 1.07); 1 cup/day: HR = 0.94 (95% CI: 0.87, 1.02); 2-3 cups/day: HR = 0.82 (95% CI: 0.77, 0.88); 4-5 cups/day: HR = 0.79 (95% CI: 0.72, 0.86); ≥6 cups/day: HR = 0.84 (95% CI: 0.75, 0.95)). Similar findings were observed for decaffeinated coffee and coffee additives. Inverse associations were observed for deaths from heart disease, chronic respiratory diseases, diabetes, pneumonia and influenza, and intentional self-harm, but not cancer. Coffee may reduce mortality risk by favorably affecting inflammation, lung function, insulin sensitivity, and depression.

Indoor tanning and the MC1R genotype: risk prediction for basal cell carcinoma risk in young people.

Basal cell carcinoma (BCC) incidence is increasing, particularly in young people, and can be associated with significant morbidity and treatment costs. To identify young individuals at risk of BCC, we assessed existing melanoma or overall skin cancer risk prediction models and built a novel risk prediction model, with a focus on indoor tanning and the melanocortin 1 receptor gene, MC1R. We evaluated logistic regression models among 759 non-Hispanic whites from a case-control study of patients seen between 2006 and 2010 in New Haven, Connecticut. In our data, the adjusted area under the receiver operating characteristic curve (AUC) for a model by Han et al. (Int J Cancer. 2006;119(8):1976-1984) with 7 MC1R variants was 0.72 (95% confidence interval (CI): 0.66, 0.78), while that by Smith et al. (J Clin Oncol. 2012;30(15 suppl):8574) with MC1R and indoor tanning had an AUC of 0.69 (95% CI: 0.63, 0.75). Our base model had greater predictive ability than existing models and was significantly improved when we added ever-indoor tanning, burns from indoor tanning, and MC1R (AUC = 0.77, 95% CI: 0.74, 0.81). Our early-onset BCC risk prediction model incorporating MC1R and indoor tanning extends the work of other skin cancer risk prediction models, emphasizes the value of both genotype and indoor tanning in skin cancer risk prediction in young people, and should be validated with an independent cohort.

Novel gene identified in an exome-wide association study of tanning dependence.

Growing evidence suggests that some individuals may exhibit symptoms of dependence to ultraviolet light, a known carcinogen, in the context of tanning. Genetic associations with tanning dependence (TD) have not yet been explored. We conducted an exome-wide association study in 79 individuals who exhibited symptoms of TD and 213 individuals with volitional exposure to ultraviolet light, but who were not TD based on three TD scales. A total of 300 000 mostly exomic single nucleotide polymorphisms primarily in coding regions were assessed using an Affymetrix Axiom array. We performed a gene burden test with Bonferroni correction for the number of genes examined (P < 0.05/14 904 = 3.36 × 10(-6) ). One gene, patched domain containing 2 (PTCHD2), yielded a statistically significant P-value of 2.5 × 10(-6) (OR = 0.27) with fewer individuals classified as TD having a minor allele at this locus. These results require replication, but are the first to support a specific genetic association with TD.

Indoor tanning in businesses and homes and risk of melanoma and nonmelanoma skin cancer in 2 US case-control studies.

BACKGROUND: Indoor tanning increases skin cancer risk. Beyond early research describing melanoma and sun lamps, few recent reports describe where individuals indoor tan and whether skin cancer risk varies by location (business, home-based). OBJECTIVE: We sought to assess where individuals tanned indoors and skin cancer risk by tanning device location. METHODS: Multivariate logistic regression was conducted in 2 US case-control studies of melanoma (1161 cases, 1083 controls, ages 25-59 years) and early-onset basal cell carcinoma (375 cases, 382 controls, age<40 years) conducted between 2004 and 2010. RESULTS: Most indoor tanners (86.4%-95.1%), especially younger individuals, tanned exclusively in businesses. Persons who used indoor tanning exclusively in businesses were at increased risk of melanoma (odds ratio 1.82, 95% confidence interval 1.47-2.26) and basal cell carcinoma (odds ratio 1.69, 95% confidence interval 1.15-2.48) compared with non-users. Melanoma risk was also increased in the small number who reported tanning indoors only at home relative to non-users (odds ratio 4.14, 95% confidence interval 1.75-9.78); 67.6% used sun lamps. LIMITATIONS: Self-reported tanning and potential recall bias are limitations. CONCLUSION: Business-only tanning, despite claims of "safe" tanning, was positively associated with a significant risk of melanoma and basal cell carcinoma. Home tanning was uncommon and mostly from sun lamps, which were rarely used by younger participants. Regardless of location, indoor tanning was associated with increased risk of skin cancer.

Smoking cessation is followed by increases in serum bilirubin, an endogenous antioxidant associated with lower risk of lung cancer and cardiovascular disease.

INTRODUCTION: Lower concentrations of serum bilirubin, an endogenous antioxidant, have been associated with risk of many smoking-related diseases, including lung cancer and cardiovascular disease, and current smokers are reported to have lower bilirubin levels than nonsmokers and past smokers. This study evaluates the effects of smoking cessation on bilirubin levels. METHODS: In a secondary analysis of a 6-week placebo-controlled trial of naltrexone for smoking cessation, indirect and total bilirubin concentrations were evaluated at baseline and following smoking cessation. Individuals who were continuously abstinent for 6 weeks (n = 155) were compared to those who were not (n = 193). Participants reported smoking ≥ 20 cigarettes daily at baseline and received smoking cessation counseling, 21 mg nicotine patch daily, and either placebo or 1 of 3 doses of naltrexone (25, 50, or 100mg) for 6 weeks. Change in indirect and total bilirubin following the quit date was measured at Weeks 1, 4, and 6 compared to baseline. RESULTS: Individuals who were continuously abstinent from smoking, independent of naltrexone condition, showed a significantly greater mean increase in indirect (~unconjugated) bilirubin (0.06 mg/dl, SD = 0.165) compared to those who did not (mean = 0.02, SD = 0.148, p = .015). Similar results were obtained for total bilirubin (p = .037). CONCLUSIONS: Smoking cessation is followed by increases in bilirubin concentration that have been associated with lower risk of lung cancer and cardiovascular disease.

Lessons learned from randomized clinical trials of micronutrient supplementation for cancer prevention.

This review discusses the results of randomized clinical trials of supplemental micronutrients for cancer prevention completed over the past 20 years, including trials of beta-carotene and retinol, vitamins C and E, selenium, folic acid, and vitamin D. Some trials observed significant reductions in risk, whereas others observed significant increases in risk of the primary cancer endpoint. In considering these trials, it appears that supplementation targeted to populations with low status of the nutrient of interest may prevent cancer, whereas supplementation in populations with higher status or to achieve pharmacological exposures may promote cancer. Observational epidemiologic evidence coupled with these trial results supports the concept of a U-shaped curve for micronutrients in relation to cancer prevention. Based on these data, nutrient supplements are not currently recommended for cancer prevention in the general population. The hypothesis that groups with low nutrient status may benefit from supplementation has yet to be formally tested.

Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies.

Resonance Raman spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes.

Single v. multiple measures of skin carotenoids by resonance Raman spectroscopy as a biomarker of usual carotenoid status.

Resonance Raman spectroscopy (RRS) is a non-invasive method of assessing carotenoid status in the skin, which has been suggested as an objective indicator of fruit/vegetable intake. The present study assessed agreement and identified predictors of single v. multiple RRS measures of skin carotenoid status. A total of seventy-four participants had their skin carotenoid status measured in the palm of the hand by RRS at six time points over 6 months. Questionnaires were administered to collect information on demographic, lifestyle and dietary data. Mean age of the participants was 36.6 years, 62.2% were female, 83.8% Caucasian and 85.1% were non-smoking at baseline. There was a good agreement between a single measure of skin carotenoids by RRS and multiple measures (weighted κ = 0.80; 95% CI 0.72, 0.88). The same variables were significantly associated with carotenoid status based on single or multiple measures, including a positive association with intake of total carotenoids (P< 0.01) and an inverse association with season of measurement (P≤ 0.05). The exception was recent sun exposure, which emerged as a significant predictor of lower carotenoid status only when using multiple RRS measures (P≤ 0.01). A single RRS measure was reasonably accurate at classifying usual skin carotenoid status. Researchers using RRS may want to take into account other factors that are associated with the biomarker, including season of measurement and recent sun exposure.

Dietary fiber intake and risk of breast cancer by menopausal and estrogen receptor status.

PURPOSE: Evaluate the hypothesis that relation of breast cancer associated with dietary fiber intakes varies by type of fiber, menopausal, and the tumor's hormone receptor status. METHODS: A case-control study of female breast cancer was conducted in Connecticut. A total of 557 incident breast cancer cases and 536 age frequency-matched controls were included in the analysis. Information on dietary intakes was collected through in-person interviews with a semi-quantitative food frequency questionnaire and was converted into nutrient intakes. Odds ratios and 95% confidence intervals were estimated by unconditional logistic regression. RESULTS: Among pre-menopausal women, higher intake of soluble fiber (highest versus lowest quartile of intake) was associated with a significantly reduced risk of breast cancer (OR = 0.38, 95% CI, 0.15-0.97, P (trend) = 0.08). When further restricted to pre-menopausal women with ER(-) tumors, the adjusted OR for the highest quartile of intake was 0.15 (95% CI, 0.03-0.69, P (trend) = 0.02) for soluble fiber intake. Among post-menopausal women, no reduced risk of breast cancer was observed for either soluble or insoluble fiber intakes or among ER(+) or ER(-) tumor groups. CONCLUSIONS: The results from this study show that dietary soluble fiber intake is associated with a significantly reduced risk of ER(-) breast cancer among pre-menopausal women. Additional studies with larger sample size are needed to confirm these results.

Omega-3 and omega-6 fatty acid intakes and endometrial cancer risk in a population-based case-control study.

PURPOSE: Animal and laboratory studies suggest that long-chain omega-3 (n-3) fatty acids, a type of polyunsaturated fat found in fatty fish, may protect against carcinogenesis, but human studies on dietary intake of polyunsaturated fats and fish with endometrial cancer risk show mixed results. METHODS: We evaluated the associations between endometrial cancer risk and intake of fatty acids and fish in a population-based sample of 556 incident cancer cases and 533 age-matched controls using multivariate unconditional logistic regression methods. RESULTS: Although total n-3 fatty acid intake was not associated with endometrial cancer risk, higher intakes of eicosapentaenoic (EPA 20:5) and docosahexaenoic (DHA 22:6) fatty acids were significantly associated with lower risks (OR = 0.57, 95 % CI: 0.39-0.84; OR = 0.64, 95 % CI: 0.44-0.94; respectively) comparing extreme quartiles. The ratio of n-3:n-6 fatty acids was inversely associated with risk only on a continuous scale (OR = 0.84, 95 % CI: 0.71-0.99), while total fish intake was not associated with risk. Fish oil supplement use was significantly associated with reduced risk of endometrial cancer: OR = 0.63 (95 % CI: 0.45-0.88). CONCLUSIONS: Our results suggest that dietary intake of the long-chain polyunsaturated fatty acids EPA and DHA in foods and supplements may have protective associations against the development of endometrial cancer.

Functional study of risk loci of stem cell-associated gene lin-28B and associations with disease survival outcomes in epithelial ovarian cancer.

Several single-nucleotide polymorphisms (SNPs) of the stem cell-associated gene lin-28B have been identified in association with ovarian cancer and ovarian cancer-related risk factors. However, whether these SNPs are functional or might be potential biomarkers for ovarian cancer prognosis remains unknown. The purposes of this study were to investigate the functional relevance of the identified lin-28B SNPs, as well as the associations of genotype and phenotype with epithelial ovarian cancer (EOC) survival. We analyzed five SNPs and mRNA levels of lin-28B in 211 primary EOC tissues using Taqman(®) SNP genotyping assays and SYBR green-based real-time PCR, respectively. The RNA secondary structures at the region of a genome-wide association-identified intronic rs314276 were analyzed theoretically with mfold and experimentally with circular dichroism spectroscopy. We found that rs314276 was a cis-acting expression quantitative trait locus (eQTL) in both additive and dominant models, while rs7759938 and rs314277 were significant or of borderline significance in dominant models only. The rs314276 variant significantly affects RNA secondary structure. No SNPs alone were associated with patient survival. However, we found that among patients initially responding to chemotherapy, those with higher lin-28B expression had higher mortality risk (hazard ratio =3.27, 95% confidence interval: 1.63-6.56) and relapse risk (hazard ratio = 2.53, 95% confidence interval: 1.41-4.54) than those with lower expression, and these associations remained in multivariate analyses. These results suggest that rs314276 alters RNA secondary structure and thereby influences gene expression, and that lin-28B is a cancer stem cell-associated marker, which may be a pharmaceutical target in the management of EOC.

Association of large noncoding RNA HOTAIR expression and its downstream intergenic CpG island methylation with survival in breast cancer.

Large noncoding RNA HOTAIR, transcribed from the antisense strand of HOXC12, interacts with Polycomb Repressive Complex 2 (PRC2) in the regulation of gene activities. Recent work suggests that it may have effects on breast cancer progression and survival. We evaluated HOTAIR expression and the methylation status of its downstream intergenic CpG island in primary breast cancers, and examined associations of these factors with clinical and pathologic features and patient survival. HOTAIR expression and DNA methylation were analyzed in tissue from 348 primary breast cancers with quantitative RT-PCR and methylation-specific PCR, respectively. HOTAIR expression and methylation varied widely in the tissues. A positive correlation was found between DNA methylation and HOTAIR expression. Methylation was associated with unfavorable disease characteristics, whereas no significant associations were found between HOTAIR expression and clinical or pathologic features. In multivariate, but not in univariate, Cox proportional hazard regression models, patients with high HOTAIR expression had lower risks of relapse and mortality than those with low HOTAIR expression. These findings suggest that the intergenic DNA methylation may have important biologic relevance in regulating HOTAIR expression, and that HOTAIR expression may not be an independent prognostic marker in breast cancer, but needs further validation in independent studies.

Indoor tanning and risk of early-onset basal cell carcinoma.

BACKGROUND: Despite an increase in incidence of basal cell carcinoma (BCC) among young people and the ubiquity of indoor tanning in this population, few epidemiologic studies have investigated this exposure-disease relationship. OBJECTIVE: We sought to evaluate the association between indoor tanning and early-onset BCC. METHODS: Patients with BCC (n = 376) and control subjects with minor benign skin conditions (n = 390) who were younger than 40 years of age were identified through Yale Dermatopathology. Participants provided information on ever indoor tanning, age of initiation, frequency, duration, burns while tanning, and type of tanning device during an in-person interview. We calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariate logistic regression with never indoor tanners as the referent group. RESULTS: Ever indoor tanning was associated with a 69% increased risk of early-onset BCC (95% CI 1.15-2.48). This association was stronger among females (OR 2.14, 95% CI 1.31-3.47), for multiple BCCs (OR 2.16, 95% CI 1.26-3.70), and for BCCs on the trunk and extremities (OR 2.81, 95% CI 1.57-5.02). Risk increased dose dependently with years using regular indoor tanning devices (P trend = .003), number of overall burns (P trend < .001), and burns to biopsy site (P trend < .001) from indoor tanning. Approximately one quarter (27%) of early-onset BCCs (or 43% among women) could be prevented if individuals never tanned indoors. LIMITATIONS: Potential recall bias of indoor tanning by patients and generalizability of the control population suggest replication in other studies is warranted. CONCLUSIONS: Indoor tanning was a strong risk factor for early-onset BCC, particularly among females. Indoor tanning should continue to be targeted by both policy-based and behavioral interventions, as the impact on BCC-associated morbidity may be substantial.

Lifetime history of indoor tanning in young people: a retrospective assessment of initiation, persistence, and correlates.

BACKGROUND: Despite educational and public health campaigns to convey the risks of indoor tanning, many individuals around the world continue to engage in this behavior. Few descriptive studies of indoor tanning have collected information pertaining to the lifetime history of indoor tanning, thereby limiting our ability to understand indoor tanning patterns and potentially target interventions for individuals who not only initiate, but continue to persistently engage in indoor tanning. METHODS: In-person interviews elicited detailed retrospective information on lifetime history of indoor tanning among white individuals (n = 401) under age 40 seen by a dermatologist for a minor benign skin condition. These individuals were controls in a case-control study of early-onset basal cell carcinoma. Outcomes of interest included ever indoor tanning in both males and females, as well as persistent indoor tanning in females - defined as females over age 31 who tanned indoors at least once in the last three or all four of four specified age periods (ages 11-15, 16-20, 21-30 and 31 or older). Multivariate logistic regression was used to identify sociodemographic and lifestyle correlates of ever and persistent indoor tanning in females. RESULTS: Approximately three-quarters (73.3%) of females and 38.3% of males ever tanned indoors, with a median age of initiation of 17.0 and 21.5, respectively. Among indoor tanners, 39.3% of females and 21.7% of males reported being burned while indoor tanning. Female ever indoor tanners were younger, had darker color eyes, and sunbathed more frequently than females who never tanned indoors. Using unique lifetime exposure data, 24.7% of female indoor tanners 31 and older persistently tanned indoors starting as teenagers. Female persistent indoor tanners drank significantly more alcohol, were less educated, had skin that tanned with prolonged sun exposure, and sunbathed outdoors more frequently than non-persistent tanners. CONCLUSIONS: Indoor tanning was strikingly common in this population, especially among females. Persistent indoor tanners had other high-risk behaviors (alcohol, sunbathing), suggesting that multi-faceted behavioral interventions aimed at health promotion/disease prevention may be needed in this population.