Ann E. Perry

Genus β human papillomaviruses and incidence of basal cell and squamous cell carcinomas of skin: population based case-control study

Objective To investigate the association between genus β human papillomaviruses and the incidence of non-melanocytic skin cancer in the general population. Design Population based case-control study. Setting New Hampshire, USA. Participants 2366 skin cancer cases and controls from the general population aged 25 to 74 years (663 squamous cell carcinoma, 898 basal cell carcinoma, 805 controls), with plasma samples tested for L1 antibodies to 16 genus β human papillomaviruses by multiplex serology. Main outcome measures Odds ratios for squamous cell carcinoma and basal cell carcinoma associated with seropositivity to β human papillomaviruses. Results Squamous cell carcinoma, but not basal cell carcinoma, cases had a higher prevalence of each of the individual β human papillomaviruses assayed compared with controls. The odds ratios for squamous cell carcinoma increased with the number of β types positive (odds ratio for one type positive 0.99 (95% confidence interval 0.74 to 1.33); two to three types positive 1.44 (1.03 to 2.01); four to eight types positive 1.51 (1.03 to 2.20); more than eight types positive 1.71 (1.12 to 2.62); P for trend (categorical)<0.001; P for trend (continuous)=0.003). With limited statistical power, the association was stronger among long term users of systemic glucocorticoids (odds ratio 3.21, 1.22 to 8.44) than among non-users (1.23, 0.97 to 1.55). Conclusions These findings support a relation between genus β human papillomavirus infection and the incidence of squamous cell carcinoma of the skin in the general population, as well as potential enhancement of risk by immunosuppression.

Microsatellite instability at tetranucleotide repeats in skin and bladder cancer

Recently, a novel form of MSI has been described that occurs only at tetranucleotide repeat markers. This has been termed elevated microsatellite instability at selected tetranucleotide repeats (EMAST). EMAST has been related to alterations of the p53 gene, and to the nature of the repeat sequence. We initially tested whether loss of heterozygosity (LOH) at the p53 and the patched (ptch) genes was related to EMAST in a series of 61 non-melanoma skin cancer (NMSC) tumors. We then analysed a series of 57 primary bladder cancers for the presence of EMAST, testing whether this was related to mutation or expression of the p53 gene. In both NMSC and bladder tumors we found a high prevalence of EMAST (75.4 and 43.9%). In NMSC the prevalence of EMAST was higher in tumors that had either p53 or ptch LOH, although the difference was not statistically significant. There was a significant association of extensive EMAST (three or more loci) with mutations in p53 among the bladder cancer tumors, but no indication of elevated EMAST in tumors with abnormal p53 staining without mutation. The association of EMAST with p53 mutation was confined to non-invasive disease. Hence, EMAST likely reflects a particular pattern of somatic events that are interactive with p53 mutation, particularly common in skin cancer and limited to non-invasive disease in bladder cancer.

Pigmentary characteristics and moles in relation to melanoma risk

Although benign and atypical moles are considered key melanoma risk factors, previous studies of their influence were small and/or institution‐based. We conducted a population‐based case‐control study in the state of New Hampshire. Individuals of ages 20–69 with an incident diagnosis of first primary cutaneous melanoma were ascertained through the New Hampshire State Cancer Registry. Controls were identified through New Hampshire drivers license lists and frequency‐matched by age and gender to cases. We interviewed 423 eligible cases and 678 eligible controls. Host characteristics, including mole counts, were evaluated using logistic regression analyses. Our results showed that pigmentary factors, including eye color (OR = 1.57 for blue eyes compared to brown), hair color (OR = 1.85 for blonde/red hair color compared to brown/black), freckles before age 15 (OR = 2.39 for freckles present compared to absent) and sun sensitivity (OR = 2.25 for peeling sunburn followed by no tan or a light tan and 2.42 for sunburn followed by tan compared to tanning immediately), were related to melanoma risk; these associations held after adjustment for sun‐related factors and for moles. In analyses confined to skin examination participants, the covariate‐adjusted effects of benign and atypical moles were moderately strong. Compared to 0–4 benign moles, risk increased steadily for 5–14 moles (OR = 1.71), 15–24 moles (OR = 3.55) and ≥ 25 moles (OR = 4.33). Risk also increased with the number of atypical moles; compared to none, the ORs for having 1, 2–3, or ≥ 4 atypical moles were 2.08, 1.84 and 3.80, respectively. Although risk was highest for those with multiple benign and atypical moles, the interaction was not of statistical significance. Our findings, arising from the first population‐ and incidence‐based study to evaluate atypical moles in relation to melanoma risk, confirm the importance of host susceptibility, represented by pigmentary factors and the tendency to develop benign or atypical moles, in the etiology of this disease.

Exposure Profiles and Human Papillomavirus Infection in Skin Cancer: An Analysis of 25 Genus β-Types in a Population-Based Study

An increasing number of studies report that genus beta human papillomaviruses (HPVs) are associated with skin cancer, with suggestions of specificity for squamous cell carcinoma (SCC) of the skin. We have conducted a systematic examination of HPV DNA in tumors from immunocompetent hosts, including SCC and basal cell carcinoma (BCC), using a highly sensitive methodology and population-based samples to test the hypothesis that a differential prevalence of beta-HPVs exists between SCC (n=101) and BCC (n=101) tumors. When testing for all known beta-HPV types, we found no significant difference in HPV prevalence between the two histologies. However, SCC lesions were significantly more likely to be infected with HPV genus beta-species 1 (includes types 5 and 8), than BCC samples (P=0.01); this difference was not observed for any other species. A histologic difference was also observed for those HPV types previously reported to be important in skin cancer (P=0.003). SCC samples showed a higher rate of infectivity (that is, were positive for multiple types) than BCC tumors (P=0.02). These data highlight the potential importance of various genus beta-HPV types, in particular genus beta-species 1 in SCC, and support the hypothesis of a behavioral difference of the virus within the two major histological skin cancers.

Photosensitizing Agents and the Risk of Non-Melanoma Skin Cancer: A Population-Based Case–Control Study

It is well-known that ultraviolet (UV) light exposure and a sun sensitive phenotype are risk factors for the development of non-melanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). In this New Hampshire population-based case-control study, we collected data from 5,072 individuals, including histologically-confirmed cases of BCC and SCC, and controls via a personal interview to investigate possible associations between photosensitizing medication use and NMSC. After adjustment for potentially confounding factors (e.g. lifetime number of painful sunburns), we found a modest increase in risk of SCC (OR = 1.2, 95% CI = 1.0–1.4) and BCC (OR = 1.2, 95% CI = 0.9–1.5), in particular early-onset BCC, (≤ 50 years of age) (OR = 1.5, 95% CI = 1.1–2.1) associated with photosensitizing medication use. For SCC the association was strongest amongst those with tendency to sunburn rather than tan. We also specifically found associations with BCC, and especially early-onset BCC, and photosensitizing antimicrobials. In conclusion, certain commonly prescribed photosensitizing medications may enhance the risk of developing SCC, especially in individuals with a sun sensitive phenotype, and may increase the risk of developing BCC and incidence of BCC at a younger age.

Cutaneous alpha, beta and gamma human papillomaviruses in relation to squamous cell carcinoma of the skin: A population-based study

Human papillomavirus (HPV) infection is common worldwide and, in immunodeficient populations, may contribute to the pathogenesis of keratinocyte cancers, particularly squamous cell carcinomas (SCC). However, their role in SCC in the general population is less clear. We conducted a comprehensive analysis to investigate the independent effects of seropositivity for cutaneous alpha, beta and gamma HPV types on risk of SCC, and a meta‐analysis of the available literature. In a population‐based case‐control study from New Hampshire, USA (n = 1,408), histologically confirmed SCC cases and controls were tested for L1 antibodies to alpha, beta and gamma cutaneous HPV types 2–5, 7–10, 15, 17, 20, 23, 24, 27b, 36, 38, 48–50, 57, 65, 75–77, 88, 92, 95, 96, 101, 103 and 107 using multiplex serology. An increasing risk of SCC with number of beta HPVs to which an individual tested positive was observed even among those seronegative for gamma types (p for trend = 0.016) with an odds ratio of 1.95 (95% confidence interval (CI) = 1.07–3.56) for four or more beta types positive. In a meta‐analysis of six case‐control studies, increased SCC risks in relation to beta HPV seropositivity were found across studies (meta odds ratio = 1.45, CI = 1.27–1.66). While the prevalence of gamma HPVs assayed was somewhat higher among SCC cases than controls, the association was only weakly evident among those seronegative for beta HPVs. Overall, the association between cutaneous HPVs and skin cancers appears to be specific to SCC and to genus beta HPVs in a general US population.

CTLA4 Variants, UV-Induced Tolerance, and Risk of Non-Melanoma Skin Cancer

Although skin tumors are highly immunogenic, exposure to UV radiation is known to suppress immune responses via regulatory T cells. Specifically, the activity of cytotoxic lymphocyte-associated antigen-4 (CTLA-4) is integral in regulating the development of UV-induced tolerance and, concomitantly, skin cancers. Due to the inverse relationship between tumor surveillance and autoimmunity, we hypothesize that the same genetic variant in the CTLA4 locus that increases risk for autoimmune diseases is associated with decreased risk of non-melanoma skin cancer (NMSC). We analyzed whether the polymorphism CT60 or haplotypes of CTLA4 influence odds of developing the major types of NMSC, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), in a population-based case-control study of Caucasians in New Hampshire (849 controls, 930 BCC, and 713 SCC). The CTLA4 CT60 GG genotype was associated with decreased odds for BCC and SCC, controlling for age, sex, lifetime number of severe sunburns, and skin type [BCC: odds ratio (OR), 0.7; 95% confidence interval (95% CI), 0.5-0.9; SCC: OR, 0.7; 95% CI, 0.5-1.0]. For BCC, this decrease was apparent largely among those with a higher lifetime number of severe sunburns (P(interaction) = 0.0074). There were significantly decreased odds of disease associated with two haplotypes, which possess the CT60 G allele. Additionally, lifetime number of severe sunburns modestly altered the effects of the CTLA4 haplotypes in BCC, and the association seemed driven by the CT60 single nucleotide polymorphism. In conclusion, genetic variation at the CTLA4 locus may be etiologically important in NMSC, the most prevalent malignancy in the United States.

A population-based case-control study of urinary arsenic species and squamous cell carcinoma in New Hampshire, USA

Background: Chronic high arsenic exposure is associated with squamous cell carcinoma (SCC) of the skin, and inorganic arsenic (iAs) metabolites may play an important role in this association. However, little is known about the carcinogenicity of arsenic at levels commonly observed in the United States. Objective: We estimated associations between total urinary arsenic and arsenic species and SCC in a U.S. population. Methods: We conducted a population-based case–control SCC study (470 cases, 447 controls) in a U.S. region with moderate arsenic exposure through private well water and diet. We measured urinary iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), and summed these arsenic species (ΣAs). Because seafood contains arsenolipids and arsenosugars that metabolize into DMA through alternate pathways, participants who reported seafood consumption within 2 days before urine collection were excluded from the analyses. Results: In adjusted logistic regression analyses (323 cases, 319 controls), the SCC odds ratio (OR) was 1.37 for each ln-transformed microgram per liter increase in ln-transformed ΣAs concentration [ln(ΣAs)] (95% CI: 1.04, 1.80). Urinary ln(MMA) and ln(DMA) also were positively associated with SCC (OR = 1.34; 95% CI: 1.04, 1.71 and OR = 1.34; 95% CI: 1.03, 1.74, respectively). A similar trend was observed for ln(iAs) (OR = 1.20; 95% CI: 0.97, 1.49). Percent iAs, MMA, and DMA were not associated with SCC. Conclusions: These results suggest that arsenic exposure at levels common in the United States relates to SCC and that arsenic metabolism ability does not modify the association. Citation: Gilbert-Diamond D, Li Z, Perry AE, Spencer SK, Gandolfi AJ, Karagas MR. 2013. A population-based case–control study of urinary arsenic species and squamous cell carcinoma in New Hampshire, USA. Environ Health Perspect 121:1154–1160; http://dx.doi.org/10.1289/ehp.1206178

A role for ultraviolet radiation immunosuppression in non-melanoma skin cancer as evidenced by gene–environment interactions

The genotoxic effects of ultraviolet (UV) radiation are well-known causes of skin cancers; however, UV radiation also suppresses the immune system, decreasing the bodys surveillance for tumor cells. In experimental systems, UV radiation immunosuppression is at least partially mediated through urocanic acid (UCA), an UV radiation-absorbing molecule in the stratum corneum. We tested the hypothesis that genetic variation in the histidase gene (HAL), which catalyzes the formation of UCA in the skin, modifies risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in a population-based study (914 BCC, 702 SCC and 848 controls). We observed no evidence of a main gene effect for the HAL I439V polymorphism (rs7297245) and BCC or SCC. However, we found a HAL genotype-sunburn interaction in association with BCC (P for interaction = 0.040) and SCC (P for interaction = 0.018). A HAL genotype-SCC association was observed primarily among women (odds ratio = 1.5, 95% confidence interval 1.1-2.2), and among women, we found an interaction between HAL genotype and oral contraceptive use on SCC risk (P = 0.040). The variant HAL allele likewise appeared to modify the SCC risk associated with glucocorticoid steroid usage (P for interaction = 0.0004). In conclusion, our findings are a first step in determining the genetic underpinnings of UV immune suppression and have identified important new genetic interactions contributing to the etiology of skin cancer.

Genetic Determinants of UV-Susceptibility in Non-Melanoma Skin Cancer

A milieu of cytokines and signaling molecules are involved in the induction of UV-induced immune suppression and thus the etiology of non-melanoma skin cancer (NMSC). Targeting the UV-induced immunosuppression pathway, and using a large population based study of NMSC, we have investigated the risk associated with functional variants in 10 genes (IL10, IL4, IL4R, TNF, TNFR2, HTR2A, HRH2, IL12B, PTGS2, and HAL). The most prominent single genetic effect was observed for IL10. There was increasing risk for both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) with increasing number of variant IL10 haplotypes (BCC: ptrend = 0.0048; SCC: ptrend = 0.031). Having two IL10 GC haplotypes was associated with increased odds ratios of BCC and SCC (ORBCC = 1.5, 95% CI 1.1–1.9; ORSCC = 1.4, 95% CI 1.0–1.9), and these associations were largely confined to women (ORBCC = 2.2, 95% CI 1.4–3.4; SCC: ORSCC = 1.8, 95% CI 1.1–3.0). To examine how combinations of these variants contribute to risk of BCC and SCC, we used multifactor dimensionality reduction (MDR) and classification and regression trees (CART). Results from both of these methods found that in men, a combination of skin type, burns, IL10, IL4R, and possibly TNFR2 were important in both BCC and SCC. In women, skin type, burns, and IL10 were the most critical risk factors in SCC, with risk of BCC involving these same factors plus genetic variants in HTR2A, IL12B and IL4R. These data suggest differential genetic susceptibility to UV-induced immune suppression and skin cancer risk by gender.