588Plasma concentrations of persistent organic pollutants and pancreatic cancer risk

Background

Findings and limitations of previous studies on persistent organic pollutants (POPs) and pancreatic cancer risk support conducting further research in prospective cohorts.

Objective

To investigate the association between plasma concentrations of selected POPs and pancreatic cancer risk.

Methods

Prospective case-control study nested within the EPIC cohort. Participants were 513 pancreatic cancer cases and 1020 matched controls. Concentrations of 22 POPs (organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers) were measured in plasma collected at baseline by GC-MS/MS.

Results

Some, generally moderate effects were observed at higher concentrations of p,p’-DDT, trans-nonachlor, β-hexachlorocyclohexane, and the sum of 6 organochlorine pesticides and of 16 POPs. The odds ratio (OR) for the upper quartile of trans-nonachlor was 1.55 (95% confidence interval 1.06 to 2.26; P for trend=0.025). Associations were stronger in the groups predefined as most valid or relevant. Among participants having fasted >6 hours at blood collection, the ORs were significant for 10 of 11 exposure categories. Higher ORs were also observed among cases with microscopic confirmation than in cases with a clinical diagnosis. Higher ORs were also observed among normal-weight participants, with relevant estimates for all 11 exposure categories. Among participants with a follow-up ≥10 years, estimates were also higher (e.g., for trans-nonachlor: OR = 2.14, 1.01 to 4.53, P for trend=0.035). Overall, trans-nonachlor, 3 PCBs, and the 2 sums of POPs were the exposures more clearly associated with pancreatic cancer risk.

Conclusions

A few moderately increased risks were apparent for the highest concentrations of certain POPs, sometimes with a dose-response relationship.

Integration of multiomic annotation data to prioritize and characterize inflammation and immune-related risk variants in squamous cell lung cancer

Clinical trial results have recently demonstrated that inhibiting inflammation by targeting the interleukin-1β pathway can offer a significant reduction in lung cancer incidence and mortality, highlighting a pressing and unmet need to understand the benefits of inflammation-focused lung cancer therapies at the genetic level. While numerous genome-wide association studies (GWAS) have explored the genetic etiology of lung cancer, there remains a large gap between the type of information that may be gleaned from an association study and the depth of understanding necessary to explain and drive translational findings. Thus, in this study we jointly model and integrate extensive multiomics data sources, utilizing a total of 40 genome-wide functional annotations that augment previously published results from the International Lung Cancer Consortium (ILCCO) GWAS, to prioritize and characterize single nucleotide polymorphisms (SNPs) that increase risk of squamous cell lung cancer through the inflammatory and immune responses. Our work bridges the gap between correlative analysis and translational follow-up research, refining GWAS association measures in an interpretable and systematic manner. In particular, reanalysis of the ILCCO data highlights the impact of highly associated SNPs from nuclear factor-κB signaling pathway genes as well as major histocompatibility complex mediated variation in immune responses. One consequence of prioritizing likely functional SNPs is the pruning of variants that might be selected for follow-up work by over an order of magnitude, from potentially tens of thousands to hundreds. The strategies we introduce provide informative and interpretable approaches for incorporating extensive genome-wide annotation data in analysis of genetic association studies.

Incidence and Survival Trends of Pancreatic Cancer in Girona: Impact of the Change in Patient Care in the Last 25 Years

(1) Background: We investigated the incidence and survival trends for pancreatic cancer (PC) over the last 25 years in the Girona region, Catalonia, Spain; (2) Methods: Data were extracted from the population-based Girona Cancer Registry. Incident PC cases during 1994–2015 were classified using the International Classification of Diseases for Oncology Third Edition (ICD-O-3). Incidence rates age-adjusted to the European standard population (ASR_E) and world standard population (ASR_W) were obtained. Trends were assessed using the estimated annual percentage of change (EAPC) of the ASR_E13. Observed and relative survivals (RS) were estimated with the Kaplan–Meier and Pohar Perme methods, respectively; (3) Results: We identified 1602 PC incident cases. According to histology, 44.4% of cases were exocrine PC, 4.1% neuroendocrine, and 51.1% malignant-non-specified. The crude incidence rate (CR) for PC was 11.43 cases-per-100,000 inhabitants/year. A significant increase of incidence with age and over the study period was observed. PC overall 5-year RS was 7.05% (95% confidence interval (CI) 5.63; 8.84). Longer overall survival was observed in patients with neuroendocrine tumours (5-year RS 61.45%; 95% CI 47.47; 79.55). Trends in 5-year RS for the whole cohort rose from 3.27% (95% CI 1.69–6.35) in 1994–1998 to 13.1% (95% CI 9.98; 17.2) in 2010–2015; (4) Conclusions: Incidence rates of PC in Girona have increased in the last two decades. There is a moderate but encouraging increase in survival thorough the study period. These results can be used as baseline for future research.

Fine mapping of MHC region in lung cancer highlights independent susceptibility loci by ethnicity

The basis for associations between lung cancer and major histocompatibility complex genes is not completely understood. Here the authors further consider genetic variation within the MHC region in lung cancer patients and identify independent associations within HLA genes that explain MHC lung cancer associations in Europeans and Asian populations.

Lung cancer has several genetic associations identified within the major histocompatibility complex (MHC); although the basis for these associations remains elusive. Here, we analyze MHC genetic variation among 26,044 lung cancer patients and 20,836 controls densely genotyped across the MHC, using the Illumina Illumina OncoArray or Illumina 660W SNP microarray. We impute sequence variation in classical HLA genes, fine-map MHC associations for lung cancer risk with major histologies and compare results between ethnicities. Independent and novel associations within HLA genes are identified in Europeans including amino acids in the HLA-B*0801 peptide binding groove and an independent HLA-DQB1*06 loci group. In Asians, associations are driven by two independent HLA allele sets that both increase risk in HLA-DQB1*0401 and HLA-DRB1*0701; the latter better represented by the amino acid Ala-104. These results implicate several HLA–tumor peptide interactions as the major MHC factor modulating lung cancer susceptibility.

Pleiotropy of genetic variants on obesity and smoking phenotypes: Results from the Oncoarray Project of The International Lung Cancer Consortium

Obesity and cigarette smoking are correlated through complex relationships. Common genetic causes may contribute to these correlations. In this study, we selected 241 loci potentially associated with body mass index (BMI) based on the Genetic Investigation of ANthropometric Traits (GIANT) consortium data and calculated a BMI genetic risk score (BMI-GRS) for 17,037 individuals of European descent from the Oncoarray Project of the International Lung Cancer Consortium (ILCCO). Smokers had a significantly higher BMI-GRS than never-smokers (p = 0.016 and 0.010 before and after adjustment for BMI, respectively). The BMI-GRS was also positively correlated with pack-years of smoking (p<0.001) in smokers. Based on causal network inference analyses, seven and five of 241 SNPs were classified to pleiotropic models for BMI/smoking status and BMI/pack-years, respectively. Among them, three and four SNPs associated with smoking status and pack-years (p<0.05), respectively, were followed up in the ever-smoking data of the Tobacco, Alcohol and Genetics (TAG) consortium. Among these seven candidate SNPs, one SNP (rs11030104, BDNF) achieved statistical significance after Bonferroni correction for multiple testing, and three suggestive SNPs (rs13021737, TMEM18; rs11583200, ELAVL4; and rs6990042, SGCZ) achieved a nominal statistical significance. Our results suggest that there is a common genetic component between BMI and smoking, and pleiotropy analysis can be useful to identify novel genetic loci of complex phenotypes.

History of allergy and atopic dermatitis in relation to squamous cell and Basal cell carcinoma of the skin

BACKGROUND

Little is known about whether history of allergies and atopy is related to the occurrence of keratinocyte cancers. Thus, we evaluated the association between history of allergies and atopy and the incidence of squamous cell carcinoma (SCC) and early onset basal cell carcinoma (BCC).

METHODS

As part of a population-based case-control study, interviews were conducted with 1,050 residents of New Hampshire (375 early onset BCC cases and 251 controls, 254 SCC cases and 432 controls). ORs of SCC and early onset BCC and history of allergy and atopic dermatitis were computed using logistic regression, while controlling for potential confounding factors.

RESULTS

An overall inverse association was observed between a history of allergy and early onset BCC [OR, 0.61; 95% confidence interval (CI), 0.38-0.97] but not SCC (OR, 1.18; 95% CI, 0.78-1.79). Among women, we found reduced ORs of both early onset BCC and of SCC in relation to allergy history (early onset BCC OR, 0.53; 95% CI, 0.31-0.92 and SCC OR, 0.59; 95% CI, 0.29-1.19). Among men, we observed no clear association with early onset BCC (OR, 0.87; 95% CI, 0.39-1.99) and an increased risk of SCC (OR, 1.58; 95% CI, 0.93-2.69).

CONCLUSION

Our findings suggest that allergies and atopy may influence risk of early onset BCC and SCC, and that effects may be gender specific.

IMPACT

A deeper understanding of the immune mechanisms underlying allergies and atopy may provide new routes of preventing keratinocyte cancers.

Reproductive risk factors and endometrial cancer: the European Prospective Investigation into Cancer and Nutrition

Endometrial cancer risk has been associated with reproductive factors (age at menarche, age at menopause, parity, age at first and last birth, time since last birth and use of oral contraceptives (OCs)]. However, these factors are closely interrelated and whether they act independently still requires clarification. We conducted a study to examine the association of menstrual and reproductive variables with the risk of endometrial cancer among the European Prospective Investigation into Cancer and Nutrition (EPIC). Among the 302,618 women eligible for the study, 1,017 incident endometrial cancer cases were identified. A reduction in endometrial cancer risk was observed in women with late menarche, early menopause, past OC use, high parity and a shorter time since last full-term pregnancy (FTP). No association was observed for duration of breast feeding after adjustment for number of FTP or for abortion (spontaneous or induced). After mutual adjustment, late age at menarche, early age at menopause and duration of OC use showed similar risk reductions of 7-8% per year of menstrual life, whereas the decreased risk associated with cumulative duration of FTPs was stronger (22% per year). In conclusion, our findings confirmed a reduction in risk of endometrial cancer with factors associated with a lower cumulative exposure to estrogen and/or higher exposure to progesterone, such as increasing number of FTPs and shorter menstrual lifespan and, therefore, support an important role of hormonal mechanisms in endometrial carcinogenesis.

Occupational exposures contribute to educational inequalities in lung cancer incidence among men: Evidence from the EPIC prospective cohort study

The aim of this study is to investigate to what extent occupational exposures may explain socioeconomic inequalities in lung cancer incidence after adjusting for smoking and dietary factors. Analyses were based on a subsample of the European Prospective Investigation into Cancer and Nutrition (EPIC study), a prospective cohort. The analyses included 703 incident lung cancer cases among men in Denmark, the United Kingdom, Germany, Italy, Spain and Greece. The socioeconomic position was measured using the highest level of education. The estimates of relative indices of inequality (RII) were computed with Cox regression models. We first adjusted for smoking (with detailed information on duration and quantity) and dietary factors (fruits and vegetables consumption) and then for occupational exposures. The exposure to three carcinogens [asbestos, heavy metals and polycyclic aromatic hydrocarbons (PAH)] was analyzed. The occupational exposures explained 14% of the socioeconomic inequalities remaining after adjustment for smoking and fruits and vegetables consumption. The inequalities remained nevertheless statistically significant. The RII decreased from 1.87 (95% CI: 1.36-2.56) to 1.75 (1.27-2.41). The decrease was more pronounced when adjusting for asbestos than for heavy metals or PAH. Analyses by birth cohort suggested an effect of occupational exposures among older men, while due to small number of endpoints, no conclusion could be drawn about the role of occupational exposures in educational inequalities among younger men. Our study revealed that the impact of occupational exposures on socioeconomic inequalities in cancer incidence, rarely studied until now, exists while of modest magnitude.

A polygon-based locally-weighted-average method for smoothing disease rates of small units

BACKGROUND

Disease rates for geographic areas with small populations may be unstable. Therefore, accurate nonparametric methods for smoothing or stabilizing rates are needed.

METHODS

We propose an innovative locally-weighted-average method as an easy tool for disease surveillance. Our approach has several important advantages over existing locally-weighted-average methods. One advantage is that the buffer zone is created based on a polygon rather than centroid. Second, the buffer distance is determined by a user-specified population threshold. Third, a weighting factor that accounts for variability in the rate is used in the smoothing process. We further propose a variance-driven procedure to reduce arbitrariness in selecting the population threshold, and a binary search technique to quickly and precisely find the buffer distance according to the specified population threshold. Lastly, we develop a software tool using ArcObjects (ESRI, Redland, CA) to implement this method.

RESULTS

Our method was applied to town-level lung cancer incidence rates for New Hampshire. A comparison with a traditional point-based method indicated that our method produced less under- and over-smoothing.

CONCLUSION

Our method and the software tool are suitable for researchers and public health workers who want to apply geographic information systems to map smoothed disease rates for exploratory purposes.

Catechol-O-methyltransferase and breast cancer risk

Recent studies suggest that a polymorphism in catechol-O-methyltransferase (COMT) is associated with increased risk of breast cancer. Methylation by COMT is the principal pathway for inactivation of catechol estrogens, which are hypothesized to participate in estrogen-induced carcinogenesis. We examined the association of COMT genotype and breast cancer risk in a population-based, case-control study of invasive breast cancer in North Carolina. The study population consisted of 654 cases and 642 controls, with approximately equal numbers of African-American and white women and women under the age of 50 and aged 50 or over. Contrary to previous reports, we did not observe an association between one or more copies of the low activity COMT allele (COMT-L) and breast cancer risk. Multivariate relative risks (RRs) were 0.8 (95% confidence interval: 0.6-1.1) for COMT-HL and 0.8 (0.6-1.1) for COMT-LL, compared with the COMT-HH genotype. RRs for COMT did not differ among African-American and white women and we did not observe strong modification of RR estimates by menopausal status, body mass index, physical activity or other covariates. Our results suggest that COMT genotype is not related to breast cancer risk.

Intralesional cyclosporine for psoriasis. Relationship of dose, tissue levels, and efficacy

BACKGROUND AND DESIGN--To avoid systemic side effects, topical and intralesional administration of cyclosporine has been used; however, only intralesional administration has been successful. To understand more about the dosing requirements and resultant tissue levels of intralesional cyclosporine, we injected psoriasis plaques in a double-blind fashion with three different concentrations of cyclosporine (17 mg/mL in seven patients, 10 mg/mL in 13 patients, and 2.5 mg/mL in 11 patients) or matching vehicle three times weekly for 4 weeks. RESULTS--Statistically significant improvement was observed in plaques treated with 17 mg/mL (P = .003) compared with vehicle-treated plaques; the improvements in plaques treated with 10 mg/mL (P = .078) and 2.5 mg/mL (P = .054) achieved marginal statistical significance compared with vehicle treatment. Four weeks after discontinuation of therapy, the change from pretherapy in plaques that had received 17 mg/mL of cyclosporine was statistically significantly better (P less than .0001) than that with vehicle treatment. A similar finding but of marginal statistical significance (P = .059) occurred in the plaques that had received 10 mg/mL of cyclosporine. Throughout the study, untreated psoriasis plaques did not improve. Transient pain was the most common side effect noted with both cyclosporine and vehicle injections. Tissue levels of cyclosporine tended to be highest in plaques receiving the 17-mg/mL concentration; blood levels of cyclosporine were low throughout the study.

CONCLUSIONS

--Intralesional cyclosporine requires a sufficient dosage to improve psoriasis, apparently by a local mechanism of action. Improvement may persist for 4 weeks or longer.

Cyclosporine A metabolism by cytochrome P-450III occurs in microsomes from rat liver but not from normal epidermis or psoriatic lesions

Cyclosporine A is efficacious in the treatment of psoriasis when taken orally or injected intralesionally but not topically. Lack of penetration to necessary locations or rapid metabolism during passage through the epidermis may account for the ineffectiveness. Cytochromes P-450III in the liver are known to be involved in cyclosporine metabolism and inactivation. This study was undertaken to determine if an epidermal cytochrome P-450III exists that can inactivate topical cyclosporine A. Rats were treated with the macrolide antibiotic erythromycin to induce the cytochrome P-450III family of enzymes. Microsomal fractions were prepared from liver and epidermis of rats and from lesional areas of psoriasis patients. NADPH cytochrome C reductase activity was determined as a positive control for microsomal enzymatic activity. Formation of metabolite 1, the predominant metabolite of cyclosporine A, by liver microsomes was increased 193% after 10 d erythromycin treatment. The cytochrome P-450 dependent activity in microsomes from the epidermis of control and erythromycin-treated rats and in microsomes from psoriatic tissue was at the detection limits of the assay system. Cytochrome P-450III gene family mRNA were detectable by polymerase chain reaction in liver but not in psoriatic or normal epidermis. The lack of detectable P-450III mRNA and the absence or minimal conversion of cyclosporine A to inactive metabolites by epidermal microsomes suggest that the ineffectiveness of topical cyclosporine A in psoriasis may not be due to inactivation of cyclosporine A by cytochrome P-450 in the skin.

Mechanisms of cyclosporine A inhibition of antigen-presenting activity in uninvolved and lesional psoriatic epidermis

To elucidate how cyclosporine A affects antigen-presenting cell subsets and their function in human skin, we studied patients with psoriasis undergoing a therapeutic trial of cyclosporine A. Immunologic parameters abnormal in psoriatic epidermis were evaluated before and early in the course of therapy. We quantitated function and numbers of skin biopsy-derived epidermal cells with potential antigen-presenting cell (APC) activity. The antigen-presenting capacity of epidermal cells from normal-appearing skin to activate allogeneic T cells was profoundly inhibited (81% decrease) 7 d after the onset of therapy (p less than 0.05). Thus, cyclosporine A therapy inhibited T-cell activation mediated by Langerhans cells in uninvolved skin. By contrast, in lesional skin epidermal allo-antigen presenting activity was only partially inhibited at this early time point (55 +/- 7% decrease) (p less than 0.01, n = 8). The percentage decrease in allo-antigen-presenting cell activity correlated with reduced clinical activity of the lesions, r = 0.84. In three patients also examined at 14 d, we found an additional 42 +/- 5% decrease between day 7 and 14. Decreased allo-antigen-presenting activity in lesional skin was not associated with a decrease in the number of CD1+ Langerhans cells or epidermal cell release of detectable amounts of cyclosporine A or other soluble factors that abrogate T-cell alloreactivity. The time course and degree of inhibition of antigen-presenting capacity within involved psoriatic skin correlated best with a significant (p less than 0.01) reduction in non-Langerhans cell DR+ leukocytes (from 3.0 +/- 1.2% to 1.0 +/- 0.6% at day 7) (r = 0.71). Cyclosporine A therapy was associated with a rapid and complete loss of HLe1-DR+ keratinocytes (94% decrease at 7 d) in lesional skin despite the skin still being quite involved with psoriasis at this point and antigen-presenting cell activity being only 60% reduced. In conclusion, cyclosporine A interferes with T-cell activation by human epidermis through at least two mechanisms: 1) in uninvolved skin, rapid inhibition of Langerhans cell-mediated activation of T cells, and 2) in lesional skin, delayed inhibition of antigen-presenting activity which appears to correlate with the time course and level of reductions in non-Langerhans cell DR+ leukocytes. The antigen-presenting activity of the latter cells appears to be cyclosporine A resistant. In psoriatic lesions, early and complete loss of DR expression on lesional keratinocytes during cyclosporine A therapy is likely due to decreased lesional T-cell lymphokine production critical for keratinocyte DR expression.(ABSTRACT TRUNCATED AT 400 WORDS)

Proliferative epidermis of essential fatty acid deficient mice has reduced cyclic AMP content

We have simultaneously measured epidermal DNA synthesis, epidermal thickness and cyclic nucleotide levels in essential fatty acid (EFA) deficient hairless mice skin. In vitro epidermal DNA synthesis and epidermal thickness were significantly increased in EFA deficient epidermis. Cyclic AMP levels were significantly reduced when expressed using three different data bases. Cyclic GMP levels were increased using two data bases but these increases were not statistically significant; Cyclic AMP/cyclic GMP ratios were significantly decreased in the EFA deficient skin. The results provide evidence that cyclic nucleotide levels are altered in an animal model of benign epidermal proliferation.