Reproductive factors and gall-bladder cancer, and the effect of common genetic variants on these associations: a case-control study in India.

BACKGROUND: In India, as elsewhere, the incidence of gall-bladder cancer (GBC) is substantially higher in women than in men. Yet, the relevance of reproductive factors to GBC remains poorly understood. METHODS: We used logistic regression adjusted for age, education and area to examine associations between reproductive factors and GBC risk, using 790 cases of histologically confirmed GBC and group-matched 1726 visitor controls. We tested the interaction of these associations by genetic variants known to increase the risk of GBC. RESULTS: Parity was strongly positively associated with GBC risk: each additional pregnancy was associated with an ∼25% higher risk {odds ratio [OR] 1.26 [95% confidence interval (95% CI) 1.17-1.37]}. After controlling for parity, GBC risk was weakly positively associated with later age of menarche [postmenopausal women, OR 1.11 (95% CI 1.00-1.22) per year], earlier menopause [OR 1.03 (95% CI 1.00-1.06) per year] and shorter reproductive lifespan [OR 1.04 (95% CI 1.01-1.07) per year], but there was little evidence of an association with breastfeeding duration or years since last pregnancy. Risk alleles of single-nucleotide polymorphisms in the ABCB4 and ABCB1 genetic regions had a multiplicative effect on the association with parity, but did not interact with other reproductive factors. CONCLUSIONS: We observed higher GBC risk with higher parity and shorter reproductive lifespan, suggesting an important role for reproductive and hormonal factors.

The International Collaboration for Research methods Development in Oncology (CReDO) workshops: shaping the future of global oncology research.

Low-income and middle-income countries (LMICs) have a disproportionately high burden of cancer and cancer mortality. The unique barriers to optimum cancer care in these regions necessitate context-specific research. The conduct of research in LMICs has several challenges, not least of which is a paucity of formal training in research methods. Building capacity by training early career researchers is essential to improve research output and cancer outcomes in LMICs. The International Collaboration for Research methods Development in Oncology (CReDO) workshop is an initiative by the Tata Memorial Centre and the National Cancer Grid of India to address gaps in research training and increase capacity in oncology research. Since 2015, there have been five CReDO workshops, which have trained more than 250 oncologists from India and other countries in clinical research methods and protocol development. Participants from all oncology and allied fields were represented at these workshops. Protocols developed included clinical trials, comparative effectiveness studies, health services research, and observational studies, and many of these protocols were particularly relevant to cancer management in LMICs. A follow-up of these participants in 2020 elicited an 88% response rate and showed that 42% of participants had made progress with their CReDO protocols, and 73% had initiated other research protocols and published papers. In this Policy Review, we describe the challenges to research in LMICs, as well as the evolution, structure, and impact of CReDO and other similar workshops on global oncology research.

The Role of Gallstones in Gallbladder Cancer in India: A Mendelian Randomization Study.

BACKGROUND: Past history of gallstones is associated with increased risk of gallbladder cancer in observational studies. We conducted complementary observational and Mendelian randomization (MR) analyses to determine whether history of gallstones is causally related to development of gallbladder cancer in an Indian population. METHODS: To investigate associations between history of gallstones and gallbladder cancer, we used questionnaire and imaging data from a gallbladder cancer case-control study conducted at Tata Memorial Hospital, Mumbai, Maharashtra, India (cases = 1,170; controls = 2,525). We then used 26 genetic variants identified in a genome-wide association study of 27,174 gallstone cases and 736,838 controls of European ancestry in an MR approach to assess causality. The association of these genetic variants with both gallstones and gallbladder cancer was examined in the gallbladder cancer case-control study. Various complementary MR approaches were used to evaluate the robustness of our results in the presence of pleiotropy and heterogeneity, and to consider the suitability of the selected SNPs as genetic instruments for gallstones in an Indian population. RESULTS: We found a strong observational association between gallstones and gallbladder cancer using self-reported history of gallstones [OR = 4.5; 95% confidence interval (CI) = 3.5-5.8] and with objective measures of gallstone presence using imaging techniques (OR = 2.0; 95% CI = 1.5-2.7). We found consistent causal estimates across all MR techniques, with ORs for gallbladder cancer in the range of 1.3-1.6. CONCLUSIONS: Our findings indicate a causal relationship between history of gallstones and increased risk of gallbladder cancer, albeit of a smaller magnitude than those found in observational analysis. IMPACT: Our findings emphasize the importance of gallstone treatment for preventing gallbladder cancer in high-risk individuals.

Mustard oil consumption, cooking method, diet and gallbladder cancer risk in high- and low-risk regions of India.

The current study aimed to investigate the role of cooking with mustard oil and other dietary factors in relation to gallbladder cancer (GBC) in high- and low-incidence regions of India. A case-control study was conducted including 1,170 histologically confirmed cases and 2,525 group-matched visitor controls from the largest cancer hospital in India. Dietary data were collected through a food frequency questionnaire. For oil consumption, we enquired about monthly consumption of 11 different types of cooking oil per family and the number of individuals usually sharing the meal to estimate per-individual consumption of oil. Information about method of cooking was also requested. Odds ratios (ORs) and 95% confidence intervals (CIs) quantifying the association of GBC risk consumption of different types of oil, method of cooking, and dietary food items, were estimated using logistic regression models, after adjusting for potential confounders. High consumption of mustard oil was associated with GBC risk in both high- and low-risk regions (OR = 1.33, 95% CI = 0.99-1.78; OR = 3.01, 95% CI = 1.66-5.45), respectively. An increased risk of GBC was observed with deep frying of fresh fish in mustard oil (OR = 1.57, 95% CI = 0.99-2.47, p-value = 0.052). A protective association was observed with consumption of leafy vegetables, fruits, onion and garlic. No association was observed between consumption of meat, spicy food, turmeric, pulses or with any other oil as a cooking medium. The effect of high consumption of mustard oil on GBC risk, if confirmed, has implications for the primary prevention of GBC, via a reduced consumption.

Association between coffee drinking and telomere length in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

Mounting evidence indicates that coffee, a commonly consumed beverage worldwide, is inversely associated with various chronic diseases and overall mortality. Few studies have evaluated the effect of coffee drinking on telomere length, a biomarker of chromosomal integrity, and results have been inconsistent. Understanding this association may provide mechanistic insight into associations of coffee with health. The aim of our study was to test the hypothesis that heavier coffee intake is associated with greater likelihood of having above-median telomere length. We evaluated the cross-sectional association between coffee intake and relative telomere length using data from 1,638 controls from four previously conducted case-control studies nested in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Coffee intake was assessed using a food frequency questionnaire, and relative telomere length was measured from buffy-coat, blood, or buccal cells. We used unconditional logistic regression models to generate multivariable-adjusted, study-specific odds ratios for the association between coffee intake and relative telomere length. We then conducted a random-effects meta-analysis to determine summary odds ratios. We found that neither summary continuous (OR = 1.01, 95% CI = 0.99-1.03) nor categorical (OR <3 cups/day vs. none = 1.37, 95% CI = 0.71-2.65; OR ≥3 cups/day vs. none = 1.47, 95% CI = 0.81-2.66) odds ratio estimates of coffee drinking and relative telomere length were statistically significant. However, in the largest of the four contributing studies, moderate (<3 cups/day) and heavy coffee drinkers (≥3 cups/day) were 2.10 times (95% CI = 1.25, 3.54) and 1.93 times as likely (95% CI = 1.17, 3.18) as nondrinkers to have above-median telomere length, respectively. In conclusion, we found no evidence that coffee drinking is associated with telomere length. Thus, it is unlikely that telomere length plays a role in potential coffee-disease associations.

Lack of association between modifiable exposures and glioma risk: a Mendelian randomization analysis.

BACKGROUND: The etiological basis of glioma is poorly understood. We have used genetic markers in a Mendelian randomization (MR) framework to examine if lifestyle, cardiometabolic, and inflammatory factors influence the risk of glioma. This methodology reduces bias from confounding and is not affected by reverse causation. METHODS: We identified genetic instruments for 37 potentially modifiable risk factors and evaluated their association with glioma risk using data from a genome-wide association study of 12 488 glioma patients and 18 169 controls. We used the estimated odds ratio of glioma associated with each of the genetically defined traits to infer evidence for a causal relationship with the following exposures:Lifestyle and dietary factors-height, plasma insulin-like growth factor 1, blood carnitine, blood methionine, blood selenium, blood zinc, circulating adiponectin, circulating carotenoids, iron status, serum calcium, vitamins (A1, B12, B6, E, and 25-hydroxyvitamin D), fatty acid levels (monounsaturated, omega-3, and omega-6) and circulating fetuin-A;Cardiometabolic factors-birth weight, high density lipoprotein cholesterol, low density lipoprotein cholesterol, total cholesterol, total triglycerides, basal metabolic rate, body fat percentage, body mass index, fasting glucose, fasting proinsulin, glycated hemoglobin levels, diastolic and systolic blood pressure, waist circumference, waist-to-hip ratio; andInflammatory factors- C-reactive protein, plasma interleukin-6 receptor subunit alpha and serum immunoglobulin E. RESULTS: After correction for the testing of multiple potential risk factors and excluding associations driven by one single nucleotide polymorphism, no significant association with glioma risk was observed (ie, PCorrected > 0.05). CONCLUSIONS: This study did not provide evidence supporting any of the 37 factors examined as having a significant influence on glioma risk.

Current status of human papillomavirus vaccination in India's cervical cancer prevention efforts.

Efforts are being made to scale up human papillomavirus (HPV) vaccination for adolescent girls in India. Bivalent and quadrivalent HPV vaccines were licensed in the country in 2008, and a nonavalent vaccine was licensed in 2018. Demonstration projects initiated in Andhra Pradesh and Gujarat in 2009 introduced HPV vaccination in public health services in India. Following a few deaths in these projects, although subsequently deemed unrelated to vaccination, HPV vaccination in research projects was suspended. This suspension by default resulted in some participants in a trial evaluating two versus three doses receiving only one dose. Since 2016, the successful introduction of HPV vaccination in immunisation programmes in Punjab and Sikkim (with high coverage and safety), government-sponsored opportunistic vaccination in Delhi, prospects of a single dose providing protection, and future availability of an affordable Indian vaccine shows promise for future widespread implementation and evaluation of HPV vaccination in India.

Radiation-Related Risk of Cancers of the Upper Digestive Tract among Japanese Atomic Bomb Survivors.

As a follow-up to the comprehensive work on solid cancer incidence in the Life Span Study (LSS) cohort of atomic bomb survivors between 1958 and 1998, we report here on updated radiation risk estimates for upper digestive tract cancers. In this study, we added 11 years of follow-up (1958-2009), used improved radiation dose estimates, considered effects of smoking and alcohol consumption and performed dose-response analyses by anatomical sub-site. In examining 52 years'worth of data, we ascertained the occurrence of 394 oral cavity/pharyngeal cancers, 486 esophageal cancers and 5,661 stomach cancers among 105,444 subjects. The radiation risk for oral cavity/pharyngeal cancer, other than salivary gland, was elevated but not significantly so. In contrast, salivary gland cancer exhibited a strong linear dose response with excess relative risk (ERR) of 2.54 per Gy [95% confidence interval (CI): 0.69 to 6.1]. Radiation risk decreased considerably with increasing age at time of exposure (-66% per decade, 95% CI: -88% to -32%). The dose response for esophageal cancer was statistically significant under a simple linear, linear-quadratic and quadratic model. Both linear-quadratic and quadratic models described the data better than a simple linear model and, of the two, the quadratic model showed a marginally better fit based on the Akaike Information Criteria. Sex difference in linear ERRs was not statistically significant; however, when the dose-response shape was allowed to vary by sex, statistically significant curvature was found among males, with no evidence of quadratic departure from linearity among females. The risk for stomach cancer increased significantly with dose and there was little evidence for quadratic departure from linearity among either males or females. The sex-averaged ERR at age 70 was 0.33 per Gy (95% CI: 0.20 to 0.47). The ERR decreased significantly (-1.93 power of attained age, 95% CI: -2.94 to -0.82) with increasing attained age, but not with age at exposure, and was higher in females than males (P = 0.02). Our results are largely consistent with the results of prior LSS analyses. Salivary gland, esophageal and stomach cancers continue to show significant increases in risk with radiation dose. Adjustment for lifestyle factors had almost no impact on the radiation effect estimates. Further follow-up of the LSS cohort is important to clarify the nature of radiation effects for upper digestive tract cancers, especially for oral cavity/pharyngeal and esophageal cancers, for which detailed investigation for dose-response shape could not be conducted due to the small number of cases.

Publisher Correction: Mendelian randomisation study of the relationship between vitamin D and risk of glioma.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Transcriptome-Wide Association Study Identifies New Candidate Susceptibility Genes for Glioma.

Genome-wide association studies (GWAS) have so far identified 25 loci associated with glioma risk, with most showing specificity for either glioblastoma (GBM) or non-GBM tumors. The majority of these GWAS susceptibility variants reside in noncoding regions and the causal genes underlying the associations are largely unknown. Here we performed a transcriptome-wide association study to search for novel risk loci and candidate causal genes at known GWAS loci using Genotype-Tissue Expression Project (GTEx) data to predict cis-predicted gene expression in relation to GBM and non-GBM risk in conjunction with GWAS summary statistics on 12,488 glioma cases (6,183 GBM and 5,820 non-GBM) and 18,169 controls. Imposing a Bonferroni-corrected significance level of P < 5.69 × 10-6, we identified 31 genes, including GALNT6 at 12q13.33, as a candidate novel risk locus for GBM (mean Z = 4.43; P = 5.68 × 10-6). GALNT6 resides at least 55 Mb away from any previously identified glioma risk variant, while all other 30 significantly associated genes were located within 1 Mb of known GWAS-identified loci and were not significant after conditioning on the known GWAS-identified variants. These data identify a novel locus (GALNT6 at 12q13.33) and 30 genes at 12 known glioma risk loci associated with glioma risk, providing further insights into glioma tumorigenesis. SIGNIFICANCE: This study identifies new genes associated with glioma risk, increasing understanding of how these tumors develop.

Sex-specific gene and pathway modeling of inherited glioma risk.

Background: To date, genome-wide association studies (GWAS) have identified 25 risk variants for glioma, explaining 30% of heritable risk. Most histologies occur with significantly higher incidence in males, and this difference is not explained by currently known risk factors. A previous GWAS identified sex-specific glioma risk variants, and this analysis aims to further elucidate risk variation by sex using gene- and pathway-based approaches. Methods: Results from the Glioma International Case-Control Study were used as a testing set, and results from 3 GWAS were combined via meta-analysis and used as a validation set. Using summary statistics for nominally significant autosomal SNPs (P < 0.01 in a previous meta-analysis) and nominally significant X-chromosome SNPs (P < 0.01), 3 algorithms (Pascal, BimBam, and GATES) were used to generate gene scores, and Pascal was used to generate pathway scores. Results were considered statistically significant in the discovery set when P < 3.3 × 10-6 and in the validation set when P < 0.001 in 2 of 3 algorithms. Results: Twenty-five genes within 5 regions and 19 genes within 6 regions reached statistical significance in at least 2 of 3 algorithms in males and females, respectively. EGFR was significantly associated with all glioma and glioblastoma in males only and a female-specific association in TERT, all of which remained nominally significant after conditioning on known risk loci. There were nominal associations with the BioCarta telomeres pathway in both males and females. Conclusions: These results provide additional evidence that there may be differences by sex in genetic risk for glioma. Additional analyses may further elucidate the biological processes through which this risk is conferred.

Genetic landscape of gallbladder cancer: Global overview.

Gallbladder cancer (GBC) is a rare malignancy of biliary tract cancer (BTC), characterized by late presentation and poor prognosis. It exhibits wide geographical as well as ethnical variations. So, diverse epidemiology along with etiological factors have been discussed in the current article. Present review unravels the germ line polymorphisms contributing to GBC susceptibility through candidate gene approach and GWAS. GBC is enriched with multiple mutations consisting of both passenger and driver mutations. The identification of the hotspot driver mutations which are involved in the etiopathogenesis of this cancer is necessary, before targeted therapies could be implemented clinically. Thus, this review sheds lights on both traditional low throughput methods along with high throughput NGS used to determine somatic mutations in cancer. With the advent of GWAS and high throughput sequencing methods, it is possible to comprehend the mutational landscape of this enigmatic disease. This article is the first one to provide insights into the genetic heterogeneity of GBC along with somatic mutational data from Catalogue of Somatic Mutations in Cancer (COSMIC) database. In addition, management of tumor heterogeneity as a therapeutic challenge has been discussed. Future goals involve liquid biopsy based research for better clinical management of the disease. Therefore, research efforts involving discovery of non- invasive markers for early stage cancer detection along with novel therapies should be directed.

India-United States Dialogue on Traditional Medicine: Toward Collaborative Research and Generation of an Evidence Base.

Therapies originating from traditional medical systems are widely used by patients in both India and the United States. The first India-US Workshop on Traditional Medicine was held in New Delhi, India, on March 3 and 4, 2016, as a collaboration between the Ministry of Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homoeopathy (AYUSH) of the Government of India, the US National Cancer Institute (NCI), National Institutes of Health, and the Office of Global Affairs, US Department of Health and Human Services. It was attended by Indian and US policymakers, scientists, academics, and medical practitioners from various disciplines. The workshop provided an opportunity to open a dialogue between AYUSH and NCI to identify promising research results and potential topics for Indo-US collaboration. Recommendations that emerged from the workshop underlined the importance of applying rational and scientific approaches for drug development; standardizing traditional medicine products and procedures to ensure reliability and reproducibility; promotion of collaboration between Indian traditional medicine practitioners and researchers and US researchers; greater integration of evidence-based traditional medicine practices with mainstream medical practices in India; and development of training programs between AYUSH and NCI to facilitate crosstraining. Several positive developments took place after the thought-provoking deliberations.

Age-specific genome-wide association study in glioblastoma identifies increased proportion of 'lower grade glioma'-like features associated with younger age.

Glioblastoma (GBM) is the most common malignant brain tumor in the United States. Incidence of GBM increases with age, and younger age-at-diagnosis is significantly associated with improved prognosis. While the relationship between candidate GBM risk SNPs and age-at-diagnosis has been explored, genome-wide association studies (GWAS) have not previously been stratified by age. Potential age-specific genetic effects were assessed in autosomal SNPs for GBM patients using data from four previous GWAS. Using age distribution tertiles (18-53, 54-64, 65+) datasets were analyzed using age-stratified logistic regression to generate p values, odds ratios (OR), and 95% confidence intervals (95%CI), and then combined using meta-analysis. There were 4,512 total GBM cases, and 10,582 controls used for analysis. Significant associations were detected at two previously identified SNPs in 7p11.2 (rs723527 [p54-63 = 1.50x10-9 , OR54-63 = 1.28, 95%CI54-63 = 1.18-1.39; p64+ = 2.14x10-11 , OR64+ = 1.32, 95%CI64+ = 1.21-1.43] and rs11979158 [p54-63 = 6.13x10-8 , OR54-63 = 1.35, 95%CI54-63 = 1.21-1.50; p64+ = 2.18x10-10 , OR64+ = 1.42, 95%CI64+ = 1.27-1.58]) but only in persons >54. There was also a significant association at the previously identified lower grade glioma (LGG) risk locus at 8q24.21 (rs55705857) in persons ages 18-53 (p18-53 = 9.30 × 10-11 , OR18-53 = 1.76, 95%CI18-53 = 1.49-2.10). Within The Cancer Genome Atlas (TCGA) there was higher prevalence of 'LGG'-like tumor characteristics in GBM samples in those 18-53, with IDH1/2 mutation frequency of 15%, as compared to 2.1% [54-63] and 0.8% [64+] (p = 0.0005). Age-specific differences in cancer susceptibility can provide important clues to etiology. The association of a SNP known to confer risk for IDH1/2 mutant glioma and higher prevalence of IDH1/2 mutation within younger individuals 18-53 suggests that more younger individuals may present initially with 'secondary glioblastoma.'

Considerations on the use of the terms radiosensitivity and radiosusceptibility.

The separate use of the terms 'radiosensitivity' and 'radiosusceptibility' has been suggested to describe variability in the risk of, respectively, adverse tissue reactions (deterministic effect) following radiotherapy and radiation-induced cancer (stochastic effect). The aim of this note is to present arguments against such distinction. We feel that it is premature to make a concrete final judgement on these definitions because of the limited understanding of the mechanisms underlying individual sensitivity to both radiation-related cancers and radiation-related tissue injury. Moreover, the exclusive application of 'radiosensitivity' in relation to deterministic effects and the term 'radiosusceptibility' in relation to cancer carries the risk of being wrongly interpreted as evidence for a high, genetically driven sensitivity to radiation in all patients who develop adverse tissue reactions and a high genetic susceptibility to cancer in those who develop radiation-induced malignancies. There is a need for further research to better define these phenomena and their interrelationships.

Sex-specific glioma genome-wide association study identifies new risk locus at 3p21.31 in females, and finds sex-differences in risk at 8q24.21.

Incidence of glioma is approximately 50% higher in males. Previous analyses have examined exposures related to sex hormones in women as potential protective factors for these tumors, with inconsistent results. Previous glioma genome-wide association studies (GWAS) have not stratified by sex. Potential sex-specific genetic effects were assessed in autosomal SNPs and sex chromosome variants for all glioma, GBM and non-GBM patients using data from four previous glioma GWAS. Datasets were analyzed using sex-stratified logistic regression models and combined using meta-analysis. There were 4,831 male cases, 5,216 male controls, 3,206 female cases and 5,470 female controls. A significant association was detected at rs11979158 (7p11.2) in males only. Association at rs55705857 (8q24.21) was stronger in females than in males. A large region on 3p21.31 was identified with significant association in females only. The identified differences in effect of risk variants do not fully explain the observed incidence difference in glioma by sex.