Exclusive use of different types of tobacco products, exposure to secondhand tobacco smoke and risk of subtypes of head and neck cancer among Indian males.

Tobacco products are used in vary many forms in India. Although the risk of tobacco uses in developing head and neck cancer (HNC) is known, risk by exclusive use of different tobacco products on HNC and its subtypes is poorly understood. A case-control study was conducted at a tertiary cancer hospital, which receives cases from different geographical regions of India with use of different types of tobacco products. The study included 824 oral cavity (OC), 149 oropharynx (OPX) 104 hypopharyngeal (HPX) and 81 larynx (LX) cancer cases and 1206 visitor controls. Information on 11 different types of tobacco products and exposure to secondhand smoke was collected through structured questionnaires. Odds ratios (OR) and 95% confidence intervals (CI), for the association of various HNC subtypes with exclusive use of each tobacco product compared to nonusers of tobacco were estimated using logistic regression models, after adjusting for potential confounders. Exclusive use of any type of smokeless tobacco product was strongly associated with all subtypes of HNC. Gutka chewing (only) had highest risk (OR = 33.67; 95% CI = 19.8-57.0) while exclusive users of betel quid with tobacco (BQ + T), tobacco quid, Khaini, Mawa and Mishri users had a OR of 14.77, 24.20, 5.33, 2.96 and 3.32, respectively, for development of OC. Bidi smoking and secondhand smoke was independently associated with increased risk of HNC. Our study indicates that tobacco control policies should focus on product specific awareness messaging that switching between tobacco product types is not a safe alternative to complete cessation.

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.

Common genetic variation and risk of gallbladder cancer in India: a case-control genome-wide association study.

BACKGROUND: Gallbladder cancer is highly lethal, with notable differences in incidence by geography and ethnic background. The aim of this study was to identify common genetic susceptibility alleles for gallbladder cancer. METHODS: In this case-control genome-wide association study (GWAS), we did a genome-wide scan of gallbladder cancer cases and hospital visitor controls, both of Indian descent, followed by imputation across the genome. Cases were patients aged 20-80 years with microscopically confirmed primary gallbladder cancer diagnosed or treated at Tata Memorial Hospital, Mumbai, India, and enrolled in the study between Sept 12, 2010, and June 8, 2015. We only included patients who had been diagnosed less than 1 year before the date of enrolment and excluded patients with any other malignancies. We recruited visitor controls aged 20-80 years with no history of cancer visiting all departments or units of Tata Memorial Hospital during the same time period and frequency matched them to cases on the basis of age, sex, and current region of residence. We estimated association using logistic regression, adjusting for age, sex, and five eigenvectors. We recruited samples for a replication cohort from patients visiting Tata Memorial Hospital between Aug 4, 2015, and May 17, 2016, and patients visiting the Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India, between July, 2010, and May, 2015. We used the same inclusion and exclusion criteria for the replication set. We examined three of the most significant single-nucleotide polymorphisms (SNPs) in the replication cohort and did a meta-analysis of the GWAS discovery and replication sets to get combined estimates of association. FINDINGS: The discovery cohort comprised 1042 gallbladder cancer cases and 1709 controls and the replication cohort contained 428 gallbladder cancer cases and 420 controls. We observed genome-wide significant associations for several markers in the chromosomal region 7q21.12 harbouring both the ABCB1 and ABCB4 genes, with the most notable SNPs after replication and meta-analysis being rs1558375 (GWAS p=3·8 × 10-9; replication p=0·01; combined p=2·3 × 10-10); rs17209837 (GWAS p=2·0 × 10-8; replication p=0·02; combined p=2·3 × 10-9), and rs4148808 (GWAS p=2·4 × 10-8; replication p=0·008; combined p=2·7 × 10-9). Combined estimates of per-allele trend odds ratios were 1·47 (95% CI 1·30-1·66; p=2·31 × 10-10) for rs1558375, 1·61 (1·38-1·89; p=2·26 × 10-9) for rs17209837, and 1·57 (1·35-1·82; p=2·71 × 10-9) for rs4148808. GWAS heritability analysis suggested that common variants are associated with substantial variation in risk of gallbladder cancer (sibling relative risk 3·15 [95% CI 1·80-5·49]). INTERPRETATION: To our knowledge, this study is the first report of common genetic variation conferring gallbladder cancer risk at genome-wide significance. This finding, along with in-silico and biological evidence indicating the potential functional significance of ABCB1 and ABCB4, underlines the likely importance of these hepatobiliary phospholipid transporter genes in the pathology of gallbladder cancer. FUNDING: The Tata Memorial Centre and Department of Biotechnology.

Understanding rural-urban differences in risk factors for breast cancer in an Indian population.

PURPOSE: Although cancer registry data indicate that there are large differences in breast cancer (BC) rates between rural and urban regions of India, the reasons for these differences are not well understood. METHODS: We conducted a hospital based case-control study (1,637 breast cancer cases; 1,515 visitor controls) in Mumbai, India, during the years 2009-2013. Extensive questionnaire data, anthropometry measurement and blood samples were collected on all participants. Using logistic regression models, we estimated risk based on odds ratio (OR) and 95 % confidence intervals (CI) for various reproductive and anthropometric measures, stratified by rural-urban status depending upon residence in first 20 years of life. RESULTS: Waist-to-hip ratio of ≥0.95 compared to ratio ≤0.84 was strongly associated with risk of BC in both rural and urban populations (ORurban = 4.10, 95 % CI 3.03-5.56; ORrural = 3.01, 95 % CI 1.85-4.90). First full-term pregnancy after the age of 25 compared to first full-term pregnancy below 20 years of age was associated with risk of BC in both urban and rural women (ORurban = 1.78, 95 % CI 1.32-2.41; ORrural = 2.24, 95 % CI 1.13-4.43). The prevalence of age at first full-term pregnancy was significantly lower in rural (mean age at first full-term pregnancy = 19.39 years) versus urban women (mean age at first full-term pregnancy = 22.62 years), whereas mean waist circumference was much higher in urban women (82.13 cm) compared to rural women (79.26 cm). We did not observe any association between breast feeding and risk of BC. CONCLUSIONS: Differences in the prevalence of central adiposity and age at first full-term pregnancy between rural and urban women from India may explain some differences in breast cancer rates between these two populations.

The Mutographs biorepository: A unique genomic resource to study cancer around the world.

Large-scale biorepositories and databases are essential to generate equitable, effective, and sustainable advances in cancer prevention, early detection, cancer therapy, cancer care, and surveillance. The Mutographs project has created a large genomic dataset and biorepository of over 7,800 cancer cases from 30 countries across five continents with extensive demographic, lifestyle, environmental, and clinical information. Whole-genome sequencing is being finalized for over 4,000 cases, with the primary goal of understanding the causes of cancer at eight anatomic sites. Genomic, exposure, and clinical data will be publicly available through the International Cancer Genome Consortium Accelerating Research in Genomic Oncology platform. The Mutographs sample and metadata biorepository constitutes a legacy resource for new projects and collaborations aiming to increase our current research efforts in cancer genomic epidemiology globally.

Risk factors for the development of triple-negative breast cancer versus non-triple-negative breast cancer: a case-control study.

The risk factors for breast cancer have been defined in several studies but there is deficient data for specific subtypes. We report here the pathological characteristics of a breast cancer cohort and risk factors for patients with triple-negative disease. In this case-control study, a prospective breast cancer cohort was evaluated for demographic, reproductive, obesity-related and other risk factors using a validated questionnaire. Tumors were characterized for routine pathological characteristics and immunohistochemical markers of basal-like breast cancer. Patients with triple-negative breast cancer (TNBC) constituted cases and those with non-TNBC were controls. Odds ratios (OR) were calculated for each risk factor and independent associations were tested in an unconditional logistic regression analysis. Between 2011 and 2014, 1146 patients were recruited, of whom 912 [TNBC 266 (29.1%), non-TNBC 646 (70.9%)] with sufficient pathology material were analysed. Reproductive factors of parity, breastfeeding, age-at-menarche, age at first full-term pregnancy and oral contraceptive use were not significantly associated with TNBC. Higher body mass index (BMI > 24.9 vs ≤ 24.9, OR 0.89, 95%CI 0.63-1.24, p = 0.49) was not significantly associated while lesser waist circumference (> 80 cm vs ≤ 80 cm, OR 0.64, 95%CI 0.45-0.9, p = 0.012) and lower waist-to-hip ratio were significantly associated (> 0.85 vs ≤ 0.85, OR 0.72, 95%CI 0.51-1.0, p = 0.056), with TNBC. History of tobacco use was not significantly associated while lower socio-economic status was borderline associated with TNBC (socio-economic category > 5 versus ≤ 5, OR 0.73, 95%CI 0.50-1.06, p = 0.106). No factor was significant after adjustment for covariates. Central obesity seems to be preferentially associated with non-TNBC, and lower socio-economic status with TNBC in India, while most other conventional risk factors of breast cancer show no significant association with TNBC versus non-TNBC.

Prevalence of human papillomavirus types in head and neck cancer sub-sites in the Indian population.

Although a subset of head and neck cancers (HNC) has been associated worldwide with mucosal high-risk human papillomaviruses (HPV), information on the prevalence of HPV-positive HNC in India is limited. In this study, we examined the prevalence of 21 subtypes of HPV in sub-sites of HNC (n = 175) in the western region of India. Type-specific multiplex genotyping assay was conducted at the Centre for Cancer Epidemiology, Tata Memorial Centre, to determine the prevalence of HPV subtypes. The HPV prevalence was observed to be 28.43%, 41.67%, 38.89% and 15.79% in the oral cavity, oropharynx, hypopharynx and larynx tumour tissues, respectively. The HPV 16 genotype was most common in all HNC tumour tissues (30.29%), followed by HPV 58 (0.57%).

Cross-Sectional and Longitudinal Mental Health Status Prevailing among COVID-19 Patients in Mumbai, India.

Introduction: The aim was to determine the prevalence and predictors of depression among less symptomatic COVID-19 patients. Methods: A questionnaire-based assessment was conducted among asymptomatic or mildly symptomatic COVID-19 patients when admitted in a COVID-19 facility (T1) and after 6 months (T2). Interviews were conducted using the Patient Health Questionnaire-9 instrument. Socio-demographic details and length of facility stay were recorded. Changes in scores between the two-time points T1 and T2 were compared. Factors predicting depression were determined using Chi-square and Mann-Whitney U test during facility stay, and those predicting worsening over time were obtained using multivariate regression models. Results: Among the 91.4% (n = 450) participants, prevalence of depression was 38.4% (95% confidence interval [CI] = 34.0-43.0) with a significant increase of 7.8-fold (95% CI = 4.8-12.8) in depression as the duration of stay increased beyond a median of 5 days. A significant association was observed between higher income and lower depression (odds ratios = 0.6, P = 0.03). 84% (n = 378) responded at the second timepoint assessment after a median of 6.62 months (T2). There was a significant difference observed between the 2.6% (n = 6) that worsened into depression at T2 and the 73.8% (n = 107) that improved out of depression at T2 (P ≤ 0.001). Age >45 years (P = 0.007), males (P = 0.011) and reinfection (P = 0.039) significantly led to worsening of depression. Conclusion: There is a need for actively detecting and managing depression in institutionally quarantined survivors, considering limiting such quarantine to no more than a week, and providing routine screening and care for depression beyond this period.

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 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.

Clinical course and outcome of patients with COVID-19 in Mumbai City: an observational study.

OBJECTIVE: To understand the outcome of hospitalised patients from Mumbai City, which had the highest number of COVID-19 cases in India. DESIGN: Observational study with follow-up. SETTING: Data extraction from medical records of patients with COVID-19 admitted to Nair Hospital & TN Medical College, Mumbai, India. PARTICIPANTS: 689 patients with COVID-19 were admitted in the hospital from 26 March 2020 to 11 May 2020. PRIMARY AND SECONDARY OUTCOME MEASURES: In-hospital mortality; joint effect of comorbidity and age on the risk of dying. RESULTS: A total of 689 patients (median age 44 years) admitted with RT-PCR-confirmed COVID-19 were included in the study. Of these, 77.36% of patients were discharged alive while 22.64% died. 11.61% required some kind of oxygen support while 2.8% of patients required intensive care unit admissions. Older age (HR 2.88, 95% CI 2.09 to 3.98), presence of comorbidities (HR 2.56, 95% CI 1.84 to 3.55), history of hypertension (HR 3.19, 95% CI 1.67 to 6.08), and presence of symptoms at the time of admission (HR 3.21, 95% CI 1.41 to 7.26) were associated with increased risk of in-hospital mortality. Treatment with a combination of azithromycin with hydroxychloroquine, antiviral or steroid compared with no treatment did not alter the disease course and in-hospital mortality. The combined effect of old age and presence of comorbid conditions was more pronounced in women than men. CONCLUSIONS: In-hospital patients were younger, less symptomatic with lesser need of ventilators and oxygen support as compared with many western countries. TRIAL REGISTRATION: Not applicable (observational study, not a clinical trial).

Utility of dried blood spots in detecting helicobacter pylori infection.

Purpose: Identifying infectious pathogens by collecting intravenous blood (IVB) is a well-established procedure, however, the collection of IVB in field epidemiological study is challenging. The dried blood spot (DBS) as an alternative to IVB has been introduced, although, there is a limited study to demonstrate the utility of DBS stored at various storage conditions and transported at different periods. This is an observational study, which evaluates the effectiveness of DBS in field epidemiological studies to identify infectious pathogens. Materials and Methods: A total of 264 paired DBS samples prepared from IVB, stored at 4°C, -20°C after period 24, 48 and 72 h. Serologically, enzyme-linked immunosorbent assay [ELISA] IgG antibody detected against Helicobacter pylori infection from DBS and compared with IVB. Results: Quantitatively, IgG antibody reactivity showed >87% correlation between IVB and DBS samples stored at 4°C or -20°C within 48 h of transport duration. DBS stored at 4°C shows, equal sensitivity 87.5% and specificity 95% before 48 h of transport duration, while at -20°C storage similar sensitivity 87.5% observed but slightly less specificity 86.36% observed as compared to 24 h of transport duration. One-way analysis of variance showed, nonsignificant difference at both (-20°C and 4°C) the stored condition with P value (P > 0.851) and (P > 0.477). Kappa values showed good inter-rater reliability between DBS and IVB in a range (0.77-0.81). Conclusion: No significant difference was observed in detecting H. pylori when ELISA was conducted using IVB or DBS stored at 4°C and transported even after 48 h. This confirms that DBS collected even in compromised conditions in the field can be used for detecting infection.

Optimization of extraction of genomic DNA from archived dried blood spot (DBS): potential application in epidemiological research & bio banking.

Background: Limited infrastructure is available to collect, store and transport venous blood in field epidemiological studies. Dried blood spot (DBS) is a robust potential alternative sample source for epidemiological studies & bio banking. A stable source of genomic DNA (gDNA) is required for long term storage in bio bank for its downstream applications. Our objective is to optimize the methods of gDNA extraction from stored DBS and with the aim of revealing its utility in large scale epidemiological studies.  Methods: The purpose of this study was to extract the maximum amount of gDNA from DBS on Whatman 903 protein saver card. gDNA was extracted through column  (Qiagen) & magnetic bead based (Invitrogen) methods. Quantification of extracted gDNA was performed with a spectrophotometer, fluorometer, and integrity analyzed by agarose gel electrophoresis.  Result: Large variation was observed in quantity & purity (260/280 ratio, 1.8-2.9) of the extracted gDNA. The intact gDNA bands on the electrophoresis gel reflect the robustness of DBS for gDNA even after prolonged storage time. The extracted gDNA amount 2.16 - 24 ng/µl is sufficient for its PCR based downstream application, but unfortunately it can't be used for whole genome sequencing or genotyping from extracted gDNA. Sequencing or genotyping can be achieved by after increasing template copy number through whole genome amplification of extracted gDNA. The obtained results create a base for future research to develop high-throughput research and extraction methods from blood samples. Conclusion: The above results reveal, DBS can be utilized as a potential and robust sample source for bio banking in field epidemiological studies.

Association of Genome-Wide Association Study (GWAS) Identified SNPs and Risk of Breast Cancer in an Indian Population.

To date, no studies have investigated the association of the GWAS-identified SNPs with BC risk in Indian population. We investigated the association of 30 previously reported and replicated BC susceptibility SNPs in 1,204 cases and 1,212 controls from a hospital based case-control study conducted at the Tata Memorial Hospital, Mumbai. As a measure of total susceptibility burden, the polygenic risk score (PRS) for each individual was defined by the weighted sum of genotypes from 21 independent SNPs with weights derived from previously published estimates of association odds-ratios. Logistic regression models were used to assess risk associated with individual SNPs and overall PRS, and stratified by menopausal and receptor status. A total of 11 SNPs from eight genomic regions (FGFR2, 9q31.2, MAP3K, CCND1, ZM1Z1, RAD51L11, ESR1 and UST) showed statistically significant (p-value ≤ 0.05) evidence of association, either overall or when stratified by menopausal status or hormone receptor status. BC SNPs previously identified in Caucasian population showed evidence of replication in the Indian population mainly with respect to risk of postmenopausal and hormone receptor positive BC.

Epidemiological review of gastric cancer in India.

Stomach cancer is the one of the leading cause of cancer in southern region of India. Its incidence is decreasing worldwide yet on global scale stomach cancer remains one of the most common causes of cancer death. Etiology of gastric cancer includes Helicobacter pylori infection, diet and lifestyle, tobacco, alcohol and genetic susceptibility. In this review, we tried to find the contribution of Indian scientist in understanding the descriptive and observational epidemiology of stomach cancer. PubMed was used as a search platform using key words such as "stomach cancer, treatment, clinical characteristics, stomach cancer outcome, epidemiology, etiological factor and their corresponding Mesh terms were used in combination with Boolean operators OR, AND". Most of the reported studies on gastric cancer from India are case report or case series and few are case-control studies. Indian studies on this topic are limited and have observed H. pylori infection, salted tea, pickled food, rice intake, spicy food, soda (additive of food), tobacco and alcohol as risk factors for gastric cancer. More research is required to understand the etiology, develop suitable screening test, to demarcate high-risk population and to develop and evaluate the effect of primary prevention programs.