Evaluation of Female Breast Cancer Risk Among the Betel Quid Chewer: A Bio-Statistical Assessment in Assam, India

Effects of smokeless tobacco on cancer incidence and mortality: a global systematic review and meta-analysis

INTRODUCTION

The prevalence of smokeless tobacco consumption remains high despite policies on reduction interventions. This study aims to quantify the associations between smokeless tobacco use with cancer incidence and mortality globally.

METHODS

We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and PROSPERO protocol (ID: CRD42023390468). A comprehensive literature search was performed using PubMed, Web of Science, and Scopus databases, covering the period from January 1, 2000, to February 28, 2023. We included peer-reviewed observational studies, specifically case-control and cohort studies, where smokeless tobacco use was the primary exposure and cancer incidence, or mortality were the main outcomes. Three independent reviewers screened titles, abstracts, and full texts, and extracted data from the included studies. Risk of bias was assessed by the same three reviewers. Any disagreements were resolved through discussion with a fourth reviewer. We performed random-effects meta-analyses and assessed heterogeneity and publication bias to ensure the robustness of our findings.

RESULTS

Of the 3,611 articles identified, 80 were included in the final analysis. Increased risks were observed for cancer mortality [Risk Ratio (RR) 1.38, 95% Confidence Interval (CI) 1.22-1.56] and incidence [RR 1.17, 95% CI 1.08-1.27]. The specific cancer sites with increased mortality risk included head and neck cancers, as well as stomach cancer. For cancer incidence, associations were observed with head and neck, oral, esophageal, stomach, and pancreatic cancers. Significant heterogeneity (I2 statistic 65% to 90%) was observed among most cancer outcomes.

CONCLUSION

Our study found significant associations between smokeless tobacco use and cancer incidence and mortality. Targeted policy interventions, such as stricter regulations on smokeless tobacco use, are recommended to reduce its consumption and mitigate the associated cancer risks.

Association of Tobacco Use and Cancer Incidence in India: A Systematic Review and Meta-Analysis

PURPOSE

To estimate the strength of the association between tobacco use and cancer incidence among the Indian population.

MATERIALS AND METHODS

Data from PubMed, Embase, and Virtual Health Library were searched from inception of databases till April 30, 2022. There were no restrictions except for English language and human study. Case-control and cohort studies on cancer incidence in relation to tobacco use were selected. Data were extracted independently by two investigators, and discrepancies were resolved by a third reviewer. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The quality assessment was done using the Newcastle Ottawa Scale.

RESULTS

The majority were case-control designs (60, 89.6%), covering diverse geographic regions, with Maharashtra (18, 30%) and Kerala (12, 20%) being the most studied. Pooled effect sizes were calculated using the random-effects model, and forest plots were generated. The risk of any cancer associated with smoked and smokeless tobacco was 2.71 (95% CI, 2.25 to 3.16) and 2.68 (95% CI, 2.22 to 3.14), respectively, indicating similar risks. Gender-wise, smoked tobacco had an association of 2.35 (95% CI, 2.05 to 2.65) for males, whereas for smokeless tobacco, it was 1.77 (95% CI, 1.47 to 2.07) for males and 2.34 (95% CI, 1.26 to 3.42) for females. Regardless of gender, tobacco type, and affected body parts, the risk of cancer due to tobacco use was consistent in the Indian population. Site-specific analysis showed higher risks of respiratory system cancers of 4.97 (95% CI, 3.62 to 6.32) and head and neck cancers of 3.95 (95% CI, 3.48 to 4.42).

CONCLUSION

This study underscores that both smoked and smokeless tobacco are equally harmful to human health among the Indian population, providing insights for stakeholders and policymakers to arrive at tobacco-specific interventions.

The Association between Mutational Signatures and Clinical Outcomes among Patients with Early-Onset Breast Cancer

Early-onset breast cancer (EoBC), defined by a diagnosis <40 years of age, is associated with poor prognosis. This study investigated the mutational landscape of non-metastatic EoBC and the prognostic relevance of mutational signatures using 100 tumour samples from Alberta, Canada. The MutationalPatterns package in R/Bioconductor was used to extract de novo single-base substitution (SBS) and insertion-deletion (indel) mutational signatures and to fit COSMIC SBS and indel signatures. We assessed associations between these signatures and clinical characteristics of disease, in addition to recurrence-free (RFS) and overall survival (OS). Five SBS and two indel signatures were extracted. The SBS13-like signature had higher relative contributions in the HER2-enriched subtype. Patients with higher than median contribution tended to have better RFS after adjustment for other prognostic factors (HR = 0.29; 95% CI: 0.08-1.06). An unsupervised clustering algorithm based on absolute contribution revealed three clusters of fitted COSMIC SBS signatures, but cluster membership was not associated with clinical variables or survival outcomes. The results of this exploratory study reveal various SBS and indel signatures may be associated with clinical features of disease and prognosis. Future studies with larger samples are required to better understand the mechanistic underpinnings of disease progression and treatment response in EoBC.

A Scoping Review on the Status of Female Breast Cancer in Asia with a Special Focus on Nepal

This study aimed to provide updated evidence on the status of female breast cancer and cancer treatment facilities in Asia, with a special focus on Nepal. This review used search phrases that included, breast neoplasm or cancer, health status, epidemiology, breast cancer survivors, cancer care facilities, Asia, Nepal. Researchers examined databases from January 2011 to December 2020 (PubMed, PMC, Google Scholar, and the reference lists of included papers). Studies of any design and reviews, were included in the study, except for qualitative studies. The study findings are presented in a narrative synthesis format using Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews. An initial search resulted in 974 papers, and 896 were reviewed after being checked for duplication using the Zotero software. Accordingly, utilizing the inclusion and exclusion criteria, 188 publications were selected, and after review of titles and abstracts, an additional 98 papers were removed for different reasons. Finally, the study looked at 90 female breast cancer papers. Results showed that the number of cases of breast cancer is growing all around the world, including in Asia and Nepal. Age, early menarche, late menopause, nulliparity, positive family history, excessive fat consumption, alcohol, and smoking are all frequent risk factors for breast cancer found in Asian women. Breast self-examination, clinical breast examination, and mammography screening are common methods for detecting breast carcinoma. Chemotherapy, radiation, and modified mastectomy are commonly used options for treatment. The number of breast cancer survivors is growing throughout the world, indicating better clinical care. There is a paucity of survival data in many Asian countries, including Nepal. There is also a scarcity of health workforce specialized in cancer care and treatment, as well as a few health facilities that are available to treat cancer cases in many Asian countries, including Nepal.

Arecoline promotes proliferation and migration of human HepG2 cells through activation of the PI3K/AKT/mTOR pathway

Background

Arecoline is a well-known risk factor for oral submucosal fibrosis and cancer. However, the mechanistic correlation between arecoline and hepatocellular cancer remains elusive. Here, we investigated the effect of arecoline on the proliferation and migration of human HepG2 hepatoma cells and its potential oncogenic mechanisms.

Methods

Bioinformatic technologies were used to identify the deferentially expressed miRNAs (DE-miRNAs) and hub target genes of arecoline-induced cancers. These DE-miRNAs, hub genes and pathway were proved in arecoline-treated HepG2 cells.

Results

A total of 86 DE-miRNAs and 460 target genes were identified. These target genes are associated with DNA-templated regulation of transcription and other biological processes. Significant molecular functions were protein binding, calcium ion binding, and enrichment in the nucleus and cytoplasm. These genes are involved in the PI3K-AKT pathway. CDK1, CCND1, RAF1, CDKN1B and BTRC were defined as the top 5 hub target genes, and patients with high expression of CDK1 showed poor prognosis. Compared with control group, 2.5 µM arecoline treatment increased the proliferation and migration ability of the HepG2 cells. Treatment with 2.5 µM arecoline increased the levels of miR-21-3p, miR-21-5p and miR-1267, upregulated the expression of PI3K-AKT pathway factors, CDK1, CCND1 but decreased RAF1 expression.

Conclusion

A low concentration arecoline can induce the proliferation and migration of HepG2 cells, with the potential mechanism of action linked to high levels of exosomal miR-21 and miR-1267, activation of the PI3K-AKT pathway, upregulation of CDK1 and CCND1, and downregulation of RAF1.

The health impact of smokeless tobacco products: a systematic review

INTRODUCTION

The objective was to systematically review studies on health outcomes from smokeless tobacco (SLT) products.

METHODS

We analysed published literature on the health outcomes from SLT use between 01/01/2015 to 01/02/2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol using PubMed, Embase, Scopus, and Google Scholar.

RESULTS

Of 53 studies included, six were global, 32 from Asia, Middle East and Africa (AMEA), nine from USA and six from Europe. 'Poor'-rated studies predominated (23;43%), in particular, for global (4;66%) and AMEA (16;50%). Health outcomes differed between SLT-products and regions; those in AMEA were associated with higher mortality (overall, cancer, Coronary heart disease (CHD), respiratory but not cardiovascular disease (CVD)), and morbidity (CVD, oral and head and neck cancers), with odds ratios up to 38.7. European studies showed no excess mortality (overall, CVD, from cancers) or morbidity (ischemic heart disease (IHD), stroke, oral, head and neck, pancreatic or colon cancers) from several meta-analyses; single studies reported elevated risk of rectal cancer and respiratory disorders. Pooled study data showed protection against developing Parkinson's disease. US studies showed mixed results for mortality (raised overall, CHD, cancer and smoking-related cancer mortality; no excess risk of respiratory or CVD mortality). Morbidity outcomes were also mixed, with some evidence of increased IHD, stroke and cancer risk (oral, head and neck). No studies reported on switching from cigarettes to SLT-products.

CONCLUSION

Our review demonstrates stark differences between different SLT-products in different regions, ranging from zero harm from European snus to greatly increased health risks in AMEA. The literature on the safety profile for SLT-products for harm reduction is incomplete and potentially misinforming policy and regulation.

Betel Nut Use in Vanuatu: Investigating Opportunities to Reduce Harms to Health

Background: Betel nut chewing is a public health concern in the Asia-Pacific region and is an emerging issue in Vanuatu. Despite the significant health risks associated with betel nut chewing, few interventions have been undertaken to reduce its harm. Objectives: To investigate betel nut use in Vanuatu and to identify opportunities to reduce its harm and possible interventions, framing the responses using the World Health Organization's MPOWER tobacco control model. Method: Qualitative research design, in the form of semi-structured interviews with ten participants with expertise in health, agriculture, education or non-communicable disease in Port Vila, Vanuatu during June 2017. Recorded interviews were transcribed verbatim, and a general inductive approach was used to identify key themes. Results: Participants reported a recent increase in betel nut use in Vanuatu due to the influence from Papua New Guinea and the Solomon Islands. To reduce the harm of betel nut use in Vanuatu, participants suggested policies and strategies that aligned with the MPOWER framework that could be adopted for betel nut control, including restricting cultivation and sale of betel nut in Vanuatu and using radio and existing community networks to reach people with messages about the dangers of betel nut use. Conclusion: Betel nut use may be growing in popularity in Vanuatu, where there are potential policy options to minimize harm. The MPOWER model for tobacco control may be a useful framework to help the Vanuatu government to deliver a comprehensive approach to reducing harm from betel nut use.

Investigating Betel Nut Use, Antecedents and Consequences: A Review of Literature

Background: Betel nut use is a public health issue in the Asia-Pacific region that is often neglected. To control betel nut use, understanding of the adverse effects of betel nut use and evidence-based policies and strategies is necessary. Objectives: This narrative review aims to characterize the current situation on betel nut use at a global level regarding the epidemiology, pharmacology and toxicology, health effects, treatment options, policies and strategies. Methods: We found 139 existing literature published between 1970-2019 on the Web of Science database and other technical documents to collate the most relevant information on betel nut use. Data were categorized into appropriate themes. Results: The literature demonstrates that there is a lack of up to date statistics on betel nut use. There is limited research on the effect of policies and strategies to control betel nut use. Conclusion: Betel nut-chewing countries should focus on understanding which populations chew betel nut and implement appropriate policies, educational and cessation programs to help control betel nut use.

Relationship between type of smokeless tobacco & risk of cancer: A systematic review

BACKGROUND & OBJECTIVES

Causative linkages of smokeless tobacco (SLT) use with oral potentially malignant disorders and cancers of oral cavity, oesophagus and pancreas have been reported. Published meta-analyses have provided pooled risk estimates for major cancers caused by SLT, both on global and regional levels. This systematic review was aimed at summarizing the available studies on occurrence and mortality risk of common cancers due to various SLT products.

METHODS

PubMed and Google Scholar databases were systematically searched from 1985 till January 2018 for observational studies on SLT and cancer. The included studies were evaluated and data were extracted and reviewed.

RESULTS

The review included 80 studies providing 121 risk estimates for various cancers. Majority of the studies from South-East Asian Region (SEAR) and Eastern Mediterranean Region (EMR) showed a significant positive association of SLT use with oral [odds ratio (OR) ranging from 1.48 to 27.4] and oesophageal cancers (OR between 2.06 and 12.8), while studies from European Region (EUR) reported a positive association with pancreatic cancer (OR between 1.6 and 2.1). Cancer-related mortality was evaluated in a few reports with higher risk of mortality for lung (OR between 2.0 and 9.1), cervical (OR 2.0) and prostate (OR 2.1) cancers. A wide variation was noted in the association of various cancers and specific SLT products based on their nature, methods of use and inherent toxicity. The majority of chewing tobacco products displayed higher risk for oral and oesophageal cancers while the same was not observed for snus.

INTERPRETATION & CONCLUSIONS

This review emphasizes on the significantly positive association of SLT use with oral and oesophageal cancers in SEAR and EMR and pancreatic cancer in EUR. Mortality estimates for SLT-associated cancers need further analysis. Risk analysis for cancers of other sites in SLT users also requires multicentric well-designed studies.