Global burden of oral cancer in 2022 attributable to smokeless tobacco and areca nut consumption: a population attributable fraction analysis.

BACKGROUND: Consuming products that contain smokeless tobacco or areca nut increases the risk of oral cancer. We aimed to estimate the burden of oral cancer attributable to smokeless tobacco or areca nut consumption globally and by type of smokeless tobacco or areca nut product in four major consuming countries. METHODS: We calculated population attributable fractions (PAFs) using prevalence of current use of smokeless tobacco or areca nut products from national surveys and corresponding risks of oral cancer from the literature. We applied PAFs to national estimates of oral cancer incidence in 2022 from the Global Cancer Observatory's Cancer Today database to obtain cases attributable to smokeless tobacco or areca nut consumption. We modelled 95% uncertainty intervals (UIs) using Monte Carlo simulations. FINDINGS: Globally, an estimated 120 200 (95% UI 115 300-124 300) cases of oral cancer diagnosed in 2022 were attributable to smokeless tobacco or areca nut consumption, accounting for 30·8% (95% UI 29·6-31·9) of all oral cancer cases (120 200 of 389 800). An estimated 77% of attributable cases were among male patients (92 600 cases, 95% UI 88 000-96 500) and 23% were among female patients (27 600 cases, 26 000-29 000). Regions with the highest PAFs were Melanesia, Micronesia, and Polynesia (78·6%, 95% UI 74·4-80·5), southcentral Asia (57·5%, 54·8-59·5), and southeastern Asia (19·8%, 19·0-20·6). Lower-middle-income countries represented 90·2% of the world total attributable cases (108 400 cases, 95% UI 103 400-112 200). INTERPRETATION: Our findings suggest that one in three cases of oral cancer globally are attributable to smokeless tobacco or areca nut consumption, and could be prevented through smokeless tobacco and areca nut control. Global cancer control efforts must incorporate further measures to reduce smokeless tobacco and areca nut consumption in populations with the largest attributable burden. FUNDING: French National Cancer Institute.

Global burden of bladder cancer mortality in 2020 and 2040 according to GLOBOCAN estimates.

INTRODUCTION: In 2020, bladder cancer (BC) was the seventh most prevalent cancer in the world, with 5-year prevalence of more than 1.7 million cases. Due to the main risk factors-smoking and chemical exposures-associated with BC, it is considered a largely preventable and avoidable cancer. An overview of BC mortality can allow an insight not only into the prevalence of global risk factors, but also into the varying efficiency of healthcare systems worldwide. For this purpose, this study analyzes the national mortality estimates for 2020 and projected future trends up to 2040. MATERIALS AND METHODS: Age-standardized mortality rates per 100,000 person-years of BC for 185 countries by sex were obtained from the GLOBOCAN 2020 database, operated by the International Agency for Research on Cancer (IARC). Mortality rates were stratified according to sex and Human Development Index (HDI). BC deaths were projected up to 2040 on the basis of demographic changes, alongside different scenarios of annually increasing, stable or decreasing mortality rates from the baseline year of 2020. RESULTS: In 2020, nearly three times more men died from BC than women, with more than 210,000 deaths in both sexes combined, worldwide. Regardless of gender, more than half of the total BC deaths were from countries with a very high HDI. According to our projections, while the number of deaths for men can only increase up to 54% (from 159 to around 163-245 thousand), for women it is projected to increase two- to three-fold (from 50 to around 119-176 thousand) by 2040. The burden of BC mortality in countries with a very high HDI versus high HDI appears to converge by 2040 for both sexes. CONCLUSION: Opposite mortality trends by gender highlight the urgent need for immediate interventions to expand anti-tobacco strategies, especially for women. The implementation of more strict occupational health and safety regulations could also prevent exposures associated with BC. Improving the ability to detect BC earlier and access to treatment can have a significant positive impact on reducing mortality rates, minimizing economic costs, and enhancing the quality of life for patients.

Global burden of colorectal cancer in 2020 and 2040: incidence and mortality estimates from GLOBOCAN.

OBJECTIVE: Colorectal cancer (CRC) is the third most common cancer worldwide. The geographical and temporal burden of this cancer provides insights into risk factor prevalence and progress in cancer control strategies. We examine the current and future burden of CRC in 185 countries in 2020 and 2040. METHODS: Data on CRC cases and deaths were extracted from the GLOBOCAN database for the year 2020. Age-standardised incidence and mortality rates were calculated by sex, country, world region and Human Development Index (HDI) for 185 countries. Age-specific rates were also estimated. The predicted number of cases and deaths in 2040 were calculated based on global demographic projections by HDI. RESULTS: Over 1.9 million new CRC cases and 930 000 deaths were estimated in 2020. Incidence rates were highest in Australia/ New Zealand and European regions (40.6 per 100 000, males) and lowest in several African regions and Southern Asia (4.4 per 100 000, females). Similar patterns were observed for mortality rates, with the highest observed in Eastern Europe (20.2 per 100 000, males) and the lowest in Southern Asia (2.5 per 100 000, females). The burden of CRC is projected to increase to 3.2 million new cases and 1.6 million deaths by 2040 with most cases predicted to occur in high or very high HDI countries. CONCLUSIONS: CRC is a highly frequent cancer worldwide, and largely preventable through changes in modifiable risk factors, alongside the detection and removal of precancerous lesions. With increasing rates in transitioning countries and younger adults, there is a pressing need to better understand and act on findings to avert future cases and deaths from the disease.

The Global Landscape of Esophageal Squamous Cell Carcinoma and Esophageal Adenocarcinoma Incidence and Mortality in 2020 and Projections to 2040: New Estimates From GLOBOCAN 2020.

BACKGROUND & AIMS: The aim of this study was to provide an overview of the burden of esophageal cancer in 185 countries in 2020 and projections for the year 2040. METHODS: Estimates of esophageal cancer cases and deaths were extracted from the GLOBOCAN database for 2020. Age-standardized incidence and mortality rates were calculated overall, by sex, histologic subtype (adenocarcinoma [AC] and squamous cell carcinoma [SCC]), country, and level of human development for 185 countries. The predicted burden of incidence and mortality in 2040 was calculated based on global demographic projections. RESULTS: Globally, there were an estimated 604,100 new cases of, and 544,100 deaths from, esophageal cancer in 2020, corresponding to age-standardized incidence and mortality rates of 6.3 and 5.6 per 100,000, respectively. Most cases were SCCs (85% [512,500 cases]) and 14% (85,700 cases) were ACs. Incidence and mortality rates were 2- to 3-fold higher in male (9.3 and 8.2, respectively) compared with female (3.6 and 3.2, respectively) individuals. Global variations in incidence and mortality were observed across countries and world regions; the highest rates occurred in Eastern Asia and Southern and Eastern Africa and the lowest occurred in Western Africa and Central America regions. If rates remain stable, 957,000 new cases (141,300 AC cases and 806,000 SCC cases) and 880,000 deaths from esophageal cancer are expected in 2040. CONCLUSIONS: These updated estimates of the global burden of esophageal cancer represent an important baseline for setting priorities in policy making and developing and accelerating cancer control initiatives to reduce the current and projected burden. Although primary prevention remains key, screening and early detection represent important components of esophageal cancer control in high-risk populations.

Ovarian cancer today and tomorrow: A global assessment by world region and Human Development Index using GLOBOCAN 2020.

Ovarian cancer remains to have relatively poor prognosis particularly in low-resourced settings. It is therefore important to continually examine the burden of ovarian cancer to identify areas of disparities. Our study aims to provide an overview of the global burden of ovarian cancer using the GLOBOCAN 2020 estimates by country, world region, and Human Development Index (HDI) levels, as well as the predicted future burden by the year 2040 by HDI. Age-standardized incidence and mortality rates for ovarian cancer in 185 countries were calculated by country, world region, and for the four-tier HDI. The number of new cases and deaths were projected for the year 2040 based on demographic projections by HDI category. Approximately 314 000 new ovarian cancer cases and 207 000 deaths occurred in 2020. There were marked geographic variations in incidence rates, with the highest rates observed in European countries with very high HDI and low rates were found in African countries within the lowest HDI group. Comparable mortality rates were observed across the four-tier HDI. Relative to 2020 estimates, our projection for 2040 indicates approximately 96% and 100% increase in new ovarian cancer cases and deaths, respectively, among low HDI countries compared to 19% and 28% in very high HDI countries. Our study highlights the disproportionate current and future burden of ovarian cancer in countries with lower HDI levels, calling for global action to reduce the burden and inequality of ovarian cancer in access to quality cancer care and treatment.

Global burden of primary liver cancer in 2020 and predictions to 2040.

BACKGROUND & AIMS: The burden of liver cancer varies across the world. Herein, we present updated estimates of the current global burden of liver cancer (incidence and mortality) and provide predictions of the number of cases/deaths to 2040. METHODS: We extracted data on primary liver cancer cases and deaths from the GLOBOCAN 2020 database, which includes 185 countries. Age-standardised incidence and mortality rates (ASRs) per 100,000 person-years were calculated. Cases and deaths up to the year 2040 were predicted based on incidence and mortality rates for 2020 and global demographic projections to 2040. RESULTS: In 2020, an estimated 905,700 people were diagnosed with, and 830,200 people died from, liver cancer globally. Global ASRs for liver cancer were 9.5 and 8.7 for new cases and deaths, respectively, per 100,000 people and were highest in Eastern Asia (17.8 new cases, 16.1 deaths), Northern Africa (15.2 new cases, 14.5 deaths), and South-Eastern Asia (13.7 new cases, 13.2 deaths). Liver cancer was among the top three causes of cancer death in 46 countries and was among the top five causes of cancer death in 90 countries. ASRs of both incidence and mortality were higher among males than females in all world regions (male:female ASR ratio ranged between 1.2-3.6). The number of new cases of liver cancer per year is predicted to increase by 55.0% between 2020 and 2040, with a possible 1.4 million people diagnosed in 2040. A predicted 1.3 million people could die from liver cancer in 2040 (56.4% more than in 2020). CONCLUSIONS: Liver cancer is a major cause of death in many countries, and the number of people diagnosed with liver cancer is predicted to rise. Efforts to reduce the incidence of preventable liver cancer should be prioritised. LAY SUMMARY: The burden of liver cancer varies across the world. Liver cancer was among the top three causes of cancer death in 46 countries and was among the top five causes of cancer death in 90 countries worldwide. We predict the number of cases and deaths will rise over the next 20 years as the world population grows. Primary liver cancer due to some causes is preventable if control efforts are prioritised and the predicted rise in cases may increase the need for resources to manage care of patients with liver cancer.

Estimated global cancer incidence in the oldest adults in 2018 and projections to 2050.

Using GLOBOCAN estimates, we describe the estimated cancer incidence among adults aged 80 years or older at the regional and global level in 2018, reporting the number of new cancer cases, and the truncated age-standardised incidence rates (per 100 000) for all cancer sites combined for this age group. We also presented the five most frequent cancers diagnosed by region and globally among females and males aged 65 to 79 years old and 80 years or older. We, finally, estimated the number of new cancer cases in 2050, the proportion of cases aged 80 years or older, and the proportional increase between 2018 and 2050 by region, by applying population projections to the 2018 incidence rates. In 2018, an estimated 2.3 million new cancer cases (excluding nonmelanoma skin cancers) were aged 80 years or older worldwide (13% of all cancer cases), with large variation in the profiles at regional levels. Globally, breast, lung and colon were the most common cancer sites diagnosed in the oldest females, while prostate, lung and colon were most frequent in the oldest males. In 2050, an estimated 6.9 million new cancers will be diagnosed in adults aged 80 years or older worldwide (20.5% of all cancer cases). Due to the complexity of cancer management in the oldest patients, the expected increase will challenge healthcare systems worldwide, posing a tangible economic and social impact on families and society. It is time to consider the oldest population in cancer control policies.

Global Burden of 5 Major Types of Gastrointestinal Cancer.

BACKGROUND & AIMS: There were an estimated 4.8 million new cases of gastrointestinal (GI) cancers and 3.4 million related deaths, worldwide, in 2018. GI cancers account for 26% of the global cancer incidence and 35% of all cancer-related deaths. We investigated the global burden from the 5 major GI cancers, as well as geographic and temporal trends in cancer-specific incidence and mortality. METHODS: Data on primary cancers of the esophagus, stomach, colorectum, liver, and pancreas were extracted from the GLOBOCAN database for the year 2018, as well as from the Cancer Incidence in 5 Continents series, and the World Health Organization mortality database from 1960 onward. Age-standardized incidence and mortality rates were calculated by sex, country, and level of human development. RESULTS: We observed geographic and temporal variations in incidence and mortality for all 5 types of GI cancers. Esophageal, gastric, and liver cancers were more common in Asia than in other parts of the world, and the burden from colorectal and pancreatic cancers was highest in Europe and North America. There was a uniform decrease in gastric cancer incidence, but an increasing incidence of colorectal cancer in formerly low-incidence regions during the studied time period. We found slight increases in incidence of liver and pancreatic cancer in some high-income regions. CONCLUSIONS: Although the incidence of some GI cancer types has decreased, this group of malignancies continues to pose major challenges to public health. Primary and secondary prevention measures are important for controlling these malignancies-most importantly reducing consumption of tobacco and alcohol, obesity control, immunizing populations against hepatitis B virus infection, and screening for colorectal cancer.

Proportion of cancers attributable to major lifestyle and environmental risk factors in the Eastern Mediterranean region.

Cancer is a major contributing cause of morbidity and mortality in the Eastern Mediterranean region. The aim of the current study was to estimate the cancer burden attributable to major lifestyle and environmental risk factors. We used age-, sex- and site-specific incidence estimates for 2012 from IARC's GLOBOCAN, and assessed the following risk factors: smoking, alcohol, high body mass index, insufficient physical activity, diet, suboptimal breastfeeding, infections and air pollution. The prevalence of exposure to these risk factors came from different sources including peer-reviewed international literature, the World Health Organization, noncommunicable disease Risk Factor Collaboration, and the Food and Agriculture Organization. Sex-specific population-attributable fraction was estimated in the 22 countries of the Eastern Mediterranean region based on the prevalence of the selected risk factors and the relative risks obtained from meta-analyses. We estimated that approximately 33% (or 165,000 cases) of all new cancer cases in adults aged 30 years and older in 2012 were attributable to all selected risk factors combined. Infections and smoking accounted for more than half of the total attributable cases among men, while insufficient physical activity and exposure to infections accounted for more than two-thirds of the total attributable cases among women. A reduction in exposure to major lifestyle and environmental risk factors could prevent a substantial number of cancer cases in the Eastern Mediterranean. Population-based programs preventing infections and smoking (particularly among men) and promoting physical activity (particularly among women) in the population are needed to effectively decrease the regional cancer burden.

Global cancer incidence in older adults, 2012 and 2035: A population-based study.

Population ageing has substantially contributed to the rising number of new cancer cases worldwide. We document cancer incidence patterns in 2012 among older adults globally, and examine the changing magnitude of cancer in this age group over the next decades. Using GLOBOCAN 2012 data, we presented the number and proportion of new cancer cases, and the truncated age-standardised incidence rates among adults aged 65 years and older for all cancer sites combined and for the five most common cancer sites by world region. We calculated the incidence in 2035 by applying population projections, assuming no changes in rates. In 2012, 6.7 million new cancer cases (47.5% of all cancers) were diagnosed among older adults worldwide, with marked regional disparities. Nearly 48% of these cases occurred in less developed regions. Lung, colorectal, prostate, stomach and breast cancers represented 55% of the global incidence, yet distinct regional patterns were observed. We predict 14 million new cancer cases by 2035, representing almost 60% of the global cancer incidence. The largest relative increase in incidence is predicted in the Middle East and Northern Africa (+157%), and in China (+155%). Less developed regions will see an increase of new cases by 144%, compared to 54% in more developed regions. The expected increase in cancer incidence at older ages will have substantial economic and social impacts globally, posing considerable and unique challenge to healthcare systems in every world region, especially in those with limited resources and weaker health systems.

The risk of cancer attributable to diagnostic medical radiation: Estimation for France in 2015.

Although medical ionizing radiation (IR) has clear clinical benefits, it is an established carcinogen. Our study estimates the number of new cancer cases in France in 2015 attributable to IR exposure from medical procedures. Exposures from external (X-rays, CT scans, interventional radiology) and internal (nuclear medicine) sources were considered. We used 2007 national frequencies of diagnostic examinations by sex and age to estimate the lifetime organ dose exposure adjusted for changes in the use of such procedures over time. The Biological Effects of Ionizing Radiation VII risk models were used to estimate the corresponding excess cancer risk, assuming an average latency period of 10 years. Additionally, we used cancer incidence data from the French Cancer Registries Network. Of the 346,000 estimated new cancer cases in adults in France in 2015, 2300 cases (940 among men and 1360 among women) were attributable to diagnostic IR, representing 0.7% of all new cancer cases (0.5% for men and 0.9% for women). The leading cancers attributable to medical IR were female breast (n = 560 cases), lung (n = 500 cases) and colon (n = 290 cases) cancers. Compared to other risk factors, the contribution of medical IR to the cancer burden is small, and the benefits largely outweigh its harms. However, some of these IR-associated cancer cases may be preventable through dose optimization of and enhanced justification for diagnostic examinations.

New cancer cases in France in 2015 attributable to infectious agents: a systematic review and meta-analysis.

To provide an assessment of the burden of cancer in France in 2015 attributable to infectious agents. A systematic literature review in French representative cancer cases series was undertaken of the prevalence of infectious agents with the major associated cancer types. PubMed was searched for original studies published up to September 2016; random-effects meta-analyses were performed. Cancer incidence data were obtained from the French Cancer Registries Network, thereby allowing the calculation of national incidence estimates. The number of new cancer cases attributable to infectious agents was calculated using population-attributable fractions according to published methods. Of the 352,000 new cancer cases in France in 2015, 14,336 (4.1% of all new cancer cases) were attributable to infectious agents. The largest contributors were human papillomavirus (HPV) and Helicobacter pylori, responsible for 6333 and 4406 new cancer cases (1.8 and 1.3% of all new cancer cases) respectively. Infectious agents caused a non-negligible number of new cancer cases in France in 2015. Most of these cancers were preventable. The expansion of vaccination (i.e., for hepatitis B virus and HPV) and screen-and-treat programs (for HPV and hepatitis C virus, and possibly for H. pylori) could greatly reduce this cancer burden.

Worldwide burden of cancer attributable to HPV by site, country and HPV type.

HPV is the cause of almost all cervical cancer and is responsible for a substantial fraction of other anogenital cancers and oropharyngeal cancers. Understanding the HPV-attributable cancer burden can boost programs of HPV vaccination and HPV-based cervical screening. Attributable fractions (AFs) and the relative contributions of different HPV types were derived from published studies reporting on the prevalence of transforming HPV infection in cancer tissue. Maps of age-standardized incidence rates of HPV-attributable cancers by country from GLOBOCAN 2012 data are shown separately for the cervix, other anogenital tract and head and neck cancers. The relative contribution of HPV16/18 and HPV6/11/16/18/31/33/45/52/58 was also estimated. 4.5% of all cancers worldwide (630,000 new cancer cases per year) are attributable to HPV: 8.6% in women and 0.8% in men. AF in women ranges from <3% in Australia/New Zealand and the USA to >20% in India and sub-Saharan Africa. Cervix accounts for 83% of HPV-attributable cancer, two-thirds of which occur in less developed countries. Other HPV-attributable anogenital cancer includes 8,500 vulva; 12,000 vagina; 35,000 anus (half occurring in men) and 13,000 penis. In the head and neck, HPV-attributable cancers represent 38,000 cases of which 21,000 are oropharyngeal cancers occurring in more developed countries. The relative contributions of HPV16/18 and HPV6/11/16/18/31/33/45/52/58 are 73% and 90%, respectively. Universal access to vaccination is the key to avoiding most cases of HPV-attributable cancer. The preponderant burden of HPV16/18 and the possibility of cross-protection emphasize the importance of the introduction of more affordable vaccines in less developed countries.

Global burden of gastric cancer attributable to Helicobacter pylori.

We previously estimated that 660,000 cases of cancer in the year 2008 were attributable to the bacterium Helicobacter pylori (H. pylori), corresponding to 5.2% of the 12.7 million total cancer cases that occurred worldwide. In recent years, evidence has accumulated that immunoblot (western blot) is more sensitive for detection of anti-H. pylori antibodies than ELISA, the detection method used in our previous analysis. The purpose of this short report is to update the attributable fraction (AF) estimate for H. pylori after briefly reviewing new evidence, and to reassess the global burden of cancer attributable to H. pylori. We therefore reviewed the literature for studies comparing the risk of developing non-cardia gastric cancer (NCGC) in cases and controls, using both ELISA and multiple antigen immunoblot for detection of H. pylori. The results from prospective studies were combined, and the new pooled estimates were applied to the calculation of the AF for H. pylori in NCGC, then to the burden of infection-related cancers worldwide. Using the immunoblot-based data, the worldwide AF for H. pylori in NCGC increased from 74.7% to 89.0%. This implies approximately 120,000 additional cases of NCGC attributable to H. pylori infection for a total of around 780,000 cases (6.2% instead of 5.2% of all cancers). These updated estimates reinforce the role of H. pylori as a major cause of cancer.

Global Stage Distribution of Breast Cancer at Diagnosis: A Systematic Review and Meta-Analysis.

Importance: Stage at diagnosis is a key prognostic factor for cancer survival. Objective: To assess the global distribution of breast cancer stage by country, age group, calendar period, and socioeconomic status using population-based data. Data Sources: A systematic search of MEDLINE and Web of Science databases and registry websites and gray literature was conducted for articles or reports published between January 1, 2000, and June 20, 2022. Study Selection: Reports on stage at diagnosis for individuals with primary breast cancer (C50) from a population-based cancer registry were included. Data Extraction and Synthesis: Study characteristics and results of eligible studies were independently extracted by 2 pairs of reviewers (J.D.B.F., A.D.A., A.M., R.S., and F.G.). Stage-specific proportions were extracted and cancer registry data quality and risk of bias were assessed. National pooled estimates were calculated for subnational or annual data sets using a hierarchical rule of the most relevant and high-quality data to avoid duplicates. Main Outcomes and Measures: The proportion of women with breast cancer by (TNM Classification of Malignant Tumors or the Surveillance, Epidemiology, and End Results Program [SEER]) stage group. Results: Data were available for 2.4 million women with breast cancer from 81 countries. Globally, the proportion of cases with distant metastatic breast cancer at diagnosis was high in sub-Saharan Africa, ranging from 5.6% to 30.6% and low in North America ranging from 0.0% to 6.0%. The proportion of patients diagnosed with distant metastatic disease decreased over the past 2 decades from around 3.8% to 35.8% (early 2000s) to 3.2% to 11.6% (2015 onwards), yet stabilization or slight increases were also observed. Older age and lower socioeconomic status had the largest proportion of cases diagnosed with distant metastatic stage ranging from 2.0% to 15.7% among the younger to 4.1% to 33.9% among the oldest age group, and from 1.7% to 8.3% in the least disadvantaged groups to 2.8% to 11.4% in the most disadvantaged groups. Conclusions and Relevance: Effective policy and interventions have resulted in decreased proportions of women diagnosed with metastatic breast cancer at diagnosis in high-income countries, yet inequality persists, which needs to be addressed through increased awareness of breast cancer symptoms and early detection. Improving global coverage and quality of population-based cancer registries, including the collection of standardized stage data, is key to monitoring progress.

The current and future cancer burden in the Gulf Cooperation Council (GCC) countries.

BACKGROUND: Cancer is a leading cause of morbidity and mortality in the Gulf Cooperation Council (GCC) countries. This study aims to provide cancer incidence and mortality estimates in 2020 in the GCC countries alongside future projections for 2040 to shape cancer control policy in the region. METHODS: The estimated numbers of new cancer cases and deaths were extracted from the GLOBOCAN database developed by the International Agency for Research on Cancer; new cancer cases, cancer deaths, and corresponding age-standardized incidence and mortality rates for the year 2020 are presented. RESULTS: An estimated 42,475 new cancer cases and 19,895 deaths occurred in the GCC countries in 2020, with corresponding age-standardized incidence and mortality rates of 96.5 and 52.3 per 100,000, respectively. Female breast (16%), colorectal (13%), and thyroid (9%) were the most common types of cancer in the GCC countries, accounting for almost 40% of all cancer incidence. Colorectal (14%) followed by breast cancer (9%) were the leading causes of cancer death, though the magnitude of rates of the major cancer types varied substantially across the GCC countries. Even if we assume rates in the region will remain unchanged over the next two decades, the cancer burden in the GCC will increase by 116% (Saudi Arabia) to 270% (Qatar), reaching nearly 104,000 cancer cases by the year 2040. CONCLUSION: The sharp increase in the estimated cancer incidence and mortality predicted over the next decades in the region requires workforce and financial planning for the healthcare systems in the constituent countries, alongside broader strengthening of national cancer prevention and control efforts.

Human papillomavirus type 16 genetic variants: phylogeny and classification based on E6 and LCR.

Naturally occurring genetic variants of human papillomavirus type 16 (HPV16) are common and have previously been classified into 4 major lineages; European-Asian (EAS), including the sublineages European (EUR) and Asian (As), African 1 (AFR1), African 2 (AFR2), and North-American/Asian-American (NA/AA). We aimed to improve the classification of HPV16 variant lineages by using a large resource of HPV16-positive cervical samples collected from geographically diverse populations in studies on HPV and/or cervical cancer undertaken by the International Agency for Research on Cancer. In total, we sequenced the entire E6 genes and long control regions (LCRs) of 953 HPV16 isolates from 27 different countries worldwide. Phylogenetic analyses confirmed previously described variant lineages and subclassifications. We characterized two new sublineages within each of the lineages AFR1 and AFR2 that are robustly classified using E6 and/or the LCR. We could differentiate previously identified AA1, AA2, and NA sublineages, although they could not be distinguished by E6 alone, requiring the LCR for correct phylogenetic classification. We thus provide a classification system for HPV16 genomes based on 13 and 32 phylogenetically distinguishing positions in E6 and the LCR, respectively, that distinguish nine HPV16 variant sublineages (EUR, As, AFR1a, AFR1b, AFR2a, AFR2b, NA, AA1, and AA2). Ninety-seven percent of all 953 samples fitted this classification perfectly. Other positions were frequently polymorphic within one or more lineages but did not define phylogenetic subgroups. Such a standardized classification of HPV16 variants is important for future epidemiological and biological studies of the carcinogenic potential of HPV16 variant lineages.

Global burden of cancers attributable to infections in 2008: a review and synthetic analysis.

BACKGROUND: Infections with certain viruses, bacteria, and parasites have been identified as strong risk factors for specific cancers. An update of their respective contribution to the global burden of cancer is warranted. METHODS: We considered infectious agents classified as carcinogenic to humans by the International Agency for Research on Cancer. We calculated their population attributable fraction worldwide and in eight geographical regions, using statistics on estimated cancer incidence in 2008. When associations were very strong, calculations were based on the prevalence of infection in cancer cases rather than in the general population. Estimates of infection prevalence and relative risk were extracted from published data. FINDINGS: Of the 12·7 million new cancer cases that occurred in 2008, the population attributable fraction (PAF) for infectious agents was 16·1%, meaning that around 2 million new cancer cases were attributable to infections. This fraction was higher in less developed countries (22·9%) than in more developed countries (7·4%), and varied from 3·3% in Australia and New Zealand to 32·7% in sub-Saharan Africa. Helicobacter pylori, hepatitis B and C viruses, and human papillomaviruses were responsible for 1·9 million cases, mainly gastric, liver, and cervix uteri cancers. In women, cervix uteri cancer accounted for about half of the infection-related burden of cancer; in men, liver and gastric cancers accounted for more than 80%. Around 30% of infection-attributable cases occur in people younger than 50 years. INTERPRETATION: Around 2 million cancer cases each year are caused by infectious agents. Application of existing public health methods for infection prevention, such as vaccination, safer injection practice, or antimicrobial treatments, could have a substantial effect on the future burden of cancer worldwide. FUNDING: Fondation Innovations en Infectiologie (FINOVI) and the Bill & Melinda Gates Foundation (BMGF).

Quantitative estimates of preventable and treatable deaths from 36 cancers worldwide: a population-based study.

BACKGROUND: Cancer is a leading cause of premature mortality globally. This study estimates premature deaths at ages 30-69 years and distinguishes these as deaths that are preventable (avertable through primary or secondary prevention) or treatable (avertable through curative treatment) in 185 countries worldwide. METHODS: For this population-based study, estimated cancer deaths by country, cancer, sex, and age groups were retrieved from the International Agency for Research on Cancer's GLOBOCAN 2020 database. Crude and age-adjusted cancer-specific years of life lost (YLLs) were calculated for 36 cancer types. FINDINGS: Of the estimated all-ages cancer burden of 265·6 million YLLs, 182·8 million (68·8%) YLLs were due to premature deaths from cancer globally in 2020, with 124·3 million (68·0%) preventable and 58·5 million (32·0%) treatable. Countries with low, medium, or high human development index (HDI) levels all had greater proportions of YLLs at premature ages than very high HDI countries (68·9%, 77·0%, and 72·2% vs 57·7%, respectively). Lung cancer was the leading contributor to preventable premature YLLs in medium to very high HDI countries (17·4% of all cancers, or 29·7 million of 171·3 million YLLs), whereas cervical cancer led in low HDI countries (26·3% of all preventable cancers, or 1·83 million of 6·93 million YLLs). Colorectal and breast cancers were major treatable cancers across all four tiers of HDI (25·5% of all treatable cancers in combination, or 14·9 million of 58·5 million YLLs). INTERPRETATION: Alongside tailored programmes of early diagnosis and screening linked to timely and comprehensive treatment, greater investments in risk factor reduction and vaccination are needed to address premature cancer inequalities. FUNDING: Erasmus Mundus Exchange Programme and the International Agency for Research on Cancer. TRANSLATIONS: For the German, French, Spanish and Chinese translations of the abstract see Supplementary Materials section.