Smoking, alcohol use, being overweight and other known risk factors were responsible for nearly 4.45 million cancer deaths worldwide in 2019, according to new research published in The Lancet, based on the study. Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2019.
The new study is the first to estimate how a comprehensive list of risk factors contributes to cancer deaths and poor health at the global, regional, and national levels, across all age groups, for both sexes, and over time.
“This study illustrates that the burden of cancer remains a major public health challenge that is growing in magnitude around the world. Smoking remains the main risk factor for cancer worldwide, with other substantial contributors to the cancer burden varying,” said Christopher Murray, MD, director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington School of Medicine. and co-senior author of the study. “Our findings can help policymakers and researchers identify key risk factors that could be targeted by efforts to reduce cancer deaths and ill-health at the regional, national, and global levels,” he points.
Using the results of the GBD 2019 study, the authors investigated how 34 risk factors behavioral, metabolic, environmental, and occupational factors contributed to deaths and poor health due to 23 types of cancer in 2019. Cancer burden estimates were based on mortality and disability-adjusted life years (DALYs), a measure of years of life lost due to death and years lived with disability.
Risk factors included in the analysis were behind 4.45 million cancer deaths, which represented 44.4% of all cancer deaths in 2019; and 105 million DALYs from cancer globally for both sexes in 2019, 42.0% of all DALYs in that year.
Behavioral risk factors (such as tobacco, alcohol use, unprotected sex, and poor diet) were responsible for the vast majority of the cancer burden globally, accounting for 3.7 million deaths and 87 .8 million DALYs in 2019.
Nearly 2.88 million deaths in men (50.6% of all cancer deaths in men) could be attributed to the risk factors studied, compared to 1.58 million deaths in women (36.3% of all cancer deaths in women). The leading risk factors globally for cancer deaths and poor health for both sexes were smoking, followed by alcohol use and a high body mass index (BMI).
The leading cause of cancer death attributable to risk factors for men and women worldwide was cancer of the trachea, bronchus, and lung, accounting for 36.9%. It was followed by colon and rectal cancer (13.3%), esophageal cancer (9.7%), and stomach cancer (6.6%) in men; and cervical cancer (17.9%), colon and rectal cancer (15.8%), and breast cancer (11%) in women.
Poor health attributed to environmental and occupational, behavioral, and metabolic risk factors increased with age, peaking in the 70s according to countries’ sociodemographic index (SDI), with countries at the higher end of the spectrum tending to reach its peak at later ages.
The five regions with the highest cancer death rates due to risk factors were Central Europe (82.0 deaths per 100,000 population), East Asia (69.8 per 100,000), high-income North America (66.0 per 100,000), South Latin America (64.2 per 100,000 inhabitants) and Western Europe (63.8 per 100,000).
Between 2010 and 2019, cancer deaths due to risk factors increased by 20.4% globally, from 3.7 million to 4.45 million. Poor health from cancer increased 16.8% over the same period, from 89.9 million to 105 million DALYs.
“Policy efforts to reduce exposure to cancer risk factors at the population level are important and should be part of comprehensive cancer control strategies that also support early diagnosis and effective treatment,” said Dr. Lisa. Force, assistant professor in Health Metrics Sciences at IHME.
“The results of this study coincide with others carried out in different geographical areas (France, United Kingdom, Australia and USA) in which the proportion of cancer deaths due to modifiable risk factors would be approximately 40%“, Rafael Marcos Gragera, an epidemiologist at the Girona Epidemiology and Cancer Registry Unit of the Catalan Institute of Oncology-Oncology Master Plan, tells SMC Spain.
The expert highlights as one of the most important results of this study that, in order to evaluate the impact of cancer control measures (whether primary or secondary prevention) as well as to be able to evaluate progress in cancer care (new treatments) , are needed “quality data on both incidence and mortalityabove all, in those countries where there are no consolidated information systems«.
“Monitoring these epidemiological parameters is a fundamental tool in the strategy aimed at reducing the incidence of cancer in the population. Systematic and regular publication of results allows us not only to monitor progress in disease control, but also to identify problem areas where action is needed,” he says.
Precisely one of the limitations recognized by the study is that there are countries that do not have population-based cancer registries or consolidated mortality registries.
«It is inevitable to emphasize the importance of quality information sources that allow evaluating the impact of cancer, with special attention to Population Cancer Registries. In our country, the Spanish Network of Cancer Registries (REDECAN) works to offer quality epidemiological data on this disease, although there is still a clear need to allocate more resources to cover the entire population”, concludes Rafael Marcos Gragera.