Recent trends also highlight global disparities in cancer burden – ScienceDaily
Cancer deaths jumped to 10 million and new cases soared to more than 23 million worldwide in 2019, according to a new scientific study from the Institute for Health Metrics and Evaluation (IHME) at the Faculty of Medicine of the United States of America. ‘University of Washington.
At the start of the decade in 2010, the total number of cancer deaths stood at 8.29 million worldwide and new cancer cases stood at 18.7 million; counts at the end of the decade in 2019 represent increases of 20.9% and 26.3%, respectively.
The article was published on December 30, 2021 in JAMA Oncology, and is part of the 2019 Global Burden of Disease, Injury and Risk Factor Study (GBD 2019).
The researchers estimated the global cancer burden and trends for 204 countries and territories. They found that cancer was second behind cardiovascular disease in terms of number of deaths, disability-adjusted life years (DALYs) and years of life lost (YLL) among 22 disease groups and injuries worldwide in 2019. In the total cancer burden, the top five causes of cancer-related DALY for both sexes combined were cancer of the trachea, bronchus and lung (TBL); colon and rectal cancer; stomach cancer; breast cancer; and liver cancer. TBL cancer was the leading cause of cancer death in 119 countries and territories for men and 27 countries and territories for women.
Although the absolute cancer burden increased in both deaths and new cases from 2010 to 2019, global age-standardized death and incidence rates decreased by 5.9% and 1.1% , respectively. From a country perspective, the age-standardized death rate declined in 131 countries and territories and the age-standardized incidence rate decreased in 75 countries and territories. The small percentage of declines globally is promising, but researchers warn that there could be setbacks in cancer care and outcomes due to COVID-19. The effects of the pandemic on morbidity, mortality, and cancer prevention and control efforts were not taken into account in this GBD study, which analyzed the global cancer burden through 2019.
The authors also analyzed the burden of cancer based on the Sociodemographic Index (SDI), a composite measure of per capita income, the average number of years of schooling, and the total fertility rate for people of under 25.
While the global trend in age-standardized death and incidence rates is encouraging, the reduction in rates appears to be due to higher SDI locations. For mortality, the age-standardized rates declined in the middle, middle-high, and high quintiles and increased in the bottom and bottom-middle quintiles. Likewise, for incidence, age-standardized rates declined in the top-middle and top quintiles – with the largest decrease in the high SDI quintile – while increasing in the bottom, bottom-middle, and middle quintiles. .
“It is crucial to ensure that global progress against the cancer burden is equitable,” said Dr Jonathan Kocarnik, lead author of the study and researcher at IHME. “This will require efforts to reduce disparities in cancer prevention, treatment and survival, and the incorporation of local needs and knowledge into tailored national cancer plans.”
Dr Kocarnik and his co-authors suggested that larger increases in the lower quintiles of SDI likely reflect ongoing epidemiological transitions, demographic shifts, and disparities in cancer prevention, care, and control. Even without taking into account the COVID-19 pandemic, the absolute burden of cancer is already increasing dramatically around the world.
Some additional findings from the study:
- Breast cancer was the leading cause of cancer-related deaths among women worldwide, including in 119 countries.
- Globally, 96.9% of cancer-related DALYs, which are the sum of YLL and years lived with a disability, can be attributed to YLL or premature death.
- Of the 22 disease and injury groups in the GBD study, total cancer is the leading cause of DALY for the high SDI quintile and among the top five causes of DALY for three of the remaining four SDI quintiles.