Investigators have found that in the majority of countries studied, the recent mortality rates for all major cancer types have decreased except for lung cancer among female patients and hepatic cancer among male patients—where increasing rates were observed in most countries, according to a novel study published by Sedeta et al in Cancer Epidemiology, Biomarkers & Prevention. The new findings demonstrated that cancer-specific mortality rates varied substantially across countries, with rates of lung and cervical cancers varying by 10-fold.

“These findings reinforce the importance of strengthening the health systems not only in resource-limited countries but also in high-income countries across the world for broad and equitable implementation of known cancer prevention and control interventions,” explained senior study author Ahmedin Jemal, DVM, PhD, Senior Vice President of the Department of Surveillance & Health Equity at the American Cancer Society. “Doing this will further mitigate the rising cancer burden and reduce cancer disparities worldwide,” he highlighted.

Study Methods and Results

In the new study, the investigators analyzed the mortality rates for the eight most prevalent types of cancers—including breast cancer, lung cancer, colorectal cancer, prostate cancer, gastric cancer, hepatic cancer, cervical cancer, and esophageal cancer—in 47 countries spanning diverse regions of the world. By examining high-quality World Health Organization mortality data and utilizing age-standardized rates, the investigators were able to unravel the distinct trends and patterns associated with each type of cancer.

Among the new findings were:

• Lung cancer mortality rates increased in female patients in 24 countries by 0.3% to 4.3% annually—with the most rapid increases observed in patients residing in Spain (4.3%), Uruguay (3.7%), and Greece (3.2%). Among the 24 countries in which lung cancer mortality rates increased among female patients, 22 of them were in Europe.
• Hepatic cancer mortality rates also increased in female patients in 15 countries by 0.9% to 4.5% annually. The most rapid increases took place the UK (4.5%), Norway (3.4%), Denmark (3.1%), and Australia (3.1%).
• Hepatic cancer mortality rates among male patients increased at overall higher rates than among female patients in 23 of the 47 countries—including in Europe, North America, and Oceania by 0.8% to 5.8% annually. The most rapid increases were observed in Ireland (5.8%), Norway (5.3%), and Malta (4.8%).
• The investigators suggested that the increase in mortality rates from hepatic cancer may largely reflect the high prevalence of Hepatitis C infections—especially in the United States—as well as nonviral etiologies such as obesity, diabetes, metabolic syndrome, non-alcoholic fatty liver disease, and heavy alcohol consumption.
• Cervical cancer mortality rates decreased in 28 of 47 countries by 0.4% to 5.2% annually, with the most rapid decreases occurring in Singapore (5.2%), Switzerland (4.7%), and the Republic of Korea (4.4%). Rates, nonetheless, increased by 0.5% to 2.5% annually in six countries across different regions of the world: Kyrgyzstan, Japan, Greece, Italy, Argentina, and Latvia.

Conclusions

The investigators stressed that understanding the current cancer burden and its trends may be crucial for monitoring progress made against cancer and identifying disparities across countries.

“There is limited published data on recent cancer mortality trends worldwide. The findings based on the up-to-date cancer mortality data may help set priorities for national and international cancer control efforts, and in so doing, reduce the marked global cancer disparities observed today,” emphasized lead study author Ephrem Sedeta, MD, MSc, a resident physician in the Department of Medicine at Brookdale University Hospital Medical Center.

The researchers concluded that implementing effective measures such as tobacco control and vaccination as well as promoting healthy lifestyles and systematic screenings may help prevent a large proportion of cancer cases globally.

Disclosure: For full disclosures of the study authors, visit aacrjournals.org.