Colon and rectal cancer mortality rates are projected to decrease by the year 2035 in most countries across the globe except some countries in Latin American and the Caribbean, according to results from a trend-based prediction study on data from a WHO mortality database.
The study results, however, also indicated that rectal cancer mortality is predicted to rise substantially in some countries including the United States and Australia.
“It is known that future planning is an integral part of cancer control programs,” Marzieh Araghi, PhD, MPH, a postdoctoral scientist in the section of cancer surveillance at International Agency for Cancer Research, and lead author of the study, told Healio Gastroenterology and Liver Disease. “As a cancer epidemiology researcher, I was interested in quantifying the magnitude of the problem in terms of number of future deaths from colon and rectal cancer and the extent to which trends that have changed in the past and how this might affect the future.”
Araghi and colleagues obtained data from the latest update of the WHO mortality database to identify deaths from malignant neoplasms of the colon and rectum across the world.
The researchers only included countries if they provided at least 25 years of mortality data and more than 50 deaths from either colon or rectal cancer was reported in the most recent available statistics.
The researchers then used a software package, known as NORDPRED, to predict the number of deaths and mortality rates of colon and rectal cancer by country, sex and age.
Colon cancer mortality rates were predicted to decrease in 32 of the 42 countries included in the evaluation. The largest projected mortality declines are expected to occur in Australia (50%), Ireland (49.2%) and Czech Republic (37.8).
Although rectal cancer mortality rates are expected to decrease in 25 of the 42 countries that were studied, the countries with the most likely substantial increases include Costa Rica (73.6%), Australia (59.2) and the United States (27.8%).
While most mortality rates are expected to decrease, the total number of deaths from colon and rectal cancer across all included countries is predicted to increase by 60% and 71.5%, respectively, when comparing between 2013 and the projection for 2035.
“Death rates for both colon and rectal cancer are expected to drop globally but the total number of deaths is expected to rise, due to population growth and aging,” she said. “The predicted rise in rectal cancer in Australia, along with Canada and the United States is worrisome and the underlying mechanisms warrant further research.”
Araghi acknowledged that more research is needed to identify the causes of these increases, but she did offer some possible suggestions.
“While the true underlying causes of the rise in colorectal cancer mortality needs to be identified, possible explanations include changes in the prevalence of risk factors such as increasing body weight and lower physical activity,” she said. “The role of primary health care in the prevention of cancer through designing and implementing health interventions to help individuals to adopt a healthy lifestyle is pretty crucial.”
Araghi noted that there was a limitation with the study.
“Trend-based predictions should be interpreted with caution since they are by definition based on the assumption that trends observed in the past will continue into the future,” she said. – by Ryan McDonald
Disclosures: The researchers report no relevant financial disclosures.