Pancreatic cancer is killing more people than it did in the 1990s, but colorectal cancer deaths are on the decline, a global study has found.
The analysis was part of the Global Burden of Disease Study published in The Lancet Gastroenterology & Hepatology as two separate papers in October.
Since 1990, the number of deaths from pancreatic cancer has increased 2.3 times, with 441,000 deaths in 2017, according to the study.
The incidence rate of pancreatic cancer also increased over the 27-year study period, with 448,000 people having a diagnosis in 2017.
Pancreatic cancer is one of the most lethal cancers, with a five-year survival rate of just 5%, so there are almost as many deaths as there are cases each year.
The most important risk factor for pancreatic cancer was age, and the number of deaths from pancreatic cancer would probably continue to rise as the population aged, the authors said.
The incidence rate of pancreatic cancer varied greatly across the globe, with higher-income countries being worst affected.
“Although the causes of pancreatic cancer are still insufficiently understood, certain risk factors have been identified, such as smoking, obesity, and diabetes,” the authors said.
“These risk factors probably explain some of the national variation.”
The study estimated that 21% of pancreatic cancer deaths were tied to tobacco, 9% were related to type 2 diabetes and 6% were linked to obesity.
The news around colorectal cancer was more heartening, with death rates declining worldwide.
Over the study period, the age-standardised death rate from colorectal cancer decreased 13.5% to 896,000 deaths in 2017.
One of the reasons for the decrease in death rates was the active screening programs in countries like Australia, said Professor Tim Price, the chair of the colorectal cancer guidelines revision working party at Cancer Council Australia and a medical oncologist at The Queen Elizabeth Hospital in Adelaide.
“We pick up polyps before they become cancer, for example, and also pick up earlier bowel cancers and that is reflected in the improved survival,” he said.
“So, earlier diagnosis will play a big part. There are also much better drug treatments for more advanced disease compared to back in 1995.
“We have a number of different chemotherapy drugs, for example, compared to 20 years ago, so we can control even more advanced disease for much longer.”
The incidence of colorectal cancer has increased 9.5% since 1990 around the world, according to the study.
“One potential explanation for this global increase in age-standardised incidence is that the introduction of screening tests might have led to increased detection and thus increased incidence, but this increase might be short-lived because of the removal of precancerous polyps during colonoscopies,” the authors said.