Rafael Marcos Gragera
Epidemiologist at the Catalan Institute of Oncology and professor of medicine at the University of Girona
Researchers led by Carlo La Vecchia, professor of Medical Statistics and Epidemiology at the University of Milan (Italy), predict that the greatest increase in colon cancer mortality rates will be in younger people.
In the study presented on mortality predictions in Europe for 2024, the data analyse official mortality in European countries. The methodology is correct. Such studies are useful and necessary to assess the long-term control of chronic diseases.
The published data on mortality trends are consistent with the data presented for incidence trends. Both epidemiological indicators show a similar direction, indicating an increase in colorectal cancer incidence and mortality in young people.
There are possible explanations for this increase in colorectal cancer incidence and mortality in young people. Risk factors that have undergone changes in recent decades and that may affect young people include mainly environmental factors, such as obesity in adolescence, prolonged sedentary behaviour and dietary factors that are now increasingly consumed during childhood and adolescence, such as sugary drinks, red and processed meats, and Western diets.
Unfortunately, observational studies offer only a superficial insight into our understanding of the biology of colorectal cancers in young people. Robust epidemiological studies with validated dietary and lifestyle data, collected prospectively and repeatedly over a lifetime (the 'exposome'), are crucial. These studies are of vital importance to accurately measure exposures, their potential confounders and the time and latency window of cancer related to the risk factors involved.
Although Europe shows a decrease in mortality rates for most types of cancer in projections to 2024, unfortunately, this trend is not reflected for pancreatic cancer. Mortality from pancreatic cancer continues to increase in the European population, both in men and women, and is now the fourth leading cause of cancer-related deaths. This type of cancer continues to be diagnosed in advanced stages, which contributes to its unfavourable prognosis, as evidenced by the mortality data.
[As the author points out, the covid-19 pandemic had a considerable impact on the number of cancer diagnoses in several countries during the year 2020, as well as on the mortality of these patients. Due to the pandemic, cancer screening programmes were affected to varying degrees, which probably resulted in fewer diagnoses of colorectal, breast and cervical cancer than expected in 2020, and this will consequently have affected mortality and should be taken into account when interpreting prediction results with mortality data from years prior to the pandemic.