According to a recently published report in the journal Cancer Research, cancer mortality rates have been steadily dropping over the last three decades.
“Our efforts against cancer, including prevention, early detection and better treatment, have resulted in profound gains, but thesegains are often unappreciated by the public due to the way the data are usually reported," said Eric Kort, M.D., one of the study’s authors and former research scientist at Van Andel Research Institute (VARI) in Grand Rapids, Mich.
So what’s wrong with how these “profound gains” are reported? The problem, according to Kort, is that Cancer mortality rates are typically reported as composite age-adjusted rates. And while those have slightly declined since the 1990s, they tend to emphasize the outcomes of elderly Americans, whose mortality rates are obviously much higher than those among younger patients.
To account for the potential bias of the age-adjusted rates, Kort took a different approach with his research. By stratifying cancer mortality rates by age, he found that every group of individuals has seen a drop in cancer mortality since 1925. Unsurprisingly, it was the youngest groups that saw the biggest decline at 25.9 percent, and these tend to be the individuals who are overlooked by traditional mortality statistics.
Also contributing to the public’s ignorance of the improvements in our efforts against cancer are the World Health Organization’s statistics on cancer incidence rates and mortality proportions. These rates are increasing as the years go on and are usually the only numbers that the public hears about. While they are accurate, Kort and other researchers point out that they can be misleading if not taken in context.
While both heart disease and cancer have been declining, heart disease mortality rates have been declining much more rapidly. And while it's true that cancer incidence ratescontinue to grow, the decreased mortality across all age groups shows the effect of improved screening and treatment.
In particular, “we're able to do amazing things with leukemia and lymphoma that used to be a death sentence but now we are curing many of these cancers," Richard Severson, Ph.D., a cancer epidemiologist at Wayne State University, pointed out.
Though our ability to prevent and treat cancer still has a long way to go, we’ve taken tremendous steps in the right direction and had a positive impact on cancer mortality. Hopefully with more research which accounts for often overlooked factors the public can be made aware as well.
Article: Eric J. Kort, Nigel Paneth, and George F. Vande Woude,'The Decline in U.S. Cancer Mortality in People Born since 1925',Eric J. Kort, Nigel Paneth, and George F. Vande Woude, Cancer Res 2009 69: 6500-6505. doi: 10.1158/0008-5472.CAN-09-0357