Advances in treatment, prevention and detection behind progress, study finds
THURSDAY, Aug. 13 (HealthDay News) -- Cancer death rates are declining, especially among younger people, new research shows.
And while cancer is poised to become the number one killer in the United States, topping heart disease, that is because deaths from heart disease have decreased faster than for cancer.
"Older Americans have only experienced decreased [cancer] mortality very recently, but younger Americans have been seeing benefits for a long time so, as a result, everyone born in the last 60 years has been reaping the benefits of efforts in prevention research and treatment research and early detection research," said Dr. Eric Kort, lead author of a study appearing in the Aug. 15 issue of Cancer Research.
Kort, a pediatrics resident at Helen DeVos Children's Hospital in Grand Rapids, Mich., completed the study while a research scientist at the Van Andel Research Institute, also in Grand Rapids.
"This is pretty impressive. We have made enormous strides," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La.
Statistics on cancer rates are often adjusted for age, which skews incidence and death figures up because the population is aging and more cancer deaths occur in this older population.
"If you just take the average cancer mortality rate, by and large, that's only looking at older Americans because that's where most of the mortality is," Kort explained. "It's analogous to saying we're going to see if a train is changing directions by watching the back of the caboose and, until we see the caboose move, we're not going to say we're seeing any change."
This approach has led to criticism of gains made in the "war against cancer," although many recent studies have had good news, including an American Cancer Society report from May which found an encouraging 19.2 percent drop in cancer death rates among men from 1990 to 2005 and an 11.4 percent drop in women's cancer death rates during the same time period.
These researchers looked at mortality rates since 1955 in specific age groups, finding that U.S. cancer mortality rates have decreased overall, first in children and younger adults then more recently, in older Americans as well.
The youngest age group showed the most improvement, with a 25.9 percent decline in death rates for each successive decade, while death rates in the older age groups decreased a respectable 6.8 percent each decade. The difference likely reflects early advances in cancer treatment affecting malignancies, such as childhood leukemia, seen in younger people.
Starting in 1925, people born in later decades were less likely to die of cancer than people born in preceding decades. The death rate from cancer for people aged 30 to 59 and born between 1945 and 1954 was 29 percent lower than for people in this age group born 30 years earlier.
"The progress we've made was helpful first to younger individuals and then, as they got older, they continued to enjoy lower rates of mortality, but it's not until just recently that this became apparent in the average rates that people always talk about," Kort said. "We've made so much progress against cancer, we have transformed the mortality experience across the entire life span starting with people born 50 years ago."
This is despite the fact that incidence has remained stable or increased, except in the case of lung cancer.
"People quitting smoking has had an enormous impact. We have also made major inroads in cervical cancer death rates," Brooks said.
The authors pointed to successful chemotherapy regimens for childhood leukemias, then in lymphomas and testicular cancers of early adulthood.
Now, screening programs for breast, prostate and colon cancer are also starting to bear fruit.
"The traditional way of presenting this data is only presenting one aspect of the story of cancer mortality," Kort said. "What we're doing is filling in the rest of the picture."
The National Cancer Institute has a different set of cancer mortality data.
SOURCES: Eric Kort, M.D., pediatrics resident, Helen DeVos Children's Hospital, Grand Rapids, Mich., and former research scientist, Laboratory of Molecular Epidemiology, Van Andel Research Institute, Grand Rapids; Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Health System, Baton Rouge, La.; Aug. 15, 2009, Cancer Research
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