Cancer death rates have fallen dramatically in the United States, but take obesity into account, as did researchers at the Gillings School of Global Public Health at the University of North Carolina, and the table changes.
In a study published May 10 in JAMA network open, researchers have shown that obesity-related cancer deaths are improving, but at a slower rate.
Based on mortality data from 50 million people, deaths from cancers not associated with obesity – that is, lung cancer and skin cancer, among others – are declining to a rate almost three times faster than obesity-related cancers, such as stomach, colorectal cancer, uterine, thyroid and postmenopausal breast cancer.
“These are cancers where we could see even greater improvements in mortality with creative and practical tools to fight obesity,” said Hazel B. Nichols, lead author of the study, associate professor in the department. of Epidemiology from the UNC Gillings School of Global Public Health.
Most Americans weigh more than recommended, and being overweight or obese puts them at risk for certain cancers.
According to the United States Centers for Disease Control and Prevention, being overweight can cause changes in the body that contribute to cancer, such as long-lasting inflammation and higher than normal insulin and hormone levels that can fuel cell growth.
Cancer death rates are one of the best metrics researchers use to track progress in cancer control.
The study’s authors investigated whether generalized obesity could hold back progress against cancer in the same way as it did for heart disease. Improvements in heart disease mortality slowed after 2011, and obesity may have contributed to the deceleration.
“What was puzzling was that we didn’t see the same pattern of slower improvements looking at cancer as a whole – which is surprising because obesity contributes to both cancer risk and cancer. risk of heart disease, ”said Nichols, who studies cancer trends to improve the decision. -provide cancer care. “When we focused on the differences between obesity-related cancers and non-obesity-related cancers, we found that the improvements for obesity cancers were not as impressive – consistent with the diagram of heart disease. “
For example, the study showed that in 2011, 110 out of 100,000 people died from cancers unrelated to obesity. In 2018, the death rate from these cancers fell to 93.8 deaths per 100,000 people, an annual decrease of 2.29%.
Over the same period, the decline in obesity-related cancers has been much slower, dropping from 58.4 to 54.9 deaths per 100,000 people, or about a third of the rate – at 0.83% – cancers unrelated to obesity.
Additionally, obesity may contribute to more cancer deaths in the U.S. Non-obesity cancers accounted for 66.8% of cancer deaths in 1999, declining to 62.6% in 2018, according to the ‘study.
According to the American Cancer Society, the decline in cancer deaths is due to fewer people smoking, as well as better screening and treatment.
But the findings of UNC researchers, including Christy Leigh Avery, associate professor at the Gillings School of Global Public Health specializing in cardiovascular epidemiology and member of the Carolina Population Center and Annie Green Howard, associate professor of biostatistics at Gillings and colleague at Carolina Popular Center, enhances the effect of obesity on cancer.
“Obesity is a risk factor for many types of cancer, but not all,” Nichols said. “We must make maintaining a healthy weight an achievable goal for all in terms of safe public spaces, availability and affordability of nutritious food and other structural factors. The good news is that if we are able to make these changes as a society, we can improve the health of a nation. “
The National Institutes of Health funded the study.