CLEVELAND, Ohio — Cancers associated with obesity are striking people at a younger age, especially those ages 50 to 64, a new study by Case Western Reserve University faculty suggests. Some people younger than 50 are affected as well.
Some of the greatest increases in cancer rates were for liver and thyroid cancers for both men and women of all races. Specific types of obesity-associated cancers were dramatically higher in Hispanic men and women, the study suggests.
The long-term impact of these trends could include lower workplace productivity and an increased strain on the country’s health care system, especially Medicare, the study’s authors said.
Obesity-associated cancers include colorectal cancer; postmenopausal breast cancer; cancer of the uterus, ovaries, liver, esophagus, pancreas, kidney or thyroid; and multiple myeloma.
What is the correlation between obesity and cancer? “That’s the million-dollar question,” said study co-author Dr. Nathan Berger, CWRU professor of medicine, biochemistry and oncology.
In most cases, being overweight doesn’t cause cancer, but accelerates it, Berger said.
The key may lie in the ways that obesity affects the body. Being overweight leads to hormonal changes and changes in intestinal bacteria; both of these may stimulate cancer cells to grow, Berger said.
Other researchers across the country are also studying obesity and health by focusing on the brain.
A recent long-term study of brain development and children’s health, led by the University of Vermont, raised questions about obesity and brain function. If confirmed, these findings could help researchers look inside the brain for ways to fight obesity, the Associated Press reported.
The new study, published in JAMA Pediatrics, raised the possibility that inflammation affecting weight, brain structure and function might begin in childhood. The study involved more than 3,000 American children ages 9 and 10; almost 1 in 3 were overweight or obese, which matches national statistics.
The CWRU study looked at 13 obesity-associated cancers, and found increasing numbers of cases and worse outcomes for obese people, Berger said. Cancer rates are normally higher in people older than 65, and the average age of diagnosis is 67.
The CWRU study found that obesity-associated cancers increased 200% in Hispanic men ages 50 to 64. Some of the greatest increases were in kidney and uterine cancers among Hispanic women.
The study, titled “Changes in Age Distribution of Obesity-Associated Cancers,” was published in the journal JAMA Network Open. It was authored by Berger, Siran Koroukian and Weichuan Dong.
Koroukian is an associate professor with the CWRU School of Medicine and a member of the Case Comprehensive Cancer Center. Dong is a health services research analyst at CWRU and a PhD candidate in geography at Kent State University.
The researchers looked at data from more than 6 million cancer cases from the Surveillance Epidemiology and End Results, or SEER, database that is administered by the National Institutes of Health’s National Cancer Institute. The data came from patients diagnosed between 2000 and 2016, but did not follow individual patients’ progress during that time period.
It isn’t known whether obese people who lose weight eliminate or reduce their risk of developing obesity-associated cancers, Berger said. However, it is important to maintain a healthy weight at all stages of life.
Next, Berger and his fellow researchers would like to examine the SEER data for clues to what is causing the acceleration of obesity-associated cancers, and ways to disrupt the link between excess weight and cancer.
