Being overweight or obese is associated with an increased risk of various types of cancer, according to the American Cancer Society (ACS). These obesity-related cancers are now found to be on the rise among young people in the United States. What’s more, rates are steeply increasing in progressively younger ages and successively younger generations, suggest new findings published in The Lancet Public Health, reports ACS.

Using the Cancer in North America database provided by the North American Association of Central Cancer Registries, scientists examined over 20 years of incidence data between 1995 and 2014 for 30 cancers in 25 states. The analysis included 12 cancers linked to obesity and 18 cancers unrelated to obesity. 

Findings showed that incidence increased in young adults and successively younger birth cohorts in a stepwise manner for six of the 12 obesity-related cancers: colorectal, endometrial, gallbladder, kidney, multiple myeloma and pancreatic cancers. 

The risk of colorectal, endometrial, pancreas and gallbladder cancers in millennials was nearly double the rate of baby boomers when they were that age. But research also showed that rates in successive younger birth cohorts declined or stabilized in all but two of 18 non-obesity-related cancers.

According to Ahmedin Jemal, PhD, scientific vice president of surveillance and health services at the American Cancer Society and senior/corresponding author of the paper, these findings will have significant public health implications.

“Given the large increase in the prevalence of overweight and obesity among young people and increasing risks of obesity-related cancers in contemporary birth cohorts, the future burden of these cancers could worsen as younger cohorts age, potentially halting or reversing the progress achieved in reducing cancer mortality over the past several decades,” said Jemal. “Cancer trends in young adults often serve as a sentinel for the future disease burden in older adults, among whom most cancer occurs.

The American Society of Clinical Oncology’s (ASCO) president, Monica M. Bertagnolli, MD, FACS, FASO, also released a statement on the recent findings.

“Rates of obesity-related cancers are rising most sharply among young adults, but this study should serve as a wake-up call to all Americans—young and old alike—that obesity is linked to an increased risk of common cancers,” Bertagnolli said. “If current trends continue, it is estimated that obesity will lead to more than 500,000 additional cases of cancer each year in the United States by 2030.

Experts are calling for health care providers and policymakers to develop groundbreaking approaches to mitigate morbidity and premature death associated with obesity-related diseases.   

Click here to learn how adolescent obesity may increase pancreatic cancer risk.