An analysis released Monday by the American Cancer Society (ACS) reveals that obesity-linked cancers are on the increase among young adults in the USA, a trend which could stifle the progress made in reducing cancer mortality over the last few decades.
The society says a steep increase in the prevalence of obesity over the last 40 years may have increased the risk among younger people and that the problem could be a set back to the recent progress made in addressing cancer.
"Although the obesity epidemic is a quite plausible scenario, we need more knowledge to explain the trends with additional known and unknown cancer risk factors that may have contributed to these trends", she says. This may be related, partly, to the rising obesity epidemic found around the world.
"Although the absolute risk of these cancers is small in younger adults, these findings have important public health implications", Ahmedin, senior author of the paper, said in a statement. He points out that five of the six cancers on the rise in younger adults - colorectal, uterine, gallbladder, kidney and pancreatic cancer - are treated surgically.
A sharp increase in obesity-linked cancers among young adults in the United States could foreshadow a reversal in the overall decline in cancer mortality, researchers warned Monday. The numbers suggest that millennials have roughly twice the risk of developing these cancers as baby boomers did at the same age.
Building on earlier research suggesting a link between obesity and more frequent colon cancers in young adults, Jamel and colleagues analysed all cancer cases from 1995 to 2015 in 25 U.S. states home to 67 percent of the population. British obesity rates are not far behind the US.
"Similarly, the annual percent change by age was largest in individuals aged 25-29 years for cancers of the kidney, gallbladder, corpus uteri, and colorectum, and in individuals aged 30-34 years for multiple myeloma", the authors wrote in the study. For example, diabetes, gallstones, inflammatory bowel disease, and poor diet can all increase the burden of cancer.
The younger the age bracket, the more quickly these cancers gained ground, they reported in The Lancet, the medical journal.
For example, the average annual rate for pancreatic cancer was about 1 percent in those aged 40 to 84, 1.3 percent in those aged 35 to 39, almost 3 percent in those aged 30 to 34, and 4 percent among those aged 25 to 29. If trends continue as projected carrying excess weight could cause even more cases of cancer in women than smoking within 25 years. Not everyone who gets these cancers is overweight either, and not everyone who is obese will necessarily get these cancers.
What this research shows, Berger said, is an association between cancer and obesity in younger and younger ages.
"Obesity during childhood actually is a major predictor of adult obesity", Chang said, "I think it highlights the importance of reducing the rates of obesity through better diet, better and more exercise".