Successively younger generations are facing increasing burdens of obesity-related cancers such as kidney cancer.
During 1995 to 2014, nearly 15 million cases of the 30 most common types of cancer occurred in the United States, Ahmedin Jemal, DVM, PhD, of the American Cancer Society, and colleagues reported in the Lancet Public Health. Incidences of 6 of the 12 established obesity-related cancers increased steeply in adults 25 to 49 years old: colorectal, uterine corpus, gallbladder, kidney, and pancreatic cancer and multiple myeloma. In this younger population, obesity-related cancer diagnoses increased at an annual rate of 1.4% for multiple myeloma up to 6.2% for kidney cancer.
For middle-aged adults (aged 45 to 49 years), annual rates increased from 0.37% for uterine corpus cancer to 3% for kidney cancer. Millennials born in 1985 had 5 times greater risk for kidney cancer than baby boomers born around 1950. In contrast, of the 18 cancers not tied to obesity that commonly occur in those younger than 50 years, 8 declined in incidence, 8 held steady, and only gastric non-cardia cancer and leukemia cases increased.
Investigators culled the incidence data from 25 state cancer registries covering 67% of the US population, using the Cancer in North America database. Currently, overall cancer incidence remains highest in older adults.
“Our findings expose a recent change that could serve as a warning of an increased burden of obesity-related cancers to come in older adults,” Dr Jemal commented in a journal news release. “Most cancers occur in older adults, which means that as the young people in our study age, the burden of obesity-related cancer cases and deaths are likely to increase even more. On the eve of World Cancer Day, it’s timely to consider what can be done to avert the impending rise.”
Rising obesity may be among the factors driving the increase. “In concert with excess bodyweight, obesity-related health conditions and lifestyle factors can contribute to the increasing burden of obesity-related cancers in young adults, which include diabetes, gallstones, inflammatory bowel disease, and poor diet,” according to the study authors. Excess weight may be responsible for a full third of kidney cancers.
Sung H, Siegel RL, Rosenberg PS, Jemal A. Emerging cancer trends among young adults in the USA: analysis of a population-based cancer registry. Lancet Pub Health. DOI: 10.1016/S2468-2667(18)30267-6
Marinac CR, Birmann BM. Rising cancer incidence in younger adults: is obesity to blame? Lancet Pub Health. DOI:10.1016/S2468-2667(19)30017-9
Obesity-related cancers increasing in young US adults. Lancet Public Health; Feb 4, 2019 (news release).