Posted on March 06, 2019
Young adults (25-49 years) in the U.S. are at greater risk for obesity-related cancers compared to those born around 1950, according to a study published in Lancet Public Health on February 1, 2019.
Investigators at the American Cancer Society and the National Cancer Institute analyzed cancer among people aged 25-84 years from 25 state cancer registries. This was the first study to investigate obesity-related cancer incidence trends using U.S. nationally-representative data among younger generations and was a continuation of the group’s previous work on colorectal cancer incidence. The investigators examined 12 obesity-related cancers and 18 additional malignancies. When grouped by birth cohort in 5-year increments, younger generations had progressively higher cancer incidence rates compared to older birth cohorts for six of the 12 obesity-related cancers, including multiple myeloma, colorectal, uterine corpus, gallbladder, kidney, and pancreatic cancers. For cancers not related to obesity, incidence in young adults increased for noncardia gastric cancer and leukemia but decreased or fluctuated for all other types.
The authors note, prevalence of overweight and obesity in the U.S. is rising. Between 1980 and 2014, children and adolescents experienced a greater than 100 percent increase in overweight/obesity prevalence while adults aged 20-74 experienced a 60 percent increase. The consequences of excess adiposity early in life on cancer risk have not been determined. However, obesity in adulthood has been linked to multiple cancer types, and early onset of obesity may exacerbate cancer risk, progression, and malignancy. More studies are needed to tease out the relationship between obesity and cancer risk at various ages, and whether increasing cancer incidence in younger ages is due to obesity or other risk factors.
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 Public Health, February 1, 2019. DOI: 10.1016/S2468-2667(18)30267-6 [Epub ahead of print]