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Obesity-related cancers increasing in younger adults

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Obesity-cancer link gaining plausibility

Cancer was long thought of as a disease of aging, but the increase in incidence of some cancers in younger age groups has driven a recent reexamination of risk factors. This study’s most striking finding is the disproportionate increase in obesity-related cancer incidence among successively younger cohorts. Coupled with the rising incidence of obesity over the same period, it provides compelling evidence of a possible causal role for obesity in the increased incidence of these cancers.

Not all obesity-related cancers, however, show this pattern of age-specific increase in incidence, which could reflect the influence of other risk factors.

The hypothesis suggested by the study’s authors is plausible but needs to be tested more directly in experimental and population-based studies.

Catherine R. Marinac, PhD, is with the department of medical oncology at the Dana-Farber Cancer Institute, Boston, and Brenda M. Birmann, ScD, is with the department of medicine at Brigham and Women’s Hospital, Boston. These comments are taken from an accompanying editorial (Lancet Public Health. 2019 Feb 4. doi: 10.1016/S2468-2667(19)30017-9). No conflicts of interest were declared.



The incidence of obesity-related cancers such as kidney and gallbladder cancer has increased significantly in young adults over the past two decades in the United States, according to an analysis of data from 25 population-based state registries in the United States.

The incidence of 6 of the 12 obesity-related cancers increased among individuals aged 25-49 years, Hyuna Sung, PhD, of the American Cancer Society, Atlanta, and her colleagues reported Feb. 4 in the Lancet Public Health.

World Obesity Federation

Among more than 14.6 million incident cases of cancer diagnosed in adults aged 25-84 years between 1995 and 2014, the greatest increase in incidence, 6.23% annually, was seen with kidney cancer among the 25- to 29-year age group. Incidence, however, also increased by at least 6.17% in those aged 30-34 years, by 5.23% in those aged 35-39 years, and by 3.88% in those aged 40-44 years.

The incidence rate for kidney cancer among individuals born around 1985 was nearly fivefold higher than in individuals born in 1950, the investigators said (Lancet Public Health. 2019 Feb 4. doi: 10.1016/S2468-2667(18)30267-6).

The analysis also showed significant increases from 1995 to 2014 in the incidence of cancer of the gallbladder among younger adults: 3.71% per year among those aged 25-29 years and 2.58% per year in those aged 30-34 years.

Similarly, the incidence of uterine corpus cancer increased in the 25- to 29-year age group by 3.34% per year and by 3.22% in the 30- to 34-year age group. The incidence of colorectal cancer increased by 2.41% among those aged 25-29 years and by 2.38% in those aged 30-34 years, Dr. Sung and her associates said.

The greatest annual increase in the incidence of multiple myeloma was seen in individuals aged 30-34 years (2.21%), but significant annual increases in incidence were seen in individuals aged 30-44 years.


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