Key clinical point: The incidence of obesity-related cancers has increased in younger adults.
Major finding: The incidence of kidney cancer has increased by more than 6% per year in younger adults since 1995.
Study details: Analysis of data from 14,672,409 cases of cancer diagnosed between 1995 and 2014.
Disclosures: The study was funded by the American Cancer Society and the National Cancer Institute. No conflicts of interest were declared.
Sung H et al. Lancet Public Health. 2019 Feb 4.
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.