The authors call for more personalized screening protocols to find cancer earlier in younger adults, as well as public health efforts to address obesity.
Another analysis of US cancer data published this week shows that cancers related to obesity are showing up in younger adults, and the researchers say the impact on Medicare and Medicaid in coming decades will be severe unless screening programs can better pinpoint who is likely to develop the disease.
Siran Koroukian, PhD; Weichuan Dong, MA; and Nathan A. Berger, MD, examined records from more than 2.6 million obesity-related cancer cases and more than 3.4 million non—obesity-related cancer cases in the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2016, looking not only at the age distribution but also how obesity-related and non–obesity-related cancers were distributed by race and gender during that period.1
Although other studies in recent years have noted the rise in the rate of obesity-related cancers among younger adults, this is the first that also found a concurrent decrease in the rate of new cancer cases among patients age 65 and older. “It is possible that changes in cancer surveillance over time have improved early cancer detection,” the investigators wrote.
In other words, the good news is that the screening protocols in Medicare are working. The bad news is that a different, more personalized screening approach is needed for younger adults, especially those age 50 to 64. In this age group, obesity-related cancers in particular are rising.
The latest study adds to concerns that the US obesity epidemic is thwarting other gains in preventing and curing cancer. Overall, cancer survival rates have improved for the past quarter century, aided by declining smoking rates.2 In 2017, CDC published data that showed 40% of all cancer diagnoses were associated with 13 types of cancer associated with obesity: adenocarcinoma of the esophagus, cancers of the gastric cardia, colon and rectum, liver, gallbladder, and pancreas; and cancers of the ovaries, the uterus, the kidney, and the thyroid.3 A February 2019 study in The Lancet by the American Cancer Society and the National Cancer Institute found that cancer incidence rose for 6 of 12 obesity-related cancers between 1995 and 2014 in adults aged 25 to 49, with steeper increases in younger generations.4
For this new study, researchers defined obesity-related cancers as those of the colon and rectum, female breast, uterus, gallbladder and other biliary, esophagus, stomach, liver, pancreas, ovary, kidney and renal pelvis, thyroid, and myeloma.1
The investigators found the following:
What types of cancer are were on the rise? While there was variation by age, race, and gender, liver and thyroid cancers rose sharply among many groups, the data show. Liver cancer is one of the fastest-rising cancer diagnoses in the United States, according to CDC.2
The study found:
“The shift of the cancer burden to younger age groups has important public health, research, and policy implications,” the investigators wrote. When cancer is diagnosed in younger adults, the disease may already be more advanced and more aggressive.
Also, the authors noted that if more young adults develop obesity-related cancers in their 40s and 50s, this will mean more cancer survivors will join the ranks of Medicare, having endured the physical, financial, and emotional hardships of living with the disease. Due to the expense of today’s therapies and the cost-sharing designs of some health plans, many may also qualify for Medicaid.
“Together, these findings suggest an increasing cancer burden on Medicare and Medicaid programs in the future,” they wrote.
Reducing obesity may be the best solution, but short of that, the investigators recommend improving screening programs through better risk stratification to catch cancer earlier or prevent it among younger adults. “The findings have important public health implications and suggest that interventions to reduce obesity and to implement individualized screening programs are needed,” the authors concluded.