Thyroid, Kidney Cancer on Rise Among Adolescents and Young Adults

Thyroid cancer, as well as cancers related to obesity—such as kidney cancer—stood out among cancers that saw a rise among adolescents and young adults (AYAs) over the past decade, according to data reported by the American Cancer Society (ACS).

The overall cancer story is positive—cancer mortality has been steadily dropping for more than 25 years. But due to obesity, cancer cases are increasing among those aged 15 to 39 years; the authors of the ACS study project there will be 89,500 new cancer cases in 2020, along with 9270 cancer deaths in this age group.

Their analysis, published in CA: A Cancer Journal for Clinicians, is based on data from 2007 through 2016. The authors examined the group by type of cancer and by age group, looking at those aged 15-19, 20-29, and 30-39 years; the authors also looked at the patients’ age, gender, and race or ethnicity.

Diagnoses of thyroid cancer have been increasing across all age groups, and rose 3% annually among those 20 to 39 years and 4% for those 15 to 19 years. Although it is believed that much of the increase is due to better screening, epidemiologists agree this doesn’t fully explain the increase and environmental factors are likely in play.

Kidney cancer rose 3% per year across all 3 AYA age groups, with other obesity-related cancers increasing during the study period as well: among those 20 to 39 years, uterine corpus rose 3%, and colorectum rose 0.9% to 1.5%. The rise among younger groups is in contrast with kidney cancer rates leveling off overall, following a period of rising rates that were attributed to increased detection, according to ACS. Workplace exposures and taking too much acetaminophen have been blamed for the increase as well.

However, the authors warn, more research is needed to fully understand the increase. “For example, the increase in kidney cancer, which is the most rapidly increasing cancer across all AYA age groups, is largest for high-grade, aggressive tumors and renal cell carcinoma; renal pelvic cancer rates have not similarly increased, as would be expected from increased detection,” they wrote.

The worrisome news in obesity-related cancers is offset by declining rates of melanoma in those aged 15 to 29 years (4% to 6% annually), although rates were stable among those aged 30 to 39. In recent years, public health awareness campaigns have tried to educate target groups, especially young women, about the need for sun protection to avoid cancer. Most young adults today had parents who were taught to protect their children with sunscreen.

Other highlights from the report:

• Overall cancer mortality declined from 2008 through 2017 by 1% annually across all age and gender groups, except for women aged 30 to 39 years, among whom rates were stable due to flattening of declines in breast cancer.
• Five-year survival in AYAs is similar across age groups for all cancers, ranging from 83% to 86%, but can vary for some cancers, such as 74% for those 15 to 19 years of age with acute lymphocytic leukemia vs 51% for those 30-39 years with that condition.

The authors say the best way to make headway in mortality rates in AYA cancers is to ensure more equitable access to health care, increase clinical trial enrollment, expand research, and improve awareness among clinicians for early signs of cancer in younger populations.

Reference

Miller KD, Fidler-Benaoudia M, Keegan TH, Hipp HS, Jemal A, Siegel RL. Cancer statistics for adolescents and young adults. 2020: CA: Cancer J Clin. Published online September 17, 2020. doi.org/10.3322/caac.21637​