‘Incidence does not equal mortality’: Researchers question rise in early-onset cancer incidence

Three researchers have cautioned against interpreting the recent rise of early-onset cancer incidence as a “true increase in cancer occurrence.” They shared their concerns in an article published Sept. 29 in JAMA Internal Medicine. 

A recent American Cancer Society study found that the surge of local- or early-stage colorectal cancer diagnoses in adults younger than 50 was likely tied to increased screening uptake after the American Cancer Society and the U.S. Preventive Services Task Force lowered their recommended screening age from 50 to 45 in 2018 and 2021, respectively. 

Here are three things to know from the article:

1. The eight cancers with the fasting-rising incidence among younger adults in the U.S. are thyroid, anus, kidney, small intestine, colorectum, endometrium, pancreas and myeloma.
   
   Though incidence has risen for those cancers, mortality has remained flat with only a “slight rise” found in colorectal and endometrial cancer, and stable or declining mortality for the others.
   
   
2. The researchers propose the rising incidence can be attributed to an increase in cancer detection and overdiagnosis.
   
   Overinterpreting the increasing incidence of early-onset cancers may “perpetuate the idea that something in our environment or lifestyle is triggering more cancers, when physicians may simply be detecting more cases that were always present,” the researchers wrote.
   
   
3. “The rise in early-onset cancer appears to be less an epidemic of disease and more an epidemic of diagnosis,” the researchers wrote. “Mortality of all cancers combined in adults younger than 50 years has decreased by nearly half since the 1990s. […] Deaths of cancer comprise only 10% of all deaths in adults younger than 50 years. Suicides and unintentional deaths outnumber cancer deaths more than 4-fold, and both are rising.”
   

Read the full article here.