The Big C

While cancer more commonly affects older adults, instances of early-onset cancers are increasing among those aged 14 to 49.

incidence of cases of early on-set cancer in 2010-2019

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A cancer diagnosis can happen to anyone, but cancer rates steadily increase as you age, primarily affecting older adults (over 50). However, global trends of various cancers among adults younger than 50-year-olds have been increasing in number in recent years, with 3.26 million cancer cases reported among 14- to 49-year-olds in 2019. These “early-onset cancers” are often more aggressive, with higher rates of death.

Researcher Benjamin Koh and colleagues analyzed data form the National Cancer Institute collected between 2010 and 2019 to determine the rates of cancer diagnosis and population-based characteristics for those diagnosed, including sex, race, and age. More specifically, they looked at data from 17 Surveillance, Epidemiology, and End Results (SEER) registries, a network of tumor registries from various locations throughout the U.S.

The study findings are shown in the figure above, depicting the instances of early-onset cancer diagnosis across all age groups. In 2019, breast cancer had the highest number of cases among those 14 to 49 years of age. The researchers also found gastrointestinal cancers had the fastest-growing rates of early-onset cancer. More specifically, the most common gastrointestinal cancers found were in the colon/rectum, stomach, and pancreas. The researchers note the increase in early-onset cancers occurred most often among females, but also American Indian or Alaska Native individuals and Asian or Pacific Islander individuals.

Most cancer screening guidelines call for screenings to start between the ages of 40 and 45, yet cancer instances have notably increased among 30 to 39-year-olds. The American Cancer Society recommends if you have a history of cancer within your family, you should talk to your doctor about getting screened earlier if possible.

Since the causes of this increase in early-onset cancer is unknown, Koh and colleagues suggest further research into possible factors. The authors raise the possibility that environmental sources may be associated with the growing pattern of cancer diagnosis among younger people.

Databyte via Benjamin Koh, Darren Jun Hao Tan, Cheng Han Ng, et al. Patterns in Cancer Incidence Among People Younger Than 50 Years in the US, 2010 to 2019. JAMA Network Open, 2023.