NIH researchers report rising rates of several early-onset cancers in the U.S., prompting calls for more research into the causes and consequences of these alarming trends.
Although
cancer incidence rates are rising, overall cancer deaths among young people
have not increased.
Researchers at
the National Institutes of Health (NIH) have uncovered some important trends
in cancer cases across the United States. Between 2010 and 2019, they found
that 14 types of cancer became more common among people under the age of 50.
Among these were several well-known types, including breast cancer and
colorectal cancer. Interestingly, nine of the rising cancer types also showed
increases in some people over 50.
At the same time, the good news is that the incidence
of 19 other cancers, such as lung cancer and prostate cancer, actually went
down in younger adults. Because of these offsetting trends, the overall rate of
cancer diagnoses stayed steady across all age groups. Even more encouraging,
the overall cancer death rate did not increase during this period.
“This study provides a starting point for
understanding which cancers are increasing among individuals under age 50,”
said lead investigator Meredith Shiels, Ph.D., of NIH’s National Cancer
Institute. “The causes of these increases are likely to be cancer specific,
including cancer risk factors becoming more common at younger ages, changes in
cancer screening or detection, and updates to clinical diagnosis or coding of
cancers.”
The study was recently published in Cancer Discovery.
Study Design and
Scope
Researchers examined incidence and mortality trends
for 33 cancer types, including incidence data for 2010-2019 from CDC’s United
States Cancer Statistics database, which includes cancer registry data that
represent the entire U.S. population, and mortality data for 2010-2022 from
national death certificate data. Data were analyzed in six age groups: three
early-onset (15-29 years, 20-39 years, and 40-49 years) and three older-onset
(50-59 years, 60-69 years, and 70-79 years).
Incidence of 14 of the 33 cancer types increased in at
least one of the younger age groups. Incidence of nine of these 14 types also
increased in at least one of the older age groups: female breast, colorectal,
kidney, testicular, uterine, pancreatic, and three types of lymphoma. Although
death rates did not increase in early-onset age groups for most of these
cancers, researchers did observe concerning increases in rates of colorectal
and uterine cancers deaths at younger ages.
Only five cancer
types increased in incidence among one of the younger age groups but not among
any of the older age groups: melanoma, cervical cancer, stomach cancer,
myeloma, and cancers of the bones and joints.
Understanding
the Numbers
To understand the magnitude of the increases in terms
of absolute numbers, the researchers estimated how many additional people were
diagnosed with early-onset cancers in 2019 compared with expected diagnoses
based on rates in 2010. The largest absolute increases were seen for female
breast cancer, with about 4,800 additional cases in 2019, followed by
colorectal (2,100), kidney (1,800), uterine (1,200), and pancreatic cancers
(500). Female breast, colorectal, kidney, and uterine cancers contributed to
more than 80% of the additional early-onset cancers in 2019.
The researchers speculated that risk factors such as
increasing obesity may have contributed to some of the increases in early-onset
cancer incidence in recent years. Changes in cancer screening guidelines,
advances in imaging technologies, and increased surveillance of high-risk
individuals may also have led to earlier cancer diagnoses, potentially
contributing to rising rates among younger age groups.
To more fully understand and address these increasing rates, the authors said that future studies should examine trends in early-onset cancers across demographics and geography in the U.S. and internationally. Additional research is also needed to better understand the risk factors that are particularly relevant to younger people.
No comments:
Post a Comment