Increased incidences of myeloid leukemia and chronic lymphocytic leukemia (CLL) observed in the United States since 2011 correlated with the increased proportion of the population aged 65 and older. The findings from this study were published in Scientific Reports.
Starting in 2011, a demographic shift occurred in the US population corresponding to an acceleration in the percentage of people aged 65 years or older resulting from the high post-World War II birth rate between mid-1946 to mid-1964 — the “baby boomers”. Hence, the increasing percentage of older people in the US population has raised concerns regarding a corresponding increase in the incidence of cancer, given that the incidence of most cancers increases with age.
This study involved an analysis of cancer statistics data from the American Cancer Society on the number of cases and deaths related to both all cancers and leukemia specifically during the period covering 1998 to 2018. Particular attention was paid to changes in cancer incidence, defined as cases per 100,000 persons, since 2011, the year the oldest baby-boomers turned 65.
Surprisingly, all-cancer incidence increased by only 19% between 1998 and 2018. In contrast, the incidence of leukemia increased by 78% during this time period.
Specifically, the incidence of chronic myeloid leukemia (CML), which remained nearly constant between 1998 and 2011, was followed by a sharp 62% increase between 2011 and 2018. Moderate fluctuations in incidence of acute myeloid leukemia (AML) were observed between 1998 and 2011, but a 31% increase in AML incidence was noted from 2012 to 2018, with an overall 76% increase in the incidence of AML from 1998 to 2018.
“These data suggested an important trend of rapid increase of myeloid leukemia after 2011,” the study authors commented.
Furthermore, the incidence of chronic lymphocytic leukemia (CLL) was reported to have risen by 146% between 1998 and 2018, with increases of 52% from 2006 to 2007 and 29% from 2015 to 2016. Although the incidence of acute lymphocytic leukemia (ALL) rose by 30% from 2006 to 2007, it was shown to remain relatively constant from 2007 to 2018.
Regarding recent changes in the incidence of all cancer, the study authors stated that “although the impact of aging ‘baby boomers’ on cancer may not be fully realized until 2030 when all ‘baby boomers’ turn 65, it is a bit of a relief for now that the previously anticipated high rise of cancer incidences has not materialized.”
The study authors concluded that “before all ‘baby boomers’ turn 65 in the year 2030, the US aging population will continue to grow, and leukemia incidences are expected to rise further. Therefore, this study will raise public awareness about these important trends of leukemia in the years to come, and provoke us to rethink cancer prevention strategies to reduce the incidences of leukemia and other cancers in aging Americans.”