While much of the health system and the world are, understandably, laser focused on the Covid-19 pandemic, it is all too easy to discount other health issues that must be addressed. In a recent study of cancer trends among adolescents and young adults in the US, researchers reported a stunning thirty percent increase in cancer diagnoses among individuals fifteen to thirty-nine years old between 1973 and 2015.
Recently, there has been an increased awareness that adolescents and young adults are a distinct population when it comes to cancer. A cancer diagnosis at this pivotal stage in life where young peoples’ independence is increasing, careers are beginning, and new relationships are forming can be particularly destabilizing. In addition, adolescents and young adults are often less financially stable than older adults and have the lowest rates of health insurance coverage.
There is also evidence that tumors in this age group are different on a molecular level from the tumors found in either children or older adults. While survival rates are higher among adolescents and young adults with cancer compared to older adults, cancer patients in younger age groups have a higher risk of developing long-term effects stemming from their cancer such as infertility, cardiovascular disease, sexual dysfunction, and cancer later in life. Because of young peoples’ unique experience with cancer, there has been more research trying to understand the rates and causes of cancers in this age group and to determine effective treatment options.
This new study looking at trends in cancer diagnoses between 1973 and 2015 in adolescents and young adults provides important new insights on the long-term characteristics of cancers in this population. Researchers collected data on age at diagnosis, sex, race, type of cancer, and survival from almost 500,000 of the adolescents and young adults diagnosed with cancer between 1973 and 2015 from a National Cancer Institute database.
Of the almost 500,000 individuals between the ages of fifteen and thirty-nine with invasive cancer included in this study, 80% were white. This surprising finding was unaddressed by the researchers and is another stark example of the disparities in access to healthcare between white and non-white populations. Diagnosis of cancer at a later stage, or not at all, contributes to the worse cancer outcomes among non-white individuals that too often occur.
Overall, there was an increase in cancer incidence of almost 30% between 1973 and 2015. According to this research, colorectal, thyroid, and testicular cancers along with melanoma and non-Hodgkin lymphoma are most responsible for this increase in cancers among adolescents and young adults. Researchers suggest that the increase is likely due to a combination of environmental and lifestyle factors, and changes in screening and diagnosis.
Rates of obesity in adolescents and young adults have increased considerably in recent decades. For example, in 1998, 30.5 percent of young people were obese, compared to 42.4 percent in 2018. Given colorectal cancer’s strong link to obesity, the increasing obesity rates among adolescents and young adults likely also resulted in increased cancer rates as well. The increase in melanoma, which was greater among women than among men, may be due to increased sun and other sources of artificial UV exposure.
Changes in diagnostic procedures may also play a role in this large increase in cancer incidence. For example, advances in detection practices and imaging for thyroid cancer have resulted in more people being diagnosed with the disease. This does not mean that more adolescents and young adults are developing the disease than they were before, but now we have better technology to find people with thyroid cancer so they can be treated.
On the whole, cancer rates increased over the forty-two-year time period studied, but there were some exceptions. New cases of lung cancer and cervical cancer decreased over time, like due to a decrease in smoking rates and the discovery and availability of the vaccination for human papilloma virus (HPV) that protects against about 70% of cervical cancers.
To see an increase in cancer rates of 30% over forty-two years, especially with rates of some cancers going down, is concerning. While increases in obesity rates and improved detection methods of certain cancers explain some of the increase in cancer among adolescents and young adults, this large increase in cancer rates among a population group that is relatively healthy must be explored further. Cancer is the leading cause of disease-related deaths among young people. Advances in cancer prevention methods and treatment can have a huge, positive impact on the health of our nation’s adolescents and young adults so that they can be gaining independence and beginning their adult lives, not battling cancer.