February 4th marks World Cancer Day, a time to reflect on the global burden of cancer, as well as to celebrate advancements in screening that have resulted in decreased mortality from the second leading cause of death worldwide.
Nearly 20 million new cancer cases are diagnosed annually, with about 9.7 million deaths according to the most recent statistics published through the World Health Organization. This means that about one in five individuals will develop cancer at some point in their lifetime.
Worldwide, lung cancer was the most commonly occurring cancer, followed by breast cancer and then colorectal cancer. Lung cancer also remains the deadliest cancer, followed by colorectal cancer and liver cancer.
The United States carries a significant burden of cancer, with an estimate of more than two million cancers being diagnosed this year, according to the American Cancer Society. More than 600,000 cancer deaths are projected to occur in the U.S. in 2025 alone.
Despite these seemingly alarming numbers, cancer mortality rates continue to decline, as 4.5 million cancer deaths have been averted since 1991; largely due to improved screening programs, advancements in treatments and smoking reduction.
In America, cancer diagnoses have declined in men but have risen in women, particularly middle-aged and young females. For example, women younger than 50 years of age have an 82% higher incidence rate of cancer compared to men, which is up from 51% in 2002. Since 2021, even lung cancer cases in women have surpassed those seen in men.
The latest data on cancer both globally and specifically in America demonstrate the growing burden of cancer in middle-aged and young individuals, particularly women. The reasons for these emerging trends are not entirely clear, but many modifiable risk factors are known to contribute to cancer.
Alcohol, for example, is known to cause seven different cancers, including some that are on the rise in young women like breast cancer. Nearly two thirds of adult Americans (63%) drink alcohol according to a Gallup poll. Globally, 2.3 billion people drink alcohol, which means nearly 1 in 3 people drink according to the World Health Organization. As demonstrated by the outgoing U.S. Surgeon General’s Advisory on Alcohol, no amount of alcohol is safe and even small amounts can increase one’s risk of getting cancer, particularly breast cancer.
Furthermore, being overweight or obese is linked to at least 13 different cancers according to the CDC, including some that are on the rise in young individuals such as breast, thyroid and colon cancers. Nearly 75% of American adults are currently either overweight or obese, which undoubtedly contributes to the large cancer burden in America.
Future gains in cancer progress are threatened by socioeconomic and racial inequities that remain pervasive both globally and in America. Only 39% of countries worldwide cover the basics of cancer management for their citizens, according to the WHO global survey on universal health coverage. As an example, lung cancer health services were four to seven times more likely to be included in high income countries when compared to low income countries.
Racial disparities, particularly in America, are also alarming. Native Americans have the highest cancer mortality, and are two to three times more likely to die from kidney, liver, stomach and cervical cancers when compared to White Americans. Black Americans are two times more likely to die from prostate, stomach and uterine cancers when compared to White Americans. These inequities underscore the importance to expanding screening programs to all people, increasing access to care in both rural and low-income neighborhoods as well as enacting policies to combat systemic racism in healthcare. This can be accomplished, in part by expanding universal healthcare coverage as well as Medicaid in all states, as well as addressing racial bias in healthcare institutions through implicit bias training and standardized treatment protocols.
The good news is cancer deaths are decreasing globally. Despite this very important stride, the global burden of inequities and disparities in cancer care serves as a stark reminder of just how much work still needs to be done.
