Cancer has long been a major health challenge, but recent data shows a disturbing trend: an increasing number of young adults under 50 are being diagnosed with various types of cancer. In 2024 alone, it is estimated that there will be over 2 million new cases in the United States, with approximately 611,720 related deaths, according to the National Cancer Institute (NCI). Among these cases, a troubling rise in early-onset cancers—those diagnosed in younger people—has researchers scrambling to uncover causes and potential solutions.
Why?
One obvious factor driving cancer rates is a lifestyle marked by obesity, processed foods, and sedentary habits, particularly prevalent in the U.S. Dr. Goldfarb explains, “Obesity causes inflammation, which can lead to cancer.” However, this explanation only partly addresses the growing rates, such as those of young women with breast cancer or the cases observed at Memorial Sloan Kettering Cancer Center (MSK)’s Center for Young Onset Colorectal and Gastrointestinal Cancer. Dr. Robin Mendelsohn, co-director at MSK, suggests that “there isn’t a single smoking gun,” but rather, a set of interconnected factors.
Dr. Marcia Cercek of MSK speculates on a deeper issue: environmental exposure. She notes, “The hypothesis is that environmental exposures affecting people born in the 1950s onward may play a role.” Possible triggers from the 1960s and 70s—such as exposure to pollutants, dietary changes, and increased antibiotic use—could be compounding over generations.
Researchers at MSK are also studying another possible factor: the microbiome. Known as the “invisible organ,” the microbiome is a diverse community of bacteria in our digestive system that plays a vital role in maintaining health. Dr. Mendelsohn presented findings showing that young adults with colorectal cancer had less microbial diversity compared to older patients, which can negatively impact health. This led MSK researchers to investigate the microbiome’s interactions with lifestyle factors, including diet, medications, and even early childhood influences like breastfeeding and birth delivery methods.
With so many possible contributing factors, it’s likely that several overlapping elements are at work. Yet researchers remain hopeful. As Dr. Mendelsohn explains, “Our goal is to find a possible trigger that would explain why the microbiomes of these patients are different.” Uncovering this could lead to targeted prevention measures, potentially reversing this troubling trend affecting young adults worldwide.
