Early-onset cancers, typically defined as those diagnosed in people aged approximately 20 - 50, have continually increased over the past several decades. Studies have shown that the growing incidence of early-onset cancers is occurring globally, indicating a substantial public health challenge. Evidence shows various cancer types, including bone marrow, breast, colorectal, endometrial, esophageal, head and neck, liver, pancreatic, stomach, and thyroid cancers.
While experts attribute some of the rise in early-onset cancer diagnoses to advancements in diagnostic and screening techniques, a candid increase in incidence has materialized. Identifying the risk factors associated with an early-onset cancer diagnosis could significantly benefit public health by informing practical approaches for prevention, early detection, and treatment.
A recent publication in Nature Reviews Clinical Oncology has reviewed the literature on the rising incidence rates of early-onset cancers and analyzed global data on several cancers in which diagnoses in young adults are on the rise. The authors describe how the exposome, the culmination of all exposures, including diet, lifestyle, and environment, has dramatically changed since the mid-20th century.
Indeed, cancer-contributing risk factors such as alcohol consumption, height, obesity, and sedentary lifestyle have increased in both adult and adolescent populations in several regions worldwide. Antibiotic use has increased in recent decades and alters an individual’s microbiota, and associations between certain cancers and antibiotics have emerged. Type 2 diabetes mellitus (T2D) incidence, a disease strongly linked to cancer, has also increased in children and adults. Diet presents another factor that has substantially evolved in the past fifty years. Diets high in saturated fats, red meat, and sugar (sometimes known as a Western-style diet) have increased globally.
The authors conclude that while the precise reasons underlying the increased development of early-onset cancers remain unclear, significant changes to risk factors in the exposome during childhood, adolescence, or young adulthood over the past fifty or so years likely play a key role. The manuscript also highlights the need to begin prospective studies, including analysis of biological specimens, such as blood or tissue, donated from young participants. Finally, the researchers call on scientists, health-care professionals, lawmakers, and the public to raise awareness of early-onset cancers, enact preventative measures, especially among young adult populations, and promote cancer screening regimens.
Sources: Nat Rev Clin Oncol, J Natl Cancer Inst (Gupta), Cancer, Lancet Glob Health, J Natl Cancer Inst (Lortet-Tieulent), Cancer Epidemiol Biomark Prevent, Arch Otolaryngol Head Neck Surg, Liver Cancer, Gastroenterol, JAMA Netw Open, Thyroid, Cancers