Surge in Early-Onset Cancer Among Youth Raises Alarm

A notable increase in early-onset cancers, particularly among individuals under 50, has emerged as a concerning trend in recent years. This observation was underscored by a report from the National Cancer Institute, which indicated that rates of 14 different cancers surged between 2010 and 2019 in the United States. Among the alarming cases is that of an 18-year-old patient with metastatic kidney cancer, a situation previously unseen by Dr. Kimryn Rathmell, a kidney oncologist and former director at the NCI.

Dr. Rathmell’s initial impression was that younger patients were disproportionately referred to specialized cancer centres. However, the recent data has broadened her perspective. “I realised that what I was seeing was a trend that was happening everywhere,” she remarked, noting that the rise in early-onset cancers is evident across various types, including breast, colorectal, kidney, and pancreatic cancers.

While early-onset cancers remain relatively rare, their global incidence has increased significantly since 1990. For instance, in 2019, approximately 4,800 more cases of early-onset breast cancer were reported in the United States than what would have been anticipated based on 2010 rates. Although improvements in screening and detection may account for part of this rise, researchers suggest that deeper, underlying factors are at play.

Historical Context and Lifestyle Changes

Many cancer experts point to the 1950s as a pivotal period, noting that individuals born during this decade began experiencing higher rates of early-onset cancers starting in the 1990s. The risk appears to increase with each successive birth cohort; for example, those born in 1990 have a two- to threefold higher risk of specific cancers compared to those born in 1955.

Dr. Shuji Ogino, chief of molecular pathological epidemiology at Brigham and Women’s Hospital in Boston, attributes this trend to significant changes in lifestyle and environmental factors that began after World War II. These include reduced physical activity, increased consumption of processed foods and sugars, and exposure to various chemicals, including plastics and so-called “forever chemicals.” Furthermore, data indicate that sleep patterns have also deteriorated over the years.

While it is too soon to pinpoint the exact causes of rising early-onset cancers, Dr. Yin Cao, an associate professor at the Alvin J. Siteman Cancer Center in St. Louis, emphasizes the need for further investigation into potential risk factors. The link between obesity, alcohol consumption, and poor diet to early-onset cancer is increasingly supported by research.

Gender Disparities and Reproductive Factors

Women are particularly affected by early-onset cancers, with breast cancer being a leading concern. The average age for girls in the United States to begin menstruating has decreased to around 11 or 12, while the average age for first pregnancies has risen to 27.5 from the early twenties in the 1950s. This shift may contribute to increased breast cancer rates among younger women, as each menstrual cycle heightens the risk of cellular mutations.

Dr. Sherene Loi, a professor of oncology at the Peter MacCallum Cancer Center in Melbourne, explains that each cycle of hormone fluctuation may provide opportunities for mutations to occur. Additionally, Dr. Graham Colditz, an epidemiologist at the Siteman Cancer Center, highlights that the gap between the first period and first pregnancy exposes cells to harmful factors, such as radiation and alcohol, which can lead to cancerous changes.

Research indicates that women who experience obesity are nearly twice as likely to develop early-onset colorectal cancer compared to their counterparts with healthy body weights. A comprehensive review of nearly 15 million cancer cases in the U.S. found that the incidence of six out of twelve obesity-related cancers rose significantly among young adults between 1995 and 2014.

Emerging studies also suggest that exposure to certain environmental factors during early life or even in the womb may alter our genetic makeup, leading to a quicker progression towards cancer. For instance, Dr. Karuna Ganesh from the Memorial Sloan Kettering Cancer Center has indicated that young gut cells may revert to a less developed state under stress, making them more susceptible to aggressive mutations.

Research also points to the presence of specific bacteria, such as certain strains of E. coli, which produce toxins linked to cancer mutations. Dr. Ludmil Alexandrov from the University of California, San Diego, noted that these mutations often occur in early childhood, potentially setting children on a path toward cancer.

The interplay between environmental factors, immunity, and gene expression is becoming increasingly apparent in various cancers. Dr. dos Santos has demonstrated that urinary tract infections, which have been on the rise among women, can adversely affect breast tissue, facilitating the growth of precancerous cells.

As the conversation around early-onset cancer evolves, it is clear that mutations alone do not drive cancer development. Dr. Ogino notes that a significant portion of cancer risk—up to 40 percent—can be mitigated through lifestyle changes, including quitting smoking, limiting alcohol consumption, and maintaining a healthy weight.

The data underscores the importance of continued research to identify the underlying causes of rising early-onset cancer rates, as well as to develop effective prevention strategies.