A rise in early-onset cancers, particularly among millennials, is prompting urgent questions about causes and risk factors

Cancer rates are increasing among younger adults, sparking concerns across the medical community and among the general public. The question on everyone’s mind: Why are so many young people suddenly being diagnosed with cancer?

Recent data has raised alarms. One in five new colorectal cancer patients in the United States is now under 55, nearly double the rate observed in 1995. A study led by the American Cancer Society found that 17 out of 34 common cancers, including those of the small intestine, pancreas, and kidney, are becoming more frequent in younger populations. Some of these cancers, which had been declining in the past, are now on the rise again.

While death rates from colorectal cancer in patients aged 65 and over are dropping, the situation for younger patients is more concerning. Early-onset cancers tend to be more aggressive and harder to treat, partly because they are often detected too late. Colonoscopies, for example, are not typically recommended until age 45, leaving younger individuals vulnerable to undiagnosed cancers.

The million-dollar question, however, remains: Why is this happening, particularly to millennials? Although scientists do not have a definitive answer yet, there are a few promising avenues of investigation.

Experts point to lifestyle factors, such as diet and exercise, which have long been recognised as significant contributors to cancer risk. The increase in global obesity rates since the mid-1990s is likely playing a pivotal role in the rise of cancers, especially those of the gastrointestinal tract. Obesity has been linked to various types of cancers due to factors like inflammation and hormonal imbalances, which can promote the growth of cancer cells.

However, researchers believe that something more may be at play, particularly when considering generational shifts. The rise in cancer cases seems particularly pronounced in the millennial generation, suggesting that environmental and lifestyle factors, along with genetic changes, could be influencing cancer risk in new ways. As millennials came of age during an era marked by rapid technological and social change, including significant changes to the food supply, pollution levels, and exposure to chemicals, scientists are exploring whether these factors could be contributing to the rise in cancers.

Another potential factor that has emerged in recent studies is the role of early-life exposures, including the environment and nutrition during childhood. There is increasing evidence that what happens during early development may significantly affect cancer risk later in life. Furthermore, researchers are looking into the role of microbiomes—complex communities of bacteria living in the gut—which may be impacted by diet and lifestyle choices and could influence cancer susceptibility.

While much remains uncertain, researchers agree that addressing early-onset cancers in young adults will require a multifaceted approach. Public health campaigns aimed at improving diet, exercise, and early screening could play an important role in mitigating the rising cancer rates in younger populations.

Despite the unsettling trend, scientists remain optimistic that with continued research and improvements in early detection, these cancers can be better understood and, in time, more effectively treated. But as the situation stands, one thing is clear: the increase in cancer rates among younger adults is a significant issue that warrants further attention, investment, and research to understand its causes fully.