The recent disclosure of Catherine, Princess of Wales’ cancer diagnosis shocked many observers. She is 42 years old. As a medical oncologist, it is disheartening to say that this news does not come as a shock.

Cancer that occurs in adults under 50 years of age, known as early-onset cancer, is not uncommon. Interestingly, there is a growing global trend where individuals diagnosed with cancer are becoming younger. Moreover, it challenges the misconception that cancer only affects older individuals.

Last week, I encountered a patient who was 37 years old and unfortunately had breast cancer that had spread to various parts of her body, including her lymph nodes, bones, lung, and liver. Next door, there was a patient in their mid-forties who unfortunately had colon cancer that had spread extensively to the liver, causing it to become filled with tumors. Both patients were diagnosed with stage IV cancers that can be managed for a limited period, but unfortunately, they cannot be cured.

According to a study published in the journal BMJ Oncology, there has been a significant increase in the global incidence of early-onset cancer and early-onset cancer deaths from 1990 to 2019. The study reported a 79.1% rise in early-onset cancer cases and a 27.7% increase in early-onset cancer deaths during this period. Last year, the Journal of the American Medical Association published more detailed data on this increase. It revealed that in the United States from 2010 to 2019, breast cancer was the most common type of cancer among younger individuals, while rates of gastrointestinal cancers were increasing rapidly.

The significant rise in gastrointestinal cancers alone highlights the profound implications and risks linked to an individual’s year of birth. According to Dr. Kimmie Ng, a medical oncologist at Dana-Farber Cancer Institute, there has been a significant increase in the risk of colon cancer for individuals born in 1990 compared to those born in 1950. And increase the chances of developing rectal cancer fourfold.

With the increasing number of early-onset cancers, it is crucial to understand the reasons behind this rise and identify those who are more susceptible to the disease. It seems that the answer lies in the shifts in nutrition and lifestyle that became prevalent during the mid-20th century.

It is worth mentioning that the genetic risks to the population have remained constant over the past few decades. This strengthens the argument that environmental and lifestyle factors play a more significant role in the development of these cancers than our genes. Possible factors that contribute to the issue are ultraprocessed foods, sugary drinks, red meat, smoking, alcohol, sleep disturbances, obesity, and a lack of physical activity. Whether we are by ourselves or in a group, these factors have the ability to disrupt our body’s internal processes, leading to changes in metabolism and increased inflammation.

Ongoing research is currently investigating the potential link between alterations in the gut microbiome and the heightened susceptibility to cancer in our bodies. This community of microbes plays a vital role in maintaining good health, impacting important bodily functions such as digestion and the immune system. Unhealthy eating habits, overuse of antibiotics, and certain medications can disrupt the delicate balance of this microbiome, potentially contributing to the development of cancer.

Given that cancer is a condition that typically progresses over many years as genetic mutations accumulate and give rise to tumors, it is possible for someone who is diagnosed at a young age to have been exposed to certain risk factors during infancy or in the womb. Currently, there is a strong focus on research in this area. Studies have found a potential higher risk associated with cesarean delivery in females, as well as with the use of a synthetic form of progesterone to prevent premature labor.

However, in my own cancer clinic, I have observed that obesity and lifestyle are not the sole factors contributing to the diagnosis of young patients. A significant number of the individuals I am currently treating maintain a healthy lifestyle by practicing mindful eating habits and engaging in regular physical activity. And so the causes of their diseases continue to elude scientific understanding.

According to Dr. Suneel Kamath, a gastrointestinal medical oncologist at the Cleveland Clinic Taussig Cancer Institute and member of the recently established Center for Young-Onset Colorectal Cancer at the Cleveland Clinic, the answer to this question remains uncertain.

It is clear that the underdiagnosis of these early-onset cancers is both widespread and significant. It is crucial for primary care physicians to be well-informed about the increasing prevalence of cancer among individuals under the age of 50. They should understand that age should not be used to dismiss or underestimate a patient’s symptoms.

However, it is important for individuals to pay attention to persistent symptoms and be aware of any family history of cancer. It is not uncommon for young patients to find themselves in a position where they need to assertively advocate for their own needs. Unfortunately, it can be a lengthy process involving multiple appointments before a cancer diagnosis is reached.

Early-onset cancers were previously believed to be biologically distinct and more aggressive than cancers that occur later in life, likely due to the fact that they are often diagnosed at advanced stages. Many times, these cases are discovered at a later stage when they have already spread, primarily because of a delay in diagnosis rather than any inherent aggressiveness.

Once treatment begins, the circumstances change for individuals in their 20s, 30s, and 40s. The long-term effects of cancer drugs may include cardiovascular problems and the development of secondary cancers, even years after treatment. Some patients who are younger may find themselves in the early stages of pregnancy when they begin therapy, or they may have concerns about how the treatment will impact their fertility. In addition, there are valid concerns regarding potential long-term cognitive impairment following chemotherapy, particularly as individuals transition back into the workforce.

“Discussing the challenges of balancing college and parental responsibilities while undergoing chemotherapy can be quite unsettling,” Kamath expressed. It is unfortunate that these individuals are tasked with handling this situation.

This concerning trend in cancer care calls for a renewed commitment to funding, additional research, educational initiatives, and updates to screening guidelines.

There are already many things in motion. It is worth mentioning that the US Preventive Services Task Force, a dedicated group of disease prevention experts, has recently advised that individuals at average risk of colorectal cancer should begin screening at the age of 45.

Despite significant advancements in cancer outcomes, it is concerning to see certain age groups lagging behind, which prevents us from claiming true progress. The recent announcement by the Princess of Wales about her battle with cancer serves as a poignant reminder of the ongoing efforts that still need to be made.