For people under 50 colon cancer is now the deadliest type of cancer.
Data published in the Journal of the American Medical Association show that colorectal cancer death rates in this age group have increased by about one per cent annually since 2005. This is in contrast to overall cancer mortality among people under 50, which has fallen by approximately 44 per cent since 1990.
“It’s not surprising,” said Sunil Patel, a colorectal surgeon at Kingston Health Sciences Centre (KHSC) and associate professor of surgery at Queen’s University. “Literature demonstrating increasing incidence of colon cancer in people under 50 has been around for a number of years now.”
Patel noted that colorectal cancer’s rise to the top of the rankings is due to both increased incidence and declines in other types of cancer mortality. Lung cancer, once the leading cause of cancer death in younger adults, has dropped substantially due to lower smoking rates, while breast cancer mortality has also decreased with improved diagnosis and treatment. Of the five most common causes of cancer-related death in people under 50, colorectal cancer’s the only one with increasing mortality.
The term “early-onset colorectal cancer” is commonly used to describe diagnoses before age 50, but Patel said it can be misleading. “When people hear ‘early-onset’, they think of very young patients,” he said. “Really, early age onset colorectal cancer usually represents people in their 40s. Patients under 40, and especially under 30, are still very rare.”
Even so, younger patients may have worse outcomes. According to a Patel, colorectal cancers in younger adults tend to be more aggressive, particularly in those under 40, a claim supported by literature. “They have a higher risk of dying from their cancer compared to patients diagnosed later in life,” Patel said. “We don’t fully understand why.”
In southeastern Ontario, early-onset cases still account for a minority of colorectal cancer diagnoses, but Patel said he is seeing more patients in their 40s relative to previous years. Very young patients tend to stand out in clinicians’ memories, which can make the trend feel more striking. “Those diagnosed at a very young age are the most memorable,” he said. “We clearly remember the patient who was 21 when they were diagnosed.”
As for causes, genetics doesn’t appear to explain the increase. According to Patel, most patients diagnosed with colorectal cancer don’t have known inherited mutations, and those mutations aren’t becoming more common. That points to environmental or lifestyle factors, though evidence remains limited. Associations have been found with obesity, low fibre intake, and diets high in ultra-processed foods, but no single factor clearly explains the trend. “We can assume it’s something environmental,” Patel said. “But we don’t actually know what’s driving it.”
For younger adults, symptoms are another challenge. Many early signs of colorectal cancer, such as abdominal pain, overlap with common, benign conditions, especially in people in their 20s and 30s. Still, Patel emphasized that some symptoms should never be ignored. New rectal bleeding is the most important red flag, even though cancer accounts for only a small fraction of cases. Persistent changes in bowel habits, unexplained pain, or symptoms that worsen over time also warrant medical attention.
“Young patients often notice symptoms for a while and ignore them,” Patel said. “They’re not thinking about cancer, they’re busy, and they don’t always want to seek care.” Symptoms can also be dismissed out of embarrassment, he said.
There is, however, good news on both prevention and treatment. Ontario is expected to lower the starting age for colorectal cancer screening from 50 to 45, a change Patel says will help identify early-onset cases. “Screening is the best evidence-based practice we have,” he said. “When you turn 45, it’s a good idea to get screened.”
Treatment has also improved. Minimally invasive and robotic-assisted surgeries now allow most colorectal cancer patients at KHSC to avoid open surgery. Hospital stays are often one to two days, compared to several days in the past, and recovery is significantly faster. “Patients can get back to work, school, and daily life much faster, sometimes as soon as two weeks after the surgery,” Patel said.
For students and young adults, Patel stressed that colorectal cancer remains uncommon but may not be limited to older populations. Symptoms that persist or worsen shouldn’t be dismissed, and seeking care early is important. “You don’t need to tell your friends or classmates,” he said. “But you should speak with a healthcare professional.”
Tags
Breast cancer, cancer, KHSC, Kingston Health Sciences Centre, Lung Cancer
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