Identifying 2 'Red Flag' Symptoms of Early-Onset Colorectal Cancer: New Research

Recent studies have highlighted two alarming symptoms linked with nearly 50% of all early-onset colorectal cancer cases: abdominal pain and blood in the stool, which is also known as hematochezia.

In the United States, colorectal cancer generally affects older individuals, with the average age of diagnosis being 66. Nonetheless, the occurrence of early-onset colorectal cancer, which pertains to cases diagnosed in individuals below 50, has surged and doubled since the 1990s.

A review that was published in JAMA Network Open on May 24 scrutinized 81 studies with data collated from over 24 million people below 50. These studies concluded that people with early-onset colorectal cancer most frequently experienced blood in their stool, abdominal pain, and changed bowel habits both in the U.S. and across the globe.

Kishore Guda, PhD, DVM, an associate professor at the Case Western Reserve University Comprehensive Cancer Center, stated that the study underscores the importance of immediate medical consultation if any abnormalities are noticed.

A rise in colorectal cancer incidence in younger individuals requires researchers to identify any recurring symptoms in this age group to avoid overlooking or underestimating them.

Upon thorough examination of 81 studies carried out in various parts of the world, data from almost 25 million people was compiled. The researchers established that 45% of individuals with early-onset colorectal cancer had hematochezia, or bloody stool, and around 40% reported having abdominal pain. The third most common symptom for early-onset colorectal cancer, which affected 27% of individuals, was altered bowel habits including constipation, diarrhea, alternating bowel habits, or alternating diarrhea and constipation. 

The review identified an increased risk of colorectal cancer in individuals with rectal bleeding and abdominal pain as compared to those without these symptoms. Across 34 studies, it was found that patients were diagnosed with early-onset colorectal cancer typically four to six months after experiencing symptoms.

Earlier research has already acknowledged these “red flag” symptoms, but the latest study included data from a larger group of individuals and emphasized the importance of younger people recognizing the warning signs of the disease.

The review did not expressly probe the reasons behind the delay in diagnosing colorectal cancer despite individuals experiencing symptoms. The authors suggested that the problem could be attributed to both younger people and physicians.

An average individual below 50 may not seek medical assistance immediately after experiencing these symptoms or may face obstacles such as arranging childcare or healthcare access, as observed by Yi-Qian Nancy You, MD, professor of surgery, and director of the Young-Onset Colorectal Cancer Program at the University of Texas MD Anderson Cancer Center. As Guda pointed out, younger individuals may not instantly associate these symptoms with cancer.

In contrast, healthcare providers may downplay the severity of these symptoms and assume they indicate a less significant condition.

"Frontline providers, such as ER physicians or a primary care physician, may not immediately suspect cancer," You noted, which can further delay the diagnosis.

Guda explained that while most times these symptoms indicate less severe conditions like diverticulitis in the colon, hemorrhoids, or inflammatory bowel disease, neglecting these symptoms or delaying medical treatment can lead to serious health complications.

Regardless of age, everyone should be aware of colorectal cancer symptoms and seek medical attention if they experience any abnormalities, suggests Guda.

This is especially important because, by the time someone has symptoms of colorectal cancer, the case could be a bit more serious. 

“Young patients present at a little bit later stage, so two-thirds of them are already stage three or stage four by the time they’re diagnosed,” said You. “That may or may not translate to a tumor that’s a little more symptomatic.”

The U.S. Preventive Services Task Force recommends people start getting screened for colorectal cancer at age 45. People with a high genetic risk for colorectal cancer may start getting regular colonoscopies even earlier. But in general, “there are no particular guidelines” for finding asymptomatic colorectal cancer in younger people, Guda explained.

“How do we identify people who are at a higher risk of early-onset colorectal cancer? There is not an easy answer,” he said.

If someone is experiencing one of these symptoms, there's no need to panic, experts emphasized.

'It's really hard to take a symptom as a stand-alone red flag to trigger a whole massive workup for cancer,' said You. 'We can't just go 100% over to the other end of the spectrum.'

However, if stomach pain, bowel changes, or other issues persist—especially if you're experiencing more than one—you shouldn't ignore it, You explained.

If someone is experiencing some of these symptoms, they can try using an at-home stool test to check for colorectal cancer, Guda suggested. But again, having a healthcare provider assess your symptoms is the best course of action. If necessary, they can help screen you for colorectal cancer via a colonoscopy or some other test. 

In general, there’s a higher chance that someone will recover from cancer when it’s caught early and treated early. 

“You know your body well,” said Guda. “If you have anything like [these symptoms], just go and get it checked. Get a workup, get a colonoscopy, try to rule in or rule out things, and do it quickly, too.”