The 17 ‘red flag’ colorectal cancer symptoms young people need to look out for, according to study of 25million patients

A major study has revealed the 17 most common symptoms of the fastest growing cancer in young people.

Colorectal cancer diagnoses in people under 50 were most often preceded by rectal bleeding, stomach pain, and changes in bowel movements.

Unexpected weight loss, fatigue, changes to appetite and other digestive issues were among the most common symptoms associated with the disease.

Researchers in six countries including the US made the finding after analyzing data from more than 80 studies, which included nearly 25million colorectal cancer patients under 50. 

Young patients are being urged to get checked if they suffer any of these symptoms because they are not routinely screened for the disease. 

The finings come as colorectal cancer rates are expected to double from 2010 to the end of the decade.

Doctors are still trying to work out what’s behind the rapid rise. Processed foods, chemical contamination and the overuse of antibiotics have all been touted as possible factors. 

‘Early-onset colorectal cancer (EOCRC), defined as a diagnosis at younger than age 50 years, is increasing, and so-called red flag signs and symptoms among these individuals are often missed, leading to diagnostic delays,’ the researchers wrote.

‘Improved recognition of presenting signs and symptoms associated with EOCRC could facilitate more timely diagnosis and impact clinical outcomes.’ 

The research team used the data to determine which symptoms were most common, which signs put patients most at risk of colon cancer, and how long it took patients to get a colon cancer diagnosis. 

They found that rectal bleeding was linked to a five-fold increase in early onset colon cancer risk, making it the largest risk factor.  

Additionally, one in 10 patients had their symptoms come on quickly and severely. 

The researchers initially combed through 12,859 research papers and narrowed down the list to 81 studies conducted between 2000 and 2023. 

They found that 45 percent of patients experienced rectal bleeding or blood in their stool, and 40 percent suffered abdominal pain. 

Additionally, 27 percent had changes in their bowel habits, which could include having more or fewer movements. 

Weight loss was seen in 17 percent of patients, while 15 percent had a loss of appetite. 

And while 12 percent had an acute presentation, meaning their symptoms came on quickly, it took an average of four to six months for them to get a diagnosis. 

‘Younger patients may experience ongoing signs and symptoms and delay seeking medical attention,’ the researchers wrote. 

‘Potential reasons for these delays include a patient believing they are too young to worry about cancer or a lack of access to primary care of health insurance.’ 

And even if a patient does seek medical help, ‘patients and clinicians alike may downplay symptom severity and fail to recognize key red flags and clinical cues that should trigger suspicion of colorectal cancer,’ the team said. 

They noted that, too often, rectal bleeding, the most common sign, is attributed to harmless conditions like hemorrhoids. 

A 2020 survey from Colorectal Cancer Alliance, for example, found that 68 percent of patients experienced blood in their stool, and many of them were misdiagnosed or dismissed.

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More than half of the participants said they were misdiagnosed with conditions such as hemorrhoids, IBS, anemia, and mental health issues. 

Patients ages 19 to 39 were the most likely to feel dismissed, the team found.

Alarmingly, these are the age groups that colon cancer is rising the quickest in. Recent statistics suggest that colon cancers have grown by 500 percent in children ages 10 to 14 and 333 percent in teens ages 15 to 19. 

The American Cancer Society estimates there will be 106,590 cases of colon cancer and 46,220 instances of rectal cancer this year, along with 53,010 deaths. 

It’s currently the fourth most common cancer in the US behind lung, prostate, and breast cancers. And nearly one in four patients are diagnosed after the disease has already spread to other organs. 

Overall, ‘delays in diagnostic workup after sign or symptom presentation are up to 40% longer compared with older individuals with colorectal cancer,’ the researchers wrote. 

They advised doctors to work with patients to ensure they are diagnosed quickly. They also suggested patients should ask for a colonoscopy or stool test if they experience symptoms.

The review was published last week in the journal JAMA Network Open.