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

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

Colorectal cancers in people under 50 years of age were usually preceded by rectal bleeding, abdominal pain and changes in bowel habits.

In addition, many patients experience anemia, weight loss and fatigue.

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

Young patients are urged to undergo a colonoscopy if they experience any of these symptoms, as they are not routinely screened for the disease.

The figures come as colorectal cancer rates are expected to double between 2010 and the end of this decade – an alarming increase that doctors are still trying to sort out.

“Early-onset colorectal cancer (EOCRC), defined as a diagnosis under age 50, is increasing, and so-called red flag signs and symptoms in these individuals are often missed, leading to diagnostic delays,” the researchers wrote.

‘Better recognition of the signs and symptoms associated with EOCRC could facilitate timely diagnosis and influence clinical outcomes.’

The research team used the data to determine which symptoms were most common, which signs put patients at greatest risk for colon cancer, and how long it took for patients to be diagnosed with colon cancer.

They found that rectal bleeding was associated with a fivefold increase in the risk of early-stage colon cancer, making it the biggest risk factor.

In addition, in one in ten patients, symptoms occurred quickly and severely.

The researchers initially searched 12,859 research articles and narrowed the list to 81 studies conducted between 2000 and 2023.

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

In addition, 27 percent had changes in their bowel habits, including more or less movements.

Weight loss was observed 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 to receive a diagnosis.

“Younger patients may experience persistent signs and symptoms and delay seeking medical care,” the researchers wrote.

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

And even if a patient does seek medical attention, “both patients and physicians may downplay the severity of symptoms and fail to recognize key warning signs and clinical clues that should raise suspicion of colorectal cancer,” the team said.

They noted that rectal bleeding, the most common symptom, is too often attributed to harmless conditions such as hemorrhoids.

A 2020 study by Colorectal Cancer AllianceFor example, research found that 68 percent of patients had blood in their stools, and many of them were misdiagnosed or rejected.

More than half of participants said they had been misdiagnosed with conditions such as hemorrhoids, IBS, anemia and mental health problems.

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

Alarmingly, these are the age groups in which colon cancer is rising fastest. Recent statistics suggest that the incidence of colon cancer has increased by 500 percent in children aged 10 to 14 and by 333 percent in teenagers aged 15 to 19.

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

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

Overall, “diagnostic delays after presentation of signs or symptoms are up to 40% longer compared with older individuals with colorectal cancer,” the researchers wrote.

They advised doctors to work with patients to ensure the diagnosis is made quickly. They also suggested that patients should request a colonoscopy or stool test if they experience symptoms.

The review appeared in the magazine last week JAMA network opened.