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HomeOncologyVital early signs of colon cancer in young adults – US study

Vital early signs of colon cancer in young adults – US study

Prolonged bouts of diarrhoea, stomach aches and blood during bowel movements may be signs of early-onset colorectal cancer, according to recent research, which pinpointed four distinct signals up to two years before diagnosis in a disease escalating among young adults not old enough to qualify for colonoscopies.

The most troubling early symptom is rectal bleeding, a possible sign of colon cancer that’s not comfortably discussed beyond the bathroom, said Dr Matthew Kalady, the director of the division of colon and rectal surgery at the Ohio State University Comprehensive Cancer Centre.

“But it’s important to understand what's normal and what’s not.”

The latest research, from Washington University School of Medicine and published in the Journal of the National Cancer Institute, included 5 075 people with early-onset colorectal cancer.

The scientists’ goal was to find symptoms indicating early signals of colorectal cancer, which has surged among younger people in recent years and with a troubling number not being diagnosed until advanced stages, reports NPR News.

The American Cancer Society said cases in people under 55 had doubled from 1995 to 2019, from 11% to 20%.

The study found four signs up to 24 months before a colorectal cancer diagnosis:

• Abdominal pain
• Rectal bleeding
• Ongoing diarrhoea
• Iron deficiency anaemia – anaemia is usually found in yearly blood tests

Participants had at least one of those symptoms that began as early as two years before diagnosis.

However, colonoscopies are recommended only at or after age 45. That means people may have symptoms long before they seek doctors’ care or are ever diagnosed with colon cancer – a treatable disease if it’s caught early, experts say.

“As patients, we often brush these things away,” said an author of the study, Dr Cassandra Fritz, an assistant professor of medicine in the division of gastroenterology at the Washington University School of Medicine.

“But these symptoms should alarm you to see a doctor,” she said.

Nearly half of the study participants experienced at least one of those symptoms three months before they were diagnosed. The risk for cancer diagnosis rose as additional symptoms popped up.

The research highlights an “alarming problem” for young adults and their doctors, said another author of the study, Yin Cao, an associate professor of surgery in the public health sciences division at Washington University School of Medicine.

The worry is that doctors, gastroenterologists and younger people are too often misdiagnosing or ignoring symptoms.

“Often, many early-onset colorectal cancers are detected only in emergency rooms, and there are often significant diagnostic delays with this cancer.”

Study details

Red-flag signs and symptoms for earlier diagnosis of early-onset colorectal cancer

Cassandra Fritz, Ebunoluwa Otegbeye, Xiaoyu Zong, Joshua Demb, Katelin Nickel, Margaret Olsen, Matthew Mutch, Nicholas Davidson, Samir Gupta, Yin Cao.

Published in the Journal of the National Cancer Institute on 4 May 2023


Prompt detection of colorectal cancer under age 50 (early-onset CRC) is a clinical priority due to its alarming rise.

We conducted a matched case-control study of 5075 incident early-onset CRC among U.S. commercial insurance beneficiaries (113 million adults aged 18-64) with ≥2 years of continuous enrolment (2006-2015) to identify red-flag signs/symptoms between 3 months to 2 years before the index date among 17 pre-specified signs/symptoms. We assessed diagnostic intervals according to the presence of these signs/symptoms before and within 3 months of diagnosis.

Between 3 months to 2 years before the index date, four red-flag signs/symptoms (abdominal pain, rectal bleeding, diarrhoea, and iron deficiency anaemia) were associated with an increased risk of early-onset CRC, with ORs ranging from 1.34 to 5.13. Having 1, 2, or ≥ 3 of these signs/symptoms were associated with a 1.94 (95% CI, 1.76 to 2.14), 3.59 (2.89 to 4.44), and 6.52 (3.78 to 11.23)-fold risk (Ptrend < .001), with stronger associations for younger ages (Pinteraction < .001) and rectal cancer (Pheterogenity=0.012). The number of different signs/symptoms was predictive of early-onset CRC beginning 18 months before diagnosis. About 19.3% of cases had their first sign/symptom occur between 3 months to 2 years before diagnosis (median diagnostic interval: 8.7 months), and around 49.3% had the first sign/symptom within 3 months of diagnosis (median diagnostic interval: 0.53 month).

Early recognition of red-flag signs and symptoms (abdominal pain, rectal bleeding, diarrhoea, or iron-deficiency anaemia) may improve early detection and timely diagnosis of early-onset CRC.


Journal of National Cancer Institute abstract – Red-flag Signs and Symptoms for Earlier Diagnosis of Early-Onset Colorectal Cancer (Open access)


NBC Health article – As colon cancer spreads in younger adults, new research identifies earliest symptoms (Open access)


See more from MedicalBrief archives:


More younger people being diagnosed with colorectal cancer


US team designs novel mapping of colorectal cancer


Antibiotic use linked to increased risk of colon cancer — Swedish Colorectal Cancer Registry


Sugary drinks associated with increased risk of colorectal cancer in women








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