Red flags indicate early-onset colorectal cancer risk

Researchers at Washington University School of Medicine in St. Louis have identified four important signs and symptoms that signal a high risk for early colorectal cancer. These red flags may be the key to earlier detection and diagnosis of early colorectal cancer in young adults. The number of young adults with colorectal cancer has nearly doubled in recent years.

By studying anonymized health insurance data on more than 5,000 patients with early-onset colorectal cancer (cancer that occurs before the age of 50), researchers found that between three months and two years before diagnosis, abdominal pain, rectal bleeding, diarrhea and iron deficiency anemia each indicate an increased risk in those under 50 years of age. They found that having just one of the symptoms nearly doubled the risk; having two symptoms increased the risk more than 3.5 times; and having three or more increased the risk more than 6.5 times.

The study is published on May 4 in the Journal of the National Cancer Institute.

“Colorectal cancer is not just a disease of older people; we want young adults to be aware of these potentially very telling signs and symptoms and to act on them, particularly because people under 50 years are considered low risk and do not receive routine colorectal cancer screening,” said lead researcher Yin Cao, ScD, associate professor of surgery in the Division of Public Health Sciences and research fellow from the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine.

“It is also crucial to raise awareness among primary care physicians, gastroenterologists and emergency physicians,” Cao said. “To date, many early colorectal cancers are detected in emergency rooms, and there are often significant diagnostic delays with this cancer.”

Cao said two symptoms in particular – rectal bleeding and iron deficiency anemia, a condition in which there are not enough healthy red blood cells to carry oxygen – point to the need for endoscopy and a timely follow-up.

In this study, Cao, along with first author Cassandra DL Fritz, MD, assistant professor of medicine in the Division of Gastroenterology, and co-first author Ebunoluwa Otegbeye, MD, resident in general surgery, analyzed cases of early-onset colorectal cancer and matched controls using the IBM MarketScan commercial database, a big data tool that provides anonymized longitudinal information based on health insurance claims data from approximately 113 million insured adults aged 18 to 64 years old.

“It usually takes about three months to get a diagnosis from the time a person first goes to the doctor with one or more of the warning signs and symptoms we’ve identified,” Fritz said. “But in this analysis, we found that some young adults had symptoms up to two years before their diagnosis. This may partly explain why many of these young patients had more advanced disease at the time of diagnosis than what we normally see in older people who get tested regularly.”

People born in 1990 have a double risk of colon cancer and four times the risk of rectal cancer than young adults born in 1950. This trend has prompted the National Cancer Institute, American Cancer Society, American Gastroenterological Association and other professional societies to prioritize research. on identifying risk factors and improving early detection. In 2021, the United States Preventive Services Task Force lowered the recommended age for colorectal cancer screening from 50 to 45.

Cao, also an associate professor of medicine, leads a research group focused on identifying risk factors and molecular variations in early colorectal cancer. His group is among the first to report that obesity, prolonged sitting, metabolic syndrome, diabetes, sugary drinks and other risk factors may contribute to increased incidence of early colorectal cancer.

According to the American Cancer Society, although the death rate from colorectal cancer has been declining for several decades among older adults due to regular colonoscopies and improved treatment, more younger people are being diagnosed with the disease in advanced stages. and many die of the disease. .

Such a change suggests that there is an urgent need to recognize the symptoms as soon as possible.

“Since the majority of cases of early-onset colorectal cancer have been and will continue to be diagnosed after presentation of symptoms, it is crucial to recognize these warning signs and symptoms early and to perform a diagnostic work-up as soon as possible. as possible,” Cao said. said. “By doing so, we can diagnose the disease earlier, which may reduce the need for more aggressive treatment and improve quality of life and patient survival rates.”