Colorectal cancer is increasingly affecting people at younger ages, and genetics may be part of the cause. Symptoms like rectal bleeding may be early warning signs and should be checked out right away by a healthcare provider. Despite this concerning cancer trend, five-year survival rates in people younger than age 65 reach 94% with early diagnosis and treatment.
Watch for These Signs of Colorectal Cancer
Colorectal cancer symptoms can go unnoticed in the early stages of the disease. A 2023 study identified four “red flag” symptoms that were signs of early-onset colorectal cancer, appearing at least two years before a colorectal cancer diagnosis:
- Abdominal pain
- Rectal bleeding
- Ongoing diarrhea
- Iron deficiency anemia
“Our findings are important and timely because of the rising incidence of colorectal cancer in young adults,” Cassandra Fritz, MD, MPHS, an author of the study and an assistant professor of medicine in the Division of Gastroenterology at Washington University School of Medicine, told Verywell. “Awareness of these symptoms could improve earlier detection of early-onset colorectal cancer.”
Trends in Early Diagnosis of Colorectal Cancer
Researchers warn that by 2030, about 15% of all colorectal cancer cases will be diagnosed in people younger than 50. Factors that contribute to the development of colorectal cancer include:
- Genetics and family history
- Lifestyle factors, like diet or smoking
- Environmental influences
The More Symptoms, the Higher the Risk
The number of colorectal cancer cases diagnosed in young people continues to rise even though cases overall have decreased. To help find out why, Fritz and colleagues looked for patterns in symptoms by analyzing health insurance data for more than 5,000 people with early-onset colorectal cancer (diagnosed under the age of 50), compared to people without a history of cancer or increased risk.
The key findings:
- People who had any of the four red-flag symptoms between three months and two years before diagnosis had a higher risk of colorectal cancer.
- Nearly half of those studied had at least one of those symptoms in the three months before diagnosis.
“We hope patients and providers are aware of the four symptoms we found to be associated with early-onset colorectal cancer,” Fritz said. “Some patients in our study had symptoms for about two years before getting a diagnosis. Early detection is critical."
The researchers also found that the more symptoms a person had, the higher their risk of getting diagnosed with colorectal cancer was. For example:
- One symptom nearly doubled a patient’s risk of the disease.
- Two symptoms increased the risk by more than 3.5 times.
- Three or more raised the risk by more than 6.5 times.
If you have symptoms like rectal bleeding or ongoing diarrhea, you should talk to your provider about getting screened for colorectal cancer, regardless of your age, said Yin Cao, ScD, MPH, a senior investigator on the study and an associate professor of surgery at the Washington University School of Medicine.
"Colorectal cancer is not simply a disease affecting older people," Cao said. “We want younger adults to be aware of and act on these potentially very telling signs and symptoms."
Getting the Right Diagnosis
Most of the early symptoms associated with colorectal cancer can also be signs of other common conditions, such as:
- Ulcerative colitis
- Crohn’s disease
- Food poisoning
- Viral gastroenteritis
“These symptoms are not specific for colon cancer. There is no specific symptom that’s related to colon cancer because there are so many other conditions that can have similar symptoms,” said Anton Bilchik, MD, PhD, a surgical oncologist and division chair of general surgery at Providence Saint John’s Health Center.
However, Bilchik said that all patients—no matter their age—should contact their healthcare provider right away if they are having symptoms to find out what’s causing them. Even if it's another condition, like hemorrhoids, it may need treatment. Other GI cancers, like stomach and pancreatic cancer, can also occur at younger ages.
Get Your Routine Colorectal Cancer Screening
If you don't have symptoms, Bilchik still recommends taking proactive measures like getting screened for colorectal cancer when you're eligible. The earlier cancer is diagnosed, the earlier treatment can start—which may lead to better outcomes. Yet only 59% of those ages 45 and older are getting their recommended screenings.
Colon Cancer Screening Guidelines
The U.S. Preventive Services Task Force (USPSTF) recommends routine colorectal cancer screening for most adults aged 45 to 75. Testing may need to be done earlier than age 45 if you’re at higher risk or have symptoms. Adults between the ages of 76 to 85 also should talk to their healthcare provider about screening.
“Younger people need to be aware that colon cancer is no longer an older person’s disease, and that it is going up exponentially among people under age 50,” said Bilchik. “There’s no excuse not to get screened.”
Different types of testing may be needed depending on your risk factors, so talk with your healthcare provider about colonoscopy and screening alternatives, like stool-based tests. Your age also may influence the treatment approaches if you’re diagnosed with colorectal cancer.
