Colon cancer can be difficult to diagnose, however, since symptoms can resemble those of other conditions like hemorrhoids or irritable bowel syndrome.
“Unfortunately, colon cancer doesn’t have a lot of symptoms until it’s advanced, which is why screening is so important,” said Dr. Paula Denoya, director of the Colorectal Surgery Residency Program at Stony Brook Medicine.
The pandemic also most likely delayed detection of some new cases, according to Dr. Scott Kopetz, a professor in the department of gastrointestinal medical oncology at the University of Texas MD Anderson Cancer Center.
“Patients have not had access to routine colonoscopy readily during Covid. As a result, cancers that would have been caught at an earlier stage are now presenting with more advanced and later stage,” he said.
Nearly 90% of colorectal cancer patients are age 50 or older, so doctors recommend that everyone over 45 get a colonoscopy every 10 years.
But diagnoses in younger adults have been rising: New cases of colorectal cancer went up more than 2% each year among people under 50 from 2012 to 2016, according to the American Cancer Society.
“There’s an expectation there will be 15% of colorectal cancers in people under 50 not too long from now,” said Dr. Joel Levine, co-director of the Colon Cancer Prevention Program at UConn Health.
Overall, the rate of new colorectal cancer cases in the U.S. has declined, from around 67 per 100,000 people in 1985 to around 34 in 2019, according to the National Cancer Institute.
Early signs of the disease can include rectal bleeding or changes in bowel movements such as constipation or diarrhea. Patients with more advanced illness may also experience abdominal pain, fatigue, anemia, weight loss or decreased appetite.
But Levine said people should get colonoscopies even when they feel healthy.
“One of the reasons I’m so fussy about not waiting for symptoms is because it leads to, ‘Well, I feel alright, everything’s OK.’ And by the time you have a symptom, the horse is a little bit out of the barn,” he said.