The American Cancer Society (ACS) recently lowered their recommended starting age for colon cancer screening to age 45 for people with an average risk of colon cancer. That is five years earlier than the ACS had previously recommended. While no other health organizations have lowered their recommended starting age, the ACS says they decided to make the change in their latest guidelines because of increasing rates of colon cancer among younger people in recent years.
The ACS made its decision after reviewing data from a major analysis by staff researchers. The data showed that new cases of colon cancer are occurring at an increasing rate among younger adults. Experts on the ACS Guideline Development Group determined that beginning screening at age 45 for adults of average risk for colon cancer will result in more lives saved.
Authors of the guideline say that "lowering the starting age is expected to benefit not only the segments of the population who suffer disproportionately from [colon cancer]—blacks, Alaska Natives, and American Indians—but also those individuals otherwise considered to be at average risk."
People at average risk for colon cancer include those who have:
- No personal history of polyps or colon cancer
- No family history of colon cancer
- No personal history of inflammatory bowel disease (e.g., Crohn disease, ulcerative colitis)
The incidence of colon cancer has decreased over the last twenty years in people age 55 and older due in part to screening that results in the removal of cancerous and precancerous polyps. However, there has been a 51% increase in colon cancer among people younger than age 50 since 1994. Lately, deaths from colon cancer in this age group have also begun to rise. A recent analysis also found that adults born around 1990 have twice the risk of colon cancer and four times the risk of rectal cancer compared with adults born around 1950, who have the lowest risk. (The rectum is connected to the colon and screening detects cancer in the rectum too.) However, the reason for the increase is not yet understood, according to the new guidelines.
The ACS guidelines do not prioritize a particular screening test—there are several tests that can detect precancerous polyps and/or colon cancer—and instead says patients and their healthcare practitioners should choose from among several tests based on the patient's preference. How often to be tested depends on which test the patient chooses. Options include:
If a test other than a colonoscopy indicates a possibility of cancer, that should be followed up with a colonoscopy as soon as possible.
"Given the evidence that adults vary in their test preferences, we believe that screening rates could be improved by endorsing the full range of tests without preference," says Elizabeth T. H. Fontham, DrPH, Emeritus Professor and Founding Dean of LSU Health New Orleans School of Public Health and Co-Chair of the American Cancer Society's Guideline Development Group. "People should have a conversation with their physicians to decide which type of screening is best for them."
People at increased or high risk of colon cancer—because of a family or a personal history of colon cancer, inflammatory bowel disease, previous radiation to the abdomen or other conditions that increase the risk of colon cancer—might need to start screening before age 45 and be screened more often, typically with a colonoscopy.
The new guidelines also recommend that after age 75, people discuss the need for screening with their physician. After age 85, there is no longer a need for colon cancer screening, according to the ACS.