Contrary to what is happening for people over fifty, rates of colon and rectal cancer are rising in younger adults.
While new colorectal cancers in older people have fallen consistently since 1985, rates for people under 50 have risen, particularly for rectal cancer.
Even more concerning, young people with colon cancer were diagnosed at later, less curable stages than those 50 or older. Almost two-thirds had a stage III or IV cancer compared to half of people diagnosed at a later age.
In the Archives of Internal Medicine, Nancy You, MD, of MD Anderson Cancer Center in Houston, and her colleagues ask, “Young-Onset Colorectal Cancer: Is It Time to Pay Attention?”
You and her team analyzed colon and rectal cancer cases in the National Cancer Database diagnosed in the ten years between 1999 and 2007.
About 1 in 10 were diagnosed before the age of 50 — 64,068 of 588,869 in the total database.
After 2001, there was an average annual increase of 2.1 percent in young onset colorectal cancer compared to a decrease of 2.5 percent yearly for those 50 and older. Rectal cancer increased even more rapidly in younger patients at an average annual change of 3.9 percent.
The median age of younger patients was 44, with 3 out of 4 (75.2 percent) diagnosed in their forties.
Cancer that had spread to either regional lymph nodes (stage III) or to distant organs (stage IV) occurred in:
- 63 percent of young colon cancer patients.
- 57.7 percent of young patients with rectal cancer
Compared to colorectal cancer in older patients, young-onset cancer occured more often in
- the rectum or the lower (distal) colon (69% vs 57.7%)
- patients who were uninsured or had Medicaid (16.5 % vs 4.7%)
- patients who lived in the south or western US (56.2% vs 50.3%)
Younger patients were also more likely to have mucinous or signet-ring subtypes and poor differentiation.
Concluding, Dr. You and her team wrote,
These data argue for heightened awareness of these concerning trends in young-onset CRC. Symptomatic young patients should undergo timely sigmoidoscopy at a minimum, if not a full colonoscopy. Identifying high-risk cohorts for targeted screening should be a priority.
What’s Behind the Trend?
Dr. You and her colleagues focused on lack of access to health care and a lack of awareness of both young patients and their doctors of the importance of symptoms of colon and rectal cancer. Commenting on their analysis, they wrote:
In the absence of routine screening, contributing factors to these trends may include
(1) a reluctance on the part of young adults to seek medical care.
(2) the large percentage of young adults without insurance or ready access to care.
(3) an underappreciation of the increasing risk for young-onset CRC, leading clinicians to overlook or dismiss symptoms that are nonspecific but may be consistent with CRC (ie, rectal bleeding, abdominal pain or cramping, change in bowel pattern).
They also commented on screening changes:
Finally, the predilection of young-onset CRCs for the distal colon and rectum identify these as high-yield anatomic regions for endoscopic evaluation in symptomatic patients and as potentially cost-effective targets for screening programs in presymptomatic young adults.
The Annual report to the nation on the status of cancer published in 2010 was concerned that diet, lack of physical exercise, and obesity may be an important factor and one that may reflect in the future for people over 50 as well.
Being overweight and failing to exercise are adverse trends that appear to increase risk for CRC, especially colon cancer. An estimated 33% of US adults are overweight, and another 34% are obese. Increasing CRC incidence among young adults (aged <50 years) may bean early indicator of the adverse impact of these risk factors.
What can young people do to reduce their risk of colorectal cancer?
Given that current analyses show that the benefits of colorectal cancer screening for average risk adults don’t begin to outweigh screening risks until age 50, young people need to:
- Maintain a healthy weight and increase physical activity.
- Reduce red meat and avoid processed meats. Eat more whole grains, fruits, and vegetables.
- Consider their family risk and get screened earlier if they have a family history of colorectal polyps or cancer.
- If they have ulcerative colitis or Crohn’s disease, follow their gastroenterologist’s directions for regular colonoscopies and biopsies.
- Know the symptoms of colon and rectal cancer and get to a doctor right away if they have any of those symptoms.
- Never accept a doctor dismissing or downplaying symptoms without a full evaluation including a colonoscopy, or, if resources are simply not there, a less costly sigmoidoscopy.
Edwards et al.,Annual report to the nation on the status of cancer, 1975-2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates., Cancer, February 1, 2010.