1 in 7 colorectal cancers are diagnosed before screening age of 50

About 1 in 7 colorectal cancers are diagnosed before the usual screening age of 50, according to a study published online January 25, 2016, in Cancer. Patients diagnosed under 50 were also more likely to present with advanced-stage disease, but more aggressive therapy prolonged their survival, researchers noted.

These findings suggest the need for improved risk assessment and screening decisions for adults under age 50, the researchers recommended.

“Colorectal cancer has traditionally been thought of as a disease of the elderly. This study is really a wake-up call to the medical community that a relatively large number of colorectal cancers are occurring in people under 50,” said study author and colorectal surgeon Samantha Hendren, MD, MPH, Associate Professor of Surgery at the University of Michigan Medical School, in Ann Arbor, MI.

“To put this in context, breast cancer screening often begins at age 40, and less than 5% of invasive breast cancers occur in women under that age,” Dr. Hendren said. “Our study found that about 15% of colorectal cancers are diagnosed before the screening age of 50.”

Dr. Hendren and colleagues conducted this retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) cancer database to identify 258,024 patients diagnosed with colon or rectal cancer. Of these patients, 37,847 (15%) were younger than 50 years old, the recommended age to begin screening for colon cancer.

Patients under 50 were also more likely to present with regional or distant disease, and more likely to receive aggressive surgery and radiation therapy. This group also had better survival rates, both overall and by stage, the researchers found. Among patients whose cancer had spread to distant organs, 21% of patients under 50 survived beyond 5 years compared with 14% of patients 50 and older. Their improved survival could be due in part to their more aggressive treatment, the authors suggested.

These findings indicate that “we should look out for warning signs of colorectal cancer such as anemia, a dramatic change in the size or frequency of bowel movements, and dark blood or blood mixed with the stool in bowel movements,” Dr. Hendren said.

“Also, people with a positive family history for colorectal cancer (in first-degree relatives such as parents or siblings) and some others who are at higher risk should begin screening earlier than 50,” she said. “This is already recommended, but we don’t think this is happening consistently, and this is something we need to optimize.”

Dr. Hendren stopped short of advocating widespread screening at an earlier age. “[That] would be a big and costly change, and I don’t know whether it would help more people than it would hurt,” she said. “A lot of research would be required to understand this before any changes should be made.”

One change she did recommend is the need to improve resources for this growing number of younger patients who are surviving longer on more aggressive treatment. “The cancer community needs to prepare for the increasing number of very young colorectal cancer survivors who will need long-term support to cope with the physical and psychological consequences of their disease and treatments,” Dr. Hendren said.