Colorectal Cancer Often Diagnosed Before Recommended Screening Age

A large proportion of colorectal cancer (CRC) occurs in people under age 50, according to a new study.

“To put this in context, less than 5% of invasive breast cancers occur in women under 40—when screening typically begins,” said study author Samantha Hendren, MD, MPH, of the Center for Healthcare Outcomes and Policy, Department of Surgery, University of Michigan. “In contrast, we found that almost 15% of colorectal cancers occur before age 50—when screening begins. Since the younger patients are not being screened, their cancers are found at a worse/higher cancer stage, on average.”

In the population-based, retrospective cohort study of the nationally representative Surveillance, Epidemiology, and End Results registry for patients diagnosed with CRC from 1998 through 2011, the researchers categorized people as being younger or older than the recommended screening age. They compared the differences with regard to stage of disease at diagnosis, patterns of therapy, and disease-specific survival between age groups using multinomial regression, multiple regression, Cox proportional hazards regression, and Weibull survival analysis.

Of 258,024 patients with CRC, 37847 (15%) were <50 years. The researchers found young patients more likely to present with regional (relative risk ratio, 1.3; P<.001) or distant (relative risk ratio, 1.5; P<.001) disease. CRC patients with distant metastasis in the younger age group more likely received surgical therapy for their primary tumor (adjusted probability: 72% vs 63%; P<.001), and radiotherapy also was more likely in younger CRC patients (adjusted probability: 53% vs 48%; P<.001). Patients younger than the recommended screening age had better overall disease-specific survival (hazards ratio, 0.77; P<.001).

“We were surprised to find that younger patients’ survival matched that of the older patients, despite them being diagnosed at a worse cancer stage. This means that patients’ younger age helps them survive,” said Hendren, who also interpreted the use of surgery and radiation therapy to mean these young patients received aggressive treatment.

Hendren said she frequently hears from young CRC patients that they had symptoms for a long time before they or their medical providers considered the possibility of cancer.

“If we can raise awareness of the relatively large number of colorectal cancers in patients under age 50, perhaps some of these delays can be avoided,” Hendren stressed.

-Mike Bederka

Reference:

Abdelsattar ZM, Wong SL, Regenbogen SE, et al. Colorectal cancer outcomes and treatment patterns in patients too young for average-risk screening. Cancer. Published online January 25, 2016. doi:10.1002/cncr.29716.