Potential New Focus for Colorectal Cancer Screening

A new study has found that screening tests for colorectal cancer have mostly focused on older, sicker patients for years, but future tests should be directed more toward younger, healthier patients.

Researchers from four Veterans Affairs’ (VA) Medical Centers set out to discern—in “patients 70 years or older who had an outpatient visit at 1 of 4 VA medical centers in 2001 or 2002 and were due for screening”—whether colorectal cancer screenings were more often targeted toward older, unhealthy patients who were not expected to live past the next five years. The Veterans Health Administration, the American Cancer Society, and the American Geriatrics Society currently recommend the tests for older patients without significant health risks, according to the published results of the study in a recent issue of Annals of Internal Medicine.

According to the results, only 47% of patients with no comorbidities were tested for colorectal cancer, despite expectations that they would live beyond five years. Though the rate of screening tests performed went down as age and pre-existing health problems increased, 41% of patients with comorbidity were tested for colorectal cancer.

The study’s primary outcome was determined by “fecal occult blood testing (FOBT), colonoscopy, sigmoidoscopy, or barium enema in 2001 or 2002, on the basis of national VA and Medicare claims.” In addition, researchers used Charlson-Deyo comorbidity scores, taken in 2001, to “stratify patients into 3 groups ranging from no comorbidity (score of 0) to severe comorbidity (score ≥4), and 5-year mortality was determined for each group.”

The authors said that the patterns they saw with colorectal screenings and age and comorbidity were also seen in other health-related tests, such as mammography, Pap smears, and prostate-specific antigen screening.

The researchers suggest sicker patients seeing doctors more frequently as one reason for the disparity. They also caution that generalizing about colorectal screenings outside the VA system is uncertain, because their study cohort was primarily men who used this system for their healthcare.

The researchers concluded that colorectal screenings could be better focused, based on comorbidity and age factors, and that cancer screening guidelines should be “more explicit about which combinations of age and comorbidity identify older patients who have substantial life expectancies and those who are likely to die within 5 years.” This, in turn, would help physicians use these factors and “clinical judgment” to make better decisions about the potential risks and benefits of screening tests in older people.