Lowering colorectal cancer screening age from 50 to 45 years appears cost-effective

Initiating screening for colorectal cancer (CRC) at age 45 years rather than 50 years would likely be cost-effective, but it would cost more than some alternative strategies for increasing screening rates, according to a recent study.

Researchers used a validated Markov model to study the potential impacts of the American Cancer Society's qualified recommendation to initiate CRC screening at age 45 years instead of 50 years. Their projections were based on screening participation rates in the U.S. and national age and census data. Results were published by Gastroenterology on March 28.

The study found that initiating screening colonoscopies at age 45 years averted four CRCs and two deaths due to CRC per 1,000 persons. It resulted in a gain of 14 quality-adjusted life years (QALYs) at a cost of $33,900 per QALY gained. That meets the standard to be considered cost-effective. However, this early screening strategy would require 758 additional colonoscopies per 1,000, which the study authors calculated could instead be used to screen 231 currently unscreened 55-year-olds or 342 currently unscreened 65-year-olds, through age 75 years. These alternatives would avert 13 or 14 CRC cases and six or seven deaths, gaining 27 or 28 QALYs while saving between $163,700 and $445,800.

The study also looked at the potential to use a fecal immunochemical test (FIT), followed by colonoscopies for abnormal results, and found that initiating FIT at age 45 years instead of 50 years would cost $7,700 per QALY gained.

Overall, shifting current age-specific screening rates to patients five years younger could avert 29,400 CRC cases and 11,100 deaths over the next five years, the study found. However, it would require 10.7 million additional colonoscopies and cost an incremental $10.4 billion. The authors noted that spending these resources instead to improve screening rates to 80% in those ages 50 to 75 years would avert nearly three times as many deaths at one-third the incremental cost.

“Our results suggest that given the rising CRC incidence in younger people, initiating CRC screening at age 45 is economically attractive (i.e. “cost-effective”) across a wide range of assumptions,” the authors wrote. They noted that the effects would differ if early screening were primarily conducted in healthier, lower-risk patients and that the country's capacity to provide this many additional screening colonoscopies should be considered.

The question of whether starting screening at 45 years “is desirable as national policy depends on whether it can be instituted without displacing efforts to achieve high screening participation rates in older or higher-risk persons, and whether society is willing to bear the incremental costs,” the authors said.