Colon Cancer Screening Cost-Effective in Older Adults Veronica Hackethal, MD June 03, 2014

Colorectal cancer (CRC) screening is cost-effective in adults older than 75 years who have not had prior screening, according to a study published in the June 3 issue of the Annals of Internal Medicine.
The study is the first, according to the authors, to look at the health benefits and cost-effectiveness of CRC screening in people older than 75 years without prior screening.

“[O]ur study demonstrates that in the 23% of U.S. elderly persons without previous screening, CRC screening should be considered well beyond age 75 years,” write Frank van Hees, MSc, from the Department of Public Health, Erasmus University Medical Center, Rotterdam, the Netherlands, and colleagues. “In unscreened elderly persons with no comorbid conditions, CRC screening should be considered up to age 86 years (up to age 83 years for those with moderate comorbid conditions and up to age 80 years for those with severe comorbid conditions). Screening with colonoscopy is indicated at most ages.”

The US Preventative Services Task Force recommends screening for CRC from ages 50 to 75 years but does not recommend it for those older than 75 years who have already been screened. However, it remains unclear whether or not those without prior CRC screening should receive it after age 75 years.

Therefore, the authors used the MISCAN-Colon microsimulation model to simulate life histories and look at the health benefits and cost-effectiveness of CRC screening. Using data from observational and experimental studies, the authors constructed a cohort of 10 million previously unscreened people between the ages of 76 and 90 years, with comorbidities categorized as none, moderate, and severe. Simulations included 1-time colonoscopy, sigmoidoscopy, or fecal immunochemical test (FIT) screening.

The results suggest that the health benefits of CRC screening decreased with advanced age. Among unscreened elderly patients without comorbidities, CRC screening remained cost-effective up to age 86 years, with colonoscopy indicated up to age 83 years, sigmoidoscopy at age 84 years, and FIT at ages 85 and 86 years. Among those with moderate comorbidities, screening remained cost-effective up to age 83 years, with colonoscopy indicated up to age 80 years, sigmoidoscopy at age 81 years, and FIT at ages 82 and 83 years. Among those with severe comorbidities, screening was cost-effective up to age 80 years, with colonoscopy indicated up to age 77 years, sigmoidoscopy at age 78 years, and FIT at 79 and 80 years.

Simulations only included those at average risk for CRC, which could have limited the results. In addition, simulations did not include separate analyses for sex, race, or high-risk groups, such as those patients with a family history of CRC.

The authors explain that although the incidence of CRC increases with advancing age, screening likely does not remain cost-effective among elderly patients in their late 80s and early 90s because of their higher risk for death from other causes, as well as the risk for harm caused by colonoscopy itself. Moreover, screening at these ages could cause overtreatment, which may only add more years of medical treatment rather than prolonging life.

In an accompanying editorial, Amanda V. Clark, MD, and C. Seth Langefeld, MD, both from the Department of Internal Medicine at the University of Alabama at Birmingham, highlighted 2 main results of the study. First, those aged 76 years and older without prior screening had a prevalence of CRC that was nearly 10 times greater than in those who had negative results on screening colonoscopy at ages 50, 60, and 70 years. Second, life expectancy decreased rapidly in those older than 80 years and among those with comorbidities.

“This study has important implications regarding unscreened patients over age 75 and provides compelling evidence that these patients would likely benefit from colorectal cancer screening, preferably colonoscopy, and as close to age 75 as possible,” Dr. Clark told Medscape Medical News. “Colorectal cancer screening should be considered in every person over age 75 without fatal illness who has not had prior screening.”

Although mentioning that results from this study could help guide CRC screening decisions among elderly patients, Dr. Clark emphasized a patient-centered approach.

“One potential drawback is that [providers] will view these findings as recommendations that can be generalized to every patient,” Dr. Clark emphasized, “The decision for an older person to undergo colorectal cancer screening should be individualized, contemplating both risks and benefits in addition to the patient’s preferences and values.”

All but 1 of the authors has reported receiving grants from the National Cancer Institute during the conduct of the study. The remaining author and the editorialists have disclosed no relevant financial relationships.

Ann Intern Med. 2014;160:750-759, 804-805. Article abstract, Editorial extract