Study results argue against decisions about screening colonoscopy based on age alone
Research Activities, July 2012, No. 383
The likely value of screening colonoscopy (SC) depends not just on the age and sex of the patient, but also on the number of coexisting conditions, or comorbidities, that a person has, according to a new study. Initial guidelines for cancer screening, including SC to detect early-stage colorectal cancer (CRC), did not recommend an upper age limit for screening. In 2008 the United States Preventive Services Task Force recommended against routine SC in patients 76-85 years old, and against any screening for CRC in patients older than 85. The Task Force based its recommendations on diminishing benefit of SC with increasing age.
The new study found that taking into account the number of comorbidities affected whether a patient was likely to benefit from SC, even after accounting for age. For both men and women aged 85-94 with no comorbidities, SC is estimated to save around 100 life-years per 100,000 patients screened (65 life-years for men, 111 life-years for women). However, for men and women with at least 3 comorbidities, there were no life-years saved for patients older than 74.
The researchers used the National Cancer Institute's Surveillance, Epidemiology, and End Results database cross-referenced with the Medicare database to identify nearly 70,000 fee-for-service Medicare beneficiaries with CRC. They compared this sample with a subset of over 225,000 persons without cancer who met the same age and administrative criteria as the cancer patients to estimate the benefits and harms of SC by age, sex, and number of comorbidities. This study was funded in part by the Agency for Healthcare Research and Quality (HS17624).
More details are in "Assessing the impact of screening colonoscopy on mortality in the Medicare population," by Cary P. Gross, M.D., Pamela R. Soulos, M.P.H., Joseph S. Ross, M.D., M.H.S., and others in the December 2011 Journal of General Internal Medicine 26(12), pp. 1441-1449.