Patients high-risk for colorectal cancer benefit most from surveillance colonoscopy, according to a study published in Gastroenterology (2010 Jun;138(7):2292-9, 2299.e1).

The study, conducted by Sameer Dev Saini, MD, MS, of the Ann Arbor VA Health Services Research & Development Center of Excellence and lead author of the study, and colleagues used existing data to determine the long-term effectiveness of surveillance colonoscopy. Based on published literature, the research team developed a Markov model to study various surveillance strategies from the perspective of a long-term payer.

Researchers found that a 3/10 strategy (colonoscopy every 3 years in high-risk patients and every 10 years in low-risk patients) was more costly, but also more effective than no surveillance. Moreover, a cost-utility analysis suggested that this strategy is the optimal strategy under the vast majority of clinical circumstances.

Additional findings revealed that a 3/5 strategy (colonoscopy every 3 years in high-risk patients and every 5 years in low-risk patients) was considerably more costly, but only marginally more effective. However, compared to the 3/10 strategy, the 3/5 strategy resulted in five fewer cancers and one fewer cancer-related death per 1,000 patients entering surveillance.

A third strategy, the 3/3 strategy (colonoscopy every 3 years in both high- and low-risk patients), is cost-ineffective and potentially harmful compared to less intensive surveillance. However, compared to the 3/5 strategy, the 3/3 strategy resulted in two fewer cancers and one fewer cancer-related death per 1,000 patients entering surveillance.

The study’s authors noted that “in the future, improvements in risk stratification could further enhance physicians’ ability to target surveillance to those patients most likely to benefit from this practice.”