Background:
Colorectal cancer (CRC) is one of the most common cancers with a heavy burden of disease. There are several established screening-tests (fecal occult blood, flexible sigmoidoscopy, colonoscopy) with potential for early detection and sometimes prevention through the removal of pre-cancerous lesions. Recently more and more CRC-screening programs have been introduced.

Methods:
This report, based on a systematic literature search, summarizes the results of economic evaluations of cost-effectiveness of CRC-screening (5 systematic reviews, 31 primary economic evaluation studies). In addition questions about the most relevant cost aspects for planning CRC-screening are addressed and the interdependency of screening-program elements in determining cost-effectiveness is elaborated on.

Results:
The incremental cost-effectiveness ratios (ICERs) of below € 20.000 per life year gained for most screening strategies prove to be acceptable compared to the alternative "no screening". The calculated ICERs, however, vary substantially between studies. The models underlying economic evaluation require many assumptions (participation rate, sensitivity and specificity of screening tests, cost of screening, …) that are uncertain and at times unrealistic. When planning screening-programs the factors with a strong influence on costs such as additional colonoscopy capacity necessary for screening, management of screening-detected polyps and surveillance strategies or the expected participation rate need to be analyzed.

Conclusions:
From a cost-effectiveness perspective the introduction of CRC-Screening for people 50-74 years of age with average risk for CRC is justifiable based on the reviewed literature as long as screening is systematically quality assured. The choice of CRC-screening strategies is dependent on the health care system environment (infrastructure), the goals of the CRC-screening program and the additional resources available for establishing CRC-screening. For cost-effectiveness high participation rates are important. This aim needs to be balanced with assuring "informed consent" for potential participants or non-participants in CRC-screening.