Screening and Surveillance Colonoscopy

Colorectal cancer (CRC) is the second most frequent malignant disease in Europe. Every year, 412,000 people are diagnosed with this condition, and 207,000 patients die of it. Secondary prevention of CRC consists of early diagnosis of the disease in asymptomatic individuals (screening) and long term follow up of high risk patients (surveillance). Three groups of screening methods are currently available: stool testing (guaiac or immunochemical fecal occult blood tests – gFOBT and FIT respectively and DNA tests), endoscopic examinations (flexible sigmoidoscopy and colonoscopy) and radiologic examinations (computed tomographic colonography and double contrast barium enema). Colonoscopy is therefore used as the only screening method or as a second step in case of positive results of primary screening examination (two steps screening programs). From 27 countries in the European Union, the most frequently used test is FOBT (in 11 states). There is a choice between FOBT and colonoscopy in 6 countries. FOBT and flexible sigmoidoscopy is available in Italy. Currently, the only country using colonoscopy as the only screening method is Poland. At the end of 2010, the European guidelines for quality assurance in colorectal cancer screening and diagnosis were published, summarizing the evidence based medicine data for the efficacy, the interval, the age range, the risk-benefit and cost-effectiveness of colonoscopy screening. Unfortunately, prospective randomized trial on the effect of screening colonoscopy in the reduction of CRC incidence and mortality has not been published yet. Promising should be the NordICC study, which was introduced in 2009, however the results will be available in a fifteen year period. Series of recently published studies (Canada, Germany, Poland) focusing on the interval (post-colonoscopic) cancers confirmed the inadequate protection of proximal colon by colonoscopy. Another important issue would be the quality and safety of colonoscopy and the bowel cleansing. Concerning the surveillance colonoscopy, it plays a major role in specific follow up strategies in CRC high risk groups. It can be concluded that with some limitations, colonoscopy still remains the fundamental diagnostic and prophylactic examination in colorectal cancer screening and surveillance.