Colorectal cancer (CRC) is the most common malignancy worldwide if men and women are considered together, with more than 1,200,000 new cases per year. In addition, it represents the second leading cause of cancer-related death.

CRC can be preventable as more than 85% of tumors arise in a premalignant polyp. Therefore, the aim of CRC screening is to reduce mortality by identifying individuals with presymptomatic neoplastic lesions who may require further examination and treatment. Screening tests should be workable, unexpensive, acceptable, sensitive, specific, and safe. However, none of the available recommended tests (fecal occult blood test (FOBT), sigmoidoscopy, colonoscopy, computed tomographic colonography, and faecal DNA analysis) fulfil these premises. By contrast, in first-degree relatives of patients with CRC, colonoscopy is empirically recommended from age 40 or 10 years before the age of the diagnosis of the youngest relative.

Compliance is one of the main factors influencing the success of any population-based screening program. If the test is too complicated to perform or not easily accepted by the target population, screening uptake will be poor and the effectiveness of the program will be low. In fact, this is a relevant drawback in many CRC screening programs running worldwide, with compliance rates between 25% and 67%.

The focus of this special issue will be on the different aspects related to CRC screening among average and familial-risk populations. We are interested in articles (original research papers, meta-analysis, and reviews) regarding the accuracy of noninvasive tests for detecting significant colorectal neoplasms, clinical trials comparing different screening strategies, awareness of the risk populations to be screened, barriers to CRC screening, and quality of the screening process. Potential topics include, but are not limited to:

• Diagnostic yield and optimization of screening with immunochemical FOBT and structural tests for detecting significant colorectal neoplasms
• Novel serological biomarkers and faecal DNA markers for early CRC detection
• New endoscopic techniques for improving the diagnostic yield of colorectal adenomas
• Cost-effectiveness of screening for CRC
• Knowledge, attitudes, and barriers regarding CRC screening
• Organizational aspects of population-based screening programs
• Risk factors for significant colorectal neoplasms in the familial-risk population
• Screening policy in the familial-risk population
• Postpolypectomy surveillance
• Quality of screening colonoscopy