Research Groups

Early Detection and Prevention - Quality Assurance Group


Cancer screening aims to reduce the burden of disease by detecting cancer before individuals seek treatment due to self-detected signs or symptoms. For a number of cancer sites, particularly breast, cervical, and colorectal cancer, which account for approximately one of four cancer deaths worldwide, population-based screening is currently a component of cancer control applied in many high-income countries. Efforts are under way to develop screening strategies appropriate to low- and middle-income countries.

Quality assurance is of paramount importance in cancer screening because at any given time the vast majority of individuals in normal-risk populations will not have detectable disease or precursor lesions that, if left unattended, would pose a significant threat to the life or health of the individual. Thus, the accuracy of the screening process must be very high in order to correctly identify those individuals who may benefit from early detection and to avoid potentially detrimental effects of unnecessary further examinations in healthy individuals or those who will not benefit from early diagnosis and treatment.

Furthermore, the screening process comprises complex activities extending from invitation of the eligible population to performance of a screening test or tests, assessment of abnormalities, and, if necessary, treatment. Even in countries with relatively small target populations, quality-assured introduction of nationwide screening programmes may take 10 years or more due to the substantial difference between existing and required resources. International collaboration has therefore become a key factor for the successful application and further development of the standards and procedures required to maintain the effectiveness and the cost-effectiveness of screening programmes.

Experience in the European Cancer Network (ECN), which consolidated the former European cancer screening networks, has shown that achieving and maintaining high quality at every step in the screening process requires an integrated, population-based approach to health service delivery. This approach is essential in order to make secondary prevention accessible to those in the population who may benefit and in order to adequately monitor, evaluate, and continuously improve performance.

Nationwide implementation of population-based screening programmes of appropriate quality makes services performing to high standards accessible to the entire population eligible to attend screening. Large numbers of professionals undertake further specialization in order to meet the screening standards. Consequently, these nationwide efforts also contribute to widespread improvement in diagnosis and management of cancers that are detected outside of screening programmes. Therefore, improvements in quality assurance of cancer screening also have the potential to improve the entire range of cancer care.

Due to resource limitations and the need to continuously improve the effectiveness of cancer control programmes, the same fundamental principles of population-based implementation and quality assurance are increasingly being applied to cost-effective integration of complementary strategies of primary and secondary prevention.