Anne Miles, Jill Cockburn, Robert A. Smith and Jane Wardle
Within a population, cancer screening may be organized, opportunistic, or both. Organized screening is distinguished from opportunistic screening primarily on the basis of how invitations to screening occur—organized systems issue invitations based on centralized population registers, whereas opportunistic systems issue invitations during visits for care. The current article outlined key differences between organized and opportunistic screening, including eligibility requirements, quality assurance, follow-up, attention to cost-effectiveness, evaluation, and differences in intervention research. The authors identified lessons that were learned from comparing approaches to population screening in various countries. They argued that although cancer screening is vulnerable to shortcomings at any of the numerous steps in the process, when both models are adequately resourced, organized screening is better suited to yield the fullest benefit with respect to early cancer detection.