- The disease should be an important public health problem in terms of its frequency and/or severity. Historically, the development of this principle was in the general context of screening for infectious and chronic diseases and not related specifically to cancer. Today some of the cancer sites considered for screening are not particularly common diseases, but, nevertheless, early detection and subsequent reduction of mortality can result in a significant benefit in life-years saved.
- The natural history of the disease presents a window of opportunity for early detection. For cancer this generally refers to a detectable preclinical phase (DPCP), and it represents the interface between characteristics of the disease and the screening technology. It is during this period that screening is considered optimal to detect the disease early and prior to the development of symptoms. For screening to be effective, the recommended screening interval must be shorter than the estimate of the DPCP.
- An effective treatment should be available that favorably alters the natural history of the disease. Usually for cancer this means a reduction in cause-specific mortality.
- The treatment should be more effective if initiated during the presymptomatic (or earlier) stage than during the symptomatic (or later) stage; that is, if treating early (presymptomatic) has no advantage over treating late (symptomatic) then the cost and the risk of screening cannot be justified.
- A suitable screening test should be available, that is, one that is accurate, acceptable to the population, fairly easy to administer, safe, and relatively inexpensive.
- There should be an appropriate screening strategy for the target population (i.e., an age to begin screening and a screening interval).
sumber:
Cancer
Principles and Practice of Oncology edisi 8
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