Effectiveness of screening for oral cancer and oral potentially malignant disorders (OPMD): A systematic review

Oral cancer (OC) is a debilitating disease with a high mortality rate when diagnosed in advanced stage. Conversely, early-stage OC has a high survival rate, supporting a need for early detection programmes. A previous systematic review of clinical trials evaluating efficacy of screening for OC was inconclusive. This systematic review aimed to determine the impact of screening for oral lesions on reducing mortality and incidence of OC by looking at a broader spectrum of evidence. The search for randomized controlled trials and observational studies with a control group was conducted in PubMed, OVID, Cochrane, CINAHL and grey literature sources. Risk of bias for included studies was assessed with the tools developed by the Cochrane collaboration. Six out of two identified randomized trials and five observational studies had moderate to high risk of bias. Nevertheless, the predictions on impact of OC screening on incidence and mortality were similar across the majority of the studies. The meta-analysis concluded on a 26% decrease in OC mortality, and an 19% decrease in advanced OC cases as a result of OC screening in high-risk population. Three out of four studies did not identify an impact of screening on OC incidence. No positive impact of OC screening on incidence or mortality among general population was identified in the only available randomized trial. Consistency in the outcomes and the limitations of the few available studies suggest a need for real-life setting research to evaluate the overall effectiveness of screening for OC in high-risk population.