Delays in Diagnosis in Primary and Secondary Care in Oral Cancer Patients: A Critical Review

BACKGROUND: Earlier diagnosis of cancers and timely treatment are associated with improved survival. In oral cancer, however, the true impact of diagnostic delays on clinical outcomes remains insufficiently understood. AIM: To perform a structured narrative review to assess the impact of delays experienced by oral cancer patients during the primary and secondary care intervals. METHODS: A systematic search was undertaken in PubMed, EMBASE, SciELO, and Scopus databases since year 2000. The study followed the PRISMA guidelines. RESULTS: The 18 studies were included; seven on Primary Care delays and 11 on Secondary Care intervals, with data from 76,954 patients. Heterogeneous definitions, arbitrary time thresholds, and diverse assessment criteria were found to describe time intervals. Up to 9.5% of patients had primary professional delay. Inaccurate treatments received in primary settings were removal of teeth (24%) and prescribing topical preparations (20%). Delays exceeding 30 days in secondary care were consistently associated with adverse survival outcomes. CONCLUSIONS: The Primary and Secondary Care intervals are measurable and modifiable components of diagnostic delay in patients with oral cancer. However, conceptual heterogeneity and limited adherence to the published guidelines restrict the ability to draw conclusions regarding the impact of these intervals on diagnostic delay and survival outcomes in oral cancer patients.