Comparison of primary care doctors and dentists in the referral of oral cancer: a systematic review

Oral cancer is referred to specialists by both general practitioners (GPs) and dentists, with varying proportions reported in different studies. However, some have noted that dentists more commonly refer oral cancer in the absence of patient-perceived symptoms and may refer at an earlier stage. Unfortunately, approximately half the UK adult population do not receive regular dental care. We have conducted a systematic review of studies that compare GPs and dentists in the referral of oral cancer and have focused on three aspects: the proportion of diagnosed oral cancers, stage on presentation, and delay. Searches of the databases Medline, Embase, Scopus, Google Scholar, Web of Science, and CINAHL, together with additional searches of reference lists, authors, and conference proceedings, found 22 studies from 10 countries, which included a total of 4953 oral cancers. The percentage of medical referrals ranged from 13% to 86%; dental referrals ranged from 15% to 80%. Random-effects meta-analysis indicated a combined relative risk of medical referral to dental referral of 1.36 (95% CI: 0.99 to 1.86). For UK-based studies, the relative risk was also 1.36 (95% CI: 1.05 to 1.76). There was considerable heterogeneity for all studies and for a subgroup of UK studies: I²96.4% (95% CI 95.4 to 97.1) and 81.0% (95% CI 63.3 to 90.1), respectively. Several studies showed a lower stage for dentally-referred cancers; the combined risk for dentists and GPs referring early (stages 1 and 2) disease was 1.37 (95% CI: 1.17 to 1.60), and one cause may be the much higher number of cases referred by dentists in the absence of symptoms. No studies showed a significant difference in delay. Oral cancer is referred by both GPs and dentists, typically about 50% and 40%, respectively, although there is a wide range, probably depending on local circumstances. Both groups require skills in oral examination, recognition of lesions, and knowledge of the risk factors. Effectively, regular dental attenders are a select group that is regularly screened for oral cancer, and it is likely that screening is not delivered to those with the highest risk. We suggest that further work is required on how to access high-risk individuals both for possible screening and preventive interventions.