Outcomes of oral squamous cell carcinoma arising from oral epithelial dysplasia: rationale for monitoring premalignant oral lesions in a multidisciplinary clinic.

Surveillance of oral epithelial dysplasia results in a number of newly diagnosed cases of oral squamous cell carcinoma (SCC). The clinical stage of oral SCC at diagnosis influences the magnitude of treatment required and the prognosis. We aimed to document the stage, treatment, and outcome of oral SCC that arose in patients who were being monitored for oral epithelial dysplasia in a dedicated multidisciplinary clinic. Those with histologically diagnosed lesions were enrolled on an ethically approved protocol and molecular biomarker study. Details of clinical and pathological TNM, operation, radiotherapy, recurrence, second primary tumour, and prognosis, were recorded in patients whose lesions underwent malignant transformation. Of the 91 patients reviewed (median follow-up 48 months, IQR 18-96), 23 (25%) had malignant transformation. All were presented to the multidisciplinary team with stage 1 disease (cT1N0M0). Of these, 21 were initially treated by wide local excision, 2 required resection of tumour and reconstruction, and 2 required adjuvant radiotherapy. At follow-up 3 had local recurrence, one had regional recurrence, one had metachronous lung cancer, and 5 had second primary oral SCC. There were further diagnoses of oral dysplasia in 5 during follow-up, and it is estimated that 76% of patients will have one or other event in 5 years. Disease-specific survival was 100% and overall survival was 96% (22/23). Median follow-up after diagnosis of oral SCC was 24 months (IQR 11-58). Specialist monitoring of oral epithelial dysplasia by a multidisciplinary team allows oral SCC to be detected at an early stage, and enables largely curative treatment with simple and usually minor surgical intervention. The high incidence of second primary oral SCC in high-risk patients with oral epithelial dysplasia further supports intensive targeted surveillance in this group.