Longitudinal Analysis of Oral Potentially Malignant Disorder Conversion to Malignancy

OBJECTIVES: Oral potentially malignant disorders (OPMDs) are local and systemic conditions that can result in oral malignancies. We have had an OPMD surveillance program for 25 years covering over 30% of our state's population. More recent electronic health record search techniques have allowed us to analyze over 1500 patients in over a 10-year period, approximately 20% of total referrals. METHODS: Electronic health record (EHR) information was queried for 24 International Classification of Disease (ICD) 9 and 10 codes to generate a de-identified data set. Charts within this data set were cross-referenced against 79 ICD9/10 codes corresponding to oral and oropharyngeal cancers. The time course of conversion and frequencies of precancerous and cancerous lesions was assessed. RESULTS: Of 4496 unique patients seen, 1535 patient records met inclusion criteria. Seventy two patients showed cancerous conversion (4.69%), with 55 (3.58%) before 5 years, and 17 (1.11%) after a 5-year surveillance period. Leukoplakia and OLP patients constituted 34.7% of conversions, though other lesions/diseases of the tongue/oral mucosa showed conversion. Tongue cancers were the most represented carcinomas, followed by carcinomas of the oropharynx. CONCLUSION: We discovered overall rates of malignant conversion within the broad range reported in the world literature (0%-60%). Importantly, this living data set can be repeatedly queried over time to discover significant malignant conversions, potentially over decades. With significant conversions occurring after 5 years, OPMD conditions likely require longer-term surveillance like colon, breast, or other cancers.