Malignant Transformation Rate of Oral Premalignant Disorders: A Large Database Analysis

Oral leukoplakia (OL), oral lichen planus (OLP), and oral submucous fibrosis (OSF) are precancerous lesions known to progress to oral squamous cell carcinoma (OSCC). The transformation rates to OSCC are controversial and have been based on small, heterogeneous, single-institution studies. We present the largest study to date looking at the malignant transformation rates of these oral premalignant disorders (OPMD).

We conducted a retrospective cohort study within the TriNetX database. Patients aged ≥ 18 with a diagnosis of OL, OLP, and OSF between 2008 and 2018 were included, allowing for up to 5 years of follow-up. The primary outcome was the 5-year rate of OSCC transformation compared to a control cohort. Secondary outcomes included treatment pathways and survival. Descriptive and comparative statistics were conducted using TriNetX software.

Totally, 59,204 patients with diagnosed OL, OLP, or OSF were included. The average age of all included patients was 55.8 ± 14.1; the majority were female (n = 31,805, 53.7%) and white (n = 33,867, 57.2%). Rates of nicotine and alcohol dependence were 8.7% and 2.8%, respectively. The 5-year malignant transformation rates of OL, OLP, and OSF were 15.6%, 1.4%, and 18.6% (p < 0.01 compared to control), with an overall malignant transformation rate of 6.2% (p < 0.01 compared to control). The 5-year Kaplan-Meier survival probability was 94.3%.

Our results indicate the rates at which patients with OPMD (OL, OLP, and OSF) progress to OSCC are higher than previously reported. Transformation rates for OL and OSF in particular underscore the need for close monitoring and prompt treatment to avoid malignant transformation.

Retrospective cohort study-Level 3.