Abstract
OBJECTIVE: To compare circulating tumor DNA (ctDNA) levels between patients with oral squamous cell carcinoma (OSCC) and healthy controls. METHODS: A case-control study was conducted at Khyber College of Dentistry and Khyber Medical University, Peshawar. A total of 124 participants (94 OSCC patients and 30 healthy controls) were recruited using a non-probability consecutive sampling technique after obtaining the written informed consent. ctDNA was extracted from plasma and quantified using Qubit fluorometry and Nanodrop spectrophotometry. Real-time polymerase chain reaction (PCR) with TaqMan probes was used for detection. Independent t-tests compared ctDNA levels between OSCC patients and controls, and linear regression was conducted to assess the influence of age, gender, tumor site, and histopathological grade on ctDNA levels. RESULTS: The mean age of OSCC patients (56.82 ± 11.92 years) was significantly higher than that of controls (31.93 ± 7.10 years, p < 0.001). The most common tumor site was the buccal mucosa (20.16%), and moderately differentiated OSCC was the most prevalent histopathological grade (38.71%). The mean ctDNA level was significantly higher in OSCC cases (37.52 ± 8.71 ng/ml) compared to controls (11.00 ± 6.39 ng/ml, p < 0.001). Linear regression analysis confirmed significantly elevated ctDNA levels in OSCC cases (β = 28.13, 95% CI: 19.67–36.60, p < 0.001). Age, gender, tumor site, and histopathological grade did not significantly influence ctDNA levels. CONCLUSION: OSCC patients exhibited significantly higher ctDNA levels than healthy controls. ctDNA quantification may serve as a promising non-invasive biomarker, though further validation is needed.