Salivary Neuropilin-1 as a Promising Biomarker in Smokers with and without Oral Leukoplakia and Oral Cancer Patients: A Clinico-Biochemical Study

Abstract Background: Neuropilin-1 (NRP1) is a transmembrane glycoprotein which has a pivotal role in pathological processes of cancer progression and metastasis. The risk of invasive oral cancer developing from oral leukoplakia is higher, ranging from 3% to 33%. Prior literature has highlighted Neuropilin overexpression in various extra oral cancers. Objective: This research analyzed salivary NRP1 levels in oral cancer in comparison with oral leukoplakia, smokers, and healthy controls. Methods: Salivary samples were obtained from 25 healthy volunteers, smokers, oral leukoplakia patients, and oral cancer patients. Enzyme-linked immunosorbent assay (My Biosource, Inc., San Diego, CA) was done to analyze salivary NRP1 enzyme levels. Significance of salivary biomarkers among different groups was assessed by ANOVA with P < 0.001 level of significance. Results: The mean salivary Neuropilin levels were 10.33 ng/ml in oral cancer patients in comparison to 7.83 ng/ml in oral leukoplakia, 5.62 ng/ml in smokers without leukoplakia, and 3.49 ng/ml in healthy controls, which was statistically significant ( P < 0.001). Conclusion: In our research, NRP1 showed a constant increase in smokers, oral leukoplakia patients, and oral cancer patients. Detection of NRP1 levels at an early stage such as smoking will act as a screening and prognostic biomarker tool, and targeted therapy against them aids to curb oral cancer initiation and progression.