S1 Data -

Purpose
The growth and metastasis of solid epithelial tumors is lymphangiogenesis dependent. The most important lymphangiogenic inducers facilitating this progression is Vascular endothelial Growth Factor C (VEGF-C). The recent D2-40 (Podoplanin) antibody is specific for lymphatic epithelium and allows its objective assessment. Also, lymphovascular invasion (LVI) is a risk factor for lymph node metastases (LNM) and indicates a significant influx of tumor cells into the lymphatics, causing regional metastasis. Thus, the following study was conducted to assess and correlate VEGF-C and D2-40 immunoexpressions with clinical and histopathologic lymph node status in Oral Squamous Cell Carcinoma (OSCC) cases and also to estimate the impact of intratumoral (ILVD) and peritumoral lymphatic vessel density (PLVD) in such cases.
Methodology
A total of 128 OSCC cases, divided as Group I: Cases with clinically and histopathologically negative lymph nodes (n = 64) and Group II: Cases with clinically negative but histopathologically positive lymph nodes (n = 64) were immunoscored for VEGF-C (Anti VEGF-C antibody) (PA5-29772, Invitrogen) and D2-40 (Anti D2-40 antibody) (IR072/8072, Dako) using standard protocols. The data was statistically evaluated using STATA 18.0 with p≤0.05 considered statistically significant throughout the study.
Result
21.88% Group I cases and 40.62% Group II cases showed highest immuno-positivity for VEGF-C (p = 0.00). The mean D2-40 score for Intratumoral Lymphatic Vessel Density (ILVD) and Peritumoral Lymphatic Vessel Density (PLVD) was higher for group II cases (i.e., 41.5±13.73 and 35.95±8.27 respectively at 95% CI, p = 0.00) suggesting a direct correlation between Lymphatic Vessel Density (LVD) and LNM.
Conclusion
Lymphangiogenesis is a true determinant of the biologic potential of OSCC and obtaining an objective data in terms of LVD through D2-40 could be impactful in OSSC diagnosis and guiding treatment decisions by clinicians.