Association Between Depth of Invasion and Tumor Stages in Oral Squamous Cell Carcinoma

Background: Depth of Invasion (DOI) in Oral Squamous Cell Carcinoma (OSCC) is an important factor of nodal metastasis and also aids with diagnosis, treatment planning, and prognostic assessments. The study’s objective was to find the association between DOI and Tumor Stages in OSCC patients. Method: This is a cross-sectional study. 150 histologically verified biopsies of OSCC patients were retrieved from Ziauddin Hospital’s Department of Histopathology from March 2023 to 2024. The sampling technique was consecutive. Specimens were preserved in formalin, embedded in paraffin, and stained with Hematoxylin and Eosin. Oral cancer was graded according to WHO requirements and the American Joint Committee on Cancer (AJCC) classification (TNM classification) for staging. Digital microscopic imaging determined the (DOI), as defined by the AJCC eighth edition. Statistical analysis was conducted using IBM SPSS version 24. DOI, PNI, and LVI were compared with Tumor Grade, Tumor Size, Nodal Stage, and Tumor Stage by using Chi-square/Fisher’s exact test. P-value < 0.05 is considered statistically significant. Results: Buccal mucosa (59.3%) and tongue (18.0%) were the most common sites. The majority of tumors were moderately differentiated (96.7%), with over half having a DOI >10mm (50.7%) and T4 tumor size being most prevalent (39.3%). DOI is statistically significantly associated with tumor grade (p-value = 0.011) while not significantly associated with tumor size, nodal stage, and tumor stage (p=value > 0.05). Conclusion: Our study highlights the insignificant association between DOI and tumor size, nodal stage, or overall tumor stage, but emphasizes its importance in assessing and staging OSCCC, distinguishing superficial and deeply invasive tumors, and improving patient outcomes.