Understanding the approach to interpretation and challenges in measurement of pathological depth of invasion in oral squamous cell carcinoma: A cross-sectional survey of oral and maxillofacial pathologists in India

Objectives: To understand the approach to interpretation along with challenges encountered in assessing pathological depth of invasion (pDOI) in oral squamous cell carcinoma (OSCC) as per 8 th Edition of TNM-AJCC staging among oral and maxillofacial pathologists in India. Method and Materials: A cross-sectional web-based survey was conducted (May 2021–October 2021) with a pre-validated 21-item questionnaire. Responses were stored in a Microsoft Excel worksheet and analysed by descriptive statistics using SPSS v 25.0. Results: About 69.7% of the 267 respondents correctly defined pDOI while 13.1% measured the same from tumour surface. Among those not reporting pDOI, one-third of respondents (36.6%) lacked requisite awareness about 8 th edition staging while more than half of them (55.4%) lacked proper tools to measure. The vst majority of the oral pathologists found pDOI measurement practically challenging (85.8%), mostly with difficulty in obtaining adjacent normal mucosa (77.9%). Selection of reference points of adjacent normal mucosa was divided between deepest point of rete ridge (43.1%), the closest rete ridge (28.8%) and the tip of highest submucosal papilla (15%). Conclusion: Underreporting of pDOI was observed owing to inherent challenges in measurement, thus ostensibly substituted with tumour thickness. Elaboration on reference points of adjacent normal mucosa is awaited.