Oral squamous carcinoma: Aggressive tumor pattern of invasion predicts direct mandible invasion

Background: Aggressive histologic worst pattern of invasion (WPOI) in surrounding soft tissue has been shown to be predictive of higher local recurrence and poorer survival in oral cavity squamous cell carcinoma (OCSCC) patients. This study investigates whether aggressive WPOI can predict the mandibular invasion phenotype. Methods: Patients consecutively diagnosed with OCSCC undergoing a mandibulectomy (marginal or segmental) between 2013 and 2018 were reviewed. Senior physicians re-reviewed radiologic scans and pathologic slides of 44 cases. Results: Aggressive WPOI (WPOI-4, 5) is significantly associated with infiltrative bone invasion. Non-aggressive WPOI (WPOI-1, 2, 3) is significantly associated with the absence of bone invasion. Conclusions: WPOI has become a useful tool that further characterizes the biologic behavior of OCSCC. Potentially, planned surgery may escalate from a marginal to segmental mandibulectomy based on aggressive WPOI for patients with radiographically uncertain cortical status. Further studies are needed to validate the relationship between OCSCC WPOI and mandible status.