Mandibular Invasion by Oral Squamous Cell Carcinoma: Clinicopathologic Features of 74 Cases

Objectives (1) For patients with oral squamous cell carcinoma (OSCC) and mandibular invasion, to determine whether prior radiation to the head and neck region (PXRTHN) affects the density of osteoblasts, osteoclasts, or fibroblasts along the tumor interface invading the mandible and whether this is significantly associated with overall survival. (2) To identify clinicopathologic features that are associated with overall survival. Study Design Case series with chart review. Setting University of Missouri hospital. Subjects and Methods Retrospective review of 74 cases with pathologically confirmed mandible invasion by OSCC and surgical treatment between January 1, 2005, and December 31, 2015. A board‐certified anatomic pathologist reviewed the slides from all mandibulectomy cases. Results The mean density of osteoclasts was 2.0 per linear mm among the patients with PXRTHN and 7.1 among those without PXRTHN ( P <. 001). Positive soft tissue frozen section margin was significantly associated with overall survival on univariate analysis ( P <. 001; hazard ratio [HR], 0.34; 95% CI, 0.19‐0.62) and multivariate analysis ( P =. 026; HR, 0.41; 95% CI, 0.19‐0.90). Maximum tumor dimension was significantly associated with overall survival on univariate analysis ( P =. 021; HR, 1.19; 95% CI, 1.03‐1.38) and multivariate analysis ( P =. 002; HR, 1.49; 95% CI, 1.16‐1.93). Osteoclast, osteoblast, and fibroblast density were not associated with overall survival. Conclusions (1) Osteoclast density along the tumor front is significantly lower among patients with PXRTHN. Stromal cell density was not associated with overall survival. (2) Positive soft tissue frozen section margin and maximum tumor dimension are significantly associated with overall survival among patients with mandibular invasion by OSCC.