Impact of treatment sequence of multimodal therapy for advanced oral cavity cancer with mandible invasion. 
To determine the effect of treatment sequence of multimodal therapy for clinically advanced squamous cell carcinoma (SCC) of the oral cavity (OC) with mandible invasion.  Case series with chart review.  University-based, tertiary care hospitals.  The authors retrospectively analyzed 70 patients presenting between January 2000 and January 2010 with newly diagnosed, previously untreated SCC of the OC with mandible invasion that we deemed resectable (stages IVa, b).  Patients with evidence of distant metastases or a second primary malignancy were excluded.  All patients were presented at a multidisciplinary tumor board for prospective planning of trimodality therapy (surgery, radiation therapy, chemotherapy).  When performed, surgery included segmental mandibulectomy.  Radiotherapy was delivered using standard intensity-modulated radiation therapy technique.  Study patients were divided into 2 groups: group 1 received induction chemotherapy and/or concurrent chemoradiation followed by surgery, and group 2 was treated with primary resection followed by chemoradiation.  Progression-free survival (PFS).  Eighteen patients (26%) comprised group 1, and 52 patients (74%) comprised group 2.  The groups were matched in oral cavity subsite, tumor differentiation, tumor characteristics of aggressiveness (perineural and lymphovascular invasion), extent of mandible invasion, and cervical node status.  The 5-year PFS for group 1 (33.3%) was not significantly different from that for group 2 (32.3%; P = .643).  Advanced OC cancer with mandible invasion is an ominous disease.  Although treatment must be individualized, our data suggest no clear advantage to any specific sequence of multimodality therapy affecting PFS.