Advancing Education, Research, and Quality of Care for the Head and Neck oncology patient.
Introduction: Head and neck squamous cell carcinoma (HNSCCa) with mandibular invasion typically requires segmental mandibulectomy to achieve negative resection margins. Final bone margin status is only available several days after the operation, and when margins are found to be positive, patients and surgeons face a dilemma in management. The situation is especially difficult when a bony free flap reconstruction is already in place. Additional bone resection is possible but the practice patterns and oncologic outcomes of re-resection are not well studied.
Methods: A multi-institutional retrospective cohort study was performed. Patients who had undergone segmental mandibulectomy with bony free flap reconstruction for HNSCCa were identified. Patients were included if they had a positive mandibular margin on final pathology report. Patient characteristics, treatments, and oncologic outcomes were recorded.
Results: Thirty-three patients from four institutions were included. All patients underwent segmental mandibulectomy and bony free flap reconstruction for HSNCCa. The most commonly used flaps were fibula (55%) and osteocutaneous radial forearm (33%). Final pathology showing positive bone margin was available on average 6.7 days after surgery (range 3-24 days). Three patients underwent additional mandible resection, with one requiring additional free flap because of initial flap failure. After surgery, 19 (58%) patients received adjuvant radiation, and 17 (52%) also received adjuvant chemotherapy. During average follow-up of 30 months, 7 patients (21%) had local recurrence, and all patients with local recurrence had simultaneous regional or distant recurrence. In total, 14 patients (42%) had recurrence over the study period. Among the three patients who underwent bony re-resection, two had local recurrence within 5 months of surgery.
Conclusion: The current study represents largest investigation of patients with positive bone margins after segmental mandibulectomy and bony free flap reconstruction. Patients do not usually undergo re-resection of mandible, and most receive additional treatment with adjuvant therapy. Although local recurrence was common, it was accompanied by additional sites of disease recurrence. Patients with positive bony margins have a pattern of aggressive disease behavior that that might not be mitigated by additional resection.