Positive fresh frozen section margins as an adverse independent prognostic factor for local recurrence in oral cancer patients

OBJECTIVES: To access 1) the value of further surgical resection (completion surgery) in cases with a positive intraoperative margin analysis, and 2) whether cancers that undergo completion surgery following positive intraoperative margin analysis with subsequent negative margins should be considered true margin-negative (R0) resections in terms of adjuvant treatment planning. STUDY DESIGN: Retrospective analysis of patients with primary oral cancer. METHODS: One hundred and fifty-one patients underwent primary surgical resection of oral squamous cell carcinoma with intraoperative margin examination. In all cases for which frozen section margin analysis was positive, an extended resection was performed. Only patients with clear final margins were included in the study. RESULTS: The intraoperative analysis of surgical margins revealed that cancer-free margins were achieved in 123 cases (81.5%). In 28 specimens (18.5%), the surgical margins were positive. Local recurrence was observed in 28 (18.5%) patients, whereas regional recurrence developed in 30 (19.9%) patients. Factors significantly (P < 0.05) increased the risk of local recurrence: advanced stage of the disease (III/IV), node N-positive status, lymphovascular invasion and positive fresh frozen surgical margins. On multivariate analysis, only positive fresh frozen surgical margins remained significant independent adverse factors. CONCLUSION: Our study demonstrates that positive fresh frozen margins, regardless of re-resection to R0 status, could be a powerful adverse factor that determines an aggressive nature of the tumor. This feature should be taken into consideration in adjuvant treatment planning. The greatest impact this could have is in borderline clinical situations for which the indication for adjuvant treatment may be questionable. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1093-1098, 2018.