Objectives: to describe the clinicopathologic features of oral squamous cell carcinoma in patients who develop locoregional recurrence of disease, to identify factors that predict prognosis in the subset of patients treated with salvage surgery, and to determine the adjusted effect of time to recurrence.
Design: cohort study.
Setting: a head and neck cancer institute in Sydney, New South Wales, Australia.
Patients: a total of 77 patients who underwent salvage surgery for oral squamous cell carcinoma that had been treated initially by surgery, radiotherapy, or surgery with postoperative radiotherapy.
Main outcome measures: univariable and multivariable analysis of clinical and pathologic risk factors.
Results: median time to recurrence from initial treatment was 7.5 months (range, 0.9-143.9 mo), with 86% of recurrences occurring within the first 24 months. Surgical salvage was attempted in 77 patients who had experienced recurrence at the primary site (n = 39), ipsilateral neck (n = 27), and contralateral neck (n = 11). Time to recurrence, initial treatment modality, and site of failure were independent prognostic variables.
Conclusions: the relationship of these prognostic variables displays a dynamic interaction. Initial combined-modality treatment and shorter time to recurrence were associated with worse outcome, while the effect of site of recurrence (local vs regional) was dependent on an interaction with the time to recurrence. The result of this interaction was that local recurrence was worse for those who experienced it early (eg, <6 mo after the initial treatment) and nodal recurrence was worse for those who experienced it late (eg, ≥ 6 mo after the intial treatment).