Recurrence interval affects survival after local relapse of oral cancer

The aim of this study was to investigate whether the recurrence interval influenced survival rate of patients with relapse of oral squamous cell carcinoma (OSCC). From 1992 to 2006, a total of 773 patients with OSCC treated at the Department of Oral and Maxillofacial Plastic Surgery of the Ruhr-University Bochum were reviewed. Statistical analysis included descriptive statistics, Kaplan-Meier survival analyses, receiver operating characteristic, the Youden-Index and analysis using the log-rank test and Cox-regression. The overall recurrence rate was 23.9%. Local recurrence was more common (64.9%) than locoregional recurrence (25.1%). Patients with relapse more than 18 months after completion of their primary treatment had significantly improved survival rates compared with those who relapsed within 18 months of initial treatment (20.5% vs 42.3%). A significant difference was noted in the survival rate between patients with local and locoregional recurrence (37.5% vs 21.5%). Overall survival rate after salvage was 31.9%. The interval from initial treatment to recurrence is an independent prognostic factor for OSCC patients. Patients with a recurrence interval of 18 months had a statistically significant higher probability of death than those with a recurrence interval >18 months. This information can help inform salvage treatment strategies and provide a classification of early and late recurrences.