Risk factors for relapse of middle-stage squamous cell carcinoma of the submandibular region and floor of mouth: the importance of en bloc resection.

Our aim was to investigate retrospectively the rate of recurrence in the intervening region for middle-stage squamous cell carcinoma (SCC) of the tongue and identify the factors that predict relapse and prognosis. A total of 204 patients were included, 96 in the en bloc group and 108 in the control group. The groups were comparable. Two patients in the en bloc group (2%) and 12 in the control group (11%) developed recurrences in the intervening region. Kaplan-Meier analysis showed a reduction in the 5-year disease-specific survival once a recurrence had developed after the primary operation (77% compared with 14%, p<0.001). The en bloc group developed significantly fewer recurrences (2%) than the control group (11%) during the five years; p=0.037), and also had better 5-year disease-specific survival (80% compared with 66%, p=0.04). Cox's multivariate regression indicated that the pathological nodal status (p=0.016) and surgical technique (p=0.037) were independent predictive factors for the 5-year recurrence rate, as well as of 5-year disease-specific survival (p=0.001 and p=0.050, respectively). Recurrence in the intervening region is a negative prognostic factor for these patients, and we recommend en bloc resection as the management of choice for middle-stage SCC of the tongue.