Outcomes and Prognostic Factors of Salvage Surgery for Recurrent Oral Squamous Cell Carcinoma

Background: Recurrent oral squamous cell carcinoma (rOSCC) is associated with a poor prognosis, and evidence supporting risk stratification in the salvage setting remains limited. The prognostic value of conventional staging systems and tumor-related characteristics after recurrence has not yet been fully established. Methods: We conducted a single-center observational study including patients with rOSCC who had previously undergone treatment for pT1–2 N0M0 OSCC, all subsequently surgically salvaged. Clinical, histopathological, and recurrence-related variables were collected. Recurrent tumors were classified according to the AJCC TNM staging system, the Composite Oral Cavity and Oropharynx Recurrence Staging System (CORSS), and the Same–Up–Down staging system (SUDss), a novel staging system developed by our group. Results: A total of 49 patients were included. Several pathological characteristics, including the rT3–4 category (p = 0.025), perineural invasion (p < 0.001), lymphovascular invasion (p = 0.003), greater depth of invasion (p = 0.011), nodal involvement (p = 0.002), and higher rTNM (p = 0.004) and CORSS stage (stage II p = 0.012; stage III p = 0.038) were associated with poorer OS in univariable analyses. In multivariable analysis, CORSS stage II (HR 2.89, 95% CI 1.04–8.04; p = 0.041) and stage III (HR 12.73, 95% CI 2.11–76.68; p = 0.005), as well as close/positive surgical margins (HR 2.57, 95% CI 0.99–6.71; p = 0.045) and pathological nodal involvement (HR 4.82, 95% CI 1.77–13.14; p = 0.002), were independently associated with poorer OS. Conclusions: CORSS appears to offer complementary prognostic value compared with conventional rTNM in patients with surgically treated rOSCC, although formal comparative validation of discrimination and calibration is warranted. Pathological lymph node involvement and close or positive surgical margins were the most relevant independent adverse prognostic factors. These findings identify higher-risk patients but do not, by themselves, establish a benefit from treatment intensification.