Outcomes of Stage I-II Squamous Cell Carcinoma of the Oral Tongue Managed With Surgery Including an Elective Nodal Dissection: Potential Indications for Postoperative Radiation Therapy

Abstract

Patients with pathologic T1-2N0 oral tongue squamous cell carcinoma (OTSCC) are considered “low risk” and typically do not receive adjuvant treatment. We sought to characterize the outcomes of patients managed with surgery alone, their recurrence patterns, and any prognostics factors predictive of recurrence and/or survival. We retrospectively reviewed the records of 84 consecutive patients with newly diagnosed, early-stage pT1-2N0 OTSCC who underwent partial glossectomy and ipsilateral elective neck dissection from 2007-2013 at our institution. Patients who received PORT were excluded as well as those who had positive margins, pathological nodal involvement, or a history of prior or synchronous head and neck primaries. The cohort was 60% male and was comprised of 62% pT1 and 65% grade 2-3 tumors. Of the patients, 51% were current or former smokers. Median age was 58.5 (range: 20-87 years). With a median follow-up of 58 months (range: 3-131 months), 13 (16%) patients developed a relapse. The site of first relapse was isolated local in 5 patients, isolated regional in 2 patients, and combined locoregional in 6 patients. No patients developed a distant recurrence, either isolated or combined, at the time of first relapse. Regional recurrences were ipsilateral in 75% and contralateral in 25% of patients. Overall, the 5-year rates for local control (LC), regional control (RC), locoregional control (LRC), disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS) were 89%, 91%, 86%, 80%, 93%, and 87%, respectively. Pathologic T2 status was a predictor for worse outcomes across all endpoints. Perineural invasion (PNI) was a predictor for worse RC (P=.04), DSS (P=.001), and OS (P=.001). Margin ≤2 mm was a predictor for worse LC (P=.0001) and PFS (P=.0011). Nine of the 49 (18%) patients with depth of invasion (DOI) ≥4 mm suffered locoregional relapses (LRR). Of the 5 patients with pT2 and PNI, 2 (40%) developed isolated regional relapses. Of the 24 patients with pT2 and DOI ≥4 mm, 5 (21%) had regional failures. Patients who developed neck recurrences experienced a significantly worse DSS (5-year: 38% vs 100%; P<.0001) and OS (5-year: 38% vs 92%; P<.0001) compared to those who did not. All relapses underwent further salvage treatment; 8 (62%) patients were successfully salvaged with no evidence of disease at last follow-up. At our institution, patients with early-stage, pT1-2N0 OTSCC exhibited relatively low rates of LRR and good overall prognosis. Regional relapse, however, significantly impacts OS adversely. Patients with pT2 disease who have PNI and/or DOI ≥4 mm appear to be at considerable risk of regional relapse and should be counseled regarding PORT. When feasible, wider margins >2 mm should be obtained surgically.