Contralateral Nodal Recurrence Rate and Prognostic Factors in Stage IVA-B Well-Lateralized Oral Cavity Cancer: A Retrospective Analysis of 120 Patients.

Abstract

For advanced-stage oral cavity cancer, literature regarding contralateral nodal recurrence was spares. Indications of elective neck dissection and elective nodal irradiation to clinically negative contralateral neck of advanced-stage well-lateralized oral cavity cancer are still debated. We aim to evaluate the contralateral nodal recurrence rate (cl-NRR) and its prognostic factors to stratify the risks. Pathologic stage IVA-B squamous cell carcinoma of oral cavity, originating from buccal mucosa, gingiva, or retromolar trigone, were retrospectively recruited from the cancer registration database of a medical center. Those who did not receive definitive surgery, with previous cancer history, or with contralateral nodal metastasis at diagnosis were excluded. All cases were staged according to AJCC 7th. From 2010 to 2017, 120 cases were enrolled, including 103 pT4 and 71 pN0. Thirty-one patients underwent contralateral neck dissection, 18 had contralateral elective nodal irradiation, and 35 received chemotherapy. After median follow up of 35.1 months, the 3-year cl-NRR was 15.7% (95% CI: 8.8 - 22.6%) as first event and was 17.7% (95% CI: 9.8 - 24.4%) for overall recurrences. The 3Y disease-free survival and overall survival were 52.8% and 63.1%, respectively. In uni-variate analysis, nodal metastasis, perineural invasion, and extracapsular extension of node were associated with higher cl-NRR. Gingival origin and poor differentiation revealed trends toward higher cl-NRR. Nodal metastasis was an independent prognostic factor for cl-NRR in multivariate analysis (pN1, HR: 12.689, p = 0.007; pN2, HR: 12.350, p = 0.005, comparing to pN0). The 3Y cl-NRR were 2.9% for pN0 (n = 71, 95% CI: 0 - 6.8%), 37.7% for pN1 (n = 11, 95% CI: 8.3 - 67.1%), and 38.4% for pN2 (n = 38, 95% CI: 19.2 - 57.6%). Advanced T stage, contralateral nodal dissection, contralateral elective nodal irradiation, and chemotherapy were not associated with cl-NRR. The contralateral nodal recurrence rate for pN0 stage IVA-B well-lateralized oral cavity cancer is low with current standard of care. However, for patient with nodal metastasis, the cl-NRR and effectiveness of contralateral elective nodal management warrant further evaluation.