Primary Tumor Thickness as a Risk Factor for Contralateral Cervical Metastases in T1/T2 Oral Tongue Squamous Cell Carcinoma

Objectives/Hypothesis: Contralateral cervical metastases represent an avoidable source of failure in squamous cell carcinoma (SCCa) of the oral tongue. We sought to identify risk factors for the development of contralateral cervical metastases in T1/T2 oral tongue SCCa. Study Design: Retrospective review. Methods: We reviewed the medical records of 50 sequential cases of Stage I/II SCCa of the oral tongue treated with surgery between 1983 and 2003 at Loyola University Medical Center and Hines VA Hospital. Clinical staging, primary tumor thickness, results of neck dissection, adjuvant treatment, site and date of recurrence, and final outcome were recorded. Follow-up ranged from 0.2 to 17 years, with a mean of 5 years. Data were analyzed using multivariate logistic, Cox regression analysis, and a classification and logistic regression tree analysis. Results: The odds ratio for risk of developing contralateral neck metastasis was 5%, for each 1 mm increase in tumor thickness (P = .68). The risk did not change when controlling for the presence of ipsilateral metastasis. There was a significant relationship between contralateral cervical metastases and the development of recurrent disease at any site (P = .005). Classification tree analysis determined the risk for contralateral. metastases and was greatest for patients with tumors >3.75 mm thick and <= 9.5 mm. thick. Conclusions: This report is the first to our knowledge that evaluates thickness as a risk factor for contralateral cervical metastasis in oral tongue SCCa. We recommend consideration be given to treating the contralateral neck in cases where the primary tumor is >3.75 mm thick.