Multivariate predictors of occult neck metastasis in early oral tongue cancer.

OBJECTIVES: The elective dissection of cervical lymph nodes from patients with early oral tongue cancer and a clinically negative neck (T1/T2N0), remains an unsettled issue that continues to be investigated. This study examines clinical and histopathologic factors through univariate and multivariate analysis to correlate the risk of neck micrometastasis in patients with T1/T2N0 squamous cell carcinoma of the oral tongue. STUDY DESIGN AND METHODS: The clinical files and histologic sections of tumor from 45 clinically determined N0 patients were retrospectively analyzed. The factors examined include degree of tumor cell differentiation, T1/T2 staging, presence of perineural invasion, presence of angiolymphatic invasion, type of invasion front, depth of muscle invasion, and tumor thickness.
RESULTS: Independent correlates of positive occult neck metastasis included greater tumor thickness ( P = 0.01), greater depth of muscle invasion ( P = 0.01), T2 stage ( P = 0.01), poorly differentiated tumors ( P = 0.007), infiltrating-type invasion front ( P = 0.03), presence of perineural invasion ( P = 0.001), and presence of angiolymphatic invasion ( P = 0.005). The final multivariate model for estimation of an increased probability of occult neck disease included greater tumor thickness, presence of perineural invasion, infiltrating-type invasion front, poorly differentiated tumors, and T2 stage.
CONCLUSIONS: The clinical and histopathologic factors studied herein permit greater selectivity and more informed decision-making than does presurgical evaluation, when addressing elective neck treatment for early N0 oral tongue cancer. The multivariate model derived from this study appears to be a more reliable method for determining the patients most likely to benefit from elective neck dissection.