Background. The purpose of this study was to evaluate the incidence and predictive factors of contralateral occult lymph node metastasis in squamous cell carcinomas of the oral cavity to form a rational basis for elective contralateral neck management.
Methods. We performed a retrospective analysis of 66 patients with cancer of the N0-2 oral cavity undergoing elective neck dissection for contralateral clinically negative necks from 1991 to 2003.
Results. Clinically negative but pathologically positive contralateral lymph nodes occurred in 11% (7 of 66). Of the 11 cases with a clinically positive ipsilateral node neck, contralateral occult lymph node metastases developed in 36% (4 of 11), in contrast with 5% (3 of 55) in the cases with clinically N0 ipsilateral necks (p < .05). Based on the clinical staging of the tumor, 8% (3 of 37) of the cases showed lymph node metastases in T2 tumors, 25% (2 of 8) in T3, and 18% (2 of 11) in T4. None of the T1 tumors (10 cases) had pathologically positive lymph nodes. The rate of contralateral occult neck metastasis was significantly higher in advanced-stage cases and those crossing the midline, compared with early-stage or unilateral lesions (p < .05). Patients with no evidence of contralateral nodal cancer had significantly improved disease-specific survival over patients with any pathologically positive nodes (5-year disease-specific survival rate was 79% vs. 43%, p < .05).
Conclusions. The risk of contralateral occult neck involvement in the oral cavity squamous cell carcinomas above the T3 classification or those crossing the midline with unilateral metastases was high, and patients who presented with a contralateral metastatic neck had a worse prognosis than those whose disease was staged as N0. Therefore, we advocate an elective contralateral neck treatment with surgery or radiotherapy in patients with oral cavity squamous cell carcinoma with ipsilateral node metastases or tumors, or both, whose disease is greater than T3 or crossing the midline. V