Treatment of contralateral N0 neck in early squamous cell carcinoma of the oral tongue: elective neck dissection versus observation.

OBJECTIVES/HYPOTHESIS: Prophylactic treatment of contralateral N0 neck in early squamous cell carcinoma (SCC) of the oral tongue is a controversial issue. The aim of this study was to analyze the rates of occult metastases and their prognostic effects in stage I and stage II SCC of the oral tongue, and to compare the results of elective neck dissection to observation of the contralateral N0 neck in the treatment of these patients.

STUDY DESIGN: Retrospective review.

METHODS: We reviewed the medical records of 54 patients who were treated at Severance Hospital from 1992 to 2003 and had been diagnosed with stage I or stage II SCC of the oral tongue and had not received prior treatment. All patients underwent an ipsilateral elective neck dissection simultaneously with the primary lesion. The management of the contralateral N0 necks involved "watchful waiting" in 29 patients and elective neck dissection in 25 patients. Surgical treatment was followed by radiotherapy in 20 patients. Of these, seven patients belonged to the "observation" group who did not receive contralateral elective neck dissection. The follow-up period ranged from 3 to 110 months, with a mean of 56.3 months. Data were analyzed using the Kaplan-Meier method, the log-rank test, and the chi(2) test.

RESULTS: Fifteen patients (28%, 15 of 54) had occult metastases. Of these, 14 patients (26%, 14 of 54) had ipsilateral pathologic metastases. The remaining case (4%, 1 of 25) had the only contralateral level II occult neck metastasis without ipsilateral metastasis. Disease recurred in 17 of 54 patients (31%). Of these, eight cases (47%, 8 of 17) had regional recurrences. All regional recurrences developed in the ipsilateral neck; there were no cases of contralateral neck recurrence. The 5-year actuarial disease-free survival rates were 82% for the "observation" group and 68% for the elective neck dissection group. This difference was not statistically significant (P = .182). The 5-year actuarial disease-free survival rates were 83% for the "observation" group when those patients who underwent radiotherapy were excluded (n = 22) and 68% for the elective supraomohyoid neck dissection group (n = 25), which showed no statistically significant difference (P = .127).

CONCLUSIONS: This study showed that ipsilateral elective neck management is indicated for stage I and II SCC of the oral tongue. On the other hand, our series suggests that contralateral occult lymph node metastasis was unlikely in early-stage oral tongue SCC, and that there was no survival benefit for patients who underwent elective neck dissection in place of observation. Thus, it may not harmful to observe the contralateral N0 neck in the treatment of early oral tongue cancer.