[Neck relapse-related factors of cN0 stage supraglottic cancer]

The occult lymph node metastasis rate of supraglottic cancer is high, and the treatment of occult lymph node metastasis is important. This study was to explore the related factors, treatment, and prognosis of occult lymph node metastasis of supraglottic cancer.

Clinical data of 104 patients with cN0 supraglottic cancer, treated in Cancer Center of Sun Yat-sen University from 1992 to 1999, were retrospectively reviewed. The occult lymph node metastasis rate, distribution of metastatic lymph nodes, related factors, and treatment of the neck were analyzed.

The occult lymph node metastasis rates were 23.1% (24/104) in the whole group, and 23.9% (11/46) in stage T2 patients, 30.8% (8/26) in stage T3, 18.5% (5/17) in stage T4. The metastatic lymph nodes mainly located at lateral levels II-III(22/24). The prognosis of the patients with occult lymph node metastasis was poor (log-rank=10.66, P=0.001). Positive margin increased occult lymph node metastasis rate (Chi(2)=10.015, P=0.002), while pathologic differentiation (Chi(2)=3.349, P=0.175), T stage (Chi(2)=2.701, P=0.440), and treatment of primary lesion (Chi(2)=1.093, P=0.296) had no effects on it. Selective neck dissection reduced occult lymph node metastasis rate (Chi(2)=4.070,P=0.044).

The occult metastatic lymph nodes of cN0 supraglottic cancer mainly locate at lateral levels II-III. The prognosis of the patients with occult lymph node metastasis is poor. Positive margin increases occult lymph node metastasis rate. For patients at stage T1N0, observation is enough; for patients at stage T2-4N0, lateral neck dissection (levels II-IV) is effective.