Analysis and management of occult cervical lymph node metastasis of cN0 supraglottic laryngeal carcinoma

Abstract

Objective:To explore the rule of occult cervical lymph nodes metastasis in clinically node negative（cN0） supraglottic laryngeal carcinoma. Method:The clinical data of 185 patients with cN0 supraglottic laryngeal carcinoma were analyzed retrospectively. All patients received surgical resection of the primary lesions and lateral neck dissection. The survival curve was analyzed by Kaplan-Meier method, and the survival rate was compared by chi-square test and log rank test. Result:The total incidence of occult cervical lymph nodes metastasis in cN0 supraglottic laryngeal carcinoma was 38.9％（72／185）, the unilateral and bilateral neck occult metastases were determined in 51 cases（27.6%） and 21 cases（11.4%） respectively. A total of 266 positive nodes were collected, and the distributions of the 266 positive nodes were as follows: 220（82.7%） in level Ⅱ, 42（15.8%） in level Ⅲ, and 4（1.5%） in level Ⅳ. The occult metastasis rates of bilateral cervical lymph nodes with different degrees of differentiation were 37.5%（12/32） for poorly differentiated squamous cell carcinoma, 7.4%（6/81） for moderately differentiated squamous cell carcinoma, and 4.2%（3/72） for high differentiated squamous cell carcinoma; the occult metastasis rates of bilateral cervical lymph nodes at T1, T2, T3, T4 were 0, 2.7%（2/73）, 8.1%（6/74）, 46.4%（13/28）, respectively，and the difference was statistically significant（P<0.01）. Conclusion:cN0 supraglottic laryngeal carcinoma has a high rate of occult cervical lymph nodes metastasis, and its metastatic area is mainly located in level Ⅱ-Ⅲ, so the primary tumor of the laryngeal carcinoma and the neck lymph node of level Ⅱ-Ⅲ should be managed at the same time. For the cN0 patients with poorly differentiated squamous cell carcinoma or T4 staging should be treated with bilateral neck dissection.