[Impact of extracapsular lymph node spread in the ipsilateral neck on contralateral neck metastasis and prognosis of laryngeal cancer].

OBJECTIVE: To evaluate the impact of extracapsular lymph node spread (ECS) in the ipsilateral neck on the contralateral neck metastasis and prognosis of laryngeal cancer.

METHODS: The data of 184 laryngeal cancer patients who underwent laryngectomy and simultaneous radical or modified radical neck lymph node dissection between Jan. 1994 and Dec. 1997 were retrospectively analyzed. Of these 184 patients, 144 underwent unilateral neck lymph node dissection and 40 bilateral; 159 had supraglottic lesion and 25 transglottic. All had squamous cell carcinoma. The clinical T stage was T1 in 3, T2 63, T3 77, T4 41; N stage: NO in 123, N1 38, N2a 5, N2b 11, N2c 7. Transparent lymph node detection and continuous sectioning method were applied to all dissected neck lymph nodes. Statistical analysis was carried out using SPSS software package ( version 11.5). Survival curves were calculated through the Kaplan-Meier model. Impact of extracapsular lymph node spread in the ipsilateral neck on prognosis was assessed using the Log rank test.

RESULTS: Of these 184 patients, neck lymph node metastasis was pathologically proven in 80, 26 had ECS in the ipsilateral neck with a ECS rate of 32.5% (26/80). The ECS incidence was positively correlated with advanced pathological N stage and metastatic lymph nodes (P < 0.01). The incidence of the contralateral neck metastasis and ipsilateral neck recurrence with ECS were higher than those without ECS, which was 46.2% versus 24.1%, and 34.6% versus 7.4%, respectively (P < 0.05). The 3- and 5-year survival rates of patients with ECS were significantly lower than those of patients without ECS, which was 53.9% versus 70.4%, and 23.1% versus 57.4%, respectively (P = 0.0125).

CONCLUSION: Extracapsular lymph node spread is found to be an important prognostic factor in the laryngeal cancer. Bilateral neck dissection may be mandatory due to patients with ECS have a higher incidence of contralateral neck metastasis. The capsule of metastatic lymph nodes should be pathologically checked and reported in order to determine the extra-capsular spread status.