[Retrospective study of thyroid invasion and central lymph node metastasis in 124 patients with hypopharyngeal...

Objective: To investigate the characteristics of thyroid invasion and central lymph node metastasis of hypopharyngeal carcinoma, and the impact on survival rate and quality of life. Methods: A retrospective analysis of 124 cases (122 males and 2 females with age range from 36 to 78 years old) with laryngopharyngeal squamous cell carcinoma who were initially treated in the Department of Head and Neck Surgery, Beijing Tongren Hospital Affiliated to Capital Medical University from January 2014 to December 2017 was performed. The clinical data included tumor location, pathological T stage, pathological N stage, invasion of thyroid gland, central lymph node metastasis, surgical procedures and so on. Patients were grouped according to if presence of thyroid invasion and central lymph node metastasis. With follow-up, the survival was analyzed by Kaplan-Meier method, and tumor recurrence and metastasis were evaluated. Results: Of the patients, 12 patients had thyroid involvement and 5 patients had central lymph node metastasis. The incidence of thyroid involvement was 8.16% (8/98) in pyriform sinus, 1/18 in posterior pharyngeal wall and 3/8 in posterior cricoid wall, with statistically significant difference (χ²=15.076,P=0.008). The incidence of central lymph node metastasis was 1.02% (1/98) in pyriform sinus, 3/18 in posterior pharyngeal wall and 1/8 in posterior cricoid wall, also with statistically significant difference (χ²=11.205, P=0.008). There was no statistical correlation between thyroid invasion or central lymph node metastasis and gender, smoking or alcohol exposure history and tumor pathological differentiation (all P>0.05). The 3-year overall survival rate was 80.65% and the 3-year recurrence free rate was 85.48%. Totally 24 patients died in 3 years, including 4 cases in thyroid invasion group and 1 case in central lymph node metastasis group. Local recurrence occurred in 18 patients, including 4 cases in thyroid invasion group and 1 case in central lymph node metastasis group. There was no significant difference in survival between patients with and without thyroid invasion and central lymph node metastasis (all P>0.05). There were significantly difference in 3-year overall survival and relapse-free survival among the groups with different T stages, N stages, pathological stages and tumor pathological differentiation levels (all P<0.05). There were significantly differences in the levels of serum calcium and FT3 between the groups with or without thyroid invasion and central lymph node metastasis (all P<0.05). Conclusion: The incidences of thyroid invasion and central lymph node metastasis of hypopharyngeal carcinoma are rare, and the risk of occurrence is related to the primary site of tumor. Comprehensive evaluation, correct decision-making and accurate treatment could be helpful to cure radically the tumor, to prevent recurrence and to improve the quality of life of patients.