Surgical management around the paratracheal area of hypopharyngeal cancer

Objective: We aimed to clarify the suitable surgical management around the paratracheal area of patients who undergo total pharyngolaryngectomy based on the pathological results of hypopharyngeal cancer. Methods: The study was conducted under a multicenter, retrospective observational design in Japan. We analyzed histopathological paratracheal lymph node metastasis and thyroid invasion, and recurrence around the paratracheal area for 184 patients who underwent initial surgery among 280 participants. Results: There were significant differences in the frequency of metastasis to paratracheal lymph nodes as cN advances (P = 0.0344) and cT advances (P = 0.00028). By subsite, the paratracheal lymph node metastasis ratio was 22/130 patients (16.9%) in piriform sinus (PS), 8/32 (25.0%) in PW, 5/22 (22.7%) in PC and 10/17 (58.8%) in cervical esophagus (Ce+). The ratio of cases with bilateral paratracheal metastasis tended to be higher in cN2c, posterior wall (PW) and postcricoid (PC). Invasion to the thyroid was histopathologically confirmed in 16/184 patients (8.7%). Invasion from the primary lesion was in 15 patients. Conclusion: This study indicates that it is better for patients with advanced hypopharyngeal cancer at minimum undergo ipsilateral paratracheal lymph node dissection. Tumor subsite of PW, PC or cN2c disease or disease extending to the Ce+ should be treated with bilateral paratracheal neck dissection. In order to more reliably perform paratracheal dissection, there is also an option to resect the thyroid lobe in the range of dissection. Preservation of the thyroid gland can be considered if invasion into the thyroid gland has been clearly ruled out.