[Risk factors for recurrence and survival analysis in locally advanced T4a papillary thyroid carcinoma after R0 resection].

To investigate the treatment outcomes and risk factors of postoperative recurrence in T4a papillary thyroid carcinoma (PTC). A total of 185 patients with locally advanced T4a PTC treated in Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2019 were retrospectively analyzed, including 127 females and 58 males, aged between 18 and 80 years, with 74 patients aged over 55 years. According to AJCC thyroid tumor staging, 111 cases were stage I (T4aN0M0 26 cases, T4aN1aM0 35 cases, and T4aN1bM0 50 cases) and 74 cases were stage Ⅲ (T4aN0M0 29 cases, T4aN1aM0 19 cases, and T4aN1bM0 26 cases). Kaplan-Meier method was used to calculate the overall survival and the recurrence-free rate, and univariate and multivariate logistic regression analyses on the clinical data were performed. Recurrent laryngeal nerve invasion was observed in 150 cases, trachea invasion in 61 cases, esophagus invasion in 30 cases, and laryngeal structure invasion in 10 cases. Postoperative follow-up periods were 24-144 months, with an average of 68.29 months. Of the 185 patients, 18 (9.73%) had recurrences or metastases, including 9 cases (4.86%) died of recurrences or metastases. The 5-year and 10-year overall survival rates were respectively 95.21% and 93.10%. The 5-year and 10-year disease-free survival rates were respectively 89.65% and 86.85%. Univariate analysis showed that age of onset, tumor diameter, preoperative recurrent laryngeal nerve palsy, esophageal invasion and cervical lymph node metastasis were the risk factors for postoperative recurrence of T4a PTC(all <0.05). Multivariate analysis showed that preoperative recurrent laryngeal nerve palsy (=3.27, 95%: 1.11-9.61, =0.032) and lateral cervical lymph node metastasis (=4.71, 95%: 1.19-18.71, =0.027) were independent risk factors for T4a PTC recurrence. Survival rate of patients with T4a PTC involving only the recurrent laryngeal nerve or the outer tracheal membrane was significantly better than that of patients with tracheal invasion (<0.05). T4a PTC patients with R0 resection can still achieve good efficacy. Preoperative recurrent laryngeal nerve palsy and lateral cervical lymph node metastasis are independent risk factor for postoperative recurrence in the patients.