Prognostic factors in patients with persistent/recurrent differentiated thyroid carcinoma after comprehensive treatment.

Objective: To investigate the prognostic factors of patients with persistent/recurrent differentiated thyroid carcinoma (DTC) especially with external invasive persistent recurrent DTC after comprehensive treatment. Methods: The clinical data of 525 patients with persistent/recurrent DTC who underwent surgical treatment from August 2011 to June 2021 in the Department of Head and Neck Surgery of Jiangsu Cancer Hospital were retrospectively analyzed. The prognostic factors affecting overall survival (OS) and relapse-free survival (RFS) of persistent/recurrent DTC, especially external invasive persistent/recurrent DTC were analyzed. Results: Among 525 patients, 318 patients underwent thyroidectomy, 359 patients underwent central lymph node dissection, and 409 patients underwent lateral cervical lymph node dissection. Among 493 followed-up patients, 5-year OS and RFS were 95.10% and 89.60%, 8-year OS and RFS were 91.80% and 81.30%. Cox regression analysis showed that in patients with persistent/recurrent DTC after comprehensive treatment, age ≥55 years at reoperation after recurrence, male gender and distant metastasis were independent risk factors of OS (all P<0.05); while the simultaneous invasion of thyroid and lymph nodes, multiple organ invasion and the number of previous operations ≥2 were independent risk factors of RFS (all P<0.05). In patients with external invasive persistent/recurrent DTC after comprehensive treatment, age ≥55 years at reoperation after recurrence and male gender were independent risk factors of OS (both P<0.05); while multiple organ invasion and the number of previous operations ≥2 were independent risk factors of RFS (both P<0.05). Conclusions: Male patients aged 55 years old and above, with distant metastasis have a higher risk of poorer prognosis in persistent/recurrent DTC; while patients with simultaneous external invasion of thyroid and lymph nodes, multiple organ invasion and the number of previous operations ≥2 are more likely to relapse. For external invasive persistent/recurrent DTC, male patients aged 55 years old and above have a higher risk of poorer prognosis; while patients with multiple organ invasion and the number of previous operations ≥2 are more likely to have recurrence.