Surgeon volume and prognosis of patients with advanced papillary thyroid cancer and lateral nodal metastasis

Background: Surgery is the most important treatment modality for papillary thyroid cancer (PTC). However, the relationship between surgeon volume and long-term oncological outcomes has not been explored. Methods: Patients diagnosed with N1b PTC after initial thyroid surgery between 1 July 1994 and 31 December 2011 were eligible for inclusion in the study. Surgeons were categorized into high (at least 100 operations per year) and low (fewer than 100 operations per year) volume groups. Kaplan-Meier survival analysis according to surgeon volume was performed, and Cox proportional hazard modelling was used to estimate hazard ratios (HRs) with 95 per cent confidence intervals according to patient, tumour and surgeon factors. Results: A total of 1103 patients with a median follow-up of 81 (i.q.r. 62-108) months were included in the study. During follow-up, 200 patients (18.1 per cent) developed structural recurrence. A high surgeon volume was associated with low structural recurrence (P = 0.006). After adjustment for age, sex and conventional risk factors for recurrence (histology, tumour size, gross extrathyroidal extension, margin status, more than 5 positive lymph nodes, radioactive iodine therapy), the adjusted HR for structural recurrence for low-volume surgeons was 1.46 (95 per cent c.i. 1.08 to 1.96), compared with high-volume surgeons. Distant metastasis (P = 0.242) and disease-specific mortality (P = 0.288) were not affected by surgeon volume. Conclusion: Surgeon volume is associated with structural recurrence, but not distant metastasis or cancer-specific death in patients with N1b PTC. Surgeon volume is important in initial surgery for advanced PTC with extensive nodal metastasis in order to ensure curative outcome and reduce treatment-related morbidity.