Surgical case volume has an impact on outcomes for patients with lateral neck disease in thyroid cancer

Background — This study aimed to assess whether surgical case volume for lateral neck dissection has an impact on the survival of patients who have well-differentiated thyroid cancer (WDTC) with lateral cervical node metastases. The authors used a population-based cohort study design.

Methods — The study cohort consisted of WDTC patients in Ontario Canada who underwent thyroidectomy and lateral neck dissection. These patients were identified using both hospital- and surgeon-level administrative data between 1993 and 2017 (n = 1832). Surgeon and hospital volumes were calculated based on the number of cases managed in the year before the procedure by the physician and at the institution managing each case, respectively, and divided into tertiles. Multilevel Cox regression models were used to estimate the effect of volume on disease-free survival (DFS).

Results — A crude model without patient or treatment characteristics demonstrated that DFS was associated with both higher surgeon volume tertiles (p < 0.01) and higher hospital volume tertiles (p < 0.01). After control for clustering, patient/treatment covariates, and hospital volume, the lowest surgeon volume tertile (range, 0-20/year; mean, 6.5/year) remained an independent statistically significant negative predictor of DFS (hazard ratio, 1.71; 95 % confidence interval, 1.22-2.4; p < 0.01).

Conclusion — Surgeon lateral neck dissection case volume is a predictor of better DFS for thyroid cancer patients, with the lowest surgeon volume tertile (<20 neck dissections per year) demonstrating poorer DFS.