Compromised Outcome of Papillary Thyroid Cancer at Low-Volume Treatment Centers: Practice Makes Perfect?

Abstract

The intimate relationship between volume and outcome for nearly every major type of surgery is ubiquitous. Highvolume hospital care is associated with significantly lower mortality rates compared to low-volume hospitals. The effect of high surgeon volume accounts for the majority of the effect of high hospital volume in complex procedures. Nobel laureate and masterful Swiss surgeon Emil Theodor Kocher recognized the importance of surgical volume in improving outcomes in thyroid surgery. Kocher reported an operative mortality rate of 13 % for his first 100 thyroid procedures. By 1912, Kocher was able to reduce his mortality rate of thyroidectomy to less than 0.5 % after performing over 5000 thyroid excisions. He demonstrated a significant reduction in operative mortality with increasing experience. In the modern era, the association recognized by Kocher between provider volume and improved patient outcome has persisted. Reames et al. demonstrated that higher-volume hospitals had significantly lower mortality rates compared to lower-volume hospitals for eight different complex procedures in over 3 million patients. Data also show a significant relationship between surgeon volume and surgical morbidity in thyroid operations. Although the majority of thyroid operations are still performed by lowvolume surgeons, national trends in thyroid surgery over the last two decades exhibit an increase in thyroid surgical procedures performed by high-volume surgeons with a decrease in the incidence of complications, specifically recurrent laryngeal nerve injury and hypocalcemia. In addition, high-volume surgeons were more likely to perform total thyroidectomy and neck dissection as compared to low-volume surgeons. Hauch et al. evaluated the Nationwide Inpatient Sample (2003–2009) of all adult patients who underwent total thyroidectomy and unilateral thyroidectomy. They found that total thyroidectomy was associated with a significantly higher risk of complications compared to unilateral thyroidectomy in both lowand high-volume surgeons; however, higher surgeon volume was associated with improved patient outcome. Mitchell et al. demonstrated that operations for thyroid cancer led to avoidable reoperations more frequently if performed at low-volume centers. The initial operations requiring avoidable reoperations included errors in judgment concerning lymph node dissection or technical errors in incomplete thyroid resection. Furthermore, Schneider and colleagues found that higher-volume surgeons had better oncologic outcomes for thyroid cancer. In this issue, Youngwirth et al. report the first study examining margin status after total thyroidectomy for papillary thyroid cancer in the National Cancer Data Base (1998–2006). A total of 31,129 adult patients with thyroid cancer met the inclusion criterion of patients who underwent total thyroidectomy. By multivariable analysis, the authors identified specific factors for patients with papillary thyroid cancer undergoing total thyroidectomy that led to a poor outcome in survival. These factors included patient factors (male gender, advanced age, African American race), socioeconomic factors (low income, government insurance), cancer stage (large tumor size, positive lymph nodes, distant metastases), absence of radioactive iodine treatment, and microscopically and macroscopically positive surgical margin status. Of these independent factors, which compromised patient survival, the authors recognized that only surgical margin status could be potentially controlled. They evaluated the factors associated with positive margin status in patients undergoing surgical resection for thyroid cancer. Their study Society of Surgical Oncology 2015