Compromised Outcome of Papillary Thyroid Cancer at Low-Volume Treatment Centers: Practice Makes Perfect?
Compromised Outcome of Papillary Thyroid Cancer at Low-Volume Treatment Centers: Practice Makes Perfect?
Thomas N. Wang 0
Herbert Chen 0
0 Department of Surgery, University of Alabama-Birmingham , Birmingham, AL
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.1,2 The effect of high surgeon volume accounts for the majority of the effect of high hospital volume in complex procedures.3 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.4 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.2 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.5,6 In addition, high-volume surgeons were more likely to
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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.7 They found that total thyroidectomy was
associated with a significantly higher risk of complications
compared to unilateral thyroidectomy in both low- and
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.8 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.9
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).10 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
identified many vulnerable patient populations at risk for
positive surgical margin after total thyroidectomy for
papillary thyroid cancer, including the elderly, uninsured,
and patients with government insurance. After adjusting for
patient demographic, clinical, and pathologic factors, the
authors found an association between high surgical volume
([12 thyroidectomies per year per institution) and surgical
resection success as defined by negative margin status
(odds ratio 0.72; p \ 0.01). High surgical case volume was
protective against incomplete resections. Patients with
negative margins were more likely to be younger, female,
and white, have private insurance, and receive treatment at
an academic and/or high-volume facility compared to
patients with microscopically or macroscopically positive
margins. Patients with negative margins were also more
likely to have smaller tumors and stage I disease. They
hypothesize that the elderly, the uninsured, and patients
with government insurance may present to a physician later
in their disease process with mor (...truncated)