AACE 25th Annual Scientific & Clinical Congress:

Is Less More in Thyroid Cancer Surgery?

"Less might be more when it comes to thyroid cancer surgery in 2016," said Julie Ann Sosa, MD, at the American Association of Clinical Endocrinologists (AACE) 25th Annual Scientific & Clinical Congress, May 25-29, 2016 in Orlando, Florida. In contrast, less isn't more when it comes to surgeon volumes and patient outcomes, she told the audience.

"Thyroid cancer is the fastest increasing cancer in the United States today, both in men and women, with an incidence that has exploded by nearly 300% in the last three decades," explained Dr. Sosa, who is Professor of Surgery and Medicine and Chief of the Section of Endocrine Surgery at Duke University in Durham, NC.1 Thyroid cancer was the 5th most incident cancer among women in 2013 and is anticipated to rank 3rd by 2019, overtaking both colorectal cancer and uterine cancer, Dr. Sosa said.2


"Why is this happening? There has been an explosion in diagnostic studies, both imaging studies and fine needle aspirations (FNAs). Between 2006 to 2011, the number of FNAs performed on the thyroid more than doubled," Dr. Sosa said.3 In addition to this potential surveillance bias, the increasing rate may be related to the fastest growing type of thyroid cancer diagnosis in the United States: microcarcinomas.4

Challenges in Observing Microcarcinomas
The challenges in observing microcarcinomas, Dr. Sosa said, is in identifying those tumors that are destined to become aggressive before they develop disease progression or at a point in progression at which intervention will still salvage the patient. "We also have to be able to confirm the appropriateness and safety of observation of these tiny tumors under 1 cm in size," she said.

A 2014 study by Ito et al found that older patients with low-risk papillary thyroid microcarcinomas (PTMC) were less likely than younger patients to develop disease progression and may be the best candidates for observation.5 In young patients with subclinical PTMC who do progress to clinical disease, the study suggested that it might not be too late to surgically remove the tumor and salvage the patient.

In addition, Wang et al demonstrated in 2014 that survival in patients with PTMC is equivalent to that of the general U.S. population, Dr. Sosa explained.6 "This may be because these patients have excellent access to health care, which is how the diagnosis might have been established so early," she noted. However, the study also indicated that nearly 75% of patients with PTMC underwent total thyroidectomy and nearly a third received radioactive iodine, despite the lack of evidence that this treatment translates into a survival benefit and in contrast to guideline recommendations.7

In the latest guidelines from the American Thyroid Association (ATA), the word "If" was added to the recommendation "If surgery is chosen for patients with thyroid cancer <1 cm without extrathyroidal extension and cN0, the initial surgical procedure should be lobectomy, unless there are clear indications to remove the contralateral lobe."8 The addition of "If" was significant, Dr. Sosa said, in that it suggests that surgeons don't necessarily need to choose surgery as a management strategy for PTMCs, and that observation may be appropriate if performed in an informed, compliant patient.

Lobectomy Versus Total Thyroidectomy
In the ongoing debate on the risk:benefit ratio of lobectomy vs thyroidectomy, Dr. Sosa said the belief that total thyroidectomy can be performed as safely as lobectomy is not true, based on a 2014 study by Hauch et al.9 The findings showed that, even when performed by high-volume surgeons, the rate of complications was significantly higher for total thyroidectomy as opposed to lobectomy.

She added that previous support for total thyroidectomy was largely based on a 2007 study by Bilimoria et al involving data from more than 50,000 patients in the National Cancer Database from 1985-1998, which showed an overall survival benefit with total thyroidectomy for tumors ≥1 cm.10 In fact, total thyroidectomy appeared to afford a 31% survival benefit over lobectomy alone.

"The size of this potential treatment effect was surprising to many," Dr. Sosa said. Then, in 2009, updated guidelines from the ATA recommended lobectomy for thyroid tumors <1 cm and total thyroidectomy for larger tumors.7

However, more recently, data by Nixon et al found that the two procedures had essentially equivalent outcomes at 10-year follow-up.11 In addition, a large study by Matsuzu et al with a median follow-up of nearly 18 years showed that lobectomy outcomes were comparable to some of the best outcomes with thyroidectomy from the United States, Dr. Sosa said.12

In response, Dr. Sosa and colleagues revised the Bilimoria study using the same NCDB dataset but which now has additional variables for adjustment to see if the findings held true with contemporary data.13

Patients who underwent total thyroidectomy were significantly more likely to have multifocal disease, extrathyroidal extension, nodal and distant metastases, positive surgical margins, and radioactive iodine administered. After adjusting for these variables, the survival advantage afforded by total thyroidectomy disappeared, and the survival outcomes with the two procedures became equivalent, she said.

"In part, based on that 2014 study, the ATA guidelines were adjusted in 2015 so that either total thyroidectomy or thyroid lobectomy is permitted for low to intermediate-risk-tumors," Dr. Sosa said.8

"This recommendation has been misinterpreted by many to say that the guidelines advocate for lobectomy over total thyroidectomy," Dr. Sosa said. "What this recommendation is indeed saying is that the two procedures are equivalent in terms of outcome. Therefore, the decision has to be made on an individual patient basis, based on the patient's preferences regarding relative risks and benefits."

"So in this case, less is indeed more, and more may be indeed less," Dr. Sosa noted. "I would advocate that the operation should… be formulated by the whole healthcare team, including the patient's endocrinologist, surgeon, pathologist, and radiologist, but ultimately patient preference is critical."

Impact of Surgeon Volume on Patient Outcomes
In contrast, less isn't more when it comes to surgeon experience and patient outcomes, as was demonstrated in a recent study by Dr. Sosa and colleagues.14 An analysis of data from nearly 17,000 adults undergoing total thyroidectomy showed that a surgeon volume threshold of >25 is associated with improved patient outcomes. On average, when low-volume surgeons performed total thyroidectomies, the overall complication rate was increased by an average of 55%, length of stay increased by nearly 25%, and inflation-adjusted health care costs increased by 7%.

Interestingly, three large academic institutions—Dartmouth, the University of Michigan, and Johns Hopkins University—asked their surgeons to take a "Volume Pledge," meaning that surgeons who do not perform a minimum volume of a specific procedure should stop doing those operations.

"Probably the most disturbing data I will show you is more than 51% of surgeons in the United States today who do thyroidectomy, do just one a year," Dr. Sosa noted.14 "That is the reality of where we are right now."

"Change is coming," Dr. Sosa concluded. "I think it is our job as care providers for patients with differentiated thyroid cancer to try to embrace change when change is supported by evidence, because I think it will result in superior outcomes for our patients."

 

Source
Sosa JA. F11: Thyroid Cancer Update. Thyroid Cancer Surgery in 2016. American Association of Clinical Endocrinologists (AACE) 25th Annual Scientific & Clinical Congress, Orlando, FL, May 25-29, 2016.

References
1. Davies L, Welch HG. Current thyroid cancer trends in the United States. JAMA Otolaryngol Head Neck Surg. 2014;140(4):317-322.
2. Aschebrook-Kilfoy B, Schechter RB, Shih YC, et al. The clinical and economic burden of a sustained increase in thyroid cancer incidence. Cancer Epidemiol Biomarkers Prev. 2013;22(7):1252-1259.
3. Sosa JA, Hanna JW, Robinson KA, Lanman RB. Increases in thyroid nodule fine-needle aspirations, operations, and diagnoses of thyroid cancer in the United States. Surgery. 2013;154(6):1420-1426.
4. Surveillance, Epidemiology, End Results (SEER) Program. National Cancer Institute DCCPS, Surveillance Research Program, Cancer Statistics Branch; Public-Use Database (1973–2009).
5. Ito Y, Miyauchi A, Kihara M, Higashiyama T, Kobayashi K, Miya A. Patient age is significantly related to the progression of papillary microcarcinoma of the thyroid under observation. Thyroid. 2014;24(1):27-34.
6. Wang TS, Goffredo P, Sosa JA, Roman SA. Papillary thyroid microcarcinoma: an over-treated malignancy? World J Surg. 2014;38(9):2297-2303.
7. American Thyroid Association (ATA) Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer, Cooper DS, Doherty GM, Haugen BR, et al. Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2009;19(11):1167-1214.
8. Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016;26(1):1-133.
9. Hauch A, Al-Qurayshi Z, Randolph G, Kandil E. Total thyroidectomy is associated with increased risk of complications for low- and high-volume surgeons. Ann Surg Oncol. 2014;21(12):3844-3852.
10. Bilimoria KY, Bentrem DJ, Ko CY, et al. Extent of surgery affects survival for papillary thyroid cancer. Ann Surg. 2007;246(3):375-381.
11. Nixon IJ, Ganly I, Patel SG, et al. Thyroid lobectomy for treatment of well differentiated intrathyroid malignancy. Surgery. 2012;151(4):571-579.
12. Matsuzu K, Sugino K, Masudo K, et al. Thyroid lobectomy for papillary thyroid cancer: long-term follow-up study of 1,088 cases. World J Surg. 2014;38(1):68-79.
13. Adam MA, Pura J, Gu L, et al. Extent of surgery for papillary thyroid cancer is not associated with survival: an analysis of 61,775 patients. Ann Surg. 2014;260(4):601-605.
14. Adam MA, Thomas S, Youngwirth L, et al. Is there a minimum number of thyroidectomies a surgeon should perform to optimize patient outcomes? Ann Surg. 2016 Mar 8. [Epub ahead of print]

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