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|Year : 2021 | Volume
| Issue : 2 | Page : 155--157
Papillary microcarcinoma—Management issues
Ashok R Shaha1, R Michael Tuttle2,
1 Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
2 Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
Ashok R Shaha
Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
|How to cite this article:|
Shaha AR, Tuttle R M. Papillary microcarcinoma—Management issues.Indian J Cancer 2021;58:155-157
|How to cite this URL:|
Shaha AR, Tuttle R M. Papillary microcarcinoma—Management issues. Indian J Cancer [serial online] 2021 [cited 2021 Sep 25 ];58:155-157
Available from: https://www.indianjcancer.com/text.asp?2021/58/2/155/315805
We are quite familiar with the rising incidence of papillary microcarcinoma all over the world. Although the exact reason behind this increase remains unclear, many researchers believe it stems from the overdiagnosis and subsequent overtreatment of this condition. Because thyroid nodules are often discovered incidentally—during routine clinical examinations, imaging studies such as magnetic resonance imaging after a car accident, carotid ultrasounds, computed tomography scans of the chest, positron emission tomography scans, and so on—the American Thyroid Association (ATA) has recommended cautious use of ultrasound-guided needle biopsy on these nodules unless they are strongly suspicious for malignancy. Even if the nodules are suspicious for malignancy but below 1 cm, the recommendation is to avoid needle biopsy. However, when there are situations where a needle biopsy has already been performed or the patient insists on a needle biopsy that leads to the diagnosis of thyroid carcinoma, then we have to make decisions about the management of these microcarcinomas.
Papillary microcarcinomas have essentially benign behavior and usually have excellent outcomes, but we do need to recognize that certain microcarcinomas are likely to be more aggressive, such as markedly irregular tumors, tumors with aggressive oncogenic mutations, or tumors in patients initially presenting with extrathyroidal extension or nodal metastasis. A small percentage of patients (<1%) may initially present with distant metastasis; tumors in these patients should be considered separately from the classical papillary microcarcinoma that we see in our everyday clinical practice. Although there continues to be considerable debate about the management of microcarcinomas, the general consensus is to consider a conservative approach. This is in contrast to the first and second guidelines of the ATA, which recommended total thyroidectomy in tumors >1 cm.,
In our own practice, although we have used 1 cm as a cutoff for observation, we have extended that cutoff to almost 1.5 cm when appropriate, and we feel very comfortable monitoring intrathyroidal papillary thyroid cancers up to 1.5 cm by active surveillance. Although there has been an overall trend in oncology practice that more (treatment) is better, when it comes to thyroid carcinoma, it is well recognized that less is more, which concludes less is better in thyroid cancer. In fact, the 2015 guidelines from the ATA included a recommendation for thyroid lobectomy as the preferred operation for low-risk thyroid papillary microcarcinoma, unless there are extenuating clinical or pathological features that would otherwise guide the operating surgeon to choose a total thyroidectomy. For example, it is essential to evaluate the opposite lobe preoperatively to make sure either there are no nodules on the other side or that they are definitely nonsuspicious and very small. If the contralateral nodule is large, a preoperative fine-needle aspiration biopsy may be performed before making an appropriate treatment decision or, if the nodules are larger than 1 cm, then total thyroidectomy should be considered so the nodules on the other side do not haunt the patient and the surgeon.
Ultimately, a high level of understanding between the surgeon, the endocrinologist who will monitor the patient, and the patient and the family is necessary to make collaborative decisions regarding the treatment and extent of surgery. It is especially important to avoid overtreatment and treatment-related medical and surgical complications, which can negatively affect a patient's quality of life and long-term outcome. Although the risk of nerve injury and hypoparathyroidism is low under the care of an experienced surgeon, it is still a major patient concern that should be addressed. If total thyroidectomy is considered a standard of care, when making treatment decisions, we also need to keep in mind the quality of life of patients, who will have to take the thyroid medication for the rest of their lives and may continue to feel unwell.
One treatment option that recognizes the slow growth of microcarcinomas is active surveillance. In Japan, Ito and Miyauchi have undertaken an observational trial using this approach, which is also known as deferred intervention. According to their series and the data from Memorial Sloan Kettering Cancer Center, approximately 3% of patients will have an increase in the size of their thyroid nodules that necessitates further surgery. Another 2% may develop nodal metastasis without any impact on the long-term outcome, and 5% of patients may change their decision to continue active surveillance because of personal fear, family involvement, and concerns about someone else suffering from aggressive thyroid cancer. The treating physicians are responsible for explaining to the patient and the family the myths about thyroid cancer treatment and modeling what care they would provide for a member of their own family. It is important to remember that it takes a lot of investment and care to make sure patients understand why we are not operating on their thyroid cancer and why we feel observation is a good option, which they have the right to change at any time. They also need to understand the common occurrence of microcarcinomas in up to 6% to 10% of normal individuals.
The Japanese group now has almost 2,500 thyroid cancer patients under observation, and a majority of them have opted for active surveillance. This overwhelming preference appears true in our thyroid cancer patients as well. We have been extremely pleased with the philosophy of active surveillance or deferred intervention at our institution and the response we have seen from patients and their families. Currently, we have more than 500 patients enrolled, and we have not had a reason to be concerned. The initial evaluation remains critical, including a dedicated ultrasound performed by an expert, followed by ultrasounds at every 6 months for the first couple of years and then once a year. It is important that the attending physician remains in close touch with the patient throughout this time so the patient does not feel neglected. As with most treatments, there are arguments for and against active surveillance, so the decision should be made by the treating physician only after careful discussion with the patient and the family.
The question is which patients are the best candidates for active surveillance? Tuttle et al. examined this critically and determined the three important factors to consider: (1) patient characteristics, (2) tumor characteristics, and (3) physician characteristics. First, the patient has to have a good understanding of the approach and should be someone who prefers minimal intervention. Second, tumors involving the isthmus, the posterior capsule, or in subcapsular locations near the recurrent laryngeal nerve are probably not the best candidates because they could grow and invade the surrounding structures. Third, both the surgeon and the endocrinologist should be available for consultation to ensure a truly multidisciplinary approach and so the patient feels they are being cared for by all specialties, not just the group interested in active surveillance.
The use of active surveillance has already been well accepted in prostate cancer, but it is not yet widely adopted in thyroid cancer. We believe more coverage of this topic in the lay press and Google search will help reach a larger number of patients. In 2014, the New York Times published an article on the rising incidence of thyroid cancer particularly in South Korea where thyroid ultrasounds were part of routine oncologic evaluations. The New York Times called this an epidemic of thyroid cancer; however, we look at this as a thyroid cancer pandemic. We need more studies and more lay press discussion about the growing incidence of thyroid microcarcinoma to help physicians and their patients make appropriate decisions about the evaluation and management of their low-risk thyroid cancer.
|1||Haugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, 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;26:1-133.|
|2||American Thyroid Association (ATA) Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer, Cooper DS, Doherty GM, Haugen BR, Kloos RT, Lee SL, et al. Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid 2009;19:1167-214.|
|3||Ito Y, Miyauchi A. Active surveillance as first-line management of papillary microcarcinoma. Annu Rev Med 2019;70:369-79.|
|4||Tuttle RM, Fagin JA, Minkowitz G, Wong RJ, Roman B, Patel S, et al. Natural history and tumor volume kinetics of papillary thyroid cancers during active surveillance. JAMA Otolaryngol Head Neck Surg 2017;143:1015-20.|
|5||Tuttle RM, Zhang L, Shaha A. A clinical framework to facilitate selection of patients with differentiated thyroid cancer for active surveillance or less aggressive initial surgical management. Expert Rev Endocrinol Metab 2018;13:77-85.|
|6||Kolata G. Study points to overdiagnosis of thyroid cancer. New York Times. November 5, 2014. Last accessed 2021 Feb 4. https://www.nytimes.com/2014/11/06/health/study-warns-against-overdiagnosis-of-thyroid-cancer.html.|