Tool Aids in Selecting Patients With Papillary Microcarcinoma for Active Surveillance
Commentary by Senior Author R. Michael Tuttle, MD and John C. Morris, III, MD
A risk-stratified clinical decision-making framework may provide clinicians with a tool to identify which patients are most likely to benefit from an active surveillance management approach for papillary microcarcinoma, according to a paper in the January issue of Thyroid.
“I think the key is that not every papillary microcarcinoma (PMC) should automatically be offered an observational management approach,” said senior author R. Michael Tuttle, MD, Professor of Medicine and Endocrinologist, Memorial Sloan Kettering Cancer Center (MSKCC), New York, NY. “Just like all aspects of thyroid cancer, risk stratification and a careful examination of all the critical factors involved (ultrasound features, patient factors, and medical team factors) should be integrated into the formulation of the appropriate management options,” Dr. Tuttle told EndocrineWeb.
“The plan for surveillance of micropapillary thyroid cancers has become very interesting in the last 2 to 3 years, especially because of the data from these authors,” commented John C. Morris, III, MD, Professor of Medicine and Endocrinology at Mayo Clinic Rochester, and President Elect of the American Thyroid Association. “They've shown us very clearly that many patients with papillary microcarcinoma have a disease that is so indolent that it doesn’t cause any risk and in whom active surveillance is appropriate. In fact, traditional treatments for thyroid cancer like surgery—especially bilateral, total, or subtotal thyroidectomy—is likely a higher risk than the tumor itself.”
“I think the framework that these authors have outlined in this paper highlights the factors that we should be thinking about when making decisions about what treatments to recommend for this common problem,” Dr. Morris told SpineUniverse. “The framework clearly outlines those parameters that make patients better candidates, or perhaps lesser candidates, for this surveillance process.”
Rationale for Developing the Decision-Making Framework
“Over the last several years, the thyroid cancer disease management team at MSKCC has become more and more interested in an observational management approach to very low risk thyroid cancer,” Dr. Tuttle said. “This was based on both our understanding of risk stratification and the natural history of very low risk thyroid cancer, but also on the publications from our Japanese colleagues (Ito et al) that showed papillary microcarcinomas would be observed for years with serial ultrasound examinations very successfully (without the need for immediate surgery).”
“We also understood that not every patient with a papillary microcarcinoma would be an optimal candidate for observation,” Dr. Tuttle said. “For example, rarely these papillary microcarcinomas already have cervical lymph node metastases, or they are known to be growing based on previous ultrasound evaluations, or they are right at the thyroid capsule adjacent to an important structure (like the recurrent laryngeal nerve, or trachea).”
It also is important to consider patient factors—including patient preference and how compliant the patient is likely to be with follow-up—as well as factors related to the medical team—including the experience of clinicians and ultrasonographers—among other factors, Dr. Tuttle said.
How the Framework Was Developed
“After we evaluated more than 100 papillary microcarcinoma patients for possible observation (active surveillance), we began to see patterns emerge as to which patients could be observed and which patients were better off moving to immediate surgery,” Dr. Tuttle told EndocrineWeb. “Our ‘clinical framework’ was our attempt to help clinicians understand the critical factors that needed to be considered, and to place those critical factors into a table so that they could be used to help a patient and the clinician decide if they were a good candidate for observation.”
The risk-stratified approach involves evaluation of three domains:
- Tumor/neck ultrasound characteristics—primary tumor size and location, and the status of the cervical lymph nodes
- Patient characteristics—age, comorbidities, childbearing potential, family history of thyroid cancer, willingness to accept observation approach and comply with follow-up
- Medical team characteristics—availability and experience of the multidisciplinary team, quality of the neck ultrasonography, and the experience of clinician treating the thyroid cancer.
Using a table provided in the Thyroid paper, patients can be classified into one of the following three categories:
- Ideal candidate—includes older patients with probable or proven solitary PMC, well-defined nodule margins confined to the thyroid parenchyma that are not adjacent to the thyroid capsule.
- Appropriate candidate—includes possibly younger patients with multifocal disease that is adjacent to the thyroid capsule and in noncritical locations. The patients may have a potentially more aggressive molecular phenotype, or ultrasound findings that make follow-up difficult (eg, thyroiditis, nonspecific lymphadenopathy, or other benign-appearing nodules).
- Inappropriate candidate—includes patients who have tumors in critical subcapsular locations that are adjacent to or have invaded the recurrent laryngeal nerve, confirmed papillary thyroid tumors with an increase in size of ≥3 mm, or evidence of disease spread outside of the thyroid.
Dr. Tuttle developed the initial framework along with collaborator Juan P. Brito, MD, from the Mayo Clinic-Rochester, and then received input from Yasuhiro Ito, MD, PhD, and Akira Miyauchi, MD, PhD, from Kuma Hospital in Japan to modify and improve it.
An Individualized Approach to Avoiding Cytologic Confirmation of Thyroid Cancer
“I find that patients often have a hard time avoiding immediate surgery if a suspicious nodule is cytologically confirmed to be papillary thyroid cancer, no matter how small the nodule is,” Dr. Tuttle said. “I routinely offer observation without cytological confirmation of subcentimeter thyroid nodules that appear to be ideal or appropriate candidates for observation. Most patients are comfortable with that approach, while others want me to obtain a cytological diagnosis to remove the uncertainty and then make a decision regarding surgery or observation with that knowledge in hand.”
“Thus, I individualize this decision and we explore what we would do with the cytological information if we obtained it—would it change our management?,” Dr. Tuttle said. “Would it make the patient more reassured or more nervous? Would it change their decision regarding watching or surgery? After we evaluate those questions, then we decide on whether or not to obtain a cytological diagnosis.”
Patient Education Is Essential to Care
“Patients need to understand the implications, natural history, and prognosis of papillary microcarcinoma. Because our nomenclature includes the word ‘cancer’, patients become very frightened and upset,” Dr. Morris explained.
Educating patients on what surveillance entails may reassure patients, Dr. Morris added. “It is close observation. It is remeasuring and remonitoring, especially with ultrasound, over time. If at any point, there is evidence of significant change (ie, growth of at least 3 mm) or a lymph node shows up, then the patient can have surgery. All the data from the Japanese group suggests that surgery at that later in the course of the disease is as effective as surgery in the beginning. Thus, patients have nothing to lose if they chose active surveillance.
Dr. Morris concluded that more research is necessary on this topic and noted that it is unclear if the results apply to other countries. “Nevertheless, the data is so compelling and I think it is prudent to apply this framework in other countries,” he said.
February 18, 2016