The Option of Active Surveillance
Whether to choose active surveillance or immediate intervention for certain low-risk thyroid cancers can be a difficult decision, but it’s an option that is being taken increasingly seriously in the face of data showing the benefits. “At first glance,” said Marilene Wang, MD, professor of otolaryngology–head and neck surgery at the University of California, Los Angeles, “this concept seems to fly in the face of every oncologic principle that we know.
Early diagnosis and timely treatment have always been the standards for best practice management of cancer.”
Explore this issue:March 2019
But the evidence is hard to ignore. In the last three decades, the incidence of thyroid cancer diagnoses has almost tripled, but the death rate hasn’t changed, according to the latest data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program. That, Dr. Wang said, is because many of these cancers that account for the increased incidence are very small papillary microcarcinomas found on routine ultrasound.
The American Thyroid Association 2015 guidelines say that very low-risk tumors “can be” considered for active surveillance—based on two Japanese studies that followed patients for a decade and found low frequency of enlargement and no recurrence or death after surgery when progression was discovered.
More recently, Memorial Sloan Kettering researchers found that, among 291 patients who underwent active surveillance for a median of 25 months, growth of 3 mm or more was seen in just 3.8% of patients, with no regional or distant metastases seen during surveillance. They also found that 3D measurements of tumor volume were better at finding growth than tumor diameter, discovering it a median of 8.2 months earlier. (JAMA Otolaryngol Head Neck Surg. 2017;143:1015–1020).
Nonetheless, SEER data for 1998 to 2010 show that 98% of those with papillary thyroid microcarcinoma undergo surgery, and 75% receive a total thyroidectomy.
Active surveillance is a good option, said Dr. Wang, when only patients considered low-risk are selected, when a multi-disciplinary team with a high level of expertise is available, and when patients are compliant.
A study out of Kuma Hospital in Japan found that the cost of immediate surgery was 4.1 times higher than surveillance even with the costs of salvage surgery for recurrence factored in (Endocr J. 2017;64:59–64).
The level of patient anxiety also is a big factor, Dr. Wang said. “If the patient is highly anxious and they’re going to live a long time, it’s probably better for them to have a hemithyroidectomy,” she said. “If they don’t have much anxiety and their life expectancy is not great, hemithyroidectomy is probably not cost-effective.”