Statistically, the incidence of thyroid cancer—especially among women—has increased worldwide over the past few decades. However, researchers are unsure if this is the result of an uptick in the prevalence of thyroid cancer, or if new diagnostic tests that can detect smaller thyroid nodules has led to a possible overdiagnosis of thyroid malignancy.
Case in point: South Korea. In 2011, the rate of thyroid cancer diagnoses in South Korea was 15 times higher than in 1993. Physicians and health organizations in South Korea determined that this huge increase was due to an overdiagnosis of thyroid tumors, which can be more common than clinicians realize.
"Surgery on the thyroid has surgical risks. Some people want to avoid the risk of having to take thyroid hormone after surgery."
In 1985, researchers in Finland looked at 101 autopsies, finding that 35.6% of those examined presented incidences of occult papillary carcinomas. Of these cases, 67% had tumors under 1.0 millimeter. Researchers concluded that the vast majority of thyroid tumors remain small, and only a minimal number of these tumors will grow to become clinical carcinoma.
At Cedars-Sinai, investigators are studying the benefits of active surveillance of papillary thyroid microcarcinoma (PTMC) over immediate surgery, which is currently the standard of care for this type of thyroid cancer.
A new approach to monitoring thyroid tumors: active surveillance
Wendy Sacks, MD, endocrinologist at Cedars-Sinai, says that the case for active surveillance for PTMC arose out of clinicians questioning whether a biopsy was really necessary for these small thyroid tumors.
"Some of these tumors don't grow, they remain small," Sacks says. "The question was: Do we need to operate on all of these tumors? Could we observe them instead?"
Cedars-Sinai is one of two medical facilities in the U.S. in which patients with PTMC have the option to enroll in active surveillance. Patients can participate in an ongoing clinical trial, known as Active Surveillance of Papillary Thyroid Microcarcinoma (PMCAS), if they are diagnosed with a thyroid nodule with papillary thyroid carcinoma that measures 1.5 centimeters or smaller.
The primary objective of the study is to estimate the rate of disease progression in PTMC patients over a three-, five- or 10-year period. Patients enrolled in active surveillance can choose to have surgery at any time.
"At other hospitals, the majority of patients with PTMC just undergo surgery," Sacks says. "However, new guidelines for these types of tumors allow for certain patients to enroll in active surveillance instead."
More on the Thyroid Cancer Center at Cedars-Sinai
Quality of life concerns
As with many other types of cancer, performing surgery to excise malignant tumors is the modus operandi because, well, it works. However, in the case of patients with PTMC, there can be potential downsides to undergoing thyroid cancer surgery.
"Many studies demonstrate decreased quality of life for thyroid cancer patients, but more needs to be studied regarding the same impact on patients with micropapillary thyroid carcinomas who may have a partial thyroid resection," Sacks says.
These concerns about quality of life have led some patients diagnosed with PTMC to seek out other options.
"Surgery on the thyroid has surgical risks," Sacks says. "Some people want to avoid the risk of having to take thyroid hormone after surgery."
More on Endocrinology Research at Cedars-Sinai
Giving patients more options
On the other hand, the idea of active surveillance for a malignant tumor (even if it is small), can be a challenging concept for some patients to wrap their head around.
"Some people can't live with the idea that they have cancer and not operate on it," Sacks says.
As part of the clinical trial, patients with PTMC who opt for immediate surgery can participate in a sub-study looking at quality of life and anxiety measures.
"For patients that we diagnose, we want to give them options," Sacks says. "By monitoring patients every six months, we can catch it if the tumor grows and watch the potential spread of the disease. We can't always see the progression of the disease—there are certain blind spots we have as clinicians. However, at Cedars-Sinai, we can ensure that patients get the best multidisciplinary care available."
Read: Lifestyle and Cancer: Understanding the Connection