Too Much of a Good Thing? A Cautionary Tale of Thyroid Cancer Overdiagnosis and Overtreatment

The incidence of thyroid cancer has tripled in the past four decades, with 52,890 new cases of thyroid cancer projected to be diagnosed in 2020 in the United States (1). The majority of the rise in incidence has been attributed to an increase in small low-risk thyroid cancers that have excellent prognosis (2,3). Several studies have provided evidence for thyroid cancer overdiagnosis, supported in part by the rising incidence, the large reservoir of indolent disease, and low and stable mortality rates (2,3). Cancer overdiagnosis is defined as cancer that fulfils pathological criteria for malignancy but does not lead to symptoms or death (4). This can occur either through overdetection, with identification of abnormalities that will never cause harm in a patient's lifetime, or overdefinition of disease (5). Even though the etiology of increased thyroid cancer incidence remains debated by some, the rise in imaging use, combined with increased access to health care, are thought to be major drivers in the increased detection of these indolent tumors (6–8).

The cascade of events after overdiagnosis can sometimes lead to overtreatment. Patients who are overdiagnosed may also be at risk for more aggressive treatment than what current guidelines advocate for, without conferring significant survival or recurrence benefit. For example, unnecessary surgery may predispose patients to complications such as vocal fold paralysis and hypoparathyroidism (9,10).

Because of the intricacies and possible interplay between factors influencing decision-making that can lead to overdiagnosis and subsequently overtreatment, it is not plausible to adequately answer questions about what drives these phenomena without employing complementary research methodologies. For example, quantitative studies that incorporate large cancer registries, such as the Surveillance, Epidemiology and End Results (SEER) Program or the National Cancer Database (NCDB) and those that use claims data, such as SEER-Medicare or Medicare, can provide important descriptive assessments of both overdiagnosis and overtreatment at the population level (2,7,9). In contrast, qualitative studies, such as the study by Jensen et al., incorporate semistructured interviews or focus groups of key stakeholders and can elucidate granular information on perspectives, attitudes, and beliefs that can impact disease management (11). The thematic analysis on the attitudes and beliefs of physicians and patients regarding overdiagnosis and overtreatment by Jensen et al. fills an important knowledge gap.

In summary, to better understand the role of physician and patient factors surrounding the overdiagnosis and overtreatment of low-risk thyroid cancers, Jensen et al. conducted a qualitative study using semistructured interviews with 24 endocrinologists and surgeons and 10 patients with papillary thyroid cancer <1.5 cm (11). Interview transcripts were analyzed using thematic analysis. The authors found that from the physicians' perspective, overtreatment was thought to be an issue that inevitably results from overdiagnosis, with a strong “instinctive, reflexive and habitual process” leading from thyroid nodule discovery to surgery. On the contrary, patients did not openly allude to or discuss overdiagnosis or overtreatment, but instead felt strongly that once a thyroid nodule was discovered biopsy was expected, and once they were labeled with a cancer diagnosis, surgery was inevitable. Both physicians and patients believed that having surgery after a thyroid cancer diagnosis provides peace of mind. As also shown in prior studies (12,13), this study demonstrated that patient fear and anxiety elicited by the “C word” is common and plays a pivotal role in decisions made regarding management and follow-up, irrespective of actual prognosis that is excellent in the vast majority of these patients.

Strengths of the study by Jensen et al. comprise the inclusion of both physicians and patients and the granular detailed information obtained by using qualitative methods. However, there were also limitations. One limitation is selection bias, as physicians were interviewed at a national conference attended by thyroidologists and high-volume thyroid surgeons and patients were recruited from a single academic medical institution. There is also the risk of recall bias as the patients underwent surgery within the past five years, as well as lack of participant diversity as the majority of the patients were Caucasian.

Despite limitations, this study's findings complement prior quantitative studies all the while reinforcing the need for developing approaches to curb unnecessary thyroid cancer overdiagnosis and overtreatment, with the ultimate goal of improving patients' quality of life, alleviating decisional conflict and cancer-related worry, and reducing financial toxicity associated with thyroid cancer care. In the end, we should all be cognizant that too much of a good thing may not be a good thing at all when it comes to low-risk thyroid cancers. We should all strive to uphold our promise: primum non nocere—first do no harm.

Author Disclosure Statement

No competing financial interests exist.

Funding Information

Dr. Haymart is supported by R01 CA201198 from the National Cancer Institute (NCI) and by R01 HS024512 from AHRQ. Dr. Papaleontiou is supported by K08 AG049684 from the National Institute on Aging.