Most patients who undergo thyroid surgery initially present as asymptomatic: JAMA

Dr Sajisevi and colleagues examined an important clinical question: What begins the process that eventually leads to thyroid surgery? Interestingly, most patients initially presented without any thyroid-related symptoms. These asymptomatic patients formed 4 groups: patient-requested screening, clinician-screening physician examination, radiologic serendipity, and diagnostic cascade. Within each of the 4 groups, clinical evaluation can be classified as either appropriate or inappropriate. Both patient-requested screening and diagnostic cascade may lead to inappropriate clinical evaluation with a thyroid ultrasonography. The US Preventive Services Task Force recommends against screening for thyroid cancer with ultrasonography in asymptomatic patients because of the potential for increased harms without clinical benefit. Fortunately, this study found that patient-requested screening was a rare event, although it is still occurring and leading to thyroid surgery. Diagnostic cascade, such as ordering a thyroid ultrasonography for evaluation of hypothyroidism, is also an inappropriate clinical evaluation. A thyroid ultrasonography is used to evaluate structural thyroid disease, not functional thyroid disease, such as hypo- or hyperthyroidism, but is often ordered in error for evaluation of these conditions. This, in essence, is screening for thyroid cancer. A focus on these 2 areas to address inappropriate thyroid ultrasonography would lead to fewer unnecessary thyroid surgeries.

The evaluation of thyroid incidentalomas, an incidentally seen thyroid nodule on a nonthyroid-dedicated imaging study or as the authors call it, radiographic serendipity, and an abnormal physical examination are both appropriate evaluations, yet occur in asymptomatic patients and share similarities with both screening and diagnostic cascade. The American Thyroid Association recommends a thyroid ultrasonography for the evaluation of all suspected thyroid nodules, including incidental thyroid nodules and an abnormal clinician physician examination and the American College of Radiology also recommends evaluation of incidental thyroid nodules with a formal thyroid ultrasonography.

Despite these evaluations being recommended, and therefore considered appropriate, the authors rightfully point out that these occur in asymptomatic patients and lead to a large proportion of thyroid surgeries and risk overtreatment. The most common nonthyroid-dedicated imaging study to lead to thyroid surgery was chest computed tomography, which is only becoming a more frequently ordered study because of the recommendations for lung cancer screening with chest computed tomography in current and former smokers. A more balanced approach, including a discussion of the risks and benefits with patients, is required when deciding to evaluate or not evaluate a suspected thyroid nodule found these ways.

Larger thyroid cancers have a higher stage (per the American Joint Committee on Cancer scale), are more likely to metastasize, and have worse clinical outcomes. This study found that symptomatic patients had larger thyroid tumors compared with asymptomatic patients. This is fitting because patients with larger tumors are more likely to present with symptoms. Interestingly, both groups had tumors with a mean size of more than 2 cm. Small papillary thyroid carcinomas (PTC) have historically been treated surgically, but more recent studies have shown that a watchful waiting approach to biopsy proven PTC less than 2 cm can be an appropriate treatment strategy. This nonsurgical approach to small PTCs is likely contributing to the larger tumor sizes seen in this study of patients who underwent thyroid surgery.

The authors also found regional differences in the mode of detection with South Africa and Denmark having a higher rate of patients with symptoms at presentation, while the US and Canada were more likely to perform surgery on asymptomatic patients. This difference is likely from the different health care systems in each country, providing regulation, or lack thereof, on the evaluation and treatment of thyroid pathology. This difference in practice patterns provides a unique opportunity for future research on the outcomes of thyroid cancer comparing these different approaches.

In summary, the study by Dr Sajisevi and colleagues confirms that many patients who undergo thyroid surgery initially present as asymptomatic. Despite a lack of symptoms, patients are found to have thyroid pathology, most often thyroid nodules, which begins a process that often ends with surgery and the diagnosis thyroid cancer. This aggressive evaluation and treatment cascade of asymptomatic patients is likely contributing to the overdiagnosis and overtreatment of thyroid cancer. Future efforts are required to shift toward a less aggressive process, including preventing inappropriate evaluation with screening thyroid ultrasonography and increased implementation of active surveillance protocols of small PTCs, to avoid unnecessary and inappropriate thyroid surgery.

Source: Tyler Drake, MD; Emiro Caicedo-Granados, MD; JAMA Otolaryngology–Head & Neck Surgery September 2022 Volume 148, Number 9