About 41% of patients who underwent surgeries for thyroid nodules had asymptomatic nodules. According to a new study, these nodules are often detected by chance during an imaging examination carried out for other purposes. Cancer was observed in 46% of these patients.
A retrospective study assessed data from 1328 patients who underwent thyroid surgery at 16 centers in 4 countries.
Of these patients, 34% had presented with thyroid-related symptoms and 41% were asymptomatic.
The remaining 25% of patients were operated on for endocrine problems, such as hyperthyroidism, or were under surveillance, and the initial mode of detection was unknown.
Overall, cancer was detected in 46% of patients, of which only 30% of patients were symptomatic. 51% of patients had no thyroid-related symptoms.
Most cancers in asymptomatic patients were smaller than those in patients in the symptomatic group (mean: 2.1 cm versus 3.2 cm).
Among asymptomatic patients, 61% of tumors were smaller than 2 cm, while 38% were larger than 2 cm.
The percentage of tumors larger than 4 cm was 9% in the asymptomatic group and 29% in the symptomatic group.
Further evaluation of the mode of nodule detection showed that, for asymptomatic nodules, 6% were detected following a diagnostic cascade, 20% were radiological or incidental findings, 1% were detected during a screening requested by patients and 13% were detected during a screening examination by clinicians.
A geographical assessment showed that South Africa and Denmark had the highest rates of nodules found in symptomatic patients, with rates of 79% and 54%, respectively, compared to only regarding 30% in the United States and 30% in Canada.
“The results of this study suggest that the detection of thyroid nodules in asymptomatic patients is still responsible for a significant number of thyroid surgeries, rather than an increase in the true incidence of thyroid cancer,” state the authors.
