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Active surveillance in small cytological indeterminate thyroid nodules: a call to common sense?
Anabella Smulever1, Fabián Pitoia2
1Division of Endocrinology, Hospital de Clínicas, University of Buenos Aires, Buenos Aires, Argentina.
Insights
Active surveillance (AS) for Bethesda IV thyroid nodules, though not guideline-supported, shows excellent outcomes in selected patients. This approach is viable when molecular testing is limited and surgery is not preferred, especially for low-risk tumors.
Area of Science:
- Endocrinology
- Oncology
- Surgical Pathology
Background:
- Thyroid nodules classified as Bethesda category IV (B IV) are indeterminate, typically managed with molecular testing or surgery.
- Current guidelines do not recommend active surveillance (AS) for these nodules.
- Access to molecular testing and patient preference for surgery can be limiting factors in management.
Purpose of the Study:
- To describe the clinical characteristics and outcomes of patients with Bethesda IV thyroid nodules managed with active surveillance.
- To evaluate the safety and efficacy of AS in a selected cohort of patients with indeterminate thyroid nodules.
Main Methods:
- A prospective study of 155 patients with B IV thyroid nodules.
- Active surveillance was implemented for patients unable or unwilling to undergo immediate molecular testing or surgery, or with high surgical risk.
- Follow-up included monitoring for tumor enlargement and metastasis development.
Main Results:
- Active surveillance was initiated in 15% (n=23) of patients.
- After a median follow-up of 42 months, 14% experienced tumor enlargement without metastasis.
- Four patients (17%) underwent deferred surgery, with diagnoses including follicular adenoma and a follicular variant of papillary thyroid carcinoma, all without evidence of disease post-surgery.
Conclusions:
- Active surveillance may be a safe and effective alternative for selected patients with Bethesda IV thyroid nodules, particularly when molecular testing is inaccessible or surgery is not preferred.
- The study highlights excellent outcomes in patients managed with AS, challenging current management paradigms for indeterminate thyroid nodules.
- Further research is warranted to define optimal selection criteria for AS in B IV thyroid nodules.
Purpose:
To describe the clinical characteristics and outcomes of patients with cytologically Bethesda IV category (B IV) thyroid nodules who opted for active surveillance.
Materials And Methods:
We prospectively evaluated 155 patients with a single thyroid nodule classified as B IV. Immediate molecular testing and/or thyroid surgery was offered, except when the patient (i) could not afford molecular testing/rejected the surgery, (ii) had a high surgical risk, (iii) had other disorders/comorbidities which needed to be addressed with higher priority, and (iv) had undetectable serum calcitonin levels, in whom active surveillance (AS) was performed.
Results:
From 155 patients, only two patients could afford molecular testing; 84% (n = 130) underwent immediate thyroid surgery: lobectomy was performed in only 8% (n = 10). AS was the initial management for 15% (n = 23) of the patients. The frequency of tumor enlargement was 14% (n = 3), after a median of 42 months (range, 7-72) of follow-up, without any evidence of lymph node or clinical distant metastases development. Deferred surgery was performed in 4 patients (17%) after a median of 24 months (range, 12-48) of AS. Follicular adenoma was diagnosed in three and a follicular variant of papillary thyroid carcinoma in one patient, all of them without evidence of disease after 12 months of follow-up.
Conclusions:
Despite current guidelines does not support AS for indeterminate Bethesda IV nodules, our findings showed that most of these patients had excellent outcomes, in a setting where lobectomy was not the preference and the access to molecular testing was limited. Probably AS could be a valid alternative in these low-risk tumors in selected patients.
