NEW YORK (Reuters Health) – Small suspicious cervical lymph nodes detected after thyroidectomy for papillary thyroid cancer (PTC) usually remain stable for years, researchers advised in a recent paper.
“Detection of non-palpable lateral neck lymph node metastases by ultrasound in patients with well differentiated thyroid cancer does not mean that the thyroid cancer is going to get out of control, it does not mean that they have to rush to surgery to prevent the disease from either being locally invasive or develop distant metastases, and therefore, there is little reason to rush to surgery in this setting,” Dr. R. M. Tuttle from Memorial Sloan-Kettering Cancer Center, New York told Reuters Health in an email.
In a report online May 25 in The Journal of Clinical Endocrinology & Metabolism, Dr. Tuttle and colleagues describe the natural history of abnormal lymph nodes identified on routine surveillance neck ultrasound after thyroidectomy for PTC in 166 patients.
Most patients (70%) had lymph nodes with two or more abnormal features, and the median size of the lymph nodes was 1.3 cm (range, 0.5-2.7 cm) in largest diameter.
After a median 3.5-year follow-up, the suspicious nodes had grown by at least 3 mm in 33 patients (20%) and by at least 5 mm in 15 (9%). In 23 patients (14%), the suspicious nodes had resolved by the end of follow-up.
Thirteen of the 33 patients with lymph node growth underwent fine-needle aspiration biopsy that demonstrated PTC in eight cases, reactive changes in four cases, and nondiagnostic cytology in one case.
Ultimately, an ultrasonographically suspicious lymph node was cytologically proven to be PTC in 22 of 166 patients.
None of the clinical or sonographic features had a high enough positive predictive value to reliably determine which nodules were likely to grow, the authors say.
All 22 patients who underwent salvage neck dissection were confirmed to have metastatic PTC, and three of 18 patients with a measurable thyroglobulin level before removal of the suspicious lymph node achieved levels less than 0.6 ng/mL on suppression postoperatively.
“When one tries to balance the risk and benefits of immediate surgical resection of all suspicious lymph nodes identified by ultrasound, I am concerned that we may actually be hurting more patients than we are helping,” Dr. Tuttle said. “This is a hard concept for many patients and many clinicians…we have all been taught that cancer should be resected as soon as it is identified…this concept that some thyroid cancers grow so slowly and are often quite indolent…that well meaning treatments may be more harmful than the disease itself is difficult for clinicians (and patients) to understand and accept.”
He continued, “We are not recommending routine observation for poorly differentiated metastases, or markedly FDG PET positive metastases, or metastases that are demonstrated to be growing…each of these would be good reason to considering a neck dissection. However, in our series (that were 85% well differentiated papillary thyroid cancers), our data would suggest that many of these abnormal lymph nodes will remain stable for prolonged periods (some even resolve). Rather than rushing to do fine needle aspiration of all of these small lymph nodes with subsequent surgical resection, a more cautious observation approach can be safely considered.”
According to his group’s paper, these recommendations are consistent with the current American Thyroid Association guidelines that allow for observation of abnormal lymph nodes less than 5 to 8 mm in smallest diameter with biopsy deferred unless there is documented growth or if the node threatens vital structures.
J Clin Endocrinol Metab 2012.