BACKGROUND
Most patients diagnosed with thyroid cancer have an excellent prognosis. This is because there are excellent treatments available, with the first treatment almost always being surgery. An important guiding part of the management of thyroid cancer is an ongoing assessment of risk of the cancer persisting or returning after the initial therapy. This has resulted in incorporating higher thresholds for surgery and therapy with radioactive iodine and personalizing treatment options by factoring in patients’ preferences. Since many of the thyroid cancers discovered are low risk, this means removal of the lobe containing the cancer rather than removing the entire thyroid gland.

When a lobe is removed, there is usually also removal of lymph nodes in the central neck behind the lobe. Traditionally, the presence of cancer in lymph nodes removed during surgery has been associated with higher cancer recurrence rates. When cancer is found in the lymph nodes, this may lead to additional surgery to remove the remaining lobe (completion thyroidectomy) and to consider radioactive iodine therapy.

The goal of this study was to examine the clinical course of patients with cancer found in the lymph nodes after a lobectomy for thyroid cancer.

THE FULL ARTICLE TITLE
Alameer E et al. Partial thyroidectomy with incidental metastatic lymph nodes. JAMA Otolaryngol Head Neck Surg 2024;150(1):49-56. doi: 10.1001/ jamaoto.2023.3668. PMID: 37971746.

SUMMARY OF THE STUDY
This was a study performed at Memorial Sloan Kettering Cancer Center (MSKCC) reviewing patients undergoing surgery for thyroid cancer between 1985 and 2015. The authors included patients who had undergone thyroid lobectomy or isthmusectomy without lateral neck dissection and had cancer in lymph nodes identified on final pathology. The study group consisted of patients who did not proceed with immediate completion surgery and were followed clinically.

They also identified a subgroup of patients who met the same inclusion criteria but who had undergone immediate completion thyroidectomy. Data on patients’ demographics, surgical procedure, histopathology, cancer staging, and time to completion thyroidectomy were collected. Clinical outcomes, including recurrence of cancer and diseasespecific and overall survival, were reviewed.

The authors identified 1306 patients who had undergone thyroid lobectomy or isthmusectomy at Memorial Sloan Kettering Cancer Center between 1986 and 2015. Of these patients, 85 had cancer found in central lymph nodes; 74 of these were observed without immediate completion thyroidectomy. The remaining 11 patients opted for completion thyroidectomy. Average age at surgery was 39 years and 59% of patients were female. Lobectomy was performed in 64 patients and included isthmusectomy in 10. Classic papillary thyroid carcinoma (PTC) was the most common cancer type (46% of cases), followed by tall-cell PTC in 18%, follicular variants of PTC in 6.8%, solid/trabecular variants of PTC in 1.4%, and oncocytic carcinoma in 1.4%. Based on the American Thyroid Association (ATA) risk stratification, 70% of patients were characterized as intermediate risk for recurrence. The average diameter of metastatic lymph nodes was 3 mm (range, 0.7–12). Most patients had 1 positive node and 6 patients had 3-5 involved lymph nodes.

The 11 patients who proceeded directly to completion thyroidectomy were more likely to have additional aggressive cancer features in addition to cancer in the lymph nodes. The average follow-up for patients who were observed was ~48 months. The pathology of completion thyroidectomy showed benign nodules in two cases and a 2-mm microscopic PTC in the third. No radioactive iodine treatment was administered. Five-year disease specific survival was 100%, overall survival 96.2% and recurrence free survival 97.4%.

WHAT ARE THE IMPLICATIONS OF THIS STUDY?
In this study, patients undergoing lobectomy or isthmusectomy for thyroid cacner and found to have cancer in the central lymph nodes and not proceeding to routine completion surgery had excellent outcomes. This is an important study that will help continue to limit surgery to those that would most benefit from it and to spare extensive surgery in patients at low risk of cancer recurrence.

— Alan P. Farwell, MD

Table of Contents | PDF File for Saving and Printing