SAN DIEGO-Several scientific sessions at the 2007 Combined Otolaryngology Spring Meeting focused on the topic of papillary thyroid cancer (PTC), which accounts for about 75% of thyroid cancers in the United States.1 As members of the American Head and Neck Society (AHNS), Tarik Y. Farrag, MD, and Mark G. Shrime, MD, presented the results of their studies, Identifying Patients Undergoing Thyroidectomy for Papillary Thyroid Cancer at Risk for Harboring Multiple Central Neck Lymph Node Metastases and Cost-Effective Management of Low-Risk Papillary Thyroid Carcinoma, respectively.
Explore this issue:July 2007
Timing of Central Neck Dissection
Dr. Farrag, a postdoctoral fellow in the Department of Otolaryngology-Head & Neck Surgery at Johns Hopkins School of Medicine, performed a retrospective chart review of 51 consecutive patients with PTC who underwent primary thyroidectomy and concurrent removal of central neck lymph nodes (LN) between March 2000 and November 2006 at Johns Hopkins to identify the patient population with PTC undergoing primary thyroidectomy at risk for harboring multiple central neck LN metastases.
This is the first time the concept has been addressed by this approach, said Dr. Farrag. Due to the potential complications associated with central LN dissection, there is controversy in the current literature on when to do it, and what the factors are that could reliably predict a positive disease in this compartment in this subset of patients, which then could justify an extensive central compartment dissection at the time of primary thyroidectomy.
Study participants were divided into two categories: (1) 15 patients whose operative notes indicated direct removal of suspicious LN(s) only (1-6 LNs removed; median = 2), and (2) 36 patients whose operative notes showed that an attempt was made to clear more than just suspicious LNs (4-27 LNs; median = 13). The second category was further divided into two groups based on whether the patient was (A) negative or (B) had positive multiple LNs on final pathology.
Comparisons between A and B were performed utilizing four factors, which had the following results:
- Primary tumor size ≥ 3cm: positive predictive value (PPV) = 82%; sensitivity (S) = 45%.
- Lateral neck LN metastasis detected by preoperative imaging (ultrasound and/or CT) and confirmed by fine needle aspiration and/or intraoperative frozen section: PPV = 89%; S = 63%.
- Preoperative suspicion of central LN metastasis based on physical exam and imaging: PPV = 100%; S = 26%.
- Intraoperative suspicion or histopathologic confirmation of central neck LN metastasis: PPV = 93%; S = 91%; p = 0.008.
Our study demonstrated that intraoperative central LN evaluation is an important step during thyroidectomy for PTC to predict those who are likely to harbor multiple LN metastases, said Dr. Farrag. The other three factors were found to be highly predictive for patients harboring multiple central nodal metastases; however, they had variable sensitivity.