The role of prophylactic central compartment lymph node dissection in differentiated thyroid carcinoma

Background: Differentiated thyroid carcinoma, arising from thyroid follicular epithelial cells, accounts for the vast majority of thyroid carcinomas. Of the differentiated cancers, papillary cancer comprises about 85% of cases compared to about 12% that have follicular histology, including conventional and oncocytic (Hurthle cell) carcinomas, and <3% that are poorly differentiated tumors. In general, stage for stage, the prognoses of PTC and follicular cancer are similar. The aim of this study is to evaluate the benefit of central compartment lymph node dissection in accurate staging of the disease and plan radioiodine treatment and dosing. And also to assess the morbidity associated with central neck dissection. Materials and methods: This was a prospective clinical study conducted at MNJIO and RCC, Hyderabad. 20 patients with carcinoma thyroid who underwent total thyroidectomy and prophylactic central compartment lymph node dissection from December 2015 to December 2017 were included. The protocol was submitted to the ethics committee at Osmania Medical College and was approved. Results: We analyzed the number of patients of that age in whom the disease stage changed due to the presence of central nodal dissection. Prophylactic CND resulted in upstaging of tumour in 2/20 (10%) patients from stage I to stage II. Also in 4/20 (20%) patients, the evidence of node metastases influenced also the therapeutic strategy because these patients would not have been treated with 131-I if the prophylactic central neck dissection had not been performed. Thus a prophylactic CLND may play an even larger role in determining RAI use. A prophylactic CLND that demonstrates a lack of lymph node metastasis would strengthen the case not to use RAI treatment in a low-risk patient. Conclusion: With the available evidence, we advocate a selective approach to performing prophylactic CND and to be done in high volume centres. Routine prophylactic central lymph node dissection should be avoided in the absence of involved lymph nodes, reserving the procedure to “high-risk” patients as defined by ATA and European Society of Endocrine Surgeons, which include extremes of ages, large primary tumor size, and male gender, which were similar to high risk cases seen in our study.