A-257 OMISSION OF LYMPH NODE DISSECTION IN MEDULLARY THYROID CANCER WITHOUT A DESMOPLASTIC STROMAL REACTION, COULD BE AN OPTION?

Abstract

Abstract Background Predictive criteria to determine the absence of node metastases from thyroid specimens are scarce for sporadic medullary thyroid cancer (MTC). It has been suggested that lymph node dissection could be avoided in patients with MTC without a desmoplastic stromal reaction (DSR-negative). The aim of our study was to perform analyse the correlation between DSR status and lymph node involvement in order to establish a criterion on which to base prophylactic surgery in these patients. Methods This was a multicentric retrospective cohort study of a prospectively maintained database of patients with medullary thyroid cancer treated in two tertiary hospitals using a standardised protocol and subdivided into DSR-negative and -positive groups. Intraoperative, long-term clinical and biochemical follow-up data were collected, and baseline parameters and histopathological characteristics were compared between groups. Results The study included 29 patients. In the DSR-negative group (24.1% of all tumours) no patient had central or lateral lymph node or distant metastases at diagnosis or during follow-up, and all patients were biochemically cured. In the DSR-positive group (75.9% all tumours), lymph nodes were present in 66% of patients. DSR-negative tumours were more often stage pT1a and levels of basal calcitonin were significantly lower. Conclusion Lymph node surgery may be individualised in medullary thyroid cancer based on intraoperative analysis of the DSR. Patients with DSR-negative tumours may not require lymph node dissection.