Researchers revealed that higher levels of preoperative serum calcitonin (CT) accurately predicted lymph node involvement in patients with medullary thyroid carcinoma (MTC), as published in World Journal of Surgery. The authors proposed different thresholds based on the hereditary nature of the tumor.

Juez and colleagues demonstrated that patients with MTC with preoperative CT values of 240 to 627 pg/mL for sporadic tumors and 142 to 200 pg/dL for hereditary tumors were 87% more likely to have positive contralateral ganglions. 

This multicenter, observational study retrospectively collected CT values prior to surgical treatment in 244 patients who underwent total thyroidectomy (TT) with central compartment lymph node dissection (CCLND) and, in some cases, also a lateral lymph node dissection (LLND). This correlates with current guidelines, in which TT and CCLND are recommended in most cases of MTC.


Continue Reading

The criteria for executing LLND are not yet standardized, however. Some authors advocate prophylactic lymphadenectomy, while others suggest only excising ganglions detected as positive on ultrasound due to possible surgical complications.

“We therefore propose TT + CCLND if the basalCT values are <140 pg/mL, TT + CCLND + LLND if the basalCT values are 140–199 pg/mL, and TT + CCLND + bilateral LLND if the basalCT values are >200 pg/mL,” the authors wrote.

Read more about MTC prognosis

Although serum CT is currently used as a specific marker for MTC and has been previously linked to lymph node involvement, these cut-off points provide new objective usefulness. Similarly, other techniques such as preoperative ultrasonography have been proven to help determine positive ganglion territories, but no specific guidelines are currently available. 

In neoplasms with greater rates of recurrence and mortality but limited therapeutic options, prediction markers that could modify the surgical conduct are valuable.

“With these cut-offs, the minimum surgical act in MTC should, in our opinion, be TT with CCLND due to the high rate of central lymph node involvement and the goal of decreasing as much as possible the need for reoperations in an already operated-on compartment, regardless of the tumor’s mutational state,” the authors concluded. 

Reference 

Juez LD, Mercader E, Amunategui I, et al. Extension of prophylactic surgery in medullary thyroid carcinoma. Differences between sporadic and hereditary tumours according to calcitonin levels and lymph node involvement. World J Surg. Published online January 28, 2022. doi:10.1007/s00268-022-06448-6