Endocrine Abstracts

Background: Anaplastic thyroid carcinoma (ATC) is associated with the highest mortality risk of any thyroid-arising tumor; however, there is currently no effective therapy for ATC, and multimodal therapy is associated with a relatively high mortality risk. Here, we investigated the effects of neoadjuvant chemoradiotherapy on patients with ATC treated with paclitaxel and intensity-modulated radiation therapy (IMRT).

Methods: The medical records of 157 patients with ATC at Gangnam Severance Hospital were reviewed between January 2016 and November 2022. Only nine patients were eligible for surgery after neoadjuvant chemoradiotherapy according to the Gangnam Severance Hospital protocol for ATC.

Results: Seven patients were female, and two were male. The median age of the patients was 62 years (range: 53–76 years). The median tumor size of the patients was 3.94 cm (range: 2.1–5.6 cm). All the patients were treated with neoadjuvant paclitaxel and concomitant IMRT. The median number of cycles of neoadjuvant paclitaxel was 5 (range: 2–6 cycles) and the median IMRT dose was 5680 cGy (range: 5250–6600 cGy). Six patients showed a reduction in tumor size after neoadjuvant chemoradiotherapy. Three patients showed no significant differences or increases in tumor size after neoadjuvant chemoradiotherapy, but did display eminent tumor necrosis. Of the six patients with initial regional node metastasis, four showed a decrease in the size of metastatic nodes and internal necrosis. One patient had initial distant metastasis in the lung, and another showed newly diagnosed lung metastasis after neoadjuvant therapy. The mean interval from neoadjuvant radiation therapy to surgery was 93 days (range: 14–170 days). The median survival of patients with ATC who received neoadjuvant chemoradiotherapy was 358 days (range: 123–2,023 days).

Conclusion: Effective neoadjuvant chemoradiotherapy followed by complete surgical resection could result in good prognosis in terms of median survival, with safe local progression control.