Dynamics of the prognostic index during the course of treatment for anaplastic thyroid carcinoma.

Purpose: Tumor/node/metastasis staging and prognostic index (PI) are used to predict prognosis and guide treatment for anaplastic thyroid carcinoma (ATC). With the advent of treatments, such as BRAF/MEK inhibitors and immune checkpoint inhibitors, dynamic markers to assess disease status and treatment efficacy are needed. This study examined the utility of PI as a dynamic marker for ATC treatment.

Methods: This retrospective study investigated 20 patients with ATC who were treated aggressively from January 2011 to December 2022. Patients were categorized into low-, high-, low-, and high-high groups according to the PI before and after treatment. Survival was then compared between the groups.

Results: The median overall survival was not reached for the Low-Low, 363 days for the High-Low, 158.5 days for the Low-High, and 90.5 days for the High-High groups (p < 0.01). Among the 13 patients with an initially high PI, 6 patients achieved a low PI during treatment, but three showed subsequent increases. Categorizing PI further into decreased, temporarily decreased, and non-decreased groups, median overall survival was 363 days, 158.5 days, and 87 days, respectively (p < 0.01).

Conclusion: PI is a critical prognostic indicator that facilitates treatment decision-making for ATC. PI may also have potential as a dynamic marker for assessing the disease status and treatment efficacy.