Predictive Factors for RAI-Refractory Disease and Short Overall Survival in PDTC.

Abstract

BACKGROUND:

The clinical phenotype of poorly differentiated thyroid cancer (PDTC) can vary substantially. We aim to evaluate risk factors for radioiodine refractory (RAI-R) disease and reduced overall survival (OS).

METHODS:

We retrospectively screened our institutional database for PDTC patients. For the assessment of RAI-R disease, we included patients who underwent dual imaging with 18F-FDG-PET and 124I-PET/131I scintigraphy that met the internal standard of care. We tested primary size, extrathyroidal extension (ETE), and age >55 years as risk factors for RAI-R disease at initial diagnosis and during the disease course using uni- and multivariate analyses. We tested metabolic tumor volume (MTV), total lesion glycolysis (TLG) on 18F-FDG-PET, and the progression of stimulated thyroglobulin within 4-6 months of initial radioiodine therapy as prognostic markers for OS.

RESULTS:

Size of primary >40 mm and ETE were significant predictors of RAI-R disease in the course of disease in univariate (81% vs. 27%, p = 0.001; 89% vs. 33%, p < 0.001) and multivariate analyses. Primary tumor size was an excellent predictor of RAI-R disease (AUC = 0.90). TLG/MTV > upper quartile and early thyroglobulin progression were significantly associated with shorter median OS (29.0 months vs. 56.9 months, p < 0.05; 57.8 months vs. not reached p < 0.005, respectively).

DISCUSSION:

PDTC patients, especially those with additional risk factors, should be assessed for RAI-R disease at initial diagnosis and in the course of disease, allowing for early implementation of multimodal treatment. Primary tumor size >40 mm, ETE, and age >55 are significant risk factors for RAI-R disease. High MTV/TLG is a significant risk factor for premature death and can help identify patients requiring intervention.

• Authors: David Kersting, Robert Seifert, Lukas Kessler, Ken Herrmann, Sarah Theurer, Tim Brandenburg, Henning Dralle, Frank Weber, Lale Umutlu, Dagmar Führer-Sakel, Rainer Görges, Christoph Rischpler, Manuel Weber
• Journal: Cancers (Cancers (Basel)) Vol. 13 Issue 7 (Apr 06 2021) ISSN: 2072-6694 [Print] Switzerland
• PMID: 33917322 (Publication Type: Journal Article)