Abstract 6277: Tall cell variant papillary thyroid carcinoma from Middle Eastern patients have worse outcome than classical papillary thyroid carcinoma using propensity score matching

Abstract

Abstract The tall cell variant of Papillary Thyroid Carcinoma (TCV-PTC) is the most common aggressive variant of PTC. The impact of TCV-PTC on patients’ prognosis still remains controversial. Moreover, the clinico-pathological and prognostic effect of TCV-PTC from Middle Eastern ethnicity remains unexplored. We aimed to study TCV-PTC in comparison to classical PTC in Middle Eastern patients and their impact on prognosis. We performed a retrospective cohort study of tall cell variant (TCV-PTC) and classic variant of papillary thyroid carcinoma (CV-PTC) after post-surgical radioactive iodine therapy. We used the propensity score matching (1:3 matching ratio) to account for differences between recipients of TCV-PTC vs CV-PTC. Univariate and multivariate analysis were performed to assess the independent factors for persistent/recurrent disease. Kaplan-Meier curve analyses were used to compare disease-free survival (DFS). In total, 174 (16.3%) patients with TCV-PTC and 891 (83.7%) patients with CV-PTC were included. After propensity score matching, 174 pairs of patients were selected (TCV-PTC, n = 174; CV-PTC, n = 522). In the matched analysis, higher proportions of TCV-PTC experienced persistent/recurrent disease compared with CV-PTC (25.7% vs 31.4%; p = 0.0119). In multivariate analyses of clinical and tumor characteristics, histological type of TCV-PTC (odds ratio, 2.09; 95% confidence interval, 1.28-3.40; p = 0.0031) was associated with increased risk of persistent/recurrent disease. The five-year DFS rates for the TCV-PTC and CV-PTC groups were 48.5% and 73.1%, respectively. The Kaplan- Meier analysis indicated that the TCV-PTC group (p < 0.0001) had shorter DFS. In conclusion, when other clinico-pathological factors were similar, this propensity score matched analysis showed that histological subtype TCV-PTC is by itself an independent predictive marker of persistent/recurrent disease in Middle Eastern patients. Therefore, individualized therapeutic approaches might be needed for this aggressive PTC subtype. Citation Format: Khawla S. Al-Kuraya, Sandeep K. Parvathareddy, Abdul K. Siraj, Saeeda O. Ahmed, Nabil Siraj, Manal Manakhan, Hassan Aldossari. Tall cell variant papillary thyroid carcinoma from Middle Eastern patients have worse outcome than classical papillary thyroid carcinoma using propensity score matching [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6277.