Abstract 3354: Hsp70 is an independent predictor of recurrence-free survival in differentiated thyroid cancer

Background: Differentiated Thyroid Cancer (DTC) has an indolent nature and generally has favorable prognosis. However, tumor recurrence is a major concern and can be noted several years after initial treatment. Identifying markers that can predict recurrence could lead to better management of DTC. Heat shock protein 70 (Hsp70), a molecular chaperone, has been shown to be associated with tumor recurrence and poor prognosis in other tumors. However, its role in predicting outcome in DTC is not well explored. Methods: A total of 1710 DTC cases were included in the study. Hsp70 expression was evaluated by immunohistochemistry using tissue microarray to analyze the clinico-pathological associations. Kaplan-Meier curve analysis was used to compare recurrence-free survival (RFS). Cox proportional hazards model was used for multivariable analysis. Results: Hsp70 over-expression was noted in 71.6% (1224/1710) of DTC cases and was significantly associated with adverse clinico-pathological characteristics such as extrathyroidal extension (p = 0.0039), T4 tumors (p = 0.0002), lymph node metastasis (p = 0.0118), distant metastasis (p = 0.0130), advanced tumor stage (p = 0.0312) and tumor recurrence (p < 0.0001). Interestingly, HSP70 over-expression was found to be associated with shorter RFS (p < 0.0001). On multivariable analysis, HSP70 was an independent predictor of RFS (Hazard ratio = 1.82; 95% confidence interval = 1.33 - 2.55; p = 0.0001). Conclusion: Our data suggests that Hsp70 is associated with poor prognosis in DTC and is a useful biomarker for predicting tumor recurrence. DTC patients whose tumor shows over-expression of Hsp70 should be subjected to more intense follow-up to identify potential tumor recurrence. Citation Format: Sandeep K. Parvathareddy, Zeeshan Qadri, Abdul K. Siraj, Padmanaban Annaiyappanaidu, Nabil Siraj, Khawla S. Al-Kuraya. Hsp70 is an independent predictor of recurrence-free survival in differentiated thyroid cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3354.