P-177: PDCD6 Expression as a Prognostic Indicator in Multiple Myeloma

Introduction: Multiple myeloma (MM) is a clinically heterogeneous malignant hematological disorder with a variable prognosis. The programmed cell death protein 6 (PDCD6) has been linked to the progression of various cancers and is known to be associated with poor clinical outcomes. The objective of this study was to investigate the expression levels of PDCD6 in MM and to explore its correlation with prognostic parameters.

Methods: We conducted a comprehensive analysis of PDCD6 expression in a cohort consisting of 8 healthy controls, 11 patients with monoclonal gammopathy of undetermined significance (MGUS), 5 with smoldering multiple myeloma (SMM), 92 with newly diagnosed MM, and 5 with plasma cell leukemia (PCL). PDCD6 expression levels were quantified using quantitative PCR (qPCR). Kaplan-Meier survival analysis and Cox regression analysis were employed to assess the relationship between PDCD6 expression and progression-free survival (PFS) and overall survival (OS).

Results: PDCD6 expression levels were found to increase progressively with disease advancement when compared to healthy controls. Specifically, PDCD6 expression was higher in patients with MGUS, SMM, newly diagnosed MM, and PCL in ascending order. The optimal cutoff value for PDCD6 expression, as determined by X-tile analysis, was significantly associated with prognostic outcomes in newly diagnosed MM patients. Patients were categorized into high and low PDCD6 expression groups based on this threshold. The Kaplan-Meier survival analysis revealed that high PDCD6 expression was significantly associated with poor prognosis. The median overall survival (OS) for patients with high PDCD6 expression was 29 months, whereas the median OS for patients with low PDCD6 expression had not been reached (p< 0.001). Similarly, the median progression-free survival (PFS) for high PDCD6 expression patients was 19 months compared to 41 months for low PDCD6 expression patients (p< 0.001). Clinical correlation analysis indicated that high PDCD6 expression was significantly associated with older age, advanced ISS stage, and deletion of chromosome 17p in MM patients. The Cox regression analysis demonstrated that high PDCD6 expression, along with older age, advanced ISS stage, and chromosome 17p deletion, were independent adverse prognostic factors for both PFS and OS. Notably, PDCD6 overexpression was identified as an independent prognostic factor, suggesting its potential utility in prognostic stratification of MM patients.

Conclusions: Our study underscores the importance of PDCD6 in the prognosis of multiple myeloma and provides a foundation for further research into its clinical applications. The identification of PDCD6 as an independent prognostic factor offers valuable insights for the development of targeted therapies, ultimately aiming to enhance patient management and outcomes in multiple myelom