Evaluation of CD56 and CD117 Double-positive as a Predictor of Poor Prognosis in Multiple Myeloma Patients: A Retrospective Analysis

Objective: Despite advancements in treatment, multiple myeloma (MM) remains a challenging hematologic malignancy. It is crucial to stratify risk and perform prognostic assessment through various markers, including the cluster of differentiation 56 (CD56) and thecluster of differentiation 117 (CD117) expression. However, the relationship of these markers with MM-related survival remains unclear. In this context, the objective of this study isto investigate the prognostic implications of CD56 and CD117 expression and associated clinical features in MM patients.
Materials and Methods: The population of this retrospective single-center study consisted of adult MM patients whose CD56 and CD117 expressionswere analyzed. Patients were divided into four groups according to their immunophenotypes: CD56+ CD117-, CD56-CD117+, CD56+CD117+, and CD56-CD117-.These groups were compared in terms of demographic and clinical characteristics, response to treatment, and survival outcomes.
Results: Of the 168 MM patients included in the study, CD56 positive, CD117 positive,CD56, and CD117 double-positive and double negative were observed in 57.1%, 38.1%, 21.4%, and 26.2%, respectively. Patients with double positivehad significantly higher cytogenetic risk and significantly lower overall response rate (ORR) compared toother patients(p<0.001 for both cases). ORR and overall survival (OS) were significantly lower in CD56 positivepatients than those CD56 negative (p=0.017 and p=0.004, respectively). Mortality rates were significantly higher in CD56 positive patients and CD117 positive than in those with double negative(p<0.001 and p=0.002). Double negative patients had significantly lower ORR and OS and higher mortality than others (p=0.001, p=0.002, and p<0.001, respectively). The high cytogenetic risk was found to bean independent predictor of shorter OS (p>0.001).
Conclusion: The study’s findings revealed that CD56 and CD117 double- positive MM patients had poorer prognosis, lower ORR, shorter OS, and higher mortality.