Galectin-9 (Gal-9) expression can be negatively or positively associated with cancer patient prognosis, depending on the cancer type. However, the nature of this relationship remains unclear in multiple myeloma. Therefore, we evaluated the prognostic value of Gal-9 and its relationship with the expression of PD-L1 molecule, the most widely studied immune checkpoint inhibitor, in patients with newly diagnosed multiple myeloma. Gal-9 and PD-L1 levels in bone marrow aspirate samples were evaluated using immunofluorescence assays. Gal-9 positivity was defined as having ≥1% Gal-9-expressing plasma cells. PD-L1 expression was categorized as low or high based on its median value. The median OS of patients with positive and negative Gal-9 expression was 42 months and not reached, respectively. However, no significant difference was observed in OS between the two groups (P = 0.10). Patients with high PD-L1 expression had OS times of 14 and 43 months in the positive and negative Gal-9 expression groups, respectively. In the high PD-L1 expression group, patients expressing Gal-9 had significantly worse OS than those negative for it (P = 0.019). Multivariable Cox analysis confirmed that Gal-9 expression could independently predict shortened OS (hazard ratio, 1.090; 95% confidence interval, 1.015–1.171; P = 0.018) in patients with high PD-L1 expression. However, in the low PD-L1 expression group, patients with high Gal-9 expression exhibited a trend toward better OS (P = 0.816). Our results indicate that the prognostic value of Gal-9 may be related to PD-L1 expression in patients with newly diagnosed multiple myeloma.
Bibliographical noteFunding Information:
The authors thank the members of the Korea University Anam Hospital Clinical Trial Center, particularly Jin Wha Lee for her help collecting the clinical data, and Chan Min Lee for preparing the bone marrow samples. The authors also thank Seung-Yeon Oh for her technical support with the immunofluorescence analysis.
This research was supported by the Bio and Medical Technology Development Program of the National Research Foundation, funded by the Ministry of Science and ICT (NRF-2017M3A9C8060403) and a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI17C2072). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
© Copyright © 2021 Lee, Park, Kim, Kang, Lee, Kim and Kim.
- galectin-9 (Gal-9)
- multiple myeloma
- plasma cells
- programmed death-ligand 1 (PD-L1)
ASJC Scopus subject areas
- Cancer Research