MRD and Biomarkers

Category: MRD and Biomarkers

Lymphocyte to monocyte ratio at minimal residual disease assessment predicted survival time among myeloma patients in complete response

(PA-191) Lymphocyte to Monocyte Ratio at Minimal Residual Disease Assessment Predicted Survival Time Among Myeloma Patients in Complete Response

Friday, September 19, 2025

Has Audio

Kazuhito Suzuki, MD, PhD

Associate Professor
Division of Clinical Oncology/Hematology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan

Introduction: Minimal residual disease (MRD) has already established as a surrogate marker for survival in myeloma patients who achieved complete response (CR), whereas the clinical significance of lymphocyte to monocyte ratio (LMR), serve as a prognostic factor associated with the immunological, has not investigated as prognostic markers. In this study, we evaluated the clinical impact of MRD negativity (MRD-ve) and LMR at MRD assessment.

Methods:   MRD was analyzed by multicolor flow cytometry (threshold, 1 × 10^-5). Sustained MRD-ve (sus-MRD-ve) was defined as continuing MRD-ve for 1year or longer. LMR was calculated at the time point when MRD was assessed. The cutoff of LMR was 3.75, which was a median value.

Results:   A total of 155 patients who achieved CR were included in this study, with a median age of 70 years. The number of patients treated with autologous stem cell transplantation (ASCT), daratumumab treatment, and other treatments were 72, 58, and 25, respectively. 108 patients (69.7%) achieved MRD negative. In a median follow-up time of 36.1 months, 3-year time to next treatment (TTNT) and overall survival (OS) rates from the first MRD assessment were 73.0% and 92.9%, respectively. The 3-year TTNT in the patients with sus-MRD-ve was significantly higher than in those without sus-MRD-ve (79.0% vs 73.0%, P=0.017) while there was no significant difference of 3-year TTNT between the patients with and without MRD-ve (74.0% vs 69.4%, P=0.478). LMR >3.75 was observed in the patients whose MRD assessment was done after ASCT compared to those after non-ASCT (59.5% vs 32.9%, P= 0.012). Additionally, LMR >3.75 tended to be related with not MRD-ve but sus-MRD-ve (P=0.221 and 0.064). The 3-year TTNT in the LMR >3.75 was significantly higher than those in the LMR< 3.75 (87.2% vs 56.8%, P< 0.001). LMR >3.75 was a significant prognostic factor for TTNT (HR 0.448, P=0.014) while sus-MRD-ve, which predicted TTNT significantly using univariate analysis, was not identified as a significant predictor (HR 0.549, P=0.115) using multivariate analysis. The 3-year OS in the LMR >3.75 was significantly higher than those in the LMR< 3.75 (98.3% vs 87.1%, P=0.012), whereas there was no significant difference of OS between the patients with and without sus-MRD-ve (3-year OS 96.5% vs 97.0%, P=0.853). LMR >3.75 was a significant prognostic factor for OS (HR 0.288, P=0.033) while MRD assessment after ASCT, which predicted OS significantly using univariate analysis, was not identified as a significant predictor (HR 0.366, P=0.096) using multivariate analysis.

Conclusions:

LMR >3.75 at MRD assessment tended to be associated with sus-MRD-ve and could be identified as a predictor of long TTNT and OS, suggesting that immunological status might improve survival time by contribution to continuous deep response. Therefore, we should pay attention not only treatment response but also immunological status in myeloma patients in CR to predict survival time.