Resident physician Translational Hematology and Oncology, Tuassig Cancer Institute, Cleveland Clinic, United States
Introduction: Autologous hematopoietic cell transplant (AHCT) remains the standard consolidation in multiple myeloma (MM) patients who achieve at least partial response to induction chemotherapy. Indeed, AHCT aims to deepen response in MM patients while also prolonging remission in a disease of known eventual relapse. Here, we explored our internal cohort of MM patients undergoing AHCT to test whether a BMPC cut off of 5% provides survival advantages in patient who responded to a single line of modern induction therapy.
Methods: We screened all MM patients who underwent AHCT between 2011 and 2021. Inclusion criteria included transplant within 12 months of diagnosis, receiving a single line of modern induction chemotherapy, and absence of relapse prior to AHCT. Patients were subsequently stratified into BMPC < 5% and ≥5% pre-AHCT. Kaplan-Meier analysis determined median overall survival (mOS) and median progression free survival (mPFS) post-AHCT with subgroup analysis according to the cytogenetic risk categories as well.
Results: A total of 311 patients with available data were included in our study. On further BMPC stratification, we identified 233 (74.9%) patients with BMPC < 5% and 78 (25.1%) patients with BMPC ≥5% at AHCT, respectively. Both groups had similar baseline characteristics, including age at diagnosis (median 61.5 vs 60.4 years; P=0.86), age at transplant (62.0 vs 61.0 years; P=0.87), smoking history (65.9 vs 64.8%, 30.2 vs 33.8%, 3.9 vs 1.4% for never, prior, and current smokers; P=0.54), sex (Males 59.2 vs 61.1%; P=0.78), ethnicity (White 84.5 vs 91.7%; P=0.31); Eastern Cooperative Oncology Group (ECOG) performance status (P=0.81), International Scoring System stages (33.7 vs 38.7%, 42.7 vs 32.3%, 23.6 vs 29%, for stage I, II, and III; P=0.34), cytogenetic risk (High-risk 41.4 vs 37.7%; P=0.61), Immunoglobulin subtype (IgG 69.2 vs 66.1%; P=0.65), Melphalan dose (high dose 200 mg/m2 97.0 vs 98.6%; P=0.45), and Mobilization regimen (G-CSF + Plerixafor 87.1 vs 88.7%; P=0.71) for BMPC < 5% and BMPC ≥5% at AHCT, respectively. Patients with < 5% BMPC had better probability of OS (median 88.8 vs 68.1 months; HR 0.6 95% CI 0.3-1.2; P=0.07), but it did not reach statistical signficance. There was no difference in PFS (median 35.5 vs 33.1 months; HR 0.8 95% CI 0.5-1.2; P=0.2), for the BMPC < 5% and BMPC ≥5% groups. On subgroups analysis, no differences were noted in OS (median 70.1 vs 68.1 months; HR 0.4 95% CI 0.1-1.3; P=0.13) and PFS (median 22.6 vs 22.4 months; HR 0.9 95% CI 0.5-1.7; P=0.72) for patients who are of high risk cytogenetics. In contrast, patients who are of standard risk cytogenetics had statistically significant lower OS (median 86.6 vs 95.4 months; HR 0.3 95% 0.1-0.9; P=0.04) but not in mPFS (median 77.4 vs 34.4 months; OR 0.5 95% CI 0.2-1.1; P=0.06) if they belonged to the BMPC ≥5% group.
Conclusions: A BMPC cut off of 5% at AHCT may be a useful prognostic marker for survival outcomes in MM patients of standard risk cytogenetics being evaluated for AHCT.
