Pretreatment hemoglobin, myeloma subtype, and induction regimens as independent prognostic factors for survival after autologous stem cell transplantation in multiple myeloma: A retrospective cohort study.

Abstract

Background: Autologous hematopoietic stem cell transplantation (auto-HSCT) is a standard of care for eligible patients with multiple myeloma (MM). However, outcomes vary significantly. While cytogenetics and the International Staging System (ISS) are established prognostic markers, the independent predictive roles of pretreatment hemoglobin (Hb) levels, myeloma subtype, and specific induction regimens remain less defined. This study aimed to evaluate these factors to refine risk stratification and improve prognostication.

Methods: We retrospectively analyzed 350 MM patients who underwent a first auto-HSCT between 2001 and 2019 at Beijing Chao-Yang Hospital. We evaluated the prognostic impact of baseline variables, including Hb level (<10 g/dL vs. ≥10 g/dL), myeloma subtype (IgG vs. non-IgG), bone marrow plasma cell infiltration, and induction regimen type (bortezomib-based vs. others), on progression-free survival (PFS) and overall survival (OS). Survival analyses were performed using Kaplan-Meier methods and Cox proportional hazards regression models.

Results: The median follow-up was 58 months. Median PFS and OS for the entire cohort were 42 months (95 % CI 36-48) and 98 months (95 % CI 83-113), respectively. Baseline Hb levels were inversely correlated with both bone marrow plasma cell infiltration (r = -0.45, P < 0.001) and serum creatinine (r = -0.38, P < 0.001). In multivariate Cox regression analysis, three factors independently predicted superior PFS: pretreatment Hb ≥10 g/dL (HR = 0.65, 95 % CI 0.47-0.91, P = 0.012), IgG myeloma subtype (HR = 0.72, 95 % CI 0.54-0.95, P = 0.018), and receipt of a bortezomib-based induction regimen (HR = 0.58, 95 % CI 0.40-0.84, P = 0.004). Patients who achieved a deep response (complete response [CR] or very good partial response [VGPR]) post-transplant had significantly longer PFS (median 55 months) compared to those with a partial response or less (median 37 months, P = 0.044).

Conclusion: This study identifies pretreatment hemoglobin, IgG subtype, and bortezomib-based induction as significant and independent predictors of survival outcomes following auto-HSCT in MM patients. Our findings highlight the prognostic utility of baseline hemoglobin, a simple and universally available marker that reflects both tumor burden and renal function, which complements established risk factors like ISS stage and cytogenetics. These results support the integration of these factors into prognostic models to better tailor therapeutic strategies and manage patient expectations.