Adapted physical activity during first line therapy in multiple myéloma : Innovative assessment of physical status during first-line therapy in 22 multiple myeloma patients

Abstract Background Multiple myeloma (MM) patients have been first excluded from exercise programs due to their pain and fracture risk. However, recent therapeutic advances have improved their prognosis and symptom control, making exercise feasible and well-tolerated. Before implementing exercise program in MM patients, the characterization of treatment-induced side effects on exercise capacity is needed to determine and design further tailored exercise programs. Methods We conducted a prospective study in 22 patients (mean age: 55 years old) newly diagnosed with MM and treated with daratumumab-bortezomib-lenalidomide-dexamethasone (D-VRd), followed by autologous stem cell transplantation (ASCT) and consolidation. After initial management of myeloma-related bone pain and fracture risk, patients completed four standardized assessments: (1) at diagnosis, (2) after 8 weeks of induction, (3) prior to ASCT, and (4) before maintenance therapy. Muscle mass, muscle force and muscle fatigue, and exercise capacity were measured and combined with questionnaires of quality of life and physical activity level . Results All assessments were feasible and well tolerated. While an increase in exercice capacity (P=0.003) was documented, we also found a decrease in muscle mass. More precisely, trunk (P=0.048), legs (P=0.001) and arms (P=0.012) muscle mass was reduced. No changes were observed for muscle force and fatigue. Finally, pain (P=0.040) decreased during treatment leading to a tendancy increased in quality of life (P=0.097). Conclusion In addition to demonstrate the feasibility of implementing physical status assessments in MM patients receiving modern first-line therapies, this study also showed alterations in muscle mass. Given the relationship between muscle mass and mortality in other cancer sites, resistance exercise should be implemented as early as possible during treatment