myeloma prognosisasymptomatic myeloma prognosismalignant myeloma prognosissmouldering myeloma prognosissmoldering myeloma prognosismyeloma prognosis in the elderlystage 2 myeloma prognosisplasma myeloma prognosismetastatic multiple myeloma prognosisaggressive multiple myeloma prognosissmoldering multiple myeloma prognosisstage 4 multiple myeloma prognosis