Pulmonary function abnormalities are common in patients with multiple myeloma and are independently associated with worse outcome.

Pre-existing pulmonary disease may affect treatment choices, toxicity, and survival of patients with multiple myeloma (MM). However, data on the prognostic value of pulmonary function tests (PFTs) in myeloma patients' outcome, at the time of initial assessment of newly diagnosed patients, are scarce. Here, we prospectively performed PFTs in 121 newly diagnosed MM patients, before initiation of treatment, and we evaluated possible associations of lung function with their outcomes. Fifty-four patients (44.63%) had either obstructive or restrictive pulmonary function defects, even among those not reporting a history of lung disease. The survival was significantly worse in those with obstructive pulmonary defect (median OS 32.8 months) vs. those with restrictive (median OS 52.5 months) or normal lung function (median not reached, 3-year survival 76%) (p = 0.013), independently of other myeloma-related factors. Forced vital capacity (FVC) (lt) (p = 0.012), forced expiratory volume in 1 s (FEV1) (lt) (p = 0.018), peak expiratory flow (PEF) (lt/min) (p = 0.008), carbon monoxide diffusion capacity (DLCO) (p = 0.012), and expiratory/inspiratory pressures (Pe) (kPa) (p = 0.032)/(Pi) (kPa) (p = 0.023) were significantly associated with OS. Myeloma-related factors associated with survival included ISS stage (p = 0.008), hypercalcemia (p = 0.064), and high-risk cytogenetics (p = 0.004). In the multivariate analysis, only the presence of high-risk cytogenetics and presence of either or both PEF and DLCO < 65% of predicted were independent prognostic factors. We conclude that PEF and DLCO could be useful in the initial assessment of newly diagnosed MM patients as significant predictors of survival. Further research is needed to evaluate if respiratory screening should be included in the routine initial evaluation of myeloma patients, despite the presence or absence of respiratory symptoms or abnormal clinical respiratory examination.