Professor First Affiliated Hospital of Sun Yat-sen University, United States
Introduction: In 2022, Mayo Clinic proposed the Mayo Additive Staging System (MASS), a new staging system for patients with newly diagnosed multiple myeloma (NDMM). Based on the number of risk factors (ISS III, elevated lactate dehydrogenase, 1q gain/ amplification, high-risk IgH translocations, chromosome 17 abnormalities), they were divided into the 3-tier MASS (MASS-3) (no, 1, ≥2 high-risk factors for stage I, II, III, respectively) and 4-tier MASS (MASS-4) (no, 1, 2, ≥3 high-risk factors for stage I, II, III, IV, respectively). Real-world studies have shown that MASS-3 and MASS-4 are suitable for prognostic stratification in Chinese patients with NDMM, but there is no clear evidence of their utility in transplant-eligible patients with NDMM.
Methods: A retrospective analysis of the clinical data of 215 NDMM patients who received "induction therapy-autologous hematopoietic stem cell transplantation (ASCT)" in our center was performed.
Results: The median progression-free survival (PFS) of MASS-3 I, II, and III was 77.7, 87.7, and 50.5 months, respectively(P=0.011), and the median overall survival (OS) was not reached, 109.6, and 69.7 months, respectively(P=0.003). The PFS and OS of patients with MASS-3 III were significantly shorter than those of stage I (P < 0.05). The median PFS of MASS-4 I, II, III, and IV was 77.7, 87.7, 52.6, and 34.5 months, respectively (P=0.004), and the median OS was not reached, 109.6, 106.0, and 40.6 months, respectively (P < 0.001). The PFS and OS of patients with MASS-4 III were significantly shorter than those of stage I (P < 0.05). The PFS of patients with MASS-4 IV was significantly shorter than that of stage I, II, or III (P < 0.001). The OS of stage IV was significantly shorter than that of stage I or II (P < 0.01), and tended to be shorter than that of III (P =0.06). In patients with single ASCT, different ages, and different induction regimens, the prognostic stratification of MASS-4 was also better than that of MASS-3. However, there was no significant difference in PFS and OS between different MASS-3 or MASS-4 stages in patients with tandem ASCT.
Conclusions: Among transplant-eligible patients with NDMM, the prognostic stratification value of MASS-4 was better than that of MASS-3, particularly distinguishing high-risk patients with poor prognosis. Compared with single ASCT, tandem ASCT may overcome the poor prognosis of high-risk MASS patients.
