[A clinical retrospective analysis of newly diagnosed multiple myeloma patients with systemic light chain amyloidosis].

Objective: To analyze the clinical characteristics, treatment response, and prognosis of newly diagnosed symptomatic multiple myeloma (MM) patients with systemic light chain amyloidosis (AL) . Methods: The clinical data of 160 patients with newly diagnosed MM treated at the First Affiliated Hospital of Soochow University from January 1, 2017 to October 31, 2018, were retrospectively analyzed. According to the histopathological biopsy results of bone marrow, skin, and other tissues, the patients were divided into two groups according to whether amyloidosis was combined or not, namely, the MM+AL group and the MM group. The clinical characteristics and treatment responses of the two groups were compared. Results: Among the 160 patients with newly diagnosed MM, there were 42 cases in the MM+AL group and 118 cases in the MM group. In terms of clinical features, the involved light chain and non-involved light chain (dFLC) in the MM+AL group was significantly higher than that in the MM group ( P =0.039) . After induction treatment, the MM+AL group had a higher overall response rate (85.7% vs 79.7%, P <0.05) and higher excellent partial response (76.2% vs 55.1%, P <0.05) . After a median follow-up of 26 (0.25-41) months, there was no significant difference in the progression free survival and overall survival (OS) between the two groups ( P >0.05) . The OS of patients in autologous hematopoietic stem cell transplantation group was better than that in non transplantation group ( P <0.05) .The prognosis of patients with cardiac involvement in the MM+AL group was significantly worse than that in the MM group and MM+AL group without cardiac involvement ( P <0.001) , with a median OS of only 13 months. Conclusion: The differential diagnosis between the MM+AL and MM groups requires histopathology, particularly for patients with significantly increased dFLC. The overall remission rate of patients in MM+AL group after 4 courses of induction chemotherapy was higher than that in MM group. The prognosis of patients with cardiac involvement in MM+AL group was poor.