Objective To investigate the clinical characteristics and prognosis of patients with newly diagnosed multiple myeloma (NDMM) with thrombocytopenia.

Methods Clinical data of 529 patients with NDMM admitted to The Second Hospital of Shanxi Medical University between January 2012 and December 2021 were retrospectively analyzed. The patients were categorized into thrombocytopenia and normal platelet count groups based on their platelet count levels.

Results A total of 529 patients with NDMM were included in this study, with 108 (20.42%) patients in the thrombocytopenia group. The median progression-free survival (mPFS) was 30.64 months (95% confidence interval CI: 23.43-37.85) in the thrombocytopenia group, which was shorter than that in the normal platelet count group (41.39 months 95%CI: 37.37-45.39, P=0.002). The median overall survival (mOS) was 40.59 months (95%CI: 30.61-50.57) in the thrombocytopenia group, which was shorter than that in the normal platelet count group (60.92 months 95%CI: 54.54-67.29, P<0.001). Multivariate Cox regression analysis identified thrombocytopenia as a risk factor for OS in patients with NDMM (HR=1.238 95%CI: 1.16-1.952, P=0.03).

Conclusions The prognosis of patients with NDMM with thrombocytopenia was worse than that of patients with NDMM who had normal platelet levels. Thrombocytopenia may serve as a poor prognostic indicator for NDMM.