多发性骨髓瘤（MM）是一种常见的造血系统恶性肿瘤，起源于恶性浆细胞克隆。孤立性浆细胞瘤、糖尿病病史和血小板计数被认为是MM的预后因素。但是，一些患者在没有任何预后预测因子的情况下仍然与更糟糕的结局相关。本研究旨在观察首次和第四次化疗周期后单克隆蛋白（M蛋白）的减少率，该减少率被认为是新诊断MM标准危险组的无进展生存期（PFS）的预后因素。调查第一和第四个周期化疗后的M蛋白减少率作为有用的预后因素。包括2010年至2019年期间在丽水市中心医院首次诊断为MM的共计316名患者。所有患者根据2020年国家综合癌症网络（NCCN）V1诊断标准进行诊断。通过Mayo大球蛋白血症分层和风险调整治疗指南进行风险评估。诊断后，164名患者接受了为期四至八个周期的连续诱导化疗治疗评估。对于诱导治疗后无反应的患者，根据NCCN 2020.V1标准进行额外治疗。收集患者的以下基线数据：性别，诊断时年龄，Durie-Salmon分期，谷草-丙氨酸转胺酶，谷草-草酰乙酸转氨酶，降解物激活蛋白，白蛋白/球蛋白比，乳酸脱氢酶，易位（t）（6；14），t（11；14），维持治疗方案，总胆固醇（TC），甘油三酯和磷。通过单变量分析评估所有基线数据和第一至第四个化疗周期后M蛋白的减少率。然后，通过多变量分析评估影响总生存期和PFS的因素。我们发现第一个周期（C1）的减少率和第四个周期（C4）的减少率是PFS的预测因素。然后，比较了具有M蛋白C1减少率≥ 25％与<25％以及≥ 50％与<50％，以及具有M蛋白C4减少率≥ 25％与<25％，≥ 50.％与<50％，以及≥ 75％与<75％之间的PFS。多变量分析揭示年龄 [风险比（HR）：1.059，95％置信区间（CI）：1.033-1.085，P≤0.001]，国际分期系统分期（HR：2.136，95％CI：1.500-3.041，P≤0.001），自体移植（HR：0.201，95％CI：0.069-0.583，P=0.019），TC（HR：0.689，95％CI：0.533-0.891，P=0.019），C1减少率（HR：0.474，95％CI：0.293-0.767，P=0.019）和C4减少率（HR：0.254，95％CI：0.139-0.463，P=0.019）是PFS的预测因素。Kaplan-Meier生存分析和log-rank检验显示，第一周期（≥ 50％）和第四周期（≥ 75％）化疗后M蛋白较高的减少率与较低减少率相比，与较长的PFS相关。在初步诊断中，第一个和第四个化疗周期后M蛋白的较高减少率可以作为MM标准危险组PFS的有利预后因素。©The Author（s) 2023。Baishideng Publishing Group Inc.保留所有权利。

Multiple myeloma (MM) is a common hematologic malignancy that originates from a malignant clone of plasma cells. Solitary plasmacytoma, history of diabetes, and platelet count are considered as prognostic factors for MM. But some patients are still associated with much worse outcomes without any prognostic predictors. This study aimed to observe the reduction rate of monoclonal protein (M protein) after the first and fourth chemotherapy cycles, which is considered as a new prognostic factor for progression-free survival (PFS) in standard-risk group of newly diagnosed MM patients.To investigate the reduction rate of M protein after first and fourth cycle chemotherapy as a useful prognostic factor.A total of 316 patients diagnosed with MM for the first time between 2010 and 2019 at the Lishui Municipal Central Hospital were included. All patients were diagnosed according to the National Comprehensive Cancer Network (NCCN) 2020.V1 diagnostic criteria. The risk assessment was performed by the Mayo Stratification for Macroglobulinemia and Risk-Adapted Therapy guidelines. After diagnosis, 164 patients were evaluated and underwent treatment with four to eight courses of continuous induction chemotherapy. The patients with no response after induction treatment were administered additional therapy following the NCCN 2020.V1 criteria. The following baseline data from the patients were collected: Gender, age at diagnosis, Durie-Salmon stage, glutamic-pyruvic transaminase, glutamic-oxaloacetic transaminase, catabolite activator protein, albumin/globulin ratio, lactate dehydrogenase, translocation (t)(6;14), t(11;14), maintenance regimen, total cholesterol (TC), triglyceride, and phosphorous. All baseline data and the reduction rate of M protein after each chemotherapy cycle from the first to fourth were assessed by univariate analysis. The factors influencing the overall survival and PFS were then assessed by multivariate analysis. We found the first cycle (C1) reduction rate and the fourth cycle (C4) reduction rate as predictors of PFS. Then, PFS was compared between patients with a C1 reduction rate of M protein of ≥ 25% vs < 25% and ≥ 50% vs < 50%, and between patients with a C4 reduction rate of ≥ 25% vs < 25%, ≥ 50% vs < 50%, and ≥ 75% vs < 75%.Multivariate analysis revealed age [hazard ratio (HR): 1.059, 95% confidence interval (95%CI): 1.033-1.085, P ≤ 0.001], International Staging System stage (HR: 2.136, 95%CI: 1.500-3.041, P ≤ 0.001), autotransplantion (HR: 0.201, 95%CI: 0.069-0.583, P = 0.019), TC (HR: 0.689, 95%CI: 0.533-0.891, P = 0.019), C1 reduction rate (HR: 0474, 95%CI: 0.293-0.767, P = 0.019), and C4 reduction rate (HR: 0.254, 95%CI: 0.139-0.463, P = 0.019) as predictors of PFS. The Kaplan-Meier survival analysis and the log-rank tests revealed that a higher reduction rate of M protein after first cycle (≥ 50%) and fourth cycle (≥ 75%) chemotherapy was associated with a longer PFS than the lower one.Higher reduction rates of M protein after the first and fourth chemotherapy cycles can act as advantageous prognostic factors for PFS in standard-risk group of MM patients during initial diagnosis.©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.