Sharma Niyati S, Nataraj K S, Choudhary Bibha
Institute of Bioinformatics and Applied Biotechnology (IBAB), Electronic City, Bengaluru, Karnataka, 560100, India.
Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India.
Med Oncol. 2025 Sep 18;42(11):478. doi: 10.1007/s12032-025-03032-5.
Multiple myeloma (MM) exhibits significant genetic heterogeneity with mutations in the MAPK pathway being increasingly recognized as drivers of progression and treatment resistance. This study is the first to employ droplet digital PCR (DD-PCR) on bone marrow formalin-fixed paraffin-embedded (BM-FFPE) tissue to quantify BRAF V600E and NRAS Q61R mutations in MM, and the first such investigation conducted in an Indian MM cohort. Mutations were identified in > 80% of samples. BRAF V600E displayed stage-specific variation, being lowest in intermediate MM and significantly higher in advanced disease (MMII vs MMIII, p = 0.0453). Burden declined after treatment (p = 0.038) and correlated with stage (β = - 36.95, p = 0.0041) and lytic lesions (β = - 25.97, p = 0.0268). NRAS Q61R was enriched in progressive disease (p = 0.02) and showed an upward trend with advancing stage (β = 14.38, p = 0.0686). Higher BRAF and NRAS burdens were associated with reduced 2-year progression-free survival (PFS). We show that DD-PCR applied to BM-FFPE samples is both feasible and informative. However, our study has inherent limitations: DD-PCR measurements can be influenced by sampling biases, droplet variability and FFPE DNA quality. Our single-centre design and small cohort size limit generalizability but demonstrate the potential for DD-PCR to complement sequencing and clinical stratification if validated in larger populations.
多发性骨髓瘤（MM）表现出显著的基因异质性，丝裂原活化蛋白激酶（MAPK）途径中的突变越来越被认为是疾病进展和治疗耐药的驱动因素。本研究首次采用液滴数字PCR（DD-PCR）技术对骨髓福尔马林固定石蜡包埋（BM-FFPE）组织进行检测，以定量MM患者中BRAF V600E和NRAS Q61R突变，且是在印度MM队列中开展的首例此类研究。在超过80%的样本中检测到了突变。BRAF V600E表现出阶段特异性差异，在中期MM中最低，而在晚期疾病中显著更高（MMII期与MMIII期相比，p = 0.0453）。治疗后负担下降（p = 0.038），且与疾病分期（β = - 36.95，p = 0.0041）和溶骨性病变（β = - 25.97，p = 0.0268）相关。NRAS Q61R在进展性疾病中富集（p = 0.02），并随着疾病分期进展呈上升趋势（β = 14.38，p = 0.0686）。较高的BRAF和NRAS负担与2年无进展生存期（PFS）降低相关。我们证明，将DD-PCR应用于BM-FFPE样本既可行又具有信息价值。然而，我们的研究存在固有局限性：DD-PCR测量可能受到抽样偏差、液滴变异性和FFPE DNA质量的影响。我们的单中心设计和小样本队列限制了研究结果的普遍性，但证明了如果在更大规模人群中得到验证，DD-PCR有潜力补充测序和临床分层。
