Department of Medicine, Stanford University School of Medicine, Stanford, California.
Department of Medicine, Division of Blood and Marrow Transplantation and Cellular Therapy, Stanford University School of Medicine, Stanford, California.
Transplant Cell Ther. 2021 May;27(5):405.e1-405.e6. doi: 10.1016/j.jtct.2021.02.026. Epub 2021 Feb 25.
Autologous hematopoietic stem cell transplantation (ASCT) is a standard treatment for multiple myeloma (MM). Consensus guidelines recommend collecting sufficient stem cells in case there is a need for stem cell boost for delayed/poor engraftment or for future second ASCT. However, collecting and storing backup stem cells in all patients requires significant resources and cost, and the rates of backup stem cell utilization are not well studied. We sought to examine the utilization of backup stem cells (BSCs) in patients with MM undergoing ASCT. Patients with MM aged ≥18 years old who underwent first ASCT at our institution from January 2010 through December 2015 and collected sufficient stem cells for at least 2 transplants were included in this single-center retrospective study. This timeframe was selected to allow for adequate follow-up. A total of 393 patients were included. The median age was 58 years (range, 25-73). After a median follow-up of 6 years, the median progression-free survival (PFS) of the cohort was 3 years. Sixty-one percent (n = 240) of patients progressed or relapsed. Chemotherapy-based mobilization was used in almost all patients (98%). The median total CD34+ cells collected was 18.2 × 10/kg (range, 3.4-112.4). A median of 5.7 × 10 CD34+ cells/kg (range, 1.8-41.9) was infused during the first ASCT, and a median of 10.1 × 10 CD34+ cells/kg (range, 1.5-104.5) was cryopreserved for future use. Of the patients, 6.9% (n = 27) used backup stem cells, with 2.3% (n = 10) using them for stem cell boost, 4.6% (n = 18) for a second salvage ASCT, including 1 patient for both stem cell boost and second ASCT. Rates of backup stem cell use among patients aged <60, 60-69, and ≥70 years were 7.8%, 5.7%, and 5.9%, respectively. There was a trend toward higher rates of backup stem cell use for second ASCT in patients who were younger, had suboptimal disease control at time of first ASCT, and longer PFS. The median dose of stem cell boost given was 5.6 × 10 CD34+ cells/kg (range, 1.9-20). The median time from stem cell boost to neutrophil, hemoglobin, and platelet engraftment was 4 (range, 2-11), 15 (range, 4-34), and 12 (range, 0-34) days, respectively. Lower CD34+ dose and older age at time of ASCT predicted need for stem cell boost. With new salvage therapies for relapsed MM, the rates of second ASCT are very low. The low rates of use suggest that institutional policies regarding universal BSC collection and long-term storage should be reassessed and individualized. However, need for stem cell boost in 2.3% of patients may present a challenge to that.
自体造血干细胞移植（ASCT）是多发性骨髓瘤（MM）的标准治疗方法。共识指南建议在需要干细胞助推以延迟/改善植入或进行未来的第二次 ASCT 的情况下，收集足够的干细胞。然而，在所有患者中收集和储存备用干细胞需要大量资源和成本，并且备用干细胞的利用率尚未得到很好的研究。我们旨在研究接受 ASCT 的 MM 患者中备用干细胞（BSC）的利用情况。
本单中心回顾性研究纳入了 2010 年 1 月至 2015 年 12 月在我院接受首次 ASCT 且年龄≥18 岁的 MM 患者，这些患者至少采集了足够进行 2 次移植的干细胞。选择此时间范围是为了确保有足够的随访时间。共有 393 名患者纳入本研究。中位年龄为 58 岁（范围，25-73）。中位随访 6 年后，队列的中位无进展生存期（PFS）为 3 年。61%（n=240）的患者进展或复发。几乎所有患者（98%）均接受基于化疗的动员。中位采集的总 CD34+细胞数为 18.2×106/kg（范围，3.4-112.4）。首次 ASCT 期间输注了中位数为 5.7×10 CD34+细胞/kg（范围，1.8-41.9），并冷冻保存了中位数为 10.1×10 CD34+细胞/kg（范围，1.5-104.5）以备将来使用。6.9%（n=27）的患者使用了备用干细胞，其中 2.3%（n=10）用于干细胞助推，4.6%（n=18）用于第二次挽救性 ASCT，包括 1 例患者同时进行了干细胞助推和第二次 ASCT。年龄<60、60-69 和≥70 岁的患者备用干细胞使用率分别为 7.8%、5.7%和 5.9%。在年龄较小、首次 ASCT 时疾病控制不理想和 PFS 较长的患者中，第二次 ASCT 使用备用干细胞的比例呈上升趋势。干细胞助推的中位剂量为 5.6×10 CD34+细胞/kg（范围，1.9-20）。从干细胞助推到中性粒细胞、血红蛋白和血小板植入的中位时间分别为 4（范围，2-11）、15（范围，4-34）和 12（范围，0-34）天。较低的 CD34+剂量和 ASCT 时的年龄较大预测需要进行干细胞助推。随着复发 MM 的新挽救疗法的出现，第二次 ASCT 的比例非常低。如此低的使用率表明，应重新评估和个体化机构关于普遍采集和长期储存备用干细胞的政策。然而，2.3%的患者需要干细胞助推可能会带来挑战。
