Extra copies of chromosome 1q21 (+1q: gain = 3 copies, amp >= 4 copies) are associated with worse outcomes in multiple myeloma (MM). This systematic review assesses the current reporting trends of +1q, the efficacy of existing regimens on +1q, and its prognostic implications in MM randomized controlled trials (RCTs). Pubmed, Embase and Cochrane Registry of RCTs were searched from January 2012 to December 2022. Only MM RCTs were included. A total of 124 RCTs were included, of which 29 (23%) studies reported on +1q. Among them, 10% defined thresholds for +1q, 14% reported survival data separately for gain and amp, and 79% considered +1q a high-risk cytogenetic abnormality. Amongst RCTs that met the primary endpoint showing improvement in progression free survival (PFS), lenalidomide maintenance (Myeloma XI), selinexor (BOSTON), and isatuximab (IKEMA and ICARIA) were shown to improve PFS for patients with evidence of +1q. Some additional RCT’s such as Myeloma XI+ (carfilzomib), ELOQUENT-3 (elotuzumab), and HOVON-65/GMMG-HD4 (bortezomib) met their endpoint showing improvement in PFS and also showed improvement in PFS in the +1q cohort, although the confidence interval crossed 1. All six studies that reported HR for +1q patients vs. without (across both arms) showed worse OS and PFS for +1q. There is considerable heterogeneity in the reporting of +1q. All interventions that have shown to be successful in RCTs and have clearly reported on the +1q subgroup have shown concordant direction of results and benefit of the applied intervention. A more standardized approach to reporting this abnormality is needed.

染色体 1q21 的额外拷贝（+1q：增益 = 3 拷贝，amp >= 4 拷贝）与多发性骨髓瘤 (MM) 的较差结果相关。本系统综述评估了 +1q 目前的报告趋势、现有方案对 +1q 的疗效及其在 MM 随机对照试验 (RCT) 中的预后意义。检索了 2012 年 1 月至 2022 年 12 月期间 Pubmed、Embase 和 Cochrane 注册中心的随机对照试验。仅纳入了多发性骨髓瘤随机对照试验。总共纳入了 124 项随机对照试验，其中 29 项（23%）研究报告了+1q。其中，10% 的人定义了+1q 的阈值，14% 的人分别报告了增益和放大器的生存数据，79% 的人认为+1q 是高风险细胞遗传学异常。在满足主要终点显示无进展生存期 (PFS) 改善的随机对照试验中，来那度胺维持治疗 (骨髓瘤 XI)、selinexor (BOSTON) 和 isatuximab (IKEMA 和 ICARIA) 被证明可以改善 +1q 证据的患者的 PFS。其他一些随机对照试验，例如骨髓瘤 XI+（卡非佐米）、ELOQUENT-3（埃洛妥珠单抗）和 HOVON-65/GMMG-HD4（硼替佐米）达到了终点，显示 PFS 有所改善，并且 +1q 队列中的 PFS 也有所改善，尽管置信区间跨越 1。报告+1q 患者与无患者（双臂）HR 的所有六项研究均显示 +1q 患者的 OS 和 PFS 更差。+1q 的报告存在相当大的异质性。所有在随机对照试验中显示成功并明确报告 +1q 亚组的干预措施均显示出一致的结果方向和所应用干预措施的益处。需要一种更标准化的方法来报告这种异常情况。