阿巴塔塞普（ABT）被认为比其他生物制剂降低感染风险，并且在老年类风湿性关节炎（RA）患者中具有有效性和安全性。然而，关于ABT对老年人更常见的与预后密切相关的恶性肿瘤的影响存在不一致的报道。本研究旨在评估临床实践中ABT在先前患有恶性肿瘤的RA患者中的疗效和安全性。这是一项多中心、回顾性研究。本研究纳入了在横滨两家医院接受ABT治疗的RA患者，截止到2022年5月。根据是否有恶性肿瘤病史（无先前恶性肿瘤：NP组，有先前恶性肿瘤：PM组），将患者分为两组。使用倾向性评分配对比较两组之间的收集参数。本研究纳入了312名患者，其中73名在开始使用ABT时有先前的恶性肿瘤。PM组ABT开始治疗时的年龄显著较高，PM组甲氨蝶呤使用率显著较低，PM组的Steinbrocker分级显著较高。在匹配这三个因素后，每组选取了68名患者。在ABT开始治疗后，两组之间ABT继续率和恶性肿瘤发生率无显著差异。除了这些因素外，根据已知的在RA中与恶性肿瘤相关的风险因素（吸烟史、间质性肺疾病、疾病持续时间、性别和炎症状态）进行匹配，每组选取了40名患者。在ABT开始治疗后，两组之间ABT继续率和恶性肿瘤发生率无显著差异。在我们的临床实践中，ABT在具有恶性肿瘤史的患者中与无恶性肿瘤史的患者一样有效且安全。© 作者（们），2023年。

Abatacept (ABT) is known to lower infection risk than other biologics and is effective and safe in elderly patients with rheumatoid arthritis (RA). However, there were inconsistent reports on the impact of ABT on malignancies which are more common in the elderly and strongly related to prognosis.This study aimed to evaluate the efficacy and safety of ABT in patients with RA with previous malignancy in clinical practice.A multicenter, retrospective study.Patients who received ABT for RA in two hospitals in Yokohama until May 2022 were included in this study. The patients were divided into two groups according to the presence or absence of a history of malignancy (no previous malignancy: NP group, previous malignancy: PM group). The collected parameters were compared between the groups using propensity score matching.In this study, 312 patients were included, of whom 73 had previous malignancies when starting ABT. The age at ABT initiation was significantly higher in the PM group, the rate of methotrexate use was significantly lower in the PM group, and the Steinbrocker stage was significantly higher in the PM group. After matching these 3 factors, 68 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation. In addition to these factors, when matched for smoking history, interstitial lung disease, disease duration, sex, and inflammatory status, which are known risk factors for malignancy in RA, 40 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation.In our clinical practice, ABT was as effective and safe in patients with a history of malignancy as in those without.© The Author(s), 2023.