Malignant pleural effusion (MPE) presents a severe medical condition in patients with advanced breast cancer (BC). We applied organoid culture technology to culture preoperative puncture specimen and corresponding surgical specimen-derived tumor cells from early BC patients and pleural effusion-derived tumor cells from advanced BC patients with MPE to study whether in vitro models could predict therapies of clinical patients. We successfully expanded pleural effusion-derived tumor organoids from 1 advanced triple-negative breast cancer (TNBC) patient with MPE which had been continuously propagated for more than 3 months. The organoids matched the histological characteristics of primary BC and metastatic supraclavicular lymph nodes by H&E staining and retained negative expression of TNBC biomarkers: estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and positive expression of antigen Ki-67. Multiple mutations were detected from this advanced TNBC patient with MPE by high-throughput sequencing of metastatic supraclavicular lymph node and the plasma sample. We performed the 3D drug screening tests combined with the clinical medication situation of this patient. The pleural effusion-derived tumor organoids were sensitive to capecitabine (IC₅₀ 1.580 μmol) and everolimus (IC₅₀ 4.008 μmol) single-agent treatments. The sensitivity to capecitabine was consistent with the clinical treatment response of this patient for capecitabine and with the sequencing results that reported MTHFR gene polymorphism mutation and TYMS −6bp/−6bp polymorphism mutation indicating effectiveness to fluorouracil. Our results suggested that an effective platform for ex vivo pleural effusion-derived tumor organoids from advanced TNBC patients with MPE could be used to identify treatment options and explore the clinicopathological characteristics of these patients.

恶性胸腔积液 (MPE) 是晚期乳腺癌 (BC) 患者的一种严重疾病。我们应用类器官培养技术对早期 BC 患者的术前穿刺标本和相应的手术标本来源的肿瘤细胞以及晚期 BC 合并 MPE 的胸腔积液来源的肿瘤细胞进行了体外培养研究模型可以预测临床患者的治疗。我们成功地扩展了 1 名患有 MPE 的晚期三阴性乳腺癌 (TNBC) 患者的胸腔积液衍生的肿瘤类器官，该患者已连续繁殖超过 3 个月。这些类器官通过 H&E 染色与原发性 BC 和转移性锁骨上淋巴结的组织学特征相匹配，并保留了 TNBC 生物标志物的阴性表达：雌激素受体、孕激素受体、人表皮生长因子受体 2 和抗原 Ki-67 的阳性表达。通过对转移性锁骨上淋巴结和血浆样本进行高通量测序，从这名患有 MPE 的晚期 TNBC 患者身上检测到多种突变。我们结合该患者的临床用药情况进行了3D药物筛选试验。₅₀ 1.580 μmol) 和依维莫司 (IC ₅₀ 4.008 μmol) 单药治疗。对卡培他滨的敏感性与该患者对卡培他滨的临床治疗反应一致，并与报告 MTHFR 基因多态性突变和 TYMS -6bp/-6bp 多态性突变的测序结果一致，表明对氟尿嘧啶的有效性。我们的结果表明，来自患有 MPE 的晚期 TNBC 患者的离体胸腔积液衍生的肿瘤类器官的有效平台可用于确定治疗方案并探索这些患者的临床病理特征。