Department of Medical Oncology, University Medical Center Utrecht (UMCU), Utrecht, The Netherlands.
HUB Organoids B.V, Utrecht, The Netherlands.
J Exp Clin Cancer Res. 2024 Feb 27;43(1):61. doi: 10.1186/s13046-024-02980-6.
The inability to predict treatment response of colorectal cancer patients results in unnecessary toxicity, decreased efficacy and survival. Response testing on patient-derived organoids (PDOs) is a promising biomarker for treatment efficacy. The aim of this study is to optimize PDO drug screening methods for correlation with patient response and explore the potential to predict responses to standard chemotherapies.
We optimized drug screen methods on 5-11 PDOs per condition of the complete set of 23 PDOs from patients treated for metastatic colorectal cancer (mCRC). PDOs were exposed to 5-fluorouracil (5-FU), irinotecan- and oxaliplatin-based chemotherapy. We compared medium with and without N-acetylcysteine (NAC), different readouts and different combination treatment set-ups to capture the strongest association with patient response. We expanded the screens using the optimized methods for all PDOs. Organoid sensitivity was correlated to the patient's response, determined by % change in the size of target lesions. We assessed organoid sensitivity in relation to prior exposure to chemotherapy, mutational status and sidedness.
Drug screen optimization involved excluding N-acetylcysteine from the medium and biphasic curve fitting for 5-FU & oxaliplatin combination screens. CellTiter-Glo measurements were comparable with CyQUANT and did not affect the correlation with patient response. Furthermore, the correlation improved with application of growth rate metrics, when 5-FU & oxaliplatin was screened in a ratio, and 5-FU & SN-38 using a fixed dose of SN-38. Area under the curve was the most robust drug response curve metric. After optimization, organoid and patient response showed a correlation coefficient of 0.58 for 5-FU (n = 6, 95% CI -0.44,0.95), 0.61 for irinotecan- (n = 10, 95% CI -0.03,0.90) and 0.60 for oxaliplatin-based chemotherapy (n = 11, 95% CI -0.01,0.88). Median progression-free survival of patients with resistant PDOs to oxaliplatin-based chemotherapy was significantly shorter than sensitive PDOs (3.3 vs 10.9 months, p = 0.007). Increased resistance to 5-FU in patients with prior exposure to 5-FU/capecitabine was adequately reflected in PDOs (p = 0.003).
Our study emphasizes the critical impact of the screening methods for determining correlation between PDO drug screens and mCRC patient outcomes. Our 5-step optimization strategy provides a basis for future research on the clinical utility of PDO screens.
无法预测结直肠癌患者的治疗反应会导致不必要的毒性、疗效降低和生存时间缩短。基于患者来源的类器官（PDO）的反应测试是一种有前途的治疗效果生物标志物。本研究的目的是优化 PDO 药物筛选方法，以与患者反应相关联，并探索预测标准化疗反应的潜力。
我们优化了 5-氟尿嘧啶（5-FU）、伊立替康和奥沙利铂化疗条件下的 23 个转移性结直肠癌（mCRC）患者的 PDO 药物筛选方法。将 PDO 暴露于 5-FU、伊立替康和奥沙利铂中。我们比较了有和没有 N-乙酰半胱氨酸（NAC）、不同的读出值和不同的联合治疗方案的培养基，以捕捉与患者反应最强的关联。我们使用优化的方法对所有 PDO 进行了扩展筛选。类器官的敏感性与患者的反应相关，通过目标病变大小的变化百分比来确定。我们评估了类器官的敏感性与化疗前暴露、突变状态和侧别之间的关系。
药物筛选优化涉及从培养基中排除 N-乙酰半胱氨酸，并对 5-FU 和奥沙利铂联合筛选进行双相曲线拟合。细胞活力测定（CellTiter-Glo）与 CyQUANT 相当，并且不影响与患者反应的相关性。此外，当以固定的 SN-38 剂量筛选 5-FU 和奥沙利铂时，应用生长率指标可提高相关性，当以比例筛选 5-FU 和 SN-38 时也可提高相关性。曲线下面积是最稳健的药物反应曲线指标。经过优化，PDO 和患者反应之间的相关性为 5-FU（n=6，95%CI-0.44，0.95）的 0.58，伊立替康（n=10，95%CI-0.03，0.90）的 0.61，奥沙利铂化疗（n=11，95%CI-0.01，0.88）的 0.60。对奥沙利铂化疗耐药的患者的 PDO 中位无进展生存期明显短于敏感 PDO（3.3 与 10.9 个月，p=0.007）。对氟尿嘧啶/卡培他滨有预先暴露的患者对 5-FU 的耐药性增加在 PDO 中得到了充分体现（p=0.003）。
本研究强调了筛选方法对于确定 PDO 药物筛选与 mCRC 患者结果之间相关性的关键影响。我们的 5 步优化策略为 PDO 筛选的临床应用研究提供了基础。
