Organoids from colorectal peritoneal metastases as a platform for improving hyperthermic intraperitoneal chemotherapy

Abstract

Background Patients with peritoneal metastases from colorectal cancer have a poor prognosis. If the intraperitoneal tumour load is limited, patients may be eligible for cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC). This treatment has improved overall survival, but recurrence rates are high. The aim of this study was to create a preclinical platform for the development of more effective intraperitoneal chemotherapy strategies. Methods Using organoid technology, five tumour cultures were generated from malignant ascites and resected peritoneal metastases. These were used in an in vitro HIPEC model to assess sensitivity to mitomycin C (MMC) and oxaliplatin, the drugs used most commonly in HIPEC. The model was also used to test a rational combination treatment involving MMC and inhibitors of the checkpoint kinase ATR. Results MMC was more effective in eliminating peritoneal metastasis‐derived organoids than oxaliplatin at clinically relevant concentrations. However, the drug concentrations required to eliminate 50 per cent of the tumour cells (IC50) were higher than the median clinical dose in two of five organoid lines for MMC, and all five lines for oxaliplatin, indicating a general resistance to monotherapy. ATR inhibition increased the sensitivity of all peritoneal metastasis‐derived organoids to MMC, as the IC50 decreased 2·6–12·4‐fold to well below concentrations commonly attained in clinical practice. Live‐cell imaging and flow cytometric analysis showed that ATR inhibition did not release cells from MMC‐induced cell cycle arrest, but caused increased replication stress and accelerated cell death. Conclusion Peritoneal metastasis‐derived organoids can be used to evaluate existing HIPEC regimens on an individual‐patient level and for development of more effective treatment strategies. Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) has improved prognosis of patients with peritoneal metastases from colorectal cancer, but disease recurrence is common. More effective and personalized HIPEC is urgently needed. Organoid technology is frequently used for drug screens, as patient‐derived organoids can accurately predict clinical therapeutic response in vitro.A panel of organoids was established from peritoneal metastases from colorectal cancer and used to develop a model for testing HIPEC regimens in vitro. Patient‐derived organoids differed in sensitivity to commonly used chemotherapeutics, in line with variable clinical outcomes following cytoreductive surgery–HIPEC. Combining MMC with an ATR inhibitor improved the efficacy of MMC.Peritoneal metastasis‐derived organoids can be used as a platform to test novel (combination) strategies that increase HIPEC efficacy. In the future, organoids could be used to select patent‐tailored HIPEC regimens.

The Temperature-Dependent Effectiveness of Platinum-Based Drugs Mitomycin-C and 5-FU during Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Colorectal Cancer Cell Lines

“…IC50 values of MMC are much lower than clinical concentrations in four out of five cell lines, in particular within CMS4 cell lines and the CRC organoid model. Our results suggest, similar to the results of Ubink and colleagues [39], that MMC is more effective in reducing cell viability than oxaliplatin at clinically relevant concentrations, when treated for exposure times matching current HIPEC regimes. Ubink et al treated peritoneal metastases-derived organoids with oxaliplatin (30 min) or MMC (90 min), both at 42 • C [39].…”

“…Our results suggest, similar to the results of Ubink and colleagues [39], that MMC is more effective in reducing cell viability than oxaliplatin at clinically relevant concentrations, when treated for exposure times matching current HIPEC regimes. Ubink et al treated peritoneal metastases-derived organoids with oxaliplatin (30 min) or MMC (90 min), both at 42 • C [39]. Results showed that IC50 values were higher than the median clinical dose in two of five organoid lines for MMC, and all five lines for oxaliplatin, suggesting that MMC is more effective when using a 90-min exposure time, which is three times longer than the exposure time used for oxaliplatin.…”

Short-term oxaliplatin exposure according to established hyperthermic intraperitoneal chemotherapy (HIPEC) protocols lacks effectivenessin vitroandex vivo

“…2e), procedure; (13,14)) as well as based on data from own HIPEC conduct (~90 µg/ml ≙ 227 µM) (16). This dose range is also in line with previous published HIPEC in vitro models (17).…”

Effect of intraperitoneal chemotherapy concentration on morbidity and survival

“…Variable intraperitoneal volumes may also have had a confounding effect. A recent study with patient‐derived organoids did, however, find that currently used concentrations might be insufficient for complete eradication of all malignant cells. This merits further investigation, as drug concentrations may be critical as new agents are introduced.…”