Challenges in validation of combination treatment strategies for CRC using patient-derived organoids.

Patient-derived organoids (PDOs) established from tissues from various tumor types gave the foundation of ex vivo models to screen and/or validate the activity of many cancer drug candidates. Due to their phenotypic and genotypic similarity to the tumor of which they were derived, PDOs offer results that effectively complement those obtained from more complex models. Yet, their potential for predicting sensitivity to combination therapy remains underexplored. In this review, we discuss the use of PDOs in both validation and optimization of multi-drug combinations for personalized treatment strategies in CRC. Moreover, we present recent advancements in enriching PDOs with diverse cell types, enhancing their ability to mimic the complexity of in vivo environments. Finally, we debate how such sophisticated models are narrowing the gap in personalized medicine, particularly through immunotherapy strategies and discuss the challenges and future direction in this promising field.

Benboubker V ，Ramzy GM ，Jacobs S ，Nowak-Sliwinska P ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Organoids as a biomarker for personalized treatment in metastatic colorectal cancer: drug screen optimization and correlation with patient response.

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.

Smabers LP ，Wensink E ，Verissimo CS ，Koedoot E ，Pitsa KC ，Huismans MA ，Higuera Barón C ，Doorn M ，Valkenburg-van Iersel LB ，Cirkel GA ，Brousali A ，Overmeer R ，Koopman M ，Braat MN ，Penning de Vries B ，Elias SG ，Vries RG ，Kranenburg O ，Boj SF ，Roodhart JM ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Emerging Prospects for the Study of Colorectal Cancer Stem Cells using Patient-derived Organoids.

Human colorectal cancer (CRC) patient-derived organoids (PDOs) are a powerful ex vivo platform to directly assess the impact of molecular alterations and therapies on tumor cell proliferation, differentiation, response to chemotherapy, tumor-microenvironment interactions, and other facets of CRC biology. Next-generation sequencing studies have demonstrated that CRC is a highly heterogeneous disease with multiple distinct subtypes. PDOs are a promising new tool to study CRC due to their ability to accurately recapitulate their source tumor and thus reproduce this heterogeneity. This review summarizes the state-of-the-art for CRC PDOs in the study of cancer stem cells (CSCs) and the cancer stem cell niche. Areas of focus include the relevance of PDOs to understanding CSC-related paracrine signaling, identifying interactions between CSCs and the tumor microenvironment, and modeling CSC-driven resistance to chemotherapies and targeted therapies. Finally, we summarize current findings regarding the identification and verification of CSC targets using PDOs and their potential use in personalized medicine.

Ding L ，Yang Y ，Lu Q ，Cao Z ，Weygant N ... -  《-》

Implementing patient derived organoids in functional precision medicine for patients with advanced colorectal cancer.

Patient Derived Organoids (PDOs) emerged as the best technology to develop ex vivo tumor avatars. Whether drug testing on PDOs to identify efficient therapies will bring clinical utility by improving patient survival remains unclear. To test this hypothesis in the frame of clinical trials, PDO technology faces three main challenges to be implemented in routine clinical practices: i) generating PDOs with a limited amount of tumor material; ii) testing a wide panel of anti-cancer drugs; and iii) obtaining results within a time frame compatible with patient disease management. We aimed to address these challenges in a prospective study in patients with colorectal cancer (CRC). Fresh surgical or core needle biopsies were obtained from patients with CRC. PDOs were established and challenged with a panel of 25 FDA-approved anti-cancer drugs (chemotherapies and targeted therapies) to establish a scoring method ('chemogram') identifying in vitro responders. The results were analyzed at the scale of the cohort and individual patients when the follow-up data were available. A total of 25 PDOs were successfully established, harboring 94% concordance with the genomic profile of the tumor they were derived from. The take-on rate for PDOs derived from core needle biopsies was 61.5%. A chemogram was obtained with a 6-week median turnaround time (range, 4-10 weeks). At least one hit (mean 6.16) was identified for 92% of the PDOs. The number of hits was inversely correlated to disease metastatic dissemination and the number of lines of treatment the patient received. The chemograms were compared to clinical data obtained from 8 patients and proved to be predictive of their response with 75% sensitivity and specificity. We show that PDO-based drug tests can be achieved in the frame of routine clinical practice. The chemogram could provide clinicians with a decision-making tool to tailor patient treatment. Thus, PDO-based functional precision oncology should now be tested in interventional trials assessing its clinical utility for patients who do not harbor activable genomic alterations or have developed resistance to standard of care treatments.

Cartry J ，Bedja S ，Boilève A ，Mathieu JRR ，Gontran E ，Annereau M ，Job B ，Mouawia A ，Mathias P ，De Baère T ，Italiano A ，Besse B ，Sourrouille I ，Gelli M ，Bani MA ，Dartigues P ，Hollebecque A ，Smolenschi C ，Ducreux M ，Malka D ，Jaulin F ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Patient-Derived Organoids from Multiple Colorectal Cancer Liver Metastases Reveal Moderate Intra-patient Pharmacotranscriptomic Heterogeneity.

Molecular tumor heterogeneity may have important implications for the efficacy of targeted therapies in metastatic cancers. Inter-metastatic heterogeneity of sensitivity to anticancer agents has not been well explored in colorectal cancer. We established a platform for ex vivo pharmacogenomic profiling of patient-derived organoids (PDO) from resected colorectal cancer liver metastases. Drug sensitivity testing (n = 40 clinically relevant agents) and gene expression profiling were performed on 39 metastases from 22 patients. Three drug-response clusters were identified among the colorectal cancer metastases, based primarily on sensitivities to EGFR and/or MDM2 inhibition, and corresponding with RAS mutations and TP53 activity. Potentially effective therapies, including off-label use of drugs approved for other cancer types, could be nominated for eighteen patients (82%). Antimetabolites and targeted agents lacking a decisive genomic marker had stronger differential activity than most approved chemotherapies. We found limited intra-patient drug sensitivity heterogeneity between PDOs from multiple (2-5) liver metastases from each of ten patients. This was recapitulated at the gene expression level, with a highly proportional degree of transcriptomic and pharmacological variation. One PDO with a multi-drug resistance profile, including resistance to EGFR inhibition in a RAS-mutant background, showed sensitivity to MEK plus mTOR/AKT inhibition, corresponding with low-level PTEN expression. Intra-patient inter-metastatic pharmacological heterogeneity was not pronounced and ex vivo drug screening may identify novel treatment options for metastatic colorectal cancer. Variation in drug sensitivities was reflected at the transcriptomic level, suggesting potential to develop gene expression-based predictive signatures to guide experimental therapies.

Bruun J ，Kryeziu K ，Eide PW ，Moosavi SH ，Eilertsen IA ，Langerud J ，Røsok B ，Totland MZ ，Brunsell TH ，Pellinen T ，Saarela J ，Bergsland CH ，Palmer HG ，Brudvik KW ，Guren T ，Dienstmann R ，Guren MG ，Nesbakken A ，Bjørnbeth BA ，Sveen A ，Lothe RA ... -  《-》