Hazel Lote

Patient-derived organoids model treatment response of metastatic gastrointestinal cancers

Cancer organoids to model therapy response Cancer organoids are miniature, three-dimensional cell culture models that can be made from primary patient tumors and studied in the laboratory. Vlachogiannis et al. asked whether such “tumor-in-a-dish” approaches can be used to predict drug responses in the clinic. They generated a live organoid biobank from patients with metastatic gastrointestinal cancer who had previously been enrolled in phase I or II clinical trials. This allowed the authors to compare organoid drug responses with how the patient actually responded in the clinic. Encouragingly, the organoids had similar molecular profiles to those of the patient tumor, reinforcing their value as a platform for drug screening and development. Science, this issue p. 920 Organoids can recapitulate patient responses in the clinic, with potential for drug screening and personalized medicine. Patient-derived organoids (PDOs) have recently emerged as robust preclinical models; however, their potential to predict clinical outcomes in patients has remained unclear. We report on a living biobank of PDOs from metastatic, heavily pretreated colorectal and gastroesophageal cancer patients recruited in phase 1/2 clinical trials. Phenotypic and genotypic profiling of PDOs showed a high degree of similarity to the original patient tumors. Molecular profiling of tumor organoids was matched to drug-screening results, suggesting that PDOs could complement existing approaches in defining cancer vulnerabilities and improving treatment responses. We compared responses to anticancer agents ex vivo in organoids and PDO-based orthotopic mouse tumor xenograft models with the responses of the patients in clinical trials. Our data suggest that PDOs can recapitulate patient responses in the clinic and could be implemented in personalized medicine programs.

PD-1 and PD-L1 blockade in gastrointestinal malignancies

Immunotherapy represents a major breakthrough in cancer therapy in recent years. Immune-checkpoint blockade using PD-1 and PD-L1 antibodies appears to be one of the most promising immunotherapy approaches. Immunotherapy differs from conventional cancer treatment because of its ability to produce durable responses in some patients. In this review article, we explore the available evidence and summarise current clinical trials for PD-1 and PD-L1 blockade in gastrointestinal malignancies. The challenge now is to develop strategies to increase the efficacy of PD-1 and PD-L1 blockade in gastrointestinal cancer patients, such as combination therapy with chemotherapy, radiotherapy or other immunotherapy, along with validating biomarkers to select patients and personalise treatment.

Revised Choi Imaging Criteria Correlate with Clinical Outcomes in Patients with Metastatic Renal Cell Carcinoma Treated with Sunitinib

PURPOSE To compare revised Choi criteria that incorporate concurrent size and attenuation changes at early follow-up imaging with Response Evaluation Criteria in Solid Tumors ( RECIST Response Evaluation Criteria in Solid Tumors ) 1.1 and original Choi criteria in stratification of clinical outcomes in patients with metastatic renal cell carcinoma ( mRCC metastatic renal cell carcinoma ) treated with sunitinib. MATERIALS AND METHODS Institutional review board approved this retrospective study and waived informed consent. Baseline and first follow-up computed tomographic scans in 69 patients (50 men, 19 women; mean age, 60.3 years; range, 19-83 years) with mRCC metastatic renal cell carcinoma treated with sunitinib from October 1, 2008, to March 1, 2013, were evaluated for tumor response by using RECIST Response Evaluation Criteria in Solid Tumors 1.1, original Choi criteria, and revised Choi criteria. Correlations with overall survival ( OS overall survival ) and progression-free survival ( PFS progression-free survival ) were compared and stratified according to each radiologic criteria with Kaplan-Meier and multivariate Cox regression analysis. RESULTS Median follow-up time was 29.7 months (95% confidence interval [ CI confidence interval ]: 18.9, 45.9). Response according to revised Choi criteria was independently correlated with OS overall survival (hazard ratio, 0.47 [95% CI confidence interval : 0.23, 0.99]; P = .046) and PFS progression-free survival (hazard ratio, 0.53 [95% CI confidence interval : 0.29, 0.99]; P = .047). Response according to RECIST Response Evaluation Criteria in Solid Tumors was not significantly correlated with OS overall survival (hazard ratio, 0.65 [95% CI confidence interval : 0.27, 1.58]; P = .344) or PFS progression-free survival (hazard ratio, 0.89 [95% CI confidence interval : 0.42, 1.91]; P = .768). Response according to original Choi criteria was not significantly correlated with OS overall survival (hazard ratio, 0.60 [95% CI confidence interval : 0.32, 1.11]; P = .106) or PFS progression-free survival (hazard ratio, 0.59 [95% CI confidence interval : 0.34, 1.02]; P = .060). Median OS overall survival and PFS progression-free survival in responders according to revised Choi criteria was 39.4 months (95% CI confidence interval : 9.1, upper limit not estimated) and 13.7 months (95% CI confidence interval : 6.4, 24.6), respectively, compared with 12.8 months (95% CI confidence interval : 8.7, 18.0) and 5.3 months (95% CI confidence interval : 3.9, 8.4), respectively, in nonresponders. CONCLUSION Contemporaneous reduction in tumor size and attenuation were correlated with favorable clinical outcomes. Response according to revised Choi criteria showed better correlation with clinical outcomes compared with that according to RECIST Response Evaluation Criteria in Solid Tumors or original Choi criteria in patients with mRCC metastatic renal cell carcinoma treated with sunitinib.

Functional imaging and circulating biomarkers of response to regorafenib in treatment-refractory metastatic colorectal cancer patients in a prospective phase II study

Objective Regorafenib demonstrated efficacy in patients with metastatic colorectal cancer (mCRC). Lack of predictive biomarkers, potential toxicities and cost-effectiveness concerns highlight the unmet need for better patient selection. Design Patients with RAS mutant mCRC with biopsiable metastases were enrolled in this phase II trial. Dynamic contrast-enhanced (DCE) MRI was acquired pretreatment and at day 15 post-treatment. Median values of volume transfer constant (Ktrans), enhancing fraction (EF) and their product KEF (summarised median values of Ktrans× EF) were generated. Circulating tumour (ct) DNA was collected monthly until progressive disease and tested for clonal RAS mutations by digital-droplet PCR. Tumour vasculature (CD-31) was scored by immunohistochemistry on 70 sequential tissue biopsies. Results Twenty-seven patients with paired DCE-MRI scans were analysed. Median KEF decrease was 58.2%. Of the 23 patients with outcome data, >70% drop in KEF (6/23) was associated with higher disease control rate (p=0.048) measured by RECIST V. 1.1 at 2 months, improved progression-free survival (PFS) (HR 0.16 (95% CI 0.04 to 0.72), p=0.02), 4-month PFS (66.7% vs 23.5%) and overall survival (OS) (HR 0.08 (95% CI 0.01 to 0.63), p=0.02). KEF drop correlated with CD-31 reduction in sequential tissue biopsies (p=0.04). RAS mutant clones decay in ctDNA after 8 weeks of treatment was associated with better PFS (HR 0.21 (95% CI 0.06 to 0.71), p=0.01) and OS (HR 0.28 (95% CI 0.07–1.04), p=0.06). Conclusions Combining DCE-MRI and ctDNA predicts duration of anti-angiogenic response to regorafenib and may improve patient management with potential health/economic implications.

Effect of glandular metastases on overall survival of patients with metastatic clear cell renal cell carcinoma in the antiangiogenic therapy era.

BACKGROUND Glandular metastases (GMs) (pancreas, breast, parotid, thyroid, or contralateral adrenal) are rare in metastatic clear cell renal cell carcinoma (mccRCC). In a multicenter study we have assessed outcome from mccRCC with or without GMs. PATIENTS AND METHODS Patients with mccRCC and GM or non-GM (NGM) at first presentation of mccRCC, treated at 9 European centers (5 French, 3 UK, and 1 Belgian centers) between January 2004 and October 2013, were retrospectively analyzed. Association between overall survival (OS) and site of metastases was assessed using the log-rank test for univariate analysis and the chi-square test for multivariable Cox regression. RESULTS In all, 138 patients with GM mccRCC and 420 with NGM mccRCC were included; 37.2% patients with GM had Memorial Sloan-Kettering Cancer Center (MSKCC)-favorable risk vs. 18% NGM patients; 10.7% patients with GM had MSKCC-poor risk vs. 27% NGM patients (P<0.0001). Median interval from metastases to treatment was 4.2 months (range: 0-221.3mo). Median OS was 61.5 months (51.4-81.6mo) for GM and 37.4 months (31.3-42mo) for NGM (hazard ratio [HR] = 1.7; 95% CI = 1.3-2.2, P<0.001). In univariate OS analysis, age, delay between initial diagnosis and metastases, MSKCC, bone/lung metastases, and GM or NGM group were significant parameters (P<0.001). In multivariate analysis, adjusted according to MSKCC risk group, NGM vs. GM was a strong prognostic factor (HR = 1.4; 95% CI = 1.0-1.8, P=0.026); bone or liver metastases were also significant (HR = 1.3; 95% CI = 1.1-1.7, P<0.02; HR = 1.4; 95% CI = 1.1-1.7, P<0.02, respectively). Even in patients without bone or liver metastases, GM status was significant (HR = 1.8; 95% CI = 1.2-2.7, P<0.004). CONCLUSIONS This large retrospective study shows that the presence of at least 1 GM site in development of mccRCC was associated with a significantly longer OS. The presence of GMs vs. NGM disease was an independent prognostic factor for survival irrespective of the presence or absence of bone or liver metastases. This finding could affect daily practice in which patients with mccRCC and GMs should receive more aggressive treatment with a potential for long-term survival. The causal mechanisms for this improved prognosis in GM mccRCC would be evaluated in translational studies.

MicroRNA 193b-3p as a predictive biomarker of chronic kidney disease in patients undergoing radical nephrectomy for renal cell carcinoma

Background:A significant proportion of patients undergoing radical nephrectomy (RN) for clear-cell renal cell carcinoma (RCC) develop chronic kidney disease (CKD) within a few years following surgery. Chronic kidney disease has important health, social and economic impact and no predictive biomarkers are currently available. MicroRNAs (miRs) are small non-coding RNAs implicated in several pathological processes.Methods:Primary objective of our study was to define miRs whose deregulation is predictive of CKD in patients treated with RN. Ribonucleic acid from formalin-fixed paraffin embedded renal parenchyma (cortex and medulla isolated separately) situated >3 cm from the matching RCC was tested for miR expression using nCounter NanoString technology in 71 consecutive patients treated with RN for RCC. Validation was performed by RT–PCR and in situ hybridisation. End point was post-RN CKD measured 12 months post-operatively. Multivariable logistic regression and decision curve analysis were used to test the statistical and clinical impact of predictors of CKD.Results:The overexpression of miR-193b-3p was associated with high risk of developing CKD in patients undergoing RN for RCC and emerged as an independent predictor of CKD. The addition of miR-193b-3p to a predictive model based on clinical variables (including sex and estimated glomerular filtration rate) increased the sensitivity of the predictive model from 81 to 88%. In situ hybridisation showed that miR-193b-3p overexpression was associated with tubule-interstitial inflammation and fibrosis in patients with no clinical or biochemical evidence of pre-RN nephropathy.Conclusions:miR-193b-3p might represent a useful biomarker to tailor and implement surveillance strategies for patients at high risk of developing CKD following RN.

Carbon dating cancer: defining the chronology of metastatic progression in colorectal cancer.

Background Patients often ask oncologists how long a cancer has been present before causing symptoms or spreading to other organs. The evolutionary trajectory of cancers can be defined using phylogenetic approaches but lack of chronological references makes dating the exact onset of tumours very challenging. Patients and methods Here, we describe the case of a colorectal cancer (CRC) patient presenting with synchronous lung metastasis and metachronous thyroid, chest wall and urinary tract metastases over the course of 5 years. The chest wall metastasis was caused by needle tract seeding, implying a known time of onset. Using whole genome sequencing data from primary and metastatic sites we inferred the complete chronology of the cancer by exploiting the time of needle tract seeding as an in vivo ‘stopwatch’. This approach allowed us to follow the progression of the disease back in time, dating each ancestral node of the phylogenetic tree in the past history of the tumour. We used a Bayesian phylogenomic approach, which accounts for possible dynamic changes in mutational rate, to reconstruct the phylogenetic tree and effectively ‘carbon date’ the malignant progression. Results The primary colon cancer emerged between 5 and 8 years before the clinical diagnosis. The primary tumour metastasized to the lung and the thyroid within a year from its onset. The thyroid lesion presented as a tumour-to-tumour deposit within a benign Hurthle adenoma. Despite rapid metastatic progression from the primary tumour, the patient showed an indolent disease course. Primary cancer and metastases were microsatellite stable and displayed low chromosomal instability. Neo-antigen analysis suggested minimal immunogenicity. Conclusion Our data provide the first in vivo experimental evidence documenting the timing of metastatic progression in CRC and suggest that genomic instability might be more important than the metastatic potential of the primary cancer in dictating CRC fate.

KRAS and BRAF mutations in circulating tumour DNA from locally advanced rectal cancer

There are limited data on circulating, cell-free, tumour (ct)DNA analysis in locally advanced rectal cancer (LARC). Digital droplet (dd)PCR was used to investigate KRAS/BRAF mutations in ctDNA from baseline blood samples of 97 LARC patients who were treated with CAPOX followed by chemoradiotherapy, surgery and adjuvant CAPOX ± cetuximab in a randomised phase II trial. KRAS mutation in G12D, G12V or G13D was detected in the ctDNA of 43% and 35% of patients with tumours that were mutant and wild-type for these hotspot mutations, respectively, according to standard PCR-based analyses on tissue. The detection rate in the ctDNA of 10 patients with less common mutations was 50%. In 26 cases ctDNA analysis revealed KRAS mutations that were not previously found in tissue. Twenty-two of these (84.6%) were detected following repeat tissue testing by ddPCR. Overall, the ctDNA detection rate in the KRAS mutant population was 66%. Detection of KRAS mutation in ctDNA failed to predict prognosis or refine patient selection for cetuximab. While this study confirms the feasibility of ctDNA analysis in LARC and the high sensitivity of ddPCR, larger series are needed to better address the role of ctDNA as a prognostic or predictive tool in this setting.

Longitudinal Liquid Biopsy and Mathematical Modeling of Clonal Evolution Forecast Time to Treatment Failure in the PROSPECT-C Phase II Colorectal Cancer Clinical Trial

Sequential profiling of plasma cell-free DNA (cfDNA) holds immense promise for early detection of patient progression. However, how to exploit the predictive power of cfDNA as a liquid biopsy in the clinic remains unclear. RAS pathway aberrations can be tracked in cfDNA to monitor resistance to anti-EGFR monoclonal antibodies in patients with metastatic colorectal cancer. In this prospective phase II clinical trial of single-agent cetuximab in RAS wild-type patients, we combine genomic profiling of serial cfDNA and matched sequential tissue biopsies with imaging and mathematical modeling of cancer evolution. We show that a significant proportion of patients defined as RAS wild-type based on diagnostic tissue analysis harbor aberrations in the RAS pathway in pretreatment cfDNA and, in fact, do not benefit from EGFR inhibition. We demonstrate that primary and acquired resistance to cetuximab are often of polyclonal nature, and these dynamics can be observed in tissue and plasma. Furthermore, evolutionary modeling combined with frequent serial sampling of cfDNA allows prediction of the expected time to treatment failure in individual patients. This study demonstrates how integrating frequently sampled longitudinal liquid biopsies with a mathematical framework of tumor evolution allows individualized quantitative forecasting of progression, providing novel opportunities for adaptive personalized therapies.Significance: Liquid biopsies capture spatial and temporal heterogeneity underpinning resistance to anti-EGFR monoclonal antibodies in colorectal cancer. Dense serial sampling is needed to predict the time to treatment failure and generate a window of opportunity for intervention. Cancer Discov; 8(10); 1270-85. ©2018 AACR. See related commentary by Siravegna and Corcoran, p. 1213 This article is highlighted in the In This Issue feature, p. 1195.

Sequence variation in mature microRNA-608 and benefit from neo-adjuvant treatment in locally advanced rectal cancer patients

Summary Analysis of a polymorphism in mature microRNA-608 (rs4919510) in rectal cancer patients enrolled in a randomized phase II clinical trial identified patient subpopulations who might benefit from the use of an intensified neo-adjuvant treatment strategy with Cetuximab.