Generation of Metastatic Cholangiocarcinoma Patient-Derived Xenograft Models

Cholangiocarcinoma (CCA) poses a substantial clinical hurdle as it is often detected at advanced metastatic stages with limited therapeutic options. To enhance our understanding of advanced CCA, it is imperative to establish preclinical models that faithfully recapitulate the disease's characteristics. Patient-derived xenograft (PDX) models have emerged as a valuable approach in cancer research, offering an avenue to reproduce and study the genomic, histologic, and molecular features of the original human tumors. By faithfully preserving the heterogeneity, microenvironmental interactions, and drug responses observed in human tumors, PDX models serve as highly relevant and predictive preclinical tools. Here, we present a comprehensive protocol that outlines the step-by-step process of generating and maintaining PDX models using biopsy samples from patients with advanced metastatic CCA. The protocol encompasses crucial aspects such as tissue processing, xenograft transplantation, and subsequent monitoring of the PDX models. By employing this protocol, we aim to establish a robust collection of PDX models that accurately reflect the genomic landscape, histologic diversity, and therapeutic responses observed in advanced CCA, thereby enabling improved translational research, drug development, and personalized treatment strategies for patients facing this challenging disease.

Clinical and genomic characterisation of early-onset pancreatic cancer

BACKGROUND

The incidence of early-onset pancreatic cancer (EOPC) has risen dramatically in recent years. We aimed to characterise the clinical and genomic features of EOPC and evaluate their therapeutic implications.

METHODS

We performed a comparative, single-centre, retrospective analysis of clinical, germline, and genomic features in EOPC (≤50 years) patients and compared them with a control group of average-onset pancreatic cancer patients (AOPC, ≥70 years). Key molecular findings were compared with an external, publicly available cohort.

RESULTS

We reviewed 336 patients who met all inclusion criteria (EOPC N = 139, AOPC N = 197). EOPC was associated with smoking status, lower prevalence of diabetes, better performance status, higher CA19.9 levels, and higher albumin levels at diagnosis. After adjustment for baseline covariates, we observed no differences in overall survival (OS). Age was associated with an increase in the incidence of KRASMUT both in our cohort and the validation cohort. EOPC were enriched in potentially actionable alterations according to ESCAT tiers I-IIIA when compared with AOPC in discovery and validation cohorts (19% versus 14% and 14% versus 8%, respectively). In the first-line metastatic setting, EOPC had a longer progression-free survival (hazard ratio [HR] 0.61, 95% confidence interval (CI) 0.43-0.87) and OS (HR 0.65, 95% CI 0.45-0.95), although there were no differences in response rate. After adjusting for the number of treatment lines, EOPC patients who did receive targeted therapies exhibited longer OS compared with EOPC who did not (HR 0.34, 95% CI 0.12-0.93).

CONCLUSIONS

EOPC patients have improved outcomes in the metastatic setting when compared to AOPC and are enriched for targetable alterations that open opportunities for precision oncology-based approaches.

Liquid biopsy after resection of pancreatic adenocarcinoma and its relation to oncological outcomes. Systematic review and meta-analysis

BACKGROUND

It has been hypothesised that manipulation during surgery releases tumoral components into circulation. We investigate the effect of surgery on plasma-borne DNA biomarkers and the oncological outcomes in resectable pancreatic ductal adenocarcinoma (PDAC). We also compare non-touch isolation techniques (NTIT) with standard techniques.

MATERIALS AND METHODS

We performed a systematic review and a meta-analysis of studies analysing liquid biopsy as circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), and messenger RNA (mRNA) in resectable PDAC patients who underwent surgery and its association with overall survival (OS) and disease-free survival (DFS). Research in EMBASE, Web of Science and PubMed was performed. The ctDNA shift negative-to-positive (ctDNA -/+) or ctDNA shift positive-to-negative (ctDNA +/-) before and after surgery was evaluated.

RESULTS

Twelve studies comprising 413 patients were included. Shorter OS and DFS were identified in patients with positive ctDNA status before (HR = 2.28, p = 0.005 and HR = 2.16, p = 0.006) or after surgery (HR = 3.88, p < 0.0001 and HR = 3.81, p = 0.03), respectively. Surgical resection increased the rate of ctDNA +/-. There were no differences in OS or DFS in the ctDNA +/- group compared with ctDNA +/+ or ctDNA -/+. However, there was a trend to shorter OS in the ctDNA -/+ group (HR = 5.00, p = 0.09). No differences between NTIT and standard techniques on liquid biopsy status were found.

CONCLUSION

Positive ctDNA in the perioperative period is associated with a worse prognosis. Surgical resection has a role in the negativisation of liquid biopsy status. More studies are needed to assess the potential of minimally invasive techniques on ctDNA dynamics.

Human Metastatic Cholangiocarcinoma Patient-Derived Xenografts and Tumoroids for Preclinical Drug Evaluation

PURPOSE

Cholangiocarcinoma (CCA) is usually diagnosed at advanced stages, with limited therapeutic options. Preclinical models focused on unresectable metastatic CCA are necessary to develop rational treatments. Pathogenic mutations in IDH1/2, ARID1A/B, BAP1, and BRCA1/2 have been identified in 30%-50% of patients with CCA. Several types of tumor cells harboring these mutations exhibit homologous recombination deficiency (HRD) phenotype with enhanced sensitivity to PARP inhibitors (PARPi). However, PARPi treatment has not yet been tested for effectiveness in patient-derived models of advanced CCA.

EXPERIMENTAL DESIGN

We have established a collection of patient-derived xenografts from patients with unresectable metastatic CCA (CCA_PDX). The CCA_PDXs were characterized at both histopathologic and genomic levels. We optimized a protocol to generate CCA tumoroids from CCA_PDXs. We tested the effects of PARPis in both CCA tumoroids and CCA_PDXs. Finally, we used the RAD51 assay to evaluate the HRD status of CCA tissues.

RESULTS

This collection of CCA_PDXs recapitulates the histopathologic and molecular features of their original tumors. PARPi treatments inhibited the growth of CCA tumoroids and CCA_PDXs with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1. In line with these findings, only CCA_PDX and CCA patient biopsy samples with mutations of BRCA2 showed RAD51 scores compatible with HRD.

CONCLUSIONS

Our results suggest that patients with advanced CCA with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1, are likely to benefit from PARPi therapy. This collection of CCA_PDXs provides new opportunities for evaluating drug response and prioritizing clinical trials.

Clinical Outcomes After Progression on First-Line Therapies in IDH1 Mutated Versus Wild-Type Intrahepatic Cholangiocarcinoma Patients

BACKGROUND

Isocitrate dehydrogenase-1 (IDH1) mutations occur in a significant proportion of intrahepatic cholangiocarcinomas (iCCAs). No data are available regarding the prognostic impact of IDH1 mutations in advanced iCCA patients after progression on first-line therapies.

OBJECTIVE

We investigated the role of IDH1 mutation in advanced iCCA after progression on first-line therapies.

PATIENTS AND METHODS

After progression on first-line therapies for advanced iCCA, consecutive patients were retrospectively collected. The IDH1 status was tested at baseline. This analysis aimed to examine the association between the presence of IDH1 missense mutations and survival outcomes in patients with advanced iCCA treated with a second-line therapy.

RESULTS

The analysis included 119 patients; 56/119 (47%) were IDH1 mutated (IDH1m) and 63/119 (53%) were IDH1 wild type (IDH1 WT). At univariate analysis for overall survival (OS), the presence of IDH1 mutation was associated with a worse median OS (mOS; 8.2 vs. 14.1 months; hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.2-3.0, p = 0.0047). Patients harboring IDH1 mutations showed a worse objective response rate (ORR) compared with patients without IDH1 mutation, whereas no significant differences in disease control rate (DCR) were found. Multivariate analysis confirmed IDH1 mutations as an independent negative prognostic factor for OS (HR 1.7, 95% CI 1.1-2.7, p = 0.0256). By evaluating only patients receiving FOLFOX as second-line therapy, no statistically significant differences were found in terms of both OS and PFS between IDH1m and IDH1 WT patients. In this subset of patients, those harboring an IDH1 mutation showed a worse ORR and DCR compared with those without. Finally, at univariate analysis for OS from third-line treatment, the presence of an IDH1 mutation was associated with a trend toward a worse mOS (6.0 vs. 11.9 months; HR 1.6, 95% CI 0.8-3.2, p = 0.25).

CONCLUSION

The present analysis constitutes the first evidence of a negative prognostic impact of IDH1 mutations in a cohort of patients treated after progression on first-line therapies in contrast to IDH1 inhibitors.

Molecular profile and its clinical impact of IDH1 mutated versus IDH1 wild type intrahepatic cholangiocarcinoma

IDH1-mutated cholangiocarcinomas (CCAs) are an interesting group of neoplasia with particular behavior and therapeutic implications. The aim of the present work is to highlight the differences characterizing IDH1m and IDH1wt CCAs in terms of genomic landscape. 284 patients with iCCA treated for resectable, locally advanced or metastatic disease were selected and studied with the FOUNDATION Cdx technology. A comparative genomic analysis and survival analyses for the most relevant altered genes were performed between IDH1m and IDH1wt patients. Overall, 125 patients were IDH1m and 122 IDH1wt. IDH1m patients showed higher mutation rates compared to IDH1wt in CDKN2B and lower mutation rates in several genes including TP53, FGFR2, BRCA2, ATM, MAP3K1, NOTCH2, ZNF703, CCND1, NBN, NF1, MAP3KI3, and RAD21. At the survival analysis, IDH1m and IDH1wt patients showed no statistically differences in terms of survival outcomes, but a trend in favor of IDH1wt patients was observed. Differences in prognostic values of the most common altered genes were reported. In surgical setting, in IDH1m group the presence of CDKN2A and CDKN2B mutations negatively impact DFS, whereas the presence of CDKN2A, CDKN2B, and PBRM1 mutations negatively impact OS. In advanced setting, in the IDH1m group, the presence of KRAS/NRAS and TP53 mutations negatively impact PFS, whereas the presence of TP53 and PIK3CA mutations negatively impact OS; in the IDH1wt group, only the presence of MTAP mutation negatively impact PFS, whereas the presence of TP53 mutation negatively impact OS. We highlighted several molecular differences with distinct prognostic implications between IDH1m and IDH1wt patients.

Advances in the systemic treatment of therapeutic approaches in biliary tract cancer

INTRODUCTION

Biliary tract cancers (BTCs) are a rare and heterogenous group with an increasing incidence and high mortality rate. The estimated new cases and deaths of BTC worldwide are increasing, but the incidence and mortality rates in South East Asia are the highest worldwide, representing a real public health problem in these regions. BTC has a poor prognosis with a median overall survival <12 months. Thus, an urgent unmet clinical need for BTC patients exists and must be addressed.

RESULTS

The backbone treatment of these malignancies is chemotherapy in first- and second-line setting, but in the last decade a rich molecular landscape has been discovered, expanding conceivable treatment options. Some druggable molecular aberrations can be treated with new targeted therapies and have already demonstrated efficacy in patients with BTC, improving clinical outcomes, such as the FGFR2 or IDH1 inhibitors. Many other molecular alterations are being discovered and the treatment of BTC will change in the near future from our current clinical practice.

CONCLUSIONS

In this review we discuss the epidemiology, molecular characteristics, present treatment approaches, review the recent therapeutic advances, and explore future directions for patients with BTC. Due to the rich molecular landscape of BTC, molecular profiling should be carried out early. Ongoing research will bring new targeted treatments and immunotherapy in the near future.

FGFR2 fusion detection in plasma: A new era in the clinical monitoring of iCCA

4085

Background: Actionable genetic alterations can be identified in over 50% of intrahepatic cholangiocarcinoma (iCCA). Since EMA approved Pemigatinib, a selective Fibroblast growth factor receptor 1-3 (FGFR1-3) inhibitor for the treatment of CCA with FGFR2 fusions or rearrangements, the screening of patients who may benefit from such targeted therapies is especially relevant. In addition, novel FGFR inhibitors that are effective for treatment of resistant mutant clones are under development. In patients with no available tissue for genomic profiling or at different timepoints after targeted therapy, NGS testing of circulating cell-free DNA (ccfDNA) would be the most convenient option. Hence, two important issues must be addressed: i) technical set-up and validation of detection of FGFR2 rearrangements in plasma, and ii) patient shedding in iCCA, in order to consider liquid biopsy for routine clinical care. Methods: We conducted a retrospective study in a cohort of 18 iCCA patients with known FGFR2 fusion or rearrangement events previously identified in tumor FFPE by NGS (FoundationOne CDx test). A custom-designed capture-based NGS panel for use in plasma or tissue (VHIO-iCCA test) was developed to detect FGFR2 rearrangements and other common altered genes in iCCA. After validating our VHIO-iCCA panel with fusion positive FFPE samples, a concordance study was conducted to evaluate the detection of FGFR2 fusion and rearrangements in matched-to-tissue timepoint plasmas. Finally, additional serial plasma samples taken during FGFR inhibitor treatment were also analyzed. Results: From the 18 rearrangement events previously detected with FoundationOne CDx, we were able to identify all 18 in FFPE samples and 15 in the paired plasma using our VHIO-iCCA panel, representing a 100% and 83% concordance, respectively. In the 3 discordant cases, no additional alterations were detected in plasma, indicating a lack of circulating tumor DNA (ctDNA) shedding. Serial sampling of these patients indicated persistent non-shedding. The analysis of fusion allele fraction (FAF) in serial plasma samples revealed that detection of fusion FGFR2 changed during treatment and correlated with best response. In general, patients with a stable FAF showed a SD, while patients which reduced FAF presented a PR. Conclusions: This extremely valuable set of cases has allowed us to validate our VHIO-iCCA panel to be used in tissue and plasma, and to determine that the sensitivity in plasma is >80%, making this a feasible option to avoid tissue biopsies, whenever patients cannot undergo the procedure and even to aid in cancer monitoring. Patient shedding is high in iCCA, yet a fraction of patients may not find a useful resource in liquid biopsy. For those who shed ctDNA, monitoring through the FAF may guide clinical management of iCCA.

KRAS mutation detection and cfDNA in liquid biopsy as prognostic factors in pancreatic adenocarcinoma

e16302

Background: Approximately 80% of pancreatic ductal adenocarcinoma (PDAC) patients present with advanced disease at diagnosis, with a 5-year survival rate of less than 5%. According to molecular profiling, mutations in KRAS have been described in 90% of PDAC patients, and correlated with poor prognosis. Nevertheless, the invasiveness of tumor biopsy and the difficulties in obtaining quality samples in some patients remains a concern. Circulating free DNA (cfDNA) is considered a surrogate marker of tumor burden and may also act as a prognostic factor that can be used independently from tumor biopsy. In this study, we aim to explore molecular prognostic biomarkers using plasma samples. Methods: Patients with metastatic PDAC harboring KRAS mutation in tissue samples and treated with first-line chemotherapy were identified at Vall d’Hebron University Hospital. Clinical features and plasma samples were collected before starting any treatment. DNA mutations were analyzed in plasma and compared with tissue samples. In plasma, detection of KRAS mutation and total cfDNA concentration were evaluated for clinical significance. A cfDNA minimum 100 genome equivalent threshold was proposed based on results and utility. A Chi-square test was planned to prove the independence between cfDNA levels and KRAS detection in plasma. Survival analysis was performed using the Kaplan-Meier method. Results: We included 33 PDAC patients with a median age of 66.1 years old, 57% were women. All of them were treated with gemcitabine and Nab-paclitaxel. At the final analysis cut-off, 31 patients had died . KRAS mutation was detected in 25 patients’ blood samples (75.8%) and cfDNA-High levels were considered for 20 patients (60.6%). 19 of 20 (95%) patients with cfDNA-High correlated with KRAS blood detection, showing significant dependence (p-value 0.001). Median overall survival (OS) was 10.5 months in the KRAS detected group compared with 22.6 months in the KRAS non-detected group (HR for death 4.70; confidence interval (CI) 1.70-12.98, p-value 0.002). Better separation was seen using cfDNA where median OS was 9.8 months in the cfDNA-High group compared with 21.0 months in the cfDNA-Low group (HR for death 5.38; CI 2.17-13.31, p-value < 0.001). Conclusions: Liquid biopsy can provide quality prognostic information in metastatic PDAC patients. On account of this, the cfDNA level is proposed as a prognostic factor. However, prospective cohorts to validate this information are needed.[Table: see text]

Long-term results of the GEINO 1401 TRIAL: Randomizing patients to stop or to continue temozolomide until 12 cycles

2013

Background: We previously presented our results of the GEINO 1401 trial that randomized patients diagnosed with glioblastoma and treated with chemoradiotherapy and adjuvant temozolomide (TMZ) followed by six cycles of TMZ, to receive an extended use of TMZ up to 12 cycles or to control. We found no differences in 6-months neither progression free survival (PFS) nor overall survival (OS). In this report we actualize our results and analyse long-term survivor patients (LTSP). Methods: The trial NCT02209948 randomized (ratio 1:1) 159 patients diagnosed with glioblastoma who had been treated with standard therapy to stop treatment or to continue up to 12 cycles of TMZ. Patients were stratified based on their O6-methylguanine-DNA-methyltransferasa (MGMT) methylation status and presence or absence of measurable disease at inclusion. We update here OS outcomes and analyse the data of LTSP defined as an OS over 30 months from diagnosis. Results: At a median follow-up of 20 months, 82.4% of the patients had died and 89.9% had progressed. The median OS from randomization was 22.0 months for the control arm and 18.2 for the experimental arm: HR 0.957 (95%CI 0.806-1.136, p = 0.615). At 2 years from randomization there were a 61% of survivors in the TMZ group and 62% in the control group. There were a 49.7% of LTSP showing no differences between TMZ and control group. We found a higher prevalence of methylated MGMT in LTSP, but no differences were shown in patients with or without measurable disease at inclusion, status of IDH and the use of bevacizumab after progression. Conclusions: Adding 6 cycles of TMZ after the first 6 adjuvant cycles confers no additional benefit in OS. Nearly 50% of the patients included in GEINO 1401 who had been previously treated with TMZ 6 cycles without progressing were LTSP. Clinical trial information: NCT02209948.