Why Is Wnt/ß-Catenin Not Yet Targeted in Routine Cancer Care?

Despite significant progress in cancer prevention, screening, and treatment, the still limited number of therapeutic options is an obstacle towards increasing the cancer cure rate. In recent years, many efforts were put forth to develop therapeutics that selectively target different components of the oncogenic Wnt/ß-catenin signaling pathway. These include small molecule inhibitors, antibodies, and more recently, gene-based approaches. Although some of them showed promising outcomes in clinical trials, the Wnt/ß-catenin pathway is still not targeted in routine clinical practice for cancer management. As for most anticancer treatments, a critical limitation to the use of Wnt/ß-catenin inhibitors is their therapeutic index, i.e., the difficulty of combining effective anticancer activity with acceptable toxicity. Protecting healthy tissues from the effects of Wnt/ß-catenin inhibitors is a major issue due to the vital role of the Wnt/ß-catenin signaling pathway in adult tissue homeostasis and regeneration. In this review, we provide an up-to-date summary of clinical trials on Wnt/ß-catenin pathway inhibitors, examine their anti-tumor activity and associated adverse events, and explore strategies under development to improve the benefit/risk profile of this therapeutic approach.

Regorafenib plus FOLFIRINOX as first-line treatment for patients with RAS-mutant metastatic colorectal cancer (FOLFIRINOX-R trial): a dose-escalation study.

PURPOSE: The combination of bevacizumab and FOLFIRINOX is used in patients with RAS-mutant metastatic colorectal cancer (RASm-mCRC). Regorafenib, an oral multi-tyrosine kinase inhibitor, has antiangiogenic properties, cytostatic effects and also true cytotoxic effects, unlike bevacizumab. The aim of this study was to determine the maximum tolerated dose (MTD) and the recommended phase 2 dose (RP2D) of the regorafenib-FOLFIRINOX combination in patients with RASm-mCRC. METHODS: The FOLFIRINOX-R trial was a phase 1/2 study where the dose-escalation part (3 + 3 design with three dose levels, DLs) was completed before its early termination. FOLFIRINOX (14-day cycle) included oxaliplatin (standard dose), folinic acid, fluorouracil and irinotecan (150 or 180 mg/m²). Regorafenib (120 or 160 mg daily) was given from day 4 to day 10 of each cycle. Dose-limiting toxicity (DLT) was studied in the first three cycles. Eligibility criteria included ECOG performance status ≤ 1 and not previously treated RASm-mCRC. RESULTS: Thirteen patients (median age: 65 years; min-max: 40-76) were enrolled. DLT could not be evaluated in one patient (DL3) due to poor observance. The median treatment duration and median follow-up were 6.2 (min-max: 2.3-10) and 13.4 (min-max: 3.8-18.0) months, respectively. Dose was modified in 12/13 (92%) patients. One grade 3 hypokalemia occurred at DL2. MTD was not reached at DL3. Grade 3 diarrhea was recorded in 7/13 patients (13 events) equally distributed in all DLs. CONCLUSION: The RP2D for this regorafenib-FFX combination could not be determined due to a high prevalence of grade 3 diarrhea related to treatment as advised by our Independent Data Monitoring Committee. TRIAL REGISTRATION NUMBERS: ClinicalTrials.gov : NCT03828799.

Neoadjuvant radiotherapy combined with fluorouracil-cisplatin plus cetuximab in operable, locally advanced esophageal carcinoma: Results of a phase I-II trial (FFCD-0505/PRODIGE-3).

Background: Radiotherapy combined with fluorouracil (5FU) and cisplatin for locally advanced esophageal cancer is associated with a 20-25% pathologic complete response (pCR) rate. Cetuximab increases the efficacy of radiotherapy in patients with head and neck carcinomas. The aim of this phase I/II trial was to determine the optimal doses and the pCR rate with chemoradiotherapy (C-RT) plus cetuximab. Methods: A 45-Gy radiotherapy regimen was delivered over 5 weeks. The phase I study determined the dose-limiting toxicity and the maximum tolerated dose of 5FU-cisplatin plus cetuximab. The phase II trial aimed to exhibit a pCR rate > 20 % (25 % expected), requiring 33 patients (6 from phase I part plus 27 in phase II part). pCR was defined as ypT0Nx. Results: The phase I study established the following recommended doses: weekly cetuximab (400 mg/m2 one week before, and 250 mg/m2 during radiotherapy); 5FU (500 mg/m2/day, d1-d4) plus cisplatin (40 mg/m2, d1) during week 1 and 5. In the phase II part, 32 patients received C-RT before surgery, 31 patients underwent surgery, and resection was achieved in 27 patients. A pCR was achieved in five patients (18.5 %) out of 27. After a median follow-up of 19 months, the median progression-free survival was 13.7 months, and the median overall survival was not reached. Conclusions: Adding cetuximab to preoperative C-RT was toxic and did not achieve a pCR > 20 % as required. The recommended doses, determined during the phase I part, could explain these disappointing results due to a reduction in chemotherapy dose-intensity. Trial registration: This trial was registered with EudraCT number 2006-004770-27.

Prognostic value of the tumor-to-liver density ratio in patients with metastatic colorectal cancer treated with bevacizumab-based chemotherapy. A post-hoc study of the STIC-AVASTIN trial.

BACKGROUND: The Response Evaluation Criteria in Solid Tumors (RECIST) are often inadequate for the early assessment of the response to cancer therapy, particularly bevacizumab-based chemotherapy. In a first cohort of patients with colorectal cancer liver metastases (CRLM), we showed that variations of the tumor-to-liver density (TTLD) ratio and modified size-based criteria determined using computed tomography (CT) data at the first restaging were better prognostic criteria than the RECIST. The aims of this study were to confirm the relevance of these radiological biomarkers as early predictors of the long-term clinical outcome and to assess their correlation with contrast-enhanced ultrasound (CEUS) parameters in a new patient cohort. METHODS: In this post-hoc study of the multicenter STIC-AVASTIN trial, we retrospectively reviewed CT data of patients with CRLM treated with bevacizumab-based regimens. We determined the size, density and TTLD ratio of target liver lesions at baseline and at the first restaging and also performed a morphologic evaluation according to the MD Anderson criteria. We assessed the correlation of these parameters with progression-free survival (PFS) and overall survival (OS) using the log-rank test and a Cox proportional hazard model. We also examined the association between TTLD ratio and quantitative CEUS parameters. RESULTS: This analysis concerned 79 of the 137 patients included in the STIC-AVASTIN trial. PFS and OS were significantly longer in patients with tumor size reduction > 15% at first restaging, but were not correlated with TTLD ratio variations. However, PFS was longer in patients with TTLD ratio > 0.6 at baseline and first restaging than in those who did not reach this threshold. In the multivariate analysis, only baseline TTLD ratio > 0.6 was a significant survival predictor. TTLD ratio > 0.6 was associated with improved perfusion parameters. CONCLUSIONS: Although TTLD ratio variations did not correlate with the long-term clinical outcomes, TTLD absolute values remained a good predictor of survival at baseline and first restaging, and may reflect tumor microvascular features that might influence bevacizumab-based treatment efficiency. TRIAL REGISTRATION: NCT00489697, registration number of the STIC-AVASTIN trial.

Motor disorders related to oxaliplatin-induced peripheral neuropathy: long-term severity and impact on quality of life.

PURPOSE: Sensory chemotherapy-induced peripheral neuropathy (CIPN) is well-recognized, but motor CIPN remains understudied. This secondary analysis focused on the long-term severity and impact of motor disorders, their relation to sensory CIPN, neuropathic pain, psychological distress, and health-related quality of life (HRQoL) after oxaliplatin-based chemotherapy in colorectal cancer (CRC) survivors. METHODS: Data from a multicenter, cross-sectional study were re-analyzed to explore motor CIPN among CRC survivors up to 5 years post-chemotherapy, with no longitudinal follow-up. Questionnaires assessed sensory and motor CIPN (QLQ-CIPN20), neuropathic pain (DN4), anxiety and depression (HADS), and HRQoL (QLQ-C30). RESULTS: Among 405 CRC survivors, 31.1% had sensory CIPN as previously described. When categorizing the 405 CRC survivors based on the years since their last oxaliplatin-based chemotherapy, the motor scores derived from the QLQ-CIPN20 showed no significant difference between years (p = 0.08). Motor CIPN scores correlated with female gender, higher oxaliplatin dose intensity, sensory CIPN, and neuropathic pain. Motor CIPN also linked to decreased HRQoL and increased psychological distress. CONCLUSION: The study underscores the detrimental impact of motor disorders on CRC survivors post-oxaliplatin-based chemotherapy. Oncologists should prioritize assessing and managing motor manifestations alongside sensory symptoms to enhance post-cancer quality of life. TRIAL REGISTRATION: NCT02970526 (2016-11-22). https://classic. CLINICALTRIALS: gov/ct2/show/NCT02970526?term=NCT02970526&draw=2&rank=1 .

A multicenter study evaluating efficacy of immune checkpoint inhibitors in advanced non-colorectal digestive cancers with microsatellite instability.

BACKGROUND: One randomized phase III trial comparing chemotherapy (CT) with immune checkpoint inhibitors (ICI) has demonstrated significant efficacy of ICI in deficient DNA mismatch repair system/microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer. However, few studies have compared ICI with CT in other advanced dMMR/MSI-H digestive tumors. METHODS: In this multicenter study, we included patients with advanced dMMR/MSI-H non-colorectal digestive tumors treated with chemotherapy and/or ICIs. Patients were divided retrospectively into two groups, a CT group and an immunotherapy (IO) group. The primary endpoint was progression-free survival (PFS). A propensity score approach using the inverse probability of treatment weighting (IPTW) method was applied to deal with potential differences between the two groups. RESULTS: 133 patients (45.1/27.1/27.8% with gastric/small bowel/other carcinomas) were included. The majority of patients received ICI in 1st (29.1%) or 2nd line (44.4%). The 24-month PFS rates were 7.9% in the CT group and 71.2% in the IO group. Using the IPTW method, IO treatment was associated with better PFS (HR=0.227; 95% CI 0.147-0.351; p < 0.0001). The overall response rate was 26.3% in the CT group versus 60.7% in the IO group (p < 0.001) with prolonged duration of disease control in the IO group (p < 0.001). In multivariable analysis, predictive factors of PFS for patients treated with IO were good performance status, absence of liver metastasis and prior primary tumor resection, whereas no association was found for the site of the primary tumor. CONCLUSIONS: In the absence of randomized trials, our study highlights the superior efficacy of ICI compared with standard-of-care therapy in patients with unresectable or metastatic dMMR/MSI-H non-colorectal digestive cancer, regardless of tumor type, with acceptable toxicity.

Triplet chemotherapy plus cetuximab as first-line treatment in extended RAS wild-type metastatic colorectal cancer patients.

BACKGROUND: Triplet chemotherapy plus cetuximab showed promising results in phase II trials in unsystematically selected RAS population. We evaluated FOLFIRINOX+cetuximab efficacy as first-line treatment in extended RAS wild-type metastatic colorectal cancer (mCRC) patients. METHODS: We retrospectively analyzed patients treated with FOLFIRINOX+cetuximab, using data from clinical trials and real-life practice. Extended mutation analysis was performed when RAS/BRAF status was unavailable. The primary endpoint was progression-free survival (PFS). RESULTS: Seventy patients (61.4 % male, median age 58.7 years) were analyzed. Eighty percent had left-sided mCRC and 97.1 % had liver metastases. Median PFS and overall survival (OS) were 13.3 and 48.5 months, respectively. The objective response rate was 85.7 %, with 20 % complete response. Primary tumor location did not affect OS and PFS. BRAF wild-type patients (n = 65) had longer PFS (13.3 vs. 6.0 months; p = 0.005) and OS (50.1 vs. 21.2 months; p = 0.007) than BRAF mutated patients (n = 5, including four BRAFV600E). Median OS was significantly longer in resected patients (n = 39, 55.1 vs. 30.7 months; p = 0.030). Main toxicities were diarrhea (31.4 %) and neutropenia (21.4 %). CONCLUSION: FOLFIRINOX+cetuximab provides good PFS, high response rate and prolonged disease control in initially unresectable extended RAS wild-type mCRC. This combination is particularly interesting for selected patients with liver-limited disease eligible to secondary resection.

Primary resistance to immunotherapy in patients with a dMMR/MSI metastatic gastrointestinal cancer: who is at risk? An AGEO real-world study.

BACKGROUND: The outstanding efficacy of immunotherapy in metastatic dMMR/MSI gastro-intestinal (GI) cancers has led to a rapid increase in the number of patients treated. However, 20-30% of patients experience primary resistance to immune checkpoint inhibitors (ICIPR) and need better characterization. METHODS: This AGEO real-world study retrospectively analyzed the efficacy and safety of ICIs and identified clinical variables associated with ICIPR in patients with metastatic dMMR/MSI GI cancers treated with immunotherapy between 2015 and 2022. RESULTS: 399 patients were included, 284 with colorectal cancer (CRC) and 115 with non-CRC, mostly treated by an anti-PD(L)1 (88.0%). PFS at 24 months was 55.8% (95CI [50.8-61.2]) and OS at 48 months was 59.1% (95CI [53.0-65.9]). ORR was 51.0%, and 25.1% of patients were ICIPR. There was no statistical difference in ORR, DCR, PFS, or OS between CRC and non-CRC groups. In multivariable analysis, ICIPR was associated with ECOG-PS ≥ 2 (OR = 3.36), liver metastases (OR = 2.19), peritoneal metastases (OR = 2.00), ≥1 previous line of treatment (OR = 1.83), and age≤50 years old (OR = 1.76). CONCLUSION: These five clinical factors associated with primary resistance to ICIs should be considered by physicians to guide treatment choice in GI dMMR/MSI metastatic cancer patients.

GRECCAR 14 - a multicentric, randomized, phase II-III study evaluating the tailored management of locally advanced rectal carcinoma after a favourable response to induction chemotherapy: Study protocol.

AIM: Total neoadjuvant treatment (TNT) is becoming standard in patients with locally advanced rectal carcinoma (LARC). Preoperative chemoradiotherapy (CRT) has proven side effects on bowel and genitourinary function. An early tumoral response to induction chemotherapy demonstrates its high prognostic value. Tailored management could be used as an alternative to systematic CRT. The GRECCAR 14 trial will attempt to personalize treatment strategy according to the patient's early tumour response to intensive chemotherapy with the aim of achieving the best toxicity-efficiency ratio. METHOD: GRECCAR 14 is a multicentric, randomized, two-arm, phase II-III noninferiority trial. Patients with mid or low LARC with a predictive circumferential resection margin ≤2 mm or T3c-d stage with extramural venous invasion will be included. Evaluation of the tumoral response will be performed after six courses of high-dose FOLFIRINOX chemotherapy. Good responders (GRs) will be defined by a 60% decrease in tumoral volume on magnetic resonance imaging. Patients will be randomized to CRT before surgery. The primary endpoints will be R0 resection for phase II and the 3-year disease-free survival (DFS) for phase III. RESULTS: Tailored management of LARC is becoming an exciting challenge for the modality of neoadjuvant treatment and for the type of surgery or its omission. Neoadjuvant FOLFIRINOX has established efficacy, with a significant increase in the 3-year DFS. Better control of systemic disease must be accompanied by the same locoregional control, with the lowest morbidity. Our previous GRECCAR 4 trial demonstrated the high value of the early tumoral response after induction chemotherapy and the long-term safety of tailored management for GRs. CONCLUSION: If GRECCAR 14 demonstrates the ability to tailor TNT for LARC, this could lead to changes in clinical practice.

Comparison of the structures and topologies of plasma extracted circulating nuclear and mitochondrial cell-free DNA.

Introduction: The function, origin and structural features of circulating nuclear DNA (cir-nDNA) and mitochondrial DNA (cir-mtDNA) are poorly known, even though they have been investigated in numerous clinical studies, and are involved in a number of routine clinical applications. Based on our previous report disproving the conventional plasma isolation used for cirDNA analysis, this work enables a direct topological comparison of the circulating structures associated with nuclear DNA and mitochondrial cell-free DNA. Materials and methods: We used a Q-PCR and low-pass whole genome sequencing (LP-WGS) combination approach of cir-nDNA and cir-mtDNA, extracted using a procedure that eliminates platelet activation during the plasma isolation process to prevent mitochondria release in the extracellular milieu. Various physical procedures, such as filtration and differential centrifugation, were employed to infer their circulating structures. Results: DSP-S cir-mtDNA mean size profiles distributed on a slightly shorter range than SSP-S. SSP-S detected 40-fold more low-sized cir-mtDNA fragments (<90 bp/nt) and three-fold less long-sized fragments (>200 bp/nt) than DSP-S. The ratio of the fragment number below 90 bp over the fragment number above 200 bp was very homogenous among both DSP-S and SSP-S profiles, being 134-fold lower with DSP-S than with SSP-S. Cir-mtDNA and cir-nDNA DSP-S and SSP-S mean size profiles of healthy individuals ranged in different intervals with periodic sub-peaks only detectable with cir-nDNA. The very low amount of cir-mtDNA fragments of short size observed suggested that most of the cir-mtDNA is poorly fragmented and appearing longer than ∼1,000 bp, the readout limit of this LP-WGS method. Data suggested that cir-nDNA is, among DNA extracted in plasma, associated with ∼8.6% of large structures (apoptotic bodies, large extracellular vesicles (EVs), cell debris…), ∼27.7% in chromatin and small EVs and ∼63.7% mainly in oligo- and mono-nucleosomes. By contrast, cir-mtDNA appeared to be preponderantly (75.7%) associated with extracellular mitochondria, either in its free form or with large EVs; to a lesser extent, it was also associated with other structures: small EVs (∼18.4%), and exosomes or protein complexes (∼5.9%). Conclusion: This is the first study to directly compare the structural features of cir-nDNA and cir-mtDNA. The significant differences revealed between both are due to the DNA topological structure contained in the nucleus (chromatin) and in the mitochondria (plasmid) that determine their biological stability in blood. Although cir-nDNA and cir-mtDNA are principally associated with mono-nucleosomes and cell-free mitochondria, our study highlights the diversity of the circulating structures associated with cell-free DNA. They consequently have different pharmacokinetics as well as physiological functions. Thus, any accurate evaluation of their biological or diagnostic individual properties must relies on appropriate pre-analytics, and optimally on the isolation or enrichment of one category of their cirDNA associated structures.

Efficacy of immune checkpoint inhibitors in microsatellite unstable/mismatch repair-deficient advanced pancreatic adenocarcinoma: an AGEO European Cohort.

BACKGROUND: Immune checkpoint inhibitors (ICIs) improve oncological outcomes in patients with microsatellite instability-high (MSI) or mismatch repair-deficient (dMMR) advanced solid tumours. Nevertheless, based on limited published data, the outcome of patients with MSI/dMMR pancreatic ductal adenocarcinoma (PDAC) seems poorer when compared to other malignancies. This multi-institutional analysis sought to assess the efficacy and tolerability of ICIs in a large real-world cohort of patients with MSI/dMMR PDAC. METHODS: We retrospectively collected data from patients with MSI/dMMR advanced PDAC treated with ICIs in 16 centers. Progression-free survival and overall survival were calculated from the start of treatment, and we report objective response and disease control rates according to RECIST V1.1. RESULTS: Thirty-one MSI/dMMR advanced PDAC patients were identified. Twenty-five patients received single-agent anti-PD-1 antibodies, three patients received the combination of nivolumab and ipilimumab and three patients received immunotherapy in combination with chemotherapy. Among 31 evaluable patients, 15 (48.4%) had an objective response (three complete responses and 12 partial responses), and six (19.4%) had stable disease. With a median follow-up of 18 months, the median progression-free survival (PFS) was 26.7 months and the median overall survival (OS) was not reached. Disease control rates (DCRs) among patients with only one line of prior therapy (N = 17) was 76.5%. Grade 3-4 treatment-related adverse events were not observed. CONCLUSION: This retrospective analysis suggests that ICIs are effective and well tolerated in patients with MSI/dMMR advanced PDAC. Hence, our work supports the use of PD-1 inhibition in this group of patients with high unmet medical need.

Improving the response to oxaliplatin by targeting chemotherapy-induced CLDN1 in resistant metastatic colorectal cancer cells.

BACKGROUND: Tumor resistance is a frequent cause of therapy failure and remains a major challenge for the long-term management of colorectal cancer (CRC). The aim of this study was to determine the implication of the tight junctional protein claudin 1 (CLDN1) in the acquired resistance to chemotherapy. METHODS: Immunohistochemistry was used to determine CLDN1 expression in post-chemotherapy liver metastases from 58 CRC patients. The effects of oxaliplatin on membrane CLDN1 expression were evaluated by flow cytometry, immunofluorescence and western blotting experiments in vitro and in vivo. Phosphoproteome analyses, proximity ligation and luciferase reporter assays were used to unravel the mechanism of CLDN1 induction. RNAseq experiments were performed on oxaliplatin-resistant cell lines to investigate the role of CLDN1 in chemoresistance. The "one-two punch" sequential combination of oxaliplatin followed by an anti-CLDN1 antibody-drug conjugate (ADC) was tested in both CRC cell lines and murine models. RESULTS: We found a significant correlation between CLDN1 expression level and histologic response to chemotherapy, CLDN1 expression being the highest in resistant metastatic residual cells of patients showing minor responses. Moreover, in both murine xenograft model and CRC cell lines, CLDN1 expression was upregulated after exposure to conventional chemotherapies used in CRC treatment. CLDN1 overexpression was, at least in part, functionally related to the activation of the MAPKp38/GSK3ß/Wnt/ß-catenin pathway. Overexpression of CLDN1 was also observed in oxaliplatin-resistant CRC cell lines and was associated with resistance to apoptosis, suggesting an anti-apoptotic role for CLDN1. Finally, we demonstrated that the sequential treatment with oxaliplatin followed by an anti-CLDN1 ADC displayed a synergistic effect in vitro and in in vivo. CONCLUSION: Our study identifies CLDN1 as a new biomarker of acquired resistance to chemotherapy in CRC patients and suggests that a "one-two punch" approach targeting chemotherapy-induced CLDN1 expression may represent a therapeutic opportunity to circumvent resistance and to improve the outcome of patients with advanced CRC.

Stereotactic MR-Guided Radiotherapy for Liver Metastases: First Results of the Montpellier Prospective Registry Study.

Liver stereotactic body radiotherapy (SBRT) is a local treatment that provides good local control and low toxicity. We present the first clinical results from our prospective registry of stereotactic MR-guided radiotherapy (MRgRT) for liver metastases. All patients treated for liver metastases were included in this prospective registry study. Stereotactic MRgRT indication was confirmed by multidisciplinary specialized tumor boards. The primary endpoints were acute and late toxicities. The secondary endpoints were survival outcomes (local control, overall survival (OS), disease-free survival, intrahepatic relapse-free survival). Twenty-six consecutive patients were treated for thirty-one liver metastases between October 2019 and April 2022. The median prescribed dose was 50 Gy (40-60) in 5 fractions. No severe acute MRgRT-related toxicity was noted. Acute and late gastrointestinal and liver toxicities were low and mostly unrelated to MRgRT. Only 5 lesions (16.1%) required daily adaptation because of the proximity of organs at risk (OAR). With a median follow-up time of 17.3 months since MRgRT completion, the median OS, 1-year OS and 2-year OS rates were 21.7 months, 83.1% (95% CI: 55.3-94.4%) and 41.6% (95% CI: 13.5-68.1%), respectively, from MRgRT completion. The local control at 6 months, 1 year and 2 years was 90.9% (95% CI: 68.3-97.7%). To our knowledge, we report the largest series of stereotactic MRgRT for liver metastases. The treatment was well-tolerated and achieved a high LC rate. Distant relapse remains a challenge in this population.

A straightforward method to quantify circulating mRNAs as biomarkers of colorectal cancer.

Optimizing the biomarker combination to be analyzed in liquid biopsies should improve personalized medicine. We developed a method to purify circulating cell-free mRNAs from plasma samples and to quantify them by RT-qPCR. We selected three candidate colorectal cancer biomarkers (B2M, TIMP-1, and CLU). Their mRNA levels were significantly higher in plasma of patients with metastatic colorectal cancer patients (mCRC) (n = 107) than in healthy individuals (HI) (n = 53). To increase the discriminating performance of our method, we analyzed the sum of the three mRNA levels (BTC index). The area under the ROC curve (AUC) to estimate the BTC index capacity to discriminate between mCRC and HI plasma was 0.903. We also determined the optimal BTC index cut-off to distinguish between plasma samples, with 82% of sensitivity and 93% of specificity. By using mRNA as a novel liquid biopsy analytical parameter, our method has the potential to facilitate rapid screening of CRCm.

Neutrophil extracellular traps have auto-catabolic activity and produce mononucleosome-associated circulating DNA.

BACKGROUND: As circulating DNA (cirDNA) is mainly detected as mononucleosome-associated circulating DNA (mono-N cirDNA) in blood, apoptosis has until now been considered as the main source of cirDNA. The mechanism of cirDNA release into the circulation, however, is still not fully understood. This work addresses that knowledge gap, working from the postulate that neutrophil extracellular traps (NET) may be a source of cirDNA, and by investigating whether NET may directly produce mono-N cirDNA. METHODS: We studied (1) the in vitro kinetics of cell derived genomic high molecular weight (gHMW) DNA degradation in serum; (2) the production of extracellular DNA and NET markers such as neutrophil elastase (NE) and myeloperoxidase (MPO) by ex vivo activated neutrophils; and (3) the in vitro NET degradation in serum; for this, we exploited the synergistic analytical information provided by specifically quantifying DNA by qPCR, and used shallow WGS and capillary electrophoresis to perform fragment size analysis. We also performed an in vivo study in knockout mice, and an in vitro study of gHMW DNA degradation, to elucidate the role of NE and MPO in effecting DNA degradation and fragmentation. We then compared the NET-associated markers and fragmentation size profiles of cirDNA in plasma obtained from patients with inflammatory diseases found to be associated with NET formation and high levels of cirDNA (COVID-19, N = 28; systemic lupus erythematosus, N = 10; metastatic colorectal cancer, N = 10; and from healthy individuals, N = 114). RESULTS: Our studies reveal that gHMW DNA degradation in serum results in the accumulation of mono-N DNA (81.3% of the remaining DNA following 24 h incubation in serum corresponded to mono-N DNA); "ex vivo" NET formation, as demonstrated by a concurrent 5-, 5-, and 35-fold increase of NE, MPO, and cell-free DNA (cfDNA) concentration in PMA-activated neutrophil culture supernatant, leads to the release of high molecular weight DNA that degrades down to mono-N in serum; NET mainly in the form of gHMW DNA generate mono-N cirDNA (2 and 41% of the remaining DNA after 2 h in serum corresponded to 1-10 kbp fragments and mono-N, respectively) independent of any cellular process when degraded in serum; NE and MPO may contribute synergistically to NET autocatabolism, resulting in a 25-fold decrease in total DNA concentration and a DNA fragment size profile similar to that observed from cirDNA following 8 h incubation with both NE and MPO; the cirDNA size profile of NE KO mice significantly differed from that of the WT, suggesting NE involvement in DNA degradation; and a significant increase in the levels of NE, MPO, and cirDNA was detected in plasma samples from lupus, COVID-19, and mCRC, showing a high correlation with these inflammatory diseases, while no correlation of NE and MPO with cirDNA was found in HI. CONCLUSIONS: Our work describes the mechanisms by which NET and cirDNA are linked. In doing so, we demonstrate that NET are a major source of mono-N cirDNA independent of apoptosis and establish a new paradigm of the mechanisms of cirDNA release in normal and pathological conditions. We also demonstrate a link between immune response and cirDNA.

The desmoplastic growth pattern is associated with second-stage completion and longer survival in 2-stage hepatectomy for colorectal cancer liver metastases.

BACKGROUND: Two-stage hepatectomy for bilobar colorectal cancer liver metastases is potentially curative for selected patients. Histological growth patterns of colorectal liver metastases (desmoplastic, replacement, and pushing) have prognostic value. Our aim was to evaluate their association with pathologic response to preoperative treatment, second-stage hepatectomy completion, and survival in patients treated with a curative-intent 2-stage hepatectomy. METHODS: In 67 patients planned for 2-stage hepatectomy, colorectal liver metastases resected from the first-stage hepatectomy were retrospectively evaluated for growth patterns and pathologic response according to Tumor Regression Grading, modified Tumor Regression Grading, and Blazer grading. Tumor Regression Grading 1 to 3, modified Tumor Regression Grading 1 to 3, and Blazer 0 and 1 defined good responders. RESULTS: Desmoplastic growth patterns (GP) were more frequent among good responders (P < .001). Second-stage hepatectomy completion was associated with desmoplastic growth patterns and pathologic response on univariate analysis and multivariable analyses (P = .017 and P = .041, respectively). Median follow-up was 84 months (95% confidence interval: 53.4 [not reached]). Nondesmoplastic GP patients and nonresponders had a poorer overall survival (hazard ratio = 3.86, 95% confidence interval: 2.11-7.07, P < .001 and hazard ratio = 2.14, 95% confidence interval: 1.19-3.83, P = .009, respectively) on univariate analysis. Nondesmoplastic growth pattern was the only factor associated with a poorer overall survival on multivariable analysis (hazard ratio = 4.17, 95% confidence interval: 1.79-9.74, P < .001). Nondesmoplastic GP was also associated with a poorer recurrence-free survival (hazard ratio = 2.05, 95% confidence interval: 1.13-3.70, P = .017). CONCLUSION: Desmoplastic GP could represent a useful morphological marker for early identification of patients who might benefit from 2-stage hepatectomy completion.

Mechanical signatures of human colon cancers.

Besides the standard parameters used for colorectal cancer (CRC) management, new features are needed in clinical practice to improve progression-free and overall survival. In some cancers, the microenvironment mechanical properties can contribute to cancer progression and metastasis formation, or constitute a physical barrier for drug penetration or immune cell infiltration. These mechanical properties remain poorly known for colon tissues. Using a multidisciplinary approach including clinical data, physics and geostatistics, we characterized the stiffness of healthy and malignant colon specimens. For this purpose, we analyzed a prospective cohort of 18 patients with untreated colon adenocarcinoma using atomic force microscopy to generate micrometer-scale mechanical maps. We characterized the stiffness of normal epithelium samples taken far away or close to the tumor area and selected tumor tissue areas. These data showed that normal epithelium was softer than tumors. In tumors, stroma areas were stiffer than malignant epithelial cell areas. Among the clinical parameters, tumor left location, higher stage, and RAS mutations were associated with increased tissue stiffness. Thus, in patients with CRC, measuring tumor tissue rigidity may have a translational value and an impact on patient care.

[hPG80 and cancer: A new blood biomarker in development for patient monitoring]. / hPG80 et cancer : un nouveau biomarqueur sanguin en développement pour le suivi des patients.

Recent technological advances coupled with our improved understanding of the molecular and cellular mechanisms associated with cancer development have enabled better overall patient care. Among the newly identified biomarkers such as circulating tumor DNA or circulating tumor cells, hPG80 (circulating progastrin) that is easy to detect and quantify by a simple ELISA assay has the potential to become a new routine clinical tool in oncology if on-going studies validated its utility. Indeed, on the one hand, hPG80 was found in the blood of patients with different tumors (colorectal, pancreatic, liver, lung, stomach, kidney cancers) at a significantly higher concentration than in healthy donors. Moreover, some studies suggested a potential association between hPG80 concentration changes and anti-cancer treatment efficacy in patients with gastro-intestinal and hepatocellular carcinomas. Finally, hPG80 might be a prognostic factor for overall survival in metastatic renal cell carcinoma cancer (mRCC) and in hepatocellular carcinoma (HCC). If these hypotheses were validated, hPG80 might help better stratify patients according to their prognosis, and also become a tool to monitor relapse and predict treatment response. Prospective validation studies are on-going.

Impact of trough concentrations of regorafenib and its major metabolites M-2 and M-5 on overall survival of chemorefractory metastatic colorectal cancer patients: Results from a multicentre GERCOR TEXCAN phase II study.

PURPOSE: This prospective pharmacokinetic (PK) ancillary study of the TEXCAN phase II GERCOR trial of patients with chemorefractory metastatic colorectal cancer and treated with regorafenib (REGO) investigated correlations between overall survival (OS) and concentrations (C) of REGO and its active metabolites, M-2 and M-5. METHODS: 55 patients received REGO 160 mg/day for 21 days of a 28-day cycle (NCT02699073). REGO, M-2, M-5 were measured by liquid chromatography-mass spectrometry assay on day 15 of cycle 1 (C1) and 2 (C2). We studied the association between OS and Cmin of REGO, M-2 and M-5 at C1 and their accumulations between C1 and C2. RESULTS: Medians of C2/C1 M-2 and M-5 ratios were 0.82 (interquartile range 0.50-1.78) and 0.75 (interquartile range 0.41-1.93), respectively. Patients with C2/C1 M-2 ratio ≥ median had improved survival compared to those < median (12.6 versus 4.0 months, P = 0.023), corresponding to a 66% mortality risk reduction in multivariate analysis. The C2/C1 M-2 ratio correlated with C1 REGO+M-2+M-5 (Csum; P = 0.006). Restricted cubic spline analysis showed an increased OS benefit as the C2/C1 M-2 ratio raises and when C1 Csum ranged between 2.5 and 5.5 mg/L. Patients within the Csum range had a reduced incidence of serious adverse events and improved OS. CONCLUSIONS: We identified PK parameters associated with a survival benefit in patients with metastatic colorectal cancer treated by REGO. OS and safety were favourable when C1 REGO+M-2+M-5 Csum ranged between 2.5 and 5.5 mg/L. These results pave the way for individual REGO dose modification strategies based on PK monitoring. CLINICAL TRIAL REFERENCE: NCT02699073.

Association of neutrophil extracellular traps with the production of circulating DNA in patients with colorectal cancer.

We postulate that a significant part of circulating DNA (cirDNA) originates in the degradation of neutrophil extracellular traps (NETs). In this study, we examined the plasma level of two markers of NETs (myeloperoxidase (MPO) and neutrophil elastase (NE)), as well as cirDNA levels in 219 patients with a metastatic colorectal cancer (mCRC), and in 114 healthy individuals (HI). We found that in patients with mCRC the content of these analytes was (i) highly correlated, and (ii) all statistically different (p < 0.0001) than in HI (N = 114). These three NETs markers may readily distinguish between patients with mCRC from HI, (0.88, 0.86, 0.84, and 0.95 AUC values for NE, MPO, cirDNA, and NE + MPO + cirDNA, respectively). Concomitant analysis of anti-phospholipid (anti-cardiolipin), NE, MPO, and cirDNA plasma concentrations in patients with mCRC might have value for thrombosis prevention, and suggested that NETosis may be a critical factor in the immunological response/phenomena linked to tumor progression.