Nuevas terapias basadas en dianas moleculares en cáncer colorrectal metastásico

El desarrollo de nuevas drogas en cáncer colorrectal ha pasado por una etapa previa indispensable, basada en el conocimiento de la biología tumoral de la enfermedad que median el crecimiento tumoral, ciclo celular, apoptosis, angiogénesis e invasión. Existen múltiples fármacos en fase de desarrollo que han sido diseñados de forma específica para bloquear distintos mecanismos biológicos fundamentales para la progresión tumoral. El objetivo de este trabajo, es llevar a cabo una revisión de la situación actual de los nuevos fármacos basados en dianas moleculares que se estan desarrollando en el cáncer colorrectal metastásico.El desenvolupament de noves drogues en càncer colorrectal ha passat per una etapa prèvia indispensable, basada en el coneixement de la biologia tumoral de la malaltia que facilita el creixement tumoral, cicle cel·lular, apoptosi, angiogènesi i inivasió. Existeixen múltiples fàrmacs en fase de desenvolupament que han estat dissenyats de forma específica per bloquejar diversos mecanismes biològics fonamentals per la progressió tumoral. L'objectiu d'aquest treball és dur a terme una revisió de la situació actual dels nous fàrmacs basats en dianes mol·leculars que s'estan desenvolupant en el càncer colorrectal metastatic

Epigenetic homogeneity within colorectal tumors predicts shorter relapse-free and overall survival times for patients with locoregional cancer

Background & aims: there are few validated biomarkers that can be used to predict outcomes for patients with colorectal cancer. Part of the challenge is the genetic and molecular heterogeneity of colorectal tumors not only among patients, but also within tumors. We have explored intratumor heterogeneity at the epigenetic level, due to its dynamic nature. We analyzed DNA methylation profiles of the digestive tract surface and the central bulk and invasive front regions of colorectal tumors. Methods: we determined the DNA methylation profiles of >450,000 CpG sites in 3 macrodissected regions of 79 colorectal tumors and 23 associated liver metastases, obtained from 2 hospitals in Spain. We also analyzed samples for KRAS and BRAF mutations, 499,170 single nucleotide polymorphisms, and performed immunohistochemical analyses. Results: we observed differences in DNA methylation among the 3 tumor sections; regions of tumor−host interface differed the most from the other tumor sections. Interestingly, tumor samples collected from areas closer to the gastrointestinal transit most frequently shared methylation events with metastases. When we calculated individual coefficients to quantify heterogeneity, we found that epigenetic homogeneity was significantly associated with short time of relapse-free survival (log-rank P = .037) and short time of overall survival (log-rank P = .026) in patients with locoregional colorectal cancer. Conclusions: in an analysis of 79 colorectal tumors, we found significant heterogeneity in patterns of DNA methylation within each tumor; the level of heterogeneity correlates with times of relapse-free and overall survival

Phase II study of necitumumab plus modified FOLFOX6 as first-line treatment in patients with locally advanced or metastatic colorectal cancer

This single-arm phase II study investigated the EGFR monoclonal antibody necitumumab plus modified FOLFOX6 (mFOLFOX6) in first-line treatment of locally advanced or metastatic colorectal cancer (mCRC). Patients received 800-mg intravenous necitumumab (day 1; 2-week cycles), followed by oxaliplatin 85 mg m −2, folinic acid 400 mg m −2, and 5-fluorouracil (400 mg m −2 bolus then 2400 mg m −2 over 46 h). Radiographic evaluation was performed every 8 weeks until progression. Primary endpoint was objective response rate. Forty-four patients were enrolled and treated. Objective response rate was 63.6% (95% confidence interval 47.8-77.6); complete response was observed in four patients; median duration of response was 10.0 months (7.0-16.0). Median overall survival (OS) and progression-free survival (PFS) were 22.5 (11.0-30.0) and 10.0 months (7.0-12.0), respectively. Clinical outcome was better in patients with KRAS exon 2 wild type (median OS 30.0 months (23.0-NA); median PFS 12.0 (8.0-20.0)), compared with KRAS exon 2 mutant tumours (median OS 7.0 months (5.0-37.0); median PFS 7.0 (4.0-18.0)). The most common grade ⩾3 adverse events were neutropenia (29.5%), asthenia (27.3%), and rash (20.5%). First-line necitumumab+mFOLFOX6 was active with manageable toxicity in locally advanced or mCRC; additional evaluation of the impact of tumour RAS mutation status is warranted

Epigenetic activation of a cryptic TBC1D16 transcript enhances melanoma progression by targeting EGFR

Metastasis is respoMetastasis is responsible for most cancer-related deaths, and, among common tumor types, melanoma is one with great potential to metastasize. Here we study the contribution of epigenetic changes to the dissemination process by analyzing the changes that occur at the DNA methylation level between primary cancer cells and metastases. We found a hypomethylation event that reactivates a cryptic transcript of the Rab GTPase activating protein TBC1D16 (TBC1D16-47 kDa; referred to hereafter as TBC1D16-47KD) to be a characteristic feature of the metastatic cascade. This short isoform of TBC1D16 exacerbates melanoma growth and metastasis both in vitro and in vivo. By combining immunoprecipitation and mass spectrometry, we identified RAB5C as a new TBC1D16 target and showed that it regulates EGFR in melanoma cells. We also found that epigenetic reactivation of TBC1D16-47KD is associated with poor clinical outcome in melanoma, while conferring greater sensitivity to BRAF and MEK inhibitors

Analysis of mutant allele fractions in driver genes in colorectal cancer - biological and clinical insights

Sequencing of tumors is now routine and guides personalized cancer therapy. Mutant allele fractions (s, or the 'mutation dose') of a driver gene may reveal the genomic structure of tumors and influence response to targeted therapies. We performed a comprehensive analysis of s of driver alterations in unpaired primary and metastatic colorectal cancer () at our institution from 2010 to 2015 and studied their potential clinical relevance. Of 763 samples, 622 had detailed annotation on overall survival in the metastatic setting (met) and 89 received targeted agents matched to ( inhibitors), ( inhibitors), or 3 mutations (3K pathway inhibitors). s of each variant were normalized for tumor purity in the sample (adjs). We found lower adjs for 600E and 3 than for , , and non-V600 variants. 53 and 600E adjs were higher in metastases as compared to primary tumors, and high adjs were found in metastases of patients with wild-type primary tumors previously exposed to antibodies. Patients with - or 600E -mutated tumors, irrespective of adjs, had worse met. There was no significant association between adjs and time to progression on targeted therapies matched to , , or 3 mutations, potentially related to the limited antitumor activity of the employed drugs (overall response rate of 4.5%). In conclusion, the lower 600E and 3 adjs in subsets of primary tumors indicate subclonality of these driver genes. Differences in adjs between metastases and primary tumors suggest that approved therapies may result in selection of 600E - and -resistant clones and an increase in genomic heterogeneity with acquired 53 alterations. Despite significant differences in prognosis according to mutations in driver oncogenes, adjs levels did not impact on survival and did not help predict benefit with matched targeted agents in the metastatic setting

Concordance of blood- and tumor-based detection of RAS mutations to guide anti-EGFR therapy in metastatic colorectal cancer

Circulating tumor DNA (ctDNA) is a potential source for tumor genome analysis. We explored the concordance between the mutational status of RAS in tumor tissue and ctDNA in metastatic colorectal cancer (mCRC) patients to establish eligibility for anti-epidermal growth factor receptor (EGFR) therapy. A prospective-retrospective cohort study was carried out. Tumor tissue from 146 mCRC patients was tested for RAS status with standard of care (SoC) PCR techniques, and Digital PCR (BEAMing) was used both in plasma and tumor tissue. ctDNA BEAMing RAS testing showed 89.7% agreement with SoC (Kappa index 0.80; 95% CI 0.71 − 0.90) and BEAMing in tissue showed 90.9% agreement with SoC (Kappa index 0.83; 95% CI 0.74 − 0.92). Fifteen cases (10.3%) showed discordant tissue-plasma results. ctDNA analysis identified nine cases of low frequency RAS mutations that were not detected in tissue, possibly due to technical sensitivity or heterogeneity. In six cases, RAS mutations were not detected in plasma, potentially explained by low tumor burden or ctDNA shedding. Prediction of treatment benefit in patients receiving anti-EGFR plus irinotecan in second- or third-line was equivalent if tested with SoC PCR and ctDNA. Forty-eight percent of the patients showed mutant allele fractions in plasma below 1%. Plasma RAS determination showed high overall agreement and captured a mCRC population responsive to anti-EGFR therapy with the same predictive level as SoC tissue testing. The feasibility and practicality of ctDNA analysis may translate into an alternative tool for anti-EGFR treatment selection

Nuevas terapias en cáncer colorrectal metastásico refractario: papel de los fármacos que interfieren en la vía de met e integrinas

Penden

Nuevas terapias basadas en dianas moleculares en cáncer colorrectal metastásico

El desarrollo de nuevas drogas en cáncer colorrectal ha pasado por una etapa previa indispensable, basada en el conocimiento de la biología tumoral de la enfermedad que median el crecimiento tumoral, ciclo celular, apoptosis, angiogénesis e invasión. Existen múltiples fármacos en fase de desarrollo que han sido diseñados de forma específica para bloquear distintos mecanismos biológicos fundamentales para la progresión tumoral. El objetivo de este trabajo, es llevar a cabo una revisión de la situación actual de los nuevos fármacos basados en dianas moleculares que se estan desarrollando en el cáncer colorrectal metastásico.El desenvolupament de noves drogues en càncer colorrectal ha passat per una etapa prèvia indispensable, basada en el coneixement de la biologia tumoral de la malaltia que facilita el creixement tumoral, cicle cel•lular, apoptosi, angiogènesi i inivasió. Existeixen múltiples fàrmacs en fase de desenvolupament que han estat dissenyats de forma específica per bloquejar diversos mecanismes biològics fonamentals per la progressió tumoral. L’objectiu d’aquest treball és dur a terme una revisió de la situació actual dels nous fàrmacs basats en dianes mol•leculars que s’estan desenvolupant en el càncer colorrectal metastatic

Delphi consensus for the third-line treatment of metastatic colorectal cancer

Purpose: The optimal drug regimen and sequence are still unknown for patients with metastatic colorectal cancer (mCRC) who are candidates for third-line (3L) or subsequent treatment. The aim of this study is to know the opinion of experts on the most appropriate treatment options for mCRC in 3L and to clarify certain clinical decisions in Spain. Methods: Using a modified Delphi method, a group of experts discussed the treatment in 3L of patients with mCRC and developed a questionnaire with 21 items divided into 5 sections. Results: After 2 rounds, the 67 panelists consulted agreed on 17 items (81%). They considered that the main objective of 3L is to equally increase survival and improve patients' quality of life (QoL), but preferably the QoL. It was agreed that patients with mCRC in 3L prefer to receive active versus symptomatic treatment. Panelists considered trifluridine/tipiracil (FTD/TPI) to be the best oral treatment available to them in 3L. In patients with MSI-H or dMMR and BRAF V600E, the panelists mostly prefer targeted treatments. Panelists agreed the use of a therapeutic sequence that not only increases outcomes but also allows patients to be treated later. Finally, it was agreed that FTD/TPI has a mechanism of action that allows it to be used in patients refractory to previous treatment with 5-fluorouracil. Conclusion: The experts agreed with most of the proposed items on 3L treatment of mCRC, prioritizing therapeutic options that increase survival and preserve QoL, while facilitating the possibility that patients can continue to be treated later.Depto. de MedicinaFac. de MedicinaTRUEpubAPC financiada por la UC

Combined Treatment with Immunotherapy-Based Strategies for MSS Metastatic Colorectal Cancer

In recent years, deepening knowledge of the complex interactions between the immune system and cancer cells has led to the advent of effective immunotherapies that have revolutionized the therapeutic paradigm of several cancer types. However, colorectal cancer (CRC) is one of the tumor types in which immunotherapy has proven less effective. While there is solid clinical evidence for the therapeutic role of immune checkpoint inhibitors in mismatch repair-deficient (dMMR) and in highly microsatellite instable (MSI-H) metastatic CRC (mCRC), blockade of CTLA-4 or PD-L1/PD-1 as monotherapy has not conferred any major clinical benefit to patients with MMR-proficient (pMMR) or microsatellite stable (MSS) mCRC, reflecting 95% of the CRC population. There thus remains a high unmet medical need for the development of novel immunotherapy approaches for the vast majority of patients with pMMR or MSS/MSI-low (MSI-L) mCRC. Defining the molecular mechanisms for immunogenicity in mCRC and mediating immune resistance in MSS mCRC is needed to develop predictive biomarkers and effective therapeutic combination strategies. Here we review available clinical data from combinatorial therapeutic approaches using immunotherapy-based strategies for MSS mCRC