Landscape of transcriptome variations uncovering known and novel driver events in colorectal carcinoma

We focused on an integrated view of genomic changes in Colorectal cancer (CRC) and distant normal colon tissue (NTC) to test the effectiveness of expression profiling on identification of molecular targets. We performed transcriptome on 16 primary coupled CRC and NTC tissues. We identified pathways and networks related to pathophysiology of CRC and selected potential therapeutic targets. CRC cells have multiple ways to reprogram its transcriptome: a functional enrichment analysis in 285 genes, 25% mutated, showed that they control the major cellular processes known to promote tumorigenesis. Among the genes showing alternative splicing, cell cycle related genes were upregulated (CCND1, CDC25B, MCM2, MCM3), while genes involved in fatty acid metabolism (ACAAA2, ACADS, ACAT1, ACOX, CPT1A, HMGCS2) were downregulated. Overall 148 genes showed differential splicing identifying 17 new isoforms. Most of them are involved in the pathogenesis of CRC, although the functions of these variants remain unknown. We identified 2 in-frame fusion events, KRT19-KRT18 and EEF1A1-HSP90AB1, encoding for chemical proteins in two CRC patients. We draw a functional interactome map involving integrated multiple genomic features in CRC. Finally, we underline that two functional cell programs are prevalently deregulated and absolutely crucial to determinate and sustain CRC phenotype.

KRAS and BRAF Mutations as Prognostic and Predictive Biomarkers for Standard Chemotherapy Response in Metastatic Colorectal Cancer: A Single Institutional Study

KRAS mutation is a confirmed predictive biomarker for anti-EGFR monoclonal antibody therapy response for metastatic colorectal cancer. However, its prognosis impact and the predictive potential for first-line standard chemotherapy remains unclear. On the other hand, V600E mutation is the most frequent and studied mutation in the BRAF gene, and it has been associated with a poor outcome of patients and a low response to anti-EGFR treatment. Thus, the aim of this study is to evaluate the role of KRAS and BRAF mutations as prognosis factors and predictive biomarkers for 1st line standard chemotherapy in metastatic colorectal cancer. KRAS mutations and BRAF V600E mutations exhibited a poor outcome (p = 0.021 and p < 0.0001, respectively). Cox multivariate analysis showed that the presence of liver metastasis (HR = 1.595; 95% CI: 1.086–2.343; p = 0.017), KRAS mutation (HR = 1.643; 95% CI: 1.110–2.431; p = 0.013) and BRAF V600E mutation (HR = 5.861; 95% CI: 2.531–13.570; p < 0.0001) were statistically significant co-variables for progression-free survival. Interestingly, patients with KRAS mutations were associated with a poor response to first line standard chemotherapy (p = 0.008). In contrast, the BRAF V600E mutation did not have any impact on the first line standard chemotherapy response (p = 0.540). Therefore, in the present study, we provide new insight on the role of KRAS and BRAF, not only as prognosis biomarkers, but also as first line standard chemotherapy response biomarkers in metastatic colorectal cancer.

Nomograms for Prediction of Molecular Phenotypes in Colorectal Cancer

Background

Colorectal cancer (CRC) patients with different molecular phenotypes, including microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and somatic mutations in BRAF and KRAS gene, vary in treatment response and prognosis. However, molecular phenotyping under adequate quality control in a community-based setting may be difficult. We aimed to build the nomograms based on easily accessible clinicopathological characteristics to predict molecular phenotypes.

Methods

Three hundred and six patients with pathologically confirmed stage I-IV CRC were included in the cohort. The assays for MSI, CIMP, and mutations in BRAF and KRAS gene were performed using resected tumor samples. The candidate predictors were identified from clinicopathological variables using multivariate Logistic regression analyses to construct the nomograms that could predict each molecular phenotype.

Results

The incidences of MSI, CIMP, BRAF mutation and KRAS mutation were 25.3% (72/285), 2.5% (7/270), 3.4% (10/293), and 34.8% (96/276) respectively. In the multivariate Logistic analysis, poor differentiation and high neutrophil/lymphocyte ratio (NLR) were independently associated with MSI; poor differentiation, high NLR and high carcinoembryonic antigen/tumor size ratio (CSR) were independently associated with CIMP; poor differentiation, lymphovascular invasion and high CSR were independently associated with BRAF mutation; poor differentiation, proximal tumor, mucinous tumor and high NLR were independently associated with KRAS mutation. Four nomograms for MSI, CIMP, BRAF mutation and KRAS mutation were developed based on these independent predictors, the C-indexes of which were 61.22% (95% CI: 60.28–62.16%), 95.57% (95% CI: 95.20–95.94%), 83.56% (95% CI: 81.54–85.58%), and 69.12% (95% CI: 68.30–69.94%) respectively.

Conclusion

We established four nomograms using easily accessible variables that could well predict the presence of MSI, CIMP, BRAF mutation and KRAS mutation in CRC patients.

Prediction of Drug Efficacy in Colon Cancer Preclinical Models Using a Novel Ranking Method of Gene Expression

The presence of stromal cells in tumors is altering the significance of molecular profiling when using standard methods of gene expression quantification. We developed a novel normalization method to rank target gene expression in tumor samples by comparisons with reference samples representing the different cell types found in a tumor. The score for each target gene obtained after normalization, is aimed to be predictive of targeted therapies efficiency. We performed this qPCR analysis on human colorectal cancers to demonstrate the importance of reference samples to obtain accurate data and on a collection of patient-derived xenografted (PDX) colon tumors treated with Cetuximab (anti-EGFR) to demonstrate that the calculated EGFR score is predictive of Cetuximab efficacy. Interestingly, the score allowed to select an efficient treatment in a PDX model refractory to standard of care. This method is opening a novel way to predict targeted therapy efficiency which could be extended to several tumor types, and to unlimited target genes.

Tumor sidedness and efficacy of first-line therapy in patients with RAS/BRAF wild-type metastatic colorectal cancer: A network meta-analysis

We conducted a systemic search of several databases for randomized controlled trials (RCTs) that reported efficacy and safety outcomes of drugs for left-sided and right-sided metastatic colorectal cancer (mCRC), to identify the best available treatment. A network meta-analysis with mixed comparisons was created to interpret the best treatment option using the surface under the cumulative ranking curve. In the left-sided rat sarcoma (RAS) wild-type (WT) mCRC patients, bevacizumab, panitumumab, or cetuximab with chemotherapy groups showed a significantly better objective response rate than the chemotherapy alone group. The progression-free survival (PFS) and overall survival were better with panitumumab or cetuximab with chemotherapy than with chemotherapy alone. In the right-sided RAS WT mCRC patients, PFS for bevacizumab with chemotherapy was significantly better than that for cetuximab with chemotherapy. Cetuximab, closely followed by panitumumab, is the most effective treatment in left-sided RAS WT mCRC. Bevacizumab is more effective in right-sided mCRC.

Use of High-Cost Cancer Treatments in Academic and Nonacademic Practice

BACKGROUND

Academic physicians, such as those affiliated with National Cancer Institute (NCI)-designated Comprehensive Cancer Centers, may have different practice patterns regarding the use of high-cost cancer drugs than nonacademic physicians.

MATERIALS AND METHODS

For this cohort study, we linked cancer registry, administrative, and demographic data for patients with newly diagnosed cancer in North Carolina from 2004 to 2011. We selected cancer types with multiple U.S. Food and Drug Administration-approved, National Comprehensive Cancer Network-recommended treatment options and large differences in reimbursement between higher-priced and lower-priced options (stage IV colorectal, stage IV lung, and stage II-IV head-and-neck cancers). We assessed whether provider's practice setting-NCI-designated Comprehensive Cancer Center ("NCI") versus other location ("non-NCI")-was associated with use of higher-cost treatment options. We used inverse probability of exposure weighting to control for patient characteristics.

RESULTS

Of 800 eligible patients, 79.6% were treated in non-NCI settings. Patients treated in non-NCI settings were more likely to receive high-cost treatment than patients treated in NCI settings (36.0% vs. 23.2%), with an unadjusted prevalence difference of 12.7% (95% confidence interval [CI], 5.1%-20.0%). After controlling for potential confounding factors, non-NCI patients remained more likely to receive high-cost treatment, although the strength of association was attenuated (adjusted prevalence difference, 9.6%; 95% CI -0.1%-18.7%). Exploratory analyses suggested potential heterogeneity across cancer type and insurance status.

CONCLUSION

Use of higher-cost cancer treatments may be more common in non-NCI than NCI settings. This may reflect differential implementation of clinical evidence, local practice variation, or possibly a response to the reimbursement incentives presented by chemotherapy billing.

IMPLICATIONS FOR PRACTICE

Oncology care delivery and practice patterns may vary between care settings. By comparing otherwise similar patients treated in National Cancer Institute (NCI)-designated Comprehensive Cancer Centers with those treated elsewhere, this study suggests that patients may be more likely to receive treatment with certain expensive cancer drugs if treated in the non-NCI setting. These practice differences may result in differences in patient costs and outcomes as a result of where they receive treatment.

Prevalence of RAS and BRAF mutations in metastatic colorectal cancer patients by tumor sidedness: A systematic review and meta-analysis

Studies have shown that the prevalence of RAS and BRAF mutations may differ by tumor sidedness among metastatic colorectal cancer (mCRC) patients. Both mutation status and tumor sidedness may impact survival and disease progression and RAS mutation status has been shown to predict response to anti‐epidermal growth factor receptor (EGFR) therapy. A systematic literature review and meta‐analysis were conducted to estimate the pooled prevalence of RAS and BRAF mutations by tumor sidedness in studies of mCRC patients. Forty‐four studies comprising 15 981 mCRC patients tested for RAS and/or BRAF mutations were included in the meta‐analyses. The prevalence of RAS mutations differed significantly by tumor side (32.4% among left‐sided tumors, 41.3% among right‐sided tumors; P = .017), as did the prevalence of KRAS mutations (35.8% among left‐sided tumors, 46.3% among right‐sided tumors; P < .0001) and BRAF mutations (4.3% among left‐sided tumors, 16.3% among right‐sided tumors; P < .0001). Among right‐sided tumors, the prevalence of RAS and KRAS mutations varied significantly by study design, with higher prevalence among observational studies than clinical trials, and there was significant variation by study location for the prevalence of KRAS mutations in left‐sided tumors and the prevalence of BRAF mutations in right‐sided tumors. These results help to better characterize the mCRC population to better inform clinicians and researchers. Few of the included studies reported overall or progression‐free survival (PFS) by both tumor sidedness and mutation status. As both of these factors may have prognostic impact, future studies should consider evaluating survival by these variables.

Promising Colorectal Cancer Biomarkers for Precision Prevention and Therapy

Colorectal cancer (CRC) has been ranked as the third most prevalent cancer worldwide. Indeed, it represents 10.2% of all cancer cases. It is also the second most common cause of cancer mortality, and accounted for about 9.2% of all cancer deaths in 2018. Early detection together with a correct diagnosis and staging remains the most effective clinical strategy in terms of disease recovery. Thanks to advances in diagnostic techniques, and improvements of surgical adjuvant and palliative therapies, the mortality rate of CRC has decreased by more than 20% in the last decade. Cancer biomarkers for the early detection of CRC, its management, treatment and follow-up have contributed to the decrease in CRC mortality. Herein, we provide an overview of molecular biomarkers from tumor tissues and liquid biopsies that are approved for use in the CRC clinical setting for early detection, follow-up, and precision therapy, and of biomarkers that have not yet been officially validated and are, nowadays, under investigation.

Epidermal growth factor receptor ligands: targets for optimizing treatment of metastatic colorectal cancer

The discovery of epidermal growth factor (EGF) and its receptor (EGFR) revealed the connection between EGF-like ligands, signaling from the EGFR family members and cancer. Over the next fifty years, analysis of EGFR expression and mutation led to the use of monoclonal antibodies to target EGFR in the treatment of metastatic colorectal cancer (mCRC) and this treatment has improved outcomes for patients. The use of the RAS oncogene mutational status has helped to refine patient selection for EGFR antibody therapy, but an effective molecular predictor of likely responders is lacking. This review analyzes the potential utility of measuring the expression, levels and activation of EGF-like ligands and associated processes as prognostic or predictive markers for the identification of patient risk and more effective mCRC therapies.

Characteristics of BRAFV600E Mutant, Deficient Mismatch Repair/Proficient Mismatch Repair, Metastatic Colorectal Cancer: A Multicenter Series of 287 Patients

BACKGROUND

BRAFV600E mutations occurring in about 10% of metastatic colorectal cancers (mCRCs) are usually associated with a poor outcome. However, their prognostic factors are unknown.

MATERIALS AND METHODS

We built a multicenter clinico-biological database gathering data from patients with BRAFV600E -mutant mCRC treated in one of the 16 French centers from 2006 to 2017. The primary endpoint was to identify prognostic factors using a Cox model.

RESULTS

We included 287 patients (median age, 67 years [28-95]; female, 57%). Their median overall survival was 20.8 months (95% confidence interval [CI], 17.97-27.04), and median progression-free survival in the first-line setting was 4.34 months (95% CI, 3.81-5.03). Chemotherapy regimen and biological agents (antiangiogenic or anti-epidermal growth factor receptor) were not associated with overall and progression-free survival. Stage IV disease (synchronous metastases) and absence of curative-intent surgery were statistically associated with poor overall survival. Among the 194 patients with mismatch repair (MMR) status available, overall survival was significantly longer in patients with deficient MMR tumors compared with those with proficient MMR tumors (adjusted hazard ratio = 0.56; p = .009).

CONCLUSION

Despite that BRAFV600E -mutant mCRCs are associated with poor overall and progression-free-survival, patients with deficient MMR tumors and/or resectable disease experienced a longer survival. These results highlight the importance of MMR testing and resectability discussion in patients with BRAFV600E mCRC in day-to-day practice.

IMPLICATIONS FOR PRACTICE

Mismatch repair (MMR) testing and resectability discussion in patients with BRAFV600E metastatic colorectal cancer (mCRC) should be performed in day-to-day practice to steer treatment decision making in patients with BRAFV600E -mutant mCRC.

Negative Hyperselection of Patients With RAS and BRAF Wild-Type Metastatic Colorectal Cancer Who Received Panitumumab-Based Maintenance Therapy

PURPOSE

We assessed the prognostic/predictive role of primary tumor sidedness and uncommon alterations of anti-epidermal growth factor receptor (EGFR) primary resistance (primary resistance in RAS and BRAF wild-type metastatic colorectal cancer patients treated with anti-EGFR monoclonal antibodies [PRESSING] panel) in patients with RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC) who were randomly assigned to panitumumab plus fluorouracil, leucovorin, and oxaliplatin (FOLFOX-4) induction followed by maintenance with panitumumab with or without fluorouracil (FU) plus leucovorin (LV); Valentino trial (ClinicalTrials.gov identifier: NCT02476045).

PATIENTS AND METHODS

This prespecified retrospective analysis included 199 evaluable patients with RAS/BRAF wt. The PRESSING panel included the following: immunohistochemistry (IHC) and in situ hybridization for HER2/MET amplification, IHC with or without RNA sequencing for ALK/ROS1/NTRKs/RET fusions, next-generation sequencing for HER2/PIK3CAex.20/PTEN/AKT1 and RAS mutations with low mutant allele fraction, and multiplex polymerase chain reaction for microsatellite instability. PRESSING status (any positive biomarker v all negative) and sidedness were correlated with overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) in the study population and by treatment arm.

RESULTS

Overall, left- and right-sided tumors were 85.4% and 14.6%, respectively, and PRESSING-negative and -positive tumors were 75.4% and 24.6%, respectively. At a median follow-up of 26 months, inferior outcomes were consistently observed in right- versus left-sided tumors for ORR (55.2% v 74.1%; P = .037), PFS (8.4 v 11.5 months; P = .026), and OS (2-year rate: 50.2% v 65.1%; P = .062). Similar results were observed in the PRESSING-positive versus PRESSING-negative subgroup for ORR (59.2% v 75.3%; P = .030), PFS (7.7 v 12.1 months; P < .001), and OS (2-year rate: 48.1% v 68.1%; P = .021). The PFS benefit of FU plus LV added to panitumumab maintenance, reported in the study, was independent from sidedness and PRESSING status (interaction for PFS P = .293 and .127, respectively). However, outcomes were extremely poor in patients who received single-agent panitumumab and had right-sided tumors (median PFS, 7.7 months; 2-year OS, 38.5%) or PRESSING-positive tumors (median PFS, 7.4 months; 2-year OS, 47.0%).

CONCLUSION

The combined assessment of sidedness and molecular alterations of anti-EGFR primary resistance identified a consistent proportion of patients with RAS/BRAF-wt mCRC who had inferior benefit from initial anti-EGFR-based regimens, particularly after maintenance with single-agent anti-EGFRs.

Circulating tumor DNA/circulating tumor cells and the applicability in different causes induced hepatocellular carcinoma

In 2015, liquid biopsy was rated one of the top 10 breakthrough technologies of the year by MIT Technology Review. Liquid biopsy is a type of in vitro diagnostic method involving a noninvasive blood test. It is also a breakthrough technology used to detect tumors and cancers and assist in therapeutic strategies. The most widely used markers are circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). Primary carcinoma of the liver is a malignancy of hepatocytes or intrahepatic biliary epithelial cells. The most common type of liver cancer is hepatocellular carcinoma (HCC), the causes of which mainly include infection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV), alcohol abuse, aflatoxicosis, and nonalcoholic fatty liver disease/ nonalcoholic steatohepatitis. As there are few typical clinical characteristics during the early stage of the disease, early diagnosis of HCC is very challenging. However, CTCs and ctDNA carry tumor-specific information. Therefore, the detection and analysis of CTCs and ctDNA can provide evidence for the early diagnosis of HCC and guide treatment. Furthermore, several studies have indicated that different inducers of HCC cause different DNA mutations, and accordingly, detection of specific mutations in ctDNA will facilitate the determination of the HCC type and help physicians provide distinctive therapies.

MicroRNA-141-3p affected proliferation, chemosensitivity, migration and invasion of colorectal cancer cells by targeting EGFR

Colorectal cancer (CRC) is one of the most often diagnosed cancers globally. MicroRNAs are small RNA molecules that play essential roles in tumorigenesis and progression of CRC. Here we evaluated the effects of miR-141-3p on growth, cetuximab sensitivity, migration and invasion of CRC cells. We found that miR-141-3p negatively regulated the proliferation, migration and invasion in CRC cells. In addition, miR-141-3p enhanced the cetuximab sensitivity of CRC cells by EGFR suppression. Moreover, miR-141-3p improved cetuximab-induced apoptosis in CRC cells. Furthermore, miR-141-3p altered the expression of E-cadherin, N-cadherin, snail and Vimentin, indicating miR-141-3p might play a role on epithelial to mesenchymal transition (EMT). Luciferase reporter assay showed that EGFR was the direct binding site of miR-141-3p and the expression levels of p-EGFR, Raf-1, pAKT and p-ERK1/2 were regulated by miR-141-3p. After down-regulation of EGFR by siRNA in CRC cells, the effects of miR-141-3p on proliferation, migration and invasion were reversed. miR-141-3p played important roles in CRC growth and response to cetuximab treatment, and might function as a potential biomarker to predict cetuximab response.

Efficacy and safety of anti-EGFR monoclonal antibodies combined with different chemotherapy regimens in patients with RAS wild-type metastatic colorectal cancer: A meta-analysis

OBJECTIVES

To investigate the efficacy and safety of adding anti-epidermal growth factor receptor [EGFR] MoAbs to various chemotherapy regimens in patients with RAS wild-type metastasized colorectal cancer (RAS WT metastatic colorectal cancer [mCRC]) and to identify the optimal combination regimens.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL from the inception date to 20th May 2019. Randomized clinical trials investigating chemotherapy with or without anti-EGFR MoAbs in treatment of patients with RAS WT mCRC were included.

RESULTS

Eighteen studies involving 8848 participants were eligible. Comparing with oxaliplatin-based chemotherapy, adding anti-EGFR MoAbs benefited only in progression-free survival (PFS) (hazard ratio [HR] = 0.80, 95% confidence interval [CI]: 0.67 to 0.94), but not in overall survival (OS) (HR = 0.89, 95% CI: 0.78 to 1.02). Further sensitivity analysis indicated that adding anti-EGFR MoAbs to FOLFOLX regimen as a first-line treatment showed benefits in both PFS and OS (PFS: HR = 0.74, 95% CI: 0.64 to 0.84; OS: HR = 0.83, 95% CI: 0.73 to 0.95, respectively). Comparing with irinotecan-based chemotherapy or best supportive care, adding anti-EGFR MoAbs revealed an improvement in both PFS (HR = 0.77, 95% CI: 0.69 to 0.86; HR = 0.46, 95% CI: 0.40 to 0.54, respectively) and OS (HR = 0.89, 95% CI: 0.80 to 0.98; HR = 0.65, 95% CI: 0.54 to 0.78, respectively).

CONCLUSION

Anti-EGFR MoAbs as a monotherapy or in combination with either irinotecan-based chemotherapy or FOLFOX in patients with RAS wild-type mCRC have better response and survival outcome, whereas OS does not benefit from adding anti-EGFR MoAbs to another oxaliplatin-based regimen. Anti-EGFR MoAbs have increased the risk of adverse effects than chemotherapy alone. More high-quality randomized controlled trials for RAS wild type are necessary.

Targeting EGFR pathway in metastatic colorectal cancer- tumour heterogeniety and convergent evolution

Despite significant progress in management of metastatic colorectal cancer (mCRC) pertaining to better screening procedures and amelioration of the therapeutic armamentarium with targeted therapies, prognosis remains poor. Targeting epidermal growth factor receptor (EGFR) has been of particular interest owing to favourable efficacy benefits demonstrated by monoclonal antibodies (cetuximab and panitumumab) in various clinical settings and development of predictive biomarkers informing treatment decisions respectively. In spite of optimal patient selection based on RAS mutation status, primary and secondary resistance to monoclonal antibodies is higher than desired. Further research into predictive biomarkers is therefore essential, but has, to date, been conducted with considerable limitations. Whilst molecular heterogeneity has been demonstrated by several studies in mCRC, for incomprehensible reasons, multiple resistant genetic alterations that emerge under the selective pressure of EGFR-targeted therapies are somehow able to influence the biological and clinical behaviour of cancer cells, despite being detectable at extremely low frequencies. Intriguingly, these subclonal events largely seem to converge on RAS/RAF/MAPK pathway in patients treated with EGFR-targeted monoclonal antibodies. This review describes the clinical and biological evolution and development of EGFR targeted therapies in mCRC, the challenges in the presence of molecular complexities, the role of cell free (cf)-DNA and future strategies that could lead to further optimal discovery of clinically meaningful biomarkers and application of precision medicine.

Evaluating the recent developments in palliative chemotherapy for metastatic colorectal cancer

The incidence of colorectal cancer (CRC) has increased. CRC is the third most common cancer and the fourth most common cause of cancer-related deaths in Korea. Palliative chemotherapy can be used to shrink tumors and ease symptoms caused by the cancer when cure is not possible. It is important to identify chemotherapeutic agents that can be used to effectively treat metastatic CRC (mCRC) and thus improve the survival and quality of life of patients with mCRC. This review aimed to evaluate the recent developments in palliative chemotherapy for mCRC and the biological or targeted agents used based on genetic alterations.

Genetics of rectal cancer and novel therapies: primer for radiologists

Rectal cancer accounts for one-third of newly diagnosed colorectal cancer cases. Given its anatomical location and risk for local recurrence, a multidisciplinary treatment program including surgery, radiation therapy, and chemotherapy has demonstrated improved outcomes in localized disease. Genetic analysis has become part of the standard approach for management of advanced disease and new trials are considering tailored therapies for locally advanced disease. This review describes molecular subsets of colorectal cancer; implications for clinical management, including patterns of metastatic spread and response to therapies; and emerging matched therapies. During the last decade, significant biological differences have been noted based on colorectal cancer primary location and here we focus on rectal cancers and relevant markers for this disease. As more treatment for localized rectal cancer is shifted to the neoadjuvant setting and more targeted regimens are developed for metastatic disease, radiologists will increasingly see patients defined by molecular subsets and their awareness of the genetics of rectal cancer will help further refine our understanding of this disease.

Optimizing biologic sequencing in metastatic colorectal cancer: first line and beyond

Significant advances in the treatment of metastatic colorectal cancer (mcrc) since the early 2000s have led to improved clinical outcomes, including overall survival (os). When fluorouracil was the sole treatment agent for mcrc, os in phase iii studies was approximately 12 months. Now, in 2019, the median os (mos) in the most recent mcrc clinical trials has been approaching 3 years. The biologic agents that target the vascular endothelial growth factor (vegf), epithelial growth factor receptor (egfr), human epidermal growth factor receptor 2 (her2), PD-1, ctla-4, ntrk, and braf pathways play important roles in the mcrc treatment algorithm, given their significant-sometimes dramatic-activity. Emerging data indicate that the choice of a specific biologic at a particular time (line of treatment) for specific patient populations (based on tumour characteristics) is critical. In the present review, we discuss the available evidence for optimal biologic sequencing in the management of mcrc.

BRAF-Mutated Colorectal Cancer: Clinical and Molecular Insights

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. It is a heterogeneous disease, which can be classified into different subtypes, characterized by specific molecular and morphological alterations. In this context, BRAF mutations are found in about 10% of CRC patients and define a particular subtype, characterized by a dismal prognosis, with a median survival of less than 12 months. Chemotherapy plus bevacizumab is the current standard therapy in first-line treatment of BRAF-mutated metastatic CRC (mCRC), with triplet (FOLFOXIRI) plus bevacizumab as a valid option in patients with a good performance status. BRAF inhibitors are not so effective as compared to melanoma, because of various resistance mechanisms. However, the recently published results of the BEACON trial will establish a new standard of care in this setting. This review provides insights into the molecular underpinnings underlying the resistance to standard treatment of BRAF-mutated CRCs, with a focus on their molecular heterogeneity and on the research perspectives both from a translational and a clinical point of view.

Precision medicine for metastatic colorectal cancer: an evolving era

Introduction: Metastatic colorectal cancer (CRC) remains a dilemma for cancer researchers with an increasing incidence in the younger patient population. Until the last decade, limited therapeutic options were available for metastatic CRC patients leading to relatively poor clinical outcomes.Areas covered: With advances in genome sequencing technology and reductions in the cost of next-generation sequencing, molecular profiling has become more accessible for cancer researchers and clinical investigators, which has furthered our understanding of the molecular behavior of CRC. This progress has recently translated into significant advances in molecular-based therapeutics and led to the development of new target-specific agents in metastatic CRC patients. In this review article, we extensively elaborate on genomic alterations seen in CRC patients including, but not limited to, EGFR, MMR, BRAF, HER2, NTRKs, FGFR, BRCA1/2, PALB2, POLE, and POLD1 genes, all of which are potentially actionable by either an FDA-approved agent or in a clinical trial setting.Expert opinion: We strongly recommend molecular profiling in metastatic CRC patients during the early course of their disease, as this may provide therapeutic and prognostic information that can guide clinicians to practice precision medicine. Patients with potentially actionable genes should be considered for targeting agents based on molecular alterations.

The Prognostic Impact of KRAS Mutation in Patients Having Curative Resection of Synchronous Colorectal Liver Metastases

BACKGROUND

m-KRAS has been recently reported to be a significant prognostic factor in patients undergoing resection of colorectal liver metastases. This is due to the lack of response to monoclonal epithelial growth factor receptor antibodies, and potentially as a result of a more aggressive tumor biology.

METHODS

The National Cancer Database was queried to identify patients with known KRAS status presenting with colorectal cancer and liver metastases who underwent resection of the primary tumor and metastatic disease between 2010 and 2015.

RESULTS

A total of 2655 patients were identified of which 1116 (42%) had m-KRAS. Tumor size, lymph node involvement rates, and margin status of the primary tumor were similar between patients with m-KRAS and wild-type KRAS (wt-KRAS). In the multivariable analysis, African-American race and right-sided colon cancers were independently associated with m-KRAS (both p < 0.001). m-KRAS patients had a significantly lower overall survival (OS) than those with wt-KRAS, with a 3- and 5-year OS of 51 vs. 64% and 31 vs. 42%, respectively (p < 0.001). After adjustment for available prognostic confounders, factors independently associated with worse OS were increasing age, receipt of monoagent chemotherapy, tumor size, positive lymph node, and resection margin status of the primary tumor, right-sided cancers, and m-KRAS.

CONCLUSIONS

m-KRAS is associated with worse OS in patients presenting with colorectal cancer and liver metastases undergoing resection of the primary tumor and metastatic disease. Right-sided lesions and African-American race were associated with m-KRAS. However, while right-sided remained an independent prognostic factor for OS, race did not.

Metastatic colorectal cancer (mCRC): French intergroup clinical practice guidelines for diagnosis, treatments and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFR)

INTRODUCTION

This document is a summary of the French intergroup guidelines regarding the management of metastatic colorectal cancer (mCRC) published in January 2019, and available on the French Society of Gastroenterology website (SNFGE) (www.tncd.org).

METHODS

This collaborative work was realized by all French medical and surgical societies involved in the management of mCRC. Recommendations are graded in three categories (A, B and C), according to the level of evidence found in the literature, up until December 2018.

RESULTS

The management of metastatic colorectal cancer has become complex because of increasing available medical, radiological and surgical treatments alone or in combination. The therapeutic strategy should be defined before the first-line treatment, mostly depending on the presentation of the disease (resectability of the metastases, symptomatic and/or threatening disease), of the patient's condition (ECOG PS, comorbidities), and tumor biology (RAS, BRAF, MSI). The sequence of targeted therapies also seems to have an impact on the outcome (angiogenesis inhibition beyond progression). Surgical resection of metastases was the only curative intent treatment to date, joined recently by percutaneous tumor ablation tools (radiofrequency, microwave). Localized therapies such as hepatic intra-arterial infusion, radioembolization and hyperthermic intraperitoneal chemotherapy, also have seen their indications specified (liver-dominant disease and resectable peritoneal carcinomatosis). New treatments have been developed in heavily pretreated patients, increasing overall survival and preserving quality of life (regorafenib and trifluridine/tipiracil). Finally, immune checkpoint inhibitors have demonstrated high efficacy in MSI mCRC.

CONCLUSION

French guidelines for mCRC management are put together to help offer the best personalized therapeutic strategy in daily clinical practice, as the mCRC therapeutic landscape is complexifying. These recommendations are permanently being reviewed and updated. Each individual case must be discussed within a multidisciplinary team (MDT).

Dynamic monitoring of HER2 amplification in circulating DNA of patients with metastatic colorectal cancer treated with cetuximab

PURPOSE

Cetuximab (CTX) has been used to treat metastatic colorectal cancer (mCRC) with wild-type (wt) RAS and BRAF genes. Meanwhile HER2 amplification reportedly denoted CTX-resistant mCRC tumors. We investigated whether monitoring of HER2 amplification in circulating DNA allowed early detection of mCRC progression and CTX resistance.

METHODS

mCRC, who progressed after CTX treatments between July 2015 and January 2018.

RESULTS

Of the 36 patients, 5 (13.9%) exhibited dynamic fluctuations of HER2 amplification in plasma in the course of CTX treatment, of whom 2 were positive for HER2 amplification in matched tumor specimens at baseline (per FISH). All 5 primary sites were left side: 3 rectums and 2 descending colon. HER2 ratio fluctuations in circulating DNA not only reflected changes in tumor volume, but their obvious increases presaged CT-documented progress by an average lead time of 2 months. Interestingly, progression-free survival did not significantly differ between these 5 patients and those without HER2 amplification (HR 1.06, 95% CI 0.40-2.77, P = 0.909).

CONCLUSION

Plasma HER2 amplification detected by ddPCR changed over time and predicted resistance to CTX, by an average lead time of 2 months. Further study is needed to validate our findings.

Pre-treatment inflammatory biomarkers predict early treatment response and favorable survival in patients with metastatic colorectal cancer who underwent first line cetuximab plus chemotherapy

Objective

This study was to determine whether peripheral blood biomarkers including neutrophil‑lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and systemic immune inflammation index (SII) could predict early response to cetuximab; moreover, the prognostic ability of those biomarkers on progression free survival (PFS) and overall survival (OS) of metastatic colorectal cancer (mCRC) patients with wild-type (WT) RAS was also investigated.

Methods

mCRC patients with WT RAS treated with cetuximab plus chemotherapy were retrospectively analyzed, and early response was evaluated according to RECIST 1.1 after three or four treatment cycles. In prior to chemotherapy, hematologic data and clinic-pathological parameters were collected. The associations between pre-treatment inflammatory biomarkers and early response, and the prognostic value of those biomarkers were analyzed. A total of 102 patients were enrolled and divided into low or high NLR, PLR, and SII groups, respectively.

Results

The early response rate was significantly higher in the low NLR (p<0.001), low PLR (p=0.045), and low SII (p=0.011), respectively. In multivariate analyses, primary tumor resection (hazard ratio (HR) 0.411, p<0.001), carcino-embryonic antigen ≤5 ng/mL (HR 0.406, p<0.001), early treatment response (HR 0.322, p<0.001), and low NLR (HR 0.665, p=0.031) were independent factors of longer PFS. Primary tumor resection (HR 0.488, p=0.003) and early response (HR 0.392, p<0.001) were independent factors of longer OS. Further analysis showed that patients with early response, even in the high groups, can achieve better PFS and OS than non-responders.

Conclusion

Pre-treatment inflammatory biomarkers, especially NLR were predictors of benefit from cetuximab-combined therapy in mCRC patients. They were also predictors of significantly longer PFS and OS of early responders compared to non-responders.

Impact of Delayed Addition of Anti-EGFR Monoclonal Antibodies on the Outcome of First-Line Therapy in Metastatic Colorectal Cancer Patients: a Retrospective Registry-Based Analysis

BACKGROUND

The addition of monoclonal antibodies targeting the epidermal growth factor receptor (anti-EGFR Abs) to chemotherapy for metastatic colorectal carcinoma (mCRC) is commonly delayed in the real-world clinical practice, usually because of late RAS testing results.

OBJECTIVE

To determine whether delayed addition of anti-EGFR mAbs up to the fourth cycle of backbone chemotherapy adversely affected outcomes of mCRC patients treated with first-line regimens.

PATIENTS AND METHODS

Clinical data of patients with histologically verified, RAS wild-type mCRC treated with first-line systemic therapy regimens containing anti-EGFR mAbs were retrospectively analysed from a national database. Patients were divided into three groups according to the timing of anti-EGFR mAbs addition to the chemotherapy backbone. Cohort A (n = 401) included patients in whom anti-EGFR mAbs were added to chemotherapy from the first cycle, cohort B (n = 71) patients with anti-EGFR mAbs added to chemotherapy from the second cycle, and cohort C (n = 101) patients who had anti-EGFR mAbs added to chemotherapy from the third or fourth cycle.

RESULTS

Three hundred and thirty-six (58.6%) patients received panitumumab and 237 (41.4%) patients received cetuximab. The median progression-free survival (PFS) of the whole cohort was 12.2 months (95% confidence interval [CI] 10.9-13.5), and the median overall survival (OS) was 33.5 months (95% CI 27.6-39.4). The median PFS and OS for patients treated with anti-EGFR mAbs added to chemotherapy were 12.9 (95% CI 11.5-14.3) and 30.6 months (95% CI 25.2-36.1) for cohort A, 9.7 (95% CI 9.1-10.3) and not reached for cohort B, compared to 11.5 (95% CI 9.8-13.2) and 37.9 months (95% CI 28.6-47.3) for cohort C, respectively.

CONCLUSIONS

Delayed addition of anti-EGFR mAbs to first-line chemotherapy was not associated with inferior survival or response rates.

Association of Primary Tumor Site With Mortality in Patients Receiving Bevacizumab and Cetuximab for Metastatic Colorectal Cancer

Importance

Biologic therapy (BT) (eg, bevacizumab or cetuximab) is increasingly used to treat metastatic colorectal cancer (mCRC). Recent investigations have suggested that right- or left-sided primary tumor origin affects survival and response to BT.

Objective

To evaluate the association of tumor origin with mortality in a diverse population-based data set of patients receiving systemic chemotherapy (SC) and bevacizumab or cetuximab for mCRC.

Design, Setting, and Participants

This population-based nonconcurrent cohort study of statewide California Cancer Registry data included all patients aged 40 to 85 years diagnosed with mCRC and treated with SC only or SC plus bevacizumab or cetuximab from January 1, 2004, through December 31, 2014. Patients were stratified by tumor origin in the left vs right sides.

Interventions

Treatment with SC or SC plus bevacizumab or cetuximab.

Main Outcomes and Measures

Mortality hazards by tumor origin (right vs left sides) were assessed for patients receiving SC alone or SC plus bevacizumab or cetuximab. Subgroup analysis for patients with wild-type KRAS tumors was also performed.

Results

A total of 11 905 patients with mCRC (6713 men [56.4%] and 5192 women [43.6%]; mean [SD] age, 60.0 [10.9] years) were eligible for the study. Among these, 4632 patients received SC and BT. Compared with SC alone, SC plus bevacizumab reduced mortality among patients with right- and left-sided mCRC, whereas SC plus cetuximab reduced mortality only among patients with left-sided tumors and was associated with significantly higher mortality for right-sided tumors (hazard ratio [HR], 1.31; 95% CI, 1.14-1.51; P < .001). Among patients treated with SC plus BT, right-sided tumor origin was associated with higher mortality among patients receiving bevacizumab (HR, 1.31; 95% CI, 1.25-1.36; P < .001) and cetuximab (HR, 1.88; 95% CI, 1.68-2.12; P < .001) BT, compared with left-sided tumor origin. In patients with wild-type KRAS tumors (n = 668), cetuximab was associated with reduced mortality among only patients with left-sided mCRC compared with bevacizumab (HR, 0.75; 95% CI, 0.63-0.90; P = .002), whereas patients with right-sided mCRC had more than double the mortality compared with those with left-sided mCRC (HR, 2.44; 95% CI, 1.83-3.25, P < .001).

Conclusions and Relevance

Primary tumor site is associated with response to BT in mCRC. Right-sided primary tumor location is associated with higher mortality regardless of BT type. In patients with wild-type KRAS tumors, treatment with cetuximab benefited only those with left-sided mCRC and was associated with significantly poorer survival among those with right-sided mCRC. Our results underscore the importance of stratification by tumor site for current treatment guidelines and future clinical trials.

Activity and Safety of Cetuximab Plus Modified FOLFOXIRI Followed by Maintenance With Cetuximab or Bevacizumab for RAS and BRAF Wild-type Metastatic Colorectal Cancer: A Randomized Phase 2 Clinical Trial

Importance

The combination of a triple-drug chemotherapy regimen with an anti-epidermal growth factor receptor (EGFR) agent as a first-line treatment of metastatic colorectal cancer (mCRC) showed promising activity along with safety concerns in single-arm phase 2 trials. The role of maintenance following chemotherapy and anti-EGFR and the optimal regimen to be adopted are not established.

Objectives

To evaluate the activity and safety of cetuximab plus modified FOLFOXIRI (mFOLFOXIRI) and explore the role of maintenance with cetuximab or bevacizumab in RAS and BRAF wild-type mCRC.

Design, Setting, and Participants

In a prospective, noncomparative, open-label, multicenter, randomized phase 2 trial, patients aged 18 to 75 years with unresectable, previously untreated RAS and BRAF wild-type (before amendment, KRAS wild-type) mCRC were recruited from 21 oncology units in Italy from October 19, 2011, to March 1, 2015 (followed up through May 31, 2017). In total, 323 patients were screened and 143 were randomized to 2 treatment arms to receive as a first-line induction a regimen of mFOLFOXIRI plus cetuximab followed by cetuximab (arm A) or bevacizumab (arm B) until disease progression. Primary analyses were conducted in a modified intention-to-treat population.

Interventions

mFOLFOXIRI plus cetuximab repeated every 2 weeks for up to 8 cycles, followed by maintenance with cetuximab or bevacizumab until disease progression.

Main Outcomes and Measures

The primary end point was the 10-month progression-free rate (PFR); secondary end points included progression-free and overall survival, response rate, rate of metastases resection, and adverse events.

Results

Of 143 patients randomized, 116 (81.1%) (median [interquartile range (IQR)] age, 59.5 [53-67] years; 34 [29.3%] women) had RAS and BRAF wild-type mCRC. At a median (IQR) follow-up of 44.0 (30.5-52.1) months, 10-month PFRs were 50.8% (90% CI, 39.5%-62.2%) in arm A and 40.4% (90% CI, 29.4%-52.1%) in arm B. The overall response rate was 71.6% (95% CI, 62.4%-79.5%). Main grade 3/4 adverse events were neutropenia (occurring in 36 patients [31%]), diarrhea (in 21 patients [18%]), skin toxic effects (in 18 patients [16%]), asthenia (in 11 patients [9%]), stomatitis (in 7 patients [6%]), and febrile neutropenia (in 3 patients [3%]).

Conclusions and Relevance

Although neither of the 2 arms met the primary end point, the findings indicate that a 4-month induction regimen of mFOLFOXIRI plus cetuximab is feasible and provides relevant activity results, leading to a high surgical resection rate.

Trial Registration

clinicaltrials.gov Identifier: NCT02295930.

Evaluating for Pseudoprogression in Colorectal and Pancreatic Tumors Treated With Immunotherapy

Pseudoprogression has been observed in patients with various tumor types treated with immunotherapy. However, the frequency of pseudoprogression is unknown in gastrointestinal malignancies. Metastatic colorectal cancer (mCRC) and advanced pancreatic ductal adenocarcinoma (PDAC) patients who progressed on treatment with immunotherapy beyond RECIST version 1.1 criteria were analyzed. Degree of progression, tumor markers, time to progression, overall survival, Eastern Cooperative Oncology Group Performance Status (ECOG PS), and costs were analyzed for patients treated beyond progression (TBP) and not treated beyond progression. Fifty-nine of 159 (37%) patients with mCRC or PDAC were TBP (31 mCRC, 28 PDAC). Fifty-four of 59 (92%) patients were microsatellite stable. Zero of these 59 patients with initial treatment beyond progression demonstrated subsequent radiographic tumor shrinkage at a median 42 days from first scan documenting progression. A pseudoprogression rate of >6% could be excluded with 95% confidence. Compared with baseline, median growth on the first and second scan that showed progression was 29.8% and 43%, respectively. In those not treated beyond progression, median growth at first restaging was 31.2%. The trend in change in tumor size positively correlated with the trend in tumor markers in all patients TBP. Fifteen patients (25%) experienced grade 3/4 adverse events by continuing treatment beyond progression, whereas 19 (32%) experienced deterioration in ECOG PS. Pseudoprogression was not seen in microsatellite stable patients with mCRC or PDAC treated with immunotherapy. Changes in tumor markers correlated with changes in tumor volume. This data may help inform future treatment decisions and/or trial design in patients with mCRC or advanced PDAC treated with immunotherapy.

Current Development of Monoclonal Antibodies in Cancer Therapy

Exploiting the unique specificity of monoclonal antibodies has revolutionized the treatment and diagnosis of haematological and solid organ malignancies; bringing benefit to millions of patients over the past decades. Recent achievements include conjugating antibodies with toxic payloads resulting in superior efficacy and/or reduced toxicity, development of molecular imaging techniques targeting specific antigens for use as predictive and prognostic biomarkers, the development of novel bi- and tri-specific antibodies to enhance therapeutic benefit and abrogate resistance and the success of immunotherapy agents. In this chapter, we review an overview of antibody structure and function relevant to cancer therapy and provide an overview of pivotal clinical trials which have led to regulatory approval of monoclonal antibodies in cancer treatment. We further discuss resistance mechanisms and the unique side effects of each class of antibody and provide an overview of emerging therapeutic agents.

Towards Circulating-Tumor DNA-Based Precision Medicine

In the era of precision medicine, targeted therapies have been implemented for various diseases. Genomic information guides decision-making in cancer treatment. The improvements in next-generation sequencing and polymerase chain reaction have made it possible to access the genetic information using circulating-tumor DNAs (ctDNAs). Molecular characteristics of individual tumors can be obtained by analysis of ctDNAs, thus making them excellent tools to guide decision-making during treatment. In oncology, the use of ctDNAs in clinical practice is now gaining importance. Molecular analysis of ctDNAs has potential for multiple clinical applications, including early diagnosis, prognosis of disease, prognostic and/or predictive biomarkers, and monitoring response to therapy and clonal evolution. In this paper, we highlight the applications of ctDNAs in cancer management, especially in metastatic setting, and summarize recent studies about the use of ctDNAs as predictive biomarkers for the therapeutic adaptation/response in lung cancer, breast cancer, and colorectal cancer. These studies offer the evidence to use ctDNAs as a promising approach to solve unmet clinical needs.

Exploring the best treatment options for BRAF-mutant metastatic colon cancer

The BRAFV600E mutation is a well-accepted poor prognostic factor in patients with metastatic colorectal cancer (mCRC), as it confers Ras-independent stimulation of the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway involved in proliferation, migration, angiogenesis and the suppression of apoptosis. Analysis of the potential predictive value of BRAF for treatment efficacy is inherently confounded by this known prognostic impact. Currently, approved therapeutic strategies for patients with BRAF-mutant (BRAF-mt) mCRC are suboptimal, and uncertainty exists regarding how to best treat these patients. Based on the available evidence, it is currently not possible to confirm the superiority of any available treatment options cited in European Society for Medical Oncology and National Comprehensive Cancer Network guidelines (that is, doublet or triplet chemotherapy regimens plus anti-vascular endothelial growth factor or anti-epidermal growth factor receptors), even if triplet chemotherapy plus bevacizumab is the most accepted standard regimen. In this review, we highlight still-emerging strategies that could be deployed to combat BRAF-mt mCRC, including triplet chemotherapy plus available biologic agents, rationally derived combinations of targeted agents and immunotherapy. While it is clear that the needs of patients with BRAF-mt mCRC are currently unmet, we are cautiously optimistic that the recently renewed research interest in these patients will yield clinically relevant insights and therapeutic strategies.

KRAS Status as a Predictor of Chemotherapy Activity in Patients With Metastatic Colorectal Cancer

BACKGROUND

KRAS mutations occur in 40% of colorectal cancers (CRCs), affecting the efficacy of agents targeting the epidermal growth factor receptor. However, the effect of KRAS mutation status on the activity of non-epidermal growth factor receptor-targeting chemotherapy has not been fully elucidated. The aim of the present study is to evaluate the effect of KRAS status on the activity of different chemotherapeutic regimens.

PATIENTS AND METHODS

A retrospective chart review of chemotherapy-treated patients with metastatic CRC with known KRAS status was undertaken. Chemotherapy effects were measured by progression-free survival, time to chemotherapy resistance, and overall survival. Analysis was performed for the different chemotherapy regimens, and according to the KRAS mutation status while adjusting for potential confounders.

RESULTS

KRAS mutations were detected in 43% of 223 patients with metastatic CRC who were treated at the Ottawa Hospital. The baseline distribution of KRAS wild-type (WT) and mutant status was similar. The median follow-up was 27.2 months. Regimens received included single agents or combinations of 2 or 3 chemotherapies. Among those treated with capecitabine-based regimens, survival was longer for patients with KRAS WT status (hazard ratio, 0.47; 95% confidence interval, 0.23-0.95; P < .0001) when compared with those with mutant status. The median overall survival was 46.7 versus 32.6 months for patients with KRAS WT versus mutant status, respectively. The time to chemotherapy resistance was also significantly longer for patients with WT status (hazard ratio, 0.49; 95% confidence interval, 0.25-0.97; P = .0398). A trend for progression-free survival did not reach statistical significance.

CONCLUSION

Patients with KRAS WT tumors may benefit more from capecitabine-based treatments than patients with mutant status. Further research is needed to explain this data.

Silencing Smad4 attenuates sensitivity of colorectal cancer cells to cetuximab by promoting epithelial‑mesenchymal transition

The aberrant expression of tumor suppressor Smad4 often occurs in colorectal cancer (CRC), and this phenomenon is believed to be associated with drug resistance. The present study aimed to investigate the effects of Smad4 on the sensitivity of CRC cells to cetuximab, and the possible mechanism underlying such an effect. A total of 629 colorectal adenocarcinoma cases were downloaded from The Cancer Genome Atlas (TCGA) database, and a Smad4 mutation rate of ~21% was demonstrated among the cases. Low expression of Smad4 was present in CRC tissues analyzed by TCGA and in four CRC cell lines, as determined by reverse transcription‑quantitative PCR (RT‑qPCR) and western blot analysis. Cell Counting kit‑8 (CCK‑8) was used to measure the effects of different concentrations of cetuximab on SW480 cell viability at 24 and 48 h. The results demonstrated that treatment of SW480 cells with 20 µg/ml cetuximab for 48 h markedly reduced cell viability. In addition, plasmids were transfected into SW480 cells to induce Smad4 silencing or overexpression. Silencing Smad4 attenuated the sensitivity of SW480 CRC cells to cetuximab; this effect was reflected in increased cell viability and slightly increased migration and invasion, as determined by CCK‑8, wound scratch and Transwell analyses. RT‑qPCR and western blotting was performed to assess the expression levels of apoptosis‑ and epithelial‑mesenchymal transition (EMT)‑related genes. Silencing Smad4 partly reversed the effects of cetuximab on the mRNA and protein expression levels of vimentin, Bax/Bcl‑2 and E‑cadherin. However, Smad4 overexpression enhanced SW480 cell sensitivity to cetuximab. In conclusion, Smad4 may serve a vital role in the sensitivity of CRC cells to chemotherapeutic drugs by promoting EMT.

Risk factors and prognostic significance of lateral pelvic lymph node metastasis in advanced rectal cancer

BACKGROUND

The aim of this study was to elucidate the risk factors for and prognostic value of lateral pelvic lymph node (LPLN) metastasis in advanced rectal cancer patients, including those with stage IV disease.

METHODS

The treatment outcomes of 78 patients with advanced rectal cancer, the lower margin of which was located at or below the peritoneal reflection, who underwent curative-intent surgery with bilateral LPLN dissection from 2005 to 2018 were retrospectively analyzed.

RESULTS

In total, 78 rectal cancer patients, including 13 patients with stage IV tumors, 9 patients (11.5%) had LPLN metastasis. A multivariate analysis to identify preoperative clinical factors associated with LPLN metastasis showed that tumor location (below the peritoneal reflection: Rb), LPLN metastasis on preoperative imaging and distant metastasis were independent predictors of LPLN metastasis. In addition, metastasis at the regional lymph nodes in the mesorectum was significantly associated with LPLN metastasis. Both the disease-free survival (DFS) and cancer-specific survival (CSS) of patients with LPLN metastasis were significantly worse in comparison to patients without LPLN metastasis, and the CSS of stage IV patients with LPLN metastasis was significantly worse in comparison to stage IV patients without LPLN metastasis.

CONCLUSIONS

Tumor location (Rb), LPLN metastasis on preoperative imaging and distant metastasis were risk factors for LPLN metastasis. The prognosis of rectal cancer patients with LPLN metastasis is poor. There may not be the indication of LPLN dissection in stage IV lower rectal cancer except cases having complaints due to LPLN metastasis.

Cardiovascular complications of metastatic colorectal cancer treatment

Colorectal cancer (CRC) is the third most common malignancy in men and the second in women and the fourth cause of cancer death. Survival rates decrease greatly according to the stage of the disease at the time of diagnosis. Approximately 50% of CRC patients will develop metastatic disease (mCRC) with survival and prognosis depending on the timing of metastatic development, and the localization and number of metastatic sites. The overall survival of patients with mCRC has been significantly improved over the last years from approximately 12 to more than 30 months with the integration of multiple cytotoxic agents and targeted therapies. The optimal therapeutic strategy depends on the general condition and performance status of the patient, the resectability or not of metastases and the mutational status of the tumor in terms of BRAF and RAS. Cardiovascular (CV) complications of mCRC treatment may develop peri-operatively and mostly during chemotherapy. During first-line treatment, 90% of patients experience more than one adverse event (AE) and 39% of them are CV. Angina, hypertension, arrhythmias, arterial and venous thrombotic events (VTEs), heart failure (HF) and death are the main CV events resulting from the applied chemotherapy regimens. Cardio-oncology consultation for identification of high-risk patients, proper monitoring during and after therapy and timely intervention would allow the successful prevention and the efficient management of cardiotoxicity, rendering the patient able to receive the indicated cancer therapy and improving the overall outcome.

Impact of circulating tumor DNA mutant allele fraction on prognosis in RAS-mutant metastatic colorectal cancer

Despite major advances in the treatment of metastatic colorectal cancer (mCRC), the survival rate remains very poor. This study aims at exploring the prognostic value of RAS-mutant allele fraction (MAF) in plasma in mCRC. Forty-seven plasma samples from 37 RAS-mutated patients with nonresectable metastases were tested for RAS in circulating tumor DNA using BEAMing before first- and/or second-line treatment. RAS MAF was correlated with several clinical parameters (number of metastatic sites, hepatic volume, carcinoembryonic antigen, CA19-9 levels, primary site location, and treatment line) and clinical outcome [progression-free survival (PFS) and overall survival (OS)]. An independent cohort of 32 patients from the CAPRI-GOIM trial was assessed for clinical outcome based on plasma baseline MAF. RAS MAF analysis at baseline revealed a significant correlation with longer OS [Hazard ratios (HR) = 3.514; P = 0.00066]. Patients with lower MAF also showed a tendency to longer PFS, although not statistically significant. Multivariate analysis showed RAS MAFs as an independent prognostic factor in both OS (HR = 2.73; P = 0.006) and first-line PFS (HR = 3.74; P = 0.049). Tumor response to treatment in patients with higher MAF was progression disease (P = 0.007). Patients with low MAFs at baseline in the CAPRI-GOIM group also showed better OS [HR = 3.84; 95% confidence intervals (CI) 1.5-9.6; P = 0.004] and better PFS (HR = 2.5; 95% CI: 1.07-5.62; P = 0.033). This minimally invasive test may help in adding an independent factor to better estimate outcomes before initiating treatment. Further prospective studies using MAF as a stratification factor could further validate its utility in clinical practice.

Immunotherapies and Targeted Therapies in the Treatment of Metastatic Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer deaths, and while mortality has largely improved in the developed world, five-year survival for metastatic disease remains dismally low at only 15%. Fortunately, nearly a dozen targeted therapies and immunotherapies have been FDA approved in the past decade for certain patient profiles with metastatic CRC (mCRC), and many others are under development. Checkpoint inhibitors such as pembrolizumab have proven effective at extending survival for mismatch repair (MMR)-deficient and high microsatellite instability (MSI) mCRC patients. In combination with chemotherapy in first- and second-line treatment, antiangiogenic (anti-vascular endothelial growth factor (anti-VGEF)) agent bevacizumab has been shown to increase mCRC survival. Anti-epidermal growth factor receptor (anti-EGFR) agents panitumumab and cetuximab, in combination with chemotherapy, have also prolonged survival among KRAS and all RAS wild-type mCRC patients. Among these patients, anti-EGFR therapy has been found to be more efficacious than bevacizumab. Improved selectivity has allowed small-molecule receptor tyrosine kinase (RTK) inhibitors to target VEGF and EGFR with greater efficacy and tolerability. Combinations of immunotherapies, RTKs, monoclonal antibodies, and cytotoxic drugs are being investigated to provide broad-spectrum protection against relapse by simultaneously targeting many cancer hallmarks. Lastly, human epidermal growth factor receptor 2 (HER2) therapy has shown promise for HER2-positive mCRC patients, though larger clinical trials are required to secure FDA approval.

Multidisciplinary management of liver metastases in patients with colorectal cancer: a consensus of SEOM, AEC, SEOR, SERVEI, and SEMNIM

Colorectal cancer (CRC) has the second-highest tumor incidence and is a leading cause of death by cancer. Nearly 20% of patients with CRC will have metastases at the time of diagnosis, and more than 50% of patients with CRC develop metastatic disease during the course of their disease. A group of experts from the Spanish Society of Medical Oncology, the Spanish Association of Surgeons, the Spanish Society of Radiation Oncology, the Spanish Society of Vascular and Interventional Radiology, and the Spanish Society of Nuclear Medicine and Molecular Imaging met to discuss and provide a multidisciplinary consensus on the management of liver metastases in patients with CRC. The group defined the different scenarios in which the disease can present: fit or unfit patients with resectable liver metastases, patients with potential resectable liver metastases, and patients with unresectable liver metastases. Within each scenario, the different strategies and therapeutic approaches are discussed.

Analysis of response-related endpoints in trials of first-line medical treatment of metastatic colorectal cancer

BACKGROUND

Tumor radiologic response after systemic chemotherapy has been used as endpoint of trials of patients with metastatic colorectal cancer (mCRC), which can report the best overall response rate (ORR) and the disease control rate (DCR) by RECIST criteria as well as the early tumor shrinkage (ETS). The present study perform a trial-level analysis to verify whether such response-related endpoints are predictive of overall survival (OS).

METHODS

After a systematic search, randomized clinical trials (RCTs) were selected each time they evaluated the three response endpoints and progression-free survival (PFS). Two arms per trial were selected, and the correlation between the difference in each endpoint and the difference in OS was calculated. The analysis then evaluated the effects of treatment on ∆ORR, or ∆DCR, ∆ETS, ∆PFS, and on ∆OS, using separate linear regressions for each of them, and the proportion of variability explained (R²_trial) on OS for each of the four endpoints was calculated.

RESULTS

The systematic review of the literature led to the selection of 12 RCTs, 7 phase-3 and 5 phase-2. ETS reported a different performance in the entire sample compared to phase-3 trials (R²_trial = 0.172 vs. 0.842), differently from DCR (R²_trial = 0.541 vs. 0.816) and ORR (R²_trial = 0.349 vs. 0.740). Surprisingly, PFS predicted OS with a weak correlation, which was not significant in the subgroup of phase-3 studies (R²_trial = 0.455 vs. 0.466).

CONCLUSION

The results of the present trial-level analysis report a good performance of two response-related endpoints, DCR and ETS, and suggest that they could be differently used depending on the setting of disease and the type of medical treatment.

Impact of Variability in Portal Venous Phase Acquisition Timing in Tumor Density Measurement and Treatment Response Assessment: Metastatic Colorectal Cancer as a Paradigm

PURPOSE

New response patterns to anticancer drugs have led tumor size-based response criteria to shift to also include density measurements. Choi criteria, for instance, categorize antiangiogenic therapy response as a decrease in tumor density > 15% at the portal venous phase (PVP). We studied the effect that PVP timing has on measurement of the density of liver metastases (LM) from colorectal cancer (CRC).

METHODS

Pretreatment PVP computed tomography images from 291 patients with LM-CRC from the CRYSTAL trial (Cetuximab Combined With Irinotecan in First-Line Therapy for Metastatic Colorectal Cancer; ClinicalTrials.gov identifier: NCT00154102) were included. Four radiologists independently scored the scans' timing according to a three-point scoring system: early, optimal, late PVP. Using this, we developed, by machine learning, a proprietary computer-aided quality-control algorithm to grade PVP timing. The reference standard was a computer-refined consensus. For each patient, we contoured target liver lesions and calculated their mean density.

RESULTS

Contrast-product administration data were not recorded in the digital imaging and communications in medicine headers for injection volume (94%), type (93%), and route (76%). The PVP timing was early, optimal, and late in 52, 194, and 45 patients, respectively. The mean (95% CI) accuracy of the radiologists for detection of optimal PVP timing was 81.7% (78.3 to 85.2) and was outperformed by the 88.6% (84.8 to 92.4) computer accuracy. The mean ± standard deviation of LM-CRC density was 68 ± 15 Hounsfield units (HU) overall and 59.5 ± 14.9 HU, 71.4 ± 14.1 HU, 62.4 ± 12.5 HU at early, optimal, and late PVP timing, respectively. LM-CRC density was thus decreased at nonoptimal PVP timing by 14.8%: 16.7% at early PVP ( P < .001) and 12.6% at late PVP ( P < .001).

CONCLUSION

Nonoptimal PVP timing should be identified because it significantly decreased tumor density by 14.8%. Our computer-aided quality-control system outperformed the accuracy, reproducibility, and speed of radiologists' visual scoring. PVP-timing scoring could improve the extraction of tumor quantitative imaging biomarkers and the monitoring of anticancer therapy efficacy at the patient and clinical trial levels.

Chemotherapy, Still an Option in the Twenty-First Century in Metastatic Colorectal Cancer?

Substantial improvements have been made in the systemic treatment of colorectal cancer over the last two decades. Median overall survival (OS) of patients with metastatic colorectal cancer (mCRC) has been constantly increased and the most recent first-line studies exceeded the 30-month median overall survival. The standard first-line regimen for mCRC is a combination of chemotherapy plus a biological agent either targeting the main angiogenic growth factor vascular endothelial growth factor (VEGF) via Bevacizumab or by antibodies targeting the epidermal growth factor receptor (EGRF) via Panitumumab or Cetuximab. Recent improvements have been shown in the efficacy of the biological agent by stratifying these agents according to the primary tumor location. In this context EGFR-inhibitors showed improved OS when used first-line in tumors derived from the left-sided colon or rectum, while tumor sidedness was not predictive for anti-VEGF-antibodies. Furthermore, the biological activity of anti-EGFR antibodies is restricted to tumors with a rat sarcoma virus (RAS)-wild-type genotype but not RAS-mutated tumors. The RAS-mutation status is not predictive for VEGF-inhibitors. Recent developments in the molecular characterisation of tumor cells led to the development of specific so called targeted therapies in colorectal cancer.

The current state of molecular testing in the treatment of patients with solid tumors, 2019

The world of molecular profiling has undergone revolutionary changes over the last few years as knowledge, technology, and even standard clinical practice have evolved. Broad molecular profiling is now nearly essential for all patients with metastatic solid tumors. New agents have been approved based on molecular testing instead of tumor site of origin. Molecular profiling methodologies have likewise changed such that tests that were performed on patients a few years ago are no longer complete and possibly inaccurate today. As with all rapid change, medical providers can quickly fall behind or struggle to find up-to-date sources to ensure he or she provides optimum care. In this review, the authors provide the current state of the art for molecular profiling/precision medicine, practice standards, and a view into the future ahead.

Durable complete response in a patient with metastatic left-sided colon cancer treated with 5-fluorouracil, folinic acid, and irinotecan (FOLFIRI) and panitumumab: A case report

There are rare patients with metastatic colon cancer who experience dramatic and durable responses. Primary tumor location is a prognostic and potentially predictive factor and should be taken into consideration when deciding on the optimal first-line therapy to be used in combination with chemotherapy.

Development and validation of a novel prognostic score to predict survival in patients with metastatic colorectal cancer: the metastatic colorectal cancer score (mCCS)

AIM

Published prognostic scores for metastatic colorectal cancer (mCRC) are based on data from highly selected patient subgroups with specified first-line treatments and may not be applicable to routine practice. We have therefore developed and validated the metastatic colorectal cancer score (mCCS) to predict overall survival (OS) for patients with mCRC.

METHOD

A total of 1704 patients from the prospective, multicentre cohort study Tumour Registry Colorectal Cancer were separated into learning (n = 796) and validation (n = 908) samples. Using a multivariate Cox regression model, the six-factor mCCS was established.

RESULTS

The six independent prognostic factors for survival are as follows: two or more metastatic sites at the start of first-line treatment, tumour grading ≥ G3 at primary diagnosis, residual tumour classification ≥ R1/unknown, lymph node ratio (of primary tumour) ≥ 0.4, tumour stage ≥ III/unknown at primary diagnosis and KRAS status mutated/unknown. The mCCS clearly separated the learning sample into three risk groups: zero to two factors (low risk), three factors (intermediate risk) and four to six factors (high risk). The prognostic performance of the mCCS was confirmed in the validation sample and additionally stratified a large sample of patients with known (K)RAS mutation status.

CONCLUSION

The novel prognostic score, mCCS, clearly defines three prognostic groups for OS at start of first-line therapy. For oncologists, the mCCS represents a simple and easy-to-apply tool for routine clinical use, as it is based on objective tumour characteristics and can assist with treatment decision-making and communication of the prognosis to patients.