Mind the target: human epidermal growth factor receptor 2 in colorectal cancer.

PURPOSE OF REVIEW: In this article, we briefly summarise the current knowledge about human epidermal growth factor receptor 2 (HER2) alterations in colorectal cancer (CRC) and provide an overview of the latest published evidence especially regarding standardisation of detection methods/diagnostic criteria, prognostication, prediction and targeted treatments. RECENT FINDINGS: Over the last 18 months, the results of many studies have been presented confirming the therapeutic potential of established anti-HER2 agents either as a monotherapy or in combination, as well as new anti-HER2 agents like antibody-drug-conjugates and tyrosine kinase inhibitors. Also, we have seen confirmation of the utility of liquid biopsy and ctDNA analyses as tool for HER2 detection and patient selection. SUMMARY: Despite concerning only 5% of metastatic CRC, HER2 represents a valuable target for emerging anti-HER2 therapies that might significantly improve the outcome of these patients. Standardising HER2 detection methods/diagnostic criteria, and producing high-quality, randomised evidence are the next challenges to meet the standards of regulatory authorities and ultimately have anti-HER2 agents available for use in routine practice.

Circulating DNA in the neoadjuvant setting of early stage colon cancer.

BACKGROUND: While circulating tumour (ct)DNA is an indicator of minimal residual disease and negative prognostic factor in stage II-III colon cancer, no study has ever analysed the value of this biomarker in colon cancer patients treated with neoadjuvant chemotherapy. We sought to fill this gap by using prospectively collected plasma samples from 80 stage III colon cancer patients, receiving one cycle of neoadjuvant FOLFOX followed by surgery +/- adjuvant FOLFOX in the PePiTA trial. MATERIAL AND METHODS: Samples were collected at baseline, 2 weeks and surgery. NPY and WIF1 were selected as universal methylation markers for ctDNA, and analysed with ddPCR technology. ROC curves were applied for cut-off points, and outcome measures included 5-year disease-free survival (DFS) and 6-year overall survival (OS). RESULTS: After a median follow-up of 52.5 months, baseline circulating-free (cf) DNA was an independent prognostic factor for DFS (HR 3.35, 95% CI: 1.15-9.77, p = .03), and a trend towards a similar association was observed for relative cfDNA changes between baseline and surgery (HR 2.57, 95% CI: 0.94-7.05, p = .07). Among 60 ctDNA assessable patients, 25 (42%) had detectable ctDNA at baseline. While detection of ctDNA at any pre-operative timepoint was not associated with outcome, patients with ctDNA increase (change of the worst trending methylation marker ≥11%, or mean ctDNA change of NPY and WIF1 ≥ 0%) between baseline and surgery showed a trend towards worse 5-year DFS (HR 3.66, 95% CI: 0.81-16.44, p = .09). CONCLUSION: This is the first study of ctDNA in the neoadjuvant setting of early-stage colon cancer. Results are hypothesis-generating and should be confirmed in larger series.

Anal squamous cell carcinoma: standards of care, new data and ongoing clinical trials.

PURPOSE OF REVIEW: To summarize current standards of care, discuss results of recent studies and present ongoing clinical trials for anal squamous cell carcinoma (ASCC). RECENT FINDINGS: Over the last year, no practice changing studies have been reported in the setting of localised ASCC. A number of retrospective analyses, however, have provided practice-informing data, such as those confirming the negative impact of low compliance to chemoradiotherapy (CRT) on patient outcomes. In contrast, and for the first time, randomized evidence has become available to inform the management of advanced tumours. The InterAACT trial represents a key milestone in the evidence-building process for this disease, establishing carboplatin plus paclitaxel as a new standard of care for treatment-naïve advanced ASCC patients. Furthermore, more data have accumulated about the value of triplet chemotherapy in the first-line setting and of immune checkpoint inhibitors (either as single agents or in combination with other agents) in the refractory setting. SUMMARY: Recent findings have the potential to improve the treatment quality standards and overall outcome of patients with either localised or advanced ASCC. Results from ongoing clinical trials will hopefully provide useful insights into the management of this disease and further shape current treatment paradigms.

Predictive Impact of Mucinous Tumors on the Clinical Outcome in Patients with Poorly Differentiated, Stage II Colon Cancer: A TOSCA Subgroup Analysis.

BACKGROUND: Although American Society of Clinical Oncology and European Society for Medical Oncology guidelines have identified the negative prognostic factors that clinicians have to consider when treating their patients with stage II colon cancer (CC), the role of histological subtype is controversial. SUBJECTS, MATERIALS, AND METHODS: The randomized, multicenter, phase III TOSCA trial compared 3 versus 6 months of fluoropyrimidine-oxaliplatin adjuvant chemotherapy in 3,759 patients with high-risk stage II or stage III CC. The objective of this substudy was to evaluate the influence of histological subtypes on the impact of the treatment duration of adjuvant chemotherapy in terms of relapse-free survival (RFS) and overall survival (OS) in 85 mucinous adenocarcinoma (MUC) and 389 nonmucinous adenocarcinoma (NMUC) patients with high-risk stage II, grade 3 CC. RESULTS: A significant interaction between treatment duration and histology was observed in both RFS (p = .027) and OS (p = .017). In the subgroup of patients with MUC, worse RFS (adjusted hazard ratio [HR], 3.95; 95% confidence interval [CI], 1.03-15.17; p = .045) and OS (HR, 9.56; 95% CI, 1.14-79.98; p = .037) were detected for patients treated in the 3-month arm. No statistically significant differences were found in the subgroup of patients with NMUC. CONCLUSION: Patients with MUC, grade 3, stage II CC require special attention and may need 6 months of oxaliplatin-based chemotherapy. Larger studies are required to assess the combined use of histology and other prognostic/predictive factors to define the administration of chemotherapy in patients with stage II CC and to improve their prognosis. IMPLICATIONS FOR PRACTICE: Although ASCO and ESMO guidelines define the prognostic factors for patients with stage II colon cancer to establish the use of adjuvant chemotherapy, the influence of histological subtypes is controversial in this population. This study underscores that patients with grade 3 mucinous adenocarcinomas may need adjuvant chemotherapy with oxaliplatin and fluoropyrimidines for a duration of 6 months rather than 3 months.

Feasibility and clinical impact of routine molecular testing of gastrointestinal cancers at a tertiary centre with a multi-gene, tumor-agnostic, next generation sequencing panel.

BACKGROUND: High-throughput sequencing technologies are increasingly used in research but limited data are available on the feasibility and value of these when routinely adopted in clinical practice. MATERIAL AND METHODS: We analyzed all consecutive cancer patients for whom genomic testing by a 48-gene next-generation sequencing (NGS) panel (Truseq Amplicon Cancer Panel, Illumina) was requested as part of standard care in one of the largest Belgian cancer networks between 2014 and 2019. Feasibility of NGS was assessed in all study patients, while the impact of NGS on the decision making was analyzed in the group of gastrointestinal cancer patients. RESULTS: Tumor samples from 1064 patients with varying tumor types were tested, the number of NGS requests increasing over time (p < .0001). Success rate and median turnaround time were 91.4% and 12.5 days, respectively, both significantly decreasing over time (p ≤ .0002). Non-surgical sampling procedure (OR 7.97, p < .0001), tissue from metastatic site (OR 2.35, p = .0006) and more recent year of testing (OR 1.79, p = .0258) were independently associated with NGS failure. Excluding well-known actionable or clinically relevant mutations which are recommended by international guidelines and commonly tested by targeted sequencing, 57/279 (20.4%) assessable gastrointestinal cancer patients were found to have tumors harboring at least one actionable altered gene according to the OncoKB database. NGS results, however, had a direct impact on management decisions by the treating physician in only 3 cases (1.1%). CONCLUSIONS: Our findings confirm that NGS is feasible in the clinical setting with acceptably low failure rates and rapid turnaround time. In gastrointestinal cancers, however, NGS-based multiple-gene testing adds very little to standard targeted sequencing, and in routine practice the clinical impact of NGS panels including genes which are not routinely recommended by international guidelines remains limited.

The Optimal Duration of Adjuvant Therapy for Stage III Colon Cancer: the European Perspective.

OPINION STATEMENT: The International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration was created to pool data from different studies worldwide in order to assess whether a shorter duration of adjuvant treatment in colon cancer could maintain the expected benefit while reducing toxicity. The results of the IDEA trials were clinically relevant. They confirmed a two- to sixfold reduction in neurotoxicity for the shorter duration across trials. Overall, the 3-year disease-free survival was very similar: only 0.9% lower for the 3 months group. However, the results were partially unexpected, because they revealed a difference among chemotherapy regimens (CAPOX better than FOLFOX) and risk groups within stage III. The similar outcome between 3 and 6 months of CAPOX coupled with the substantial reduction in toxicity makes us use the CAPOX regimen for 3 months for most stage III patients. An exception to this general rule is the patient with very high risk, i.e., either T4N1b-T4anyN2 or anyTN2b where we use 6 months of CAPOX. Our take from the trial results is also that FOLFOX should never be given for 3 months and preferably not used at all in the adjuvant setting. The conduction of the IDEA enterprise was truly global. The European contribution was major with three fourths of patients enrolled in the four European trials. Herein, we review the results of the "3 versus 6" trials and the literature regarding the interpretation of the collected data in Europe and in the rest of the world.

Platinum salts in advanced breast cancer: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: The interest in platinum salts in breast cancer (BC) therapy has been recently renewed as inhibition of DNA damage response may enhance the effects of DNA-damaging agents in BC tumors with high genomic instability. The present systematic review and meta-analysis of randomized trials were performed to assess the efficacy and safety of therapy with platinum salts in patients with locally advanced or metastatic (hereinafter advanced) BC. METHODS: We searched PubMed, EMBASE, SCOPUS, Web of Science, the Cochrane Library, and CINAHL for phase II/III clinical trials that assessed efficacy of platinum-based therapy in patients with advanced BC. Pooled estimates of overall response rate (RR), median progression-free survival (PFS) and overall survival (OS) were computed using random or fixed effects models. RESULTS: Data on 4625 patients from 23 phase II and III trials (11 with cisplatin, 11 with carboplatin, and 1 with either agents respectively) were analyzed. Estimates for RR, PFS, and OS were obtained from 23, 13, and 15 studies, respectively. Although at the cost of significantly increased fatigue, hematological and gastrointestinal toxicity, compared with non-platinum schemas, cisplatin, and carboplatin prolonged OS (HR 0.91; 95 % CI 0.83-1.00, p = 0.04), PFS (HR 0.84; 95 % CI 0.73-0.97, p = 0.01), and RR (HR 1.27; 95 % CI 1.03-1.57, p = 0.03). CONCLUSIONS: Despite some limitations of the studies examined, including partial information on hormonal receptor and HER2 status, the use of platinum salts significantly prolonged OS, and PFS of patients with advanced BC with no unexpected toxicity.

Streamlining the diagnostic pathway for Lynch syndrome in colorectal cancer patients: a 10-year experience in a single Italian Cancer Center.

BACKGROUND: Universal screening of colorectal cancer (CRC) patients for Lynch syndrome (LS) through MisMatch Repair (MMR) testing is recommended. BRAF V600E mutation and/or MLH1 promoter methylation (Reflex Testing, RefT)generally rule out LS in MLH1-deficient (dMLH1) patients. We estimated the impact of RefTon genetic counseling (GC) and on the diagnostic yield of genetic testing (GT). METHODS: Overall, 3199 CRC patients were referred to our center between 2011 and 2021. Patients referred until January 2019 (n=2536) underwent universal MMR testing and were termed 'Cohort A'; among patients after February 2019 (n=663), 'Cohort B', RefT was also performed in dMLH1 patients. RESULTS: Overall, 401/3199 patients (12.5%) were MMR-deficient (dMMR); 312 (77.8%) in cohort A and 89 (22.2%) inB; 346/401 were dMLH1 (86.3%), 262/312 (83.9%) in cohort A and 84/89 (94.3%) in B. In Cohort A, 91/312 (29.1%) dMMR patients were referred to GC, 69/91 (75.8%) were in the dMLH1 group; 57/69 (82.6%) dMLH1 patients underwent GT and 1/57 (1.7%) had LS. In Cohort B, 3/84 dMLH1 patients did not undergo BRAF testing. Three BRAF wt and not hypermethylated of the remaining 81 dMLH1 patients were referred to GC and GT, and one had LS. This diagnostic pathway reduced GC referrals by 96% (78/81) in Cohort B and increased the diagnostic yield of GT by about 20 times. CONCLUSION: Our findings support RefT in dMLH1 CRC patients within the LS diagnostic pathway, as it reduces the number of GC sessions needed and increases the diagnostic yield of GT.

PD-L1 Expression in Paired Samples of Rectal Cancer.

Immune checkpoint inhibitors and immune-related biomarkers are increasingly investigated in rectal cancer (RC). We retrospectively analysed PD-L1 expression in diagnostic biopsy and resection samples from RC patients treated at our centre between 2000 and 2020. PD-L1 immunostaining (22C3 clone) was evaluated according to tumour proportion (TPS), immune cell (ICS), and the combined positive score (CPS). Eighty-three patients were included. At diagnosis, PD-L1 expression ≥1%/≥5% was observed in 15.4%/0%, 80.7%/37.4%, and 69.2%/25.6% of patients based on TPS, ICS, and CPS, respectively. At surgery, the respective figures were 4.6%/1.5%, 60.2%/32.5%, and 50.7%/26.2%. Using the 1% cut-off and regardless of the scoring system, PD-L1 was less expressed in surgery than biopsy samples (p ≤ 0.04). In paired specimens, PD-L1-ICS reduction was especially observed following neoadjuvant long-course (chemo)radiotherapy (p = 0.03). PD-L1-ICS of ≥5% in surgical samples (HR: 0.17; p = 0.02), and a biopsy-to-surgery increase in PD-L1-ICS (HR: 0.19; p = 0.04) was predictive for longer disease-free survival, while the PD-L1-ICS of either ≥1% (HR 0.28; p = 0.04) or ≥5% (HR 0.19; p = 0.03) in surgical samples and the biopsy-to-surgery increase in PD-L1-ICS (HR: 0.20; p = 0.04) were associated with better overall survival. Our study suggests that PD-L1 expression in RC is largely reflective of immune cell infiltration, and its presence/increase in surgical samples predicts better outcomes.

Rationale and Design of the COPERNIC Trial: A Study of On-treatment ctDNA Changes in Chemo-refractory Colorectal Cancer Patients.

BACKGROUND: Evidence suggests that ctDNA may be a reliable biomarker to monitor metastatic colorectal cancer (CRC) evolution. Nevertheless, evidence on the potential of liquid biopsy in this setting is still low quality, mostly consisting of retrospective studies. METHODS: COPERNIC is an international, multicenter clinical trial. The pilot study aims to confirm the predictive potential of early on-treatment ctDNA dynamics, and inform the design of a larger ctDNA-driven trial. Advanced CRC patients who are candidates for ≥3rd lines of systemic therapy undergo longitudinal blood sample collection during treatment (day 1, 15 and 29 for 2- or 4-weekly treatment regimens; day 1, 22 and 43 for 3-weekly treatment regimens) and at each imaging assessment. ctDNA analyses are carried out with the FoundationOne Liquid CDx and FoundationOneMonitor assays, and ctDNA changes during treatment are correlated with radiologic response (as assessed every 8-12 weeks by RECIST v1.1). The primary objective is to select the optimal timepoint and cut-off value for early ctDNA changes (at day 15/22) to predict progressive disease as best radiological response with a high positive predictive value. The cut-off value for ctDNA will be defined based on nonparametric ROC-curves with bootstrapping. Based on the expected rate of progressive disease and statistical assumptions, 109 patients are needed to be screened to have 87 assessable patients. COPERNIC is sponsored by the Institut Jules Bordet, and supported by Roche and Foundation Medicine. Recruitment is open in 13 centres across Belgium and France. The study is registered with clinicaltrials.gov (NCT05487248).

Preexisting evidence and outcome of phase III trials in gastrointestinal oncology: a systematic review.

BACKGROUND: A minority of phase III trials in gastrointestinal oncology are positive. We assessed the association between their outcome and the level and characteristics of preexisting evidence. METHODS: EMBASE, PubMed, and proceedings from international meetings were searched for phase III gastrointestinal cancer trials (gastroesophageal, hepatocellular, biliary tract, pancreatic, small bowel, colorectal, anal, stromal, and neuroendocrine) between January 2000 and June 2020. Trials investigating anticancer drugs for advanced disease, with superiority design and standard treatments as control were eligible. The highest level of preexisting evidence was retrieved from the main study report. RESULTS: A total of 193 phase III trials were included, and 69 (35.8%) met their primary endpoint. Positivity rates were as follows: gastroesophageal 37%, colorectal 48%, pancreatic 17.1%, hepatocellular 20%, neuroendocrine 75%, and both biliary tract and GIST 60%. No information about preexisting evidence was found for 44 trials (22.8%). For the remaining 149, preexisting evidence consisted of phase II studies in 123 cases (82.6%) and phase I studies in 26 cases (17.4%). The probability of success was 34.1%, 35.8%, and 35.7%, respectively (P = .934). No parameter from prior studies predicted the outcome of phase III trials except ß < .2 (P = .048). A numerically increased success rate was observed for phase III trials preceded by positive phase II studies (41.9% vs 18.5%, P = .2). CONCLUSIONS: There does not appear to be an association between level of prior evidence and success of phase III gastrointestinal cancer trials. These data, along with the high phase III failure rate, highlight the need to improve the drug development process in this setting.

Prognostic Value of Circulating Cytokines in Chemorefractory Colorectal Cancer.

Circulating cytokines could be optimal biomarkers for prognostication and management decisions in colorectal cancer (CRC). Chemorefractory CRC patients with available plasma samples were included in this study. In the discovery cohort (n = 85), 182 circulating cytokines were tested with a semi-quantitative multiplex assay, and prognostic cytokines were analyzed in the validation cohort (n = 111) by ELISA. Overall survival (OS) was the primary outcome measure, with the false discovery rate (FDR) method (significance level of <0.01) being used to correct for multiple comparisons. Four cytokines were associated with OS in the discovery cohort: insulin-like growth factor-binding protein 1 (IGFBP-1) (HR 2.1 [95%CI: 1.58-2.79], FDR < 0.001), insulin-like growth factor-binding protein 2 (IGFBP-2) (HR 1.65 [95%CI: 1.28-2.13], FDR = 0.006), serum amyloid A (SAA) (HR 1.84 [95%CI: 1.39-2.43], FDR < 0.001), and angiotensin II (HR 1.65 [95%CI: 1.29-2.1], FDR = 0.006). Of these, IGFBP-1 (HR 2.70 [95%CI: 1.56-4.76], FDR = 0.007) and IGFBP-2 (HR 3.33 [95%CI: 1.64-6.67], FDR = 0.008) were confirmed to be independently associated with OS in the validation cohort. Patients with high concentrations of IGFBP-1 and/or IGFBP-2 had a median OS of 3.0 months as compared with 6.9 months for those with low concentrations of both cytokines (HR 2.44 [95%CI: 1.52-4.0], FDR = 0.002) Validation of circulating IGFBP-1 and IGFBP-2 as independent prognostic biomarkers for chemorefractory CRC in larger, independent series is warranted.

Toward Targeted Therapies in Oesophageal Cancers: An Overview.

Oesophageal cancer is one of the leading causes of cancer-related death worldwide. Oesophageal cancer occurs as squamous cell carcinoma (ESCC) or adenocarcinoma (EAC). Prognosis for patients with either ESCC or EAC is poor, with less than 20% of patients surviving more than 5 years after diagnosis. A major progress has been made in the development of biomarker-driven targeted therapies against breast and lung cancers, as well as melanoma. However, precision oncology for patients with oesophageal cancer is still virtually non-existent. In this review, we outline the recent advances in oesophageal cancer profiling and clinical trials based on targeted therapies in this disease.

Regorafenib in combination with immune checkpoint inhibitors for mismatch repair proficient (pMMR)/microsatellite stable (MSS) colorectal cancer.

Immune checkpoint inhibitors (ICIs) have marked a new era of cancer treatment, showing remarkable efficacy in a wide range of solid malignancies. In colorectal cancer (CRC), however, the therapeutic potential of ICIs is limited to the small group (≈5%) of patients with mismatch repair deficient (dMMR)/high microsatellite instable (MSI-H) tumours, which are characterised by high mutational/neo-antigen burden, and an inflammatory tumour microenvironment with abundant tumour-infiltrating lymphocytes. Over the last few years, research has focused on immuno-modulatory strategies that could overcome the inherent resistance to ICIs that is observed in the vast group (≈95%) of patients with mismatch repair proficient (pMMR)/microsatellite stable (MSS) tumours. Among these, the combination of ICIs with multi-kinase inhibitors has gained traction in preclinical studies and clinical trials. Thanks to their multiple targets and mechanisms of action, generally involving key cancer pathways such as oncogenesis, angiogenesis, metastasis, and tumour immunity, these agents can exert synergistic effects with ICIs, eventually turning inherently cold cancers into hot tumours, that can be efficiently recognised and targeted by an activated immune system. Regorafenib is routinely used for chemorefractory CRC with limited efficacy. Preliminary evidence, however, suggests that this multi-kinase inhibitor could be an optimal combination partner for ICIs. In this review article, we explain the biological rationale underlying the synergism between regorafenib and ICIs, discuss the available clinical data in CRC, and take a glance into future perspectives by presenting ongoing trials and possible research developments in this setting.

Regorafenib Induces Senescence and Epithelial-Mesenchymal Transition in Colorectal Cancer to Promote Drug Resistance.

Potential intrinsic resistance mechanisms to regorafenib were explored after short exposure (3 days) on five CRC cell lines (HCT-116, SW1116, LS-1034, SW480, Caco-2). The observation of senescence-like features led to the investigation of a drug-initiated phenotype switch. Following long-term exposure (12 months) of HCT-116 and SW480 cell lines to regorafenib, we developed resistant models to explore acquired resistance. SW480 cells demonstrated senescent-like properties, including a cell arrest in the late G2/prophase cell cycle stage and a statistically significant decrease in the expression of G1 Cyclin-Dependent Kinase inhibitors and key cell cycle regulators. A specific senescence-associated secretome was also observed. In contrast, HCT-116 treated cells presented early senescent features and developed acquired resistance triggering EMT and a more aggressive phenotype over time. The gained migration and invasion ability by long-exposed cells was associated with the increased expression level of key cellular and extracellular EMT-related factors. The PI3K/AKT pathway was a significant player in the acquired resistance of HCT-116 cells, possibly related to a PI3KCA mutation in this cell line. Our findings provide new insights into the phenotypic plasticity of CRC cells able, under treatment pressure, to acquire a stable TIS or to use an early senescence state to undergo EMT.

Pre-trial quality assurance of diffusion-weighted MRI for radiomic analysis and the role of harmonisation.

PURPOSE: The aim of this study was to perform a quantitative quality assurance of diffusion-weighted MRI to assess the variability of the mean apparent diffusion coefficient (ADC) and other radiomic features across the scanners involved in the REGINA trial. MATERIALS AND METHODS: The NIST/QIBA diffusion phantom was acquired on six 3 T scanners from five centres with a rectum-specific diffusion protocol. All sequences were repeated in each scan session without moving the phantom from the table. Linear interpolation to two isotropic voxel spacing (0.9 and 4 mm) was performed as well as the ComBat feature harmonisation method between scanners. The absolute accuracy error was evaluated for the mean ADC. Repeatability and reproducibility within-subject coefficients of variation (wCV) were computed for 142 radiomic features. RESULTS: For the mean ADC, accuracy error ranged between 0.1 % and 8.5 %, repeatability was <1 % and reproducibility was <3 % for diffusivity range between 0.4 and 1.1x10-3mm2/s. For the other radiomic features, wCV was below 10 % for 24 % and 15 % features for repeatability with resampling 0.9 mm and 4 mm, respectively, and 13 % and 11 % feature for reproducibility. ComBat method could improve significantly the wCV compared to reproducibility without ComBat (p-value < 0.001) but variation was still high for most of the features. CONCLUSION: Our study provided the first investigation of feature selection for development of robust predictive models in the REGINA trial, demonstrating the added value of such a quality assurance process to select conventional and radiomic features in prospective multicentre trials.

Tackling Refractory Metastatic Colorectal Cancer: Future Perspectives.

Substantial improvements have characterized the systemic treatment of metastatic colorectal cancer (mCRC) over the past 20 years. Besides strong evidence that supports the use of RAS and BRAF status as prognostic and predictive indicators of disease and response, novel technologies have made possible the incorporation of emerging biomarkers for the management of mCRC. On one hand, the discovery of point mutations, amplifications, fusions, and gene expression profiles highlights the genomic and dynamic complexity of CRC. On the other, such discoveries are leading to newer biomarker-driven strategies that add to existing anti-epidermal growth factor receptor (EGFR) and anti-angiogenic approaches. In addition, the availability of a wide molecular profiling has relevant implications for patient prognosis and treatment benefits. Here, we will review the molecular underpinnings and clinical data supporting novel targeted treatments under development for refractory mCRC harboring BRAF mutations, KRAS G12C mutations, HER2 amplification, and less common molecular alterations, such as the re-arrangements of NTRK, ALK, and ROS1. Additionally, we will discuss novel strategies driving the rechallenge of EGFR antibodies and the incorporation of newer anti-angiogenic agents in the therapeutic armamentarium.