Role of oncogenic KRAS in the prognosis, diagnosis and treatment of colorectal cancer

Colorectal cancer (CRC) is a heterogeneous disease at the cellular and molecular levels. Kirsten rat sarcoma (KRAS) is a commonly mutated oncogene in CRC, with mutations in approximately 40% of all CRC cases; its mutations result in constitutive activation of the KRAS protein, which acts as a molecular switch to persistently stimulate downstream signaling pathways, including cell proliferation and survival, thereby leading to tumorigenesis. Patients whose CRC harbors KRAS mutations have a dismal prognosis. Currently, KRAS mutation testing is a routine clinical practice before treating metastatic cases, and the approaches developed to detect KRAS mutations have exhibited favorable sensitivity and accuracy. Due to the presence of KRAS mutations, this group of CRC patients requires more precise therapies. However, KRAS was historically thought to be an undruggable target until the development of KRAS^G12C allele-specific inhibitors. These promising inhibitors may provide novel strategies to treat KRAS-mutant CRC. Here, we provide an overview of the role of KRAS in the prognosis, diagnosis and treatment of CRC.

Treatment of relapse and survival outcomes after liver transplantation in patients with colorectal liver metastases

Liver transplantation (LT) in selected colorectal cancer (CRC) patients with nonresectable liver-only metastases may result in 5-year overall survival of up to about 70-100%. However, the majority will have recurrent disease. All patients included in this report were included in prospective studies. Forty-four out of 56 patients had a relapse, and all 44 patients received treatment for recurrent disease. The organ of the first relapse was lung metastases in 23 of the 44 patients. The first treatment modality of the relapse was the treatment with curative intent in 55.8% of the patients, and chemotherapy was the first treatment administered to 25.6% of the patients. Patients receiving surgery of lung metastases had a 5-year overall survival of 66.5% from the time of metastasectomy. Patients receiving treatment with curative intent for metastases to other organs had a 5-year overall survival of 24.8%. Nine of the 44 patients had no evidence of disease (NED) at the end of the follow-up. Median time of NED in these patients was 54.3 months, and median overall survival from the time of LT was 8.4 years. Because of the high incidence of recurrent disease, these patients should have a systematic long-term follow-up since many of the relapses may be treated with curative intent.

Second-line chemotherapy after early disease progression during first-line chemotherapy containing bevacizumab for patients with metastatic colorectal cancer

Background

The ML18174 study, which showed benefits of bevacizumab (BEV) continuation beyond progression (BBP) for metastatic colorectal cancer (mCRC), excluded patients with first-line progression-free survival (PFS) shorter than 3 months. The present study was conducted to evaluate the efficacy of second-line chemotherapy after early disease progression during first-line chemotherapy containing bevacizumab.

Methods

The subjects of this study were mCRC patients who experienced disease progression < 100 days from commencement of first-line chemotherapy containing BEV initiated between Apr 2007 and Dec 2016. Second-line chemotherapy regimens were classified into two groups with and without BEV/other anti-angiogenic agents (BBP and non-BBP) and efficacy and safety were compared using univariate and multivariate analysis.

Results

Sixty-one patients were identified as subjects of this study. Baseline characteristics were numerically different between BBP (n = 37) and non-BBP (n = 25) groups, such as performance status (0–1/> 2/unknown: 89/8/3 and 56/40/4%), RAS status (wild/mutant/unknown: 32/54/16 and 76/16/8%). Response rate was 8.6% in BBP group and 9.1% in non-BBP group (p = 1.00). Median PFS was 3.9 months in BBP group and 2.8 months in non-BBP group (HR [95%CI]: 0.79 [0.46–1.34], p = 0.373, adjusted HR: 0.87 [0.41–1.82], p = 0.707). Median overall survival was 8.5 months in BBP group and 5.4 months in non-BBP group (HR 0.66 [0.38–1.12], p = 0.125, adjusted HR 0.53 [0.27–1.07], p = 0.078).

Conclusion

In mCRC patients who experienced early progression in first-line chemotherapy, second-line chemotherapy showed poor clinical outcomes regardless use of anti-angiogenic agents.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08890-6.

Reduced-dose of doublet chemotherapy combined with anti-EGFR antibodies in vulnerable older patients with metastatic colorectal cancer: Data from the REVOLT study

OBJECTIVES

To assess the toxicity patterns and effectiveness of doublet chemotherapy when administered at reduced doses of 20% (FOLFOX or FOLFIRI) in combination with anti-EGFR antibodies (cetuximab or panitumumab) in old, vulnerable patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

We performed a retrospective observational study of RAS and BRAF wild-type, vulnerable patients aged ≥70 years with previously untreated mCRC. The primary endpoint was safety, and secondary endpoints were overall response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

One hundred and eighteen patients were collected from 14 selected Italian centres. The median age was 75 (range, 70-85). Geriatric screening by G8 tool gave a score ≤ 14 in all patients. In total, 75 and 43 patients received FOLFOX or FOLFIRI, respectively, in combination with panitumumab (53%) or cetuximab (47%). The overall incidence of grade (G) 3-4 neutropenia was 11.8%, and for skin rash 11%. The most frequent adverse events were G1-2 skin rash (49.1%), G1-2 diarrhea (21.1%) and G1-2 nausea (17.7%). The ORR was 57.3%. Stable disease was observed in 29.1% of patients, with a disease control rate of 86.4%. With a median follow-up of 18 months, the median PFS was 10.0 months (95% confidence interval [CI]: 8.5-11.4), while the median OS was 18.0 months (95% CI: 16.0-19.9). No statistically significant difference was observed between the regimens in terms of ORR, PFS (p = 0.908), and OS (p = 0.832).

CONCLUSION

This study shows that with an appropriate design, including reduced doses, vulnerable older patients best tolerate chemotherapy when combined with anti-EGFR antibodies.

A Possible Distinct Molecular Subtype (Quintuple-Wildtype) of Metastatic Colorectal Cancer in First-Line Anti-EGFR Therapy with Cetuximab Plus FOLFIRI - Palliative Precision Therapy and a Multidisciplinary Treatment Approach: Interim Analysis of the IVOPAK II Trial with Early Results

OBJECTIVE

The study aimed to prospectively evaluate a new molecular biomarker panel (KRAS, NRAS, BRAF, PIK3CA, and ERBB2) for palliative first-line treatment of colorectal cancer (CRC), including a multidisciplinary treatment approach. The rate of secondary metastasis resections was assessed.

PATIENTS AND METHODS

A total of 40 patients with definitively nonresectable metastatic CRC were enrolled from 10 centers before the interim analysis (June 2019) of the IVOPAK II trial (Interdisciplinary Care with Quality Control in Palliative Treatment of Colorectal Cancer). After determination of 5 molecular biomarkers in the tumor (KRAS, exons 2-4; NRAS, exons 2-4; BRAF V600E; PIK3CA; and ERBB2), patients in the IVOPAK II study received FOLFIRI plus cetuximab for all-RAS/quintuple-wildtype disease and FOLFIRI plus bevacizumab in the case of RAS mutations. The current article presents the early description of the clinical outcome of the interim analysis of IVOPAK II comparing the all-RAS/quintuple-wildtype and RAS-mutations populations, including a multidisciplinary-treated case report of a quintuple-wildtype patient.

RESULTS

The quintuple-wildtype population treated with FOLFIRI plus cetuximab in first-line exhibited a significantly higher response rate and enhanced early tumor shrinkage in the interim analysis than the RAS-mutations population, as well as a high rate of secondary metastatic resections.

CONCLUSION

Initial results of this new biomarker panel (quintuple-wildtype) are promising for anti-EGFR therapy with cetuximab plus doublet chemotherapy (FOLFIRI) in first-line treatment of metastatic CRC. These results warrant confirmation with higher case numbers in the IVOPAK II trial.

Resistance to anti-EGFR therapies in metastatic colorectal cancer: underlying mechanisms and reversal strategies

Cetuximab and panitumumab are monoclonal antibodies (mAbs) against epidermal growth factor receptor (EGFR) that are effective agents for metastatic colorectal cancer (mCRC). Cetuximab can prolong survival by 8.2 months in RAS wild-type (WT) mCRC patients. Unfortunately, resistance to targeted therapy impairs clinical use and efficiency. The mechanisms of resistance refer to intrinsic and extrinsic alterations of tumours. Multiple therapeutic strategies have been investigated extensively to overcome resistance to anti-EGFR mAbs. The intrinsic mechanisms include EGFR ligand overexpression, EGFR alteration, RAS/RAF/PI3K gene mutations, ERBB2/MET/IGF-1R activation, metabolic remodelling, microsatellite instability and autophagy. For intrinsic mechanisms, therapies mainly cover the following: new EGFR-targeted inhibitors, a combination of multitargeted inhibitors, and metabolic regulators. In addition, new cytotoxic drugs and small molecule compounds increase the efficiency of cetuximab. Extrinsic alterations mainly disrupt the tumour microenvironment, specifically immune cells, cancer-associated fibroblasts (CAFs) and angiogenesis. The directions include the modification or activation of immune cells and suppression of CAFs and anti-VEGFR agents. In this review, we focus on the mechanisms of resistance to anti-EGFR monoclonal antibodies (anti-EGFR mAbs) and discuss diverse approaches to reverse resistance to this therapy in hopes of identifying more mCRC treatment possibilities.

Distinguishing features of a novel humanized anti-EGFR monoclonal antibody based on cetuximab with superior antitumor efficacy

BACKGROUND

Cetuximab, the first approved EGFR targeting therapeutic antibody, is currently used to treat colorectal cancer and head and neck cancer. While effective, cetuximab is associated with a higher rate of skin rash, infusion reactions, and gastrointestinal toxicity, which was suggested to be linked to the presence of heterogeneous glycan contents on the Fab of the SP2/0-produced cetuximab.

OBJECTIVE AND METHODS

To improve efficacy and minimize toxicity of EGFR inhibition treatment, we re-engineered cetuximab by humanizing its Fab regions and minimizing its glycan contents to generate HLX07.

RESULTS

HLX07 binds to EGFR with similar affinity as cetuximab and shows better bioactivity compared to cetuximab in vitro. In vivo studies demonstrated that HLX07 significantly inhibited the growth of A431, FaDu, NCI-H292, and WiDr tumor cells and synergized them with chemotherapeutics and immune simulator agents such as anti-PD-1. In cynomolgus monkeys, 13-week repeat-dose GLP toxicokinetic studies showed minimal-to-mild toxicities in the dose range of up to 60 mg/kg/wk. In the preliminary phase 1 dose-escalation study, HLX07 had showed lower incidence of skin rashes with grade >2 severities.

CONCLUSION

HLX07 is currently under phase 1/2 clinical development. We believe HLX07 would potentially be an alternative for patients who have been suffering from cetuximab-mediated toxicity.

Signet ring cell carcinoma of the gastrointestinal tract: National trends on treatment effects and prognostic outcomes

BACKGROUND

Signet ring cell carcinoma (SRCC) is a distinct malignancy occurring across the tubular gastrointestinal tract (tGIT). We comprehensively examined the outcomes of patients diagnosed with SRCC across tGIT.

METHODS

SRCC and not-otherwise-specified adenocarcinoma (NOS) patients reported to the National Cancer Database from 2004 to 2015 were included. Baseline characteristics, outcomes and site-specific adjusted hazard ratios (aHR) derived from Cox models of SRCC patients were compared to those of NOS patients. Overall survival (OS) was primary endpoint.

RESULTS

A total of 41,686 SRCC (4.6%) and 871,373 NOS patients (95.4%) were included. SRCC patients were younger (63.1 ± 14.7 vs. 67.0 ± 13.4 y, p < 0.001) and more likely to present with Stage IV disease than NOS patients (42.5% vs. 24.5%, p < 0.001). Stomach (n = 24,433) and colon (n = 9,914) contributed highest frequency of SRCC. SRCC histology was associated with shorter OS (aHR = 1.377, p < 0.001) in multivariate model. There was an interaction between SRCC and chemotherapy effects on risk of death (interaction aHR = 1.072, p_interaction< 0.001) and between SRCC histology and disease site, suggesting that the effect of SRCC on OS is site-dependent, with a higher increased risk of death in patients with rectal SRCC (aHR = 2.378, p_interaction< 0.001).

CONCLUSION

Significant negative prognostic effect associated with SRCC is site-dependent across the GIT. Surgical and or systemic therapy was associated with improved OS among SRCC patients, but remained lower than NOS patients. Further understanding of gastrointestinal SRCC molecular profile is needed to better inform future treatment strategies.

Repeat Local Treatment of Recurrent Colorectal Liver Metastases, the Role of Neoadjuvant Chemotherapy: An Amsterdam Colorectal Liver Met Registry (AmCORE) Based Study

This cohort study aimed to evaluate efficacy, safety, and survival outcomes of neoadjuvant chemotherapy (NAC) followed by repeat local treatment compared to upfront repeat local treatment of recurrent colorectal liver metastases (CRLM). A total of 152 patients with 267 tumors from the prospective Amsterdam Colorectal Liver Met Registry (AmCORE) met the inclusion criteria. Two cohorts of patients with recurrent CRLM were compared: patients who received chemotherapy prior to repeat local treatment (32 patients) versus upfront repeat local treatment (120 patients). Data from May 2002 to December 2020 were collected. Results on the primary endpoint overall survival (OS) and secondary endpoints local tumor progression-free survival (LTPFS) and distant progression-free survival (DPFS) were reviewed using the Kaplan-Meier method. Subsequently, uni- and multivariable Cox proportional hazard regression models, accounting for potential confounders, were estimated. Additionally, subgroup analyses, according to patient, initial and repeat local treatment characteristics, were conducted. Procedure-related complications and length of hospital stay were compared using chi-square test and Fisher's exact test. The 1-, 3-, and 5-year OS from date of diagnosis of recurrent disease was 98.6%, 72.5%, and 47.7% for both cohorts combined. The crude survival analysis did not reveal a significant difference in OS between the two cohorts (p = 0.834), with 1-, 3-, and 5-year OS of 100.0%, 73.2%, and 57.5% for the NAC group and 98.2%, 72.3%, and 45.3% for the upfront repeat local treatment group, respectively. After adjusting for two confounders, comorbidities (p = 0.010) and primary tumor location (p = 0.023), the corrected HR in multivariable analysis was 0.839 (95% CI, 0.416-1.691; p = 0.624). No differences between the two cohorts were found with regards to LTPFS (HR = 0.662; 95% CI, 0.249-1.756; p = 0.407) and DPFS (HR = 0.798; 95% CI, 0.483-1.318; p = 0.378). No heterogeneous treatment effects were detected in subgroup analyses according to patient, disease, and treatment characteristics. No significant difference was found in periprocedural complications (p = 0.843) and median length of hospital stay (p = 0.600) between the two cohorts. Chemotherapy-related toxicity was reported in 46.7% of patients. Adding NAC prior to repeat local treatment did not improve OS, LTPFS, or DPFS, nor did it affect periprocedural morbidity or length of hospital stay. The results of this comparative assessment do not substantiate the routine use of NAC prior to repeat local treatment of CRLM. Because the exact role of NAC (in different subgroups) remains inconclusive, we are currently designing a phase III randomized controlled trial (RCT), COLLISION RELAPSE trial, directly comparing upfront repeat local treatment (control) to neoadjuvant systemic therapy followed by repeat local treatment (intervention).

A phospho-proteomic study of cetuximab resistance in KRAS/NRAS/BRAFV600 wild-type colorectal cancer

PURPOSE

We hypothesised that plasticity in signal transduction may be a mechanism of drug resistance and tested this hypothesis in the setting of cetuximab resistance in patients with KRAS/NRAS/BRAFV600 wild-type colorectal cancer (CRC).

METHODS

A multiplex antibody-based platform was used to study simultaneous changes in signal transduction of 55 phospho-proteins in 12 KRAS/NRAS/BRAFV600 wild-type CRC cell lines (6 cetuximab sensitive versus 6 cetuximab resistant) following 1 and 4 h in vitro cetuximab exposure. We validated our results in CRC patient samples (n = 4) using ex vivo exposure to cetuximab in KRAS/NRAS/BRAFV600 cells that were immunomagnetically separated from the serous effusions of patients with known cetuximab resistance.

RESULTS

Differences in levels of phospho-proteins in cetuximab sensitive and resistant cell lines included reductions in phospho-RPS6 and phospho-PRAS40 in cetuximab sensitive, but not cetuximab resistant cell lines at 1 and 4 h, respectively. In addition, phospho-AKT levels were found to be elevated in 3/4 patient samples following ex vivo incubation with cetuximab for 1 h. We further explored these findings by studying the effects of combinations of cetuximab and two PI3K pathway inhibitors in 3 cetuximab resistant cell lines. The addition of PI3K pathway inhibitors to cetuximab led to a significantly higher reduction in colony formation capacity compared to cetuximab alone.

CONCLUSION

Our findings suggest activation of the PI3K pathway as a mechanism of cetuximab resistance in KRAS/NRAS/BRAFV600 wild-type CRC.

A human antibody against human endothelin receptor type A that exhibits antitumor potency

Endothelin receptor A (ET_A), a class A G-protein-coupled receptor (GPCR), is involved in the progression and metastasis of colorectal, breast, lung, ovarian, and prostate cancer. We overexpressed and purified human endothelin receptor type A in Escherichia coli and reconstituted it with lipid and membrane scaffold proteins to prepare an ET_A nanodisc as a functional antigen with a structure similar to that of native GPCR. By screening a human naive immune single-chain variable fragment phage library constructed in-house, we successfully isolated a human anti-ET_A antibody (AG8) exhibiting high specificity for ET_A in the β-arrestin Tango assay and effective inhibitory activity against the ET-1-induced signaling cascade via ET_A using either a CHO-K1 cell line stably expressing human ET_A or HT-29 colorectal cancer cells, in which AG8 exhibited IC₅₀ values of 56 and 51 nM, respectively. In addition, AG8 treatment repressed the transcription of inhibin βA and reduced the ET_A-induced phosphorylation of protein kinase B and extracellular regulated kinase. Furthermore, tumor growth was effectively inhibited by AG8 in a colorectal cancer mouse xenograft model. The human anti-ET_A antibody isolated in this study could be used as a potential therapeutic for cancers, including colorectal cancer.

A therapeutic antibody that targets a receptor involved in cancer progression shows significant anti-cancer effects in trials in mice. Endothelin receptor A (ET_A) promotes the progression and metastasis of several cancers, and patients with high ET_A expression often have poor survival rates. Several small molecule drugs that target ET_A are currently undergoing trials. Now, Sang Taek Jung at the Korea University in Seoul, together with scientists across South Korea, have identified and isolated a human antibody that specifically binds to ET_A. The team developed an antigen that mimics ET_A, and identified and isolated the antibody it bound to. The antibody exhibited potent anti-tumor effects in cell cultures and trials in mice. Such therapeutic antibodies show higher affinity for their targets than other drugs, resulting in fewer side effects and higher efficacy.

BRAF V600E Mutation in First-Line Metastatic Colorectal Cancer: An Analysis of Individual Patient Data From the ARCAD Database

BACKGROUND

First-line therapeutic strategies for patients with BRAFV600E-mutated (BRAFmt) metastatic colorectal cancer (mCRC) mainly rely on subgroup analyses from randomized controlled trials (RCTs). We aimed to assess the prognostic and predictive impact of BRAFmt on the efficacy of targeted therapies with first-line chemotherapy.

METHODS

Individual patient data from first-line RCTs with BRAF and KRAS status data in the ARCAD database were pooled. Progression-free survival and overall survival (OS) were assessed using Kaplan-Meier and Cox models. Outcomes were compared between treatment groups that were concurrently randomly assigned whenever possible.

RESULTS

A total of 6391 patients from 10 RCTs were included: 573 BRAFmt (9.0%), 2059 KRASmt (32.2%), and 3759 double wild type (58.8%). BRAFmt mCRC patients experienced statistically significantly poorer OS than those with KRASmt (adjusted hazard ratio [HRadj] = 1.46, 95% confidence interval [CI] = 1.30 to 1.64) and patients with double wild-type tumors (HRadj = 2.14, 95% CI = 1.94 to 2.36). Anti-EGFR agents did not improve progression-free survival or OS of BRAFmt mCRC patients, based on 4 RCTs testing chemotherapy with or without anti-epidermal growth factor receptor (anti-EGFR) (HRadj = 0.96, 95% CI = 0.71 to 1.30; and HRadj = 0.85, 95% CI = 0.66 to 1.14, respectively).

CONCLUSIONS

Our data suggest that the addition of anti-EGFR agents to chemotherapy is ineffective as first-line treatment for BRAFmt mCRC patients.

Molecular subtype-specific efficacy of anti-EGFR therapy in colorectal cancer is dependent on the chemotherapy backbone

BACKGROUND

Patient selection for addition of anti-EGFR therapy to chemotherapy for patients with RAS and BRAF wildtype metastatic colorectal cancer can still be optimised. Here we investigate the effect of anti-EGFR therapy on survival in different consensus molecular subtypes (CMSs) and stratified by primary tumour location.

METHODS

Retrospective analyses, using the immunohistochemistry-based CMS classifier, were performed in the COIN (first-line oxaliplatin backbone with or without cetuximab) and PICCOLO trial (second-line irinotecan with or without panitumumab). Tumour tissue was available for 323 patients (20%) and 349 (41%), respectively.

RESULTS

When using an irinotecan backbone, anti-EGFR therapy is effective in both CMS2/3 and CMS4 in left-sided primary tumours (progression-free survival (PFS): HR 0.44, 95% CI 0.26-0.75, P = 0.003 and HR 0.12, 95% CI 0.04-0.36, P < 0.001, respectively) and in CMS4 right-sided tumours (PFS HR 0.17, 95% CI 0.04-0.71, P = 0.02). Efficacy using an oxaliplatin backbone was restricted to left-sided CMS2/3 tumours (HR 0.57, 95% CI 0.36-0.96, P = 0.034).

CONCLUSIONS

The subtype-specific efficacy of anti-EGFR therapy is dependent on the chemotherapy backbone. This may provide the possibility of subtype-specific treatment strategies for a more optimal use of anti-EGFR therapy.

Precision Medicine for Colorectal Cancer with Liquid Biopsy and Immunotherapy

Simple Summary

There are some challenges to improve the clinical outcome of colorectal cancers (CRCs) by implementing new technologies, such as early detection of recurrence/relapse and selection of appropriate drugs based on the genomic profiles of tumors. For example, the genomic characteristics of tumors can be analyzed by blood-based tests, namely ‘liquid biopsies’, which are minimally-invasive and can be performed repeatedly during the treatment course. Hence, liquid biopsies are considered to hold great promise to fill these gaps in clinical routines. In this review, we addressed clinical usefulness of liquid biopsies in the clinical management of CRC patients, including cancer screening, detection of minimal residual disease, selection of appropriate molecular-targeted drugs, monitoring of the treatment responsiveness, and very early detection of recurrence/relapse of the disease. Furthermore, we discussed the possibility of adoptive T cell therapies and a future personalized immunotherapy based on tumor genome information.

Abstract

In the field of colorectal cancer (CRC) treatment, diagnostic modalities and chemotherapy regimens have progressed remarkably in the last two decades. However, it is still difficult to identify minimal residual disease (MRD) necessary for early detection of recurrence/relapse of tumors and to select and provide appropriate drugs timely before a tumor becomes multi-drug-resistant and more aggressive. We consider the leveraging of in-depth genomic profiles of tumors as a significant breakthrough to further improve the overall prognosis of CRC patients. With the recent technological advances in methodologies and bioinformatics, the genomic profiles can be analyzed profoundly without delay by blood-based tests—‘liquid biopsies’. From a clinical point of view, a minimally-invasive liquid biopsy is thought to be a promising method and can be implemented in routine clinical settings in order to meet unmet clinical needs. In this review, we highlighted clinical usefulness of liquid biopsies in the clinical management of CRC patients, including cancer screening, detection of MRD, selection of appropriate molecular-targeted drugs, monitoring of the treatment responsiveness, and very early detection of recurrence/relapse of the disease. In addition, we addressed a possibility of adoptive T cell therapies and a future personalized immunotherapy based on tumor genome information.

Initial experience of TAS-102 chemotherapy in Australian patients with Chemo-refractory metastatic colorectal cancer

For patients with refractory metastatic colorectal cancer (mCRC) treatment with Trifluridine/Tipiracil, also known as TAS-102, improves overall survival. This study aims to investigate the efficacy and safety of TAS-102 in a real-world population from Victoria, Australia. A retrospective analysis of prospectively collected data from the Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry was undertaken. The characteristics and outcomes of patients receiving TAS-102 were assessed and compared to those enrolled in the registration study (RECOURSE). Across 13 sites, 107 patients were treated with TAS-102. The median age was 60 years (range: 31-83), compared to 63 for RECOURSE. Comparing registry TAS-102-treated and RECOURSE patients, 75% vs 100% were ECOG performance status 0-1, 74% vs 79% had initiated treatment more than 18 months from diagnosis of metastatic disease and 36% vs 49% were RAS wild-type. Median time on treatment was 10.4 weeks (range: 1.7-32). Median progression-free survival (PFS) was 3.3 months compared to 2 months in RECOURSE, while median overall survival was the same at 7.1 months. Two patients (2.3%) had febrile neutropenia and there were no treatment-related deaths, where TAS-102 dose at treatment initiation was at clinician discretion.TRACC registry patients treated with TAS-102 were younger than those from the RECOURSE trial, with similar overall survival observed. Less strict application of RECIST criteria and less frequent imaging may have contributed to an apparently longer PFS.

The best strategy for metastatic colorectal cancer (mCRC) patients in second-line treatment: A network meta-analysis

BACKGROUND

Varieties of systemic treatments in second-line treatment for metastatic colorectal cancer (mCRC) patients have showed an improvement on survival. In this study, we performed a systematic review with a pairwise and bayesian network meta-analysis to rank the best strategy for mCRC patients in second-line treatment.

METHODS

A systematic literature search through 2007 was performed to evaluate the association between several treatment combinations and overall survival (OS), progression-free survival (PFS) and disease control rate (DCR) in mCRC patients. Data were carried out and pooled into a statistical indirect comparison with Bayesian network meta-analysis (NMA).

RESULTS

10 trials totally comprised 4183 patients were included in our study. In NMA, For PFS, Doublet+Bev showed benefits in comparing with Doublet, Doulblet+placebo and Doublet+Ramucirumab. Also, Doublet+Aflibercept demonstrated its superiority in comparing with Doulblet+placebo. For OS, Doublet+Bev represented its superiority when comparing with Double and Doublet+placebo. Doublet+Aflibercept and Doublet+Ramucirumab also done well when opposed to Doublet+placebo. For DCR, Doublet+bev showed unique superiority when compared with Doublet, And Doublet+targeted agent did not represent benefits to each other in DCR. Doublet+bev ranked highest in terms of PFS, OS and DCR followed by Doublet+panitumumab, Doublet+placebo was the lowest in terms of PFS and OS.

CONCLUSIONS

Our study shows that Doublet+Bev has the major probability to provide an improvement of survival in patients with mCRC.

Neoadjuvant chemotherapy for colorectal liver metastases: A contemporary review of the literature

Colorectal carcinoma (CRC) is one of the leading causes of cancer-related deaths worldwide, and up to 50% of patients with CRC develop colorectal liver metastases (CRLM). For these patients, surgical resection remains the only opportunity for cure and long-term survival. Over the past few decades, outcomes of patients with metastatic CRC have improved significantly due to advances in systemic therapy, as well as improvements in operative technique and perioperative care. Chemotherapy in the modern era of oxaliplatin- and irinotecan-containing regimens has been augmented by the introduction of targeted biologics and immunotherapeutic agents. The increasing efficacy of contemporary systemic therapies has led to an expansion in the proportion of patients eligible for curative-intent surgery. Consequently, the use of neoadjuvant strategies is becoming progressively more established. For patients with CRLM, the primary advantage of neoadjuvant chemotherapy (NCT) is the potential to down-stage metastatic disease in order to facilitate hepatic resection. On the other hand, the routine use of NCT for patients with resectable metastases remains controversial, especially given the potential risk of inducing chemotherapy-associated liver injury prior to hepatectomy. Current guidelines recommend upfront surgery in patients with initially resectable disease and low operative risk, reserving NCT for patients with borderline resectable or unresectable disease and high operative risk. Patients undergoing NCT require close monitoring for tumor response and conversion of CRLM to resectability. In light of the growing number of treatment options available to patients with metastatic CRC, it is generally agreed that these patients are best served at tertiary centers with an expert multidisciplinary team.

Delayed MRI Enhancement of Colorectal Cancer Liver Metastases Is Associated With Metastatic Mutational Profile

BACKGROUND/AIM

Individual tumor genomics plays a key role in determining patient prognosis, response to chemotherapy and in guiding therapy. In prior studies, it was shown that the degree of late enhancement of colorectal liver metastases (CRCLM) target tumor enhancement (TTE) as seen on magnetic resonance imaging (MRI) was associated with overall survival. In order to better understand the relationship between MRI enhancement and survival, the aim of this study was to characterize genomic profiles of tumors clustered by MRI TTE, and investigate the association between TTE and genetic mutations.

MATERIALS AND METHODS

Matched tumor and normal tissue samples from patients with weak TTE and strong TTE were analyzed by Next-generation sequencing (NGS) technology using a custom colorectal cancer panel.

RESULTS

We discovered a total of 42 non-synonymous somatic mutations from 10 patients with weak TTE and 26 with 10 patients with strong TTE. Adenomatosis Polyposis Coli (APC) was the most commonly altered gene, 18 of those APC mutations were found in the weak TTE and 9 in the strong TTE group.

CONCLUSION

An association exists between TTE and mutational status of CRCLM, which may offer some explanation as to why TTE is associated with overall survival in patients with CRCLM.

The Real-Life Data of BRAF Mutation on the Treatment of Colorectal Cancer: a TOG Study

PURPOSE

Colorectal cancer is the third leading diagnosis accounting for nearly 10% of all new cancers worldwide. The distinct features among BRAF mutant colorectal cancers make these tumor groups hard to treat for oncologists. The median overall survival (OS) of these types of cancers is reported to be 9 to 14 months.

METHODS

The study was declared on the Turkish Oncology Study Group Conference and approved. The patients' data was received from the centers who confirmed to participate. The BRAF-mutated patients were included in the study. The demographic features (age, gender, etc.), type of mutation, tumor localizations, histology, microsatellite instability (MSI) status, metastasis patterns chemotherapeutic agents and progression, and death times were recorded.

RESULTS

Thirty-nine patients were enrolled in the study. Sixteen patients had concurrent KRAS mutations, while 7 had NRAS mutations. Most of the patients received doublet chemotherapies in combination with anti-VEGF agents in the first and second line of the treatment. There was a significant difference in OS according to the stage which showed a decreased survival in stage IV patients at the time of diagnosis. Concurrent KRAS mutation resulted in increased OS. The median OS was 47 and 24 months favoring the KRAS mutant group. The patients whose primary tumor operated had better survival when compared with other patients. The median OS of the operated group was 47 months, while the non-operated group was 24 months. Liver metastasis was related to worse prognosis at the time of diagnosis in univariate analysis.

CONCLUSION

In our study we found a high concurrent RAS mutation ratio in a BRAF mutant patient group which was different from prior studies. The concurrent mutations resulted in a favorable outcome in terms of OS which is also different from the current knowledge. More prospective studies are needed especially BRAF-mutated patient population and especially with concurrent RAS mutations.

New Indications for Liver Transplantation

Liver transplantation (LT) is an important therapeutic option for the treatment of several liver diseases. Modern LT is characterized by remarkable improvements in post-transplant patient survival, graft survival, and quality of life. Thanks to these great improvements, indications for LT are expanding. Nowadays, clinical conditions historically considered exclusion criteria for LT, have been considered new indications for LT, showing survival advantages for patients. In this review, we provide an updated overview of the principal newer indications for LT, with particular attention to alcoholic hepatitis, acute-on-chronic liver failure (ACLF), cholangiocarcinoma and colorectal cancer metastases.

Liver transplantation in malignant disease

Liver transplantation for malignant disease has gained increasing attention as part of transplant oncology. Following the implementation of the Milan criteria, hepatocellular carcinoma (HCC) was the first generally accepted indication for transplantation in patients with cancer. Subsequently, more liberal criteria for HCC have been developed, and research on this topic is still ongoing. The evident success of liver transplantation for HCC has led to the attempt to extend its indication to other malignancies. Regarding perihilar cholangiocarcinoma, more and more evidence supports the use of liver transplantation, especially after neoadjuvant therapy. In addition, some data also show a benefit for selected patients with very early stage intrahepatic cholangiocarcinoma. Hepatic epithelioid hemangioendothelioma is a very rare but nonetheless established indication for liver transplantation in primary liver cancer. In contrast, patients with hepatic angiosarcoma are currently not considered to be optimal candidates. In secondary liver tumors, neuroendocrine cancer liver metastases are an accepted but comparability rare indication for liver transplantation. Recently, some evidence has been published supporting the use of liver transplantation even for colorectal liver metastases. This review summarizes the current evidence for liver transplantation for primary and secondary liver cancer.

Phase II Trial of Trametinib and Panitumumab in RAS/RAF Wild Type Metastatic Colorectal Cancer

INTRODUCTION

MEK inhibition may overcome resistance to EGFR inhibition in patients with RAS wildtype (wt) metastatic colorectal cancer (mCRC). We evaluated antitumor activity of trametinib (MEK1/2 inhibitor) with panitumumab (EGFR monoclonal antibody) in a phase II trial.

METHODS

Patients with KRAS, NRAS, and BRAF wt mCRC with prior 5-FU, irinotecan, oxaliplatin, +/- bevacizumab and no prior anti-EGFR therapy were treated with trametinib 1.5 mg oral daily and panitumumab 4.8 mg/kg IV every 2 weeks. Primary endpoint was clinical benefit rate (CB; CR, PR, or SD ≥24 weeks) by RECIST v1.1. A 2-stage minimax design was used. Serial plasma circulating free DNA (cfDNA) was collected and profiled using Oncomine Lung cfDNA assay.

RESULTS

Fourteen patients were enrolled from November 2015 to April 2019. CB rate was 38% (5/13) and median progression free survival (PFS) was 4.4 months (95% CI, 2.9-7.1). Confirmed overall response rate was 38% (5/13). Treatment-related AE (trAE) included acneiform rash (85%), diarrhea (62%), maculopapular rash (54%), mucositis (46%), and others. Dose modifications and interruptions of trametinib occurred in 69% and panitumumab in 54% of patients. The trial did not progress to stage II accrual due to tolerability and short duration of response. RAS or BRAF mutations cfDNA were detected in 3/13 patients (23%) before radiographic disease progression.

CONCLUSION

The addition of trametinib to panitumumab led to a high rate of tumor shrinkage in RAS/RAF wt metastatic colorectal cancer, with poor tolerability due to a high incidence of skin toxicity. Median PFS was similar to panitumumab alone in historical control data.

FGFR2-TSC22D1, a novel FGFR2 fusion gene identified in a patient with colorectal cancer: A case report

BACKGROUND

The FGFR signaling pathway is activated in multiple tumor types through gene amplifications, single base substitutions, or gene fusions. Novel FGFR gene fusions may represent candidate targets for the development of tyrosine kinase inhibitors.

CASE SUMMARY

Herein, we report a patient with colorectal cancer (CRC) harboring a novel FGFR2 fusion gene. A 59-year-old man felt discomfort in his right upper abdomen with loss of appetite for 6 mo. An abdominal computed tomography scan revealed the existence of a space-occupying lesion in the ascending colon. The pathological diagnosis was a poorly differentiated adenocarcinoma. Subsequent biopsy specimen was subjected to next-generation sequencing analysis, and a novel FGFR2-TSC22D1 fusion with complete kinase structure of FGFR2 protein was identified.

CONCLUSION

We report the first case of CRC harboring FGFR2-TSC22D1, which enriches the FGFR2 fusion spectrum. FGFR2 inhibitors might be effective in the later treatment for this patient.

Primary Tumor Sidedness, RAS and BRAF Mutations and MSI Status as Prognostic Factors in Patients with Colorectal Liver Metastases Treated with Surgery and Thermal Ablation: Results from the Amsterdam Colorectal Liver Met Registry (AmCORE)

The aim of this study was to assess primary tumor sidedness of colorectal cancer (CRC), rat sarcoma viral oncogene homolog (RAS) and v-raf murine sarcoma viral oncogene homolog B (BRAF) mutations and microsatellite instability (MSI) status as prognostic factors predicting complications, survival outcomes, and local tumor progression (LTP) following surgery and thermal ablation in patients with colorectal liver metastases (CRLM). This Amsterdam Colorectal Liver Met Registry (AmCORE) based study included 520 patients, 774 procedures, and 2101 tumors undergoing local treatment (resection and/or thermal ablation) from 2000 to 2021. Outcomes following local treatment were analyzed for primary tumor sidedness of CRC, RAS, and BRAF mutations and MSI status. The Kaplan–Meier method was used to estimate local tumor progression-free survival (LTPFS), local control (LC), distant progression-free survival (DPFS), and overall survival (OS). Uni- and multivariable analyses were performed based on Cox proportional hazards model. The chi-square test was used to analyze complications. Complications (p = 0.485), OS (p = 0.252), LTPFS (p = 0.939), and LC (p = 0.423) was not associated with tumor-sidedness. Compared to right-sided colon cancer (CC) (reference HR 1.000), DPFS was superior for left-sided CC and rectal cancer (p = 0.018) with an HR for left-sided CC of 0.742 (95% CI, 0.596–0.923) and for RC of 0.760 (95% CI, 0.597–0.966). Regarding RAS mutations, no significant difference was found in OS (p = 0.116). DPFS (p = 0.001), LTPFS (p = 0.039), and LC (p = 0.025) were significantly lower in the RAS mutation group. Though no difference in LTPFS was found between RAS wildtype and RAS mutated CRLM following resection (p = 0.532), LTPFS was worse for RAS mutated tumors compared to RAS wildtype following thermal ablation (p = 0.037). OS was significantly lower in the BRAF mutation group (p < 0.001) and in the MSI group (p < 0.001) following local treatment, while both did not affect DPFS, LTPFS, and LC. This AmCORE based study suggests the necessity of wider margins to reduce LTP rates in patients with RAS mutated CRLM, especially for thermal ablation. Upfront knowledge regarding molecular biomarkers may contribute to improved oncological outcomes.

The potential use of extended criteria donors and eligible recipients in liver transplantation for unresectable colorectal liver metastases in Central Sweden

BACKGROUND

Unresectable colorectal liver metastases (CRLM) is a condition with poor prognosis. A recent treatment alternative improving survival in patients with unresectable CRLM, has emerged with the introduction of liver transplantation (LT), yet not uncontroversial with the current organ shortage. This study aimed to retrospectively investigate the potential of declined donors with acceptable risk as liver graft donors and patients with unresectable CRLM as potential recipients.

METHODS

All declined donors in central Sweden and all patients with CRLM discussed at multidisciplinary team conference at Karolinska University Hospital, January 2013-October 2018, were identified. Donors were classified according to the European Committee Guide to the quality and safety of organs for transplantation and potential recipients were evaluated by selection criteria, based on studies on the Norwegian Secondary Cancer study database.

RESULTS

Out of 1,462 evaluated potential donors, 62 (2.7 pmp) donors were identified, corresponding to 6-18% of the utilized donor pool. Out of 1,008 included patients with CRLM, 25 (2.1 pmp) potential recipients were recognized. Eligibility for LT and left-sided colon cancer were favorable prognostic factors.

CONCLUSIONS

Today's donor pool could increase with the use of extended criteria donors, which is sufficient and display an acceptable risk-benefit ratio for patients with unresectable CRLM. With current selection criteria a small subset of patients with unresectable CRLM are eligible recipients. This subset of patients has a better survival compared to patients ineligible for LT.

Treatment and Outcomes of Colorectal Cancer in Armenia: A Real-World Experience From a Developing Country

PURPOSE

In Armenia, colorectal cancer (CRC) is one of the most frequently diagnosed cancers. It is in the third place by incidence. The aim of this study was to evaluate treatment and outcomes of CRC in Armenia during the last 9 years.

MATERIALS AND METHODS

For this retrospective hospital-based study, we have collected data from two main oncology centers in Armenia: National Oncology Center and “Muratsan” Hospital of Yerevan State Medical University. The information about patients with CRC who were treated at these two centers between January 1, 2010 and July 1, 2018 was collected from the medical records. Log-rank test and Kaplan-Meier curves were used for survival analysis. Prognostic factors were identified by Cox regression.

RESULTS

A total of 602 patients with CRC were involved in the final analysis. Median follow-up time was 37 months (range, 3-207 months). A total of 8.6% of patients had stage I, 32.9% stage II, 38.0% stage III, and 17.6% stage IV cancer; for 2.7% patients, the stage was unknown. The main independent prognostic factors for overall survival (OS) were tumor stage, grade, and histology. Adjuvant chemotherapy has been shown to improve survival in stage II colon cancer and stage III rectal but not in stage II rectal cancer. Radiotherapy did not yield survival improvement in stage II or III rectal cancer. Three- and 5-year OS rates were 62.9% and 51.8% for all stages combined and 79.7% and 68.5% for stages I-II, 62.5% and 48.4% for stage III, and 24.4% and 17% for stage IV respectively.

CONCLUSION

As seen from our results, our survival rates are lower than those of the developed world. Additional research is needed to identify the underlying reasons and to improve patients’ treatment and outcomes in Armenia.

Colorectal Cancer, Liver Metastases and Biotherapies

(1) Background: colorectal cancer (CRC) is one of the deadliest causes of death by cancer worldwide. Its first main metastatic diffusion spreads to the liver. Different mechanisms such as the epithelial-mesenchymal transition and angiogenesis are the characteristics of this invasion. At this stage, different options are possible and still in debate, especially regarding the use of targeted therapeutics and biotherapies. (2) Methods: A review of the literature has been done focusing on the clinical management of liver metastasis of colorectal cancer and the contribution of biotherapies in this field. (3) Results: In a clinical setting, surgeons and oncologists consider liver metastasis in CRC into two groups to launch adapted therapeutics: resectable and non-resectable. Around these two entities, the combination of targeted therapies and biotherapies are of high interest and are currently tested to know in which molecular and clinical conditions they have to be applied to impact positively both on survival and quality of life of patients.

Emerging strategies to target RAS signaling in human cancer therapy

RAS mutations (HRAS, NRAS, and KRAS) are among the most common oncogenes, and around 19% of patients with cancer harbor RAS mutations. Cells harboring RAS mutations tend to undergo malignant transformation and exhibit malignant phenotypes. The mutational status of RAS correlates with the clinicopathological features of patients, such as mucinous type and poor differentiation, as well as response to anti-EGFR therapies in certain types of human cancers. Although RAS protein had been considered as a potential target for tumors with RAS mutations, it was once referred to as a undruggable target due to the consecutive failure in the discovery of RAS protein inhibitors. However, recent studies on the structure, signaling, and function of RAS have shed light on the development of RAS-targeting drugs, especially with the approval of Lumakras (sotorasib, AMG510) in treatment of KRASG12C-mutant NSCLC patients. Therefore, here we fully review RAS mutations in human cancer and especially focus on emerging strategies that have been recently developed for RAS-targeting therapy.

The Impact of Long-Term Antibiotic Therapy of Cutaneous Adverse Reactions to EGFR Inhibitors in Colorectal Cancer Patients

Colorectal cancer (CRC) is an important public health issue, in terms of incidence and mortality, with approximately 1.8 million new cases reported worldwide in 2018. Advancements in understanding pathophysiological key steps in CRC tumorigenesis have led to the development of new targeted therapies such as those based on epidermal growth factor receptor inhibitors (EGFR inhibitors). The cutaneous adverse reactions induced by EGFR inhibitors, particularly papulopustular rash, often require long-term antibiotic treatment with tetracycline agents (mostly minocycline and doxycycline). However, this raises several issues of concern: possible occurrence of gut dysbiosis in already vulnerable CRC patients, selection of highly antibiotic resistant and/or virulent clones, development of adverse reactions related to tetracyclines, interference of antibiotics with the response to oncologic therapy, with a negative impact on disease prognosis etc. In the context of scarce information regarding these issues and controversial opinions regarding the role of tetracyclines in patients under EGFR inhibitors, our aim was to perform a thorough literature review and discuss the main challenges raised by long-term use of tetracyclines in advanced CRC patients receiving this targeted therapy.

Evidence-Based Second-Line Treatment in RAS Wild-Type/Mutated Metastatic Colorectal Cancer in the Precision Medicine Era

Target-oriented agents improve metastatic colorectal cancer (mCRC) survival in combination with chemotherapy. However, the majority of patients experience disease progression after first-line treatment and are eligible for second-line approaches. In such a context, antiangiogenic and anti-Epidermal Growth Factor Receptor (EGFR) agents as well as immune checkpoint inhibitors have been approved as second-line options, and RAS and BRAF mutations and microsatellite status represent the molecular drivers that guide therapeutic choices. Patients harboring K- and N-RAS mutations are not eligible for anti-EGFR treatments, and bevacizumab is the only antiangiogenic agent that improves survival in combination with chemotherapy in first-line, regardless of RAS mutational status. Thus, the choice of an appropriate therapy after the progression to a bevacizumab or an EGFR-based first-line treatment should be evaluated according to the patient and disease characteristics and treatment aims. The continuation of bevacizumab beyond progression or its substitution with another anti-angiogenic agents has been shown to increase survival, whereas anti-EGFR monoclonals represent an option in RAS wild-type patients. In addition, specific molecular subgroups, such as BRAF-mutated and Microsatellite Instability-High (MSI-H) mCRCs represent aggressive malignancies that are poorly responsive to standard therapies and deserve targeted approaches. This review provides a critical overview about the state of the art in mCRC second-line treatment and discusses sequential strategies according to key molecular biomarkers.

Landscape of Current Targeted Therapies for Advanced Colorectal Cancer

Colorectal cancer (CRC) is one of the most frequent and lethal cancer types worldwide. While surgery with chemotherapy and radiotherapy remains the only curative approach for localized CRC, for metastatic disease the therapeutic landscape has significantly evolved over the last years. Development and approval of novel targeted therapies, such as monoclonal antibodies against EGFR and VEGF, have significantly increased the median survival of patients with metastatic disease, with some trials reporting a benefit over 40 months. Increasing accessibility of high throughput sequencing has unraveled several new therapeutic targets. Actionable alterations, such as HER2 overexpression, BRAF mutations, and NTRK fusions, are currently available in metastatic disease, providing significant therapeutic opportunities for these patients, while new emerging agents, as immune checkpoint inhibitors, promise better treatment options in the near future. In this chapter, an overview of established and future CRC targeted therapies in the clinical setting is provided, as well as their mechanism of action, limitations, and future applicability.

The Evolving Field of Neoadjuvant Therapy in Locally-advanced Rectal Cancer: Evidence and Prospects

The standard treatment of locally advanced rectal cancer comprises neoadjuvant chemoradiation followed by total mesorectal excision. This strategy provides low local recurrence rate, however distant recurrence is still an issue and may impact on survival rates. Novel approaches in the neoadjuvant setting have been tested to improve early and late outcomes, as well as to reduce treatment-related toxicity and morbidity. In this review, we discuss the current literature of neoadjuvant treatment in locally advanced rectal cancer, including total neoadjuvant methods, protocols for radiation delivery, chemotherapy regimen and efforts to add novel targeted therapies, selective withdrawal of surgery or radiotherapy, and future perspectives. Moreover, we highlight relevant issues that have emerged with these new treatment possibilities.

The Budget Impact of Monoclonal Antibodies Used to Treat Metastatic Colorectal Cancer in Minas Gerais, Brazil

INTRODUCTION

Biological medicines have increased the cost of cancer treatments, which also raises concerns about sustainability. In Brazil, three monoclonal antibodies (mAbs)-bevacizumab, cetuximab, and panitumumab-are indicated for the treatment of metastatic colorectal cancer (mCRC) but not currently funded by the Unified Health System (SUS). However, successful litigation has led to funding in some cases.

OBJECTIVE

Our objective was to evaluate the budgetary impact of including the mAbs bevacizumab, cetuximab, and panitumumab in standard chemotherapy for the treatment of mCRC within the SUS of Minas Gerais (MG), Brazil.

METHOD

A budget impact analysis of incorporating mAbs as first-line treatment of mCRC in MG was explored. The perspective taken was that of the Brazilian SUS, and a 5-year time horizon was applied. Data were collected from lawsuits undertaken between January 2009 and December 2016, and the model was populated with data from national databases and published sources. Costs are expressed in $US.

RESULTS

In total, 351 lawsuits resulted in funding for first-line treatment with mAbs for mCRC. The three alternative scenarios analyzed resulted in cost increases of 348-395% compared with the reference scenario. The use of panitumumab had a budgetary impact of $US103,360,980 compared with the reference scenario over a 5-year time horizon, and bevacizumab and cetuximab had budgetary impacts of $US111,334,890 and 113,772,870, respectively. The use of the anti-epidermal growth factor receptor (EGFR) mAbs (cetuximab and panitumumab) is restricted to the approximately 41% of patients with KRAS mutations, so the best cost alternative for incorporation would be the combination of panitumumab and bevacizumab, with a cost of approximately $US106 million.

CONCLUSION

These results highlight the appreciable costs for incorporating bevacizumab, cetuximab, and panitumumab into the SUS. Appreciable discounts are likely to be necessary before incorporation of these mAbs is approved.

A Rare BRAF Fusion in Advanced Rectal Cancer Treated with Anti-Epidermal Growth Factor Receptor Therapy

Recently, v-raf murine sarcoma viral oncogene homologue B (BRAF) fusions have been identified in multiple cancer types using comprehensive genomic profiling (CGP) assays. BRAF fusions are extremely rare, occurring in <0.5% of patients with metastatic colorectal cancer (mCRC). Until now, there is no standard treatment for mCRC with BRAF fusions. Here, we report a recurrent colorectal cancer case that harbored an EXOC4-BRAF fusion. A 40-year-old female patient with a 2-year history of type 2 diabetes was diagnosed with pathologically confirmed stage IV rectal adenocarcinoma with liver metastasis. She underwent R0 resection after neoadjuvant therapy; however, her disease recurred at multiple metastatic sites (lymph nodes, ovary, and peritoneal gland). A rectal cancer surgical specimen was submitted for CGP (Foundation One) to identify potential targets to develop treatment strategies. An EXOC4-BRAF fusion was identified, and she achieved partial response to FOLFOX + panitumumab which is a fully human antibody directed against epidermal growth factor receptor. No EXOC4-BRAF fusions in colorectal cancer cases have been reported to date. Further studies investigating molecular mechanisms and novel targeted therapy approaches are required.

Irinotecan or Oxaliplatin: Which is the First Move for the Mate?

OBJECTIVES

The aim of the present review is to discuss the potential link between RAS, BRAF and microsatellite instability (MSI) mutational patterns and chemotherapeutic agent efficacy [Irinotecan (IRI) vs. Oxaliplatin (OXA)], and how this can potentially influence the choice of the chemotherapy backbone.

METHODS

Following a review of the research literature, all pertinent articles published in the core journals were selected for the study. The inclusion criteria regarded relevant clinical and pre-clinical studies on the topic of interest (Relationship of OXA and IRI to KRAS/BRAF mutations and MSI).

RESULTS

Excision repair cross complementation group 1 (ERCC1) expression is inhibited by KRAS mutation, making tumor cells more sensitive to OXA. Results from OPUS, COIN and PRIME trials support that no conclusive data are available for BRAF mutant population because of the small number of patients. Enhanced IRI cytotoxicity to MSI cell lines is due to the participation of some of the mismatch repair (MMR) components in various DNA repair processes and their role in the maintenance of the pro-apoptotic effect of IRI and G2/M cell arrest.

CONCLUSION

OXA and IRI are indispensable drugs for mCRC treatment and their selection must be as careful as that of targeted agents. We suggest taking into consideration the interaction between known genomic alterations and OXA and IRI activity to personalize chemotherapy in mCRC patients.

Up-to-date role of aflibercept in the treatment of colorectal cancer

Introduction: Colorectal cancer (CRC) is a major public health problem. Despite major progress understanding the biological basis of this tumor added to the incorporation of optimized diagnostic and therapeutic strategies, prognosis after progression on first-line standard treatment remains poor. Several antiangiogenic treatments have demonstrated improvement in overall survival (OS) in the second-line treatment being aflibercept, a fully humanized recombinant protein, one of them. The results of the VELOUR study showed that the addition of aflibercept to second-line FOLFIRI improved OS and progression-free survival.Areas covered: A literature review of published clinical studies was performed in order to discuss the clinical data on aflibercept in mCRC from early drug development to real-world data.Expert opinion: The combination of aflibercept with FOLFIRI provides a statistical improvement in OS and in all the efficacy endpoints analyzed in the VELOUR trial, showing efficacy independently on time to progression, molecular status, prior biological treatment, or age. Further studies are needed to find new biomarkers and molecular characterization in order to better select patients that could benefit from this treatment.

CYTOPLASMIC-MEMBRANE EGFR PREDICTS EXPANDED RAS MUTATION STATUS IN COLORECTAL CARCINOMAS?

BACKGROUND

Inhibitors of the epidermal growth factor (EGFR) represent an effective therapeutic option for patients with metastatic colorectal carcinoma, free of activating mutations in KRAS and NRAS. However, the research of mutations is of high cost and scarcely accessible. The expression of the EGFR by immunohistochemistry predicting the mutation status of the expanded RAS (KRAS and NRAS), may allow treatment by a diagnostic method less costly and more accessible.

AIM

Investigate the correlation between the clinical-pathological data, the cytoplasmic-membrane expression of the EGFR and the mutational status of the expanded RAS.

METHOD

A total of 139 patients with colorectal carcinoma from the archives of Instituto Goiano de Oncologia e Hematologia were evaluated.

RESULTS

Mutation of the expanded RAS was detected in 78 (56.1%) cases. The EGFR expression was stratified in 23 (16.5%) "positive", 49 (35.2%) "negative" and 67 (48.2%) "uncertain". No significant correlation was found between the mutational status of the RAS and the EGFR expression in comparison to age, gender, location, histological type, histological grade and stage. From 23 "positive" cases, 21 (91.3%) showed wild-type RAS gene, and 49 "negative", 41 (83.7%) presented mutation, resulting in a strong association between EGFR "positive", "negative" groups and the mutational status of the RAS (p<0.001), with 86.1% of accuracy.

CONCLUSIONS

The cytoplasmic-membrane analysis of the EGFR expression stratified into "positive", "negative" and "uncertain" predicts mutational status of the RAS in 51.7% of the cases (p<0.001), with 86.1% of accuracy.

Genomic Sequencing and Insight into Clinical Heterogeneity and Prognostic Pathway Genes in Patients with Metastatic Colorectal Cancer

BACKGROUND

An understanding of signaling pathways has not been fully incorporated into prognostication and therapeutic options. We evaluated the hypothesis that information about cancer-related signaling pathways can improve prognostic stratification and explain some of the clinical heterogeneity in patients with metastatic colorectal cancer.

STUDY DESIGN

We analyzed prognostic relevance of signaling pathways in patients undergoing resection of colorectal liver metastases (CLM) from 2004-2017, and clinical actionability of gene alterations in 7 signaling pathways: p53, Wnt, RTK-RAS, PI3K, TGFβ, Notch, and cell cycle. To assess the wide applicability, the results were validated in an external retrospective cohort including patients with unresectable metastatic colorectal cancer.

RESULTS

Of 579 patients, the numbers of patients with pathway alterations were as follows: p53, n = 420 (72.5%); Wnt, 340 (58.7%); RTK-RAS, 333 (57.5%); PI3K, 110 (19.0%); TGFβ, 65 (11.2%); Notch, 41 (7.1%); and cell cycle, 15 (2.6%). More than 80% of alterations in each pathway occurred in a single predominant gene TP53, APC, KRAS, PIK3CA, FBXW7, and RB1 in p53, Wnt, RTK-RAS, PI3K, Notch, and cell cycle pathways, respectively. Alterations of 4 pathways (p53, RTK-RAS, TGFβ, and Notch) and corresponding predominant genes (TP53, RAS/BRAF, SMAD4, and FBXW7) were significantly associated with worse overall survival (OS), and alterations of Wnt pathway (APC) were associated with better OS in the median follow-up duration of 3.8 years. Similarly, in the external cohort, alterations of p53 (TP53) and RTK-RAS (RAS/BRAF) were significantly associated with worse OS, whereas alteration of Wnt (APC) was associated with better OS in the median follow-up duration of 2.6 years.

CONCLUSIONS

Genomic sequencing provides insights into clinical heterogeneity and permits finer prognostic stratification in patients with metastatic colorectal cancer.

The Screening and COnsensus Based on Practices and Evidence (SCOPE) Program-Results of a Survey on Daily Practice Patterns for Patients with mCRC

The SCOPE project aimed to better understand practice patterns, identify drivers for treatment goals, and determine third- and fourth-line treatment choices for patients with metastatic colorectal cancer (mCRC). The survey was developed by an expert panel of gastrointestinal oncologists. Questions concerned general practice patterns, and treatment decisions for three hypothetical patient case scenarios. Participants had to routinely manage patients with mCRC. We present results from 629 participants who provided input on patient treatment scenarios (data cutoff: 17/01/2020). Prolonging overall survival (OS; 51%) was the main aim in first line. In third line, quality of life (QOL) was the primary goal (34%). Forty-three percent also cited efficacy-focused goals; 18% and 13% noted prolonging OS and improving progression-free survival as main aims, respectively. For fit and active patients, 89% of respondents considered trifluridine-tipiracil an appropriate third-line treatment; regorafenib (31%) or clinical trial enrollment (29%) were the fourth-line options. For patients with comorbidities and limited caregiver support, trifluridine-tipiracil was the preferred third-line treatment (70%). For KRAS-mutated patients with comorbidities and adverse events who received prior oxaliplatin, 90% considered oxaliplatin rechallenge an unsuitable third-line treatment, mainly due to the risk of cumulative toxicity (75%). In the third/fourth-line settings, trifluridine-tipiracil followed by regorafenib was the most common option (54%); 17% chose regorafenib followed by trifluridine-tipiracil. Efficacy coupled with QOL are important goals in third-line treatment. Daily practice patterns reflect the guideline recommendations in third- and fourth-line settings, with a trend toward using trifluridine-tipiracil versus regorafenib in KRAS-wildtype and KRAS-mutant tumors.

Treatment sequencing of metastatic colorectal cancer based on primary tumor location

Colorectal cancer is a heterogeneous disease with various clinical, molecular, and embryological differences related to the origin of the tumor from the right or left colon. Recent studies have demonstrated that tumor sidedness has both a prognostic and predictive value in metastatic colorectal cancer . Patients whose primary tumor originates from the left side of the colon and whose tumor's genome encodes wild-type RAS and BRAF should be offered cetuximab or panitumumab in the first-line treatment of metastatic disease or in subsequent lines. For tumors originating from the right side of the colon, anti-angiogenic treatment, particularly bevacizumab, is an option for this poor prognostic group until better options become available. Specifically, an aggressive initial approach with FOLFOXIRI plus bevacizumab is a treatment option in right-sided tumors under investigation. This report reviews the available data for the treatment of metastatic colorectal cancer according to the location of the primary tumor and proposes the optimal treatment sequencing strategy incorporating the site of origin of the tumor and molecular information into the decision-making process.

Shared decision-making and patient decision aids in choosing first-line targeted therapy for metastatic colorectal cancer in Taiwan

INTRODUCTION

In Taiwan, given the discrepancy between current treatment guidelines and reimbursement options, patients might require a tool to support their decision-making process when selecting a regimen for metastatic colorectal cancer, especially therapeutic strategies, and subsequent costs, along with efficacy and safety outcomes. Therefore, we developed a patient decision aid (PDA) to support patients in choosing between treatment options recommended based on the current evidence and those reimbursed by the Taiwanese National Health Insurance.

METHODS

By carefully reviewing the updated data and then interpreting the clinical tool, we conducted a needs assessment using a serial questionnaire to test for a step-by-step adjustment of the PDA.

RESULTS

Patients, their relatives, and medical team members were most concerned about outcomes, such as overall survival, progression-free survival, objective response rate, tumor shrinkage to resectable status, total medical cost, severe gastrointestinal perforation, and severe skin reaction. After a serial alpha test for quality, we performed quantitative evaluation and beta tests, revealing average scores of more than 4 points (on a scale of 1-5) for both perceptibility and utility.

CONCLUSIONS

The present findings suggest that PDAs are useful and supplement the shared decision-making practice, helping patients make decisions about preferences and consider the pros and cons of treatment regimens, along with insurance reimbursement options.

Metastatic colo-rectal cancer: real life experience from an Indian tertiary care center

Background

No data exist for the long-term outcome of metastatic colorectal cancer (mCRC) from the Southern part of Asia. The primary objective of the study is to evaluate the survival outcome of mCRC from an Indian tertiary care center. The study also aims to highlight the treatment pattern practiced and the unique clinico-pathologic characteristics.

Methods

This is a single-center retrospective observational study done at a large referral tertiary care center in North India. All patients with synchronous or metachronous mCRC who received at least one dose of chemotherapy for metastatic disease, registered between 2003 to 2017 were included. Primary outcome measures were overall survival and progression-free survival and prognostic factors of overall survival. Descriptive analysis was done for the clinicopathological characteristics and treatment patterns. Kaplan Meier method for overall survival and progression-free survival. Cox regression analysis was performed for the determination of the prognostic factors for overall survival.

Result

Out of 377 eligible patients, 256 patients (68%) had de novo metastatic disease and the remaining 121 (32%) progressed to metastatic disease after initial treatment. The cohort was young (median age, 46 years) with the most common primary site being the rectum. A higher proportion of signet (9%) and mucinous histology (24%). The three common sites of metastasis were the liver, peritoneum, and lung. In the first line, most patients received oxaliplatin-based chemotherapy (70%). Only 12.5% of patients received biologicals in the first-line setting. The median follow-up and median overall survival of study cohort were 17 months and 18.5 months. The factors associated with poor outcome for overall survival on multivariate analysis were ECOG performance status of > 1, high CEA, low albumin, and the number of lines of chemotherapy received (< 2).

Conclusion

The outcome of mCRC is inferior to the published literature. We found a relatively higher proportion of patients with the following characteristics; younger, rectum as primary tumor location, the signet, and mucinous histology, higher incidence of peritoneum involvement. The routine use of targeted therapies is limited. Government schemes (inclusion of targeted therapies in the Ayushman scheme), NGO assistance, and availability of generic low-cost targeted drugs may increase the availability.

NMR Profiling of Ononis diffusa Identifies Cytotoxic Compounds against Cetuximab-Resistant Colon Cancer Cell Lines

In the search of new natural products to be explored as possible anticancer drugs, two plant species, namely Ononis diffusa and Ononis variegata, were screened against colorectal cancer cell lines. The cytotoxic activity of the crude extracts was tested on a panel of colon cancer cell models including cetuximab-sensitive (Caco-2, GEO, SW48), intrinsic (HT-29 and HCT-116), and acquired (GEO-CR, SW48-CR) cetuximab-resistant cell lines. Ononis diffusa showed remarkable cytotoxic activity, especially on the cetuximab-resistant cell lines. The active extract composition was determined by NMR analysis. Given its complexity, a partial purification was then carried out. The fractions obtained were again tested for their biological activity and their metabolite content was determined by 1D and 2D NMR analysis. The study led to the identification of a fraction enriched in oxylipins that showed a 92% growth inhibition of the HT-29 cell line at a concentration of 50 µg/mL.

Acquired resistance to third-generation EGFR-TKIs and emerging next-generation EGFR inhibitors

The discovery that mutations in the EGFR gene are detected in up to 50% of lung adenocarcinoma patients, along with the development of highly efficacious epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), has revolutionized the treatment of this frequently occurring lung malignancy. Indeed, the clinical success of these TKIs constitutes a critical milestone in targeted cancer therapy. Three generations of EGFR-TKIs are currently approved for the treatment of EGFR mutation-positive non-small cell lung cancer (NSCLC). The first-generation TKIs include erlotinib, gefitinib, lapatinib, and icotinib; the second-generation ErbB family blockers include afatinib, neratinib, and dacomitinib; whereas osimertinib, approved by the FDA on 2015, is a third-generation TKI targeting EGFR harboring specific mutations. Compared with the first- and second-generation TKIs, third-generation EGFR inhibitors display a significant advantage in terms of patient survival. For example, the median overall survival in NSCLC patients receiving osimertinib reached 38.6 months. Unfortunately, however, like other targeted therapies, new EGFR mutations, as well as additional drug-resistance mechanisms emerge rapidly after treatment, posing formidable obstacles to cancer therapeutics aimed at surmounting this chemoresistance. In this review, we summarize the molecular mechanisms underlying resistance to third-generation EGFR inhibitors and the ongoing efforts to address and overcome this chemoresistance. We also discuss the current status of fourth-generation EGFR inhibitors, which are of great value in overcoming resistance to EGFR inhibitors that appear to have greater therapeutic benefits in the clinic.

•

EGFR gene mutations are detected in about 50% of non-small cell lung cancer (NSCLC) patients worldwide

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The three generations of EGFR tyrosine kinase inhibitors (TKIs) are critical milestones for NSCLC patients

•

Like other targeted therapies, new EGFR mutations and coupled drug resistances emerge rapidly after TKI treatment, posing formidable obstacles to cancer management

•

The investigational fourth-generation EGFR inhibitors are of great promise, through a number of novel mechanisms, in overcoming these resistances after third-generation TKI treatment, and will bring more benefits to NSCLC patients

Clinical characteristics and prognostic value of the KRAS mutation in Chinese colorectal cancer patients

BACKGROUND

The KRAS mutations are high-frequency somatic mutations found in colorectal cancer patients from Western and Asian countries however, with the exception of exon 2 of KRAS, other prevalence and prognostic values have not been adequately assessed in Asian patients. The aim of this study was to determine the mutation frequencies of whole exon mutations of KRAS in Chinese colorectal cancer patients and to investigate their impact on prognosis.

METHODS

A total of 7189 tumor tissue samples (iCohort) were subjected to next-generation sequencing for detection of KRAS mutations. All pathologic or likely pathologic mutations of KRAS were considered. In addition, clinical features and prognostic dates were collected from 145 patients at The Third Affiliated Hospital of Soochow University, China (sCohort) and used droplet digital™ polymerase chain reaction to detect KRAS mutations.

RESULTS

In the iCohort, 2706 patients (37.6%) were confirmed harboring KRAS mutations. The most frequent of these mutations were G12D (32.19%), G12V (17.96%), and G13D (17.59%). In the sCohort, 51 colorectal cancer patients (35.17%) had KRAS mutations, among which KRAS G12D (64.71%), G13D (29.41%), and G14D (3.92%) were high-frequency. The KRAS mutations were associated with shorter median overall survival than wild-type tumors (69 vs. 55 months; HR 1.80; 95% Cl 1.22, 2.64; P=0.0003). In the Cox multivariate analysis, age (HR 1.562; 95% Cl 1.10, 2.22; P=0.013), tumor differentiation (HR 0.417; 95% Cl 0.19, 0.90; P=0.026), and KRAS mutation (HR 1.897; 95% Cl 0.19, 0.90; P=0.001) remained independent predictors of shorter overall survival. Among the common KRAS mutations, G12D was significantly associated with shorter overall survival (HR 2.17; 95% Cl 1.31, 3.58; P < 0.0001) compared with KRAS wild-type patients.

CONCLUSIONS

Our findings indicate that KRAS genes are frequently mutated, and over 30% harbored the KRAS G12D mutation subtype. We found that the KRAS G12D mutation is associated with inferior survival and is a biomarker of poor prognosis in Chinese patients. Our data emphasize the importance of molecular features in colorectal cancer patients, which could potentially be improved by G12D-specific related inhibitors.

Clinical and prognostic features of patients with detailed RAS/BRAF-mutant colorectal cancer in Japan

Background

RAS/BRAF^V600E mutations are the most remarkable oncogenic driver mutations in colorectal cancer (CRC) and play an important role in treatment selection. No data are available regarding the clinical and prognostic features of patients with detailed RAS/BRAF^V600E-mutant metastatic CRC (mCRC) in Japan.

Methods

A total of 152 chemotherapy-naïve patients with mCRC were included in this study between August 2018 and July 2019. Tumor samples were collected, and RAS/BRAF^V600E status was investigated. RAS/BRAF^V600E status was examined using a MEBGEN RASKET-B kit and polymerase chain reaction reverse sequence-specific oligonucleotide method.

Results

RAS/BRAF^V600E mutations were detected in 54% of cases (KRAS codon 12, 26%; KRAS codon 13, 17%; KRAS non-Exon2, 5%; NRAS, 5%; and BRAF^V600E, 7%). BRAF^V600E-mutant CRC mainly existed in the right colon, whereas KRAS non-Exon2 and NRAS-mutant CRC was predominantly present in the left colon. KRAS non-Exon2 and NRAS-mutant CRC were associated with shorter survival time than RAS wild-type CRC (hazard ratio [HR], 2.26; 95% confidence interval [CI], 0.64–8.03; p = 0.19; HR, 2.42; 95% CI, 0.68–8.61; p = 0.16) and significantly shorter overall survival than KRAS Exon2-mutant CRC (HR, 3.88; 95% CI, 0.92–16.3; p = 0.04; HR, 4.80; 95% CI, 1.14–20.2; p = 0.02).

Conclusions

In our multicenter study, the findings elucidated the clinical and prognostic features of patients with detailed RAS/BRAF^V600E-mutant mCRC in Japan.

Metastatic colorectal cancer: Advances in the folate-fluoropyrimidine chemotherapy backbone

Notwithstanding recent treatment advances in metastatic colorectal cancer (mCRC), chemotherapy with a combination of a fluoropyrimidine and a folate agent, often 5-fluorouracil (5-FU) and leucovorin, remains the backbone of treatment regimens for the majority of patients with mCRC. This is despite a recent focus on molecular-targeted treatments and patient stratification according to mutational status or expression levels of specific genes. Intracellular folate concentration was discovered to be pivotal in the cytotoxic efficacy of 5-FU, paving the way to the current standard combination therapy approach. Subsequent discovery that systemic chemotherapy agents, such as irinotecan and oxaliplatin, can further increase the efficacy of 5-FU-based treatments led to the development of several combination chemotherapy regimens, including FOLFOX, FOLFIRI and FOLFOXIRI. Subsequent efforts to optimise 5-FU-based treatments have focused on 5-FU analogues, initially capecitabine and the combination drug tegafur/gimeracil/oteracil (S-1) and then TAS-102, which has recently been evaluated in phase 3 clinical trials for refractory colorectal cancer. Further approaches taken to improve the efficacy of 5-FU chemotherapy regimens have focused on optimising the route and dosing schedules and regulating folate metabolism. Pharmacokinetic variability caused by the requirement for metabolic conversion of leucovorin has been central to recent research, and the development of agents such as arfolitixorin which bypass the need for metabolic conversion remains promising for future therapeutic candidates. In this review, we summarise the evidence leading to the current treatment regimens employing 5-FU and leucovorin, focusing on recent approaches taken to optimise and refine treatments to improve clinical outcomes in patients with mCRC.

The effect of aflibercept and arsenic trioxide on the proliferation, migration and apoptosis of oral squamous cell carcinoma in vitro

Aflibercept and arsenic trioxide drugs apply a cytotoxic effect on some human cancer cell lines. However, no more study has followed the effects of both drugs, especially arsenic trioxide, on oral squamous cell carcinoma (OCC). We used three OCC lines as a model to show the effect of these drugs on the genetically complex disease and investigate its targeted therapy. In this study, three human OCC cell lines were used from different patients. We treated cell lines with both medications to detect the effect and relevant molecular basis. First, methyl thiazolyl tetrazolium (MTT) assay was performed to detect the cytotoxicity effect and cell growth. Second, flow cytometry, gene and protein expression were performed to evaluate the anti-angiogenic effect on OCC lines. Next apoptosis was analyzed by flow cytometry. Finally, clonogenesis capacity and cell migration were assessed by colony formation assay and wound healing, respectively. Aflibercept had no cytotoxic effect on the three OCC cell lines but decreased cell growth rate. Arsenic trioxide had a significant cytotoxic effect on three cell lines. Our results demonstrated that both drugs significantly decreased endoglin, VEGFA, and VEGFB expression. In addition, Migration and colony formation assays confirmed that these drugs have significant anti-proliferative and anti-migration effect on oral carcinoma cells. These results revealed that both medications might be a potential drug for the management of oral cancer patients.

Failure to Cure Patients with Colorectal Liver Metastases: The Impact of the Liver Surgeon

BACKGROUND

Lack of a liver surgeon (LS) may lead to failure to cure in patients with possibly resectable colorectal liver metastases (CRLM). This study aims to quantify the failure-to-cure rate due to noninclusion of an LS.

PATIENTS AND METHODS

All patients who underwent chemotherapy with palliative intent for CRLM at a community oncology network between 2010 and 2018 were identified from a prospectively maintained cancer registry. Two LS blinded to patient management and outcome reviewed pretreatment imaging and assigned each scan a newly developed resectability score. Nominal group technique and independent scores were combined to determine probability of curative-intent resection. Interobserver agreement was calculated using κ testing.

RESULTS

This study included 72 palliative CRLM patients. Demographic factors were: 44 (59%) male, median age 68 years (range 36-94 years), 23 (32%) rectal primary, 24 (33%) receiving oxaliplatin-based chemotherapy. Of the 72 patients with CRLM, 6 had left-sided metastases only. The median number of CRLM was 6 (1-8). Agreement on resectability was achieved in 32 (44%) patients for the entire cohort and 17 (54%) in patients without extrahepatic disease. A lower median number of CRLM was found in the group considered to be resectable by the two LS (2 versus 8; p = 0.001). Substantial agreement was found between liver surgeons in the group of patients without extrahepatic disease (κ = 0.9043).

CONCLUSIONS

Over 44% of patients who were assigned palliative chemotherapy at tumor boards without an LS were considered potentially resectable upon independent LS review.

Radiomics Response Signature for Identification of Metastatic Colorectal Cancer Sensitive to Therapies Targeting EGFR Pathway

BACKGROUND

The authors sought to forecast survival and enhance treatment decisions for patients with liver metastatic colorectal cancer by using on-treatment radiomics signature to predict tumor sensitiveness to irinotecan, 5-fluorouracil, and leucovorin (FOLFIRI) alone (F) or in combination with cetuximab (FC).

METHODS

We retrospectively analyzed 667 metastatic colorectal cancer patients treated with F or FC. Computed tomography quality was classified as high (HQ) or standard (SD). Four datasets were created using the nomenclature (treatment) - (quality). Patients were randomly assigned (2:1) to training or validation sets: FCHQ: 78:38, FCSD: 124:62, FHQ: 78:51, FSD: 158:78. Four tumor-imaging biomarkers measured quantitative radiomics changes between standard of care computed tomography scans at baseline and 8 weeks. Using machine learning, the performance of the signature to classify tumors as treatment sensitive or treatment insensitive was trained and validated using receiver operating characteristic (ROC) curves. Hazard ratio and Cox regression models evaluated association with overall survival (OS).

RESULTS

The signature (area under the ROC curve [95% confidence interval (CI)]) used temporal decrease in tumor spatial heterogeneity plus boundary infiltration to successfully predict sensitivity to antiepidermal growth factor receptor therapy (FCHQ: 0.80 [95% CI = 0.69 to 0.94], FCSD: 0.72 [95% CI = 0.59 to 0.83]) but failed with chemotherapy (FHQ: 0.59 [95% CI = 0.44 to 0.72], FSD: 0.55 [95% CI = 0.43 to 0.66]). In cetuximab-containing sets, radiomics signature outperformed existing biomarkers (KRAS-mutational status, and tumor shrinkage by RECIST 1.1) for detection of treatment sensitivity and was strongly associated with OS (two-sided P < .005).

CONCLUSIONS

Radiomics response signature can serve as an intermediate surrogate marker of OS. The signature outperformed known biomarkers in providing an early prediction of treatment sensitivity and could be used to guide cetuximab treatment continuation decisions.