Resectability and outcome with anti-EGFR agents in patients with KRAS wild-type colorectal liver-limited metastases: a meta-analysis

Tata Memorial Centre Evidence Based Management of Colorectal cancer

ABSTRACT

This review article examines the evidence-based management of colorectal cancers, focusing on topics characterized by ongoing debates and evolving evidence. To contribute to the scientific discourse, we intentionally exclude subjects with established guidelines, concentrating instead on areas where the current understanding is dynamic. Our analysis encompasses a thorough exploration of critical themes, including the evidence surrounding complete mesocolic excision and D3 lymphadenectomy in colon cancers. Additionally, we delve into the evolving landscape of perioperative chemotherapy in both colon and rectal cancers, considering its nuanced role in the context of contemporary treatment strategies. Advancements in surgical techniques are a pivotal aspect of our discussion, with an emphasis on the utilization of minimally invasive approaches such as laparoscopy and robotic surgery in both colon and rectal cancers, including advanced rectal cases. Moving beyond conventional radical procedures, we scrutinize the feasibility and implications of endoscopic resections for small tumors, explore the paradigm of organ preservation in locally advanced rectal cancers, and assess the utility of total neoadjuvant therapy in the current treatment landscape. Our final segment reviews pivotal trials that have significantly influenced the management of colorectal liver and peritoneal metastasis.

Optimizing Treatment Strategy for Oligometastases/Oligo-Recurrence of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer, and nearly half of CRC patients experience metastases. Oligometastatic CRC represents a distinct clinical state characterized by limited metastatic involvement, demonstrating a less aggressive nature and potentially improved survival with multidisciplinary treatment. However, the varied clinical scenarios giving rise to oligometastases necessitate a precise definition, considering primary tumor status and oncological factors, to optimize treatment strategies. This review delineates the concepts of oligometastatic CRC, encompassing oligo-recurrence, where the primary tumor is under control, resulting in a more favorable prognosis. A comprehensive examination of multidisciplinary treatment with local treatments and systemic therapy is provided. The overarching objective in managing oligometastatic CRC is the complete eradication of metastases, offering prospects of a cure. Essential to this management approach are local treatments, with surgical resection serving as the standard of care. Percutaneous ablation and stereotactic body radiotherapy present less invasive alternatives for lesions unsuitable for surgery, demonstrating efficacy in select cases. Perioperative systemic therapy, aiming to control micrometastatic disease and enhance local treatment effectiveness, has shown improvements in progression-free survival through clinical trials. However, the extension of overall survival remains variable. The review emphasizes the need for further prospective trials to establish a cohesive definition and an optimized treatment strategy for oligometastatic CRC.

Chemotherapy Duration for Various Indications in Colorectal Cancer: a Review

PURPOSE OF REVIEW

The treatment of colorectal cancer (CRC) has evolved and become more personalized during the past several years. For example, depotentiation/reduced duration of systemic therapies has proven to be beneficial in both advanced and early stages of the disease.

RECENT FINDINGS

In particular, recent randomized studies of stage III and high-risk stage II CRC showed that a shorter duration (3 months), when compared to the historical 6-month comparator, provides nearly similar overall survival (OS) and disease-free survival (DFS). In the setting of advanced, inoperable CRC, a relatively short induction phase (six to eight cycles) followed by biological agents is the current standard of care in RAS wild-type (wt). versus RAS mutated cases. With regard to potentially operable stage IV disease (with the aim of converting liver metastases to operability), a relatively short number of cycles (four to six cycles) should be offered with re-staging and re-evaluation for surgery as soon as possible in most cases. For inoperable liver metastases, a relatively intensive triplet or doublet plus targeted therapy may attain conversion in some cases and may even result in cure. Rectal cancer treatment continues to be a complex disease in terms of treatment and oncological results. Recent data seem to showcase the benefits of more prolonged sequential strategies (total neoadjuvant therapy, all treatment delivered before surgery, to reduce the risk of distant metastases and local control). In recent years, different strategies regarding treatment intensity have been employed in CRC in adjuvant and metastatic setting. Introduction of triplets as first-line therapy for colon cancer and as induction phase for rectal cancer are now therapeutic options. Conversely in stage II disease or low-risk stage III resected CRC, a reduced chemotherapy length is a new standard of care.

The Impact of Molecular Biology in the Seeding, Treatment Choices and Follow-Up of Colorectal Cancer Liver Metastases-A Narrative Review

There is a clear association between the molecular profile of colorectal cancer liver metastases (CRCLM) and the degree to which aggressive progression of the disease impacts patient survival. However, much of our knowledge of the molecular behaviour of colorectal cancer cells comes from experimental studies with, as yet, limited application in clinical practice. In this article, we review the current advances in the understanding of the molecular behaviour of CRCLM and present possible future therapeutic applications. This review focuses on three important steps in CRCLM development, progression and treatment: (1) the dissemination of malignant cells from primary tumours and the seeding to metastatic sites; (2) the response to modern regimens of chemotherapy; and (3) the possibility of predicting early progression and recurrence patterns by molecular analysis in liquid biopsy.

Oncologic aspects of the decision-making process for surgical approach for colorectal liver metastases progressing during chemotherapy

Colorectal cancer represents the third most diagnosed malignancy in the world. The liver is the main site of metastatic disease, affected in 30% of patients with newly diagnosed disease. Complete resection is considered the only potentially curative treatment for colorectal liver metastasis (CRLM), with a 5-year survival rate ranging from 35% to 58%. However, up to 80% of patients have initially unresectable disease, due to extrahepatic disease or bilobar multiple liver nodules. The availability of increasingly effective systemic chemotherapy has contributed to converting patients with initially unresectable liver metastases to resectable disease, improving long-term outcomes, and accessing tumor biology. In recent years, response to preoperative systemic chemotherapy before liver resection has been established as a major prognostic factor. Some studies have demonstrated that patients with regression of hepatic metastases while on chemotherapy have improved outcomes when compared to patients with stabilization or progression of the disease. Even if disease progression during chemotherapy represents an independent negative prognostic factor, some patients may still benefit from surgery, given the role of this modality as the main treatment with curative intent for patients with CRLM. In selected cases, based on size, the number of lesions, and tumor markers, surgery may be offered despite the less favorable prognosis and as an option for non-chemo responders.

Surgical Therapy in Patients with Colorectal Liver Metastases

BACKGROUND

Liver metastases (LM) occur in about 50% of patients with colorectal cancer. Besides the multimodal treatment of the primary tumor, the only way to cure patients with colorectal LM (CRLM) is complete resection. Different surgical procedures for this purpose are available depending on location, size, and number of LM. Additional concepts for patients with primary unresectable LM exist, ranging from Chemotherapy to induction of liver hypertrophy and even liver transplantation. This review intends to provide an overview of the surgical approach.

SUMMARY

Surgical options in the treatment of CRLM are defined and limited by their intraparenchymal location and their proximity to major vessels and intrahepatic bile ducts. Lesions located in the periphery can be excised in a parenchymal sparing fashion with a small tumor-surrounding resection margin of healthy liver parenchyma. If this is not possible, anatomical resections based on segmental boundaries are performed. In these cases, a sufficient functional volume of liver parenchyma after resection (future liver remnant volume [FLRV]) has to be preserved. This FLRV depends on various factors such as bodyweight and possible preexisting liver damage, such as cirrhosis, fibrosis, or chemotherapy-induced liver impairment. Liver hypertrophy via partial occlusion of the portal venous system is a standard procedure for patients with primary unresectable LM to increase FLRV. Furthermore, discussion of liver transplantation in cases of unresectable LM is gaining importance again. A combination of surgery and adjuvant and/or neoadjuvant chemotherapy may be indicated in individual cases, but general evidence-based recommendations cannot be given without further studies.

KEY MESSAGES

Surgical removal of all metastases represents the only option of a potentially curative treatment of UICC stage IV colorectal carcinoma with liver involvement. An interdisciplinary approach consisting of chemotherapeutical downsizing and hypertrophy of the FLRV offers potential curative treatment for patients with initially unresectable metastases. For all others, liver transplantation is seeing a revival showing promising results in overall survival compared to chemotherapy alone.

Is precision medicine for colorectal liver metastases still a utopia? New perspectives by modern biomarkers, radiomics, and artificial intelligence

The management of patients with liver metastases from colorectal cancer is still debated. Several therapeutic options and treatment strategies are available for an extremely heterogeneous clinical scenario. Adequate prediction of patients’ outcomes and of the effectiveness of chemotherapy and loco-regional treatments are crucial to reach a precision medicine approach. This has been an unmet need for a long time, but recent studies have opened new perspectives. New morphological biomarkers have been identified. The dynamic evaluation of the metastases across a time interval, with or without chemotherapy, provided a reliable assessment of the tumor biology. Genetics have been explored and, thanks to their strong association with prognosis, have the potential to drive treatment planning. The liver-tumor interface has been identified as one of the main determinants of tumor progression, and its components, in particular the immune infiltrate, are the focus of major research. Image mining and analyses provided new insights on tumor biology and are expected to have a relevant impact on clinical practice. Artificial intelligence is a further step forward. The present paper depicts the evolution of clinical decision-making for patients affected by colorectal liver metastases, facing modern biomarkers and innovative opportunities that will characterize the evolution of clinical research and practice in the next few years.

Liver regeneration biology: Implications for liver tumour therapies

The liver has remarkable regenerative potential, with the capacity to regenerate after 75% hepatectomy in humans and up to 90% hepatectomy in some rodent models, enabling it to meet the challenge of diverse injury types, including physical trauma, infection, inflammatory processes, direct toxicity, and immunological insults. Current understanding of liver regeneration is based largely on animal research, historically in large animals, and more recently in rodents and zebrafish, which provide powerful genetic manipulation experimental tools. Whilst immensely valuable, these models have limitations in extrapolation to the human situation. In vitro models have evolved from 2-dimensional culture to complex 3 dimensional organoids, but also have shortcomings in replicating the complex hepatic micro-anatomical and physiological milieu. The process of liver regeneration is only partially understood and characterized by layers of complexity. Liver regeneration is triggered and controlled by a multitude of mitogens acting in autocrine, paracrine, and endocrine ways, with much redundancy and cross-talk between biochemical pathways. The regenerative response is variable, involving both hypertrophy and true proliferative hyperplasia, which is itself variable, including both cellular phenotypic fidelity and cellular trans-differentiation, according to the type of injury. Complex interactions occur between parenchymal and non-parenchymal cells, and regeneration is affected by the status of the liver parenchyma, with differences between healthy and diseased liver. Finally, the process of termination of liver regeneration is even less well understood than its triggers. The complexity of liver regeneration biology combined with limited understanding has restricted specific clinical interventions to enhance liver regeneration. Moreover, manipulating the fundamental biochemical pathways involved would require cautious assessment, for fear of unintended consequences. Nevertheless, current knowledge provides guiding principles for strategies to optimise liver regeneration potential.

Accuracy of Modern Clinical Risk Score Including RAS Status Changes Based on Whether Patients Received Perioperative Chemotherapy for Colorectal Liver Metastases

BACKGROUND

A modified Fong clinical score (m-Fong CS) that includes the RAS mutation status has recently been proposed and offered an improved survival stratification of patients who undergo surgery and systemic chemotherapy for colorectal liver metastases (CLM). The aim of this study is to assess whether a CS that includes RAS status is influenced by whether patients receive perioperative chemotherapy.

METHODS

We created a new CS using multivariate analysis of data of patients who underwent hepatectomy for CLM for the first time between 2010 and 2016 at a single hospital (n = 341, 79% received perioperative chemotherapy). The resulting CS and m-Fong CS were then validated in the patient cohort at three other hospitals (n = 309). Furthermore, the applicability of the two CS in the total cohort (n = 650) was tested according to whether the patients received perioperative chemotherapy.

RESULTS

The new CS comprised mutant RAS status, ≥4 CLMs, and a CA19-9 level ≥100 U/mL (1 point per factor). Both the new CS and m-Fong CS failed to stratify the survival of the 309 patients in the validation cohort, including those who did not receive perioperative chemotherapy (29%). Both of the CS accurately stratified the survival of patients who underwent perioperative chemotherapy but not of those who underwent surgery alone.

CONCLUSION

A CS that includes the RAS mutation status can stratify the survival of patients who undergo hepatectomy combined with perioperative chemotherapy, but it has limited value for patients who undergo surgery alone.

Conversion strategies with chemotherapy plus targeted agents for colorectal cancer liver-only metastases: A systematic review

BACKGROUND

There is no consensus on the optimal systemic conversion therapy in patients with unresectable colorectal cancer liver-only metastases (CRLM) to achieve a complete resection. Interpretation of trials is complicated by heterogeneity of patients caused by emerging prognostic and predictive characteristics, such as RAS/BRAF mutation status, lack of consensus on unresectability criteria and lack of data on clinical outcome of secondary resections. A systematic review was performed of characteristics of study populations and methodology of trials regarding patients with initially unresectable colorectal cancer liver-only metastases.

METHODS

Phase II/III randomised trials, published after 2008, regarding first-line systemic conversion therapy in patients or subgroups of patients with CRLM were included. Data on secondary resection outcomes were collected.

RESULTS

Overall, 20 trials were included for analysis: seven prospective trials in patients with unresectable CRLM and 13 trials in the overall population of unresectable metastatic colorectal cancer (mCRC) with retrospective subgroup analysis of CRLM patients. Fourteen trials did not provide unresectability criteria at baseline, and criteria differed among the remaining studies. Trials and study populations were heterogeneous in prognostic/predictive factors, use of primary end-points, and reporting on long-term clinical outcomes. R0-resection rates in CRLM patients varied between CRLM studies and mCRC studies, with rates of 22-57% and 11-38%, respectively.

CONCLUSIONS

Cross-study comparison of (subgroups of) studies regarding first-line systemic treatment in patients with unresectable CRLM is hampered by heterogeneity in study populations, trial designs, use of (K)RAS/BRAF mutational tumour status, and differences/absence of unresectability criteria. No optimal conversion systemic regimen can be selected from available data. Prospective studies with well-defined criteria of these issues are warranted.

Colorectal liver metastases: Current management and future perspectives

The liver is the commonest site of metastatic disease for patients with colorectal cancer, with at least 25% developing colorectal liver metastases (CRLM) during the course of their illness. The management of CRLM has evolved into a complex field requiring input from experienced members of a multi-disciplinary team involving radiology (cross sectional, nuclear medicine and interventional), Oncology, Liver surgery, Colorectal surgery, and Histopathology. Patient management is based on assessment of sophisticated clinical, radiological and biomarker information. Despite incomplete evidence in this very heterogeneous patient group, maximising resection of CRLM using all available techniques remains a key objective and provides the best chance of long-term survival and cure. To this end, liver resection is maximised by the use of downsizing chemotherapy, optimisation of liver remnant by portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy, and combining resection with ablation, in the context of improvements in the functional assessment of the future remnant liver. Liver resection may safely be carried out laparoscopically or open, and synchronously with, or before, colorectal surgery in selected patients. For unresectable patients, treatment options including systemic chemotherapy, targeted biological agents, intra-arterial infusion or bead delivered chemotherapy, tumour ablation, stereotactic radiotherapy, and selective internal radiotherapy contribute to improve survival and may convert initially unresectable patients to operability. Currently evolving areas include biomarker characterisation of tumours, the development of novel systemic agents targeting specific oncogenic pathways, and the potential re-emergence of radical surgical options such as liver transplantation.

The actual management of colorectal liver metastases

Colorectal cancer is one of the most frequent cancers in the world and between 50% and 60% of patients will develop colorectal liver metastases (CRLM) during the disease. There have been great improvements in the management of CRLM during the last decades. The combination of modern chemotherapeutic and biological systemic treatments with aggressive surgical resection strategies is currently the base for the treatment of patients considered unresectable until few years ago. Furthermore, several new treatments for the local control of CRLM have been developed and are now part of the arsenal of multidisciplinary teams for the treatment of these complex patients. The aim of this review was to summarize and update the management of CRLM, its controversies and relevant evidence.

Initial systemic chemotherapeutic and targeted therapy strategies for the treatment of colorectal cancer patients with liver metastases

Introduction: The liver is the most common metastatic site in colorectal cancer with more than half the patients developing a liver metastasis either at the time of their diagnosis (synchronous) or later (metachronous). Surgical resection remains the principal curative approach that offers significant survival improvements. However, upfront surgery is only possible in about 10-20% of patients at the time of diagnosis, making the consideration of other treatment modalities essential. Areas covered: In this review, the authors provide an overview of the standard approaches for the initial management of patients with colorectal cancer with liver metastases. They then provide an up-to-date discussion of first-line systemic chemotherapy/targeted therapy options in the contexts of initially resectable and unresectable disease and review toxicities and complications following these options. Expert opinion: Advances in chemotherapeutic agents and biological targeted therapies have improved the prognosis of colorectal cancer with liver metastases. However, there is still no 'single best approach', making further trials necessary to provide more evidence.

Colorectal liver metastases: An update on multidisciplinary approach

Liver metastasis is the commonest form of distant metastasis in colorectal cancer. Selection criteria for surgery and liver-directed therapies have recently been extended. However, resectability remains poorly defined. Tumour biology is increasingly recognized as an important prognostic factor; hence molecular profiling has a growing role in risk stratification and management planning. Surgical resection is the only treatment modality for curative intent. The most appropriate surgical approach is yet to be established. The primary cancer and the hepatic metastasis can be removed simultaneously or in a two-step approach; these two strategies have comparable long-term outcomes. For patients with a limited future liver remnant, portal vein embolization, combined ablation and resection, and associating liver partition and portal vein ligation for staged hepatectomy have been advocated, and each has their pros and cons. The role of neoadjuvant and adjuvant chemotherapy is still debated. Targeted biological agents and loco-regional therapies (thermal ablation, intra-arterial chemo- or radio-embolization, and stereotactic radiotherapy) further improve the already favourable results. The recent debate about offering liver transplantation to highly selected patients needs validation from large clinical trials. Evidence-based protocols are missing, and therefore optimal management of hepatic metastasis should be personalized and determined by a multi-disciplinary team.

Integrating Systemic Therapies into the Multimodality Treatment of Resectable Colorectal Liver Metastases

Colorectal carcinoma (CRC) is one of the most common cancers worldwide. A considerable proportion of CRC patients may present with metastatic disease either at upfront presentation (synchronous with the primary) or following diagnosis and treatment of the primary tumor (metachronous). Management of CRC liver metastases is a challenging endeavor which frequently necessitates proper assessment of patient- and disease-related factors. There is an opportunity within the management of CRC liver metastases to incorporate multiple treatment modalities (including surgery, other locoregional treatments, and systemic therapy). The current review aims to provide an updated overview on the optimal management strategy for CRC patients with liver metastases with a specific focus on the integration of systemic and/or locoregional treatments among patients with resectable or potentially resectable disease.

FOLFIRI plus panitumumab in the treatment of wild-type KRAS and wild-type NRAS metastatic colorectal cancer

Background

The aim of this study was to investigate the efficacy and safety of first-line panitumumab plus folinic acid, 5-fluorouracil and irinotecan (FOLFIRI) in patients with wild-type KRAS and wild-type NRAS metastatic colorectal cancer (mCRC).

Methods

Patients with wild-type KRAS and wild-type NRAS mCRC presenting to the medical oncology department of the Okmeydani Training and Research Hospital in Istanbul, Turkey, between April 2014 and January 2018 were enrolled in this study.

Results

A total of 64 patients (35 males and 29 females) with a median age of 59 (35–81) years old were enrolled. The median follow-up was 18.9 months, and the median progression-free survival was 13 months. The median overall survival (OS) was 26 months in the patients with wild-type KRAS and wild-type NRAS mCRC. It was 90.4% for the 6-month OS, 79.5% for the 1-year OS, 53.7% for the 2-year OS and 31.1% for the 3-year OS. The median OS of the patients who underwent metastasectomies was 40 [95% confidence interval (CI) = 19.9–60.1] months, and the median OS of the patients without metastasectomies was 22 (95% CI = 17.7–26.4) months. There was a statistically significant difference between these (P = 0.007).

Conclusion

The first-line FOLFIRI plus panitumumab was associated with favourable efficacy in the patients with wild-type KRAS and wild-type NRAS mCRC, and it was well tolerated. The removal of the metastases that became resectable after chemotherapy further prolonged the patients’ survival.

Trial registration

Retrospectively registered: 33886

Relevance of liver-limited disease in metastatic colorectal cancer: Subgroup findings of the FIRE-3/AIO KRK0306 trial

In metastatic colorectal cancer (mCRC), liver-limited disease (LLD) is associated with a higher chance of metastectomy leading to long-term survival. However, limited data describes the prognostic and predictive relevance of initially unresectable LLD with regard to targeted first-line therapy. The present analysis investigated the relevance of initially unresectable LLD in mCRC patients treated with targeted therapy against either the epidermal growth factor receptor (EGFR) or vascular epithelial growth factor (VEGF). The analysis was performed based on FIRE-3, a randomized phase III trial comparing first-line chemotherapy with FOLFIRI plus either cetuximab (anti-EGFR) or bevacizumab (anti-VEGF) in RAS wild-type (WT) mCRC. Of 400 patients, 133 (33.3%) had LLD and 267 (66.8%) had non-LLD. Median overall survival (OS) was significantly longer in LLD compared to non-LLD patients (36.0 vs. 25.4 months; hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.51-0.87; p = 0.002). In a multivariate analysis also including secondary hepatic resection as time-dependent variable, LLD status was independently prognostic for OS (HR = 0.67; 95% CI: 0.50-0.91; p = 0.01). As assessed by interaction tests, treatment benefit from FOLFIRI plus cetuximab compared to FOLFIRI plus bevacizumab was independent of LLD status with regard to objective response rate (ORR), early tumour shrinkage ≥20% (ETS), depth of response (DpR) and OS (all p > 0.05). In conclusion, LLD could be identified as a prognostic factor in RAS-WT mCRC, which was independent of hepatic resection in patients treated with targeted therapy. LLD had no predictive relevance since benefit from FOLFIRI plus cetuximab over bevacizumab was independent of LLD status.

Conversion to Resection in Patients Receiving Systemic Chemotherapy for Unresectable and/or Metastatic Colorectal Cancer-Predictive Factors and Prognosis

BACKGROUND

Systemic chemotherapy increases the possibility of resection in patients with initially unresectable colorectal cancer (CRC), especially patients with hepatic metastasis. However, the predictive factors and prognosis of conversion to resection after chemotherapy in patients with various organ metastases remain largely unknown.

PATIENTS AND METHODS

We reviewed the data from metastatic CRC (mCRC) patients who had received oxaliplatin- or irinotecan-based systemic chemotherapy from 2005 to 2016. The predictors for conversion to surgery were assessed by multivariate analyses. Cancer-free survival and overall survival after the initiation of treatment were compared between patients who had undergone successful conversion therapy and those who had undergone surgery first for resectable stage IV CRC.

RESULTS

Of 99 mCRC patients receiving first-line chemotherapy, 23 underwent secondary surgical resection. Single organ metastasis, the presence of liver metastases, and the use of biologic agents were independent predictors of successful conversion therapy. The long-term survival of patients who underwent successful secondary surgery did not differ significantly from that of the 112 patients with resectable stage IV CRC who had undergone surgery first.

CONCLUSION

Liver metastases and single organ metastasis were more likely to be resected after chemotherapy than were other metastatic lesions in mCRC. The use of biologic agents contributed to the increased conversion rate. Successful conversion resulted in outcomes similar to those of resectable stage IV CRC.

BRAF Mutations as Predictive Biomarker for Response to Anti-EGFR Monoclonal Antibodies

Recently, the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) recommended that patients with epidermal growth factor receptor (EGFR)-expressing metastatic colorectal cancer could be treated with anti-EGFR monoclonal antibodies (mAbs) cetuximab and panitumumab only in absence of Rat-Sarcoma (RAS) mutations. In addition to the previously established biomarker Kirsten rat sarcoma viral oncogene homolog (KRAS) exon 2, cumulative evidence also shows that patients whose tumors harbor KRAS exons 3 or 4 and neuroblastoma rat-sarcoma viral oncogene homolog (NRAS) exons 2, 3, and 4 mutations are found unlikely to benefit from anti-EGFR treatment.In line with the resistance of RAS mutated (mt) tumors, treatment response in BRAFmt tumors may also be altered given their important role in the EGFR signaling pathway. However, BRAF is not recommended as predictive biomarker yet because the evidence for the impact of BRAF mutations on treatment outcome is considered insufficient.This article summarizes the evidence for the impact of BRAF mutations on treatment outcome of anti-EGFR mAbs. Based on a review of literature, eight meta-analyses were included that consistently show that patients with BRAF mutations have a lack of treatment benefit of anti-EGFR mAbs. After discussing the quality and quantity of available evidence, we conclude that evidence is stronger than suggested by ESMO and ASCO. Additionally, we highlight that the quality of evidence for BRAF is even higher than for extended RAS as a biomarker. We therefore advise ESMO and ASCO to reconsider BRAF status as a predictive biomarker for response.

IMPLICATIONS FOR PRACTICE

In metastatic colorectal cancer (mCRC), therapy with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies cetuximab and panitumumab is indicated in absence of RAS mutations. Cumulative evidence shows that patients with BRAF mutations, who comprise 10% of the mCRC population, do not benefit from anti-EGFR-antibody treatment. Although guidelines state that evidence for BRAF as a predictive marker is insufficient, we highlight that the quality and quantity of evidence is higher than suggested. We therefore encourage the use of BRAF as a predictive marker in order to exclude patients from therapy for whom limited treatment benefit is expected.

First-line panitumumab plus FOLFOX4 or FOLFIRI in colorectal cancer with multiple or unresectable liver metastases: A randomised, phase II trial (PLANET-TTD)

BACKGROUND

In first-line wild-type (WT)-Kirsten rat sarcoma viral oncogene homologue (KRAS) metastatic colorectal cancer (mCRC), panitumumab (Pmab) improves outcomes when added to FOLFOX [folinic acid, 5-fluorouracil, and oxaliplatin] or FOLFIRI [folinic acid, 5-fluorouracil, and irinotecan]. However no trial has directly compared these combinations.

METHODS

Multicentre, open-label study in untreated patients ≥ 18 years with (WT)-KRAS mCRC and multiple or unresectable liver-limited disease (LLD) randomised to either Pmab-FOLFOX4 or Pmab-FOLFIRI. The primary end-point was objective response rate (ORR). Secondary end-points included liver metastases resection rate (R0 + R1), progression-free survival (PFS), overall survival (OS), adverse events and perioperative safety. Exploratory end-points were: response by RAS status, early tumour shrinkage (ETS) and depth of response (DpR) in WT-RAS patients.

RESULTS

Data on 77 patients were analysed (38 Pmab-FOLFOX4; 39 Pmab-FOLFIRI; WT-RAS: 27/26, respectively). ORR was 74% with Pmab-FOLFOX4 and 67% with Pmab-FOLFIRI (WT-RAS: 78%/73%). Out of the above, 45% and 59% underwent surgical resection, respectively (WT-RAS: 37%/69%). The R0-R1 resection rate was 34%/46% (WT-RAS:26%/54%). Median PFS was 13/14 months (hazard ratio [HR] Pmab-FOLFIRI versus Pmab-FOLFOX4: 0.9; 95% confidence interval: [0.6-1.5]; WT-RAS:13/15; HR: 0.7 [0.4-1.3]). Median OS was 37/41 months (HR:1.0 [0.6-1.8]; WT-RAS: 39/49; HR:0.9 [0.4-1.9]). In WT-RAS patients with confirmed response, median DpR was 71%/66%, and 65%/77% of patients showed ETS ≥ 30%/ ≥ 20% at week 8, without significant differences between arms; these patients had longer median PFS and OS and higher resectability rates. Surgery was associated with longer survival. Perioperative and overall safety were similar, except for higher grade 3/4 neutropenia (40%/10%; p = 0.003) and neuropathy (13%/0%; p = 0.025) in the Pmab-FOLFOX4 arm.

CONCLUSIONS

In patients with WT-KRAS mCRC and LLD, both first-line Pmab-FOLFOX4 and Pmab-FOLFIRI resulted in high ORR and ETS, allowing potentially curative resection. No significant differences in efficacy were observed between the two regimens. (clinicaltrials.gov:NCT00885885).

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology

OBJECTIVES

- To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens.

METHODS

- The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted.

RESULTS

- Twenty-one guideline statements were established.

CONCLUSIONS

- Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented.

Molecular Biomarkers for the Evaluation of Colorectal Cancer

Objectives: To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens. Methods: The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted. Results: Twenty-one guideline statements were established. Conclusions: Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented.

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology

OBJECTIVES

To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens.

METHODS

The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted.

RESULTS

Twenty-one guideline statements were established.

CONCLUSIONS

Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented. Key Words: Molecular diagnostics; Gastrointestinal; Histology; Genetics; Oncology.

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and the American Society of Clinical Oncology

Purpose Molecular testing of colorectal cancers (CRCs) to improve patient care and outcomes of targeted and conventional therapies has been the center of many recent studies, including clinical trials. Evidence-based recommendations for the molecular testing of CRC tissues to guide epidermal growth factor receptor (EGFR) -targeted therapies and conventional chemotherapy regimens are warranted in clinical practice. The purpose of this guideline is to develop evidence-based recommendations to help establish standard molecular biomarker testing for CRC through a systematic review of the literature. Methods The American Society for Clinical Pathology (ASCP), College of American Pathologists (CAP), Association for Molecular Pathology (AMP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to develop an evidence-based guideline to help establish standard molecular biomarker testing, guide targeted therapies, and advance personalized care for patients with CRC. A comprehensive literature search that included over 4,000 articles was conducted to gather data to inform this guideline. Results Twenty-one guideline statements (eight recommendations, 10 expert consensus opinions and three no recommendations) were established. Recommendations Evidence supports mutational testing for genes in the EGFR signaling pathway, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize molecular testing for predictive and prognostic molecular biomarkers involve selection of assays, type of specimens to be tested, timing of ordering of tests and turnaround time for testing results. Additional information is available at: www.asco.org/CRC-markers-guideline and www.asco.org/guidelineswiki.

Chemotherapy Plus Cetuximab versus Chemotherapy Alone for Patients with KRAS Wild Type Unresectable Liver-Confined Metastases Colorectal Cancer: An Updated Meta-Analysis of RCTs

Purpose. Our study analyses clinical trials and evaluates the efficacy of adding cetuximab in systematic chemotherapy for unresectable colorectal cancer liver-confined metastases patients. Materials and Methods. Search EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials for RCTs comparing chemotherapy plus cetuximab with chemotherapy alone for KRAS wild type patients with colorectal cancer liver metastases (CRLMs). We calculated the relative risks (RRs) with 95% confidence interval and performed meta-analysis of hazard ratios (HRs) for the R0 resection rate, the overall response rate (ORR), the progression-free survival (PFS) and overall survival (OS). Results. 1173 articles were retrieved and 4 RCTs were available for our study. The four studies involved 504 KRAS wild type patients with CRLMs. The addition of cetuximab significantly improved all the 4 outcomes: the R0 resection rate (RR 2.03, p = 0.004), the ORR (RR 1.76, p < 0.00001), PFS (HR 0.63, p < 0.0001), and also OS (HR 0.74, p = 0.04); the last outcome is quite different from the conclusion published before. Conclusions. Although the number of patients analysed was limited, we found that the addition of cetuximab significantly improves the outcomes in KRAS wild type patients with unresectable colorectal cancer liver-confined metastases. Cetuximab combined with systematic chemotherapy perhaps suggests a promising choice for KRAS wild type patients with unresectable liver metastases.

How close are we to standardised extended RAS gene mutation testing? The UK NEQAS evaluation

AIMS

Since 2008, KRAS mutation status in exon 2 has been used to predict response to anti-EGFR therapies. Recent evidence has demonstrated that NRAS status is also predictive of response. Several retrospective 'extended RAS' analyses have been performed on clinical trial material. Despite this, are we really moving towards such extended screening practice in reality?

METHODS

Data were analysed from four consecutive UK National External Quality Assessment Service for Molecular Genetics Colorectal cancer External Quality Assessment schemes (during the period 2014-2016), with up to 110 laboratories (worldwide) participating in each scheme. Testing of four or five tumour samples is required per scheme. Laboratories provided information on which codons were routinely screened, and provided genotyping and interpretation results for each sample.

RESULTS

At least 85% of laboratories routinely tested KRAS codons 12, 13 and 61. Over the four schemes, an increasing number of laboratories routinely tested KRAS codons 59, 117 and 146. Furthermore, more laboratories were introducing next generation sequencing technologies. The pattern of 'extended testing' was reassuringly similar for NRAS, although fewer laboratories currently test for mutations in this gene. Alarmingly, still only 36.1% and 24.1% of participating laboratories met the ACP Molecular Pathology and Diagnostics Group and American Society of Clinical Oncology guidelines, respectively, for extended RAS testing in the latest assessment.

CONCLUSIONS

Despite recommendations in the UK and USA on extended RAS testing, there has clearly been, based on these results, a delay in implementation. Inadequate testing results in patients being subjected to harmful treatment regimens, which would not be the case, were routine practice altered, in line with evidence-based guidelines.

Advances of Targeted Therapy in Treatment of Unresectable Metastatic Colorectal Cancer

Despite being one of the most frequently diagnosed cancers worldwide, prognosis of metastatic colorectal cancer (CRC) was poor. Development and introduction of biologic agents in treatment of patients with metastatic CRC have brought improved outcomes. Monoclonal antibodies directing epidermal growth factor receptors and vascular endothelial growth factor are main biologic agents currently used in treatment of metastatic CRC. Encouraged by results from many clinical trials demonstrating efficacy of those monoclonal antibodies, the combination therapy with those targeted agents and conventional chemotherapeutic agents has been established as the standard therapy for patients with metastatic CRC. However, emergency of resistance to those target agents has limited the efficacy of treatment, and strategies to overcome the resistance are now being investigated by newly developed biological techniques clarifying how to acquire resistance. Here, we introduce mechanisms of action of the biologic agents currently used for treatment of metastatic CRC and several landmark historical clinical studies which have changed the main stream of treatment. The mechanism of resistance to those agents, one of serious problems in treatment metastatic CRC, and ongoing clinical trials to overcome the limitations and improve treatment outcomes will also be presented in this review.

Current treatment options for patients with initially unresectable isolated colorectal liver metastases

The development of liver metastases is a common clinical entity in the clinical course of colorectal cancer. For patients with isolated liver involvement, surgical resection is the only treatment that can provide a chance of prolonged survival and cure. However, most of these patients are not initially eligible for the surgery. Selected patients with initially considered to have unresectable disease may become resectable after systemic (chemotherapy ± biological therapy) and loco-regional treatment modalities including hepatic arterial infusion. Patients who have colorectal liver metastases ideally should be referred to a multidisciplinary cancer care team in order to identify the most optimal management approach.

Extended RAS Gene Mutation Testing in Metastatic Colorectal Carcinoma to Predict Response to Anti-Epidermal Growth Factor Receptor Monoclonal Antibody Therapy: American Society of Clinical Oncology Provisional Clinical Opinion Update 2015

PURPOSE

An American Society of Clinical Oncology Provisional Clinical Opinion (PCO) offers timely clinical direction after publication or presentation of potentially practice-changing data from major studies. This PCO update addresses the utility of extended RAS gene mutation testing in patients with metastatic colorectal cancer (mCRC) to detect resistance to anti-epidermal growth factor receptor (EGFR) monoclonal antibody (MoAb) therapy.

CLINICAL CONTEXT

Recent results from phase II and III clinical trials in mCRC demonstrate that patients whose tumors harbor RAS mutations in exons 2 (codons 12 and 13), 3 (codons 59 and 61), and 4 (codons 117 and 146) are unlikely to benefit from therapy with MoAbs directed against EGFR, when used as monotherapy or combined with chemotherapy.

RECENT DATA

In addition to the evidence reviewed in the original PCO, 11 systematic reviews with meta-analyses, two retrospective analyses, and two health technology assessments based on a systematic review were obtained. These evaluated the outcomes for patients with mCRC with no mutation detected or presence of mutation in additional exons in KRAS and NRAS. PCO: All patients with mCRC who are candidates for anti-EGFR antibody therapy should have their tumor tested in a Clinical Laboratory Improvement Amendments-certified laboratory for mutations in both KRAS and NRAS exons 2 (codons 12 and 13), 3 (codons 59 and 61), and 4 (codons 117 and 146). The weight of current evidence indicates that anti-EGFR MoAb therapy should only be considered for treatment of patients whose tumor is determined to not have mutations detected after such extended RAS testing.

Is more not better?: combination therapies in colorectal cancer treatment

The treatment of colorectal cancer has evolved dramatically in recent years with the availability of new chemotherapeutic agents and inhibitors of the vascular endothelial growth factor- and epidermal growth factor-signaling pathways. The incremental benefit of each individual line of therapy for advanced disease is relatively small. Advances in our ability to select patients should improve the cost-effectiveness of our treatment strategies (avoiding unnecessary toxicity in the patients who are unlikely to benefit and accepting the potential for adverse events in the patients who stand to benefit the most from a given regimen).

Incorporating anti-VEGF pathway therapy as a continuum of care in metastatic colorectal cancer

Metastatic cancer was previously treated with distinctive lines of chemotherapy regimens upon disease progression or toxicity, yet the choices of therapy are actually interrelated, with the selection of a first-line regimen in part determining the choices available for subsequent treatment. Lately the therapeutic approach based on separate lines of treatment, tends to be replaced from a perspective strategical approach, that of the "continuum of care". This strategy targets to an improved overall survival, improved of quality of life and minimization of toxicity through upfront design of treatment selection and sequencing, exposure to all available drugs and minimization of unnecessary treatment. Anti-VEGF treatment has a well-documented role in this approach. Bevacizumab should be included in upfront treatment regimens for all mCRC patients independently of RAS status, unless contraindicated. Upfront bevacizumab could be combined with all available regimens since the optimal choice of backbone chemotherapy is yet to be defined. In RAS wild-type population, when metastasectomy is the target, an anti-EGFR combination is also a valid approach. Maintenance with bevacizumab and fluoropyrimidines should be considered upon intolerance of induction treatment and/or disease stabilization; maintenance with bevacizumab monotherapy should be avoided. In highly selected patients, complete treatment cessation could be also an option. Continuation with bevacizumab upon first progression and switch of the "backbone" chemotherapy is a validated approach. Patients progressing after first-line oxaliplatin regimen including bevacizumab combinations could be treated with an aflibercept-irinotecan combination. When no more options are available, regorafenib monotherapy should be the following choice. Combinations of anti-VEGF and anti-EGFR treatment have no place in this approach and are not indicated.

KRAS mutation testing of tumours in adults with metastatic colorectal cancer: a systematic review and cost-effectiveness analysis

BACKGROUND

Bowel cancer is the third most common cancer in the UK. Most bowel cancers are initially treated with surgery, but around 17% spread to the liver. When this happens, sometimes the liver tumour can be treated surgically, or chemotherapy may be used to shrink the tumour to make surgery possible. Kirsten rat sarcoma viral oncogene (KRAS) mutations make some tumours less responsive to treatment with biological therapies such as cetuximab. There are a variety of tests available to detect these mutations. These vary in the specific mutations that they detect, the amount of mutation they detect, the amount of tumour cells needed, the time to give a result, the error rate and cost.

OBJECTIVES

To compare the performance and cost-effectiveness of KRAS mutation tests in differentiating adults with metastatic colorectal cancer whose metastases are confined to the liver and are unresectable and who may benefit from first-line treatment with cetuximab in combination with standard chemotherapy from those who should receive standard chemotherapy alone.

DATA SOURCES

Thirteen databases, including MEDLINE and EMBASE, research registers and conference proceedings were searched to January 2013. Additional data were obtained from an online survey of laboratories participating in the UK National External Quality Assurance Scheme pilot for KRAS mutation testing.

METHODS

A systematic review of the evidence was carried out using standard methods. Randomised controlled trials were assessed for quality using the Cochrane risk of bias tool. Diagnostic accuracy studies were assessed using the QUADAS-2 tool. There were insufficient data for meta-analysis. For accuracy studies we calculated sensitivity and specificity together with 95% confidence intervals (CIs). Survival data were summarised as hazard ratios and tumour response data were summarised as relative risks, with 95% CIs. The health economic analysis considered the long-term costs and quality-adjusted life-years associated with different tests followed by treatment with standard chemotherapy or cetuximab plus standard chemotherapy. The analysis took a 'no comparator' approach, which implies that the cost-effectiveness of each strategy will be presented only compared with the next most cost-effective strategy. The de novo model consisted of a decision tree and Markov model.

RESULTS

The online survey indicated no differences between tests in batch size, turnaround time, number of failed samples or cost. The literature searches identified 7903 references, of which seven publications of five studies were included in the review. Two studies provided data on the accuracy of KRAS mutation testing for predicting response to treatment in patients treated with cetuximab plus standard chemotherapy. Four RCTs provided data on the clinical effectiveness of cetuximab plus standard chemotherapy compared with that of standard chemotherapy in patients with KRAS wild-type tumours. There were no clear differences in the treatment effects reported by different studies, regardless of which KRAS mutation test was used to select patients. In the 'linked evidence' analysis the Therascreen KRAS RGQ PCR Kit (QIAGEN) was more expensive but also more effective than pyrosequencing or direct sequencing, with an incremental cost-effectiveness ratio of £17,019 per quality-adjusted life-year gained. In the 'assumption of equal prognostic value' analysis the total costs associated with the various testing strategies were similar.

LIMITATIONS

The results assume that the differences in outcomes between the trials were solely the result of the different mutation tests used to distinguish between patients; this assumption ignores other factors that might explain this variation.

CONCLUSIONS

There was no strong evidence that any one KRAS mutation test was more effective or cost-effective than any other test.

STUDY REGISTRATION

PROSPERO CRD42013003663.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Pathological response after neoadjuvant bevacizumab- or cetuximab-based chemotherapy in resected colorectal cancer liver metastases

Neoadjuvant chemotherapy (NACT) prior to liver resection is advantageous for patients with colorectal cancer liver metastases (CLM). Bevacizumab- or cetuximab-based NACT may affect patient outcome and curative resection rate, but comparative studies on differential tumour regression grade (TRG) associated with distinct antibodies-associated regimens are lacking. Ninety-three consecutive patients received NACT plus bevacizumab (n = 46) or cetuximab (n = 47) followed by CLM resection. Pathological response was determined in each resected metastasis as TRG rated from 1 (complete) to 5 (no response). Except for KRAS mutations prevailing in bevacizumab versus cetuximab (57 vs. 21 %, p = 0.001), patients characteristics were well balanced. Median follow-up was 31 months (IQR 17-48). Bevacizumab induced significantly better pathological response rates (TRG1-3: 78 vs. 34 %, p < 0.001) as well as complete responses (TRG1: 13 vs. 0 %, p = 0.012) with respect to cetuximab. Three-year progression-free survival (PFS) and overall survival (OS) were not significantly different in the two cohorts. At multivariable analysis, significant association with pathological response was found for number of resected metastases (p = 0.015) and bevacizumab allocation (p < 0.001), while KRAS mutation showed only a trend. Significant association with poorer PFS and OS was found for low grades of pathological response (p = 0.009 and p < 0.001, respectively), R2 resection or presence of extrahepatic disease (both p < 0.001) and presence of KRAS mutation (p = 0.007 and p < 0.001, respectively). Bevacizumab-based regimens, although influenced by the number of metastases and KRAS status, improve significantly pathological response if compared to cetuximab-based NACT. Possible differential impact among regimens on patient outcome has still to be elucidated.

Efficacy of oxaliplatin-based chemotherapy + bevacizumab as first-line treatment for advanced colorectal cancer: a systematic review and pooled analysis of published trials

OBJECTIVES

Oxaliplatin and either capecitabine or infusional/bolus 5-fluorouracil (5FU)-based chemotherapy + bevacizumab (XELOX + B and FOLFOX + B) represent 2 of the approved first-line treatments for advanced colorectal cancer (CRC). However, the addition of B did not offer a survival benefit compared with FOLFOX/XELOX alone in the phase III, NO16966 trial. The aim of this review was to aggregate all published data on the efficacy of XELOX and FOLFOX-B in prospective and retrospective studies as first-line therapy for stage IV CRC.

METHODS

We performed a systematic review, through PubMed and EMBASE, of all published studies exploring the efficacy of fluoropyrimidines + oxaliplatin + B-based chemotherapy as first-line chemotherapy in advanced CRC patients. Pooled estimates of the response rates, weighted medians of progression-free survival, and overall survival from all FOLFOX + B and XELOX + B arms were calculated.

RESULTS

A total of 25 studies were retrieved, with a total of 7878 patients. Overall, the pooled response rates (n=20 publications) was 49.1%. The median progression-free survival and overall survival (n=21 and 22 publications, respectively) were 10.3 and 23.7 months, respectively. The pooled median rate of surgical resection of metastases (n=13 publications) was 14%.

CONCLUSIONS

XELOX + B and FOLFOX + B are active combinations as first-line treatment of advanced CRC. The efficacy is confirmed for the first time from this pooled analysis of 25 trials. Both the XELOX + B and the FOLFOX + B arms represent 2 of the cornerstone combinations when B is used as first-line therapy.

Chemotherapy and targeted therapy for patients with initially unresectable colorectal liver metastases, focusing on conversion hepatectomy and long-term survival

BACKGROUND

Eight years have passed since the introduction of chemotherapy (chemo) and targeted therapy regimens for colorectal liver metastases (CRLM). This study aimed to clarify the effectiveness of chemo and targeted therapy in facilitating conversion hepatectomy and improving long-term survival in Japanese patients with CRLM.

METHODS

A total of 199 patients with CRLM were treated between May 2005 and August 2012. Initial therapies for these patients included straightforward hepatic resection (n = 48; 24 %), induction chemotherapy (n = 148; 74 %), and radiofrequency ablation (n = 3; 2 %).

RESULTS

In 56 of 137 patients (40.1 %) with initially unresectable CRLM, 7.5 courses of chemo and targeted therapy downsized and converted tumors to resectable tumors. The 5-year cumulative overall survival (OS) rate and the median survival time were significantly higher for the resectable CRLM than for the unresectable CRLM (54.6 vs. 5.3 % and 77.3 vs. 21.3 months, respectively; P < .0001). Multivariate analysis revealed that conversion hepatectomy (hazard ratio [HR] 0.19; P < .001) and responder to chemo and targeted therapy (HR 0.46; P < .01) were independent prognostic factors for OS. Multivariate analysis also revealed that left-sided colon or rectal cancer (odds ratio [OR] 8.4; P < .05), H1/H2 metastases (OR 7.3; P < .05), no extrahepatic metastases (OR 52.6; P < .001), and responder to chemo and targeted therapy (OR 6.1; P < .05) were significant predictors of conversion hepatectomy.

CONCLUSIONS

A chemo and targeted therapy can facilitate conversion hepatectomy and allow for an excellent prognosis in patients with initially unresectable CRLM.

KRAS early testing: consensus initiative and cost-effectiveness evaluation for metastatic colorectal patients in an Italian setting

KRAS testing is relevant for the choice of the most appropriate first-line therapy of metastatic colorectal cancer (CRC). Strategies for preventing unequal access to the test should be implemented, but their relevance in the practice is related to economic sustainability. The study adopted the Delphi technique to reach a consensus on several topics. Issues related to execution of KRAS testing were identified by an expert’s board and proposed to 108 Italian oncologists and pathologists through two subsequent questionnaires. The emerging proposal was evaluated by decision analyses models employed by technology assessment agencies in order to assess cost-effectiveness. Alternative therapeutic strategies included most commonly used chemotherapy regimens alone or in combination with cetuximab or bevacizumab. The survey indicated that time interval for obtaining KRAS test should not exceed 15 days, 10 days being an optimal interval. To assure the access to proper treatment, a useful strategy should be to anticipate the test after radical resection in patients at high risk of relapse. Early KRAS testing in high risk CRC patients generates incremental cost-effectiveness ratios between 6,000 and 13,000 Euro per quality adjusted life year (QALY) gained. In extensive sensitivity analyses ICER’s were always below 15,000 Euro per QALY gained, far within the threshold of 60,000 Euro/QALY gained accepted by regulatory institutions in Italy. In metastatic CRC a time interval higher than 15 days for result of KRAS testing limits access to therapeutic choices. Anticipating KRAS testing before the onset of metastatic disease in patients at high risk does not affect the sustainability and cost-effectiveness profile of cetuximab in first-line mCRC. Early KRAS testing may prevent this inequality in high-risk patients, whether they develop metastases, and is a cost-effective strategy. Based on these results, present joined recommendations of Italian societies of Oncology and Pathology should be updated including early KRAS testing.

[Neoadjuvant chemotherapy or primary surgery for colorectal liver metastases. Pro primary surgery]

Approximately 50 % of patients with colorectal cancer (CRC) develop liver metastases, with the liver being the only site of metastasis in the majority of patients. Liver resection is the standard treatment of CRC liver metastases as it achieves a 5-year survival of 36-51 %. The primary goal in the treatment of non-resectable liver metastases is to achieve resectability by preoperative chemotherapy as even secondary liver resection after down-sizing is associated with improved overall survival. Furthermore, resectability can be increased by two-stage surgical procedures; however, the assessment of resectability varies widely even among experts in the field. In cases of suspected non-resectability patients should therefore be liberally admitted for a second opinion to centers of liver surgery. Perioperative chemotherapy in primarily resectable cases has only demonstrated an improvement in recurrence-free survival in subgroup analyses. Moreover, modern potent chemotherapy regimens increase the surgical morbidity depending on the duration of treatment: the lower the histological response of the metastases and the more treatment cycles are applied, the higher is the parenchymal damage with related surgical morbidity. Therefore, perioperative chemotherapy of resectable liver metastases should be viewed with caution and should not be considered the standard of care.

Factors influencing choice of chemotherapy in metastatic colorectal cancer (mCRC)

Management of metastatic colorectal cancer requires a multimodal approach and must be performed by an experienced, multidisciplinary expert team. The optimal choice of the individual treatment modality, according to disease localization and extent, tumor biology, and patient clinical characteristics, will be one that can maintain quality of life and long-term survival, and even cure selected patients. This review is an overview of the different therapeutic approaches available in metastatic colorectal cancer, for the purpose of defining personalized therapeutic algorithms according to tumor biology and patient clinical features.

Evaluation of prognostic factors in liver-limited metastatic colorectal cancer: a preplanned analysis of the FIRE-1 trial

Background:

Liver-limited disease (LLD) denotes a specific subgroup of metastatic colorectal cancer (mCRC) patients.

Patients and Methods:

A total of 479 patients with unresectable mCRC from an irinotecan-based randomised phase III trial were evaluated. Patients with LLD and non-LLD and hepatic resection were differentiated. Based on baseline patient characteristic, prognostic factors for hepatic resection were evaluated. Furthermore, prognostic factors for median overall survival (OS) were estimated via Cox regression in LLD patients.

Results:

Secondary liver resection was performed in 38 out of 479 patients (resection rate: 7.9%). Prognostic factors for hepatic resection were LLD, lactate dehydrogenase (LDH), node-negative primary, alkaline phosphatase (AP) and Karnofsky performance status (PS). Median OS was significantly increased after hepatic resection (48 months), whereas OS in LLD (17 months) and non-LLD (19 months) was comparable in non-resected patients. With the inapplicability of Koehne's risk classification in LLD patients, a new score based on only the independent prognostic factors LDH and white blood cell (WBC) provided markedly improved information on the outcome.

Conclusion:

Patients undergoing hepatic resection showed favourable long-term survival, whereas non-resected LLD patients and non-LLD patients did not differ with regard to progression-free survival and OS. The LDH levels and WBC count were confirmed as prognostic factors and provide a useful and simple score for OS-related risk stratification also in LLD.

FOLFIRI-bevacizumab as first-line chemotherapy in 3500 patients with advanced colorectal cancer: a pooled analysis of 29 published trials

Irinotecan and infusional bolus 5-fluorouracil (5-FU)-based chemotherapy (FOLFIRI [5-fluorouracil, folinic acid, irinotecan]) + bevacizumab (FOLFIRI-B) is 1 of the cornerstones of first-line treatment of advanced colorectal cancer (CRC). However, bevacizumab was approved for use after the AVF2107 trial that included a bolus 5-FU schedule (IFL [irinotecan + 5-FU + leucovorin]). No randomized trials have been published comparing FOLFIRI and FOLFIRI-B. The aim of this review is to pool all published data on the activity and efficacy of FOLFIRI-B as first-line therapy in treating advanced CRC in prospective and retrospective studies. We performed a systematic review, through PubMed and EMBASE, of all prospective and retrospective published studies exploring the efficacy of FOLFIRI-B as first-line chemotherapy in patients with advanced CRC. Pooled estimates of the response rate (RR) and weighted median of progression-free survival (PFS) and overall survival (OS) from all FOLFIRI-B-related studies were calculated. Rates of metastasectomy and bevacizumab-related severe toxicities were reported. A total of 29 studies (8 randomized controlled trials, 1 phase IV trial, 2 phase II trials, 4 observational studies, 4 prospective nonrandomized cohort studies, and 10 retrospective case series) were retrieved for a total of 3502 patients. Overall, the pooled RR (n = 22 publications) was 51.4%. Median PFS and OS (n = 25 and 20 publications) were 10.8 months (95% confidence interval [CI], 8.9-12.8) and 23.7 months (95% CI, 18.1-31.6), respectively. The pooled rate of surgical resection of metastases (any site of surgery: n = 7 publications) was 9.3% (range, 3.6%-24%), and rate of liver resections (liver surgery only: n = 7 publications) was 18% (range 8%-25%). Grade 3-4 bevacizumab-related toxicities were also comparable with larger phase III trials. FOLFIRI-B is used worldwide as upfront treatment for stage IV CRC. This indication is confirmed by robust data about RR, PFS, and survival obtained, which this pooled analysis of 29 trials also found. FOLFIRI-B remains 1 of the referent combinations when bevacizumab is considered as first-line therapy.

Randomized controlled trial of cetuximab plus chemotherapy for patients with KRAS wild-type unresectable colorectal liver-limited metastases

PURPOSE

To assess the effects of cetuximab plus chemotherapy as first-line treatment for unresectable colorectal liver metastases (CLMs).

PATIENTS AND METHODS

After resection of their primary tumors, patients with KRAS wild-type synchronous nonresectable liver-limited metastases from colorectal cancer were randomly assigned to receive chemotherapy (FOLFIRI [fluorouracil, leucovorin, and irinotecan] or mFOLFOX6 [modified fluorouracil, leucovorin, and oxaliplatin]) plus cetuximab (arm A) or chemotherapy alone (arm B). The primary end point was the rate of patients converted to resection for liver metastases. Secondary end points included tumor response and survival.

RESULTS

The intent-to-treat population comprised 138 patients; 70 patients were randomly assigned to arm A and 68 to arm B. After a median of 25.0 months of follow-up, the 3-year overall survival (OS) rate and median survival time (MST) for all patients were 30% and 24.4 months, respectively. The R0 resection rates for liver metastases were 25.7% (18 of 70 patients) in arm A and 7.4% (five of 68 patients) in arm B, which were significantly different (P < .01). Patients in arm A had improved objective response rates (57.1% v 29.4%; P < .01), increased 3-year OS rate (41% v 18%; P = .013) and prolonged MST (30.9 v 21.0 months; P = .013) compared with those in arm B. In addition, in arm A, patients who had resection of liver metastases had a significantly improved MST (46.4 v 25.7 months; P < .01) compared with those who did not undergo surgery.

CONCLUSION

For patients with initially unresectable KRAS wild-type CLMs, cetuximab combined with chemotherapy improved the resectability of liver metastases and improved response rates and survival compared with chemotherapy alone.