Should the results of the new EPOC trial change practice in the management of patients with resectable metastatic colorectal cancer confined to the liver?

LM02 trial Perioperative treatment with panitumumab and FOLFIRI in patients with wild-type RAS, potentially resectable colorectal cancer liver metastases-a phase II study

Background

Twenty percent of colorectal cancer liver metastases (CLMs) are initially resectable with a 5-year survival rate of 25%-40%. Perioperative folinic acid, 5-fluorouracil, oxaliplatin (FOLFOX) increases progression-free survival (PFS). In advanced disease, the addition of targeting therapies results in an overall survival (OS) advantage. The aim of this study was to evaluate panitumumab and FOLFIRI as perioperative therapy in resectable CLM.

Methods

Patients with previously untreated, wild-type Rat sarcoma virus (RAS), and resectable CLM were included. Preoperative four and postoperative eight cycles of panitumumab and folinic acid, 5-fluorouracil, irinotecan (FOLFIRI) were administered. Primary objectives were efficacy and safety. Secondary endpoints included PFS and OS.

Results

We enrolled 36 patients in seven centers in Austria (intention-to-treat analyses, 35 patients). There were 28 men and seven women, and the median age was 66 years. About 91.4% completed preoperative therapy and 82.9% underwent liver resection. The R0 resection rate was 82.7%. Twenty patients started and 12 patients completed postoperative chemotherapy. The objective radiological response rate after preoperative therapy was 65.7%. About 20% and 5.7% of patients had stable disease and progressive disease, respectively. The most common grade 3 adverse events were diarrhea, rash, and leukopenia during preoperative therapy. One patient died because of sepsis, and one had a pulmonary embolism grade 4. After surgery, two patients died because of hepatic failure. Most common grade 3 adverse events during postoperative therapy were skin toxicities/rash and leukopenia/neutropenia, and the two grade 4 adverse events were stroke and intestinal obstruction. Median PFS was 13.2 months. The OS rate at 12 and 24 months were 85.6% and 73.3%, respectively.

Conclusions

Panitumumab and FOLFIRI as perioperative therapy for resectable CLM result in a radiological objective response rate in 65.7% of patients with a manageable grade 3 diarrhea rate of 14.3%. Median PFS was 13.2 months, and the 24-month OS rate was 73.3%. These data are insufficient to widen the indication of panitumumab from the unresectable setting to the setting of resectable CLM.

Perioperative Systemic Chemotherapy for Colorectal Liver Metastasis: Recent Updates

Simple Summary

The development of cytotoxic chemotherapy, targeted agents and immune check point inhibitors has improved survival outcomes and quality of life in patients diagnosed with metastatic colorectal cancer (CRC). Long-term survival and cure are possible in well-selected CRC patients with liver metastases (LM). The criteria for resectable LM and the eligibility of patients should be evaluated at the time of diagnosis or during the clinical course via a multidisciplinary team approach. The advantages of adjuvant chemotherapy after curative resection of LM are uncertain currently. Systemic preoperative chemotherapy may convert unresectable LM to a resectable type. However, the optimal combination of systemic drugs and treatment strategy has yet to be established. This article summarizes recent reports of perioperative systemic treatment for patients with colorectal liver metastases (CLM). This review provides an update for physicians involved in managing patients with CLM.

Abstract

The liver is the most common site of metastases for colorectal cancer. Complete resection in some patients with resectable liver metastases (LM) can lead to long-term survival and cure. Adjuvant systemic chemotherapy after complete resection of LM improves recurrence-free survival; however, the overall survival benefit is not clear. In selected patients, preoperative systemic treatment for metastatic colorectal cancer can convert unresectable to resectable cancer. This review will focus on patient selection, and integration of perioperative and postoperative systemic treatment to surgery in resectable and initially unresectable LM. Additionally, new drugs and biomarkers will be discussed.

Statistical aspects in adjuvant and neoadjuvant trials for gastrointestinal cancer in 2020: focus on time-to-event endpoints

PURPOSE OF REVIEW

Clinical-trial design, analysis, and interpretation entails the use of efficient and reliable endpoints. Statistical issues related to endpoints warrant continued attention, as they may have a substantial impact on the conduct of clinical trials and on interpretation of their results.

RECENT FINDINGS

We review concepts and discuss recent developments related to the use of time-to-event endpoints in studies on adjuvant and neoadjuvant therapy for colon, pancreatic, and gastric adenocarcinomas. The definition of endpoints has varied to a considerable extent in these settings. Although these variations are relevant in interpreting results from individual trials, they probably have a small impact when considered in aggregate. In terms of surrogacy, most published reports so far have used aggregated data. A few studies based on the preferred method of a metaanalysis of individual-patient data have shown that disease-free survival (DFS) is a surrogate for overall survival in the adjuvant therapy of stage III colon cancer and in gastric cancer, whereas DFS with a landmark of six months is a surrogate for overall survival in the neoadjuvant therapy of adenocarcinoma of the esophagus, gastroesophageal junction, or stomach.

SUMMARY

Testing novel agents in gastrointestinal cancer requires continued attention to statistical issues related to endpoints.

Statistical Considerations for Trials in Adjuvant Treatment of Colorectal Cancer

The design of the best possible clinical trials of adjuvant interventions in colorectal cancer will entail the use of both time-tested and novel methods that allow efficient, reliable and patient-relevant therapeutic development. The ultimate goal of this endeavor is to safely and expeditiously bring to clinical practice novel interventions that impact patient lives. In this paper, we discuss statistical aspects and provide suggestions to optimize trial design, data collection, study implementation, and the use of predictive biomarkers and endpoints in phase 3 trials of systemic adjuvant therapy. We also discuss the issues of collaboration and patient centricity, expecting that several novel agents with activity in the (neo)adjuvant therapy of colon and rectal cancers will become available in the near future.

A Multicenter Phase 2 Trial to Evaluate the Efficacy of mFOLFOX6 + Cetuximab as Induction Chemotherapy to Achieve R0 Surgical Resection for Advanced Colorectal Liver Metastases (NEXTO Trial)

BACKGROUND

The effect of cetuximab plus mFOLFOX on downsizing of the tumors for curative resection has yet to be assessed for patients with advanced colorectal liver metastases (CRLMs). This study aimed to assess the oncologic benefit of cetuximab plus mFOLFOX for wild-type KRAS patients with advanced CRLMs.

METHODS

In this multicenter phase 2 trial, patients with technically unresectable tumor and/or five or more CRLMs harboring wild-type KRAS were treated with mFOLFOX plus cetuximab. The patients were assessed for resectability after 4 treatments, and then every 2 months up to 12 treatments. Patients with resectable disease were offered surgery after a waiting period of 1 month. The primary end point of the study was the R0 resection rate. The secondary end points were safety, progression-free survival (PFS), and overall survival (OS). The study is registered with the University Hospital Medical Information Network-Clinical Trials Registry Clinical Trials Registry (no. C000007923).

RESULTS

Between 2012 and 2015, 50 patients from 13 centers were enrolled in this trial. Two patients were excluded because they had not received induction therapy. The 48 patients had a complete response rate of 0% and a partial response rate of 64.6%. For 26 R0 resections (54.2%) and 5 R1 resections (10.4%), no mortality occurred. During a median follow-up period of 31 months, the median OS for all the patients was calculated to be 41 months (95% confidence interval, 28-not reached). The 3-year OS rate was 59%.

CONCLUSION

For patients with advanced CRLMs harboring wild-type KRAS, cetuximab administered in combination with mFOLFOX yields high response rates, leading to significantly high R0 resection rates and favorable prognoses.

Emerging Systemic Therapies for Colorectal Cancer

Despite advances over the past 20 years in colorectal cancer (CRC) screening, diagnosis, and treatment, survival outcomes remain suboptimal. Five-year survival for patients with locally advanced CRC is 69%; 5-year survival drops to 12% for patients with metastatic disease. Novel, effective systemic therapies are needed to improve long-term outcomes. In this review, we describe currently available systemic therapies for the treatment of locally advanced and metastatic CRC and discuss emerging therapies, including encouraging advances in identifying novel targeted agents and exciting responses to immunotherapeutic agents.

Phase II Study of Preoperative Capecitabine and Oxaliplatin-based Intensified Chemoradiotherapy With or Without Induction Chemotherapy in Patients With Locally Advanced Rectal Cancer and Synchronous Liver-limited Resectable Metastases

Supplemental Digital Content is available in the text.

Objectives:

Controversy surrounds the management of patients with locally advanced rectal cancer with synchronous resectable liver metastases (LMs). This study was designed to improve both systemic and local control in these patients.

Methods:

Patients with locally advanced rectal cancer (cT3-4N0 or cTanyN1-2) and synchronous resectable liver-limited metastases (cM1a) were randomly assigned to receive either preoperative treatments of induction CapeOx, followed by chemoradiotherapy with CapeOx (CapeOx-RT) (arm A) or CapeOx-RT alone (arm B). Induction CapeOx consisted of oxaliplatin 130 mg/m² on day 1 and capecitabine 1000 mg/m² twice daily on days 1 to 14, every 3 weeks for 2 cycles; CapeOx-RT consisted of radiotherapy with 45 Gy/25 daily fractions±5.4 Gy/3 fractions, oxaliplatin 50 mg/m² weekly for 5 weeks, and capecitabine 825 mg/m² twice daily on days 1 to 38. Total mesorectal excision and simultaneous liver metastasectomy were planned within 6 weeks after completion of preoperative treatments. The primary endpoint was R0 resection rate of both the primary tumor and LMs.

Results:

Thirty-eight patients were randomly assigned to the present study, 18 to arm A and 20 to arm B. The overall R0 resection rate for both the primary tumor and LMs was 77.8% in arm A and 70.0% in arm B (P=0.72). The median progression-free survival was 14.2 versus 15.1 months (P=0.422) and the 3-year overall survival rate was 75.0% versus 88.8% (P=0.29), respectively.

Conclusions:

Both treatment strategies showed considerable R0 resection rates; however, further study will be warranted to apply these intensified strategies in clinical practice.

Centralization of Liver Cancer Surgery and Impact on Multidisciplinary Teams Working on Stage IV Colorectal Cancer

Surgical resection is the most effective treatment approach for colorectal liver metastases but only a minority of patients is suitable for upfront surgery. The treatment strategies of stage IV colorectal cancer have shifted towards a continuum of care in which medical and surgical treatment combinations are tailored to the clinical setting of the individual patient. The optimization of treatment through appropriate decision-making and multimodal therapy for stage IV colorectal cancer require a joint multidisciplinary meeting in a centralized liver cancer unit.

Clinical Impact of Preoperative Chemotherapy on Microscopic Cancer Spread Surrounding Colorectal Liver Metastases

BACKGROUND

A potentially favorable effect of chemotherapy on the incidence of micrometastases has been reported in patients with colorectal liver metastases (CLMs); however, the actual influence of chemotherapy on the distribution of micrometastases and surgical curability remains unclear.

METHOD

The clinical impact of preoperative chemotherapy on the incidence and distribution of micrometastases was assessed in 191 patients with 357 CLM nodules. Potential radiologic measures for predicting the extent of microscopic cancer spread and surgical curability were then sought among the size-based and non-size-based radiologic response criteria.

RESULTS

Multivariate analysis estimated a reduced incidence of micrometastases in patients receiving preoperative chemotherapy (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.26-0.76, p = 0.003). Furthermore, the addition of biologic agents to the preoperative chemotherapy regimen was correlated with a reduced incidence of microscopic cancer spread beyond a width of 1 mm from the margin of the main tumor (OR 0.28, 95% CI 0.11-0.74, p = 0.010 for bevacizumab; and OR 0.29, 95% CI 0.09-0.99, p = 0.048 for anti-epidermal growth factor receptor antibody). Receiver operating characteristic analyses revealed that the computed tomography (CT) morphologic response showed a moderate predictive power for the distribution of micrometastases, with an area under the curve of 0.687, while size-based response criteria were not reliable for estimating the extent of microscopic cancer spread.

CONCLUSION

Notwithstanding the potential selection of patients after preoperative chemotherapy, the incidence and distribution of micrometastases may be reduced by preoperative chemotherapy. CT morphologic response may be a reliable predictor of both the degree of microscopic cancer spread and the curability of surgery.

Can molecular biomarkers replace a clinical risk score for resectable colorectal liver metastasis?

In resectable colorectal liver metastasis (CRLM) the role and use of molecular biomarkers is still controversial. Several biomarkers have been linked to clinical outcomes in CRLM, but none have so far become routine for clinical decision making. For several reasons, the clinical risk score appears to no longer hold the same predictive value. Some of the reasons include the ever expanding indications for liver resection, which now increasingly tend to involve extrahepatic disease, such as lung metastases (both resectable and non-resectable) and the shift in indication from “what is taken out” (e.g., how much liver has to be resected) to “what is left behind” (that is, how much functional liver tissue the patient has after resection). The latter is amenable to modifications by using adjunct techniques of portal vein embolization and the associating liver partition and portal vein ligation for staged hepatectomy techniques to expand indications for liver resection. Added to this complexity is the increasing number of molecular markers, which appear to hold important prognostic and predictive information, for which some will be discussed here. Beyond characteristics of tissue-based genomic profiles will be liquid biopsies derived from circulating tumor cells and cell-free circulating tumor DNA in the blood. These markers are present in the peripheral circulation in the majority of patients with metastatic cancer disease. Circulating biomarkers may represent more readily available methods to monitor, characterize and predict cancer biology with future implications for cancer care.

Liver Metastases in Colorectal Cancer

Resection of colorectal liver metastases is a treatment standard because patients experience long-term disease-free survival or are even cured after undergoing this procedure. Improved surgical techniques for liver resection in combination with downsizing liver metastases by chemotherapy, interventions to induce liver hypertrophy before resection, and the use of ablative techniques have allowed us to expand the indications for liver surgery and local treatment in situations with limited metastatic colorectal cancer. Resectability and identification of patients who might benefit from liver surgery and local ablative techniques are key factors for the treatment of patients with colorectal cancer. Despite the wide acceptance of liver surgery and ablative techniques, there are many open questions on the management of limited metastatic disease, such as which patients benefit from an aggressive surgical approach, what the indications for ablative and other local techniques are, and what the role of chemotherapy is for patients with resectable or resected disease. Unfortunately, results of randomized trials are only available for a limited number of these questions.

Colorectal Liver Metastases: A Critical Review of State of the Art

BACKGROUND

Over 50% of patients with colorectal cancer will develop liver metastases. Only a minority of patients present with technically resectable disease. Around 40% of those undergoing surgical resection are alive five years after their diagnosis compared with less than 1% for those with disseminated disease treated with systemic chemotherapy. Surgical resection remains the only possibility for long-term survival for these patients and great efforts have been made to increase the rates of resection whilst improving long-term outcomes.

SUMMARY

This review considers current technical and oncological criteria for resection, as well as targeted approaches to stratify underlying tumor biology in order to better predict long-term benefit. The role of neoadjuvant and perioperative systemic chemotherapy is critically reviewed, with suggestions for patient stratification in order to identify those who are likely to derive the greatest benefit. The key role of multidisciplinary assessment and decision making for these complex patients is also discussed.

KEY MESSAGES

Surgery remains the optimal treatment for colorectal liver metastases (CRLM). Despite the curative intent of surgical resection, the majority of patients develop recurrence. Surgical strategies should therefore be adopted to maximize the potential for repeat resections in the event of recurrence. Although a number of preoperative prognostic markers have been identified, none are absolute contraindications to resection. In order to reduce postoperative recurrence, neo-adjuvant chemotherapy is now the standard of care in a number of countries. The evidence base for this approach is contentious, and the potential benefit of such a strategy is likely to be greatest in patients with high oncological risk disease. Multidisciplinary care is essential to ensure the optimal management of these complex patients. In addition, all patients with CRLM should be discussed with specialist hepatobiliary surgeons.

Liver surgery for metastatic colorectal cancer: the surgical oncologist perspective

Neoadjuvant/conversion chemotherapy has emerged as an indispensable tool to achieve resectability of initially unresectable metastatic colorectal cancer and improves oncological outcomes. In parallel, surgical strategy has adopted a more aggressive treatment approach to achieve complete tumor clearance. However, chemotherapy affects liver function and combined with extensive liver resection, morbidity has increased, thereby compromising oncological outcome. There is an imperative need for careful patient selection to optimize patient management. In this review, we discuss available evidence and indications for neoadjuvant treatment in the management of colorectal cancer liver metastases, on preoperative patient selection and identification of high-risk patients, potential treatment strategies to promote postoperative liver regeneration to avoid postoperative morbidity and potentially deleterious side effects of these therapies on tumor growth.

Resection of Liver Metastases in Colorectal Cancer in the Era of Expanding Systemic Therapy

About 25% of patients with colorectal cancer develop liver metastases after resection of the primary tumor, and surgical resection of the metastases offers the only opportunity for long-term survival. However, only 20% of patients present with resectable disease. Deciding which patients should be offered surgery, and which should receive additional treatment in the form of perioperative chemotherapy, is complex. For the majority of patients who present with technically irresectable liver-limited disease, systemic downsizing chemotherapy offers the only opportunity to reach surgery and potential cure. Molecular analysis of tumor tissue is improving patient stratification, allowing more appropriate treatment selection, but is not yet a regular part of clinical practice. Decision making is limited by a lack of clear prospective evidence, and so multidisciplinary team assessment is essential to optimize outcomes.

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OLIGOMETASTASIS AND OLIGOPROGRESSION

Oligometastic progression (or solitary metastases) can justify ablative treatment for metastatic treatment. When such a strategy is discussed, it is important to notice that definition of oligometastases is not consensual both in terms of clinical presentation than on the biological basis. Does a specific biological background truly exist and are there markers that could predict for additional occult disease and its oligo or polymetastatic profile in individuals with demonstrated oligometastasis. This article provides a summary of the state of the art in this field and highlights some current areas of controversies.

Patterns of progression, treatment of progressive disease and post-progression survival in the New EPOC study

BACKGROUND

The addition of cetuximab (CTX) to perioperative chemotherapy (CT) for operable colorectal liver metastases resulted in a shorter progression-free survival. Details of disease progression are described to further inform the primary study outcome.

METHODS

A total of 257 KRAS wild-type patients were randomised to CT alone or CT with CTX. Data regarding sites and treatment of progressive disease were obtained for the 109 (CT n=48, CT and CTX n=61) patients with progressive disease at the cut-off date for analysis of November 2012.

RESULTS

The liver was the most frequent site of progression (CT 67% (32/48); CT and CTX 66% (40/61)). A higher proportion of patients in the CT and group had multiple sites of progressive disease (CT 8%, 4/48; CT and CTX 23%, 14/61 P=0.04). Further treatment for progressive disease is known for 84 patients of whom 69 received further CT, most frequently irinotecan based. Twenty-two patients, 11 in each arm, received CTX as a further line agent.

CONCLUSIONS

Both the distribution of progressive disease and further treatment are as expected for such a cohort. The pattern of disease progression seen is consistent with failure of systemic micrometastatic disease control rather than failure of local disease control following liver surgery.

Systematic review of systemic adjuvant, neoadjuvant and perioperative chemotherapy for resectable colorectal-liver metastases

INTRODUCTION

The role of systemic chemotherapy in patients with resectable colorectal liver metastases (CRLM) is ambiguous. The aim of this review was to compare the outcomes of regimens using systemic neoadjuvant, adjuvant or perioperative (combination of pre and postoperative) chemotherapy, for the treatment of resectable CRLM.

METHODS

MEDLINE was searched for articles investigating the use of chemotherapy for adults with resectable CRLM. Randomized controlled trials reporting overall survival (OS), disease-free survival (DFS) and grade 3-4 adverse events (AEs) were screened for inclusion. PROSPERO record: CRD42015020609.

RESULTS

Four trials met the inclusion criteria (1098 patients). No significant improvement in median OS was achieved with chemotherapy/surgery compared with surgery-alone. Two trials demonstrated a significant improvement in DFS with chemotherapy/surgery compared to surgery-alone (Hazard ratio 0.78 (0.61-0.99) p = 0.04 and HR 0.66 (0.46-0.96) p = 0.03). Fluorouracil/folinic acid alone had a lower incidence of AEs than combination therapies, and the addition of cetuximab shortened DFS in one trial (HR 1.48 (1.04-2.12) p = 0.03).

CONCLUSION

There is a lack of adequately powered trials of chemotherapy in combination with liver resection for CRLM, partly due to difficulties in recruitment. In an unselected patient group, FOLFOX in combination with liver resection appears to improve DFS compared to surgery-alone, but trials are underpowered for OS. Future trials will require prospective stratification of patients based on biomarkers predictive of response.

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.

Biologic therapies in colorectal cancer: indications and contraindications

The role of antiangiogenic and anti-epidermal growth factor receptor (EGFR) agents has been investigated extensively in colorectal cancer in the palliative, adjuvant, and neoadjuvant settings. Although the role of biologic agents has become well-defined in the first, second, and subsequent lines of treatment of metastatic colorectal cancer (mCRC), considerable debate continues around the optimal sequencing and around optimal patient selection. The benefits from integrating bevacizumab or cetuximab in the adjuvant setting have been investigated in several randomized phase III clinical trials in stage II/III disease, all with disappointing results. Neoadjuvant approaches incorporating biologic therapy in patients with liver metastatic disease have led to mixed results. Although the current evidence does suggest increased down-staging and increased resectability with the addition of cetuximab in patients with initially unresectable or borderline resectable liver metastases, a positive effect of anti-EGFR therapy on the overall survival (OS) in this setting is not conclusive. Patients with resectable liver metastases derive no benefit and may experience potential harm from the addition of cetuximab to neoadjuvant chemotherapy. Similarly, there is neither rationale nor adequate data to support the addition of bevacizumab to neoadjuvant chemotherapy in patients with resectable liver metastases. In this review, we examine the role of antiangiogenesis and anti-EGFR therapies across the spectrum of adjuvant, neoadjuvant, and metastatic disease.