Colorectal liver metastases: surgery versus thermal ablation (COLLISION) - a phase III single-blind prospective randomized controlled trial

Synchronous Liver Resection, Cytoreductive Surgery, and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Liver and Peritoneal Metastases: A Systematic Review and Meta-analysis

BACKGROUND

Synchronous liver resection, cytoreductive surgery, and hyperthermic intraperitoneal chemotherapy for colorectal liver and peritoneal metastases have traditionally been contraindicated. More recent clinical practice has begun to promote this aggressive treatment in select patients.

OBJECTIVE

This study aimed to investigate the perioperative and oncological outcomes of patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, with and without liver resection, in the management of metastatic colorectal cancer.

DATA SOURCES

Medline, Embase, and Cochrane Library databases were searched up to July 2020.

STUDY SELECTION

Cohort studies comparing outcomes following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy with and without liver resection for metastatic colorectal cancer were reviewed. No randomized controlled trials were available.

INTERVENTION

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy with or without synchronous liver resection were compared.

MAIN OUTCOME MEASURES

The primary outcome measures were perioperative mortality and major morbidity. Secondary outcomes included 3- and 5-year overall survival and 1- and 3-year disease-free survival.

RESULTS

Fourteen studies fitted the inclusion criteria, with 8 studies included in the meta-analysis. On pooled analysis, there was no significant difference in perioperative morbidity and mortality between the two groups. Patients that underwent concomitant liver resection had worse 1- and 3-year disease-free survival and 3- and 5-year overall survival.

LIMITATIONS

Only a limited number of studies were available, with a moderate degree of heterogeneity.

CONCLUSIONS

The addition of synchronous liver resection to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for the treatment of resectable metastatic colorectal cancer was not associated with increased perioperative major morbidity and mortality in comparison with cytoreduction and hyperthermic intraperitoneal chemotherapy alone. However, the presence of liver metastases was associated with inferior disease-free and overall survival. These data support the continued practice of liver resection, cytoreductive surgery, and hyperthermic intraperitoneal chemotherapy in the management of select patients with such stage IV disease.

Is percutaneous destruction of a solitary liver colorectal metastasis as effective as a resection?

Backgrounds/Aims

Surgical resection remains the gold standard in the treatment of colorectal liver metastasis. However, when a patient presents with a deep solitary colorectal liver metastasis (S-CLM), the balance between the hepatic volume sacrificed and the S-CLM volume is sometimes clearly unappropriated. Thus, alternatives to surgery, such as operative and percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA), have been developed. This study aimed to identify the prognostic factors affecting survival of patients with S-CLM who undergo curative-intent liver resection or local destruction (RFA or MWA).

Methods

We retrospectively identified 211 patients with synchronous or metachronous S-CLM who underwent either surgical resection (n=182) or local destruction (RFA or MWA; n=29) according to the S-CLM size, location, and surrounding Glissonian structures.

Results

Patients who underwent RFA or MWA had S-CLM of a smaller size than those who underwent resection (mean 19.7 vs. 37.3 mm, p<.01). The 1-, 3-, and 5-year overall survival (OS) rates were 97.4%, 84.9%, and 74.9%, respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 77.9%, 47%, and 38.9%, respectively. S-CLM located in the left liver (p=.04), S-CLM KRAS mutation (p<.01), and extra-hepatic recurrence (p<.01) were identified as independent poor risk factors for overall survival (OS); the OS and DFS were comparable in patients with surgical procedure or percutaneous MWA.

Conclusions

In eligible S-CLM cases, percutaneous MWA seems to be as oncologically efficient as surgical resection and should be include in the decision-tree for treatment strategies.

Optimizing Loco Regional Management of Oligometastatic Colorectal Cancer: Technical Aspects and Biomarkers, Two Sides of the Same Coin

Colorectal cancer (CRC) is the third most common cancer worldwide and has a high rate of metastatic disease which is the main cause of CRC-related death. Oligometastatic disease is a clinical condition recently included in ESMO guidelines that can benefit from a more aggressive locoregional approach. This review focuses the attention on colorectal liver metastases (CRLM) and highlights recommendations and therapeutic locoregional strategies drawn from the current literature and consensus conferences. The different percutaneous therapies (radiofrequency ablation, microwave ablation, irreversible electroporation) as well as trans-arterial approaches (chemoembolization and radioembolization) are discussed. Ablation margins, the choice of the imaging guidance as well as characteristics of the different ablation techniques and other technical aspects are analyzed. A specific attention is then paid to the increasing role of biomarkers (in particular molecular profiling) and their role in the selection of the proper treatment for the right patient. In conclusion, in this review an up-to-date state of the art of the application of locoregional treatments on CRLM is provided, highlighting both technical aspects and the role of biomarkers, two sides of the same coin.

Limited Liver or Lung Colorectal Cancer Metastases. Systemic Treatment, Surgery, Ablation or SBRT

The prognosis for oligometastatic colorectal cancer has improved in recent years, mostly because of recent advances in new techniques and approaches to the treatment of oligometastases, including new surgical procedures, better systemic treatments, percutaneous ablation, and stereotactic body radiation therapy (SBRT). There are several factors to consider when deciding on the better approach for each patient: tumor factors (metachronous or synchronous metastases, RAS mutation, BRAF mutation, disease-free interval, size and number of metastases), patient factors (age, frailty, comorbidities, patient preferences), and physicians' factors (local expertise). These advances have presented major challenges and opportunities for oncologic multidisciplinary teams to treat patients with limited liver and lung metastases from colorectal cancer with a curative intention. In this review, we describe the different treatment options in patients with limited liver and lung metastases from colorectal cancer, and the possible combination of three approaches: systemic treatment, surgery, and local ablative treatments.

Percutaneous ablation of post-surgical solitary early recurrence of colorectal liver metastases is an effective "test-of-time" approach

Standard treatment of early recurrence of colorectal liver metastases (CLM) after liver resection (LR) is chemotherapy followed by loco-regional therapy. We reviewed the outcome of a different strategy ("test-of-time" approach): upfront percutaneous ablation without chemotherapy. Twenty-six consecutive patients with early solitary liver-only recurrence amenable to both resection and ablation (< 30 mm, distant from vessels) undergone "test-of-time" approach were analyzed. Early recurrence had a median size of 17 mm and occurred after a median interval from LR of 4 months. Primary efficacy rate of ablation was 100%. Five patients are alive and disease-free after a mean follow-up of 46 months. Five patients had local-only recurrence; all had repeat treatment (LR = 4; Ablation = 1) without chemotherapy. Local recurrence risk was associated with incomplete ablation of 1-cm thick peritumoral margin. The remaining 16 patients had non-local recurrence, 13 early after ablation. Overall, six (23%) patients had ablation as unique treatment and 13 (50%) avoided or postponed chemotherapy (mean chemotherapy-free interval 33.5 months). Ablation without chemotherapy of early liver-only recurrence is a reliable "test-of-time" approach. It minimized the invasiveness of treatment with good effectiveness and high salvageability in case of local failure, avoided worthless surgery, and saved chemotherapy for further disease progression.

Outcomes following synchronous liver resection, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal liver and peritoneal metastases: A bi-institutional study

PURPOSE

Synchronous liver resection, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal liver (CRLM) and peritoneal metastases (CRPM) has traditionally been contraindicated. However, latest practice promotes specialist, multidisciplinary-led consideration for select patients. This study aimed to evaluate the perioperative and oncological outcomes of synchronous resection in the management of CRLM and CRPM from two tertiary referral centres.

METHOD

This bi-institutional, retrospective, cohort study included patients undergoing simultaneous liver resection, CRS and HIPEC for metastatic colorectal cancer from 2013 to 2020. Patients treated with ablative liver techniques, staged operative approaches and extra abdominal disease were excluded. Overall survival (OS) and disease-free survival (DFS) rates were assessed. Univariate and multivariate analyses identified variables associated with survival and major morbidity (Clavien-Dindo grade III/IV).

RESULTS

Twenty-three patients were included. The median peritoneal carcinomatosis index (PCI) was 9 (range 0-22). There were two major liver resections and 21 minor resections. CC-0 resections were achieved in all patients. Major morbidity occurred in 7 patients. There were no deaths at 90 days. PCI was independently associated with morbidity (p = 0.04). PCI >10 (p = 0.069), major morbidity (p = 0.083) and presence of KRAS mutation (p = 0.052) approached significance for poor OS. Median follow up was 21 months (4-54 months). Median OS was 37 months, 3-year survival 54%, and median DFS 18 months.

CONCLUSION

Synchronous liver resection, cytoreductive surgery and HIPEC is feasible in selected patients with low-volume CRPM and CRLM. Increasing PCI is associated with postoperative major morbidity, and should be considered during operative planning.

Cost-Effectiveness Analysis of Local Ablation and Surgery for Liver Metastases of Oligometastatic Colorectal Cancer

BACKGROUND

Colorectal cancer is among the most prevalent cancer entities worldwide, with every second patient developing liver metastases during their illness. For local treatment of liver metastases, a surgical approach as well as ablative treatment options, such as microwave ablation (MWA) and radiofrequency ablation (RFA), are available. The aim of this study is to evaluate the cost-effectiveness of RFA, MWA and surgery in the treatment of liver metastases of oligometastatic colorectal cancer (omCRC) that are amenable for all investigated treatment modalities.

METHODS

A decision analysis based on a Markov model assessed lifetime costs and quality-adjusted life years (QALY) related to the treatment strategies RFA, MWA and surgical resection. Input parameters were based on the best available and most recent evidence. Probabilistic sensitivity analyses (PSA) were performed with Monte Carlo simulations to evaluate model robustness. The percentage of cost-effective iterations was determined for different willingness-to-pay (WTP) thresholds.

RESULTS

The base-case analysis showed that surgery led to higher long-term costs compared to RFA and MWA (USD 41,848 vs. USD 36,937 vs. USD 35,234), while providing better long-term outcomes than RFA, yet slightly lower than MWA (6.80 vs. 6.30 vs. 6.95 QALYs for surgery, RFA and MWA, respectively). In PSA, MWA was the most cost-effective strategy for all WTP thresholds below USD 80,000 per QALY.

CONCLUSIONS

In omCRC patients with liver metastases, MWA and surgery are estimated to provide comparable efficacy. MWA was identified as the most cost-effective strategy in intermediate resource settings and should be considered as an alternative to surgery in high resource settings.

Evolution of Surgical Treatment of Colorectal Liver Metastases in the Real World: Single Center Experience in 1212 Cases

BACKGROUND

In recent years, the treatment of colorectal liver metastases (CRLM) has undergone significant evolution thanks to technical improvements as well as oncological advances, which have been the subject of targeted studies aimed at understanding the details of this heterogeneous disease. The purpose of this study is to put together pieces of this complex scenario by providing an overview of the evolution that has occurred in the context of a single center within a multidisciplinary management approach.

METHODS

Between 2005 and 2020, 1212 resections for CRLM were performed at the Hepatobiliary Surgery Division of San Raffaele Hospital, Milan. The series was divided into three historical periods, which were compared in terms of disease characteristics and short- and long-term outcomes: Period 1, 2005-2009 (293 cases); Period 2, 2010-2014 (353 cases); Period 3, 2015-2020 (566 cases). The trends for surgical technical complexity, oncological burden of the disease, use of the laparoscopic approach and use of techniques for hepatic hypertrophy were analyzed year by year. Uni- and multivariate analyses were performed to identify factors associated with inclusion to a laparoscopic approach and with long-term prognosis.

RESULTS

The number of resections performed over the years progressively increased, with an increase in the number of cases with a high Clinical Risk Score and a high profile of technical complexity. The proportion of cases performed laparoscopically increased, but less rapidly compared to other malignant tumors. The risk of postoperative morbidity and mortality was similar in the three analyzed periods. Long-term survival, stratified by Clinical Risk Score, improved in Period 3, while overall survival remained unchanged.

CONCLUSION

The cultural background, the maturation of technical expertise and the consolidation of the multidisciplinary team have resulted in safe expansion of the possibility to offer a curative opportunity to patients, while continuously implementing into clinical practice evidence provided by the literature.

Long-term outcome of Stereotactic Body Radiation Therapy for patient with unresectable liver metastases from colorectal cancer

PURPOSE

To investigate clinical outcome and predicting factors of local failures in patients with colorectal cancer treated for unresectable liver metastases with stereotactic body radiation therapy (SBRT).

METHODS AND MATERIALS

We restrospectively reviewed the medical records of 67 patients treated with the Cyberknife SBRT system for 99 hepatic metastases between January 2007 and December 2015 in our center. In total, 37.5 to 54.0Gy in 3 to 5 fractions were prescribed to the 80% isodose line. Local control (LC), intrahepatic progression incidence, Progression-Free Survival (PFS), Overall Survival (OS) and toxicity were evaluated.

RESULTS

The median follow-up was 47 months (IQR, 28-59 months). The median OS was 53 months, the 2-year OS and PFS rates were 81.4% and 54.0%. The 1- and 2-year LC rates were 86.6% and 72.4%. In the multivariate analysis, the degree of differentiation was the only prognostic factor for LC (HR 0.31, 95% CI, 0.10-0.98, P=0.046). Margin expansion>5mm was not associated with a better LC (HR 0.72, 95% CI, 0.38-1.37, P=0.317). Performans Status≥2 (HR 3.27, 95% CI, 1.07-9.98, P=0.038), chemotherapy for metastases before SBRT (HR 0.36, 95% CI, 0.18-0.75, P=0.006) and regional lymph node at diagnosis (HR 2.19, 95% CI, 1.09-4.43, P=0.029) were independent prognostic factors for OS. We report 2 cases of grade≥3 toxicity (3.0%) - one grade 3 acute nausea and one grade 3 late gastric ulcer.

CONCLUSION

Stereotactic body radiation therapy is an effective and well-tolerated treatment that allow high LC for liver metastases from colorectal cancer during the first two years. A prescription dose of 45Gy in 3 fractions to the 80% isodose line with a risk adapted schedule to respect Organ At Risk constraints allows a low rate of toxicity.

The Role of Neoadjuvant Chemotherapy in Repeat Local Treatment of Recurrent Colorectal Liver Metastases: A Systematic Review and Meta-Analysis

The additive value of neoadjuvant chemotherapy (NAC) prior to repeat local treatment of patients with recurrent colorectal liver metastases (CRLM) is unclear. A systematic search was performed in PubMed, Embase, Web of Science, and an additional search in Google Scholar to find articles comparing repeat local treatment by partial hepatectomy and/or thermal ablation with versus without NAC. The search included randomized trials and comparative observational studies with univariate/multivariate analysis and/or matching as well as (inter)national guidelines assessed using the AGREE II instrument. The search identified 21,832 records; 172 were selected for full-text review; 20 were included: 20 comparative observational studies were evaluated. Literature to evaluate the additive value of NAC prior to repeat local treatment was limited. Outcomes of NAC were often reported as subgroup analyses and reporting of results was frequently unclear. Assessment of the seven studies that qualified for inclusion in the meta-analysis showed conflicting results. Only one study reported a significant difference in overall survival (OS) favoring NAC prior to repeat local treatment. However, further analysis revealed a high risk for residual bias, because only a selected group of chemo-responders qualified for repeat local treatment, disregarding the non-responders who did not qualify. All guidelines that specifically mention recurrent disease (3/3) recommend repeat local treatment; none provide recommendations about the role of NAC. The inconclusive findings of this meta-analysis do not support recommendations to routinely favor NAC prior to repeat local treatment. This emphasizes the need to investigate the additive value of NAC prior to repeat local treatment of patients with recurrent CRLM in a future phase 3 randomized controlled trial (RCT).

Therapeutic Approaches for Metastases from Colorectal Cancer and Pancreatic Ductal Carcinoma

Metastasis is the process of dissemination of a tumor, whereby cells from the primary site dislodge and find their way to other tissues where secondary tumors establish. Metastasis is the primary cause of death related to cancer. This process warrants changes in original tumoral cells and their microenvironment to establish a metastatic niche. Traditionally, cancer therapy has focused on metastasis prevention by systematic treatments or direct surgical re-sectioning. However, metastasis can still occur. More recently, new therapies direct their attention to targeting cancer stem cells. As they propose, these cells could be the orchestrators of the metastatic niche. In this review, we describe conventional and novel developments in cancer therapeutics for liver and lung metastasis. We further discuss the resistance mechanisms of targeted therapy, the advantages, and disadvantages of diverse treatment approaches, and future novel strategies to enhance cancer prognosis.

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.

Strategies for the delay of surgery in the management of resectable hepatobiliary malignancies during the COVID-19 pandemic

Objective

We aimed to review data about delaying strategies for the management of hepatobiliary cancers requiring surgery during the covid-19 pandemic.

Background

Given the covid-19 pandemic, many jurisdictions, to spare resources, have limited access to operating rooms for elective surgical activity, including cancer, thus forcing deferral or cancellation of cancer surgeries. Surgery for hepatobiliary cancer is high-risk and particularly resource-intensive. Surgeons must critically appraise which patients will benefit most from surgery and which ones have other therapeutic options to delay surgery. Little guidance is currently available about potential delaying strategies for hepatobiliary cancers when surgery is not possible.

Methods

An international multidisciplinary panel reviewed the available literature to summarize data relating to standard-of-care surgical management and possible mitigating strategies to be used as a bridge to surgery for colorectal liver metastases, hepatocellular carcinoma, gallbladder cancer, intrahepatic cholangiocarcinoma, and hilar cholangiocarcinoma.

Results

Outcomes of surgery during the covid-19 pandemic are reviewed. Resource requirements are summarized, including logistics and adverse effects profiles for hepatectomy and delaying strategies using systemic, percutaneous and radiation ablative, and liver embolic therapies. For each cancer type, the long-term oncologic outcomes of hepatectomy and the clinical tools that can be used to prognosticate for individual patients are detailed.

Conclusions

There are a variety of delaying strategies to consider if availability of operating rooms decreases. This review summarizes available data to provide guidance about possible delaying strategies depending on patient, resource, institution, and systems factors. Multidisciplinary team discussions should be leveraged to consider patient- and tumour-specific information for each individual case.

Impact of patient, primary tumor and metastatic pattern including tumor location on survival in patients undergoing ablation or resection for colorectal liver metastases: A population-based national cohort study

INTRODUCTION

Selecting the optimal treatment strategy for patients with colorectal liver metastases (CRLM) aim to improve survival for the total cohort. Following the introduction of laparoscopic resections and ablation, localization may direct choice of method. The aim with this study was to re-evaluate prognostic factors that should be considered at the preoperative multidisciplinary tumor board, based on a national population cohort.

MATERIALS AND METHODS

A national cohort with radically operated colorectal cancer in 2009-2013, also treated for CRLM was identified in Swedish national registries. Prognostic factors were identified and evaluated in multivariable analyses.

RESULTS

1200 patients treated with resection and 125 with ablation only were included in the study cohort. Relative five-year survival was 54.7% (50.9%-58.4%) and 32.0% (22.4%-41.9%), respectively). High age, acute surgery and complications at time of primary tumor resection remained important risk factors at liver surgery, as well as the primary tumor characteristics; vascular invasion and high lymph node ratio. As for metastatic pattern; tumor size, location in segment 4, 6, 7 or 8, multiple metastatic sites and progress after preoperative chemotherapy were significant risk factors. In multivariate analyses, ablation therapy doubled the risk of death within 5 years. This strong negative impact was confirmed in a weighted propensity score analysis (HR = 2.1 (95 % CI 1.5 -3.0)).

CONCLUSION

Segmental localization and tumor size were prognostic factors but also patient and primary tumor factors significantly impacted survival after intervention for CRLM. Long-term survival was significantly lower after ablation therapy compared to surgical resection.

Resectability and Ablatability Criteria for the Treatment of Liver Only Colorectal Metastases: Multidisciplinary Consensus Document from the COLLISION Trial Group

The guidelines for metastatic colorectal cancer crudely state that the best local treatment should be selected from a ‘toolbox’ of techniques according to patient- and treatment-related factors. We created an interdisciplinary, consensus-based algorithm with specific resectability and ablatability criteria for the treatment of colorectal liver metastases (CRLM). To pursue consensus, members of the multidisciplinary COLLISION and COLDFIRE trial expert panel employed the RAND appropriateness method (RAM). Statements regarding patient, disease, tumor and treatment characteristics were categorized as appropriate, equipoise or inappropriate. Patients with ECOG≤2, ASA≤3 and Charlson comorbidity index ≤8 should be considered fit for curative-intent local therapy. When easily resectable and/or ablatable (stage IVa), (neo)adjuvant systemic therapy is not indicated. When requiring major hepatectomy (stage IVb), neo-adjuvant systemic therapy is appropriate for early metachronous disease and to reduce procedural risk. To downstage patients (stage IVc), downsizing induction systemic therapy and/or future remnant augmentation is advised. Disease can only be deemed permanently unsuitable for local therapy if downstaging failed (stage IVd). Liver resection remains the gold standard. Thermal ablation is reserved for unresectable CRLM, deep-seated resectable CRLM and can be considered when patients are in poor health. Irreversible electroporation and stereotactic body radiotherapy can be considered for unresectable perihilar and perivascular CRLM 0-5cm. This consensus document provides per-patient and per-tumor resectability and ablatability criteria for the treatment of CRLM. These criteria are intended to aid tumor board discussions, improve consistency when designing prospective trials and advance intersociety communications. Areas where consensus is lacking warrant future comparative studies.

CIRSE Standards of Practice on Thermal Ablation of Liver Tumours

This CIRSE Standards of Practice document reviews current literature and provides best practices for image guided thermal ablation of liver tumours, including radiofrequency, microwave and cryoablation techniques.

Thermal Ablation versus SBRT in liver tumours: pros and cons

Non-surgical locally ablative treatments for primary liver cancer and liver metastases represent an effective therapeutic choice when surgery cannot be performed or is not indicated. Thermal ablative employing electric currents or electromagnetic fields have historically played an important role in this setting. Radiotherapy, in the last decades, due to a series of important technological development, has become an attractive option for the treatment of liver tumours, especially with the introduction of Stereotactic Body Radiotherapy. Published literature so far evidenced both for radiotherapy and thermal ablative techniques a benefit in terms of local control and other oncological outcomes; however, no direct prospective comparison between the two techniques have been published so far. The aim of this review is to summarize the technical and clinical implications of these treatment modalities and to identify criteria to allocate patients to one or another option in consideration of the expected efficacy. The main features and critical aspects of both thermoablative techniques and external beam radiation will also be covered in the present paper.

Hepatic Ablation Promotes Colon Cancer Metastases in an Immunocompetent Murine Model

OBJECTIVE

To determine the impact of radiofrequency (RF) and microwave (MW) energy compared to direct cautery on metatstatic colon cancer growth.

BACKGROUND

Hepatic ablation with MW and RF energy creates a temperature gradient around a target site with temperatures known to create tissue injury and cell death. In contrast, direct heat application (cautery) vaporizes tissue with a higher site temperature but reduced heat gradient on surrounding tissue. We hypothesize that different energy devices create variable zones of sublethal injury that may promote tumor recurrence. To test this hypothesis we applied MW, RF, and cautery to normal murine liver with a concomitant metastatic colon cancer challenge.

METHODS

C57/Bl6 mice received hepatic thermal injury with MW, RF, or cautery to create a superficial 3-mm lesion immediately after intrasplenic injection of 50K MC38 colon cancer cells. Thermal imaging recorded tissue temperature during ablation and for 10 seconds after energy cessation. Hepatic tumor location and volume was determined at day 7.

RESULTS

Cautery demonstrated the highest maximum tissue temperatures (129°C) with more rapid return to baseline compared to MW or RF energy. All mice had metastasis at the ablation site. Mean tumor volume was significantly greater in the MW (95.3 mm; P = 0.007) and RF (55.7 mm; P = 0.015) than cautery (7.13 mm). There was no difference in volume between MW and RF energy (P = 0.2).

CONCLUSIONS

Hepatic thermal ablation promotes colon cancer metastasis at the injury site. MV and RF energy result in greater metastatic volume than cautery. These data suggest that the method of energy delivery promotes local metastasis.

Role of thermal ablation in the management of colorectal liver metastasis

With a recent randomized prospective trial revealing that thermal ablative therapy as local tumor control improved overall survival (OS) in patients with unresectable colorectal cancer liver metastases (CRLM), thermal ablation continues to remain as an important treatment option in this patient population. Our aim of this article is to review the current role of the ablative therapy in the management of CRLM patients. Main indications for thermal ablation include (I) unresectable liver lesions; (II) in combination with hepatectomy; (III) in patients with significant medical comorbidities or poor performance status (PS); (IV) a small (<3 cm) solitary lesion, which would otherwise necessitate a major liver resection; and (V) patient preference. There are several approaches and modalities for ablative therapy, including open, percutaneous, and laparoscopic approaches, as well as radiofrequency ablation (RFA) and microwave ablation (MWA). Each approach and ablation modality have its own pros and cons. Percutaneous and laparoscopic approaches are preferred due to minimally invasive nature, yet laparoscopic approach has more benefits from thorough intraoperative ultrasound (US) exam as well as complete peritoneal staging with laparoscopy. Similarly, whereas high local tumor failure rate has been a major concern with RFA, MWA or microwave thermosphere ablation (MTA) have demonstrated significantly improved local tumor control due to homogenous tissue heating, ability to reach higher tissue temperatures, and less susceptible to the "heat-sink" effect. Although liver resection is the standard of care for CRLM, there have been some retrospective studies demonstrating similar oncological outcome between ablative therapy and surgical resection in very selected populations with small (<3 cm) solitary CRLM. Lastly, ablative therapy and liver resection should not be mutually exclusive, especially in the management of bilobar liver metastases. Concomitant ablative therapy with hepatectomy may spare the patients from having two-stage hepatectomy with less morbidity. The role of the thermal ablation will continue to evolve in patients with resectable and ablatable lesions owing to newly emerging technology, in addition to new systemic treatment options, including immunotherapy for metastatic colorectal cancer (CRC).

Innovation and Future Perspectives in the Treatment of Colorectal Liver Metastases

Technological advances and investigation into tumor biology have enhanced treatments of patients with colorectal liver metastases (CLM). This article briefly summarizes paradigm shifts in treatments of this disease in the following 4 sections. (1) Small metastases: The treatment of multiple and small CLM has evolved from anatomic resection to parenchyma-sparing hepatectomy. Survival after parenchyma-sparing hepatectomy was similar to or better than anatomic resection. The use of preoperative chemotherapy may cause tumor disappearance. However, the use of fiducial markers may aid in intraoperative localization. Post-resection completion ablation is a new useful treatment concept. It was defined as percutaneous ablation under cross-sectional imaging guidance to eradicate CLM which were intentionally unresected during latest surgery. (2) Bilateral (bilobar) metastases: Two-stage hepatectomy (TSH) is a well-established approach for treating multiple bilateral CLM. The use of hybrid operating room accelerates this sequence because it allows first-stage hepatectomy, portal vein embolization, and computed tomography in one hospitalization. This accelerated TSH sequence enables the second-stage hepatectomy within 4 weeks compared to 8 weeks using conventional TSH sequence. (3) Synchronous lung metastases: For patients with synchronous liver and lung metastases, simultaneous surgical approach is feasible. Specifically, a transdiaphragmatic approach enables simultaneous resection of liver and lung metastases via one abdominal incision. (4) Multiple mutation: Somatic gene mutation testing is increasingly used to evaluate tumor biology. Mutations in TP53, RAS, and SMAD4 affect prognosis through three different signaling pathways of colorectal carcinogenesis. This information can be used to change clinical decision-making regarding surveillance intensity and treatments for liver recurrence.

Systematic review and meta-analysis of local ablative therapies for resectable colorectal liver metastases

INTRODUCTION

Local ablative therapies (LAT) have shown positive but heterogenous outcomes in the treatment of colorectal liver metastases (CRLM). The aim of this systematic review is to evaluate LAT and compare them with surgical resection.

METHODS

In accordance with PRISMA guidelines, Medline, EMBASE, Cochrane and Web of Science databases were searched for reports published before January 2019. We included papers assessing radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA) and electroporation (IRE) treating resectable CRLM with curative intention. We evaluated LAT related complications and oncological outcomes as tumour progression (LTP), disease-free survival (DFS) and overall survival (OS).

RESULTS

The literature search yielded 6767 records; 20 papers (860 patients) were included. No included studies related mortality with LAT. Median adverse events percentage was 7%: (8% RFA;7% MWA). Median 3y-DFS was 32% (24% RFA; 60% MWA); 5y-DFS was 27%: (18% RFA; 38.5% MWA). Median 3y-OS was 59% (60% RFA; 70% MWA; 34% CA), 5y-OS was 44.5% (43% RFA; 55% MWA; 20% CA). Surgical resection showed decreased LTP, improved DFS and OS than those reported with LAT, with RFA accounting for reduced 1y-DFS (RR 0.83, 95%CI 0.71-0.98), 3y-DFS (RR 0.5, 95%CI 0.33-0.76), 5y-DFS (RR 0.53, 95%CI 0.28-0.98) and 5y-OS (RR 0.76, 95%CI 0.58-0.98) in comparison with surgical resection.

CONCLUSIONS

Low quality evidence suggests that both RFA and MWA seem superior to CA. MWA presents similar adverse events when compared to RFA with a possible increase in DFS and OS. Surgical resection still seems to provide superior DFS and OS in comparison with LAT.

A Non-interventional Clinical Trial Assessing Immune Responses After Radiofrequency Ablation of Liver Metastases From Colorectal Cancer

Background: Radiofrequency ablation (RFA) is an established treatment option for malignancies located in the liver. RFA-induced irreversible coagulation necrosis leads to the release of danger signals and cellular content. Hence, RFA may constitute an endogenous in situ tumor vaccination, stimulating innate and adaptive immune responses, including tumor-antigen specific T cells. This may explain a phenomenon termed abscopal effect, namely tumor regression in untreated lesions evidenced after distant thermal ablation or irradiation. In this study, we therefore assessed systemic and local immune responses in individual patients treated with RFA.

Methods: For this prospective clinical trial, patients with liver metastasis from colorectal carcinoma (mCRC) receiving RFA and undergoing metachronous liver surgery for another lesion were recruited (n = 9) during a 5-year period. Tumor and non-malignant liver tissue samples from six patients were investigated by whole transcriptome sequencing and tandem-mass spectrometry, characterizing naturally presented HLA ligands. Tumor antigen-derived HLA-restricted peptides were selected by different predefined approaches. Further, candidate HLA ligands were manually curated. Peripheral blood mononuclear cells were stimulated in vitro with epitope candidate peptides, and functional T cell responses were assessed by intracellular cytokine staining. Immunohistochemical markers were additionally investigated in surgically resected mCRC from patients treated with (n = 9) or without RFA (n = 7).

Results: In all six investigated patients, either induced immune responses and/or pre-existing T cell immunity against the selected targets were observed. Multi-cytokine responses were inter alia directed against known tumor antigens such as cyclin D1 but also against a (predicted) mutation contained in ERBB3. Immunohistochemistry did not show a relevant influx of immune cells into distant malignant lesions after RFA treatment (n = 9) as compared to the surgery only mCRC group (n = 7).

Conclusions: Using an individualized approach for target selection, RFA induced and/or boosted T cell responses specific for individual tumor antigens were more frequently detectable as compared to previously published observations with well-characterized tumor antigens. However, the witnessed modest RFA-induced immunological effects alone may not be sufficient for the rejection of established tumors. Therefore, these findings warrant further clinical investigation including the assessment of RFA combination therapies e.g., with immune stimulatory agents, cancer vaccination, and/or immune checkpoint inhibitors.

Thermal Ablation of Metastatic Colon Cancer to the Liver

Colorectal cancer (CRC) is responsible for approximately 10% of cancer-related deaths in the Western world. Liver metastases are frequently seen at the time of diagnosis and throughout the course of the disease. Surgical resection is often considered as it provides long-term survival; however, few patients are candidates for resection. Percutaneous ablative therapies are also used in the management of this patient population. Different thermal ablation (TA) technologies are available including radiofrequency ablation, microwave ablation (MWA), laser, and cryoablation. There is growing evidence about the role of interventional oncology and image-guided percutaneous ablation in the management of metastatic colorectal liver disease. This article aims to outline the technical considerations, outcomes, and rational of TA in the management of patients with CRC liver metastases, focusing on the emerging role of MWA.

Ablation or Resection for Colorectal Liver Metastases? A Systematic Review of the Literature

Background: Successful use of ablation for small hepatocellular carcinomas (HCC) has led to interest in the role of ablation for colorectal liver metastases (CRLM). However, there remains a lack of clarity about the use of ablation for colorectal liver metastases (CRLM), specifically its efficacy compared with hepatic resection. Methods: A systematic review of the literature on ablation or resection of colorectal liver metastases was performed using MEDLINE, Cochrane Library, and Embase until December 2018. The aim of this study was to summarize the evidence for ablation vs. resection in the treatment of CRLM. Results: This review identified 1,773 studies of which 18 were eligible for inclusion. In the majority of the studies, overall survival (OS) and disease-free survival (DFS) were significantly higher and local recurrence (LR) rates were significantly lower in the resection groups. On subgroup analysis of solitary CRLM, resection was associated with improved OS, DFS, and reduced LR. Three series assessed the outcome of resection vs. ablation for technically resectable CRLM, and showed improved outcome in the resection group. In fact, there were no studies showing a survival advantage of ablation compared to resection in the treatment of CRLM. Conclusions: Resection remains the "gold standard" in the treatment of CRLM and should not be replaced by ablation at present. This review supports the use of ablation only as an adjunct to resection and as a single treatment option when resection is not safely possible.

Percutaneous stereotactic image-guided microwave ablation for malignant liver lesions

Thermal ablation has proven beneficial for hepatocellular carcinoma and possibly for colorectal liver metastases, but data is lacking for other liver metastases. Computer-assisted navigation can increase ablation efficacy and broaden its indications. We present our experience with percutaneous stereotactic image-guided microwave ablation (SMWA) for non-colorectal liver metastases (NCRLM), in form of a retrospective study including all SMWA for NCRLM from 2015 to 2017. Indication for SMWA was determined at a multidisciplinary tumorboard. End-points include recurrence, overall and liver-specific disease progression and complications. Twenty-three patients underwent 25 interventions for 40 lesions, including 17 neuroendocrine tumor, nine breast cancer, four sarcoma, two non-small cell lung cancer, three duodenal adenocarcinoma, one esophageal adenocarcinoma, one pancreatic adenocarcinoma, one ampullary carcinoma, one prostate carcinoma, and one renal cell carcinoma metastases. Median follow-up was 15 months (2-32). Incomplete ablation rate was 2.5% (1/40), local recurrence rate 10% (4/40). Three patients (12%) had minor complications. Overall disease progression was 73.9% (17/23), median disease-free survival 7 months (0-26) and overall survival 18 months (2-39). SIMWA is feasible, safe and minimally invasive for NCRLM in selected patients. While it might offer an alternative to resection or palliative strategies, the oncological benefit needs to be evaluated in a larger patient cohort.

Surgical management of metastatic gastric cancer: moving beyond the guidelines

Despite decreasing incidence, gastric cancer remains a major health problem worldwide and is associated with poor survival. The poor survival is mainly attributed to delayed presentation which may cause local or systemic metastases. The standard of care for patients with metastatic gastric cancer (MGC) is palliative chemotherapy with best supportive care. Although the survival has improved owing to advances in chemotherapeutic agents, it is still unsatisfactory, and some perspective changes are needed in the management of MGC to improve the outcomes. Therefore, various alternative treatment strategies for MGC have formed the most important research topics. Liver-directed treatment (LDT) options such as liver resection, radiofrequency ablation (RFA), microwave ablation (MWA), and hepatic artery infusion chemotherapy (HAIC) have been studied in the management of liver metastasis from gastric cancer (LMGC). Intraperitoneal chemotherapy (IPC) in addition to cytoreductive surgery (CRS) aiming to remove all macroscopic tumor focus resulting from peritoneal dissemination is the treatment option for peritoneal metastasis, while para-aortic lymph node dissection is the treatment option for para-aortic lymph node metastasis which is considered to be M1 disease. Conversion surgery is a novel concept aiming at R0 resection for originally unresectable or marginally resectable tumors after a remarkably good response to the chemotherapy. Large amounts of data in the literature have demonstrated the benefits of individualized approaches such as the combination of systemic and local treatment options in selected patient groups. In this review, we aimed to explore the current and future treatment options by reviewing the literature on this controversial topic.

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

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

Microwave ablation compared with hepatic resection for the treatment of hepatocellular carcinoma and liver metastases: a systematic review and meta-analysis

Background

Hepatic resection (HR) is the gold standard liver cancer treatment, but few patients are eligible due to comorbidities or tumor location. Microwave ablation (MWA) is an important complementary liver cancer treatment to HR. This systematic review compared MWA with HR for liver cancer treatment.

Methods

A systematic search of MEDLINE, EMBASE, and CENTRAL was conducted for randomized and observational studies published from 2006 onwards. The primary outcome was local tumor recurrence (LTR), and a random effects model was used for meta-analyses.

Results

Of the 1845 studies identified, 1 randomized and 15 observational studies met the inclusion criteria. LTR was significantly increased with MWA versus HR (risk ratio (RR) = 2.49; P = 0.016). In secondary measures, HR provided significantly higher 3- and 5-year overall survival (RR = 0.94; P = 0.03 and RR = 0.88; P = 0.01, respectively) and 3-year disease-free survival (RR = 0.78; P = 0.009). MWA exhibited significantly shorter length of stay (weighted mean difference (WMD) = − 6.16 days; P < 0.001) and operative time (WMD = − 58.69 min; P < 0.001), less intraoperative blood loss (WMD = − 189.09 mL; P = 0.006), and fewer complications than HR (RR = 0.31; P < 0.001). When MWA was combined with HR and compared with either modality alone, complications and blood loss were significantly lower with the combination treatment; however, there were no differences in other outcomes. Subgroup and sensitivity analyses were generally aligned with the main results.

Conclusions

MWA can be an effective and safe alternative to HR in patients/tumors that are not amenable to resection. More randomized and economic studies should be performed that compare the two treatments, especially to determine the target population that benefits most from MWA.

Electronic supplementary material

The online version of this article (10.1186/s12957-019-1632-6) contains supplementary material, which is available to authorized users.

Aggressive Graphic/Surgical R0 Resection and Jejunal Interposition with Preservation of Mesojejunal Autonomic Nerves in Patients with Stage IV Esophagogastric Junction Adenocarcinoma: A Report of 3 Cases

BACKGROUND Three patients with stage IV esophagogastric junction cancer (EGJC) underwent extended resection to achieve a graphic/surgical R0 status (no visible remnant of viable tumor in imaging/surgical findings) and adjuvant chemotherapy from the early postoperative period. We also introduced use of our digestive reconstruction technique in these patients. CASE REPORT We used jejunal interposition for digestive reconstruction, which involved end-to-end jejunojejunostomy with a biofragmentable anastomosis ring. The mesojejunal autonomic nerves of the lifted jejunum were preserved. The first adenocarcinoma involved the perilesional lymph nodes (LNs). Graphic/surgical R0 resection was completed by para-aortic LN dissection. The diagnosis (Japanese Classification of Gastric Carcinoma) was stage IV [pM1(LYM)]. Adjuvant chemotherapy began on postoperative day (POD) 11. The second adenocarcinoma was accompanied by a solitary lung metastasis. Intraoperative cytology of ascitic fluid was positive, and cisplatin was intraperitoneally administered. Adjuvant chemotherapy began on POD 10. The solitary lung metastasis was then resected, and graphic/surgical R0 resection was achieved. The diagnosis was stage IV [pM1(PUL) and CY1]. The third adenocarcinoma was accompanied by multiple liver metastases and metastatic regional LNs. The diagnosis was stage IV [H1]. Systemic chemotherapy was repeated. Only a solitary liver metastasis remained and was treated by radiofrequency ablation. Conversion surgery was conducted, achieving graphic/surgical R0 resection. Systemic chemotherapy was continued from POD 10. CONCLUSIONS For patients with stage IV EGJC, extended resection to achieve a graphic/surgical R0 status is still controversial, and systemic chemotherapy is important. The results of the present study suggest that our physiological reconstruction technique does not affect the efficacy of other therapies, such as adjuvant chemotherapy.

Regional therapies for the treatment of primary and metastatic hepatic tumors: A disease-based review of techniques and critical appraisal of current evidence

The practice of hepatic surgery has become increasingly complex as additional therapeutic options emerge to treat both primary and metastatic tumors of the liver. Liver-directed therapy options include selective internal radiation therapy (SIRT), stereotactic body radiation therapy, chemoembolization, bland embolization, hepatic artery infusion chemotherapy (HAIC), and ablative techniques such as microwave or radiofrequency ablation. Hepatocellular carcinoma has been treated with many of these therapies for palliation of symptoms, definitive treatment, and as a bridge to transplantation. Intrahepatic cholangiocarcinoma, particularly patients with unresectable disease, have demonstrated clinical responses to both SIRT as well as HAIC. Colorectal liver metastases have been treated with all of these techniques with varying degrees of success depending on the clinical scenario. A detailed understanding of these technologies and the evidence supporting their use is essential for the modern hepatic surgeon to properly sequence therapies and provide salvage options when first-line treatment has failed. This review describes these techniques and their appropriate usage based on the disease of interest and the respective evidence currently available.