Comparison of hepatic recurrences after resection or intraoperative radiofrequency ablation indicated by size and topographical characteristics of the metastases. Eur J Surg Oncol. 2008;34:185-190. [PMID: 17998155 DOI: 10.1016/j.ejso.2007.09.028]

Oncologic Outcomes after Percutaneous Ablation for Colorectal Liver Metastases: An Updated Comprehensive Review

Colorectal cancer is a major cause of cancer-related mortality, with liver metastases occurring in over a third of patients, and is correlated with poor prognosis. Despite surgical resection being the primary treatment option, only about 20% of patients qualify for surgery. Current guidelines recommend thermal ablation either alone or combined with surgery to treat limited hepatic metastases, provided that all visible disease can be effectively eradicated. Several ablation modalities, including radiofrequency ablation, microwave ablation, cryoablation, irreversible electroporation and histotripsy, are part of the percutaneous ablation armamentarium. Thermal ablation, including radiofrequency, microwave ablation and cryoablation, can offer local tumor control rates comparable to limited resection for selected tumors that can be ablated with margins. This review aims to encapsulate the current clinical evidence regarding the efficacy and oncologic outcomes after percutaneous ablation for the treatment of colorectal liver metastatic disease.

Local Treatments in the Unresectable Patient with Colorectal Cancer Metastasis: A Review from the Point of View of the Medical Oncologist

For patients with isolated liver metastases from colorectal cancer who are not candidates for potentially curative resections, non-surgical local treatments may be useful. Non-surgical local treatments are classified according to how the treatment is administered. Local treatments are applied directly on hepatic parenchyma, such as radiofrequency, microwave hyperthermia and cryotherapy. Locoregional therapies are delivered through the hepatic artery, such as chemoinfusion, chemoembolization or selective internal radiation with Yttrium 90 radioembolization. The purpose of this review is to describe the different interventional therapies that are available for these patients in routine clinical practice, the most important clinical trials that have tried to demonstrate the effectiveness of each therapy and recommendations from principal medical oncologic societies.

A literature-based treatment algorithm for low-grade neuroendocrine liver metastases

BACKGROUND

The optimal timing of treatment of liver metastases from low-grade neuroendocrine tumors (LG-NELM) varies significantly due to numerous treatment modalities and the literature supporting various treatment(s). This study sought to create and validate a literature-based treatment algorithm for LG-NELM.

METHODS

A treatment algorithm to maximize overall survival (OS) was designed using peer-reviewed articles evaluating treatment of LG-NELM. This algorithm was retrospectively applied to patients treated for LG-NELM at our institution. Deviation was determined based on whether or not a patient received treatment consistent with that recommended by the algorithm. Patients who did and did not deviate from the algorithm were compared with respect to OS and number of treatments.

RESULTS

Applying our algorithm to a 149-patient cohort, 57 (38%) deviated from recommended treatment. Deviation occurred in the form of alternative (28, 49%) versus additional procedures (29, 51%). Algorithm deviators underwent significantly more procedures than non-deviators (median 1 vs. 2, p < 0.001). Cox model indicated no difference in OS associated with algorithm deviation (HR 1.19, p = 0.58) when controlling for age and tumor characteristics.

CONCLUSION

This literature-based algorithm helps standardize treatment protocols in patients with LG-NELM and can reduce cost and risk by minimizing unnecessary procedures. Prospective implementation and validation is required.

Clinical practice guidelines for the management of liver metastases from extrahepatic primary cancers 2021

BACKGROUND

Hepatectomy is standard treatment for colorectal liver metastases; however, it is unclear whether liver metastases from other primary cancers should be resected or not. The Japanese Society of Hepato-Biliary-Pancreatic Surgery therefore created clinical practice guidelines for the management of metastatic liver tumors.

METHODS

Eight primary diseases were selected based on the number of hepatectomies performed for each malignancy per year. Clinical questions were structured in the population, intervention, comparison, and outcomes (PICO) format. Systematic reviews were performed, and the strength of recommendations and the level of quality of evidence for each clinical question were discussed and determined. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The eight primary sites were grouped into five categories based on suggested indications for hepatectomy and consensus of the guidelines committee. Fourteen clinical questions were devised, covering five topics: (1) diagnosis, (2) operative treatment, (3) ablation therapy, (4) the eight primary diseases, and (5) systemic therapies. The grade of recommendation was strong for one clinical question and weak for the other 13 clinical questions. The quality of the evidence was moderate for two questions, low for 10, and very low for two. A flowchart was made to summarize the outcomes of the guidelines for the indications of hepatectomy and systemic therapy.

CONCLUSIONS

These guidelines were developed to provide useful information based on evidence in the published literature for the clinical management of liver metastases, and they could be helpful for conducting future clinical trials to provide higher-quality evidence.

Impact of concomitant ablation on the perioperative outcomes of patients with colorectal liver metastases undergoing hepatectomy: a propensity score matched nationwide analysis

BACKGROUND

Intraoperative ablation (IA) is often performed at the time of liver resection (LR) for colorectal liver metastases (CRLMs) but its impact on postoperative outcomes remains poorly understood.

METHODS

The ACS-NSQIP targeted hepatectomy database was used to identify patients who underwent LR vs LR + IA for CRLMs during 2014-2016. Perioperative outcomes were compared following propensity score match based on age, receipt of neoadjuvant therapy, operative approach, liver resection type, tumor diameter and number of metastases.

RESULTS

Among 1,384 patients, 692 (50%) underwent LR alone and 692 (50%) underwent LR + IA. After propensity score matching, overall morbidity (22% vs 13%, P < 0.0001) was increased among patients undergoing LR alone compared to LR + IA, whereas mortality did not differ (1.1% vs 0.8%, P=0.5911). On multivariable analysis, ASA class ≥3 (OR: 1.5, 95% CI: 1.06-2.3), preoperative biliary stent (OR: 3.5, 95% CI: 0.9-13.01), biliary reconstruction (OR: 5.02, 95% CI: 1.3-18.6), operative time > 245 minutes (OR: 1.8, 95% CI:1.3-2.4) and IA (OR:0.5, 95% CI:0.3-0.7) were associated with overall morbidity.

CONCLUSIONS

In this propensity matched nationwide analysis of patients undergoing LR for CRLM, the use of concomitant IA was associated with decreased postoperative morbidity compared to LR alone. These findings suggest that IA combined with LR is a safe approach that may expand the number of patients who are candidates for curative-intent surgical strategies.

Radiofrequency ablation with systemic chemotherapy in the treatment of colorectal cancer liver metastasis: a 10-year single-center study

Objective

To retrospectively evaluate the long-term efficacy and safety of radiofrequency ablation (RFA) with systemic chemotherapy (CT) in treatment of solitary liver metastasis after surgery for colorectal cancer (CRC).

Methods

This single-center study was conducted at the Hunan Provincial Cancer Hospital from June 2006 to December 2015 with median follow-up time of 26 months. Percutaneous ultrasound-guided RFA was carried out on eligible patients with solitary liver metastasis after surgery for CRC. After a week, ablation status was confirmed by MRI. Post MRI, all patients received systemic CT with or without molecular-targeted therapy. Survival rate was evaluated and survival curve was constructed with Kaplan-Meier analysis. Log-rank test and Cox regression model were used for univariate and multivariate analysis, respectively, to determine the independent prognostic factors for survival rate.

Results

A total of 109 eligible patients (mean age, 53.84±11.71; mean tumor mass diameter, 3.4+2.01 cm) were enrolled in this 10-year study. After RFA, 95 patients achieved complete ablation, and 14 patients achieved partial ablation, with median ablation time of 26 minutes (range: 12-120 minutes). The median survival time required for achieving complete and partial ablation was 56.0 and 19.0 months, respectively (P<.01). After RFA and adjuvant systemic CT, the 1-, 3-, and 5-year survival rates were 92.3%, 50.7%, and 41.6%, respectively, with the median (mean) survival time of 39.0 (56.5) months. Age was the only significant independent prognostic factor with better survival rate observed in patients aged ≥50 years than those aged <50 years (P<0.05). The incidence of complications was minimal (1.8%) with only two cases: one biliary fistula and one liver hemorrhage.

Conclusion

RFA combination with systemic CT was safe; it showed long-term efficacy in patients with solitary liver metastasis after surgery for CRC and can be a preferred treatment.

The Role of Liver-Directed Therapy in Metastatic Colorectal Cancer

Purpose of Review

Colorectal cancer liver metastasis is a major clinical problem, and surgical resection is the only potentially curative treatment. We seek to discuss various liver-directed therapy modalities and explore their roles in the evolving realm of treatment strategies for metastatic colorectal cancer.

Recent Findings

Clinical outcomes for patients with colorectal cancer liver metastases have improved as more patients undergo potentially curative resection and as the armamentarium of systemic treatment and liver-directed therapies continues to expand. Liver-directed therapies have been developed as adjuncts to improve resectability, employed in the adjuvant setting to potentially reduce local recurrence rates, and utilized in the palliative setting with the aim to improve overall survival.

Summary

Ongoing research is expected to validate the role of these evolving therapeutic options, and determine how best to sequence and when to apply these therapies.

Distant Liver Metastases as a Major Factor Influencing Survival in Patients with Colorectal Cancer

AIM

To assess the effect of the factor 'hepatic metastatic disease' on long-term outcomes in patients with colorectal cancer.

MATERIALS AND METHODS

We analysed retrospectively 200 randomly selected patients. Forty-two of them were excluded from the study for different reasons so the study contingent was 158 patients over a period of 23 years. All were diagnosed and treated in the Lozenetz University Hospital, in the Department of General Surgery. 125 of the patients were diagnosed with colorectal cancer without distant metastases and 33 of the patients had liver metastases as a result of colorectal carcinoma. The statistical analysis was performed using SPSS 19 IMB, with a level of significance of P < 0.05 at which the null hypothesis is rejected. We also used descriptive analysis, Kaplan-Meier estimator, Log-Rank Test and Life-Table statistics models.

RESULTS

The median survival for patients without metastases was 160 months, and the median was 102 months. The median survival for patients with liver metastases was 28 months and the median was 21 months. One-year survival for patients without metastases was 92% versus 69% in patients with liver metastases.

CONCLUSION

Average, annual and median survivals are influenced statistically significantly by the presence of liver metastases compared to overall survival and that of patients without metastatic colorectal cancer. Liver metastatic disease is a proven factor affecting long-term prognosis and survival in patients with colorectal cancer.

The role of intraoperative ultrasonography in the diagnosis and management of focal hepatic lesions

Intraoperative ultrasonography (IOUS) has been widely utilized in hepatic surgery both as a diagnostic technique and in the course of treatment. Since IOUS involves direct-contact imaging of the target organ, it can provide high spatial resolution without interference from the surrounding structures. Therefore, IOUS may improve the detection, characterization, localization, and local staging of hepatic tumors. IOUS is also a real-time imaging modality capable of providing interactive information and valuable guidance in a range of procedures. Recently, contrast-enhanced IOUS, IOUS elastography, and IOUS-guided hepatic surgery have attracted increasing interest and are expected to lead to the broader implementation of IOUS. Herein, we review the various applications of IOUS in the diagnosis and management of focal hepatic lesions.

Minimally invasive local therapies for liver cancer

Primary and metastatic liver tumors are an increasing global health problem, with hepatocellular carcinoma (HCC) now being the third leading cause of cancer-related mortality worldwide. Systemic treatment options for HCC remain limited, with Sorafenib as the only prospectively validated agent shown to increase overall survival. Surgical resection and/or transplantation, locally ablative therapies and regional or locoregional therapies have filled the gap in liver tumor treatments, providing improved survival outcomes for both primary and metastatic tumors. Minimally invasive local therapies have an increasing role in the treatment of both primary and metastatic liver tumors. For patients with low volume disease, these therapies have now been established into consensus practice guidelines. This review highlights technical aspects and outcomes of commonly utilized, minimally invasive local therapies including laparoscopic liver resection (LLR), radiofrequency ablation (RFA), microwave ablation (MWA), high-intensity focused ultrasound (HIFU), irreversible electroporation (IRE), and stereotactic body radiation therapy (SBRT). In addition, the role of combination treatment strategies utilizing these minimally invasive techniques is reviewed.

When should a liver resection be performed in patients with liver metastases from neuroendocrine tumours? A systematic review with practice recommendations

AIM

To determine the benefits and risks of hepatic resection versus non-resectional liver-directed treatments in patients with potentially resectable neuroendocrine liver metastases.

METHODS

A systematic review identified 1594 reports which alluded to a possible liver resection for neuroendocrine tumour metastases, of which 38 reports (all retrospective), comprising 3425 patients, were relevant.

RESULTS

Thirty studies reported resection alone, and 16 studies reported overall survival (OS). Only two studies addressed quality-of-life (QoL) issues. Five-year overall survival was reported at 41-100%, whereas 5-year progression-free survival (PFS) was 5-54%. We identified no robust evidence that a liver resection was superior to any other liver-directed therapies in improving OS or PFS. There was no evidence to support the use of a R2 resection (debulking), with or without tumour ablation, to improve either OS or QoL. There was little evidence to guide sequencing of surgery for patients presenting in Stage IV with resectable disease, and none to support a resection of asymptomatic primary tumours in the presence of non-resectable liver metastases.

CONCLUSION

Low-level recommendations are offered to assist in the management of patients with neuroendocrine liver metastases, along with recommendations for future studies.

Combined ablation and resection (CARe) as an effective parenchymal sparing treatment for extensive colorectal liver metastases

BACKGROUND

Combined intra-operative ablation and resection (CARe) is proposed to treat extensive colorectal liver metastases (CLM). This multicenter study was conducted to evaluate overall survival (OS), local recurrence-free survival (LRFS), hepatic recurrence-free survival (HRFS) and progression-free survival (PFS), to identify factors associated with survival, and to report complications.

MATERIALS AND METHODS

Four centers combined retropectively their clinical experiences regarding CLM treated by CARe. CLM characteristics, pre- and post-operative chemotherapy regimens, surgical procedures, complications and survivals were analyzed.

RESULTS

Of the 288 patients who received CARe, 210 (73%) had synchronous and 255 (88%) had bilateral CLM. Twenty-two patients (8%) had extrahepatic disease. Median follow-up was 3.17 years (95%CI 2.83-4.08). Median OS was 3.33 years (95%CI 3.08-4.17) and 5-year OS was 37% (95%CI 29-45). One- and 5-year LRFS from ablated lesions were 87.9% (95%CI 83.3-91.2) and 78.0% (95%CI 71-83), respectively. Median HRFS and PFS were 14 months (95%CI 11-18) and 9 months (95%CI 8-11), respectively. One hundred patients experienced complications: 29 grade I, 68 grade II-III-IV, and three deaths. In the multivariate models adjusted for center, the occurrence of complications was confirmed as a major independent factor associated with 3-year OS (HR 1.80; P = 0.008). Five-year OS was 25.6% (95%CI 14.9-37.6) for patients with complications and 45% (95%CI 33.3-53.4) for patients without.

CONCLUSIONS

Recent strategies facing advanced CLM include non-anatomic resections, portal-induced hypertrophy of the future remnant liver and aggressive medical preoperative treatments. CARe has the qualities of an approach that allows effective tumor clearance while maintaining good tolerance for the patient.

Patterns of complications following intraoperative radiofrequency ablation for liver metastases

BACKGROUND

Intraoperative radiofrequency ablation (IRFA) is added to surgery to obtain hepatic clearance of liver metastases. Complications occurring in IRFA should differ from those associated with wedge or anatomic liver resection.

METHODS

Patients with liver metastases treated with IRFA from 2000 to 2010 were retrospectively analysed. Postoperative outcomes are reported according to the Clavien-Dindo system of classification.

RESULTS

A total of 151 patients underwent 173 procedures for 430 metastases. Of these, 97 procedures involved IRFA plus liver resection and 76 involved IRFA only. The median number of lesions treated by IRFA was two (range: 1-11). A total of 123 (71.1%) procedures were carried out in patients who had received preoperative chemotherapy. The mortality rate was 1.2%. Thirty (39.5%) IRFA-only patients and 45 (46.4%) IRFA-plus-resection patients presented complications. Immediate complications (n = 4) were associated with IRFA plus resection. American Society of Anesthesiologists (ASA) class, previous abdominal surgery or hepatic resection, body mass index, number of IRFA procedures, portal pedicle clamping, total vascular exclusion and preoperative chemotherapy were not associated with a greater number of complications of Grade III or higher severity. Length of surgery >4 h [odds ratio (OR) 2.67, 95% confidence interval (CI) 1.1-6.3; P < 0.05] and an associated contaminating procedure (OR 3.72, 95% CI 1.53-9.06; P < 0.005) led to a greater frequency of complications of Grade III or higher.

CONCLUSIONS

Mortality and morbidity after IRFA, with or without resection, are low. Nevertheless, long interventions and concurrent bowel operations increase the risk for septic complications.

Liver-directed therapies in metastatic colorectal cancer

Colorectal cancer (CRC) is a major health concern in the United States (US) with over 140,000 new cases diagnosed in 2012. The most common site for CRC metastases is the liver. Hepatic resection is the treatment of choice for colorectal liver metastases (CLM), with a 5-year survival rate ranging from 35% to 58%. Unfortunately, only about 20% of patients are eligible for resection. There are a number of options for extending resection to more advanced patients including systemic chemotherapy, portal vein embolization (PVE), two stage hepatectomy, ablation and hepatic artery infusion (HAI). There are few phase III trials comparing these treatment modalities, and choosing the right treatment is patient dependent. Treating hepatic metastases requires a multidisciplinary approach and knowledge of all treatment options as there continues to be advances in management of CLM. If a patient can undergo a treatment modality in order to increase their potential for future resection this should be the primary goal. If the patient is still deemed unresectable then treatments that lengthen disease-free and overall-survival should be pursued. These include chemotherapy, ablation, HAI, chemoembolization, radioembolization (RE) and stereotactic radiotherapy.

Thermal ablation of liver metastases from colorectal cancer: radiofrequency, microwave and laser ablation therapies

Surgery is currently considered the treatment of choice for patients with colorectal cancer liver metastases (CRLM) when resectable. The majority of these patients can also benefit from systemic chemotherapy. Recently, local or regional therapies such as thermal ablations have been used with acceptable outcomes. We searched the medical literature to identify studies and reviews relevant to radiofrequency (RF) ablation, microwave (MW) ablation and laser-induced thermotherapy (LITT) in terms of local progression, survival indexes and major complications in patients with CRLM. Reviewed literature showed a local progression rate between 2.8 and 29.7 % of RF-ablated liver lesions at 12-49 months follow-up, 2.7-12.5 % of MW ablated lesions at 5-19 months follow-up and 5.2 % of lesions treated with LITT at 6-month follow-up. Major complications were observed in 4-33 % of patients treated with RF ablation, 0-19 % of patients treated with MW ablation and 0.1-3.5 % of lesions treated with LITT. Although not significantly different, the mean of 1-, 3- and 5-year survival rates for RF-, MW- and laser ablated lesions was (92.6, 44.7, 31.1 %), (79, 38.6, 21 %) and (94.2, 61.5, 29.2 %), respectively. The median survival in these methods was 33.2, 29.5 and 33.7 months, respectively. Thermal ablation may be an appropriate alternative in patients with CRLM who have inoperable liver lesions or have operable lesions as an adjunct to resection. However, further competitive evaluation should clarify the efficacy and priority of these therapies in patients with colorectal cancer liver metastases.

Clinical outcome of ultrasound-guided percutaneous microwave ablation on colorectal liver metastases

The present study aimed to assess the feasibility, safety and efficiency of ultrasound-guided percutaneous microwave ablation (MWA) on liver metastases from colon or rectal cancer. Patients who received MWA therapy for liver metastases from colon or rectal cancer between June 2009 and May 2012 were enrolled in the study. Follow-up data was collected from the patients in order to statistically analyze the adverse effects, concurrent disease and survival status. Of the total 115 patients, 62 presented with colon cancer and 53 with rectal cancer. A total of 78 patients were male and 37 were female. The patient age ranged between 30 and 86 years [mean ± standard deviation (SD), 59.46±11.79 years]. The number of overall ablation lesions was 165, and the diameter of the lesions ranged between 1.3 and 5.0 cm (mean ± SD, 3.10±1.05 cm). Subsequent to treatment, the mean (± SD) hospitalization time was 4.69±2.08 days (range, 2-10 days). The median follow-up time was 28 months (range, 12-48 months) and 5 patients were lost to follow-up. The pain grade was recorded between the 4th and 6th degree following treatment in 23 patients. The body temperatures of 35 patients reached >38°C, with the longest time at this temperature recorded as 5 days. Following treatment, 5 patients presented with pleural effusion and required thoracocentesis and drainage. Following ablation, the rate of local progression was 11.82%. The recurrence rates were 27.8, 48.4 and 59.3% and the cumulative survival rates were 98.1, 87.1 and 78.7% in years 1, 2 and 3 post-treatment, respectively. A total of 14 patients succumbed. No significant differences were observed in the liver metastases of colorectal cancer with regard to gender, age, number of lesions, lesion size and pathological differentiation (P>0.05). Also, no significant difference was observed in the recurrence or cumulative survival rates for years 1, 2 and 3 years post-treatment (P>0.05). In conclusion, ultrasound-guided percutaneous MWA is a safe and competent way to treat inoperable colorectal liver metastases.

Locally ablative therapies for primary and metastatic liver cancer

Locally ablative therapies have an increasing role in the effective multidisciplinary approach towards the treatment of both primary and metastatic liver tumors. In patients who are not considered surgical candidates and have low volume disease, these therapies have now become established into consensus practice guidelines. A large range of therapeutic options exist including percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation, percutaneous laser ablation (PLA), irreversible electroporation (IRE), stereotactic body radiation therapy (SBRT) and high intensity focused ultrasound (HIFU); each having benefits and drawbacks. The greatest body of evidence supporting clinical utility in the liver currently exists for RFA, with PEI having fallen out of favor. MWA, IRE, SBRT and HIFU are relatively nascent technologies, and outcomes data supporting their use is promising. Future directions of ablative therapies include tandem approaches to improve efficacy in the treatment of liver tumors.

Limits of colorectal liver metastases resectability: how and why to overcome them? For progress in cancer research

Offering surgery is to date the best case scenario for patients with colorectal liver metastases (CRLM). Few oncological topics have progressed as much as the treatment of CRLM. New surgical techniques, conversion therapies, and imaging allow us to pursue the ultimate limit for surgery of CLM before compromising patient benefits. Pushing the limits of surgery involves pushing the limits of conversion therapies too, increasingly taking risks in the surgical process. Finally, toxicities add up and the patient benefit could disappear. The apparent paradox of efficiency and toxicity might be addressed by separating the two treatment targets: (1) The metastatic burden for which a clear escalation in medical and surgical aggressiveness is still required. (2) The healthy parenchyma which should be preserved as much as possible and for which a clear de-escalation is anticipated. A new strategy exists that integrates both fundamental endpoints in the battle against CLM.

Interventional oncologic approaches to liver metastases

Metastatic liver disease is the most common cause of death in cancer patients. Complete surgical resection is currently considered the only curative treatment, with only about 25% of patients being amenable to surgery. Therefore, a variety of interventional oncologic techniques have been developed for treating secondary liver malignancies. The aim of these therapies is either to allow patients with unresectable tumors to become surgical candidates, provide curative treatment options in nonsurgical candidates, or improve survival in a palliative or even curative approach. Among these interventional therapies are transcatheter therapies such as portal vein embolization, hepatic artery infusion chemotherapy, transarterial chemoembolization, and radioembolization, as well as interstitial techniques, particularly radiofrequency ablation as the most commonly applied technique. The rationale, application and clinical results of each of these techniques are reviewed on the basis of the current literature. Future prospects such as gene therapy and immunotherapy are introduced.

Radiofrequency ablation versus resection for colorectal cancer liver metastases: a meta-analysis

BACKGROUND

No randomized controlled trial (RCT) has yet been performed to provide the evidence to clarify the therapeutic debate on liver resection (LR) and radiofrequency ablation (RFA) in treating colorectal liver metastases (CLM). The meta-analysis was performed to summarize the evidence mostly from retrospective clinical trials and to investigate the effect of LR and RFA.

METHODOLOGY/PRINCIPAL FINDINGS

Systematic literature search of clinical studies was carried out to compare RFA and LR for CLM in Pubmed, Embase and the Cochrane Library Central databases. The meta-analysis was performed using risk ratio (RR) and random effect model, in which 95% confidence intervals (95% CI) for RR were calculated. Primary outcomes were the overall survival (OS) and disease-free survival (DFS) at 3 and 5 years plus mortality and morbidity. 1 prospective study and 12 retrospective studies were finally eligible for meta-analysis. LR was significantly superior to RFA in 3 -year OS (RR 1.377, 95% CI: 1.246-1.522); 5-year OS (RR: 1.474, 95%CI: 1.284-1.692); 3-year DFS (RR 1.735, 95% CI: 1.483-2.029) and 5-year DFS (RR 2.227, 95% CI: 1.823-2.720). The postoperative morbidity was higher in LR (RR: 2.495, 95% CI: 1.881-3.308), but no significant difference was found in mortality between LR and RFA. The data from the 3 subgroups (tumor<3 cm; solitary tumor; open surgery or laparoscopic approach) showed significantly better OS and DFS in patients who received surgical resection.

CONCLUSIONS/SIGNIFICANCES

Although multiple confounders exist in the clinical trials especially the bias in patient selection, LR was significantly superior to RFA in the treatment of CLM, even when conditions limited to tumor<3 cm, solitary tumor and open surgery or laparoscopic (lap) approach. Therefore, caution should be taken when treating CLM with RFA before more supportive evidences for RFA from RCTs are obtained.

Radiofrequency ablation in the treatment of liver metastases from colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the most common malignant tumour and the third leading cause of cancer deaths in USA. For advanced CRC, the liver is the first site of metastatic disease; approximately 50 % of patients with CRC will develop liver metastases either synchronously or metachronously within 2 years after primary diagnosis. Hepatic resection (HR) is the only curative option, but only 15-20% of patients with liver metastases from CRC (CRLMs) are suitable for surgical standard treatment. In patients with unresectable CRLMs downsizing chemotherapy can improve resectability (16%). Modern systemic chemotherapy represents the only significant treatment for unresectable CRLMs. However several loco-regional treatments have been developed: hepatic arterial infusion (HAI), cryosurgical ablation (CSA), radiofrequency ablation (RFA), microwave ablation and selective internal radion treatment (SIRT). During the past decade RFA has superseded other ablative therapies, due to its low morbidity, mortality, safety and patient acceptability.

OBJECTIVES

The objective of this study was to systematically review the role of radiofrequency ablation (RFA) in the treatment of CRLMs.

SEARCH METHODS

We performed electronic searches in the following databases:CENTRAL, MEDLINE and EMBASE. Current trials were identified through the Internet using the Clinical-Trials.gov site (to January 2, 2012) and ASCO Proceedings. The reference lists of identified trials were reviewed for additional studies.

SELECTION CRITERIA

Randomized clinical trials (RCTs), quasi-randomised or controlled clinical trials (CCTs) comparing RFA to any other therapy for CRLMs were included. Observational study designs including comparative cohort studies comparing RFA to another intervention, single arm cohort studies or case control studies have been included if they have: prospectively collected data, ten or more patients; and have a mean or median follow-up time of 24 months. Patients with CRLMs who have no contraindications for RFA. Patients with unresectable extra-hepatic disease were also included.Trials have been considered regardless of language of origin.

DATA COLLECTION AND ANALYSIS

A total of 1144 records were identified through the above electronic searching. We included 18 studies: 10 observational studies, 7 Clinical Controlled Trials (CCTs) and an additional 1 Randomized Clinical Trial (RCT) (abstract) identified by hand searching in the 2010 ASCO Annual Meeting. The most appropriate way of summarizing time-to-event data is to use methods of survival analysis and express the intervention effect as a hazard ratio. In the included studies these outcome are mostly reported as dichotomous data so we should have asked authors research data for each participant and perform Individual Patient Data (IPD) meta-analysis. Given the study design and low quality of included studies we decided to give up and not to summarize these data.

MAIN RESULTS

Seventeen studies were not randomised and this increases the potential for selection bias. In addition, there was imbalance in the baseline characteristics of the participants included in all studies. All studies were classified as having a elevate risk of bias. The assessment of methodological quality of all non-randomized studies included in meta-analysis performed by the STROBE checklist has allowed us to identify several methodological limits in most of the analysed studies. At present, the information from the single RCT included (Ruers 2010) comes from an abstract of 2010 ASCO Annual Meeting where the allocation concealment was not reported; however in original protocol allocation concealment was adequately reported (EORTC 40004 protocol). The heterogeneity regarding interventions, comparisons and outcomes rendered the data not suitable.

AUTHORS' CONCLUSIONS

This systematic review gathers information from several controlled clinical trials and observational studies which are vulnerable to different types of bias. The imbalance between characteristics of patients in the allocated groups appears to be the main concern. Only one randomised clinical trial (published as an abstract), comparing 60 patients receiving RFA plus CT versus 59 patients receiving CT alone, was identified. This study showed that PFS was significantly higher in the group that received RFA. However, it was not able to provide information on overall survival. In conclusion, evidence from the included studies are insufficient to recommend RFA for a radical oncological treatment of CRLMs.

Does Radiofrequency Ablation Add to Chemotherapy for Unresectable Liver Metastases?

In patients with unresectable colorectal liver metastases (CRLM), radiofrequency ablation (RFA) might be a good alternative, whenever possible. In contrast to systemic therapy, the aim of RFA is to achieve complete local tumor control in an attempt to provide long-term survival. In this article we discuss the available evidence regarding the treatment of patients with unresectable CRLM, focusing on RFA in conjunction with modern systemic therapies. We observed that the available evidence in the existing literature is limited, and often consists of level 2 and 3 evidence, thereby hampering any firm conclusions. Nonetheless, RFA seems superior to chemotherapy alone in patients with liver-only disease amenable for RFA. However, the combination of RFA and chemotherapy has been demonstrated to be feasible and safe, lending support to the concept of RFA followed by chemotherapy, in order to reduce local recurrence rates and prolong survival.

Unresectable colorectal cancer liver metastases treated by intraoperative radiofrequency ablation with or without resection19

Background

Despite neoadjuvant chemotherapy, few patients with colorectal cancer liver metastases (CRLM) are eligible for liver resection. The aim of the present study was to investigate the efficacy of intraoperative radiofrequency ablation (IRFA) in the treatment of unresectable CRLM.

Methods

Patients with unresectable metastases confined to the liver were eligible for this prospective, multicentre phase II study conducted between 2003 and 2008. They received IRFA treatment either with or without parenchymal resection, and underwent clinical and pathological examinations. The primary endpoint was complete hepatic response at 3 months. Overall, event-free and local progression-free survival, morbidity and quality of life were also examined.

Results

Fifty-two patients were included, all of whom received neoadjuvant chemotherapy. They had a median of 5 (range 1–13) metastases, mostly bilateral or recurrent. A complete hepatic response was observed in 39 patients (75 (95 per cent confidence interval (c.i.) 61 to 86) per cent). Of ten patients with hepatic recurrence at 3 months, two relapses were at the site of ablation. Median follow-up was 2·9 (95 per cent c.i. 2·5 to 3·6) years. The 1-year local progression-free survival rate was 46 (95 per cent c.i. 32 to 59) per cent, the 3-year event-free survival rate was 10 (95 per cent c.i. 4 to 21) per cent and the 5-year overall survival rate was 43 (95 per cent c.i. 21 to 64) per cent. Twenty patients had postoperative complications, including one death. Quality of life increased over time for patients without disease progression.

Conclusion

IRFA, either with or without resection, is a promising treatment option for patients with unresectable CRLM. Registration number: NTC00210106 (http://www.clinicaltrials.gov).

Radiofrequency ablation vs hepatic resection for solitary colorectal liver metastasis: A meta-analysis

AIM: To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).

METHODS: A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM. Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.

RESULTS: Seven nonrandomized controlled trials studies were included in this analysis. These studies included a total of 847 patients: 273 treated with RFA and 574 treated with HR. The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR: 0.41, 95% CI: 0.22-0.90, P = 0.008). RFA had a higher rate of local intrahepatic recurrence compared to HR (OR: 4.89, 95% CI: 1.73-13.87, P = 0.003). No differences were found between the two groups with respect to postoperative morbidity and mortality.

CONCLUSION: HR was superior to RFA in the treatment of patients with solitary CLM. However, the findings have to be carefully interpreted due to the lower level of evidence.

Ablative therapies for colorectal liver metastases: a systematic review

AIM

The standard treatment for colorectal liver metastases (CRLM) is surgical resection. Only 20-30% of patients are deemed suitable for surgery. Recently, much attention has focused on ablative therapies either to treat unresectable CRLM or to extend the margins of resectability. This review aims to assess the long-term outcome and complication rates of various ablative therapies used in the management of CRLM.

METHOD

A literature search was performed of electronic databases including Medline, Cochrane Collaboration Library and the National Library of Medicine's ClinicalTrials.gov. Inclusion criteria were ablation for CRLM with minimum 1 year follow-up and >10 patients, published between January 1994 and January 2010.

RESULTS

In all, 226 potentially relevant studies were identified, of which 75 met the inclusion criteria. Cryotherapy (26 studies) had local recurrence rates of 12-39%, with mean 1-, 3- and 5-year survival rates of 84%, 37% and 17%. The major complication rate ranged from 7% to 66%. Microwave ablation (13 studies) had a local recurrence rate of 5-13%, with a mean 1-, 3- and 5-year survival of 73%, 30% and 16%, and a major complication rate ranging from 3% to 16%. Radiofrequency ablation (36 studies) had a local recurrence rate of 10-31%, with a mean 1-, 3- and 5-year survival of 85%, 36% and 24%, with major complication rate ranging from 0% to 33%.

CONCLUSION

Ablative therapies offer significantly improved survival compared with palliative chemotherapy alone with 5-year survival rates of 17-24%. Complication rates amongst commonly used techniques are low.

Radiofrequency ablation as a treatment tool for liver metastases of colorectal origin

At diagnosis 10–25% of patients with colorectal liver metastases (CRLM) present as resectable disease. Liver resection is the gold standard treatment, resulting in a 5-year overall survival (OS) of 22–58%, local recurrence rates of 1.2–10.4% and a perioperative mortality of less than 5%. Multiple attempts have been made to assess the possible contribution of radiofrequency ablation (RFA) to improve OS and progression-free survival (PFS) in patients with unresectable colorectal liver metastases. The aim of this paper is to review the RFA literature in the setting of colorectal liver metastases: RFA with and without chemotherapy, RFA with and without resection, RFA for solitary unresectable CRLM, surgical and percutaneous imaging-guided RFA, RFA compared with chemotherapy. The reported OS, PFS, local recurrence rates, morbidity and mortality in these different settings are analyzed. This paper reflects on a possible role of RFA in resectable CRLM.

Radiofrequency ablation versus resection for liver tumours: an evidence-based approach to retrospective comparative studies

BACKGROUND

Recently randomized controlled trials have been advocated to compare radiofrequency ablation (RFA) and hepatic resection (HR) in resectable tumours and determine whether differences in observed survivals result from the heterogeneity in previous studies between RFA (treating unresectable lesions) and HR (treating lesions deemed resectable). We reviewed the literature that directly compares the treatments and employed an evidence-based approach to examine the data.

MATERIALS AND METHODS

All studies comparing RFA and HR were included. Primary outcomes were the overall survival (OS) and disease-free survival (DFS) at 3 and 5 years. A subgroup analysis was conducted for solitary or small tumors (<4 cm for colorectal metastases (CRM) or <5 cm for hepatocellular carcinoma (HCC)).

RESULTS

Most studies were retrospective. For CRM, HR was markedly superior to RFA in respect of 3- and 5-year OS as well as 5-year DFS including tumours smaller than 4 cm and solitary lesions. For HCC, HR was markedly superior to RFA for 3- and 5-year OS as well as 3-year DFS, and produced a better OS at 3 years for solitary lesions and DFS at 3 years for small tumours.

CONCLUSIONS

Multiple factors determine outcomes following treatment of liver tumours. Small or solitary lesions seem the most appropriate ones to study as this reduces the number of confounding variables, but even in these cases HR confers a better OS and DFS than RFA for both CRM and HCC. If our data are confirmed it will be important to examine other factors influencing the response.

Radiofrequency ablation as first-line treatment in patients with early colorectal liver metastases amenable to surgery

OBJECTIVE

Aiming at avoidance of futile surgery, we have tested whether radiofrequency ablation (RFA) may be used as first-line treatment in patients with colorectal metastases (CRLM) occurring within the first year after colorectal surgery.

SUMMARY BACKGROUND DATA

Surgical resection is the standard treatment in patients with CRLM. Major retrospective analyses have identified the interval between colorectal surgery and the occurrence of CRLM to be of prognostic importance. So far, it is unknown whether survival of the respective patients is hampered if RFA is used as first-line treatment.

METHODS

According to a clinical pathway, we have treated patients with CRLM detected within the first year after colorectal surgery preferentially by RFA (n=28). Resection (n=82) was performed in patients who were deemed not amenable to RFA due to number, size, or location of metastatic lesions. The diameter of lesions differed between the groups. All other characteristics of patients and lesions were comparable. Local recurrence and new hepatic lesions were treated with repeated RFA or surgery whenever possible.

RESULTS

Local recurrence at the site of ablation or resection occurred in 32% and 4% (P<0.001), new metastases apart from the site of previous treatment in 50% and 34% (P=0.179), and systemic recurrence in 32% and 37% (P=0.820) of the patients after RFA and surgery, respectively. Time to progression was significantly shorter in patients primarily treated with RFA (203 vs. 416 days; P=0.017). After primary treatment, 9 RFA patients and 8 surgery patients were amenable to repeated RFA or repeated surgery resulting in identical rates of disease-free patients and identical 3-year overall survival in both treatment groups: 67% and 60%, respectively; P=0.93.

CONCLUSIONS

Despite striking differences in local tumor recurrence and shorter time to progression, survival in patients with early CRLM does not depend on the mode of primary hepatic treatment.

Surgical resection versus non-surgical treatment for hepatic node positive patients with colorectal liver metastases

BACKGROUND

Involvement of hepatic lymph node in patients with colorectal liver metastases is associated with poor prognosis.

OBJECTIVES

To determine the benefits and harms of curative liver resection with lymphadenectomy versus other treatments for colorectal liver metastases with hepatic node involvement.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and LILACS until September 2009 for identifying the randomised trials.

SELECTION CRITERIA

We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing liver resection (alone or in combination with radiofrequency ablation or cryoablation) versus other treatments (neo-adjuvant chemotherapy, chemotherapy, or radiofrequency ablation) in patients with colorectal liver metastases with hepatic node involvement.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials for inclusion.

MAIN RESULTS

We were unable to identify any randomised clinical trial fulfilling the inclusion criteria of this review. We were also unable to identify any quasi-randomised or cohort studies, which could meaningfully answer this important issue.

AUTHORS' CONCLUSIONS

There is no evidence in the literature to assess the role of surgery versus other treatments for patients with colorectal liver metastases with hepatic node involvement. High quality randomised clinical trials are feasible and are necessary to determine the optimal management of patients with colorectal liver metastases with hepatic node involvement.

[Intraoperative radiofrequency ablation of liver metastases: age of reason]

Intraoperative radiofrequency ablation (IORA) is a surgical technique used to destroy liver metastases by heat. It is performed by a surgeon experienced in intraoperative ultrasounds. It has been officially registered in the French nomenclature of medical acts in 2009. Indications and results of IORA are very different from those of the percutaneous route used by radiologists. Ten years of experience have allowed to define IORA indications in complement to resection which remains the gold standard of liver surgery: 1) lesion no greater than 30 mm in diameter; 2) no proximity to a major portal structure; 3) use of a straight needle with overlapping heat volumes; 4) complete vascular exclusion (portal and sus-hepatic circulation) to treat para-sus-hepatic lesions; 5) requirement to spare parenchymal liver volume. Positive preliminary data of two prospective studies, the EORTCC CLOCC study and the ARF2003 study confirm that IORA complements surgery to obtain complete resection in a larger proportion of patients after chemotherapy induction.

Liver resection versus other treatments for neuroendocrine tumours in patients with resectable liver metastases

BACKGROUND

Neuroendocrine tumours are tumours of cells, which possess secretory granules and originate from the neuroectoderm. While liver resection is generally advocated in patients with resectable liver metastases, recent studies have shown good survival in patients with disseminated neuroendocrine tumours who underwent thermal ablation using radiofrequency.

OBJECTIVES

To determine the benefits and harms of liver resection versus other treatments in patients with resectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded and LILACS until July 2008 for identifying the randomised trials.

SELECTION CRITERIA

We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing liver resection (alone or in combination with radiofrequency ablation or cryoablation) versus other interventions (chemotherapy, hormonotherapy, or immunotherapy) and those comparing liver resection and thermal ablation (radiofrequency ablation or cryoablation) in patients with resectable liver metastases from neuroendocrine tumours for the review.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials for inclusion.

MAIN RESULTS

We were unable to identify any randomised clinical trial suitable for inclusion in this review. We were also unable to identify any quasi-randomised studies, cohort studies, or case-control studies that could inform meaningfully.

AUTHORS' CONCLUSIONS

There is no evidence from randomised clinical trials comparing liver resection versus other treatments in patients with resectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours. Liver resection appears to be the main stay curative treatment for neuroendocrine liver metastases based on non-randomised studies. Further randomised clinical trials comparing liver resection alone or in combination with chemoembolisation or radionuclide therapy are needed. Further randomised clinical trials comparing surgical resection and radiofrequency ablation in selected patients may also be appropriate.