Feasibility of adjuvant hepatic arterial infusion of chemotherapy after radiofrequency ablation with or without resection in patients with hepatic metastases from colorectal cancer

Mature Experiences Using Local Therapy for Oligometastases

Cancer is a heterogeneous disease, consisting of a spectrum of disorders ranging from local-only disease to those that are widely metastatic from their onset. The oligometastatic state, in which tumors harbor a limited number of metastases, may be curable in a subset of patients. The early success of surgical resection of hepatic metastases from colorectal cancer led to investigations into metastatectomy of other sites and, more recently, into the use of stereotactic ablative radiotherapy (SABR) for oligometastatic disease. This article reviews the data establishing the role of surgery for managing limited metastatic disease. Further, we review recent experiences using alternative local therapies, such as SABR, for oligometastases. This review also discusses ongoing trials evaluating local therapies for patients with a limited burden of metastatic cancer.

The prognosis of radiofrequency ablation versus hepatic resection for patients with colorectal liver metastases: A systematic review and meta-analysis based on 22 studies

BACKGROUND

Though hepatic resection (HR) is the standard local therapy for patients with colorectal cancer liver metastases (CRLMs), currently, radiofrequency ablation (RFA) may play an alternative role for elderly and vulnerable patients with various organ dysfunctions. This study aims to compare the prognosis of RFA and HR in treatment of CRLMs.

METHODS

A systematic search of PubMed, Embase, Cochrane Library and Web of Science up to October 1, 2020 was conducted for relevant studies that compared the prognosis of RFA with HR in the treatment of CRLMs. The primary outcomes were 30-day mortality, long-term recurrence, overall survival (OS) and disease-free survival (DFS). The secondary outcomes were various factors of OS, recurrence-free survival (RFS), survival, recurrence and complication.

RESULTS

A total of 22 studies including 4385 CRLM patients were identified. There was no significant difference between RFA and HR in 30-day mortality, with a pooled OR of 0.88 (95% CI 0.34-2.29; P = 0.80). CRLM patients undergoing RFA experienced significantly higher incidences of marginal and intrahepatic recurrence than HR, with pooled ORs of 7.09 (95% CI 4.56-11.2; 1251 pts) and 2.02 (95% CI 1.24-3.28; 1038 pts). In addition, RFA showed lower 1-, 3- and 5-yr OS rate than HR with pooled ORs of 0.39, 0.40 and 0.60 respectively. A lower 5-yr DFS rate was also found in RFA than HR group, with a pooled OR of 0.74 (95% CI 0.56-0.97; P = 0.03; 1231 pts). Multivariable analysis showed that tumor size, multiple tumors, age, primary node positive and metachronous metastasis were independent factors of OS, and multiple tumors was also an independent factor of RFS.

CONCLUSIONS

Though the 30-day mortality of RFA was equal to HR, RFA showed a higher recurrence rate and poor long-term survival outcomes for CRLM patients. Tumor size, multiple tumors, age, primary node positive and metachronous metastasis were independent factors of survival. However, the results were limited because of the inequality baseline characteristics between the comparative groups. Randomized or propensity score matching studies should be performed to clarify the effectiveness of RFA and to determine target populations that benefit most from RFA in the future.

Radiofrequency Ablation and Microwave Ablation in Liver Tumors: An Update

This article provides an overview of radiofrequency ablation (RFA) and microwave ablation (MWA) for treatment of primary liver tumors and hepatic metastasis. Only studies reporting RFA and MWA safety and efficacy on liver were retained. We found 40 clinical studies that satisfied the inclusion criteria. RFA has become an established treatment modality because of its efficacy, reproducibility, low complication rates, and availability. MWA has several advantages over RFA, which may make it more attractive to treat hepatic tumors. According to the literature, the overall survival, local recurrence, complication rates, disease-free survival, and mortality in patients with hepatocellular carcinoma (HCC) treated with RFA vary between 53.2 ± 3.0 months and 66 months, between 59.8% and 63.1%, between 2% and 10.5%, between 22.0 ± 2.6 months and 39 months, and between 0% and 1.2%, respectively. According to the literature, overall survival, local recurrence, complication rates, disease-free survival, and mortality in patients with HCC treated with MWA (compared with RFA) vary between 22 months for focal lesion >3 cm (vs. 21 months) and 50 months for focal lesion ≤3 cm (vs. 27 months), between 5% (vs. 46.6%) and 17.8% (vs. 18.2%), between 2.2% (vs. 0%) and 61.5% (vs. 45.4%), between 14 months (vs. 10.5 months) and 22 months (vs. no data reported), and between 0% (vs. 0%) and 15% (vs. 36%), respectively. According to the literature, the overall survival, local recurrence, complication rates, and mortality in liver metastases patients treated with RFA (vs. MWA) are not statistically different for both the survival times from primary tumor diagnosis and survival times from ablation, between 10% (vs. 6%) and 35.7% (vs. 39.6), between 1.1% (vs. 3.1%) and 24% (vs. 27%), and between 0% (vs. 0%) and 2% (vs. 0.3%). MWA should be considered the technique of choice in selected patients, when the tumor is ≥3 cm in diameter or is close to large vessels, independent of its size. IMPLICATIONS FOR PRACTICE: Although technical features of the radiofrequency ablation (RFA) and microwave ablation (MWA) are similar, the differences arise from the physical phenomenon used to generate heat. RFA has become an established treatment modality because of its efficacy, reproducibility, low complication rates, and availability. MWA has several advantages over RFA, which may make it more attractive than RFA to treat hepatic tumors. The benefits of MWA are an improved convection profile, higher constant intratumoral temperatures, faster ablation times, and the ability to use multiple probes to treat multiple lesions simultaneously. MWA should be considered the technique of choice when the tumor is ≥3 cm in diameter or is close to large vessels, independent of its size.

A radiologist's point of view in the presurgical and intraoperative setting of colorectal liver metastases

Multidisciplinary management of patients with metastatic colorectal cancer requires in each phase an adequate choice of the most appropriate imaging modality. The first challenging step is liver lesions detection and characterization, using several imaging modality ultrasound, computed tomography, magnetic resonance and positron emission tomography. The criteria to establish the metastases resectability have been modified. Not only the lesions number and site but also the functional volume remnant after surgery and the quality of the nontumoral liver must be taken into account. Radiologists should identify the liver functional volume remnant and during liver surgical procedures should collaborate with the surgeon to identify all lesions, including those that disappeared after the therapy, using intraoperative ultrasound with or without contrast medium.

Hepatic Artery Infusional Chemotherapy

Hepatic artery infusion (HAI) therapy is a well-studied and viable regional therapy for patients with hepatic metastases. Implantable pump devices may be safely placed intraarterially with minimal morbidity and HAI treatments can be used as an adjunct to systemic therapy. Future trials may address sequencing of regional and systemic therapies. However, HAI is not without complications and requires close monitoring and attention to detail but can offer reasonable control of liver tumor burden when managed jointly between medical and surgical oncologists. Herein we describe the technical aspects of HAI pump placement and review pertinent studies in primary and secondary liver tumors.

Phase II study on hepatic arterial infusion chemotherapy using percutaneous catheter placement techniques for liver metastases from colorectal cancer (JFMC28 study)

AIM

This prospective multicenter study aimed to evaluate the efficacy and adverse events of hepatic arterial infusion chemotherapy (HAIC) using percutaneous catheter placement techniques for liver metastases from colorectal cancer (CRC).

METHODS

We administered 5-fluorouracil at 1000 mg/m2 over 5 h via hepatic arterial infusion on a weekly schedule. The primary endpoint was the overall response rate (RR). The secondary endpoints were the overall survival (OS), progression-free survival (PFS) and toxicities.

RESULTS

Between February 2000 and March 2002, seventy-seven eligible patients were enrolled in this study. After a median of 26 treatment cycles, 4 patients achieved a complete response, 29 achieved a partial response, 28 had stable disease, 15 had progressive disease and the status of one patient was unknown. The overall RR was 42.9% and the disease control rate (DCR) was 79.2%. The median PFS and OS times were 203 and 560 days, respectively. The most common grade 3 or 4 hematological and non-hematological toxicities were total bilirubin level elevation (10.4%) and gamma-glutamyl transferase level elevation (10.4%). With regard to the relationship between the background factors and treatment outcomes, the DCR, RR, PFS and OS were different between patients with and without extrahepatic lesions (DCR: 86.5% vs 64%, RR: 46.2% vs 36.0%, PFS: 233 days vs 99 days, OS: 587 days vs 558 days).

CONCLUSION

The primary endpoint of this study was not met. HAIC using percutaneous catheter placement techniques did not improve the RR for liver metastasis from CRC.

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.

Mechanical disruption of tumors by iron particles and magnetic field application results in increased anti-tumor immune responses

The primary tumor represents a potential source of antigens for priming immune responses for disseminated disease. Current means of debulking tumors involves the use of cytoreductive conditioning that impairs immune cells or removal by surgery. We hypothesized that activation of the immune system could occur through the localized release of tumor antigens and induction of tumor death due to physical disruption of tumor architecture and destruction of the primary tumor in situ. This was accomplished by intratumor injection of magneto-rheological fluid (MRF) consisting of iron microparticles, in Balb/c mice bearing orthotopic 4T1 breast cancer, followed by local application of a magnetic field resulting in immediate coalescence of the particles, tumor cell death, slower growth of primary tumors as well as decreased tumor progression in distant sites and metastatic spread. This treatment was associated with increased activation of DCs in the draining lymph nodes and recruitment of both DCs and CD8(+)T cells to the tumor. The particles remained within the tumor and no toxicities were observed. The immune induction observed was significantly greater compared to cryoablation. Further anti-tumor effects were observed when MRF/magnet therapy was combined with systemic low dose immunotherapy. Thus, mechanical disruption of the primary tumor with MRF/magnetic field application represents a novel means to induce systemic immune activation in cancer.

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.

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.

Efficacy and safety of hepatic arterial infusion of fluorouracil with leucovorin as salvage treatment for refractory liver metastases from colorectal cancer

BACKGROUND/AIMS

Limited options remain for patients with metastatic colorectal cancer (CRC) after failure of standard systemic chemotherapy. Readministration of chemotherapeutic agents by hepatic arterial infusion (HAI) has the rationale of providing higher concentrations of chemotherapeutic agents to hepatic metastases. The present study was conducted to evaluate the efficacy and safety of HAI of fluorouracil with leucovorin (HAI 5-FU/LV) for patients with liver metastases from CRC.

METHODS

Fourteen patients with liver metastases from CRC who received HAI 5-FU/LV after failure of systemic chemotherapy containing fluorouracil and leucovorin were identified and their medical records were reviewed.

RESULTS

Of 10 patients evaluable for response, one partial response, six stable disease, and three progressive disease were reported. Additionally, the overall response and disease control rates were 7% and 50%, respectively. The median time to progression was 4.3 months (range, 2.9 to 5.6), to hepatic progression was 5.8 months (range, 4.7 to 6.9), and to extrahepatic progression was 5.8 months (range, 2.3 to 9.2). No grade 3/4 hematologic toxicities occurred and one case of abdominal pain and two cases of oral mucositis were the only grade 3 nonhematologic toxicities. Catheter-related complications occurred in three patients: one thrombosis, one infection, and one displacement.

CONCLUSIONS

HAI 5-FU/LV was well tolerated and showed modest efficacy for patients with liver metastases from refractory CRC. Readministration of previously used chemotherapeutic agents via the hepatic artery could be an effective salvage option and warrants further investigation in a prospective trial.

Adjuvant radioimmunotherapy after radiofrequency ablation of colorectal liver metastases in an experimental model

PURPOSE

Radiofrequency ablation (RFA) has shown to improve survival in patients not eligible for surgical resection of colorectal liver metastases. However, recurrences after RFA are a major problem. Adjuvant radioimmunotherapy (RIT) after surgical resection of liver metastases has shown to improve survival. The aim of the present study was to test the hypothesis that adjuvant RIT might be an effective way to prevent recurrent liver metastases after RFA in an experimental model.

METHODS

Tumours in the liver were induced by intrahepatic injection of 300,000 CC531 cells in male Wag/Rij rats (n = 60). Ten days later, the intrahepatic tumours were treated with RFA. Adjuvant RIT ((177)Lu-labelled monoclonal antibody MG1 at 300 MBq/kg) was administered intravenously either at the day of RFA (day 10) or 7 days later. Control rats received no treatment. Primary endpoint was survival.

RESULTS

Administration of (177)Lu-MG1 resulted in a transient decrease in body weight, compared to no adjuvant treatment. However, no other signs of clinical discomfort were registered. Log rank test showed that the survival curves of the groups treated with RIT, either at day 10 or day 17, did not differ significantly from the survival curve of the rats that did not receive adjuvant treatment (P = 0.902).

CONCLUSION

This study shows that adjuvant RIT does not increase survival after RFA of colorectal liver metastases in rats.

American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer

PURPOSE

To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM).

METHODS

The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library.

RESULTS

Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches.

CONCLUSION

There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

RF ablation with adjuvant therapy: comparison of external beam radiation and liposomal doxorubicin on ablation efficacy in an animal tumor model

PURPOSE

To determine the critical thermal dosimetry and relative efficacy for RF ablation combined with external beam radiation (XRT) or liposomal doxorubicin (LD), in an animal tumor model.

MATERIALS AND METHODS

This study was performed in two phases, in 13-18 mm diameter R3230 tumors subcutaneously implanted into Fischer rats. In phase 1, tumors (n = 30) were randomized into six groups. RF energy (titrated to 70 degrees C tip temperature) was applied for either 2.5 or 5 min (n = 15, each group). For each duration, one of three adjuvant therapies was applied (n = 5, each): no therapy (control), LD (1 mg intravenously, 30 min post-RF), or XRT (20 Gy at 1 Gy min(-1), within 2 h post-RF), with sacrifice at 48 h for pathologic analysis. In phase 2, thermal mapping was performed in 20 tumors throughout RF application (70 degrees C; 5 min), at 1.5-7 mm distances from the active electrode tip. Temperature profiles throughout the tumor were constructed and were used to interpolate temperatures over time at the critical ablation margin, to derive maximum threshold temperature, AUC (area under the curve) and CEM(43) (cumulative equivalent minutes at 43 degrees C). Ablation sizes and all calculated values were compared within and across experimental groups using MANOVA statistics with pair-wise T-test for individual comparisons.

RESULTS

RF/XRT produced the largest coagulation (11.7 +/- 1.5 mm at 2.5 min, >or=15 +/- 0.7 mm at 5 min), followed by RF/LD, and then RF alone (p < 0.001 for all comparisons). RF/XRT demonstrated temperature threshold decreases from RF alone of 11.7 +/- 0.01 degrees C and 12.7 +/- 0.38 degrees C at 2.5 and 5 min respectively (with absolute thresholds of 42 degrees C for XRT compared to 52 degrees C for RF alone). RF/LD had decreases of 4.0 degrees C at 2.5 min and 4.4 degrees C at 5 min. Thermal dose requirements (AUC) decreased by 7.79% or 9.28% for RF/LD compared to >or=19.36% or 25.82% for RF/XRT at 2.5 and 5 min (p < 0.001). CEM(43) values followed similar patterns (p < 0.001), but with a reduction of 10(1) and 10(4) in magnitude for RF/LD and RF/XRT therapies at 5 min, respectively.

CONCLUSIONS

For a standardized RF dose, the combination of high dose XRT and RF increased ablation size compared to RF and liposomal doxorubicin or RF alone. Increased ablation size is more closely associated with decreased temperature threshold necessary to induce coagulation, rather than the total thermal dose.

Radiofrequency ablation of primary and metastatic liver tumors: a critical review of the literature

BACKGROUND

Surgical resection is the treatment of choice for hepatic tumors; however, for various reasons, the vast majority of patients are not operative candidates. As a result, several local ablative therapies have emerged as alternatives to resection or as adjuncts in total oncologic care. Presently, the most widely employed liver-directed treatment is radiofrequency thermal ablation.

METHODS

To define the current status of radiofrequency ablation (RFA), the authors reviewed available safety and efficacy data from select studies on RFA. A MEDLINE search was performed using the keywords "tumor type" + "radiofrequency ablation" + "survival." Only those studies containing long-term survival data on greater than 50 patients were included in this analysis.

CONCLUSIONS

Although RFA has been readily adopted into treatment paradigms, more rigorous trials are needed to solidify its place in the armamentarium of therapeutic strategies for hepatic malignancy.

Combining partial liver resection and local ablation of liver tumours: a preliminary Dutch experience

BACKGROUND

The combination of partial liver resection and radiofrequency ablation (RFA) is a novel concept in the treatment of unresectable liver malignancies. The aim of this study is to evaluate the results of this combined strategy in the Netherlands.

METHODS

Thirty-five patients treated with a combination of partial liver resection and RFA were identified from a prospectively registered pooled multicentre database. All patients were operated between June 1999 and November 2003 in 8 medical centres in The Netherlands. Main outcome parameters were morbidity, mortality, local success rate, and survival.

RESULTS

Thirty-seven operations were performed in 35 patients. The group consisted of 20 male and 15 female patients with a median age of 59 years (range 41-76). Seventy-six lesions were resected and RFA was performed to ablate 82 unresectable liver tumours. Twelve patients developed a total of 24 complications, resulting in an overall perioperative morbidity rate of 32%. In two patients major complications resulted in postoperative death (postoperative mortality rate 5.4%). Local success rate after RFA was 88% and the estimated 1-, 2- and 3-year overall survival rates were 84%, 70% and 43%, respectively.

CONCLUSION

This strategy should only be performed following strict patient selection and within the context of prospective clinical trials.

RFA for Liver Tumors: Does It Really Work?

The use of radiofrequency ablation (RFA) is increasing in the treatment of both primary and metastatic hepatic tumors. However, the role of RFA has yet to be clearly defined in patients who are still considered amenable to surgical intervention. Future prospective studies are needed to define whether RFA can be used as an alternative to surgery in certain patient populations. In the interim, radiofrequency ablation technology will continue to advance and serve as both a palliative and potentially curative intervention for individuals with hepatic tumors.

A phase II study of radiofrequency ablation of unresectable metastatic colorectal cancer with hepatic arterial infusion pump chemotherapy

BACKGROUND

Adjuvant hepatic arterial infusion (HAI) chemotherapy has been demonstrated to improve disease-free survival for colorectal cancer liver metastases. It is unclear if this improvement can be extrapolated to unresectable liver metastases that undergo RFA. The aim of this study was to evaluate the combination of RFA and HAI chemotherapy for unresectable liver metastases.

METHODS

Phase II study was conducted from November 2000 to July 2003 evaluating the use of complete extirpation by RFA, or resection/ablation with adjuvant HAI consisting of FUDR for 6 months.

RESULTS

Twenty-one patients had successful resection and/or RFA with HAI pump, which included treatment for 100 liver metastases (22 resected, 78 ablated; mean 4.8 tumors/patient). Four of 21 patients completed the full 6-month course of HAI. Six of these patients had 12 adverse events related to HAIP, most commonly elevated liver enzymes. After a median follow-up of 24 months, the median liver specific disease-free and overall survival rates for the entire group were 17 and 30 months, respectively.

CONCLUSIONS

Given the complications and toxicity associated with HAI pump chemotherapy, adjuvant HAI chemotherapy after RFA of liver metastases may not be warranted as a first line treatment option.

Technical complications and durability of hepatic artery infusion pumps for unresectable colorectal liver metastases: an institutional experience of 544 consecutive cases

BACKGROUND

Hepatic arterial infusion pump chemotherapy is an important component in the treatment of patients with hepatic metastases. Successful use of a hepatic arterial infusion pump requires a low technical complication rate. We evaluated the complications and longterm durability of these devices at our institution.

STUDY DESIGN

Between April 1986 and March 2001, 544 patients underwent hepatic arterial infusion pump placement for treatment of unresectable colorectal liver metastases. Patient- and pump-related data were collected by chart review. Pump-related complications, duration of pump function, and overall patient survival were recorded.

RESULTS

Median patient survival was 24 months after pump placement. The incidences of pump failure were 9% at 1 year and 16% at 2 years. Pump complications occurred in 120 (22%) of the patients. Complications that occurred early after operation (< 30 days) were more likely to be salvaged than those occurring late (70% versus 30%, p < 0.001). Increased pump complication rates occurred in the setting of variant arterial anatomy (28% versus 19%, p = 0.02), when the catheter was inserted into a vessel other than the gastroduodenal artery (42% versus 21%, p = 0.004), if the pump was placed during the first half of the study period (1986 to 1993, 25% versus 1994 to 2001, 18%; p = 0.05), and if the surgeon had performed fewer than 25 earlier procedures (< 25, 31% versus > or = 25, 19%; p < 0.002).

CONCLUSIONS

In this large single institution experience, pump-related complications were low, the majority of early pump complications were salvaged, and pump complication rates improved as institutional experience accumulated. Longterm durability of pump function was excellent.

Local recurrence after hepatic radiofrequency coagulation: multivariate meta-analysis and review of contributing factors

OBJECTIVE

The purpose of this study was to analyze the factors that influence local recurrence after radiofrequency coagulation of liver tumors.

SUMMARY BACKGROUND DATA

Local recurrence rate varies widely between 2% and 60%. Apart from tumor size as an important risk factor for local recurrence, little is known about the impact of other factors.

METHODS

An exhaustive literature search was carried out for the period from January 1, 1990 to January 1, 2004. Only series with a minimal follow-up of 6 months and/or mean follow-up of 12 months were included. Univariate and multivariate meta-analyses were carried out.

RESULTS

Ninety-five independent series were included, allowing the analysis of the local recurrence rate of 5224 treated liver tumors. In a univariate analysis, tumor-dependent factors with significantly less local recurrences were: smaller size, neuroendocrine metastases, nonsubcapsular location, and location away from large vessels. Physician-dependent favorable factors were: surgical (open or laparoscopic) approach, vascular occlusion, general anesthesia, a 1-cm intentional margin, and a greater physician experience. In a multivariate analysis, significantly less local recurrences were observed for small size (P < 0.001) and a surgical (versus percutaneous) approach (P < 0.001).

CONCLUSIONS

Radiofrequency coagulation by laparoscopy or laparotomy results in superior local control, independent of tumor size. The percutaneous route should mainly be reserved for patients who cannot tolerate a laparoscopy or laparotomy. The short-term benefits of less invasiveness for the percutaneous route do not outweigh the longer-term higher risk of local recurrence.

Liver-directed therapies in colorectal cancer

The liver is the most common site of metastatic colorectal cancer (CRC) and the status of this organ is an important determinant of overall survival in patients with advanced disease. Complete resection of hepatic CRC metastases can provide a long-term cure for some patients, but the majority of liver metastases are not amenable to such surgery. Furthermore, most patients after curative resection ultimately suffer from recurrence, and the majority of such failures occur in the liver. Various ablative techniques can achieve local control of tumor after incomplete resection or for palliation. Tumor ablation currently has a secondary therapeutic role, as there is no evidence that it can achieve long-term survival comparable to surgical resection. Regional chemotherapy delivers tumoricidal agents in a selective fashion, minimizing systemic toxicity and damage to normal liver cells. Chemotherapy agents delivered through the hepatic artery can extend time to liver recurrence after curative resection and may prolong survival both in the adjuvant setting and when given to patients with unresectable disease. Molecular-based therapies, such as gene delivery and oncolytic viruses, provide promise for curative outcomes in patients with advanced disease.

Reduced tumor growth with combined radiofrequency ablation and radiation therapy in a rat breast tumor model

PURPOSE

To determine whether use of combined radiofrequency (RF) ablation and external-beam radiation therapy increases end-point survival beyond that with either RF ablation or radiation therapy alone in an animal tumor model.

MATERIALS AND METHODS

With a protocol approved by the institutional animal care and use committee, R3230 mammary adenocarcinoma (12.5 mm +/- 0.6 [standard deviation]) was implanted subcutaneously into 107 female Fischer 344 rats. Initially, 42 tumors were randomized into four treatment groups: (a) RF ablation (70 degrees C for 5 minutes) alone, (b) RF ablation followed by radiation therapy with a total dose of 20 Gy, (c) 20-Gy radiation alone, and (d) no treatment. Another 19 tumors were randomized to receive (e) RF ablation (70 degrees C for 5 minutes) followed by 5-Gy radiation, (f) 5-Gy radiation alone, or (g) no treatment. Animals were followed up until survival end point (either until tumor growth to 30 mm in diameter, or for 120 days if no tumor was seen in mammary fat pad or chest wall). Results were analyzed with the Kaplan-Meier method. Histopathologic analysis was performed in 15 additional tumors at survival end point and 18 other representative tumors at other specified end points.

RESULTS

Combined RF ablation and 20-Gy radiation resulted in complete local control in nine (82%) of 11 tumors, compared with one (9%) of 11 tumors treated with RF ablation alone and one (17%) of six treated with RF ablation and 5-Gy radiation (P < .001). No local control was achieved in rats with radiation therapy alone or in controls. Median end-point survival was 12 days for controls, 20 days with RF ablation or 5-Gy radiation alone, 30 days with RF ablation plus 5-Gy radiation, 40 days with 20-Gy radiation alone, and 120 days with RF ablation plus 20-Gy radiation. Mean end-point survival was 13 days +/- 5 (standard deviation) for the control group, 34 days +/- 31 with RF ablation alone, and 43 days +/- 16 with 20-Gy radiation alone. Mean survival was significantly greater with 20-Gy radiation and RF ablation combined: 94 days +/- 34 (P < .001 compared with all other groups). Mean survival for rats that received 5-Gy radiation with RF ablation versus without was 46 days +/- 37 versus 24 days +/- 11, respectively.

CONCLUSION

Combined RF ablation and external-beam radiation therapy increased animal survival compared with that with either of the treatments alone or with no treatment.

New chemotherapeutic strategies in colorectal cancer

Since colorectal cancer is the second most prevalent cancer worldwide, its treatment remains a major challenge for researchers, gastroenterologists and oncologists. Despite curative resections, half of all patients diagnosed with colorectal cancer die because of their underlying disease. Integral chemotherapeutic components of standard regimens are 5-fluorouracil (5-FU), its modulation by folinic acid and irinotecan or oxaliplatin. All these drugs sequentially given have results in terms of median overall survival of more than 20 months in the palliative treatment of advanced colorectal cancer. Oral fluoropyrimidines, currently under clinical investigation, are likely to substitute continuous 5-FU. Inhibitors of growth factor receptors or their signaling may further prolong disease-free and overall survival rates. Preliminary evidence exists that improved adjuvant and neoadjuvant chemotherapy strategies may further improve the prognosis, mainly because more patients are able to go for primary or secondary surgery with curative intent.

Morbidity of adjuvant hepatic arterial infusion pump chemotherapy in the management of colorectal cancer metastatic to the liver

BACKGROUND

Surgical resection remains the treatment of choice for patients with colorectal cancer metastatic to the liver. Hepatic arterial infusion pump (HAIP) chemotherapy in combination with surgical resection has been demonstrated in a recent study to improve disease-free and overall survival for patients with colorectal cancer metastatic to the liver. Other reports, however, have indicated significant toxicity related to HAIP chemotherapy in the form of biliary sclerosis. Thus, the value of adjuvant HAIP chemotherapy following hepatic resection or ablation remains controversial. The aim of this study was to examine the survival and toxicity in a single institutional experience with adjuvant HAIP chemotherapy.

METHODS

Review of a prospective hepatobiliary database was performed. HAIP were placed in the standard technique following resection and/or radiofrequency ablation (RFA) of all liver metastases. Patients received floxuridine (FUDR) via the HAIP at standard doses. Complications were graded according to a standard 5-point grading scale. Statistical analysis was performed by chi(2) test.

RESULTS

Thirty-four of 86 patients underwent placement of HAIP at the time of hepatic resection or ablation between January 1999 and November 2002. The HAIP group demonstrated a significantly greater (P <0.05) number (median 5 vs. 2) and size (median 5 cm vs. 3 cm) of hepatic lesions compared to the group without HAIP. The HAIP group experienced a greater frequency of complications (53% vs. 33%), with 6 (18%) patients in the HAIP group demonstrating biliary sclerosis. There were no deaths within 30 days of surgery. Median survival was similar in both groups (HAIP 20 months, no HAIP 24 months).

CONCLUSIONS

Patients in the HAIP group had significantly worse overall predictors of outcome in metastatic colorectal cancer, yet the median overall survival in both groups was similar. However, adjuvant HAIP chemotherapy was associated with significantly greater morbidity. Given the availability of newer active systemic agents and regimens, the value of adjuvant HAIP chemotherapy remains controversial.

Hepatic arterial chemotherapy for colorectal cancer liver metastases: a review of advances in 2003

PURPOSE OF REVIEW

During 2003, two new randomized trials comparing fluoropyrimidine-based hepatic arterial chemotherapy (HAC) with systemic chemotherapy were published. These new data will be reviewed in the context of previous trials and new observations of novel approaches involving HAC.

RECENT FINDINGS

The large Medical Research Council (MRC)/European Organization for the Research and Treatment of Cancer (EORTC) and the smaller Cancer and Leukaemia Group B (CALGB) trials reported conflicting conclusions. Lack of difference in response rates and survival outcomes was noted by the European trial groups whereas the contrary was reported by the US investigators, with statistically significant difference in response rates of 48% and 25% and median survival of 22.7 months and 19.8 months, respectively, being observed, favoring HAC. Early studies testing incorporation of irinotecan or oxaliplatin into HAC, either as additional systemic chemotherapy or as integral components of the HAC infusional regimen, confirmed feasibility, safety, and efficacy, with response rates between 30% and 60% being reported in some series. Other studies showed that combination with internal irradiation with lipiodol I-131 and biologic agents, eg, replication-selective adenovirus and cytokines, could be achieved with tolerable toxicity. Molecular prognostic factors that may help tailor treatment for individual patients were being investigated and low expression of thymidylate synthase (TS) and p21 was shown to correlate with better outcome, whereas patients with positive TS seemed to derive more benefit from HAC plus systemic chemotherapy than systemic chemotherapy alone.

SUMMARY

These studies confirmed that fluoropyrimidine-based HAC cannot be recommended routinely outside clinical trial as yet, but this treatment has its own merits and will continue to evolve with the availability of novel chemotherapeutic and biologic agents. Further studies into molecular prognostic factors will eventually define the role of HAC by selecting the right drug and the best route of administration for an individual patient.

Radiofrequency ablation of primary and metastatic hepatic malignancies

Radiofrequency interstitial tissue ablation is a local ablative therapy in which tumors are destroyed in situ by thermal coagulation and protein denaturation through frictional heating produced by tissue ionic agitation from high-frequency alternating current. This technology can be used to destroy primary and metastatic hepatic lesions generally considered nonresectable or nonoperable, thus providing patients with these tumors, who have few treatment options, a relatively safe and effective alternative with the potential for improved chance of survival. Knowledge of the broad spectrum of potential complications associated with radiofrequency ablation (RFA) is essential for prevention, early detection, and proper management. Combining RFA with other modalities such as surgical resection or hepatic artery infusional chemotherapy is feasible, has increased the pool of operable patients, and may improve treatment efficacy and clinical outcome in properly selected patients. The approach to perform RFA percutaneously, laparoscopically, or during laparatomy should take into consideration tumor characteristics, imaging and technical limitations, and the role of other treatment modalities. Therefore, patients considered for RFA should be evaluated within the context of a multidisciplinary approach to insure proper patient selection and coordination of adjunct therapy.

Ultrasound imaging of flow patterns in liver metastases from colorectal cancer

BACKGROUND

The ability of colour Doppler, power Doppler and echo-enhanced Doppler imaging to detect the blood flow in liver metastases from colorectal cancer was investigated. An evaluation was then made to determine whether the flow pattern could be used as an indication of disease elsewhere.

METHODS

Forty-two patients with hepatic metastases from colorectal cancer were examined, 8 of whom had local recurrence of their colorectal cancer. Seventy-seven liver metastases were evaluated with colour Doppler and power Doppler, and the presence or absence of a Doppler signal in the halo or centre was noted. Forty-three of these metastases were further examined after contrast media echo-enhancement.

RESULTS

Signals from the peripheral halo were detected by colour Doppler imaging in 34% of the metastases, and in 77% by power Doppler (P < 0.001). Use of contrast media enhanced the power Doppler detection rate to 98% (P < 0.005). Central signals were detected by power Doppler in 12 patients, 8 (66%) of whom also had local recurrence. Thirty patients had neither local recurrence nor central signals, as detected by power Doppler (P < 0.001).

CONCLUSION

The results indicate that the halo in liver metastases corresponds to the vascular flow. There seems to be an association between metastases showing a central power Doppler flow and local tumour recurrence.