Hepatic resection but not radiofrequency ablation results in tumor growth and increased growth factor expression

Radiofrequency ablation in the treatment of hepatocellular carcinoma

OBJECTIVE

The purpose of this article is to discuss the use, comparative efficacy, and research progress of radiofrequency ablation (RFA), alone or in combination with other therapies, for the treatment of hepatocellular carcinoma (HCC).

METHOD

To search and summarize the basic and clinical studies of RFA in recent years.

RESULTS

RFA is one of the radical treatment methods listed in the guidelines for the diagnosis and treatment of HCC. It has the characteristics of being minimally invasive and safe and can obtain good local tumor control, and it can improve the local immune ability, improve the tumor microenvironment and enhance the efficacy of chemotherapy drugs. It is commonly used for HCC treatment before liver transplantation and combined ALPPS and hepatectomy for HCC. In addition, the technology of RFA is constantly developing. The birth of noninvasive, no-touch RFA technology and equipment and the precise RFA concept have improved the therapeutic effect of RFA.

CONCLUSION

RFA has good local tumor control ability, is minimally invasive, is safe and has other beneficial characteristics. It plays an increasingly important role in the comprehensive treatment strategy of HCC. Whether RFA alone or combined with other technologies expands the surgical indications of patients with HCC and provides more benefits for HCC patients needs to be determined.

Heat Stress and Thermal Ablation Induce Local Expression of Nerve Growth Factor Inducible (VGF) in Hepatocytes and Hepatocellular Carcinoma: Preclinical and Clinical Studies

The purposes of this study were to test the hypothesis that heat stress and hepatic thermal ablation induce nerve growth factor inducible (VGF) and to determine intrahepatic versus systemic VGF expression induced by thermal ablation in vivo and in patients. Hepatocytes and HCC cells were subjected to moderate (45°C) or physiologic (37°C) heat stress for 10 min and assessed for VGF expression at 0-72 h post-heat stress (n ≥ 3 experiments). Orthotopic N1S1 HCC-bearing rats were randomized to sham or laser thermal ablation (3 W × 90 s), and liver/serum was harvested at 0-7 days postablation for analysis of VGF expression (n ≥ 6 per group). Serum was collected from patients undergoing thermal ablation for HCC (n = 16) at baseline, 3-6, and 18-24 h postablation and analyzed for VGF expression. Data were analyzed using ordinary or repeated-measures one-way analysis of variance and post hoc pairwise comparison with Dunnett's test. Moderate heat stress induced time-dependent VGF mRNA (3- to 15-fold; p < 0.04) and protein expression and secretion (3.1- to 3.3-fold; p < 0.05). Thermal ablation induced VGF expression at the hepatic ablation margin at 1 and 3 days postablation but not remote from the ablation zone or distant intrahepatic lobe. There was no detectable serum VGF following hepatic thermal ablation in rats and no increase in serum VGF following HCC thermal ablation in patients at 3-6 and 18-24 h postablation compared to baseline (0.71- and 0.63-fold; p = 0.27 and p = 0.16, respectively). Moderate heat stress induces expression and secretion of VGF in HCC cells and hepatocytes in vitro, and thermal ablation induces local intrahepatic but not distant intrahepatic or systemic VGF expression in vivo.

Radiofrequency ablation versus resection for technically resectable colorectal liver metastasis: a propensity score analysis

BACKGROUND

Liver resection is the first-line treatment for patients with resectable colorectal liver metastasis (CRLM), while radiofrequency ablation (RFA) can be used for small unresectable CRLM because of disease extent, poor anatomical location, or comorbidities. However, the long-term outcomes are unclear for RFA treatment in resectable CRLM. This study aimed to compare the recurrence rates and prognosis between resectable CRLM patients receiving either liver resection or RFA.

METHODS

Consecutive patients who underwent RFA or hepatic resection from November 2010 to December 2015 were assigned in this retrospective study. Propensity score analysis was used to eliminate baseline differences between groups. Survival and recurrence rates were compared between patients receiving liver resection and RFA.

RESULTS

With 1:2 ratio of propensity scoring, 46 patients in the RFA group and 92 in the resection group were successfully matched. Overall survival was similar between the two groups, but the resection group had a higher disease-free survival (median, 22 months vs. 14 months). Whereas among patients with a tumor size of ≤ 3 cm, disease-free survival was similar in the two groups (median, 24 months vs. 21 months). Compared to the resection group, the RFA group had a higher rate of intrahepatic recurrence (34.8% vs. 12.0%) and a shorter recurrence free period. The local and systemic recurrence rate and recurrence-free period for the same were insignificant in the two groups. Poor disease-free survival was associated with RFA, T4, tumor diameter > 3 cm, and lymph node positivity.

CONCLUSION

Among patients with technically resectable CRLM, resection provided greater disease-free survival, although both treatment modalities provided similar overall survival.

Heat Stress and Hepatic Laser Thermal Ablation Induce Hepatocellular Carcinoma Growth: Role of PI3K/mTOR/AKT Signaling

Purpose To determine if heat stress and hepatic laser thermal ablation induce hepatocellular carcinoma (HCC) growth and to identify growth factors induced by heat stress. Materials and Methods Non-heat-stressed HCC cells were cocultured with HCC cells or hepatocytes that were heat stressed at 37°C (physiologic), 45°C (moderate), or 50°C (severe) for 10 minutes and proliferation monitored with bioluminescence imaging for up to 6 days after heat stress (three experiments). Rats bearing orthotopic N1S1 HCC were randomly assigned to undergo immediate sham or laser thermal (3 W for 60 or 90 seconds; hereafter, 3W×60s and 3W×90s, respectively) ablation of the median (local) or left (distant) hepatic lobe, and tumor growth was monitored with magnetic resonance imaging for up to 18 days after ablation (six or more rats per group). Experiments were repeated with rats randomly assigned to receive either the adjuvant phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor (NVP-BEZ235) or the vehicle control. Heat-stressed HCC cells and hepatocytes were analyzed by using microarray or quantitative real-time polymerase chain reaction analysis for growth factor expression (three or more experiments). Groups were compared by using one- or two-way analysis of variance, and post hoc pairwise comparison was performed with the Dunnett test. Results There were more non-heat-stressed HCC cells when cells were cocultured with cells subjected to moderate but not physiologic or severe heat stress (P < .001 for both). Local intrahepatic N1S1 tumors were larger at day 18 in the 3W×60s (mean, 3102 mm³ ± 463 [standard error]; P = .004) and 3W×90s (mean, 3538 mm³ ± 667; P < .001) groups than in the sham group (mean, 1363 mm³ ± 361) but not in distant intrahepatic tumors (P = .31). Adjuvant BEZ235 resulted in smaller N1S1 tumors in the BEZ235 and laser thermal ablation group than in the vehicle control and laser thermal ablation group (mean, 1731 mm³ ± 1457 vs 3844 mm³ ± 2400, P < .001). Moderate heat stress induced expression of growth factors in HCC cells and hepatocytes, including heparin-binding growth factor, fibroblast growth factor 21, and nerve growth factor (range, 2.9-66.9-fold; P < .05). Conclusion Moderate heat stress and laser thermal ablation induce hepatocellular carcinoma growth, which is prevented with adjuvant PI3K/mTOR/protein kinase B inhibition.

Anterior approach for right hepatectomy with hanging maneuver for hepatocellular carcinoma: a multi-institutional propensity score-matching study

BACKGROUND

This multi-institutional study aimed to assess the benefits of anterior approach for right hepatectomy with hanging maneuver (ARH-HM) for hepatocellular carcinoma (HCC) compared with conventional right hepatectomy (CRH).

METHODS

From January 2000 to December 2012, 306 patients with HCC ≥5 cm were divided into two groups: ARH-HM (n = 104) and CRH (n = 202).

RESULTS

After one-to-one propensity score-matched analysis, 72 ARH-HM and 72 CRH patients presented comparable background factors. Patients in the ARH-HM group demonstrated significantly less intraoperative blood loss (480 vs. 1,242 g, P < 0.001) and a lower frequency of red cell concentrate transfusion (21.1% vs. 50.7%, P < 0.001) compared with patients in the CRH group. The 5-year overall survival rate was significantly better in the ARH-HM group compared with the CRH group (50.2% vs. 31.4%, P = 0.021). Limited to patients with HCC ≥10 cm, recurrence-free and overall survival of the ARH-HM group was significantly greater than those of the CRH group.

CONCLUSION

In comparison with CRH, ARH-HM for large HCC can provide better overall survival rates with a decrease in intraoperative blood loss and transfusion rates. Survival impact was evident especially in patients with HCC ≥10 cm.

Reconsideration of the indications for adjuvant chemotherapy for liver metastases from colorectal cancer after initial hepatectomy

BACKGROUND

The effectiveness of perioperative adjuvant chemotherapy for colorectal cancer liver metastasis (CRLM) remains a matter of debate. Despite the lack of clear evidence supporting its effectiveness after curative hepatectomy, adjuvant chemotherapy has been widely used clinically. The purpose of this study was to clarify the indications for adjuvant chemotherapy in order to develop an appropriate treatment strategy for CRLM.

METHODS

The clinicopathological factors of 110 patients who underwent initial hepatectomy for CRLM between April 2000 and March 2010 were retrospectively analyzed. The prognostic factors of CRLM were identified and then CRLM was stratified according to the number of prognostic factors into the high-score group (H-group: score 2 or 3) and the low-score group (L-group: score 0 or 1), and the effectiveness of adjuvant chemotherapy was analyzed in each group.

RESULTS

Multivariate analysis identified pT4 (p = 0.0047), lymph node metastasis in colorectal cancer (CRC) (p = 0.0165), and H2-classification (p = 0.0051) as factors related to a poor prognosis. The overall 5-year survival rate was markedly higher in the L-group (68 %) than in the H-group (26 %, p < 0.0001). Moreover, in the L-group, patients who did not receive adjuvant chemotherapy had the same prognosis as those who received adjuvant chemotherapy. As for recurrence, tumor relapse more often was treated by resection in the L-group than in the H-group (p = 0.0339).

CONCLUSIONS

Adjuvant chemotherapy did not improve overall survival and disease-free survival in patients with no more than two factors of the H2-classification, invasion depth pT4, and lymph node metastasis in CRC.

Value of radiofrequency ablation in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignant disease that substantially affects public health worldwide. It is especially prevalent in east Asia and sub-Saharan Africa, where the main etiology is the endemic status of chronic hepatitis B. Effective treatments with curative intent for early HCC include liver transplantation, liver resection (LR), and radiofrequency ablation (RFA). RFA has become the most widely used local thermal ablation method in recent years because of its technical ease, safety, satisfactory local tumor control, and minimally invasive nature. This technique has also emerged as an important treatment strategy for HCC in recent years. RFA, liver transplantation, and hepatectomy can be complementary to one another in the treatment of HCC, and the outcome benefits have been demonstrated by numerous clinical studies. As a pretransplantation bridge therapy, RFA extends the average waiting time without increasing the risk of dropout or death. In contrast to LR, RFA causes almost no intra-abdominal adhesion, thus producing favorable conditions for subsequent liver transplantation. Many studies have demonstrated mutual interactions between RFA and hepatectomy, effectively expanding the operative indications for patients with HCC and enhancing the efficacy of these approaches. However, treated tumor tissue remains within the body after RFA, and residual tumors or satellite nodules can limit the effectiveness of this treatment. Therefore, future research should focus on this issue.

The road to clinical use of high-intensity focused ultrasound for liver cancer: technical and clinical consensus

Clinical use of high-intensity focused ultrasound (HIFU) under ultrasound or MR guidance as a non-invasive method for treating tumors is rapidly increasing. Tens of thousands of patients have been treated for uterine fibroid, benign prostate hyperplasia, bone metastases, or prostate cancer. Despite the methods' clinical potential, the liver is a particularly challenging organ for HIFU treatment due to the combined effect of respiratory-induced liver motion, partial blocking by the rib cage, and high perfusion/flow. Several technical and clinical solutions have been developed by various groups during the past 15 years to compensate for these problems. A review of current unmet clinical needs is given here, as well as a consensus from a panel of experts about technical and clinical requirements for upcoming pilot and pivotal studies in order to accelerate the development and adoption of focused ultrasound for the treatment of primary and secondary liver cancer.

Tumour growth stimulation following partial hepatectomy in mice is associated with increased upregulation of c-Met

Hepatic resection is the preferred option for curative treatment of colorectal liver metastasis (CLM). However, this is associated with significant recurrence rates in both hepatic and extrahepatic sites. The upregulation of growth factors required for liver regeneration after resection is thought to stimulate the growth of micrometastases. The current study describes temporal changes in the expression of hepatocyte growth factor receptor (c-Met), epidermal growth factor receptor (EGFR) and insulin growth factor I receptor (IGF-IR) in an orthotopic mouse model of liver resection and tumour induction. Mice underwent 70% hepatectomy and induction of liver metastases through intrasplenic injection of colorectal cancer cells. Control groups included sham-operated mice and 70% hepatectomy alone. The expression levels of liver and tumour c-Met, EGFR and IGF-IR were quantified by quantitative RT-PCR at different time points. 70% liver resection stimulates tumour growth; increases the expression of c-Met within established tumours and surrounding liver parenchyma; downregulates EGFR expression and increases IGF-IR expression within the liver parenchyma. In conclusion, we demonstrate in our mouse model that major hepatectomy stimulates engraftment and growth of CLM and that this effect is probably due to the upregulation of c-Met as a result of the liver regeneration process. Liver IGF-IR may also contribute to this phenomenon through a paracrine effect on tumour growth. This study provides support for the role of c-Met in the stimulation of tumour growth after resection possibly through the promotion of tumour cell proliferation.

A systematic review of two-stage hepatectomy in patients with initially unresectable colorectal liver metastases

OBJECTIVES

Selected patients with unresectable colorectal liver metastases (CLM) may be rendered resectable using the two-stage hepatectomy (TSH) approach. This review was conducted with the aim of collating and evaluating published evidence for TSH in patients with initially unresectable CLM.

METHODS

Searches of the MEDLINE and EMBASE databases were undertaken to identify studies of TSH in patients with initially unresectable CLM. Studies were required to focus on the perioperative treatment regimen, operative strategy, morbidity, technical success and survival outcomes.

RESULTS

Ten observational studies were reviewed. A total of 459 patients with initially unresectable CLM were selected for the first stage of TSH. Preoperative chemotherapy was used in 88% of patients and achieved partial and stable response rates of 59% and 39%, respectively. Postoperative morbidity and mortality after the first stage of TSH were 17% and 0.5%, respectively. Portal vein embolization (PVE) was used in 76% of patients. Ultimately, 352 of the initial 459 (77%) patients underwent the second stage of TSH. Major liver resection was undertaken in 84% of patients; the negative margin (R0) resection rate was 75%. Postoperative morbidity and mortality after the second stage of TSH were 40% and 3%, respectively. Median overall survival was 37 months (range: 24-44 months) in patients who completed both stages of TSH. In patients who did not complete both stages of TSH, median survival was 16 months (range: 10-29 months). The 3-year disease-free survival rate was 20% (range: 6-27%).

CONCLUSIONS

Two-stage hepatectomy is safe and effective in selected patients with initially unresectable CLM. Further studies are required to better define patient selection criteria for TSH and the exact roles of PVE and preoperative and interval chemotherapy.

A systematic review of two-stage hepatectomy in patients with initially unresectable colorectal liver metastases

OBJECTIVES

Selected patients with unresectable colorectal liver metastases (CLM) may be rendered resectable using the two-stage hepatectomy (TSH) approach. This review was conducted with the aim of collating and evaluating published evidence for TSH in patients with initially unresectable CLM.

METHODS

Searches of the MEDLINE and EMBASE databases were undertaken to identify studies of TSH in patients with initially unresectable CLM. Studies were required to focus on the perioperative treatment regimen, operative strategy, morbidity, technical success and survival outcomes.

RESULTS

Ten observational studies were reviewed. A total of 459 patients with initially unresectable CLM were selected for the first stage of TSH. Preoperative chemotherapy was used in 88% of patients and achieved partial and stable response rates of 59% and 39%, respectively. Postoperative morbidity and mortality after the first stage of TSH were 17% and 0.5%, respectively. Portal vein embolization (PVE) was used in 76% of patients. Ultimately, 352 of the initial 459 (77%) patients underwent the second stage of TSH. Major liver resection was undertaken in 84% of patients; the negative margin (R0) resection rate was 75%. Postoperative morbidity and mortality after the second stage of TSH were 40% and 3%, respectively. Median overall survival was 37 months (range: 24-44 months) in patients who completed both stages of TSH. In patients who did not complete both stages of TSH, median survival was 16 months (range: 10-29 months). The 3-year disease-free survival rate was 20% (range: 6-27%).

CONCLUSIONS

Two-stage hepatectomy is safe and effective in selected patients with initially unresectable CLM. Further studies are required to better define patient selection criteria for TSH and the exact roles of PVE and preoperative and interval chemotherapy.

Tanshinone IIA inhibits metastasis after palliative resection of hepatocellular carcinoma and prolongs survival in part via vascular normalization

Background

Promotion of endothelial normalization restores tumor oxygenation and obstructs tumor cells invasion, intravasation, and metastasis. We therefore investigated whether a vasoactive drug, tanshinone IIA, could inhibit metastasis by inducing vascular normalization after palliative resection (PR) of hepatocellular carcinoma (HCC).

Methods

A liver orthotopic double-tumor xenograft model in nude mouse was established by implantation of HCCLM3 (high metastatic potential) and HepG2 tumor cells. After removal of one tumor by PR, the effects of tanshinone IIA administration on metastasis, tumor vascularization, and survival were evaluated. Tube formation was examined in mouse tumor-derived endothelial cells (TECs) treated with tanshinone IIA.

Results

PR significantly accelerated residual hepatoma metastases. Tanshinone IIA did not inhibit growth of single-xenotransplanted tumors, but it did reduce the occurrence of metastases. Moreover, it inhibited PR-enhanced metastases and, more importantly, prolonged host survival. Tanshinone IIA alleviated residual tumor hypoxia and suppressed epithelial-mesenchymal transition (EMT) in vivo; however, it did not downregulate hypoxia-inducible factor 1α (HIF-1α) or reverse EMT of tumor cells under hypoxic conditions in vitro. Tanshinone IIA directly strengthened tube formation of TECs, associated with vascular endothelial cell growth factor receptor 1/platelet derived growth factor receptor (VEGFR1/PDGFR) upregulation. Although the microvessel density (MVD) of residual tumor tissue increased after PR, the microvessel integrity (MVI) was still low. While tanshinone IIA did not inhibit MVD, it did dramatically increase MVI, leading to vascular normalization.

Conclusions

Our results demonstrate that tanshinone IIA can inhibit the enhanced HCC metastasis associated with PR. Inhibition results from promoting VEGFR1/PDGFR-related vascular normalization. This application demonstrates the potential clinical benefit of preventing postsurgical recurrence.

Low-dose steroid pretreatment ameliorates the transient impairment of liver regeneration

AIM: To determine if liver regeneration (LR) could be disturbed following radiofrequency (RF) ablation and whether modification of LR by steroid administration occurs.

METHODS: Sham operation, partial hepatectomy (PH), and partial hepatectomy with radiofrequency ablation (PHA) were performed on adult Fisher 344 rats. We investigated the recovery of liver volume, DNA synthetic activities, serum cytokine/chemokine levels and signal transducers and activators of transcription 3 DNA-binding activities in the nucleus after the operations. Additionally, the effects of steroid (dexamethasone) pretreatment in the PH group (S-PH) and the PHA group (S-PHA) were compared.

RESULTS: The LR after PHA was impaired, with high serum cytokine/chemokine induction compared to PH, although the ratio of the residual liver weight to body weight was not significantly different. Steroid pretreatment disturbed LR in the S-PH group. On the other hand, low-dose steroid pretreatment improved LR and suppressed tumor necrosis factor (TNF)-α elevation in the S-PHA group, with recovery of STAT3 DNA-binding activity. On the other hand, low-dose steroid pretreatment improved LR and suppressed TNF-α elevation in the S-PHA group, with recovery of STAT3 DNA-binding activity.

CONCLUSION: LR is disturbed after RF ablation, with high serum cytokine/chemokine induction. Low-dose steroid administration can improve LR after RF ablation with TNF-α suppression.

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).

Administration of anti-vascular endothelial growth factor antibody following hepatectomy does not inhibit remnant liver regeneration or growth of remnant metastases

In addition to the use of chemotherapeutic agents for the prevention of multiple liver metastases from colorectal cancer, the anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab, is often used, and its effectiveness has been established. By contrast, it has been reported that the use of bevacizumab prior to or following surgery delays wound healing or liver regeneration. In this study, we investigated whether the administration of bevacizumab following hepatectomy inhibits remnant liver regeneration or the growth of remnant metastases. Mice were partially hepatectomized (31% of the liver was removed), transplanted with the murine colorectal cancer cell line, CT26, in the remnant lobe, and intraperitoneally injected with bevacizumab (4 mg/kg) for a total of 6 times. Serum VEGF levels were measured on day 1 following surgery, and each lobe of the liver was weighed on day 14. Serum VEGF levels in non-hepatectomized, tumor-bearing mice exceeded those in their non-tumor-bearing counterparts; however, the administration of bevacizumab did not reduce the serum VEGF levels. The volume of the liver lobe of the hepatectomized, CT26-transplanted and non-CT26-transplanted mice was 1,349.6 and 735.5 mg, respectively, indicating rapid growth of the CT26 transplant (p=0.023). The volume of the CT26-transplanted lobe of the bevacizumab-administered mice was 1,379.0 mg, which was not significantly different from that (1,349.6 mg) of the non-bevacizumab-administered mice. The volume of the remnant lobe of the bevacizumab-administered mice was 1,051.0 mg, which did not significantly differ from that (957.3 mg) of the non-bevacizumab-administered mice. The administration of bevacizumab following hepatectomy did not delay remnant liver regeneration, and did not suppress the growth of metastases in the remnant lobes or remnant liver regeneration.

Chemotherapy between the first and second stages of a two-stage hepatectomy for colorectal liver metastases: should we routinely recommend it?

BACKGROUND

The aim of the present study is to examine the effect of systemic chemotherapy after the 1st-stage hepatectomy (CT×2) on the progression of disease and dropout rates. A major pitfall of the 2-stage hepatectomy procedure is a high dropout rate after the 1st-stage hepatectomy due to progression of disease (PD). Routine use of CT×2 has been advocated.

METHODS

A total of 47 patients with multiple, bilateral unresectable liver metastases were selected for a 2-stage hepatectomy procedure (±portal vein occlusion).

RESULTS

Of the total, 37 patients (78.7%) underwent systemic chemotherapy before the 1st-stage hepatectomy (CT×1) and 25 patients (53.2%) underwent CT×2; PD was significantly more common during CT×2 than during CT×1 (P=.002). Of the 47 patients planned for the 2nd-stage hepatectomy, 36 (76.6%) completed the procedure. Of these 47 patients, 25 (53.2%) showed PD after the 1st-stage hepatectomy, 12 in the CT×2 group and 13 in the no-CT×2 group; administration of CT×2 did not significantly affect the PD rate (P=.561). The overall dropout rate was 23.4% (n=11 patients): 16% in the CT×2 group vs. 31.8% in the no-CT×2 group (P=.303).

CONCLUSIONS

The routine use of chemotherapy between the 1st- and 2nd-stage hepatectomy does not guarantee lower PD and dropout rates.

Changes in growth factor levels after thermal ablation in a murine model of colorectal liver metastases

OBJECTIVES

This study examines changes in the expression of growth factors following thermal ablation (TA) of selected colorectal cancer (CRC) liver metastases.

METHODS

Using mice with established CRC liver metastases, two tumours in each animal were thermally ablated. Liver and tumour tissues were collected at various time-points (days 0, 1, 2, 3, 5 and 7) following TA treatment from the ablation site and from sites distant from ablated tumour. Changes in growth factor expression (epidermal growth factor [EGF], vascular endothelial growth factor [VEGF], hepatocyte growth factor [HGF] and transforming growth factor-β[TGF-β]) in comparison with baseline levels (non-ablated) were assessed by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry.

RESULTS

Baseline TGF-β and VEGF levels in the liver parenchyma of tumour-bearing mice were significantly higher than levels in naive liver parenchyma. Levels of VEGF and HGF decreased after TA treatment in all tissues. Levels of EGF decreased in ablated and distant tumour tissues, but displayed a tendency to increase in liver tissue. Levels of TGF-β also decreased during the first 2 days following TA, but later increased in liver and tumour tissues distant from the ablation site to a level that reached significance in tumour tissue at day 7 (P < 0.001). Decreases in growth factor levels were also observed in animals that underwent laparotomy without TA treatment, which indicates that these decreases were caused by the experimental procedure.

CONCLUSIONS

Tumour induces upregulation of TGF-β and VEGF in liver parenchyma. Growth factors decreased after TA, but this appears to be the result of the experimental procedure rather than the TA itself. However, TA resulted in increased levels of TGF-β, which may contribute to tumour recurrence.

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.

[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.

Immunoregulatory effects of liver ablation therapies for the treatment of primary and metastatic liver malignancies

Ablation of liver tissue produces in situ tumoural antigens and elicits specific immune responses. The aim of this review is to examine the available data about the local and systemic responses produced and to compare differences between the methods available. A literature search was undertaken for all papers focusing on immune responses following ablative therapy of the liver, including experimental and clinical studies. Following ablative procedures, the cellular response is elicited by the presentation of antigens by dendritic cells to specific CD4(+) T cells, which in turn stimulate natural killer or CD8(+) cytotoxic cells. The local release of intracellular debris activates Kupffer cells to produce cytokines, which, in the immediate vicinity, activate monocytes/macrophages or specific T cells that respond and produce systemic reactions such as fever, thrombocytopaenia or shock. The immune responses elicited by cryotherapy, both cellular and cytokine, seem far greater than those produced by radiofrequency or microwave ablation, probably as a consequence of the peculiar mechanism of cell death of the former (disruptive necrosis). This mechanism is considered central to the pathogenesis of cryoshock. Ablative techniques stimulate the immune system and provide an easy way to achieve in vivo vaccination against tumoural antigens. Immunomodulatory approaches have the potential to augment the initial immune stimulation and this combined approach could pave the way to a more selective and specific method of treating liver tumours.

Influence of approach on outcome in radiofrequency ablation of liver tumors

In this article some recent data concerning the approach on radiofrequency ablation (RFA) of liver tumors are reviewed. Specifically, several critical statements between surgical and percutaneous approach are raised and discussed: (1) Open approach may lead to a higher complication rate; (2) Temporary occlusion of hepatic inflow during surgical approach may lead to a higher rate of ablation of the liver tumors; (3) Surgical approach may permit better targeting of the tumor to be ablated. (4) Surgical approach may discover additional liver tumors. Finally, several conclusions and recommendations are also addressed.

Comparison of hepatic recurrences after resection or intraoperative radiofrequency ablation indicated by size and topographical characteristics of the metastases

AIMS

Intraoperative use of radiofrequency ablation (IRFA) to treat liver metastases is controversial. The aim of this study was to compare local recurrence rate and survival after IRFA versus resection.

METHODS

Three groups from 99 patients were consecutively operated on for 307 liver metastases with 2years of follow up: group 1, IRFA alone (n=34); group 2, IRFA plus resection (n=28); group 3, resection alone (n=37). The choice of IRFA or resection was made on the basis of the sizes and topographies of the metastases with the goal of achieving R0 treatment.

RESULTS

Mortality was zero; morbidity was 9%, 11% and 11% in the three groups respectively. Median follow-up after surgery was 30months. Total hepatic recurrences occurred in 59 (60%) patients. Median survival without hepatic recurrence was 17months with no difference between the three groups (P=0.474). Total local recurrence occurred in 4 (12%) patients in group 1, in 2 (8%) patients in group 2, and in 2 (6%) patients in group 3. Survival at 2years was no different in the three groups.

CONCLUSION

Assessing IRFA indications by size and the topographical characteristics of the liver metastases yields identical local recurrence rates to resection after 2years of follow up.

Radiofrequency ablation versus resection for resectable colorectal liver metastases: time for a randomized trial?

BACKGROUND

Surgical resection is the gold standard in the treatment of resectable colorectal liver metastases (CRLM). In several centers, resection is being replaced by radiofrequency ablation (RFA), even though there is no evidence yet from randomized trials to support this. The aim of this study was to critically review the oncological evidence for and against the use of RFA for resectable CRLM.

METHODS

An exhaustive review of RFA of colorectal metastases was carried out.

RESULTS

Five-year survival data after RFA for resectable CRLM are not available. Percutaneous RFA is associated with worse local control, worse staging, and a small risk of electrode track seeding when compared with resection (level V evidence). For tumors </=3 cm, local control after surgical RFA is equivalent to resection, especially if applied by experienced physicians to nonperivascular tumors (level V evidence). There is indirect evidence for profoundly different biological effects of RFA and resection.

CONCLUSIONS

A subgroup of patients has been identified for whom local control after RFA might be equivalent to resection. Whether this is true, and whether this translates into equivalent survival, remains to be proven. The time has come for a randomized trial.