Colorectal liver metastases

Arterial hypoperfusion as a negative predictive marker for primary hepatic malignancies treated with Y-90 glass microsphere transarterial radioembolization

Background

Radioembolization with yttrium-90 (Y-90) is utilized to treat primary liver malignancies. The efficacy of this intra-arterial therapy in arterially hypoperfused tumors is not known.

Methods

We reviewed data of patients with primary liver tumors treated with Y-90 prescription doses of at least 150 Gy. Baseline patient characteristics, treatment history, imaging-based tumor response assessments, and clinical outcome metrics were recorded. Tumors were classified as arterially hyperperfused versus hypoperfused on post-TARE Y-90 SPECT/CTs or pre-TARE hepatic perfusion SPECT/CTs. Perfusion status was correlated with tumor response assessments and clinical outcomes. Cox proportional hazards models were utilized to compare survival and progression-free survival. Inverse probability weighting was utilized to account for clinical factors and adjusted multivariable proportional hazards analyses to examine the relationship of quantitative perfusion and cancer outcomes.

Results

Of 400 Y-90 treatments, 88 patients received a prescribed dose of at least 150 Gy and had pre- or post-treatment SPECT/CT images. 11 and 77 patients had arterially hypoperfused and hyperperfused lesions, respectively. On dedicated liver MRI or CT at 3 months after Y-90, the complete response rates were 5.6% and 16.5% in the hypoperfused and hyperperfused cohort, respectively (P = 0.60). When controlling for various clinical features, including tumor histology, patients with arterially hypoperfused tumors had significantly shorter progression-free survival (HR 1.87, 95% CI - 1.03 - 3.37, P = 0.039) and greater elsewhere liver (HR 3.36, 95% CI = 1.23 - 9.20, P = 0.019) and distant failure (HR 7.64 (2.71 - 21.54, P < 0.001). In inverse probability weighted analysis, patients with arterially hypoperfused tumors had worse overall survival (P = 0.032). In the quantitative analysis, lower levels of lesion perfusion were also associated with worse clinical outcomes, again controlling for tumor histology.

Conclusion

Compared to arterially hyperperfused tumors, hypoperfused primary liver tumors treated with Y-90 may have worse clinical outcomes.

Open versus laparoscopic liver resection of colorectal metastases: a meta-analysis of matched patient populations

In recent years, the management of colorectal liver metastases (CRLM) has evolved significantly. Laparoscopic liver resection is increasingly being performed, despite a lack of major randomized controlled trial evidence or widespread international consensus. The objective of this review was to compare the short- and long-term outcomes following open and laparoscopic CRLM resection. A systematic review of comparative matched population studies was performed. Evaluated endpoints included surgical outcomes and survival outcomes. Twelve studies were included in this review, reporting on 3095 patients. R0 (negative margins) rates were higher in the laparoscopic CRLM group (89.3% versus 86.9%). In addition, laparoscopic resection was associated with less blood loss (486 mls versus 648 mls, p ≤ 0.0001*) and reduced blood transfusion rates (6.7% vs. 12.2%, OR 2.13, 95% CI 1.08-4.19, p = 0.03*). Major complication rates were higher in the open CRLM group (12.5% vs. 8.1%, OR 1.74, 95% CI 1.30-2.33, p = 0.03*), as was overall hospital length of stay (median 7 versus 5.5 days, p = 0.001*). Perioperative mortality was similar between both groups, and there was no significance in 5-year overall survival for open or laparoscopic CRLM resection groups (58% and 61% respectively). Laparoscopic CRLM resection is associated with less blood loss, lower transfusion rates, major complications, and overall hospital length of stay with comparable oncological outcome.

Identifying enhancement-based staging markers on baseline MRI in patients with colorectal cancer liver metastases undergoing intra-arterial tumor therapy

OBJECTIVES

To determine if three-dimensional whole liver and baseline tumor enhancement features on MRI can serve as staging biomarkers and help predict survival of patients with colorectal cancer liver metastases (CRCLM) more accurately than one-dimensional and non-enhancement-based features.

METHODS

This retrospective study included 88 patients with CRCLM, treated with transarterial chemoembolization or Y90 transarterial radioembolization between 2001 and 2014. Semi-automated segmentations of up to three dominant lesions were performed on pre-treatment MRI to calculate total tumor volume (TTV) and total liver volumes (TLV). Quantitative 3D analysis was performed to calculate enhancing tumor volume (ETV), enhancing tumor burden (ETB, calculated as ETV/TLV), enhancing liver volume (ELV), and enhancing liver burden (ELB, calculated as ELV/TLV). Overall and enhancing tumor diameters were also measured. A modified Kaplan-Meier method was used to determine appropriate cutoff values for each metric. The predictive value of each parameter was assessed by Kaplan-Meier survival curves and univariable and multivariable cox proportional hazard models.

RESULTS

All methods except whole liver (ELB, ELV) and one-dimensional/non-enhancement-based methods were independent predictors of survival. Multivariable analysis showed a HR of 2.1 (95% CI 1.3-3.4, p = 0.004) for enhancing tumor diameter, HR 1.7 (95% CI 1.1-2.8, p = 0.04) for TTV, HR 2.3 (95% CI 1.4-3.9, p < 0.001) for ETV, and HR 2.4 (95% CI 1.4-4.0, p = 0.001) for ETB.

CONCLUSIONS

Tumor enhancement of CRCLM on baseline MRI is strongly associated with patient survival after intra-arterial therapy, suggesting that enhancing tumor volume and enhancing tumor burden are better prognostic indicators than non-enhancement-based and one-dimensional-based markers.

KEY POINTS

• Tumor enhancement of colorectal cancer liver metastases on MRI prior to treatment with intra-arterial therapies is strongly associated with patient survival. • Three-dimensional, enhancement-based imaging biomarkers such as enhancing tumor volume and enhancing tumor burden may serve as the basis of a novel prognostic staging system for patients with liver-dominant colorectal cancer metastases.

p38γ Activation and BGP (Biliary Glycoprotein) Induction in Primates at Risk for Inflammatory Bowel Disease and Colorectal Cancer-A Comparative Study with Humans

Colorectal cancer (CRC) is a common cause of cancer-related deaths largely due to CRC liver metastasis (CRLM). Identification of targetable mechanisms continues and includes investigations into the role of inflammatory pathways. Of interest, MAPK is aberrantly expressed in CRC patients, yet the activation status is not defined. The present study assessed p38γ activation in CRC patients, cancer cells, and tissues of cotton top tamarin (CTT) and common marmoset (CM). The primate world is an overlooked resource as colitis-CRC-prone CTT are usually inure to liver metastasis while CM develop colitis but not CRC. The results demonstrate that p38γ protein and phosphorylation levels are significantly increased in CRC patients compared to normal subjects and CTT. Furthermore, p38γ phosphorylation is significantly elevated in human CRC cells and hepatoblastoma cells but not in CM colon. Additionally, carcinoembryonic antigen (CEA) and biliary glycoprotein (BGP) are induced in the CRC patients that showed p38γ phosphorylation. Inhibition of p38 MAPK in CRC cells showed a significant decline in cell growth with no effect on apoptosis or BGP level. Overall, p38γ is activated in CRC tumorigenesis and likely involves CEA antigens during CRLM in humans but not in the CTT or CM, that rarely develop CRLM.

Quantitative Imaging Biomarkers for 90Y Distribution on Bremsstrahlung SPECT After Resin-Based Radioembolization

Our purpose was to identify baseline imaging features in patients with liver cancer that correlate with ⁹⁰Y distribution on postprocedural SPECT and predict tumor response to transarterial radioembolization (TARE). Methods: This retrospective study was approved by the institutional review board and included 38 patients with hepatocellular carcinoma (HCC) (n = 23; 18/23 men; mean age, 62.39 ± 8.62 y; 34 dominant tumors) and non-HCC hepatic malignancies (n = 15; 9/15 men; mean age, 61.13 ± 11.51 y; 24 dominant tumors) who underwent 40 resin-based TARE treatments (August 2012 to January 2018). Multiphasic contrast-enhanced MRI or CT was obtained before and Bremsstrahlung SPECT within 2 h after TARE. Total tumor volume (cm³) and enhancing tumor volume (ETV [cm³] and % of total tumor volume), and total and enhancing tumor burden (%), were volumetrically assessed on baseline imaging. Up to 2 dominant tumors per treated lobe were analyzed. After multimodal image registration of baseline imaging and SPECT/CT, ⁹⁰Y distribution was quantified on SPECT as tumor-to-normal-liver ratio (TNR). Response was assessed according to RECIST1.1 and quantitative European Association for the Study of the Liver criteria. Clinical parameters were also assessed. Statistical tests included Mann-Whitney U, Pearson correlation, and linear regression. Results: In HCC patients, high baseline ETV% significantly correlated with high TNR on SPECT, demonstrating greater ⁹⁰Y uptake in the tumor relative to the liver parenchyma (P < 0.001). In non-HCC patients, a correlation between ETV% and TNR was observed as well (P = 0.039). Follow-up imaging for response assessments within 1-4 mo after TARE was available for 23 patients with 25 treatments. The change of ETV% significantly correlated with TNR in HCC (P = 0.039) but not in non-HCC patients (P = 0.886). Additionally, Child-Pugh class B patients demonstrated significantly more ⁹⁰Y deposition in nontumorous liver than Child-Pugh A patients (P = 0.021). Conclusion: This study identified ETV% as a quantifiable imaging biomarker on preprocedural MRI and CT to predict ⁹⁰Y distribution on postprocedural SPECT in HCC and non-HCC. However, the relationship between the preferential uptake of ⁹⁰Y to the tumor and tumor response after radioembolization could be validated only for HCC.

Gadoxetic acid-enhanced magnetic resonance imaging significantly influences the clinical course in patients with colorectal liver metastases

Background

Gadoxetic acid (Primovist™)-enhanced magnetic resonance imaging (P-MRI) scans have higher accuracy and increased detection of small colorectal liver metastases (CRLM) compared to CT scans or conventional MRI scans. But, P-MRI scans are still inconsistently acquired in the diagnostic work up of patients with CRLM. The aim of this study was to determine the influence of P-MRI scans on treatment plan proposition and subsequently the clinical course of the patient.

Methods

Eighty-three consecutive patients with potentially resectable CRLM based on a conventional CT scan underwent P-MRI scanning prior to treatment. Treatment plans proposed by the multidisciplinary team were compared before and after P-MRI scanning and related to the final treatment and diagnosis, the accuracy for the CT scan and P-MRI scan was calculated.

Results

P-MRI scans led to a change of treatment in 15 patients (18%) and alteration of extensiveness of local therapy in another 17 patients (20%). All changes were justified leading to an accuracy of 93% for treatment proposition based on P-MRI scan, compared to an accuracy of 75% for the CT scan.

Conclusions

P-MRI scans provide additional information that can aid in proposing the most suitable treatment for patients with CRLM and might prevent short-term reintervention.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0289-x) contains supplementary material, which is available to authorized users.

The impact of liver resection on the dihydrouracil:uracil plasma ratio in patients with colorectal liver metastases

PURPOSE

The dihydrouracil (DHU):uracil (U) plasma ratio is a promising marker for identification of dihydropyrimidine dehydrogenase (DPD)-deficient patients. The objective of this study was to determine the effect of liver resection on the DHU:U plasma ratio in patients with colorectal liver metastases (CRLM).

METHODS

An observational study was performed in which DHU:U plasma ratios in patients with CRLM were analyzed prior to and 1 day after liver resection. In addition, the DHU:U plasma ratio was quantified in six additional patients 4-8 weeks after liver resection to explore long-term effects on the DHU:U plasma ratio. Quantification of U and DHU plasma levels was performed using a validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) assay.

RESULTS

The median (range) DHU:U plasma ratio in 15 patients prior to liver resection was 10.7 (2.6-14.4) and was significantly reduced to 5.5 (< quantification limit (LLOQ-10.5) 1 day after resection (p = 0.0026). This reduction was caused by a decrease in DHU plasma levels from 112.0 (79.8-153) ng/mL to 41.2 (< LLOQ-160) ng/mL 1 day after resection (p = 0.0004). Recovery of the DHU:U plasma ratio occurred 4-8 weeks after liver resection, which was shown by a median (range) DHU:U plasma ratio in six patients of 9.1 (6.9-14.5).

CONCLUSION

Liver resection leads to very low DHU:U plasma ratios 1 day after liver resection, which is possibly caused by a reduction in DPD activity. Quantification of the DHU:U plasma ratios directly after liver resection could lead to false-positive identification of DPD deficiency and is therefore not advised.

Oncogenic function of angiopoietin-2 in vitro and its modulation of tumor progression in colorectal carcinoma

Angiopoietin-2 (Ang-2) has been investigated in cancer primarily in terms of its angiogenic function, and its role as an oncogene has yet to be elucidated. The current study hypothesized that Ang-2 may be an oncogene and have a function in tumor progression. An investigation of the function of Ang-2 in the LoVo colorectal cancer (CRC) cell line in vitro, which expresses a high level of Ang-2, was performed by knocking down endogenous expression with a targeted short hairpin RNA. The aggressive phenotypic effects of Ang-2 on experimental and control group cells were assessed using cell proliferation, migration and invasion assays. The association between Ang-2 expression levels and clinicopathological factors was evaluated in 415 CRC tissues using immunohistochemistry. Suppressing Ang-2 expression decreased cellular proliferation, invasion and migration in an in vitro study. Ang-2 overexpression was observed in 46% of patients with CRC and was significantly associated with pT (P=0.048), pN (P<0.001), venous invasion (P=0.023), lymphatic invasion (P<0.001) and tumor-node-metastasis stage (P=0.022). Furthermore, Ang-2 overexpression was an independent prognostic factor in pN stages 1 and 2. These results reveal that Ang-2 may be an oncogene in colorectal carcinogenesis and its expression may exert aggressive phenotypic effects during tumor progression. In addition, Ang-2 expression may serve as a prognostic marker and a potential drug target.

Stereotactic body radiation therapy for liver oligo-recurrence and oligo-progression from various tumors

Purpose

To evaluate the outcomes of stereotactic body radiation therapy (SBRT) for patients with liver oligo-recurrence and oligo-progression from various primary tumors.

Materials and Methods

Between 2002 and 2013, 72 patients with liver oligo-recurrence (oligo-metastasis with a controlled primary tumor) and oligo-progression (contradictory progression of a few sites of disease despite an overall tumor burden response to therapy) underwent SBRT. Of these, 9 and 8 patients with uncontrollable distant metastases and patients immediate loss to follow-up, respectively, were excluded. The total planning target volume was used to select the SBRT dose (median, 48 Gy; range, 30 to 60 Gy, 3–4 fractions). Toxicity was evaluated using the Common Toxicity Criteria for Adverse Events v4.0.

Results

We evaluated 55 patients (77 lesions) treated with SBRT for liver metastases. All patients had controlled primary lesions, and 28 patients had stable lesions at another site (oligo-progression). The most common primary site was the colon (36 patients), followed by the stomach (6 patients) and other sites (13 patients). The 2-year local control and progression-free survival rates were 68% and 22%, respectively. The 2- and 5-year overall survival rates were 56% and 20%, respectively. The most common adverse events were grade 1–2 fatigue, nausea, and vomiting; no grade ≥3 toxicities were observed. Univariate analysis revealed that oligo-progression associated with poor survival.

Conclusion

SBRT for liver oligo-recurrence and oligo-progression appears safe, with similar local control rates. For liver oligo-progression, criteria are needed to select patients in whom improved overall survival can be expected through SBRT.

Enhanced colorectal cancer metastases in the alcohol-injured liver

Metastatic liver disease is a major cause of mortality in colorectal cancer (CRC) patients. Alcohol consumption is a noted risk factor for secondary cancers yet the role of alcoholic liver disease (ALD) in colorectal liver metastases (CRLM) is not defined. This work evaluated tumor cell colonization in the alcoholic host liver using a novel preclinical model of human CRC liver metastases. Immunocompromised Rag1-deficient mice were fed either ethanol (E) or isocaloric control (C) diets for 4 weeks prior to intrasplenic injection of LS174T human CRC cells. ALD and CRLM were evaluated 3 or 5 weeks post-LS174T cell injection with continued C/E diet administration. ALD was confirmed by increased serum transaminases, hepatic steatosis and expression of cytochrome P4502E1, a major ethanol-metabolizing enzyme. Alcohol-mediated liver dysfunction was validated by impaired endocytosis of asialoorosomucoid and carcinoembryonic antigen (CEA), indicators of hepatocellular injury and progressive CRC disease, respectively. Strikingly, the rate and burden of CRLM was distinctly enhanced in alcoholic livers with metastases observed earlier and more severely in E-fed mice. Further, alcohol-related increases (1.5-3.0 fold) were observed in the expression of hepatic cytokines (TNF-α, IL-1 beta, IL-6, IL-10) and other factors noted to be involved in the colonization of CRC cells including ICAM-1, CCL-2, CCL-7, MMP-2, and MMP-9. Also, alcoholic liver injury was associated with altered hepatic localization as well as increased circulating levels of CEA released from CRC cells. Altogether, these findings indicate that the alcoholic liver provides a permissive environment for the establishment of CRLM, possibly through CEA-related inflammatory mechanisms.

Improved Visibility of Metastatic Disease in the Liver During Intra-Arterial Therapy Using Delayed Arterial Phase Cone-Beam CT

Purpose

To compare the visibility of liver metastases on dual-phase cone-beam CT (DP-CBCT) and digital subtraction angiography (DSA), with reference to preinterventional contrast-enhanced magnetic resonance imaging (CE-MRI) of the liver.

Methods

This IRB-approved, retrospective study included 28 patients with neuroendocrine (NELM), colorectal (CRCLM), or sarcoma (SLM) liver metastases who underwent DP-CBCT during intra-arterial therapy (IAT) between 01/2010 and 10/2014. DP-CBCT was acquired after a single contrast agent injection in the tumor-feeding arteries at early and delayed arterial phases (EAP and DAP). The visibility of each lesion was graded by two radiologists in consensus on a three-rank scale (complete, partial, none) on DP-CBCT and DSA images using CE-MRI as reference.

Results

47 NELM, 43 CRCLM, and 16 SLM were included. On DSA 85.1, 44.1, and 37.5 % of NELM, CRCLM, and SLM, were at least partially depicted, respectively. EAP-CBCT yielded significantly higher sensitivities of 88.3 and 87.5 % for CRCLM and SLM, respectively (p < 0.01), but not for NELM (89.4 %; p = 1.0). On DAP-CBCT all NELM, CRCLM, and SLM were visible (p < 0.001). Complete depiction was achieved on DSA for 59.6, 16.3, and 18.8 % of NELM, CRCLM, and SLM, respectively. The complete depiction rate on EAP-CBCT was significantly higher for CRCLM (46.5 %; p < 0.001), lower for NELM (40.4 %; p = 0.592), and similar for SLM (25 %, p = 0.399). On DAP-CBCT however, the highest rates of complete depiction were found—NELM (97.8 %; p = 0.008), CRCLM (95.3 %; p = 0.008), and SLM (100 %; p < 0.001).

Conclusion

DAP-CBCT substantially improved the visibility of liver metastases during IAT. Future studies need to evaluate the clinical impact.

Liver Resection for Non-Colorectal Liver Metastases - Standards and Extended Indications

Background

Due to the uncertain benefit of liver resection for non-colorectal liver metastases (NCLM), patient selection for surgery is generally difficult. Therefore, the aim of this article was to propose standard and extended indications for liver resection in this heterogeneous disease collective.

Methods

Review of the literature.

Results

The myriad of biologically different primary tumor entities as well as the mostly small and retrospective studies investigating the benefit of surgery for NCLM limits the proposal of general recommendations. Only resection of neuroendocrine liver metastases (NELM) appears to offer a clear benefit with a 5- and 10-year overall survival (OS) of 74 and 51%, respectively, in the largest series. Resection of liver metastases from genitourinary primaries might offer reasonable benefit in selected cases – with a 5-year OS of up to 61% for breast cancer and of 38% for renal cell cancer. The long-term outcome following surgery for other entities was remarkably poorer, e.g., gastric cancer, pancreatic cancer, and melanoma reached a 5-year OS of 20-42, 17-25, and about 20%, respectively.

Conclusion

Liver resection for NELM can be defined as a standard indication for the resection of NCLM while lesions of genitourinary origin might be defined as an extended indication.

Early survival prediction after intra-arterial therapies: a 3D quantitative MRI assessment of tumour response after TACE or radioembolization of colorectal cancer metastases to the liver

OBJECTIVES

This study evaluated the predictive role of 1D, 2D and 3D quantitative, enhancement-based MRI regarding overall survival (OS) in patients with colorectal liver metastases (CLM) following intra-arterial therapies (IAT).

METHODS

This retrospective analysis included 29 patients who underwent transarterial chemoembolization (TACE) or radioembolization and received MRI within 6 weeks after therapy. Tumour response was assessed using 1D and 2D criteria (such as European Association for the Study of the Liver guidelines [EASL] and modified Response Evaluation Criteria in Solid Tumors [mRECIST]). In addition, a segmentation-based 3D quantification of overall (volumetric [v] RECIST) and enhancing lesion volume (quantitative [q] EASL) was performed on portal venous phase MRI. Accordingly, patients were classified as responders (R) and non-responders (NR). Survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios (HR).

RESULTS

Only enhancement-based criteria identified patients as responders. EASL and mRECIST did not predict patient survival (P = 0.27 and P = 0.44, respectively). Using uni- and multivariate analysis, qEASL was identified as the sole predictor of patient survival (9.9 months for R, 6.9 months for NR; P = 0.038; HR 0.4).

CONCLUSION

The ability of qEASL to predict survival early after IAT provides evidence for potential advantages of 3D quantitative tumour analysis.

KEY POINTS

• Volumetric assessment of colorectal liver metastases after intra-arterial therapy is feasible. • Early 3D quantitative tumour analysis after intra-arterial therapy may predict patient survival. • Volumetric tumour response assessment shows advantages over 1D and 2D techniques. • Enhancement-based MR response assessment is preferable to size-based measurements.

Observer Performance in the Detection and Classification of Malignant Hepatic Nodules and Masses with CT Image-Space Denoising and Iterative Reconstruction

PURPOSE

To determine if lower-dose computed tomographic (CT) scans obtained with adaptive image-based noise reduction (adaptive nonlocal means [ANLM]) or iterative reconstruction (sinogram-affirmed iterative reconstruction [SAFIRE]) result in reduced observer performance in the detection of malignant hepatic nodules and masses compared with routine-dose scans obtained with filtered back projection (FBP).

MATERIALS AND METHODS

This study was approved by the institutional review board and was compliant with HIPAA. Informed consent was obtained from patients for the retrospective use of medical records for research purposes. CT projection data from 33 abdominal and 27 liver or pancreas CT examinations were collected (median volume CT dose index, 13.8 and 24.0 mGy, respectively). Hepatic malignancy was defined by progression or regression or with histopathologic findings. Lower-dose data were created by using a validated noise insertion method (10.4 mGy for abdominal CT and 14.6 mGy for liver or pancreas CT) and images reconstructed with FBP, ANLM, and SAFIRE. Four readers evaluated routine-dose FBP images and all lower-dose images, circumscribing liver lesions and selecting diagnosis. The jackknife free-response receiver operating characteristic figure of merit (FOM) was calculated on a per-malignant nodule or per-mass basis. Noninferiority was defined by the lower limit of the 95% confidence interval (CI) of the difference between lower-dose and routine-dose FOMs being less than -0.10.

RESULTS

Twenty-nine patients had 62 malignant hepatic nodules and masses. Estimated FOM differences between lower-dose FBP and lower-dose ANLM versus routine-dose FBP were noninferior (difference: -0.041 [95% CI: -0.090, 0.009] and -0.003 [95% CI: -0.052, 0.047], respectively). In patients with dedicated liver scans, lower-dose ANLM images were noninferior (difference: +0.015 [95% CI: -0.077, 0.106]), whereas lower-dose FBP images were not (difference -0.049 [95% CI: -0.140, 0.043]). In 37 patients with SAFIRE reconstructions, the three lower-dose alternatives were found to be noninferior to the routine-dose FBP.

CONCLUSION

At moderate levels of dose reduction, lower-dose FBP images without ANLM or SAFIRE were noninferior to routine-dose images for abdominal CT but not for liver or pancreas CT.

Repeat hepatic resection in patients with colorectal liver metastases

AIM: To investigate the survival outcomes of secondary hepatectomy for recurrent colorectal liver metastases (CRLM).

METHODS: From October 1994 to December 2009, patients with CRLM who underwent surgical treatment with curative intent were investigated. Patients were divided into two groups: patients who underwent primary hepatectomy (Group 1) and those who underwent secondary hepatectomy for recurrent CRLM (Group 2).

RESULTS: Survival and prognostic factors were analyzed. A total of 461 patients were included: 406 patients in Group 1 and 55 patients in Group 2. After a median 39-mo (range, 3-195 mo) follow-up, there was a significant difference between Groups 1 and 2 in terms of disease-free survival (P = 0.029) although there was no significant difference in overall survival (P = 0.206). Secondary hepatectomy was less effective in patients with multiple recurrent CRLM than primary hepatectomy for initial CRLM (P = 0.008). Multiple CRLM and radiofrequency ablation therapy were poor prognostic factors of secondary hepatectomy in multivariate Cox regression analysis (P = 0.006, P = 0.004, respectively).

CONCLUSION: Secondary hepatectomy for single recurrent CRLM is as effective as primary surgical treatment for single recurrent CRLM. However, secondary hepatectomy for multiple recurrent CRLM is less effective than that for single recurrent CRLM.

Colorectal hepatic metastasis: Evolving therapies

The approach for colorectal hepatic metastasis has advanced tremendously over the past decade. Multidrug chemotherapy regimens have been successfully introduced with improved outcomes. Concurrently, adjunct multimodal therapies have improved survival rates, and increased the number of patients eligible for curative liver resection. Herein, we described major advancements of surgical and oncologic management of such lesions, thereby discussing modern chemotherapeutic regimens, adjunct therapies and surgical aspects of liver resection.

Six-year experience of a nurse-led colorectal cancer follow-up clinic

Aims and Objectives. To review the experience of a nurse-led colorectal cancer follow-up clinic in a tertiary referral colorectal cancer centre. Methodology. Data from the nurse-led colorectal cancer follow-up clinic in our unit was prospectively maintained in a colorectal cancer database. Data was analysed from January 1, 2006 until the December 31, 2011. Results. 1125 patients were diagnosed with colorectal cancer, and referred to our unit as a tertiary centre for specialised colorectal cancer. Nine hundred and four patients had surgical resection of their colorectal cancer. Four hundred and seven patients were referred to the nurse-led colorectal cancer clinic for surveillance. The mean age of the patient cohort was 67 years (range 32-88) and 56% of patients were male. One hundred and seventeen patients were discharged to their general practitioner having been disease free after 5 years of followup. Fifty-four patients were diagnosed with either local or distant recurrence. Conclusion. A nurse-led colorectal cancer follow-up clinic is running according to strict follow-up protocols. This type of clinic significantly reduces the number of routine follow-up patients that have to be seen by the colorectal surgical consultant.

Treatment of metastatic liver tumors using stereotactic ablative radiotherapy

The prognosis of patients with metastatic liver disease remains dismal with a median survival of only 6-12 mo. As 80%-90% of patients are not candidates for surgical therapy, there is a need for effective non-surgical therapies that would improve outcomes in these patients. The body of evidence related to the use of stereotactic ablative radiotherapy (SABR) in metastatic liver disease has substantially grown and evolved over the past decade. This review summarizes the current evidence supporting liver SABR with particular attention given to patient selection, target delineation, organ at risk dose volume constraints, response evaluation imaging and the various SABR techniques for delivering ablative radiotherapy to the liver. Even though it is unclear what dose-fractionation scheme, delivery system, concomitant therapy or patient selection strategy yields the optimum liver SABR outcomes, clear and growing evidence is available that SABR is a safe and effective therapy for the treatment of oligometastatic liver disease.

Current approaches and challenges for monitoring treatment response in colon and rectal cancer

Introduction: With the advent of multidisciplinary and multimodality approaches to the management of colorectal cancer patients, there is an increasing need to define how we monitor response to novel therapies in these patients. Several factors ranging from the type of therapy used to the intrinsic biology of the tumor play a role in tumor response. All of these can aid in determining the ideal course of treatment, and may fluctuate over time, pending down-staging or progression of disease. Therefore, monitoring how disease responds to therapy requires standardization in order to ultimately optimize patient outcomes. Unfortunately, how best to do this remains a topic of debate among oncologists, pathologists, and colorectal surgeons. There may not be one single best approach. The goal of the present article is to shed some light on current approaches and challenges to monitoring treatment response for colorectal cancer.

Methods: A literature search was conducted utilizing PubMed and the OVID library. Key-word combinations included colorectal cancer metastases, neoadjuvant therapy, rectal cancer, imaging modalities, CEA, down-staging, tumor response, and biomarkers. Directed searches of the embedded references from the primary articles were also performed in selected circumstances.

Results: Pathologic examination of the post-treatment surgical specimen is the gold standard for monitoring response to therapy. Endoscopy is useful for evaluating local recurrence, but not in assessing tumor response outside of the limited information gained by direct examination of intra-lumenal lesions. Imaging is used to monitor tumors throughout the body for response, with CT, PET, and MRI employed in different circumstances. Overall, each has been validated in the monitoring of patients with colorectal cancer and residual tumors.

Conclusion: Although there is no imaging or serum test to precisely correlate with a tumor's response to chemo- or radiation therapy, these modalities, when used in combination, can aid in allowing clinicians to adjust medical therapy, pursue operative intervention, or (in select cases) identify complete responders. Improvements are needed, however, as advances across multiple modalities could allow appropriate selection of patients for a close surveillance regimen in the absence of operative intervention.

PTB-associated splicing factor (PSF) is a PPARγ-binding protein and growth regulator of colon cancer cells

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor that plays an essential role in cell proliferation, apoptosis, and inflammation. It is over-expressed in many types of cancer, including colon, stomach, breast, and lung cancer, suggesting that regulation of PPARγ might affect cancer pathogenesis. Here, using a proteomic approach, we identify PTB-associated splicing factor (PSF) as a novel PPARγ-interacting protein and demonstrate that PSF is involved in several important regulatory steps of colon cancer cell proliferation. To investigate the relationship between PSF and PPARγ in colon cancer, we evaluated the effects of PSF expression in DLD-1 and HT-29 colon cancer cell lines, which express low and high levels of PPARγ, respectively PSF affected the ability of PPARγ to bind, and expression of PSF siRNA significantly suppressed the proliferation of colon cancer cells. Furthermore, PSF knockdown induced apoptosis via activation of caspase-3. Interestingly, DLD-1 cells were more susceptible to PSF knockdown-induced cell death than HT-29 cells. Our data suggest that PSF is an important regulator of cell death that plays critical roles in the survival and growth of colon cancer cells. The PSF-PPARγ axis may play a role in the control of colorectal carcinogenesis. Taken together, this study is the first to describe the effects of PSF on cell proliferation, tumor growth, and cell signaling associated with PPARγ.

A meta-analysis comparing simultaneous versus delayed resections in patients with synchronous colorectal liver metastases

INTRODUCTION

The traditional surgical management for patients presenting with synchronous colorectal liver metastases (SCLM) has been a delayed resection. However, in some centres, there has been a shift in favour of 'simultaneous' resections. The aim of this study was to use a meta-analytical model to compare the short-term and long-term outcomes in patients with synchronous colorectal liver metastases (SCLM) undergoing simultaneous resections versus delayed resections.

METHOD

Comparative studies published between 1991 and 2010 were included. Evaluated endpoints were intra-operative parameters, post-operative parameters, post-operative adverse events and survival. A random-effects meta-analytical model was used and sensitivity analysis performed to account for bias in patient selection.

RESULTS

Twenty-four non-randomized studies were included, reporting on 3159 patients of which 1381 (43.7%) had simultaneous resections and 1778 (56.3%) had delayed resections. The bilobar distribution (P = 0.01), size of liver metastases (P < 0.001) and the proportion of major liver resections (P < 0.001) was found to be higher in the delayed resection group compared to the simultaneous resection group. There was no significant difference in operative blood loss (95% CI, -279.28, 22.53; P = 0.1) or duration of surgery (WMD -23.83, 95% CI, -85.04, 37.38; P = 0.45). Duration of hospital stay was significantly reduced in simultaneous resections by 5.6 days (95% CI: 2.4-8.9 days, P = 0.007) No significant differences in post-operative complications (36% vs 37%, P = 0.27), overall survival (HR 1.00, 95% CI 0.86-1.15, P = 0.96) or disease free survival (HR 0.85, 95% CI 0.71-1.02, P = 0.08) were found. Sensitivity analysis revealed that these findings were consistent for the duration of hospital stay, post-operative complications, overall survival and disease free survival.

CONCLUSION

This study demonstrates that the selection criteria for patients undergoing simultaneous or delayed resections differs resulting in a discrepancy in the metastatic disease severity being compared between the two groups. The comparable intra-operative parameters, post-operative complications and survival found between the two groups suggest that delayed resections may result in better outcomes. Similarly, the reduced length of hospital stay in simultaneous resections may only be as a result of the reduced disease severity in this group. Simultaneous resections can only be recommended in patients with limited hepatic disease until prospective studies comparing similar disease burdens between the two resection groups are available.

The tumour biology of synchronous and metachronous colorectal liver metastases: a systematic review

Forty to fifty percent of colorectal cancer (CRC) patients develop colorectal liver metastases (CLM) that are either synchronous or metachronous in presentation. Clarifying whether there is a biological difference between the two groups of liver metastases or their primaries could have important clinical implications. A systematic review was performed using the following resources: MEDLINE from PubMed (1950 to present), Embase, Cochrane and the Web of Knowledge. Thirty-one articles met the inclusion criteria. The review demonstrated that the majority of studies found differences in molecular marker expression between colorectal liver metastases and their respective primaries in both the synchronous and metachronous groups. Studies investigating genetic aberrations demonstrated that the majority of changes in the primary tumour were 'maintained' in the colorectal liver metastases. A limited number of studies compared the primary tumours of the synchronous and metachronous groups and generally demonstrated no differences in marker expression. Although there were conflicting results, the colorectal liver metastases in the synchronous and metachronous groups demonstrated some differences in keeping with a more aggressive tumour subtype in the synchronous group. This review suggests that biological differences may exist between the liver metastases of the synchronous and metachronous groups. Whether there are biological differences between the primaries of the synchronous and metachronous groups remains undetermined due to the limited number of studies available. Future research is required to determine whether differences exist between the two groups and should include comparisons of the primary tumours.