Chemotherapy permits resection of metastatic colorectal cancer: experience from Intergroup N9741

Conversion therapy with pembrolizumab for a peritoneal metastasis of rectal cancer causing hydronephrosis in a patient with Lynch syndrome

A 44-year-old woman with Lynch syndrome was referred to our hospital for treatment of recurrence of microsatellite instability-high rectal cancer. [18F]Fluorodeoxyglucose (18FDG)-positron emission tomography revealed a peritoneal metastasis with invasion to the small intestine and left ureter. The peritoneal metastasis was diagnosed initially as unresectable because of extensive invasion to the left ureter requiring nephrectomy. Hence, first-line treatment with pembrolizumab was started. After the first course of pembrolizumab, she developed hydronephrosis and a resulting urinary tract infection (UTI). A percutaneous nephrostomy was performed to control the UTI. After six courses of pembrolizumab, 18FDG-positron emission tomography showed that the peritoneal metastasis was smaller with significantly reduced 18FDG uptake, and it was then diagnosed as resectable without nephrectomy. She underwent R0 resection of the peritoneal metastasis with partial resection of the small intestine. Intraoperatively, the peritoneal metastasis showed no invasion of the left ureter, allowing its preservation. The percutaneous nephrostomy was removed postoperatively, and she has not developed any subsequent UTIs. Histopathologically, the tumor showed a pathological complete response to pembrolizumab. To the best of our knowledge, this is the first case of conversion therapy with pembrolizumab for peritoneal metastasis with hydronephrosis.

Radiological complete response with regorafenib for multiple lung metastases of ascending colon cancer: a case report

BACKGROUND

Regorafenib is an oral diphenylurea multikinase inhibitor and currently approved for use following third-line therapy for metastatic colorectal cancer (CRC) patients. Only one case has previously been reported of metastatic CRC showing a complete response (CR) to regorafenib.

CASE PRESENTATION

A 68-year-old Japanese man underwent laparoscopy-assisted ileocecal resection and D3 lymphadenectomy due to his ascending colon cancer. Eighteen months after surgery, a laparoscopic hepatic left lateral segmentectomy was performed due to a liver tumor, and a pathological diagnosis of colorectal liver metastasis was made. Three months after the second surgery, contrast-enhanced computed tomography (CT) revealed multiple lung metastases. The patient had undergone 18 courses of the FOLFOX + bevacizumab chemotherapy regimen as their first-line therapy and 11 courses of the FOLFIRI + ramucirumab chemotherapy regimen as their second-line therapy. As their third-line therapy, the patient was administered the regorafenib chemotherapy regimen. We evaluated the chemotherapy treatment's effect on the lung tumors by CT after 3, 7, 11, and 17 courses of the regorafenib chemotherapy regimen, finding that the lung tumors had shrunk with time; thus, each tumor was considered a partial response (PR) based on the RECIST guidelines. After 21 courses of the regorafenib chemotherapy regimen, the chemotherapy was discontinued in response to the patient's wishes. Even at 1 and 3 months after the discontinuation of the chemotherapy, CT revealed that the lung tumors had shrunk, with each considered a PR. Furthermore, 9 months after the discontinuation of the chemotherapy, CT revealed scarring of the lung tumors. This was considered a CR, rather than a PR. The patient remains disease-free 18 months after the discontinuation of chemotherapy.

CONCLUSIONS

In this paper, we present the second case of radiological CR with regorafenib for multiple lung metastases of ascending colon cancer. Currently, there is no consensus on a treatment strategy for patients with radiological CR.

Colorectal Liver Metastases: A Literature Review of Viable Surgical Options with a Special Focus on Microwave Liver Thermal Ablation and Mini-Invasive Approach

Colorectal cancer (CRC) is the third most common tumor worldwide and it is characterized in 20-30% of cases by liver involvement, which strongly affects the long-term patient outcome. There are many available therapies for liver colorectal metastases (CRLMs); the current standard of care is represented by liver resection, and when feasible, associated with systemic chemotherapy. Microwave thermal ablation (MWA) is a viable option in unresectable patients or to achieve treatment with a parenchymal spearing approach. A literature review was performed for studies published between January 2000 and July 2022 through a database search using PUBMED/Medline and the Cochrane Collaboration Library with the following MeSH search terms and keywords: microwave, ablation, liver metastases, colorectal neoplasm, and colon liver rectal metastases. The recurrence rate and overall patients' survival were evaluated, showing that laparoscopic MWA is safe and effective to treat CRLMs when resection is not feasible, or a major hepatectomy in fragile patients is necessary. Considering the low morbidity of this procedure, it is a viable option to treat patients with recurrent diseases in the era of effective chemotherapy and multimodal treatments.

Neoadjuvant Versus Adjuvant Chemotherapy for Resectable Metastatic Colon Cancer in Non-academic and Academic Programs

BACKGROUND

Overall survival advantage of chemotherapy before versus after metastasectomy of liver or lung lesion is not clear for colon cancer with synchronous liver or lung metastasis.

MATERIALS AND METHODS

Adults 20 years or older with primary colon cancer and single organ metastatic disease either in the liver or lung at diagnosis were identified between 2010 and 2015 through the National Cancer Database (NCDB). Patients were categorized into 2 cohorts: pre-operative/peri-operative chemotherapy (neoadjuvant -[NAC]) or post-operative chemotherapy (adjuvant [AC]). Survivals and factors associated with were compared between the 2 groups.

RESULTS

A total of 3038 patients with colon cancer with liver or lung metastases were identified. The percentage of patients receiving NAC had steadily increased from 12.29% to 28.31%, mostly in academic programs. On multivariate analysis, patients who received NAC had an overall survival advantage in the non-academic setting whereas no advantage is seen in the patients treated in the academic settings. The median overall survival for patients receiving NAC and AC was 47.24 months and 38.08 months, respectively. Factors associated with overall survival advantage in NAC patients treated in non-academic programs included age 20-49 years, CEA value of >30, right-sided colon primary, liver metastasis, and clear resection margins.

CONCLUSIONS

Metastatic colon cancer with single organ liver or lung lesions benefits from neoadjuvant chemotherapy, especially in -non-academic settings. The overall survival advantage in this setting has not been shown before.

Probiotic Supplementation Suppresses Tumor Growth in an Experimental Colorectal Cancer Liver Metastasis Model

Colorectal cancer (CRC) ranks third in incidence and second in mortality of all cancers worldwide. At the time of primary diagnosis, around 20% of patients already have metastatic CRC and only around 20% are candidates for radical resection. Thus, most of the patients have to undergo chemotherapy (CTx). Due to chemoresistance and side effects, novel treatment additives are crucial for controlling the disease and prolonging patient survival. The aim of this study was to evaluate probiotic supplementation and its antitumorigenic effects in an experimental CRC liver metastasis model. Six-week-old male Wistar rats received either a multispecies probiotic (1.2 × 10⁹ CFU/daily) or placebo mixture. On day 14 of the experiment, rat CRC cells (CC531) were implanted under the liver capsule later treated by FOLFOX CTx. Change in tumor volume was measured by performing micro computed tomography (micro-CT) scanning on experimental days 28 and 34. Additionally, immunohistochemical staining with anti-MPO, anti-Ki67, and anti-CD31 were performed. Tumor apoptosis was evaluated using TUNEL staining. Micro-CT image analysis indicates that probiotic supplementation significantly inhibits tumor growth. No synergistic effects between probiotic supplementation and FOLFOX CTx was observed. Reduced tumor volume was achieved by inhibiting angiogenesis, as tumor microvascular density was significantly lower in rats receiving probiotic supplementation. This study shows that a multispecies probiotic mixture significantly reduces angiogenesis and inhibits CRC liver metastasis growth in an experimental rat model.

Pathological complete response to pembrolizumab in patients with metastatic ascending colon cancer with microsatellite instability

Pembrolizumab is a novel immune-checkpoint inhibitor used for treatment of microsatellite instability-high (MSI-H) colorectal cancer. Several studies have reported clinical complete response (CR) after treatment with pembrolizumab, but none has confirmed pathological CR. Here we provide the first description of pathological CR with R0 resection after immune-checkpoint therapy. A 45-year-old man presented at our hospital with abdominal distention and highly elevated tumor markers. Contrast-enhanced abdominal CT showed a 110 × 75 mm bulky mass with markedly swollen lymph nodes and an isolated peritoneal metastasis in the pelvic space. Biopsy revealed poorly differentiated adenocarcinoma. We diagnosed ascending colon cancer cT4aN2bM1c Stage IVc. A biopsy specimen obtained during systemic chemotherapy (FOLFOXIRI) was confirmed pathologically as MSI-H, after which the treatment was changed to pembrolizumab. The tumor markers rapidly decreased to within normal ranges after three courses of treatment. After twenty courses, CT revealed shrinkage of the main tumor, lymph node metastases, and the peritoneal metastasis, and we performed extended right hemi-colectomy with dissection of the peritoneal metastasis. No residual tumor cells were found histologically. The patient achieved pathological CR and the postoperative course was uneventful. An accurate diagnosis and appropriate follow up are crucial for obtaining sufficient therapeutic effect of pembrolizumab.

Oxidative stress and endoplasmic reticulum stress contribute to L. paracasei subsp. paracasei M5L exopolysaccharide-induced apoptosis in HT-29 cells

Colorectal cancer is the third most malignant cancer occurring around the world. Effective prevention and treatment have been increasingly the focus of global attention. Long-term diet of fermented dairy inhibits proliferation of colon cancer cell, which is considered that not only live lactic acid bacteria but also the secreted exopolysaccharides exert the function. In this scenario, this study aimed to investigate the mechanism of growth inhibition on HT-29 cells induced in vitro by exopolysaccharides isolated from Lactobacillus paracasei subsp. paracasei M5L (M5-EPSs). HT-29 cells which were treated by a set of concentrations of M5-EPSs have been investigated of cell viability, characteristic changes, cell cycle distribution, and redox system. The results demonstrated that M5-EPSs treatments induced HT-29 cell apoptosis and resulted in upregulation of ROS levels and downregulation of antioxidant enzyme activities, leading to an imbalance in the oxidation system in HT-29 cells. In response to M5-EPSs, endogenous ER stress (ERS) markers, including GRP78, ATF4, and CHOP, were transcriptionally altered so that activating the ERS in HT-29 cells. After NAC treatment, the oxidative stress was inhibited, and the expression of GRP78 and CHOP was significantly decreased, indicating that oxidative stress can significantly affect the ERS pathway. Furthermore, it suggested that the occurrence of apoptosis was associated with Bcl-2 gene family. In conclusion, this study demonstrated that M5-EPSs can induce HT-29 cells apoptosis by destroying the redox system through activation of the ERS signaling pathway.

Surgical Management of Colorectal Cancer Liver Metastases

Approximately 50% of colorectal cancer patients develop liver metastases. Hepatic metastases represent the most common cause of colorectal cancer-related mortality. Metastasectomy, if possible, represents the most effective treatment strategy; 20% of patients will be cured and more than 50% survive at least 5 years. Nuances to treatment planning hinge on whether patients present with resectable disease upfront, whether the future liver remnant is adequate, and whether the primary tumor, if present, is colon versus rectal in origin. This article discusses considerations impacting our approach to patients with colorectal liver metastases and the role for various multimodal treatment options.

Perioperative Chemotherapy for Liver Metastasis of Colorectal Cancer

Simple Summary

Survival outcomes for resectable metastatic colorectal cancer have improved over the past decade. This is due in part to improvements made in imaging technology, locoregional treatment, and systemic treatment. The focus of this review is to summarize and analyze the existing information available on systemic therapy in the setting of colorectal cancer with liver metastases. It is written with structured viewpoints including patient selection, sequencing of treatment, choice of systemic therapy for upfront resectable disease and conversion chemotherapy for unresectable colorectal cancer. Post-treatment surveillance and future research directions are also discussed. This review will help treating physicians make decisions for the treatment of liver metastases of colorectal cancer.

Abstract

The liver is the dominant site of metastasis for patients with colorectal cancer. For those with isolated liver metastases, surgical resection with systemic therapy has led to long-term remission in as high as 80% of patients in well-selected cohorts. This review will focus on how systemic therapy should be integrated with resection of liver metastases; in particular, the use of clinical risk scores based on clinicopathological features that help with patient selection, various approaches to the treatment of micro-metastatic disease (peri-operative versus post-operative chemotherapy), as well as conversion chemotherapy for those with initially upfront unresectable disease will be discussed.

Predicting Overall Survival in Patients with Metastatic Rectal Cancer: a Machine Learning Approach

BACKGROUND

A significant proportion of patients with rectal cancer will present with synchronous metastasis at the time of diagnosis. Overall survival (OS) for these patients are highly variable and previous attempts to build predictive models often have low predictive power, with concordance indexes (c-index) less than 0.70.

METHODS

Using the National Cancer Database (2010-2014), we identified patients with synchronous metastatic rectal cancer. The data was split into a training dataset (diagnosis years 2010-2012), which was used to build the machine learning model, and a testing dataset (diagnosis years 2013-2014), which was used to externally validate the model. A nomogram predicting 3-year OS was created using Cox proportional hazard regression with lasso penalization. Predictors were selected based on clinical significance and availability in NCDB. Performance of the machine learning model was assessed by c-index.

RESULTS

A total of 4098 and 3107 patients were used to construct and validate the nomogram, respectively. Internally validated c-indexes at 1, 2, and 3 years were 0.816 (95% CI 0.813-0.818), 0.789 (95% CI 0.786-0.790), and 0.778 (95% CI 0.775-0.780), respectively. External validated c-indexes at 1, 2, and 3 years were 0.811, 0.779, and 0.778, respectively.

CONCLUSIONS

There is wide variability in the OS for patients with metastatic rectal cancer, making accurate predictions difficult. However, using machine learning techniques, more accurate models can be built. This will aid patients and clinicians in setting expectations and making clinical decisions in this group of challenging patients.

Circulating Tumor Cells and Circulating Tumor DNA Detection in Potentially Resectable Metastatic Colorectal Cancer: A Prospective Ancillary Study to the Unicancer Prodige-14 Trial

The management of patients with colorectal cancer (CRC) and potentially resectable liver metastases (LM) requires quick assessment of mutational status and of response to pre-operative systemic therapy. In a prospective phase II trial (NCT01442935), we investigated the clinical validity of circulating tumor cell (CTC) and circulating tumor DNA (ctDNA) detection. CRC patients with potentially resectable LM were treated with first-line triplet or doublet chemotherapy combined with targeted therapy. CTC (Cellsearch^®) and Kirsten RAt Sarcoma (KRAS) ctDNA (droplet digital polymerase chain reaction (PCR)) levels were assessed at inclusion, after 4 weeks of therapy and before LM surgery. 153 patients were enrolled. The proportion of patients with high CTC counts (≥3 CTC/7.5mL) decreased during therapy: 19% (25/132) at baseline, 3% (3/108) at week 4 and 0/57 before surgery. ctDNA detection sensitivity at baseline was 91% (N=42/46) and also decreased during treatment. Interestingly, persistently detectable KRAS ctDNA (p=0.01) at 4 weeks was associated with a lower R0/R1 LM resection rate. Among patients who had a R0/R1 LM resection, those with detectable ctDNA levels before liver surgery had a shorter overall survival (p<0.001). In CRC patients with limited metastatic spread, ctDNA could be used as liquid biopsy tool. Therefore, ctDNA detection could help to select patients eligible for LM resection.

Pancreatic, periampullary and biliary cancer with liver metastases: Should we consider resection in selected cases?

AIM

To analyse the safety and efficacy of curative intent surgery in biliary and pancreatic cancer.

METHODS

An extensive literature review was performed using MEDLINE, Google Scholar and EMBASE to identify articles regarding hepato-pancreatoduodenectomy or resection of liver metastasis in patients with pancreatic, biliary tract, periampullary and gallbladder cancers.

RESULTS

A total of 19 studies were identified and reviewed. Major hepatectomy was undertaken in 391 patients. The median overall survival for pancreatic cancer ranged from 5-36 mo and for biliary tract/gallbladder cancer, it was 8-38 mo. The 30 d mortality rate was only 1%-9%. Overall Survival was significantly better for patients, who had good response to neoadjuvant chemotherapy, underwent metachronous liver resection and who had intestinal type tumours.

CONCLUSION

Resection of liver metastases in pancreatic and biliary cancers may provide survival benefit without compromising safety and quality of life in a very select group of patients. These data may be utilised to formulate selection criteria that may allow future investigation of resection in the era of more effective systemic therapy.

Neoadjuvant Oxaliplatin-based Chemotherapy for Liver Metastases from Colorectal Cancer. An Italian Survey

Background

Only 10% to 25% of patients with liver metastases from colorectal cancer are suitable for resection. Methods for increasing the resectability of liver metastases are based on specific surgical techniques and neoadjuvant chemotherapy.

Methods

We collected retrospective data on patients from various Italian hospitals from 1996 to 2002. Data from colorectal cancer patients with liver metastases treated with oxaliplatin-based neoadjuvant chemotherapy were considered. Analysis focused on patients and treatment description and on long-term survival. We considered 107 patients from 36 Italian hospitals.

Results

Of the 105 patients assessable for response, 8.4% achieved a complete response, 70.1% a partial response and 19.6% stable disease. Ninety-nine patients were treated with surgery for liver metastases. A radical resection was achieved in 79% of patients. Median survival time was 42 months. Thirteen patients experienced grade 3-4 hematologic toxicity, and 10 patients had grade 3-4 nonhematologic toxicity. Neurologic toxicity of grade >1 was observed in 21% of patients.

Conclusions

Neoadjuvant chemotherapy can be useful to increase the number of liver resections for metastatic colorectal cancer patients. Nevertheless, randomized trials are necessary to confirm this retrospective survey as well as the few single-institution experiences reported so far in the medical literature.

18FDG-PET Evaluation Correlates Better than CT with Pathological Response in a Metastatic Colon Cancer Patient Treated with Bevacizumab-Based Therapy

Around 20–30% of patients with hepatic metastasis from colorectal cancer can undergo liver resection, but the increased response rate obtained with the addition of monoclonal antibodies to chemotherapy regimens could result in a higher rate of liver surgery. In this report we describe the case of a patient who underwent a liver resection after neoadjuvant treatment with capecitabine, oxaliplatin and bevacizumab and who achieved a complete pathological response of the liver metastasis. A preoperative CT scan demonstrated a partial response to the treatment while 18FDG-PET scan correctly evaluated the complete pathological response in the liver and detected an active interaortocaval lymph node metastasis. New specific studies are required to evaluate the imaging response in metastatic colorectal cancer patients especially after treatment with new, targeted agents.

Prospective phase II trial of combination hepatic artery infusion and systemic chemotherapy for unresectable colorectal liver metastases: Long term results and curative potential

BACKGROUND/OBJECTIVES

Combination hepatic artery infusion (HAI) and systemic (SYS) chemotherapy for unresectable CRLM results in high tumor-response rates. This study represents an update of long-term survival and conversion to resectability in patients with unresectable CRLM treated with HAI and SYS chemotherapy in a phase II study.

METHOD

The primary endpoint was complete resection. Multivariate and landmark analysis assessed the effect of complete resection on progression-free (PFS) and overall survival (OS).

RESULTS

From 2007 to 2012, 64 patients with median of 13 tumors were enrolled; 67% had prior chemotherapy. 33 patients (52%) were converted to resection. Median follow-up among survivors was 81 months. Median PFS and OS were 13 and 38 months, respectively, with 5-year-OS of 36%. Chemotherapy-naïve patients had 5-year-OS of 51%. Conversion to resection was the only independent factor prognostic of improved PFS and OS. Nine of 64 patients (14%) are NED (five since initial resection, three after resection of recurrent disease, one from chemotherapy alone) at median follow-up of 86 months from treatment initiation, and 72 months from last operative intervention.

CONCLUSION

Combination HAI and SYS is an effective therapy for high-volume unresectable CRLM, resulting in a high rate of resection, long-term survival, and the potential for cure.

Resection of Colorectal Liver Metastases: Current Perspectives

BACKGROUND

Metastases to the liver is the leading cause of death in patients with colorectal cancer.

METHODS

The authors review the data on diagnosis and management of this clinical problem, and they discuss management options that can be considered.

RESULTS

Complete surgical resection of metastases from colorectal cancer that are localized to the liver results in 5-year survival rates ranging from 26% to 40%.

CONCLUSIONS

By adding modalities such as targeted systemic therapy and other "local" treatments for liver metastases, further gains in survival are anticipated.

Liver-directed therapy in metastatic colorectal cancer

INTRODUCTION

Colorectal cancer is a significant global health issue with over 1 million cases diagnosed annually throughout the world. 15% of patients diagnosed with colorectal cancer will have liver metastases and 60% will develop liver metastases if they have metastatic disease. Oligometastatic colorectal cancer confined to the liver represents an intermediate state in the evolution of metastatic capacity that opens the opportunity for local interventions. Areas covered: The literature supports long-term survival if patients undergo liver resection of colorectal metastases. This article reviews the liver-directed therapeutic strategies available for the management of metastatic liver disease including hepatic arterial infusion therapy, radiofrequency ablation, radiation therapy and transarterial chemoembolization. Expert commentary: Great advances have been made with the use of liver directed therapies. In the USA using hepatic arterial infusions with FUDR and Decadron along with systemic therapy, 5 year survivals after liver resection have improved. In Europe with the use of HAI of Oxaliplatin, more patients have been able to get to resection and have obtained higher survival rates, even in second line therapy. New advances in ablative therapy have improved results to get all disease treated at resection for the treatment of reccurrence.

Effect of adjuvant chemotherapy after pulmonary metastasectomy on the prognosis of colorectal cancer

Background

Adjuvant chemotherapy after resection of colorectal cancer (CRC) lung metastases may reduce recurrences and improve survival. We investigated the effects of adjuvant chemotherapy after curative resection of lung CRC metastases on prognosis.

Methods

We retrospectively reviewed records of our patients undergoing pulmonary metastasectomy from CRC between January 2000–March 2014. Data were analyzed with Kaplan-Meier survival analysis and Cox proportional hazards models.

Results

One-hundred (56 men; median age, 66 years) of 128 consecutive patients who underwent complete resection for first lung colorectal metastases were analyzed. Postoperative 5-year rates of overall survival (OS) and relapse-free survival (RFS) were 76% and 41%, respectively. Adjuvant chemotherapy strongly affected RFS and OS by multivariable analysis compared to surgery alone (RFS: HR, 0.49; 95% CI, 0.27–0.88; P = 0.016 and OS: HR, 0.35; 95% CI, 0.14–0.81; P = 0.014). Similar effects of adjuvant chemotherapy occurred in subgroups respectively classified according to number of lung metastases and preoperative serum carcinoembryonic antigen (CEA) level.

Conclusions

Adjuvant chemotherapy after curative resection of lung metastases might strongly affect the prognosis of metastatic CRC patients. Even patients with single metastatic lesions and normal preoperative CEA level appeared to receive benefits from such chemotherapy. Narrowing of suitable candidates by predicting the effects of systemic chemotherapy and prospective randomized studies are needed.

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Adjuvant chemotherapy after pulmonary metastasectomy might strongly affect prognosis of metastatic CRC patients.

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Even patients with single metastatic lesions and normal preoperative CEA level appeared to receive benefits from such chemotherapy.

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Narrowing of suitable candidates by predicting the effects of systemic chemotherapy and prospective randomized studies are needed.

Chemotherapy Plus Cetuximab versus Chemotherapy Alone for Patients with KRAS Wild Type Unresectable Liver-Confined Metastases Colorectal Cancer: An Updated Meta-Analysis of RCTs

Purpose. Our study analyses clinical trials and evaluates the efficacy of adding cetuximab in systematic chemotherapy for unresectable colorectal cancer liver-confined metastases patients. Materials and Methods. Search EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials for RCTs comparing chemotherapy plus cetuximab with chemotherapy alone for KRAS wild type patients with colorectal cancer liver metastases (CRLMs). We calculated the relative risks (RRs) with 95% confidence interval and performed meta-analysis of hazard ratios (HRs) for the R0 resection rate, the overall response rate (ORR), the progression-free survival (PFS) and overall survival (OS). Results. 1173 articles were retrieved and 4 RCTs were available for our study. The four studies involved 504 KRAS wild type patients with CRLMs. The addition of cetuximab significantly improved all the 4 outcomes: the R0 resection rate (RR 2.03, p = 0.004), the ORR (RR 1.76, p < 0.00001), PFS (HR 0.63, p < 0.0001), and also OS (HR 0.74, p = 0.04); the last outcome is quite different from the conclusion published before. Conclusions. Although the number of patients analysed was limited, we found that the addition of cetuximab significantly improves the outcomes in KRAS wild type patients with unresectable colorectal cancer liver-confined metastases. Cetuximab combined with systematic chemotherapy perhaps suggests a promising choice for KRAS wild type patients with unresectable liver metastases.

Selective internal radiation therapy for liver metastases from colorectal cancer

Liver metastases are often the dominant site of metastatic disease in colorectal cancer. Selective internal radiation therapy (SIRT) involves embolising radiolabeled spheres (SIR-Spheres) into the arterial supply of the liver. This review assesses the effectiveness and toxicity of SIRT in the treatment of metastatic colorectal cancer liver metastasis when given alone or with systemic or regional hepatic artery chemotherapy. We reviewed only randomised controlled trials comparing SIRT and chemotherapy (systemic and/or regional) with chemotherapy alone, or comparing SIRT alone with best supportive care. Only four randomized trials were identified. Due to heterogeneity of the patients and treatments received it was not possible to perform a formal meta-analysis, therefore this is a descriptive analysis only. All studies included patients with either liver only or liver dominant metastatic colorectal cancer. Two trials compared SIRT alone and SIRT with chemotherapy first line. The first with only 21 patients revealed a significant improvement in PFS and median survival with SIRT. The larger second study SIRFLOX of 530 patients comparing SIRT and current standard first line FOLFOX chemotherapy (+/- bevacizumab) with standard FOLFOX+/-bevacizumab alone. There was no improvement in overall PFS with addition of SIRT. In chemotherapy refractory patients SIRT and systemic chemotherapy (fluorouracil) improved progression free survival but not overall survival. A final study (63 patients) compared SIRT and regional chemotherapy (floxuridine) with regional chemotherapy alone in first line showed no significant difference in progression free survival and median survival. There remains a lack of evidence that SIRT improves survival or quality of life in patients with metastatic colorectal cancer. The overall survival results from SIRFLOX combined with FOXFIRE and FOXFIRE Global are awaited.

Prospective evaluation of 18F-fluorodeoxyglucose positron emission tomography in patients receiving hepatic arterial and systemic chemotherapy for unresectable colorectal liver metastases

BACKGROUND

The prognostic and predictive abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) coupled with conventional computed tomography (CT) have not been studied in patients with unresectable colorectal liver metastases (uCRLM) treated with combined hepatic arterial infusion (HAI) and systemic chemotherapy.

OBJECTIVES

The ability of PET-CT metabolic response parameters to predict conversion to resectability and oncologic outcome in this setting was evaluated.

METHODS

Thirty-eight patients undergoing serial PET-CT as part of a Phase II trial of HAI and systemic chemotherapy for uCRLM were included. Metabolic response was determined as the percentage change in standard uptake value (SUV) and total lesion glycolysis (TLG). Conversion to resection, overall survival (OS), progression-free survival (PFS) and recurrence-free survival were evaluated using standard statistics.

RESULTS

Volumetric response sufficient to facilitate resection was seen in 53% of patients after a median of 5 months of therapy. Median follow-up was 38 months (range: 32-52 months). Median OS was not reached [95% confidence interval (CI) 32 months-unknown] and 3-year OS was 54% (range: 33-71%). Median PFS was 13 months (95% CI 6-21 months) and 3 year PFS was 10% (range: 3-20%). Neither baseline values nor the percentage change in any of the metabolic parameters evaluated correlated with conversion to resection, survival variables or hepatic recurrence on Cox regression analysis.

CONCLUSIONS

Pre- and post-treatment PET-related metabolic parameters do not predict conversion to resection or oncologic outcome in patients with uCRLM treated with HAI and systemic chemotherapy. Metabolic parameters should not be used to monitor response or to determine prognosis in these patients.

Proposal for novel histological findings of colorectal liver metastases with preoperative chemotherapy

This study aimed to clarify the histological characteristics related to preoperative chemotherapy for colorectal liver metastases (CRLM). Sixty-three patients with CRLM were divided into two groups: CRLM with chemotherapy (41 cases, group A) and CRLM without chemotherapy (22 cases; surgical treatment alone, group S) to identify the histological differences associated with chemotherapy. In addition, we investigated the effects of combination chemotherapy on the histology of metastatic lesions. Infarct-like necrosis (ILN), three-zonal changes, and cholesterol clefts were more frequent in group A than in group S (P < 0.05). ILN and three-zonal changes were more common in the 5-FU with leucovorin and oxaliplatin (FOLFOX), or 5-FU with leucovorin and irinotecan (FOLFIRI) with or without additional bevacizumab groups than in group S (P < 0.05). Cholesterol clefts in the FOLFOX or FOLFIRI with bevacizumab group and foamy macrophages in the FOLFOX or FOLFIRI group were more common than in group S (P < 0.05). Cases with more than three of the four histological findings--i.e. ILN, three-zonal changes, cholesterol clefts, and foamy macrophages--were more frequent in the FOLFOX or FOLFIRI with or without additional bevacizumab groups than in group S (P < 0.05). We showed histological findings for every representative chemotherapy regimen for CRLM to clarify the effects of preoperative chemotherapy.

Phase II trial of hepatic artery infusional and systemic chemotherapy for patients with unresectable hepatic metastases from colorectal cancer: conversion to resection and long-term outcomes

PURPOSE

Evaluate conversion rate of patients with unresectable colorectal-liver metastasis to complete resection with hepatic-arterial infusion plus systemic chemotherapy including bevacizumab (Bev).

PATIENTS AND METHODS

Forty-nine patients with unresectable colorectal liver metastases (CRLM) were included in a single-institution phase II trial. Conversion to resection was the primary outcome. Secondary outcomes included overall survival (OS), progression-free survival, and response rates. Multivariate and landmark analyses were performed to evaluate survival differences between resected and nonresected patients.

RESULTS

Median number of tumors was 14 and 65% were previously treated patients. A high biliary toxicity rate was found in the first 24 patients whose treatment included Bev. The remaining 25 patients were treated without Bev. Overall response rates were 76% (4 complete responses). Twenty-three patients (47%) achieved conversion to resection at a median of 6 months from treatment initiation. Median OS and progression-free survival for all patients were 38 (95% confidence interval: 28 to not reached) and 13 months (95% confidence interval: 7-16). Bev administration did not impact outcome. Conversion was the only factor associated with prolonged OS and progression-free survival in multivariate analysis. On landmark analysis, patients who had undergone resection had longer OS than those who did not undergo resection (3-year OS: 80% vs 26%). Currently, 10 of 49 (20%) patients have no evidence of disease (NED) at a median follow-up of 39 months (32-65 months).

CONCLUSIONS

In patients with extensive unresectable CRLM, the majority of whom were previously treated, 47% were able to undergo complete resection after combined HAI and systemic therapy. Conversion to resection is associated with prolonged survival.

Colorectal cancer with liver metastases: Neoadjuvant chemotherapy, surgical resection first or palliation alone?

Colorectal cancer (CRC) is one of the commonest cancers with 1.2 million new cases diagnosed each year in the world. It remains the fourth most common cause of cancer-related mortality in the world and accounts for > 600000 cancer-related deaths each year. There have been significant advances in treatment of metastatic CRC in last decade or so, due to availability of new active targeted agents and more aggressive approach towards the management of CRC, particularly with liver-only-metastases; however, these drugs work best when combined with conventional chemotherapy agents. Despite these advances, there is a lack of biomarkers to inform us about the accurate management of the patients with metastatic CRC. It is therefore imperative to carefully select the patients with comprehensive multi-disciplinary team input in order to optimise the management of these patients. In this review we will discuss various treatment options available in management of colorectal liver metastases with potential guidance on how and when to choose these options along with consideration on future directions in management of this disease.

Disparities in survival improvement for metastatic colorectal cancer by race/ethnicity and age in the United States

PURPOSE

Previous studies documented significant increase in overall survival for metastatic colorectal cancer (CRC) since the late 1990s coinciding with the introduction and dissemination of new treatments. We examined whether this survival increase differed across major racial/ethnic populations and age groups.

METHODS

We identified patients diagnosed with primary metastatic colorectal cancer during 1992-2009 from 13 population-based cancer registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results Program, which cover about 14 % of the US population. The 5-year cause-specific survival rates were calculated using SEER*Stat software.

RESULTS

From 1992-1997 to 2004-2009, 5-year cause-specific survival rates increased significantly from 9.8 % (95 % CI 9.2-10.4) to 15.7 % (95 % CI 14.7-16.6) in non-Hispanic whites and from 11.4 % (95 % CI 9.4-13.6) to 17.7 % (95 % CI 15.1-20.5) in non-Hispanic Asians, but not in non-Hispanic blacks [from 8.6 % (95 % CI 7.2-10.1) to 9.8 % (95 % CI 8.1-11.8)] or Hispanics [from 14.0 % (95 % CI 11.8-16.3) to 16.4 % (95 % CI 14.0-19.0)]. By age group, survival rates increased significantly for the 20-64-year age group and 65 years or older age group in non-Hispanic whites, although the improvement in the older non-Hispanic whites was substantially smaller. Rates also increased in non-Hispanic Asians for the 20-64-year age group although marginally nonsignificant. In contrast, survival rates did not show significant increases in both younger and older age groups in non-Hispanic blacks and Hispanics.

CONCLUSION

Non-Hispanic blacks, Hispanics, and older patients diagnosed with metastatic CRC have not equally benefitted from the introduction and dissemination of new treatments.

Factors influencing choice of chemotherapy in metastatic colorectal cancer (mCRC)

Management of metastatic colorectal cancer requires a multimodal approach and must be performed by an experienced, multidisciplinary expert team. The optimal choice of the individual treatment modality, according to disease localization and extent, tumor biology, and patient clinical characteristics, will be one that can maintain quality of life and long-term survival, and even cure selected patients. This review is an overview of the different therapeutic approaches available in metastatic colorectal cancer, for the purpose of defining personalized therapeutic algorithms according to tumor biology and patient clinical features.

A phase II clinical study of mFOLFOX6 plus bevacizumab as first-line therapy for Japanese advanced/recurrent colorectal cancer patients

Objective

In Japan, there had been no prospective clinical studies conducted in terms of modified FOLFOX6 + bevacizumab therapy. We performed a post-marketing Phase II multicenter clinical study to examine the efficacy and safety of this regimen as first-line therapy for Japanese patients with advanced/recurrent colorectal cancer.

Methods

Bevacizumab (5 mg/kg) was administered intravenously, and then oxaliplatin (85 mg/m²) and levofolinate calcium (200 mg/m²) were infused intravenously over 2 h. Subsequently, a bolus dose of 5-fluorouracil (400 mg/m²) was injected, followed by infusion of 5-fluorouracil (2400 mg/m²) for 46 h. This regimen was repeated every 2 weeks until 24 cycles unless there was disease progression, unacceptable toxicity or patient refusal. The primary end point was the response rate.

Results

Among the 70 patients enrolled, two patients withdrew the study before treatment, and 68 patients were eligible for analysis of efficacy and safety. The response rate was 51.5% (95% confidence interval: 39.0–63.8%). The median progression-free survival and median overall survival time were 12.6 months (95% confidence interval: 10.4–14.5 months) and 28.5 months [95% confidence interval: 23.1 months–(not applicable)], respectively. There were no treatment-related deaths observed. The most common Grade 3 and 4 adverse events included neutropenia in 35.3% of the patients, peripheral neuropathy in 16.2% and hypertension in 16.2%. All adverse events were manageable and tolerable. The exploratory analysis of polymorphisms of three genes, ERCC1, XPD and GSTP1, did not show any trends in terms of correlation with the efficacy or safety of modified FOLFOX6 + bevacizumab therapy.

Conclusions

Modified FOLFOX6 + bevacizumab therapy was manageable and tolerable in Japanese patients, achieving a high response rate.

What is the optimal neo-adjuvant treatment for liver metastasis?

Colorectal cancer is the third most common cancer in the Western population and has a 5-year overall survival of 5-10% when metastatic. Approximately 30% of the patients with metastatic colorectal cancer have limited disease apparently isolated to the liver and, if this can be resected, the 5-year overall survival is improved to 30-60%. Therefore, it is important to identify patients who have both resectable disease and those with initially unresectable tumors who can potentially be downsized with chemotherapy to allow resection. First-line doublet chemotherapy regimens lead to response rates of 50-60%, triplet chemotherapy regimens may result in a response rate of up to 70%, and biological agents may add to responses or induce morphologic changes that facilitate disease resection. Surgical advances in recent years have also increased resectability rates and have challenged prior rules of resectability. Local therapies including ablation and radiation, often performed in conjunction with resection, may further aid in control of disease. The aim of this article is to focus on the role of neoadjuvant therapy in the treatment of colorectal liver metastases.

Randomized controlled trial of cetuximab plus chemotherapy for patients with KRAS wild-type unresectable colorectal liver-limited metastases

PURPOSE

To assess the effects of cetuximab plus chemotherapy as first-line treatment for unresectable colorectal liver metastases (CLMs).

PATIENTS AND METHODS

After resection of their primary tumors, patients with KRAS wild-type synchronous nonresectable liver-limited metastases from colorectal cancer were randomly assigned to receive chemotherapy (FOLFIRI [fluorouracil, leucovorin, and irinotecan] or mFOLFOX6 [modified fluorouracil, leucovorin, and oxaliplatin]) plus cetuximab (arm A) or chemotherapy alone (arm B). The primary end point was the rate of patients converted to resection for liver metastases. Secondary end points included tumor response and survival.

RESULTS

The intent-to-treat population comprised 138 patients; 70 patients were randomly assigned to arm A and 68 to arm B. After a median of 25.0 months of follow-up, the 3-year overall survival (OS) rate and median survival time (MST) for all patients were 30% and 24.4 months, respectively. The R0 resection rates for liver metastases were 25.7% (18 of 70 patients) in arm A and 7.4% (five of 68 patients) in arm B, which were significantly different (P < .01). Patients in arm A had improved objective response rates (57.1% v 29.4%; P < .01), increased 3-year OS rate (41% v 18%; P = .013) and prolonged MST (30.9 v 21.0 months; P = .013) compared with those in arm B. In addition, in arm A, patients who had resection of liver metastases had a significantly improved MST (46.4 v 25.7 months; P < .01) compared with those who did not undergo surgery.

CONCLUSION

For patients with initially unresectable KRAS wild-type CLMs, cetuximab combined with chemotherapy improved the resectability of liver metastases and improved response rates and survival compared with chemotherapy alone.

Predictors for early recurrence after hepatectomy for initially unresectable colorectal liver metastasis

BACKGROUND

Early recurrence correlates with poor survival following various cancer surgeries and puts considerable stress on patients both physically and mentally. This retrospective study investigated the predictive factors for early recurrence after surgical resection for initially unresectable colorectal liver metastasis to elucidate indications for conversion strategies.

METHODS

We retrospectively studied 46 patients who underwent hepatectomy after chemotherapy for initially unresectable colorectal liver metastasis from 1997 to 2010.

RESULTS

Recurrences occurred within 6 months after hepatectomy in 13 patients (37 %). The median survival time of 21.2 months and the 5-year survival rate of 0 % after hepatectomy in patients with recurrence within 6 months were significantly worse than those in patients with recurrence more than 6 months after hepatectomy. Recurrence in less than 6 months was significantly correlated with impossibility of anticancer therapy for recurrence after hepatectomy (p = 0.01). Eight or more hepatic tumors after chemotherapy were the only predictor of recurrence within 6 months (p = 0.01; odds ratio 9.6; 95 % confidence interval 1.5-60.6).

CONCLUSION

Recurrence within 6 months was significantly correlated with a poorer outcome following surgery for initially unresectable colorectal liver metastasis. Surgical indication for initially unresectable colorectal liver metastasis with eight or more hepatic tumors after chemotherapy should be considered carefully in the light of mental and physical status, co-morbidity, and alternative treatment plans.

Tumour-microenvironment interactions: role of tumour stroma and proteins produced by cancer-associated fibroblasts in chemotherapy response

BACKGROUND

Cytotoxic chemotherapy improves survival for some, but not all, cancer patients. Non-responders may experience unnecessary toxicity and cancer progression, thus creating an urgent need for biomarkers that can predict the response to chemotherapy. So far, the search for such biomarkers has primarily been focused on the cancer cells and less on their surrounding stroma. This stroma is known to act as a key regulator of tumour progression and, in addition, has been associated with drug delivery and drug efficacy. Fibroblasts represent the major cell type in cancer-associated stroma and they secrete extracellular matrix proteins as well as growth factors. This Medline-based literature review summarises the results from studies on epithelial cancers and aimed at investigating relationships between the quantity and quality of the intra-tumoral stroma, the cancer-associated fibroblasts, the proteins they produce and the concomitant response to chemotherapy. Biomarkers were selected for review that are known to affect cancer-related characteristics and patient prognosis.

RESULTS

The current literature supports the hypothesis that biomarkers derived from the tumour stroma may be useful to predict response to chemotherapy. This notion appears to be related to the overall quantity and cellularity of the intra-tumoural stroma and the predominant constituents of the extracellular matrix.

CONCLUSION

Increasing evidence is emerging showing that tumour-stroma interactions may not only affect tumour progression and patient prognosis, but also the response to chemotherapy. The tumour stroma-derived biomarkers that appear to be most appropriate to determine the patient's response to chemotherapy vary by tumour origin and the availability of pre-treatment tissue. For patients scheduled for adjuvant chemotherapy, the most promising biomarker appears to be the PLAU: SERPINE complex, whereas for patients scheduled for neo-adjuvant chemotherapy the tumour stroma quantity appears to be most relevant.

Defining resectability of colorectal liver metastases: how and why?

SUMMARY Treatment outcome in metastatic colorectal carcinoma has improved because of advancements in medical therapy and increased use of liver resections. In primary nonresectable disease, prognosis improves when a secondary resection is performed after successful downsizing by neoadjuvant systemic therapy. Which patient groups may profit from a secondary liver resection and which neoadjuvant systemic therapy has the optimal chance of conversion to resectability has not been defined because various patient groups were selected in different studies and there is a lack of consensus on resectability. This invalidates cross-study comparisons of resection rates and survival rates. Prospective trials in which secondary resection rate is a predefined end point are needed and will allow more insight into this topic.

Phase II trial of upfront bevacizumab and temozolomide for unresectable or multifocal glioblastoma

Patients with unresectable glioblastomas have a poor prognosis, with median survival of 6–10 months. We conducted a phase II trial of upfront 5-day temozolomide (TMZ) and bevacizumab (BV) in patients with newly diagnosed unresectable or multifocal glioblastoma. Patients received up to four cycles of TMZ at 200 mg/m² on days 1–5, and BV at 10 mg/kg on days 1 and 15 of a 28-day cycle. Brain magnetic resonance imaging (MRI) was performed monthly. Therapy was continued as long as there was no tumor progression, grade 4 nonhematologic toxicity, or recurrent grade 4 hematologic toxicity after dose reduction. The primary end point was best tumor response as measured on MRI. Forty-one patients were accrued over 12 months; 39 had a full set of MRI scans available for evaluation. Assessment for best radiographic responses was as follows: partial responses in 24.4%, stable disease in 68.3%, and progressive disease in 2.4%. Treatment-related toxicities included seven grade 4 toxicities and one grade 5 toxicity (myocardial infarction). From this study, it was concluded that an upfront regimen of TMZ and BV for unresectable glioblastoma was well tolerated and provided a significant level of disease stabilization. Therapeutic toxicities were consistent with those seen in the adjuvant setting using these agents. The upfront approach to treatment of glioblastoma in the unresectable population warrants further investigation in randomized controlled phase III trials.

Phase II trial of first-line chemoradiotherapy with intensity-modulated radiation therapy followed by chemotherapy for synchronous unresectable distant metastases rectal adenocarcinoma

Aims

Based on the hypothesis that first-line chemoradiation followed by chemotherapy was superior for primary tumor and non-inferior for distant lesions compared to chemotherapy alone in synchronous unresectable distant metastases rectal adenocarcinoma, this study was designed to assess the efficacy and safety of this strategy.

Materials and methods

Thirty two eligible patients received intensity modulated radiation therapy (45 Gy to the pelvis and a concomitant 10 Gy boost to the gross tumor), along with concurrent weekly capecitabine and oxaliplatin. Patients underwent radical surgery if all lesions were visually evaluated as resectable and received chemotherapy for a total of 6 months, whether pre- or post-operatively (definitive therapy group). The remaining patients received 6 months of consolidation chemotherapy followed by maintenance chemotherapy (non-definitive therapy group).

Results

The toxicities were acceptable, with radiation-induced dermatitis around the anal verge being the most common (18.8%). Fourteen patients underwent surgical resection of the rectal tumor, with 5 (35.7%) experiencing a pathological complete response. Nine out of 14 received definitive treatment, defined as R0 resections of all visible tumors. At a median follow-up of 12 months (range, 4–23 months), 2 cases were evaluated as local failure, and the median overall survival (OS) and progression free survival (PFS) for all 32 patients were 17.5 and 12 months, respectively. OS differed significantly in the definitive and non-definitive therapy groups (p=0.045), and PFS tended to differ (p=0.274).

Conclusion

It was demonstrated that the strategy of first-line chemoradiation followed by chemotherapy was effective and tolerable, especially for local control. OS and PFS were superior in patients who did than did not undergo curative therapy.

Surgical options for initially unresectable colorectal liver metastases

Although the frontiers of liver resection for colorectal liver metastases have broadened in recent decades, approximately 75% of these patients present with unresectable metastases at the time of their diagnosis. In the past, these patients underwent only palliative treatment, without the chance of a cure. In the previous two decades, several therapeutic strategies have been developed that render resectable those metastases that were initially unresectable, thus offering the chance of long-term survival and even a cure to these patients. The oncosurgical modalities that are available include liver resection following portal vein ligation/embolization, “two-stage” liver resection, one-stage ultrasonically guided liver resection, hepatectomy following conversion chemotherapy, and liver resection combined with thermal ablation. Moreover, in recent years, certain authors have recommended the revisiting of the concept of liver transplantation in highly selected patients with unresectable colorectal liver metastases and favorable prognostic factors. By employing such therapies, the number of patients with colorectal liver metastases who undergo a potentially curative treatment could increase to 40%. The safety profile of these approaches is acceptable (morbidity rates as high as 45%, mortality rates of less than 5%). Furthermore, the 5-year survival rates (approximately 30%) are significantly increased over those that were achieved with palliative treatment.

Impact of hepatic lymph node metastasis on survival of patients with synchronous resectable or unresectable liver metastases of colorectal cancer

BACKGROUND

The goals of this retrospective study were to comprehensively evaluate the impact of hepatic lymph node (HLN) involvement on survival in patients with synchronous resectable or unresectable liver metastases from colorectal cancer and to highlight how to deal with such cases in the light of recent advances in chemotherapy.

METHODS

The impact of HLN involvement on survival, along with various clinical, pathological, and therapeutic factors, was retrospectively evaluated in 61 patients with synchronous liver metastases from colorectal cancer (resectable, 26; unresectable, 35), undergoing resection of the primary tumor and histopathological evaluation between July 2000 and April 2008.

RESULTS

The proportion with HLN metastasis was 11.5 % in resectable cases and 28.6 % in unresectable cases. On multivariate analysis using the Cox proportional hazards model, HLN metastasis (P < 0.001), along with non-resection of hepatic lesions (P < 0.001), larger metastatic tumor volume (P < 0.001), non-use of oxaliplatin-based chemotherapy (P < 0.001), involvement of 4 or more regional lymph nodes (P < 0.001), and excessive lymphatic invasion (P = 0.02), was identified as an independent risk factor for shorter survival.

CONCLUSIONS

To establish a new therapeutic strategy for synchronous liver metastasis of colorectal cancer, the HLNs should be examined histologically in patients undergoing resection of their primary colon and rectal cancer.

Evaluating agreement regarding the resectability of colorectal liver metastases: a national case-based survey of hepatic surgeons

BACKGROUND

The resectability of colorectal liver metastases is in part largely based on the surgeon's assessment of cross-sectional imaging. This process, while guided by principles, is subjective. The objective of the present study was to assess agreement between hepatic surgeons regarding the resectability of colorectal liver metastases.

METHODS

Forty-six hepatic surgeons across Canada were invited. A patient with biologically favourable disease was presented after having received neoadjuvant chemotherapy. The scenario was matched with 10 different scrollable abdominal CT scans representing a maximum response after six cycles of chemotherapy. Surgeons were asked to offer an opinion on resectability of liver metastases, and whether they would use adjunct modalities to hepatic resection.

RESULTS

Twenty-six surgeons participated. Twenty responses were complete. The median number of scenarios deemed resectable was 6/10 (range 3-8). Two control scenarios demonstrated perfect agreement. Agreement on resectability was poor for 4/8 test scenarios, of which one scenario demonstrated complete disagreement. Among resectable cases, the pattern of use of adjunct modalities was variable. A median ratio of 0.87 adjunct modality per resectable scenario per surgeon was used (range 0.25-1.75).

CONCLUSION

A significant lack of agreement was identified among surgeons on the resectability and use of adjunct modalities in the treatment of colorectal liver metastases.

Preoperative imaging of colorectal liver metastases after neoadjuvant chemotherapy: a meta-analysis

Background

Chemotherapy treatment induces parenchymal changes that potentially affect imaging of CRLM. The purpose of this meta-analysis was to provide values of diagnostic performance of magnetic resonance imaging (MRI), computed tomography (CT), fluorodeoxyglucose positron emission tomography (FDG-PET), and FDG-PET/CT for preoperative detection of colorectal liver metastases (CRLM) in patients treated with neoadjuvant chemotherapy.

Methods

A comprehensive search was performed for original articles published from inception to 2011 assessing diagnostic performance of MRI, CT, FDG-PET, or FDG-PET/CT for preoperative evaluation of CRLM following chemotherapy. Intraoperative findings and/or histology were used as reference standard. For each imaging modality we calculated pooled sensitivities for patients who received neoadjuvant chemotherapy as well as for chemonaive patients, defined as number of malignant lesions detected divided by number of malignant lesions as confirmed by the reference standard.

Results

A total of 11 papers, comprising 223 patients with 906 lesions, were included. Substantial variation in study design, patient characteristics, imaging features, and reference tests was observed. Pooled sensitivity estimates of MRI, CT, FDG-PET, and FDG-PET/CT were 85.7% (69.7–94.0%), 69.9% (65.6–73.9%), 54.5% (46.7–62.1%), and 51.7% (37.8–65.4%), respectively. In chemonaive patients, sensitivity rates were 80.5% (67.0–89.4%) for CT, 81.3% (64.1–91.4%) for FDG-PET, and 71.0% (64.3–76.9%) for FDG-PET/CT. Specificity could not be calculated because of non-reporting of “true negative lesions.”

Conclusion

In the neoadjuvant setting, MRI appears to be the most appropriate imaging modality for preoperative assessment of patients with CRLM. CT is the second-best diagnostic modality and should be used in the absence of MRI. Diagnostic accuracy of FDG-PET and PET-CT is strongly affected by chemotherapy.