Advances in understanding of colorectal liver metastasis and implications for the clinic

Probiotics formulation and cancer nanovaccines show synergistic effect in immunotherapy and prevention of colon cancer

Probiotics play essential roles in immune modulation. Combining probiotics with cancer vaccines potentially can achieve a synergistic effect. To maximize the efficacy of probiotics, proper probiotics formulation is necessary. Herein, Lactobacillus rhamnosus and Bifidobacterium longum are coated with lipid membrane to achieve the goal of losing less activity and bettering colonization in colon. In the subcutaneous transplanted colon cancer mouse model, probiotics formulation showed potent preventive and therapeutic efficacy, and the efficacy could be further improved by combining with cancer nanovaccines. Probiotics formulation can perform as immune adjuvants to enhance the innate immune response or as in-situ cancer vaccines. In the study of preventing chemical-induced orthotopic colon cancer model, probiotics formulation alone efficiently reduced tumor number in colon and the efficacy is improved by combining with cancer nanovaccines. All in all, the studies demonstrated that probiotics formulation can assist to maximize the efficacy of cancer nanovaccines.

A Review of Herbal Resources Inducing Anti-Liver Metastasis Effects in Gastrointestinal Tumors via Modulation of Tumor Microenvironments in Animal Models

Liver metastases remain a major obstacle for the management of all types of tumors arising from digestive organs, and the tumor microenvironment has been regarded as an important factor in metastasis. To discover herbal candidates inhibiting the liver metastasis of tumors originating from the digestive system via the modulation of the tumor microenvironment and liver environment, we searched three representative public databases and conducted a systematic review. A total of 21 studies that employed experimental models for pancreatic (9), colon (8), and stomach cancers (4) were selected. The herbal agents included single-herb extracts (5), single compounds (12), and multiherbal decoctions (4). Curcuma longa Linn was most frequently studied for its anti-colon-liver metastatic effects, and its possible mechanisms involved the modulation of tumor microenvironment components such as vascular endothelial cells and immunity in both tumor tissues and circulating cells. The list of herbal agents and their mechanisms produced in this study is helpful for the development of anti-liver metastasis drugs in the future.

A PRRX1 Signature Identifies TIM-3 and VISTA as Potential Immune Checkpoint Targets in a Subgroup of Microsatellite Stable Colorectal Cancer Liver Metastases

Disease recurrence and drug resistance are major challenges in the clinical management of patients with colorectal cancer liver metastases (CLM), and because tumors are generally microsatellite stable (MSS), responses to immune therapies are poor. The mesenchymal phenotype is overrepresented in treatment-resistant cancers and is associated with an immunosuppressed microenvironment. The aim of this work was to molecularly identify and characterize a mesenchymal subgroup of MSS CLM to identify novel therapeutic approaches. We here generated a mesenchymal gene expression signature by analysis of resection specimens from 38 patients with CLM using ranked expression level of the epithelial-to-mesenchymal transition-related transcription factor PRRX1. Downstream pathway analysis based on the resulting gene signature was performed and independent, publicly available datasets were used to validate the findings. A subgroup comprising 16% of the analyzed CLM samples were classified as mesenchymal, or belonging to the PRRX1 high group. Analysis of the PRRX1 signature genes revealed a distinct immunosuppressive phenotype with high expression of immune checkpoints HAVCR2/TIM-3 and VISTA, in addition to the M2 macrophage marker CD163. The findings were convincingly validated in datasets from three external CLM cohorts. Upregulation of immune checkpoints HAVCR2/TIM-3 and VISTA in the PRRX1 high subgroup is a novel finding, and suggests immune evasion beyond the PD-1/PD-L1 axis, which may contribute to poor response to PD-1/PD-L1-directed immune therapy in MSS colorectal cancer. Importantly, these checkpoints represent potential novel opportunities for immune-based therapy approaches in a subset of MSS CLM.

Significance

CLM is an important cause of colorectal cancer mortality where the majority of patients have yet to benefit from immunotherapies. In this study of gene expression profiling analyses, we uncovered novel immune checkpoint targets in a subgroup of patients with MSS CLMs harboring a mesenchymal phenotype.

Effect of tumour size ratio on liver recurrence-free survival of patients undergoing hepatic resection for colorectal liver metastases

Background

The study aimed to assess the impact of size differences of multiple liver metastases on liver recurrence-free survival (RFS) in patients undergoing hepatic resection for colorectal liver metastases (CRLMs).

Methods

Overall, 147 patients with CRLMs who underwent hepatic resection between January 2010 and December 2016 were retrospectively analysed. Tumour size ratio (TSR) was defined as the maximum diameter of the largest liver lesion over the maximum diameter of the smallest liver lesion. The univariate and multivariate analyses were performed to determine independent prognostic risk factors. The prognostic value of the TSR was further explored in each Tumour Burden Score (TBS) zone. Log-rank survival analyses were used to compare liver RFS in the new clinical score and the Fong clinical score.

Results

Based on the TSR, patients were classified into three groups: TSR < 2, 2 ≤ TSR < 4, and TSR ≥ 4. According to the multivariate analysis, TSR of 2–4 (hazard ratio [HR], 2.580; 95% confidence interval [CI] 1.543–4.312; P < 0.001) and TSR < 2 (HR, 4.435; 95% CI 2.499–7.872; P < 0.001) were associated with worse liver RFS. As TSR decreased, liver RFS worsened. TSR could further stratify patients in zones 1 and 2 into different risk groups according to the TBS criteria (zone 1: median liver RFS, 3.2 and 8.9 months for groups 1 and 2, respectively, P = 0.003; zone 2: median liver RFS, 3.5, 5.0, and 10.9 months for groups 1, 2, and 3, respectively, P < 0.05). The predictive ability of the new clinical score, which includes TSR, was superior to that of the Fong clinical score.

Conclusions

TSR, as a prognostic tool, could accurately assess the effect of size differences across multiple liver metastases on liver RFS in patients undergoing hepatectomy for CRLMs.

Trial registration

Retrospectively registered

Advances in liver transplantation for unresectable colon cancer liver metastasis

It is estimated that 50% of patients with colorectal cancer will develop liver metastasis. Surgical resection significantly improves survival and provides a chance of cure for patients with colorectal cancer liver metastasis (CRLM). Increasing the resectability of primary unresectable liver metastasis provides more survival benefit for those patients. Considerable surgical innovations have been made to increase the resection rate and decrease the potential risk of hepatic failure postoperation. Liver transplantation (LT) has been explored as a potential curative treatment for unresectable CRLM. However, candidate selection criteria, chemotherapy strategies, refined immunity regimens and resolution for the shortage of grafts are lacking. This manuscript discusses views on surgical indication, peritransplantation anti-tumor and anti-immunity therapy and updated advances in LT for unresectable CRLM. A literature review of published articles and registered clinical trials in PubMed, Google Scholar, and Clinicaltrials.gov was performed to identify studies related to LT for CRLM. Some research topics were identified, including indications for LT for CRLM, oncological risk, antitumor regimens, graft loss, administration of anti-immunity drugs and solutions for graft deficiency. The main candidate selection criteria are good patient performance, good tumor biological behavior and chemosensitivity. Chemotherapy should be administered before transplantation but is not commonly administered posttransplantation for preventive purposes. Mammalian target of rapamycin regimens are recommended for their potential oncological benefit, although there are limited cases. In addition to extended criterion grafts, living donor grafts and small grafts combined with two-stage hepatectomy are efficient means to resolve organ deficiency. LT has been proven to be an effective treatment for selected patients with liver-only CRLM. Due to limited donor grafts, high cost and poorly clarified oncological risks, LT for unresectable CRLM should be strictly performed under a well-organized study plan in selected patients. Some vital factors, like LT indication and anti-tumor and anti-immune treatment, remain to be confirmed. Ongoing clinical trials are expected to delineate these topics.

Role of liver transplantation in the management of colorectal liver metastases: Challenges and opportunities

The liver is the most common site of colorectal cancer metastasis. Complete resection of the metastatic tumor is currently the only treatment modality available with a potential for cure. However, only 20% of colorectal liver metastases (CRLM) are considered resectable at the time of presentation. Liver transplantation (LT) has been proposed as an alternative oncologic treatment for patients with unresectable CRLM. This review summarizes the published experiences of LT in the setting of unresectable CRLM from the previous decades and discusses the challenges and future horizons in the field. Contemporary experiences that come mostly from countries with broader access to liver grafts are also explored and their promising findings in terms of overall survival (OS) and disease-free survival (DFS) are outlined along with their study design and methods. The rationale of establishing specific patient selection criteria and the dilemmas around immunosuppressive regimens in patients undergoing LT for CRLM are also highlighted. Additionally, this review describes the findings of studies comparing LT vs chemotherapy alone and LT vs portal vein embolization plus resection for CRLM in terms of OS and DFS. Last but not least, we present current perspectives and ongoing prospective trials that try to elucidate the role of LT for CRLM.

Missing colorectal liver metastases: the surgical challenge

BACKGROUND

New chemotherapy schemes have allowed for a better radiological response of unresectable colorectal liver metastases, leading to an interesting scenario known as a complete radiological response. The aim of this study was to review the current management of missing liver metastases (MLM) from the liver surgeon's point of view.

METHODS

A systematic search was conducted on all publications of PubMed and Embase between 2003 and 2018. Meta-analysis was performed on MLM resected/unresected. Residual tumor or regrowth and relapse-free survival were used as evaluation indices.

RESULTS

After literature search, 18 original articles were included for analysis. The predictive factors for MLM are type and duration of chemotherapy and size and number of lesions. Magnetic resonance is the most sensitive preoperative technique. Regarding clinical management, liver surgery is deemed the fundamental pillar in the therapeutic strategy of these patients. Meta-analysis due to data heterogeneity was inconclusive.

CONCLUSIONS

Depending on the clinical context, MLM monitoring appears to be a valid therapeutic alternative. Nevertheless, prospective randomized clinical studies are needed.

Prognostic impact of additive chemotherapy after curative resection of metachronous colorectal liver metastasis: a single-centre retrospective study

Background

A prognostic benefit of additive chemotherapy in patients following resection of metachronous colorectal liver metastases (CRLM) remains controversial. Therefore, the goal of this retrospective study was to investigate the impact of perioperative chemotherapy on disease-free survival (DFS) and overall survival (OS) of patients after curative resection of metachronous CRLM.

Methods

In a retrospective single-centre study, patients after curative resection of metachronous CRLM were included and analysed for DFS and OS with regard to the administration of additive chemotherapy. The Kaplan-Meier method was applied to compare DFS and OS while Cox regression models were used to identify independent prognostic variables.

Results

Thirty-four of 75 patients were treated with additive 5-FU based chemotherapy. OS was significantly prolonged in this patient subgroup (62 vs 57 months; p = 0.032). Additive chemotherapy significantly improved 10-year survival rates (42% vs 0%, p = 0.023), but not 5-year survival (58% vs 42%, p = 0.24). Multivariate analysis identified additive chemotherapy (p = 0.016, HR 0.44, 95% CI 0.23–0.86), more than five CRLM (p = 0.026, HR 2.46, 95% CI 1.16–10.32) and disease recurrence (0.009, HR 2.70, 95% CI 1.29–5.65) as independent risk factors for OS.

Conclusion

Additive chemotherapy significantly prolonged OS and 10-year survival in patients after curative resection of metachronous CRLM. Randomized clinical trials are needed in the future to identify optimal chemotherapy regimens for those patients.

Expanding Indications for Liver Transplant: Tumor and Patient Factors

During the past few decades, liver transplant has developed from a high-mortality procedure to an almost routine procedure with good survival outcomes. The development of living donor liver transplant has increased the availability of liver grafts, and the scope of indications for liver transplant has been expanding ever since. The aim of this review is to provide an overview of such an expansion of scope. Various criteria have been proposed to expand the eligibility of patients with hepatocellular carcinoma exceeding the Milan criteria for liver transplant. Furthermore, liver transplant is increasingly performed as a treatment modality for cholangiocarcinoma, neuroendocrine liver metastasis and colorectal liver metastasis. The number of elderly patients receiving liver transplant is on the rise. Combined organ transplantation has also been adopted to treat patients with multiple organ failure. Going forward, further development of preoperative noninvasive predictors in tumor, patient and even donor factors is needed to identify patients at risk of poor outcomes and hence optimize patient management.

Response to preoperative chemotherapy: impact of change in total burden score and mutational tumor status on prognosis of patients undergoing resection for colorectal liver metastases

BACKGROUND

Progression of colorectal liver metastasis (CRLM) on preoperative chemotherapy has been associated with a worse prognosis compared with patients who have responsive disease. Defining response can be challenging as traditional criteria largely assess only tumor size.

METHODS

Patients who underwent hepatectomy between 2010 and 2017 were identified using a multi-centric database. This study aimed to define the impact of preoperative chemotherapy response relative to initial tumor burden score (TBS) and determine impact of clinico-pathological variables on overall survival (OS).

RESULTS

Among 784 patients who received preoperative chemotherapy, the regimen was oxaliplatin- (66%) or irinotecan-based (34%). Among patients with a TBS<6 at diagnosis, genetic status was the most important prognostic variable. Patients with a TBS<6, 5-year OS was 55%, 35%, and 0% for patients with KRAS/NRAS/BRAF wild-type, KRAS/NRAS, and BRAF mutations, respectively. Among patients who presented with CRLM with a TBS≥6, only Δ-TBS was prognostically important and patients with a Δ-TBS ≥ -10% had a 5-year OS of 27% compared with 49% for patients with a Δ-TBS < -10%.

CONCLUSIONS

Prognostic stratification of patients with CRLM receiving preoperative chemotherapy should be multi-faceted and include consideration of initial tumor burden, change in tumor burden due to chemotherapy, and tumor genetic status.

Radioembolization treatment for liver metastases

The liver is an organ that, due to vascularisation and functions, is prone to metastases. Most liver metastases are observed in cases of gastrointestinal cancers in: stomach, colon, gallbladder, and bile ducts. Metastatic lesions are also observed in lung, breast, thyroid, kidney, and pancreatic cancer. One of the best known and most effective ways of liver lesion treatment is Metastasectomy. Unfortunately, lesions are frequently inoperable. Apart from chemotherapy, it is possible to apply local treatment such as TACE (trans-arterial chemoembolisation), RFA (Radio Frequency Ablation), and SBRT (Stereotactic Body Radiation Therapy). One of the newest methods of inoperable lesion treatment is radioembolisation (SIRT). Intravascular administration of microspheres containing radioisotope 90Y allows delivery of a higher dose of radiation directly to the tumour than traditional radiation with an external beam, while maintaining a small dose to healthy liver methods. Conducted clinical studies confirm the efficacy and safety of SIRT. It is an interesting alternative to other ways of treatment.

The Potential Role of Liver Transplantation as a Treatment Option in Colorectal Liver Metastases

Liver resection is the only potentially curative treatment option in patients with liver metastases from colorectal cancer, but only about 20% of the patients are resectable. Liver transplantation of patients with unresectable liver metastases was attempted in the early era but it was abandoned due to poor survival. During the last decade, several case reports, a controlled pilot study, and a retrospective cohort study indicated that prolonged disease-free survival and overall survival can be obtained in a proportion of these patients. Strict selection criteria have not yet been well defined, but tumor load, response to chemotherapy, pretransplant carcinoembryonic antigen level, and time interval from resection of the primary tumor to transplant are all factors related to outcome. Carefully selected patients may obtain 5-year overall survival that approaches conventional indications for liver transplant. The scarcity of liver grafts is a significant problem, but this can possibly to some extent be addressed by use of extended criteria grafts and novel surgical techniques. There is an increasing interest in liver transplantation in these patients in the transplant community, and currently 4 clinical trials are active and are recruiting.

Molecular signatures reflecting microenvironmental metabolism and chemotherapy-induced immunogenic cell death in colorectal liver metastases

Background

Metastatic colorectal cancer (CRC) is associated with highly variable clinical outcome and response to therapy. The recently identified consensus molecular subtypes (CMS1-4) have prognostic and therapeutic implications in primary CRC, but whether these subtypes are valid for metastatic disease is unclear. We performed multi-level analyses of resectable CRC liver metastases (CLM) to identify molecular characteristics of metastatic disease and evaluate the clinical relevance.

Methods

In this ancillary study to the Oslo-CoMet trial, CLM and tumor-adjacent liver tissue from 46 patients were analyzed by profiling mutations (targeted sequencing), genome-wide copy number alteration (CNAs), and gene expression.

Results

Somatic mutations and CNAs detected in CLM were similar to reported primary CRC profiles, while CNA profiles of eight metastatic pairs suggested intra-patient divergence. A CMS classifier tool applied to gene expression data, revealed the cohort to be highly enriched for CMS2. Hierarchical clustering of genes with highly variable expression identified two subgroups separated by high or low expression of 55 genes with immune-related and metabolic functions. Importantly, induction of genes and pathways associated with immunogenic cell death (ICD) was identified in metastases exposed to neoadjuvant chemotherapy (NACT).

Conclusions

The uniform classification of CLM by CMS subtyping may indicate that novel class discovery approaches need to be explored to uncover clinically useful stratification of CLM. Detected gene expression signatures support the role of metabolism and chemotherapy in shaping the immune microenvironment of CLM. Furthermore, the results point to rational exploration of immune modulating strategies in CLM, particularly by exploiting NACT-induced ICD.

Liver transplantation for unresectable colorectal liver metastases: A systematic review

The use of liver transplantation (LT) for liver metastases attempted in the early 1990's was associated with poor perioperative outcomes and unacceptably low overall survival. Recently, there has been renewed interest in LT as a treatment option for colorectal liver metastases (CLM) in countries where organ supply is high. To date, no meticulous analysis about the efficacy, safety and outcomes of LT in CLM patients has been published. We present the first systematic review on the subject.

Identification of liver metastases with probe-based confocal laser endomicroscopy at two excitation wavelengths

BACKGROUND

Metastasis of colorectal cancer to the liver is the most common indication for hepatic resection in a western population. Incomplete excision of malignancy due to residual microscopic disease normally results in worse patient outcome. Therefore, a method aiding in the real time discrimination of normal and malignant tissue on a microscopic level would be of benefit.

MATERIAL AND METHODS

The ability of fluorescent probe-based confocal laser endomicroscopy (pCLE) to identify normal and malignant liver tissue was evaluated in an orthotopic murine model of colorectal cancer liver metastasis (CRLM). To maximise information yield, two clinical fluorophores, fluorescein and indocyanine green (ICG) were injected and imaged in a dual wavelength approach (488 and 660 nm, respectively). Visual tissue characteristics on pCLE examination were compared with histological features. Fluorescence intensity in both tissues was statistically analysed to elucidate if this can be used to differentiate between normal and malignant tissue.

RESULTS

Fluorescein (488 nm) enabled good visualisation of normal and CRLM tissue, whereas ICG (660 nm) visualisation was limited to normal liver tissue only. Fluorescence intensity in areas of CRLM was typically 53-100% lower than normal hepatic parenchyma. Using general linear mixed modelling and receiver operating characteristic analysis, high fluorescence intensity was found to be statistically more likely in normal hepatic tissue.

CONCLUSION

Real time discrimination between normal liver parenchyma and metastatic tissue with pCLE examination of fluorescein and ICG is feasible. Employing two (rather than a single) fluorophores allows a combination of qualitative and quantitative characteristics to be used to distinguish between hepatic parenchyma and CRLM. Lasers Surg. Med. 49:280-292, 2017. © 2016 Wiley Periodicals, Inc.

No Differences in Symptom Burden Between Colorectal Cancer Patients Receiving Curative Versus Palliative Chemotherapy

CONTEXT

Colorectal cancer (CRC) is one of the most common cancers worldwide. Patients with CRC may have multiple cooccurring symptoms as a result of their disease or its treatment. Little is known about potential differences in symptom burden in CRC patients scheduled to receive curative versus palliative chemotherapy (CTX).

OBJECTIVES

The purposes of this study were to investigate the overall symptom burden of patients with CRC before their first CTX treatment or before the initiation of a new CTX regimen and to evaluate for differences in symptom occurrence, severity, and distress between patients with CRC who were scheduled to receive curative versus palliative CTX.

METHODS

Consecutive patients with CRC were recruited (n = 120), and symptoms were assessed using the Memorial Symptom Assessment Scale before the initiation of the CTX. The most common symptoms that occurred in ≥30% of the patients were evaluated. Differences in occurrence rates and severity and distress scores between the curative (n = 68) and palliative (n = 52) patient groups were evaluated using binary logistic regression and ordinal logistic regression analyses, respectively.

RESULTS

In both groups, patients reported an average of 10 cooccurring symptoms. Worrying (65%), lack of energy (59%), feeling drowsy (54%), feeling bloated (53%), pain (51%), and difficulty sleeping (50%) were the most prevalent symptoms. Problems with sexual interest had the highest severity and distress scores in both groups. For the 13 most common symptoms, no significant differences were found between the two patient groups on any of the Memorial Symptom Assessment Scale dimensions (i.e., occurrence, severity, distress).

CONCLUSION

Regardless of the reason for CTX, CRC patients experience a large number of cooccurring symptoms.

An overview of imaging techniques for liver metastases management

Evaluation of liver metastases is one of the most common indications for liver imaging. Imaging plays a key role in the of assessment liver metastases. A variety of imaging techniques, including ultrasonography, computed tomography, MRI and PET combined with CT scan are available for diagnosis, planning treatment, and follow-up treatment response. In this paper, the authors present the role of imaging for the assessment of liver metastases and the contribution of each of the different imaging techniques for their evaluation and management. Following recent developments in the field of oncology, the authors also present the importance of imaging for the assessment of liver metastases response to therapy. Finally, future perspectives on imaging of liver metastases are presented.

Considerations, challenges and future of anti-TNF therapy in treating inflammatory bowel disease

INTRODUCTION

Crohn's disease (CD) and ulcerative colitis (UC) are chronic disabling conditions. Monoclonal antibody therapy directed against tumor necrosis factor-alpha (anti-TNF) has revolutionized the care of patients with inflammatory bowel disease (IBD).

AREAS COVERED

Considerations before starting anti-TNF therapy are highlighted: the best time to start with anti-TNF therapy, either alone or in combination with an immunomodulator, the choice of an anti-TNF agent and the contra-indications to anti-TNF therapy. Primary nonresponse and secondary loss of response are discussed. De-escalating therapy, the role of therapeutic drug monitoring and the use of biosimilars, are handled. Finally, the future directions of anti-TNF therapy are emphasized.

EXPERT OPINION

Anti-TNF therapy remains the cornerstone in the treatment of IBD. When initiating long-term therapy, safety and cost issues are of great importance. The therapeutic armamentarium in the treatment of IBD is rapidly growing. Therefore, the challenge is to optimize the use and refine the exact position of anti-TNF therapy in the near future, with personalized medicine as the ultimate goal.

β-catenin-independent WNT signaling and Ki67 in contrast to the estrogen receptor status are prognostic and associated with poor prognosis in breast cancer liver metastases

Liver metastasis development in breast cancer patients is common and confers a poor prognosis. So far, the prognostic significance of surgical resection and clinical relevance of biomarker analysis in metastatic tissue have barely been investigated. We previously demonstrated an impact of WNT signaling in breast cancer brain metastasis. This study aimed to investigate the value of established prognostic markers and WNT signaling components in liver metastases. Overall N = 34 breast cancer liver metastases (with matched primaries in 19/34 cases) were included in this retrospective study. Primaries and metastatic samples were analyzed for their expression of the estrogen (ER) and progesterone receptor, HER-2, Ki67, and various WNT signaling-components by immunohistochemistry. Furthermore, β-catenin-dependent and -independent WNT scores were generated and analyzed for their prognostic value. Additionally, the influence of the alternative WNT receptor ROR on signaling and invasiveness was analyzed in vitro. ER positivity (HR 0.09, 95 % CI 0.01–0.56) and high Ki67 (HR 3.68, 95 % CI 1.12–12.06) in the primaries had prognostic impact. However, only Ki67 remained prognostic in the metastatic tissue (HR 2.46, 95 % CI 1.11–5.44). Additionally, the β-catenin-independent WNT score correlated with reduced overall survival only in the metastasized situation (HR 2.19, 95 % CI 1.02–4.69, p = 0.0391). This is in line with the in vitro results of the alternative WNT receptors ROR1 and ROR2, which foster invasion. In breast cancer, the value of prognostic markers established in primary tumors cannot directly be translated to metastases. Our results revealed β-catenin-independent WNT signaling to be associated with poor prognosis in patients with breast cancer liver metastasis.