Fatty change of the liver microenvironment influences the metastatic potential of colorectal cancer

Biomarkers of systemic treatment response: MR images of intratumoral fat deposition in colorectal liver metastases (CRLM) after chemotherapy

PURPOSE

Colorectal cancer cells containing mobile lipids are said to be an early indicator of chemotherapy effects. The objective of the study was to examine the frequency and clinical relevance of intratumoral fat deposition in colorectal liver metastases (CRLM) post-chemotherapy using dual-echo chemical shift gradient-echo magnetic resonance imaging (MRI).

METHODS

A retrospective analysis of 98 patients with CRLM diagnosed between 2017 and 2022 (69 M, mean age 62.87 ± 10.73 years old) who had an MRI after chemotherapy was performed. On dual-echo chemical shift gradient-echo MRI, intratumoral fat deposition of CRLM was evaluated. A signal intensity drop of ≥ 12% in opposed-phase images vs. in-phase images indicated intratumoral fat. After chemotherapy, the presence of fat deposition was correlated with patients' overall survival.

RESULTS

Before and after chemotherapy, 0 (0%) and 29 (29.59%) patients exhibited intratumoral fat. The number of CRLM ranged from 1 to 25 with a median of 3 and a mean size of 32.58 ± 22.95 mm. The groups had statistically different survival times. Overall survival was shorter for patients with intratumoral fat deposition in CRLM (32 months (24-60, 95% CI)) than for patients without fat deposition in CRLM (48 months (36-NA, 95% CI)).

CONCLUSION

In our group, nearly 30% of CRLM patients exhibited intratumoral fat after chemotherapy. Patients with intratumoral fat deposition in CRLM have a shorter overall survival time. The presence of fat in CRLM correlates with a poor long-term prognosis.

The Prognostic Impact of Adipophilin Expression on Long-Term Survival Following Liver Resection in Patients with Colorectal Liver Metastases

Background/Objectives: Adipophilin (ADP) is a protein associated with lipid droplets, and its expression is related to poor prognosis in certain cancers. However, its impact on the survival of patients with colorectal liver metastases (CRLMs) remains unclear. This study investigated the impact of ADP expression on long-term survival following hepatectomy in patients with CRLM. Methods: We retrospectively analyzed 102 consecutive patients who underwent hepatectomy between 2006 and 2022. ADP expression was examined in resected specimens through immunohistochemical staining using tissue microarrays. Long-term outcomes for ADP-positive (n = 51) and ADP-negative (n = 51) groups were compared with Kaplan-Meier survival analysis. Results: We found significantly decreased 5-year recurrence-free survival (RFS) and overall survival (OS) rates for ADP-positive patients relative to ADP-negative patients (29.4% versus 52.1%, respectively; p = 0.001 and 43.7% versus 72.2%, respectively; p = 0.003). Moreover, multivariate Cox hazards analysis demonstrated that patients with ADP-positive CRLM had a worse prognosis after hepatectomy than those with ADP-negative CRLM, as reflected by both RFS (HR 2.46, 95% CI 1.39-4.36, p = 0.002) and OS (HR: 2.89, 95% CI 1.43-5.85, p = 0.003). Conclusions: ADP expression had a significant prognostic impact on the survival of patients with CRLM following liver resection and may aid in optimal treatment planning.

Hepatic steatosis predicts metachronous liver metastasis in colorectal cancer patients: a nested case-control study and systematic review

Nearly twenty-five percent of colorectal cancer (CRC) patients develop metachronous colorectal liver metastasis (CRLM) after curative surgery. Hepatosteatosis is the most prevalent liver condition worldwide, but its impact on the incidence of metachronous CRLM is understudied. In the present study, we aimed to investigate the predictive value of hepatic steatosis on the development of metachronous CRLM. First, a nested case-control study was conducted, enrolling stage I to III CRC patients in the National Colorectal Cancer Cohort (NCRCC) database. Metachronous CRLM patients and recurrence-free patients were matched via propensity-score matching. Fatty liver was identified based on treatment-naïve CT scans and the degree of hepatic fibrosis was scored. Multivariable analysis was conducted to investigate the association between fatty liver and metachronous CRLM. In our database, a total of 414 patients were included. Metachronous CRLM patients had considerably higher rates of hepatic steatosis (30.9% versus 15.9%, P<0.001) and highly fibrotic liver (11.6% versus 2.9%, P=0.001) compared to recurrence-free patients. Multivariable analysis showed that fatty liver (odds ratios [OR]=1.99, 95% confidence interval [CI] 1.19-3.30, P=0.008) and fibrotic liver (OR=4.27, 95% CI 1.54-11.81, P=0.005) were associated with high risk of metachronous CRLM. Further, a systematic literature review was performed to assess available evidence on the association between hepatosteatosis and development of metachronous CRLM. In the systematic review, 1815 patients were pooled from eligible studies, and hepatic steatosis remained a significant risk factor for metachronous CRLM (OR=1.90, 95% CI 1.35-2.66, P<0.001, I2=25.3%). In conclusion, our data suggest that patients with a steatotic liver and a high fibrosis score at CRC diagnosis have elevated risk of developing metachronous CRLM.

Cells in the liver microenvironment regulate the process of liver metastasis

The research of liver metastasis is a developing field. The ability of tumor cells to invade the liver depends on the complicated interactions between metastatic cells and local subpopulations in the liver (including Kupffer cells, hepatic stellate cells, liver sinusoidal endothelial cells, and immune-related cells). These interactions are mainly mediated by intercellular adhesion and the release of cytokines. Cell populations in the liver microenvironment can play a dual role in the progression of liver metastasis through different mechanisms. At the same time, we can see the participation of liver parenchymal cells and nonparenchymal cells in the process of liver metastasis of different tumors. Therefore, the purpose of this article is to summarize the relationship between cellular components of liver microenvironment and metastasis and emphasize the importance of different cells in the occurrence or potential regression of liver metastasis.

Altered lipid metabolism as a predisposing factor for liver metastasis in MASLD

Recently, the incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing due to the high prevalence of metabolic conditions, such as obesity and type 2 diabetes mellitus. Steatotic liver is a hotspot for cancer metastasis in MASLD. Altered lipid metabolism, a hallmark of MASLD, remodels the tissue microenvironment, making it conducive to the growth of metastatic liver cancer. Tumors exacerbate the dysregulation of hepatic metabolism by releasing extracellular vesicles and particles into the liver. Altered lipid metabolism influences the proliferation, differentiation, and functions of immune cells, contributing to the formation of an immunosuppressive and metastasis-prone liver microenvironment in MASLD. This review discusses the mechanisms by which the steatotic liver promotes liver metastasis progression, focusing on its role in fostering an immunosuppressive microenvironment in MASLD. Furthermore, this review highlights lipid metabolism manipulation strategies for the therapeutic management of metastatic liver cancer.

Inhibitory effect of non-alcoholic steatohepatitis on colon cancer liver metastasis

BACKGROUND

The incidence of non-alcoholic steatohepatitis (NASH) is dramatically increasing, but the effect of NASH on colon cancer liver metastasis (CLM) is controversial. The aim of this study was to investigate the impact and mechanism of action of NASH on CLM using a western diet (WD)-fed mouse model.

METHODS

Six-week-old male C57BL/6 J mice were used. They were divided into the WD group and control group with normal diet. MC38 colon cancer cells were injected into the spleen at 2, 6, 8 and 16 weeks, and mice were killed at 2 weeks after injection to evaluate hepatic steatosis, fibrosis, metastasis and mRNA/protein expression in the liver.

RESULTS

Only mice fed a WD for 16 weeks showed hepatic fibrosis. These mice showed significantly higher alanine aminotransferase and total cholesterol levels compared with the control group (p < 0.05). The WD group showed significantly lower tumor number and smaller tumor diameter (p < 0.05). In the WD group, expression of SAA1, IL6, STAT3 and MMP9 mRNA in the liver was significantly lower than in the control group (p < 0.05). Serum amyloid A1 protein expression was also lower in the WD group.

CONCLUSIONS

The WD-fed NASH mouse model showed an inhibitory effect on CLM. Suppressed interleukin-6/signal transducer and activator of transcription 3 signaling and serum amyloid A/matrix metalloproteinase 9 expression may affect this phenomenon.

Clearing Steatosis Prior to Liver Surgery for Colorectal Metastasis: A Narrative Review and Case Illustration

Over recent years, non-alcoholic fatty liver disease (NAFLD) has become the most common liver disorder in the developed world, accounting for 20% to 46% of liver abnormalities. Steatosis is the hallmark of NAFLD and is recognized as an important risk factor for complication and death after general surgery, even more so after liver resection. Similarly, liver steatosis also impacts the safety of live liver donation and transplantation. We aim to review surgical outcomes after liver resection for colorectal metastases in patients with steatosis and discuss the most common pre-operative strategies to reduce steatosis. Finally, as illustration, we report the favorable effect of a low-caloric, hyper-protein diet during a two-stage liver resection for colorectal metastases in a patient with severe steatosis.

Histopathological growth patterns of liver metastasis: updated consensus guidelines for pattern scoring, perspectives and recent mechanistic insights

The first consensus guidelines for scoring the histopathological growth patterns (HGPs) of liver metastases were established in 2017. Since then, numerous studies have applied these guidelines, have further substantiated the potential clinical value of the HGPs in patients with liver metastases from various tumour types and are starting to shed light on the biology of the distinct HGPs. In the present guidelines, we give an overview of these studies, discuss novel strategies for predicting the HGPs of liver metastases, such as deep-learning algorithms for whole-slide histopathology images and medical imaging, and highlight liver metastasis animal models that exhibit features of the different HGPs. Based on a pooled analysis of large cohorts of patients with liver-metastatic colorectal cancer, we propose a new cut-off to categorise patients according to the HGPs. An up-to-date standard method for HGP assessment within liver metastases is also presented with the aim of incorporating HGPs into the decision-making processes surrounding the treatment of patients with liver-metastatic cancer. Finally, we propose hypotheses on the cellular and molecular mechanisms that drive the biology of the different HGPs, opening some exciting preclinical and clinical research perspectives.

Whole-liver enhanced CT radiomics analysis to predict metachronous liver metastases after rectal cancer surgery

Background

To develop a radiomics model based on pretreatment whole-liver portal venous phase (PVP) contrast-enhanced CT (CE-CT) images for predicting metachronous liver metastases (MLM) within 24 months after rectal cancer (RC) surgery.

Methods

This study retrospectively analyzed 112 RC patients without preoperative liver metastases who underwent rectal surgery between January 2015 and December 2017 at our institution. Volume of interest (VOI) segmentation of the whole-liver was performed on the PVP CE-CT images. All 1316 radiomics features were extracted automatically. The maximum-relevance and minimum-redundancy and least absolute shrinkage and selection operator methods were used for features selection and radiomics signature constructing. Three models based on radiomics features (radiomics model), clinical features (clinical model), and radiomics combined with clinical features (combined model) were built by multivariable logistic regression analysis. Receiver operating characteristic (ROC) curves were used to assess the diagnostic performance of models, and calibration curve and the decision curve analysis were performed to evaluate the clinical application value.

Results

In total, 52 patients in the MLM group and 60 patients in the non-MLM group were enrolled in this study. The radscore was built using 16 selected features and the corresponding coefficients. Both the radiomics model and the combined model showed higher diagnostic performance than clinical model (AUCs of training set: radiomics model 0.84 (95% CI, 0.76–0.93), clinical model 0.65 (95% CI, 0.55–0.75), combined model 0.85 (95% CI, 0.77–0.94); AUCs of validation set: radiomics model 0.84 (95% CI, 0.70–0.98), clinical model 0.58 (95% CI, 0.40–0.76), combined model 0.85 (95% CI, 0.71–0.99)). The calibration curves showed great consistency between the predicted value and actual event probability. The DCA showed that both the radiomics and combined models could add a net benefit on a large scale.

Conclusions

The radiomics model based on preoperative whole-liver PVP CE-CT could predict MLM within 24 months after RC surgery. Clinical features could not significantly improve the prediction efficiency of the radiomics model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-022-00485-z.

Fat signal fraction assessed with MRI predicts hepatic recurrence following hepatic resection for colorectal liver metastases

PURPOSE

The effect of hepatic steatosis on the development of colorectal liver metastases (CRLM) remains unknown. This study evaluated the usefulness of fat signal fraction assessed with magnetic resonance imaging (MRI) and the effect of hepatic steatosis on hepatic recurrences following initial hepatectomy for CRLM.

METHODS

Between January 2013 and December 2019, 64 patients underwent initial hepatectomy for CRLM. The medical records of these patients were reviewed to evaluate the recurrence and survival outcomes.

RESULTS

The fat signal fraction was positively correlated with the nonalcoholic fatty liver disease activity score and liver-spleen ratio. Recurrence following the initial hepatectomy was observed in 48/64 patients, and hepatic recurrence was observed in 30/64 patients. The fat signal fraction was significantly higher in patients with hepatic recurrence after initial hepatectomy. The hepatic recurrence rate was 69.2% in patients with fat signal fraction ≥ 0.0258, which was significantly higher than that in patients with fat signal fraction < 0.0258. Hepatic recurrence-free survival rate was significantly higher in patients with fat signal fraction < 0.0258 than in those with fat signal fraction ≥ 0.0258. Multivariate analyses revealed that fat signal fraction ≥ 0.0258 was an independent risk factor for hepatic recurrence.

CONCLUSION

The fat signal fraction assessed with MRI was significantly associated with hepatic recurrence following initial hepatectomy for CRLM.

The Effect of Diffuse Liver Diseases on the Occurrence of Liver Metastases in Cancer Patients: A Systematic Review and Meta-Analysis

This systematic review with meta-analysis aimed to assess the effect of diffuse liver diseases (DLD) on the risk of synchronous (S-) or metachronous (M-) liver metastases (LMs) in patients with solid neoplasms. Relevant databases were searched for systematic reviews and cross-sectional or cohort studies published since 1990 comparing the risk of LMs in patients with and without DLD (steatosis, viral hepatitis, cirrhosis, fibrosis) in non-liver solid cancer patients. Outcomes were prevalence of S-LMs, cumulative risk of M-LMs and LM-free survival. Risk of bias (ROB) was assessed using the Newcastle-Ottawa Scale. We report the pooled relative risks (RR) for S-LMs and hazard ratios (HR) for M-LMs. Subgroup analyses included DLD, primary site and continent. Nineteen studies were included (n = 37,591 patients), the majority on colorectal cancer. ROB appraisal results were mixed. Patients with DLD had a lower risk of S-LMs (RR 0.50, 95% CI 0.34-0.76), with a higher effect for cirrhosis and a slightly higher risk of M-LMs (HR 1.11 95% CI, 1.03-1.19), despite a lower risk of M-LMs in patients with vs without viral hepatitis (HR 0.57, 95% CI 0.40-0.82). There may have been a publication bias in favor of studies reporting a lower risk for patients with DLD. DLD are protective against S-LMs and slightly protective against M-LMs for viral hepatitis only.

Lipid metabolism in cancer: New perspectives and emerging mechanisms

Tumors undergo metabolic transformations to sustain uncontrolled proliferation, avoid cell death, and seed in secondary organs. An increased focus on cancer lipid metabolism has unveiled a number of mechanisms that promote tumor growth and survival, many of which are independent of classical cellular bioenergetics. These mechanisms include modulation of ferroptotic-mediated cell death, support during tumor metastasis, and interactions with the cells of the tumor microenvironment. As such, targeting lipid metabolism for anti-cancer therapies is attractive, with recent work on small-molecule inhibitors identifying compounds to target lipid metabolism. Here, we discuss these topics and identify open questions.

Fatty change of the liver microenvironment influences the metastatic potential of colorectal cancer

Fatty liver is the most common cause of liver disease, and its prevalence has been increasing globally. Colorectal cancer (CRC) accounts for approximately 10% of all cancers and metastasizes most commonly to the liver. Paget's ‘Seed and Soil’ theory of metastasis proposed that the secondary growth of cancer cells is dependent on the distal organ microenvironment. This implies that the risk of metastasis may change due to changes in the microenvironment of target organs. However, the association between steatosis, fatty change in the liver microenvironment, and liver metastasis has not been clarified. Here, we induced fatty liver conditions in BALB/c mice using a choline‐deficient high‐fat diet with 0.1% methionine (CDAHFD) and then injected the CT26 cells to produce experimental metastasis. The number of metastatic tumours was significantly increased in mice with severe fatty liver as compared to control mice. The average size of metastatic tumours was smaller in mice with moderate fatty liver than in control mice. The stromal components, including cancer‐associated fibroblasts, tumour‐associated macrophages and tumour‐infiltrating lymphocytes, were also examined. Metastatic tumours in fatty liver showed invasive growth patterns without a fibrotic capsule. Compared to control groups, the polarization of macrophages and subtypes of tumour‐infiltrating lymphocytes differed depending on the extent of fatty liver progression. These results indicated that fatty changes in the liver influenced liver metastasis of CRC. Although moderate fatty changes suppress the growth of metastatic tumours in the liver, a severe fatty microenvironment may promote invasion and metastasis through alteration of the tumour microenvironment (TME).