Prognosis according to histochemical analysis of liver metastases removed at liver resection

Exploring immune status in peripheral blood and tumor tissue in association with survival in patients with multi-organ metastatic colorectal cancer

Colorectal cancer (CRC) raises considerable clinical challenges, including a high mortality rate once the tumor spreads to distant sites. At this advanced stage, more accurate prediction of prognosis and treatment outcome is urgently needed. The role of cancer immunity in metastatic CRC (mCRC) is poorly understood. Here, we explore cellular immune cell status in patients with multi-organ mCRC. We analyzed T cell infiltration in primary tumor sections, surveyed the lymphocytic landscape of liver metastases, and assessed circulating mononuclear immune cells. Besides asking whether immune cells are associated with survival at this stage of the disease, we investigated correlations between the different tissue types; as this could indicate a dominant immune phenotype. Taken together, our analyses corroborate previous observations that higher levels of CD8+ T lymphocytes link to better survival outcomes. Our findings therefore extend evidence from earlier stages of CRC to indicate an important role for cancer immunity in disease control even after metastatic spreading to multiple organs. This finding may help to improve predicting outcome of patients with mCRC and suggests a future role for immunotherapeutic strategies.

Vessel co-option: a unique vascular-immune niche in liver cancer

Tumor vasculature is pivotal in regulating tumor perfusion, immune cell infiltration, metastasis, and invasion. The vascular status of the tumor is intricately linked to its immune landscape and response to immunotherapy. Vessel co-option means that tumor tissue adeptly exploits pre-existing blood vessels in the para-carcinoma region to foster its growth rather than inducing angiogenesis. It emerges as a significant mechanism contributing to anti-angiogenic therapy resistance. Different from angiogenic tumors, vessel co-option presents a distinctive vascular-immune niche characterized by varying states and distribution of immune cells, including T-cells, tumor-associated macrophages, neutrophils, and hepatic stellate cells. This unique composition contributes to an immunosuppressive tumor microenvironment that is crucial in modulating the response to cancer immunotherapy. In this review, we systematically reviewed the evidence and molecular mechanisms of vessel co-option in liver cancer, while also exploring its implications for anti-angiogenic drug resistance and the immune microenvironment, to provide new ideas and clues for screening patients with liver cancer who are effective in immunotherapy.

Role of stromal PD-L1 expression in colorectal liver metastasis

BACKGROUND AND AIM

The outcomes of immune checkpoint blockade for colorectal cancer (CRC) treatment are unsatisfactory. Furthermore, the efficacy of immune checkpoint blockade for liver metastasis of various cancer is poor. Here, we investigated the relationship between stromal programmed death-ligand 1 (PD-L1) expression and the prognosis of patients with colorectal cancer liver metastasis (CRLM).

METHODS

The present study enrolled 84 CRLM patients who underwent surgery (R0) for CRC. Immunohistochemistry was performed to analyze stromal PD-L1 expression in CRLM.

RESULTS

Stromal PD-L1 was expressed in 52.3% of CRLM samples, which was associated with fewer not optimally resectable metastases (p = 0.04). Stromal PD-L1 also tended to associate with a lower tumor grade (p = 0.08). Stromal PD-L1-positive patients had longer overall survival (p = 0.003). Multivariate analysis identified stromal PD-L1 expression (p = 0.008) and poorer differentiation (p < 0.001) as independent prognostic indicators. Furthermore, stromal PD-L1 expression was correlated to a high number of tumor-infiltrating lymphocytes (TILs). Stromal PD-L1- and low TIL groups had shorter OS than stromal PD-L1 + and high TIL groups (46.6% vs. 81.8%, p = 0.05) Stromal PD-L1-positive patients had longer disease-free survival (DFS) (p = 0.03) and time to surgical failure (p = 0.001). Interestingly, stromal PD-L1 expression was positively related to the desmoplastic subtype (p = 0.0002) and inversely related to the replacement subtype of the histological growth pattern (p = 0.008).

CONCLUSIONS

Stromal PD-L1 expression may be a significant prognostic marker for CRLM.

Histopathological growth pattern evolution of tumor in VX2 liver cancer model

The histopathological growth pattern (HGP) is a morphological reflection of interactions between cancer cells and the surrounding tissue, and has been identified with a remarkably predictive value in liver metastases. However, there is still a lack of studies on HGP of primary liver cancer even furtherly on HGP evolution. We employed VX2 tumor-bearing rabbits as the primary liver cancer model of which tumor size and distant metastasis were investigated. HGP assessment and computed tomography scanning was performed in four cohorts of different time points to map the HGP evolution. Additionally, Fibrin deposition and neovascularization were evaluated by Masson staining and immunohistochemical analysis of CD31, hypoxia-inducible factor-1 alpha (HIF1A) and vascular endothelial growth factor (VEGF). Tumors displayed exponential growth in the VX2 liver cancer model, but these tumor-bearing animals did not show any visible metastasis until they reached a specific stage of development. Correspondingly, the components of HGPs changed along with the tumor growth. The proportion of desmoplastic HGP (dHGP) decreased initially and then grew, but in contrast, the level of replacement HGP (rHGP) rose from the 7th day, reached a peak at around the 21st day, and then appeared drop. Importantly, the collagen deposition and expression of HIF1A and VEGF correlated with dHGP, while CD31 did not. HGP evolution presents a two-way switch including dHGP to rHGP and rHGP to dHGP, in which the emergence of rHGP may be linked to metastases. HIF1A-VEGF partially participates in the HGP evolution and presumably plays a key role in the formation of dHGP.

Phenotypic Characterization of Colorectal Liver Metastases: Capsule versus No Capsule and the Potential Role of Epithelial Mesenchymal Transition

Background: Colorectal liver metastases (CRLM) can be encased in a fibrous capsule separating cancer from normal liver tissue, which correlates with increased patient survival. This study investigated the cellular and molecular components of capsule formation and the possible role of epithelial mesenchymal transition (EMT). Methods: From 222 patients with CRLM, 84 patients (37.8%) were categorized to have CRLM encased with a capsule. A total of 34 CRLM from 34 selected patients was analyzed in detail by EMT pathway-profiling and custom PCR arrays to identify differences in gene expression between CRLM with (n = 20) and without capsule (n = 14). In parallel, those 34 CRLM were used to analyze 16 gene products at the metastasis margin via immunohistochemistry. Results: Encapsulated CRLM showed an elevated expression of signal transduction pathways and effector molecules involved in EMT. E-cadherin and keratin-19 were more prevalent, and transcription as well as translation (immunohistochemistry) of pGSK-3-β, SOX10, tomoregulin-1, and caldesmon were increased. By contrast, the loss of E-cadherin and the prevalence of snail-1 were increased in CRLM without capsule. Collagen I and III and versican were identified as capsule components with extracellular matrix fibers running concentrically around the malignant tissue and parallel to the invasive front. Caldesmon was also demonstrated as a capsule constituent. Conclusions: The fibrous capsule around CRLM can be produced by cells with mesenchymal characteristics. It functions as a protective border by both the features of fiber architecture and the inhibition of invasive growth through EMT recruiting mesenchymal cells such as myofibroblasts by transformation of surrounding epithelial or even carcinoma cells. By contrast, EMT demonstrated in non-encapsulated CRLM may lead to a more mesenchymal, mobile, and tissue-destructive carcinoma cell phenotype and facilitate malignant spread.

Prognostic Significance of the Histopathological Growth Pattern and Tumor-Infiltrating Lymphocytes in Stratifying Survival After Hepatectomy for Colorectal Liver Metastases

BACKGROUND

A histopathological growth pattern (HGP) occurs at the interface between tumor cells and the surrounding liver parenchyma. Desmoplastic HGP (dHGP) is associated with a favorable prognosis and shows denser infiltration of lymphocytes than other HGPs. Tumor-infiltrating lymphocytes (TILs) exert antitumor immunity, nonetheless, their prognostic significance in patients with dHGP is unknown. This study aimed to identify the prognostic significance of HGP and TILs in colorectal liver metastasis (CRLM).

METHODS

The study analyzed 140 patients who underwent hepatectomy for CRLM. Depending on the type of HGP and TIL, the patients were categorized into four groups (dHGP/high TIL, dHGP/low TIL, non-dHGP/high TIL, and non-dHGP/low TIL) for a comparison of their recurrence-free survival (RFS) and overall survival (OS). Uni- and multivariate analyses were performed using a Cox proportional hazards model.

RESULTS

The RFS and OS curves differed significantly between the groups. The multivariate analysis showed that a combination of HGP and TIL could stratify the recurrence and survival outcomes.

CONCLUSION

This study indicated that a combination of HGP and TIL can stratify the risk of survival after hepatectomy in patients with CRLM.

The relationship between primary colorectal cancer histology and the histopathological growth patterns of corresponding liver metastases

Background

The histopathological growth patterns (HGPs) are a prognostic and predictive biomarker in colorectal cancer liver metastasis (CRLM). This study evaluates the relationship between the HGP and primary colorectal cancer (CRC) histopathology.

Methods

A total of 183 treatment-naive patients with resected CRC and CRLM were included. Thirteen CRC histopathology markers were determined and compared between the desmoplastic and non-desmoplastic HGP; tumour sidedness, pT&pN stage, tumour grade, tumour deposits, perineural- (lympho-)vascular- and extramural venous invasion, peritumoural budding, stroma type, CRC growth pattern, Crohn’s-like lymphoid reaction, and tumour-infiltrating lymphocyte (TIL) density. Logistic regression analysis was performed using both CRC and CRLM characteristics.

Results

Unfavourable CRC histopathology was more frequent in non-desmoplastic CRLM for all markers evaluated, and significantly so for a lower TIL density, absent Crohn’s-like lymphoid reaction, and a “non-mature” stroma (all p < 0.03). The cumulative prevalence of unfavourable CRC histopathology was significantly higher in patients with non-desmoplastic compared to desmoplastic CRLM, with a median (IQR) of 4 (3–6) vs 2 (1–3.5) unfavourable characteristics observed, respectively (p < 0.001). Multivariable regression with 9 CRC histopathology markers and 2 CRLM characteristics achieved good discriminatory performance (AUC = 0.83).

Conclusions

The results of this study associates primary CRC histopathology with the HGP of corresponding liver metastases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09994-3.

Clinical implications and mechanism of histopathological growth pattern in colorectal cancer liver metastases

Liver is the most common site of metastases of colorectal cancer, and liver metastases present with distinct histopathological growth patterns (HGPs), including desmoplastic, pushing and replacement HGPs and two rare HGPs. HGP is a miniature of tumor-host reaction and reflects tumor biology and pathological features as well as host immune dynamics. Many studies have revealed the association of HGPs with carcinogenesis, angiogenesis, and clinical outcomes and indicates HGP functions as bond between microscopic characteristics and clinical implications. These findings make HGP a candidate marker in risk stratification and guiding treatment decision-making, and a target of imaging observation for patient screening. Of note, it is crucial to determine the underlying mechanism shaping HGP, for instance, immune infiltration and extracellular matrix remodeling in desmoplastic HGP, and aggressive characteristics and special vascularization in replacement HGP (rHGP). We highlight the importance of aggressive features, vascularization, host immune and organ structure in formation of HGP, hence propose a novel "advance under camouflage" hypothesis to explain the formation of rHGP.

A Comprehensive Prognostic Model for Colorectal Cancer Liver Metastasis Recurrence After Neoadjuvant Chemotherapy

Background

For patients with colorectal cancer liver metastases (CRLMs), it is important to stratify patients according to the risk of recurrence. This study aimed to validate the predictive value of some clinical, imaging, and pathology biomarkers and develop an operational prognostic model for patients with CRLMs with neoadjuvant chemotherapy (NACT) before the liver resection.

Methods

Patients with CRLMs accompanied with primary lesion and liver metastases lesion resection were enrolled into this study. A nomogram based on independent risk factors was identified by Kaplan–Meier analysis and multivariate Cox proportional hazard analysis. The predictive ability was evaluated by receiver operating characteristic (ROC) curves and decision curve analysis (DCA). Calibration plot were also used to explore the consistency between prediction and reality.

Results

A total of 118 patients were enrolled into the study. Multivariable Cox analysis found that histopathological growth patterns (HGPs) [Hazard Rate (HR) = 2.130], radiology response (stable disease vs. partial response, HR = 2.207; progressive disease vs. partial response, HR = 3.824), lymph node status (HR = 1.442), and age (HR = 0.576) were independent risk factors for disease-free survival (DFS) (p < 0.05). Corresponding nomogram was constructed on the basis of the above factors, demonstrating that scores ranging from 5 to 11 presented better prognosis than the scores of 0–4 (median DFS = 14.3 vs. 4.9 months, p < 0.0001). The area under ROC curves of the model for 1-, 2-, and 3-year DFS were 0.754, 0.705, and 0.666, respectively, and DCA confirmed that the risk model showed more clinical benefits than clinical risk score. Calibration plot for the probability of DFS at 1 or 3 years verified an optimal agreement between prediction and actual observation. In the course of our research, compared with pure NACT, a higher proportion of desmoplastic HGP (dHGP) was detected in patients treated with NACT plus cetuximab (p = 0.030), and the use of cetuximab was an independent factor for decreased replacement HGP (rHGP) and increased dHGP (p = 0.049).

Conclusion

Our model is concise, comprehensive, and high efficient, which may contribute to better predicting the prognosis of patients with CRLMs with NACT before the liver resection. In addition, we observed an unbalanced distribution of HGPs as well.

Histopathological growth patterns modify the prognostic impact of microvascular invasion in non-cirrhotic hepatocellular carcinoma

BACKGROUND

Microvascular invasion (MVI) is an established prognosticator in hepatocellular carcinoma (HCC). Histopathological growth patterns (HGPs) classify the invasive margin of hepatic tumors, with superior survival observed for the desmoplastic HGP. Our aim was to investigate non-cirrhotic HCC in light of MVI and the HGP.

METHODS

A retrospective cohort study was performed in resected non-cirrhotic HCC. MVI was assessed prospectively. The HGP was determined retrospectively, blinded, and according to guidelines. Overall and disease-free survival (OS, DFS) were evaluated by Kaplan-Meier and multivariable Cox regression.

RESULTS

The HGP was determined in 155 eligible patients, 55 (35%) featured a desmoplastic HGP. MVI was observed in 92 (59%) and was uncorrelated with HGP (64% vs 57%, p = 0.42). On multivariable analysis, non-desmoplastic and MVI-positive were associated with an adjusted HR [95%CI] of 1.61 [0.98-2.65] and 3.22 [1.89-5.51] for OS, and 1.59 [1.05-2.41] and 2.30 [1.52-3.50] for DFS. Effect modification for OS existed between HGP and MVI (p < 0.01). Non-desmoplastic MVI-positive patients had a 5-year OS of 36% (HR: 5.21 [2.68-10.12]), compared to 60% for desmoplastic regardless of MVI (HR: 2.12 [1.08-4.18]), and 86% in non-desmoplastic MVI-negative.

CONCLUSION

HCCs in non-cirrhotic livers display HGPs which may be of prognostic importance, especially when combined with MVI.

Histopathological factors versus margin size in single colorectal liver metastases: Does a 1-cm margin size matter?

Background and objective:

The ideal margin width for surgical resection of colorectal liver metastases has been extensively studied, but not sufficiently in accordance with other pathological factors. The aim of this study was to assess for the first time the prognostic impact of margin widths according to different prognostic pathological factors in colorectal liver metastasis.

Methods:

We evaluated 101 patients with a single resected metastasis. Slides stained by HE were assessed for the presence of poorly differentiated clusters, peritumoral inflammatory infiltrate, tumor pseudocapsule, and tumor borders pattern. Overall survival, disease-free survival, and hepatic recurrence were evaluated. The pathologic factors prognostic impact was evaluated according to a (< or ⩾) 10-mm margin size.

Results:

Factors independently associated with a shorter overall survival were absence of tumor pseudocapsule ( p < 0.001) and infiltrative tumor border pattern ( p = 0.019). The absence of tumor pseudocapsule was the only factor independently associated with shorter disease-free survival ( p < 0.001). Hepatic recurrence was associated with infiltrative tumor border and absence of pseudocapsule. Margin width ⩾10 mm did not impact overall survival independently of the studied histological prognostic factors.

Conclusions:

In colorectal liver metastasis resection, the absence of tumor pseudocapsule was significantly associated with shorter overall survival and disease-free survival and hepatic recurrence. However, margins larger than 10 mm did not offer survival benefit when other pathologic negative prognostic factors were concomitantly analyzed, reinforcing the idea that biology, rather than margin size, is crucial for prognosis.

Spatial Immunology in Liver Metastases from Colorectal Carcinoma according to the Histologic Growth Pattern

Simple Summary

In the era of immunotherapy, the tumor microenvironment (TME) has attracted special interest. However, colorectal liver metastases (CRC-LM) present histological peculiarities that could affect the interaction of immune and tumor cells such as fibrotic encapsulation and dense intratumoral stroma. We explored the spatial distribution of lymphocytic infiltrates in CRC-LM in the context of the histologic growth patterns using multispectral digital pathology providing data on three different scenarios, tumor periphery, invasive margin, and central tumoral areas. Our results illustrate a similar poor cell density of CD8⁺ cells between different metastases subtypes in intratumoral regions. However, in encapsulated metastases, cytotoxic cells reach the tumor cells while remaining retained in stromal areas in non-encapsulating metastases. Some aspects are still unresolved, such as understanding the reason why most lymphocytes are largely retained in the capsule.

Abstract

Colorectal cancer liver metastases (CRC-LM) present differential histologic growth patterns (HGP) that determine the interaction between immune and tumor cells. We explored the spatial distribution of lymphocytic infiltrates in CRC-LM in the context of the HGP using multispectral digital pathology. We did not find statistically significant differences of immune cell densities in the central regions of desmoplastic (_dHGP) and non-desmoplastic (_ndHGP) metastases. The spatial evaluation reported that _dHGP-metastases displayed higher infiltration by CD8⁺ and CD20⁺ cells in peripheral regions as well as CD4⁺ and CD45RO⁺ cells in _ndHGP-metastases. However, the reactive stroma regions at the invasive margin (IM) of _ndHGP-metastases displayed higher density of CD4⁺, CD20⁺, and CD45RO⁺ cells. The antitumor status of the TIL infiltrates measured as CD8/CD4 reported higher values in the IM of encapsulated metastases up to 400 μm towards the tumor center (p < 0.05). Remarkably, the IM of _dHGP-metastases was characterized by higher infiltration of CD8⁺ cells in the epithelial compartment parameter assessed with the ratio CD8^epithelial/CD8^stromal, suggesting anti-tumoral activity in the encapsulating lesions. Taking together, the amount of CD8⁺ cells is comparable in the IM of both HGP metastases types. However, in _dHGP-metastases some cytotoxic cells reach the tumor nests while remaining retained in the stromal areas in _ndHGP-metastases.

Prognostic role of tumour-infiltrating lymphocytes and macrophages in relation to MSI, CDX2 and BRAF status: a population-based study of metastatic colorectal cancer patients

BACKGROUND

Tumour-infiltrating CD3, CD8 lymphocytes and CD68 macrophages are associated with favourable prognosis in localised colorectal cancer, but the effect in metastatic colorectal cancer (mCRC) is not established.

METHODS

A Scandinavian population-based cohort of non-resectable mCRC patients was studied. Tissue microarrays (n = 460) were stained with CD3, CD8 and CD68 using fluorescence-based multiplex immunohistochemistry. Associations with clinicopathological variables, overall survival (OS) and progression-free survival were estimated.

RESULTS

Two-thirds of microsatellite instable (MSI) and one-fourth of microsatellite stable (MSS) tumours displayed the highest quartile density of CD8. For CD3 high vs low cases, median OS was 20 vs 16 months (HR: 0.76, 95% CI: 0.59, 0.76, p = 0.025) with 3-year OS of 27 vs 13%. For CD68 high vs low cases, median OS was 23 vs 15 months (HR: 0.69, 95% CI: 0.54, 0.88, p = 0.003) with 3-year OS of 28 vs 12%. MSI, BRAF mutation and CDX2 loss were negative prognostic markers independent of tumour immune infiltration.

CONCLUSIONS

In mCRC, high lymphocyte infiltration was found in proportions of MSI and MSS tumours-potential subgroups of immunotherapy response. Tumour-infiltrating CD3 lymphocytes and CD68 macrophages were associated with median and long-term survival. MSI was a significant negative prognostic marker despite high immunogenicity.

Delayed MRI Enhancement of Colorectal Cancer Liver Metastases Is Associated With Metastatic Mutational Profile

BACKGROUND/AIM

Individual tumor genomics plays a key role in determining patient prognosis, response to chemotherapy and in guiding therapy. In prior studies, it was shown that the degree of late enhancement of colorectal liver metastases (CRCLM) target tumor enhancement (TTE) as seen on magnetic resonance imaging (MRI) was associated with overall survival. In order to better understand the relationship between MRI enhancement and survival, the aim of this study was to characterize genomic profiles of tumors clustered by MRI TTE, and investigate the association between TTE and genetic mutations.

MATERIALS AND METHODS

Matched tumor and normal tissue samples from patients with weak TTE and strong TTE were analyzed by Next-generation sequencing (NGS) technology using a custom colorectal cancer panel.

RESULTS

We discovered a total of 42 non-synonymous somatic mutations from 10 patients with weak TTE and 26 with 10 patients with strong TTE. Adenomatosis Polyposis Coli (APC) was the most commonly altered gene, 18 of those APC mutations were found in the weak TTE and 9 in the strong TTE group.

CONCLUSION

An association exists between TTE and mutational status of CRCLM, which may offer some explanation as to why TTE is associated with overall survival in patients with CRCLM.

Preoperative systemic chemotherapy alters the histopathological growth patterns of colorectal liver metastases

Histopathological growth patterns (HGPs) are a reliable, reproducible, and strong prognostic biomarker that can be assessed on haematoxylin and eosin-stained sections of resected colorectal liver metastases (CRLM). Assessment estimates the relative fraction of the tumour-liver interface for each of the three growth patterns; the desmoplastic HGP reflects good prognosis. Whether preoperative chemotherapy affects the HGP is currently unclear. The present international multicentre study evaluates this in an original cohort of 877 consecutive patients treated in the Netherlands, an external validation cohort of 1,203 consecutive patients treated in the USA, and a post hoc analysis from the phase III randomised controlled European Organization for Research and Treatment of Cancer (EORTC) 40983 trial (n = 70). All patients underwent resection of CRLM with or without preoperative systemic chemotherapy. Trial patients were randomised between perioperative chemotherapy and resection or resection alone. HGPs were determined according to consensus guidelines and compared for preoperative treatment status. Data from three separate tumour regression grading systems were available for the trial cohort. These were correlated with HGP stratified for treatment arm. In the original cohort, the average presence of desmoplastic HGP was 43% for chemo-naïve versus 67% for preoperatively treated patients (p < 0.001). A significant association between chemotherapy and desmoplastic HGP was found on multivariable analysis (β [95% confidence interval, CI]: 24.57 [18.28-30.87], p < 0.001). In the validation cohort, the average presence of desmoplastic HGP was 40% for chemo-naïve versus 63% for preoperatively treated patients (p < 0.001). This association remained on multivariable analysis (β [95% CI]: 24.18 [18.70-29.66], p < 0.001). In the EORTC 40983 trial, the average desmoplastic HGP presence was 33% in the resection arm versus 61% in the chemotherapy arm (p = 0.005). Chemotherapy was independently associated with an increase in desmoplastic HGP (β [95% CI]: 23.29 [1.78-44.79], p = 0.022). All three tumour regression gradings were significantly associated with the desmoplastic HGP in the chemotherapy arm (all p < 0.04). None were associated in the resection arm (all p > 0.11). Preoperative chemotherapy induces histopathological changes that alter the HGP of CRLM.

Histological tumor response to neoadjuvant chemotherapy correlates to Immunoscore in colorectal cancer liver metastases patients

BACKGROUND

This study investigated the correlation between tumor regression grade (TRG) score and Immunoscore, and prognostic values of TRG score and a risk score in colorectal cancer liver metastases (CRLMs) patients after neoadjuvant chemotherapy.

METHODS

Patients undergoing neoadjuvant chemotherapy from 2014 to 2019 were selected. TRG score and Immunoscore were evaluated in 200 CRLMs. A risk score combining TRG score, Immunoscore, and clinical risk score (CRS) was defined and divided patients into the low-, medium-, and high-risk groups. Differences in relapse-free survival (RFS) and overall survival (OS) between groups were determined.

RESULTS

The densities of CD3⁺ and CD8⁺ immune cells were higher in TRG1-3 group than in TRG4-5 group, and the ratio of high Immunoscores was higher in TRG1-3 group than in TRG4-5 group (60.0% vs. 15.8%, p < 0.001). Patients in TRG1-3 group had significantly longer RFS and OS than those in TRG4-5 group. The low-risk group shows a significantly higher 2-year RFS and 5-year OS rate than the medium- and high-risk group (RFS: 59.9%, 36.2%, and 6.4%, p < 0.001; OS: 82.0%, 41.0%, and 16.9%, p < 0.001).

CONCLUSION

TRG score may be proposed to evaluate the prognosis of neoadjuvant chemotherapy and may be used for predicting the postoperative survival of CRLMs.

Infiltrative tumour growth pattern correlates with poor outcome in oesophageal cancer

Objective

Oesophageal cancer (OEC) is an aggressive disease with a poor survival rate. Prognostic markers are thus urgently needed. Due to the demonstrated prognostic value of histopathological growth pattern (HGP) in other cancers, we performed a retrospective assessment of HGP in patients suffering from invasive OEC.

Design

A first cohort composed of 89 treatment-naïve operated patients with OEC from The Cancer Genome Atlas (TCGA) public database was constituted, from which H&E images and RNA-sequencing data were retrieved. Next, a second cohort composed of 99 patients with OEC treated and operated in a Belgian hospital was established. H&E-stained sections and extracted tumorous RNA were obtained from the samples. HGP were assessed on H&E slides as infiltrative (IGP) or expansive (EGP). TCGA RNA-sequencing data were analysed through the gene set enrichment analysis and Cytoscape softwares. Real-time quantitative PCR (qPCR) experiments were performed to assess gene expression in the Belgian cohort.

Results

IGP patients displayed a grim prognosis compared with EGP patients, while IGP was found as associated with numerous lymphovascular emboli and perinervous infiltrations. Analyses of the TCGA expression data showed that angiogenesis, epithelial-to-mesenchymal transition (EMT) and inflammation were significantly upregulated in IGP compared with EGP samples. qPCR experiments of three genes appearing as highly upregulated in each pathway showed no difference in expression according to the HGP.

Conclusion

The current study demonstrates the poor prognostic value carried by IGP in OC and suggests angiogenesis, EMT and inflammation as key carcinogenetic pathways upregulated in this pattern.

Liver Immune Microenvironment and Metastasis from Colorectal Cancer-Pathogenesis and Therapeutic Perspectives

A drastic difference exists between the 5-year survival rates of colorectal cancer patients with localized cancer and distal organ metastasis. The liver is the most favorable organ for cancer metastases from the colorectum. Beyond the liver-colon anatomic relationship, emerging evidence highlights the impact of liver immune microenvironment on colorectal liver metastasis. Prior to cancer cell dissemination, hepatocytes secrete multiple factors to recruit or activate immune cells and stromal cells in the liver to form a favorable premetastatic niche. The liver-resident cells including Kupffer cells, hepatic stellate cells, and liver-sinusoidal endothelial cells are co-opted by the recruited cells, such as myeloid-derived suppressor cells and tumor-associated macrophages, to establish an immunosuppressive liver microenvironment suitable for tumor cell colonization and outgrowth. Current treatments including radical surgery, systemic therapy, and localized therapy have only achieved good clinical outcomes in a minority of colorectal cancer patients with liver metastasis, which is further hampered by high recurrence rate. Better understanding of the mechanisms governing the metastasis-prone liver immune microenvironment should open new immuno-oncology avenues for liver metastasis intervention.

Histopathological Growth Patterns and Survival After Resection of Colorectal Liver Metastasis: An External Validation Study

Background

After resection of colorectal cancer liver metastases (CRLM), 2 main histopathological growth patterns can be observed: a desmoplastic and a nondesmoplastic subtype. The desmoplastic subtype has been associated with superior survival. These findings require external validation.

Methods

An international multicenter retrospective cohort study was conducted in patients treated surgically for CRLM at 3 tertiary hospitals in the United States and the Netherlands. Determination of histopathological growth patterns was performed on hematoxylin and eosin-stained sections of resected CRLM according to international guidelines. Patients displaying a desmoplastic histopathological phenotype (only desmoplastic growth observed) were compared with patients with a nondesmoplastic phenotype (any nondesmoplastic growth observed). Cutoff analyses on the extent of nondesmoplastic growth were performed. Overall survival (OS) and disease-free survival (DFS) were estimated using Kaplan-Meier and multivariable Cox analysis. All statistical tests were 2-sided.

Results

In total 780 patients were eligible. A desmoplastic phenotype was observed in 19.1% and was associated with microsatellite instability (14.6% vs 3.6%, P = .01). Desmoplastic patients had superior 5-year OS (73.4%, 95% confidence interval [CI] = 64.1% to 84.0% vs 44.2%, 95% CI = 38.9% to 50.2%, P < .001) and DFS (32.0%, 95% CI = 22.9% to 44.7% vs 14.7%, 95% CI = 11.7% to 18.6%, P < .001) compared with their nondesmoplastic counterparts. A desmoplastic phenotype was associated with an adjusted hazard ratio for death of 0.36 (95% CI = 0.23 to 0.58) and 0.50 (95% CI = 0.37 to 0.66) for cancer recurrence. Prognosis was independent of KRAS and BRAF status. The cutoff analyses found no prognostic relationship between either OS or DFS and the extent of nondesmoplastic growth observed (all P > .1).

Conclusions

This external validation study confirms the remarkably good prognosis after surgery for CRLM in patients with a desmoplastic phenotype. The extent of nondesmoplastic growth does not affect prognosis.

Histopathological and Immune Prognostic Factors in Colo-Rectal Liver Metastases

Simple Summary

Clinical management of colo-rectal liver metastasis would benefit from a refined stratification of patients in prognostic groups, in order to identify the best therapeutic option. Efforts are ongoing in the definition of parameters associated with clinical behaviors, which could help classifying patients in clinically relevant groups. Here we aimed at discussing the recent advances in this field, and we introduced current and new promising candidates, such as morphological tumor features and immune components, which have been showing significant association with survival. Some of these parameters are slowly reaching the clinic and further efforts are ongoing in the attempt to combine them in multiparametric scores.

Abstract

Prognostic studies are increasingly providing new tools to stratify colo-rectal liver metastasis patients into clinical subgroups, with remarkable implications in terms of clinical management and therapeutic choice. Here, the strengths and hurdles of current prognostic tools in colo-rectal liver metastasis are discussed. Alongside more classic histopathological parameters, which capture features related to the tumor component, such as tumor invasion, tumor growth pattern and regression score, we will discuss immune mediators, which are starting to be considered important features. Their objective quantification has shown significant results in prognostication studies, with most of the work focused on adaptive immune cells, namely T cells. As for macrophages, they are only starting to be appreciated and we will present recent advances in evaluation of macrophage morphological features. Deeper knowledge acquired by multiparametric analyses is rapidly uncovering the variety of immune players that should be assessed. The future projection is to implement deep-learning histopathological tools and to integrate histopathological and immune metrics in multiparametric scores, with the ultimate objective to achieve a deeper resolution of the tumor features and their relevance for colo-rectal liver metastasis.

The Tumor Microenvironment in Liver Metastases from Colorectal Carcinoma in the Context of the Histologic Growth Patterns

Colorectal carcinoma (CRC) is the third most common cancer. Likewise, it is a disease that has a long survival if it is prematurely detected. However, more than 50% of patients will develop metastases, mainly in the liver (LM-CRC), throughout the evolution of their disease, which accounts for most CRC-related deaths. Treatment it is certainly a controversial issue, since it has not been shown to increase overall survival in the adjuvant setting, although it does improve disease free survival (DFS). Moreover, current chemotherapy combinations are administered based on data extrapolated from primary tumors (PT), not considering that LM-CRC present a very particular tumor microenvironment that can radically condition the effectiveness of treatments designed for a PT. The liver has a particular histology and microenvironment that can determine tumor growth and response to treatments: double blood supply, vascularization through fenestrated sinusoids and the presence of different mesenchymal cell types, among other particularities. Likewise, the liver presents a peculiar immune response against tumor cells, a fact that correlates with the poor response to immunotherapy. All these aspects will be addressed in this review, putting them in the context of the histological growth patterns of LM-CRC, a particular pathologic feature with both prognostic and predictive repercussions.

Histopathological prognostic factors for colorectal liver metastases: A systematic review and meta-analysis of observational studies

INTRODUCTION

Resection is the mainstay of treatment for colorectal liver metastases (CRLMs). Many different histopathological factors related to the primary colorectal tumour have been well studied; however, histopathological prognostic factors related to CRLMs are still under evaluation.

OBJECTIVE

To identify histopathological factors related to overall survival (OS) and disease-free survival (DFS) in patients with resected CRLMs.

METHODS

A systematic review was performed with the following databases up to August 2020: PubMed, EMBASE, Web of Science, SciELO, and LILACS. The GRADE approach was used to rate the overall certainty of evidence by outcome.

RESULTS

Thirty-three studies including 4,641 patients were eligible. We found very low certainty evidence that the following histopathological prognostic factors are associated with a statistically significant decrease in OS: presence of portal vein invasion (HR, 0,50 [95% CI, 0,37 to 0,68]; I²=0%), presence of perineural invasion (HR, 0,55 [95% CI, 0,36 to 0,83]; I²=0%), absence of pseudocapsule (HR, 0,41 [CI 95%, 0,29 to 0,57], p<0,00001; I²=0%), presence of satellite nodules (OR, 0,45 [95% CI, 0,26 to 0,80]; I²=0%), and the absence of peritumoural inflammatory infiltrate (OR, 0,20 [95% CI, 0,08 to 0,54]; I²=0%). Outcome data on DFS were scarce, except for tumour borders, which did not present a significant impact, precluding the meta-analysis.

CONCLUSION

Of the histopathological prognostic factors studied, low- to moderate-certainty evidence shows that vascular invasion, perineural invasion, absence of pseudocapsule, presence of satellite nodules, and absence of peritumoral inflammatory infiltrate are associated with shorter overall survival in CRLMs.

Immune scores in colorectal cancer: Where are we?

There is growing evidence that the immune system may prevent the occurrence, growth and metastatic diffusion of colorectal cancer (CRC). The role played by the adaptive immune response at the tumour site is critical in the balance between tumour invasion and defence against cancer. Recent data have shown that the evaluation of this immune response may help to define the prognosis and possibly the treatment of localised CRC as well as metastatic CRC. Tumour infiltrates with T cells (CD3+), cytotoxic T cells (CD8+) and memory T cells (CD45RO+) are the immune parameters most consistently and strongly associated with good clinical outcome in CRC. Several scoring systems have been developed, including the Immunoscore®, based on the immunohistochemical determination with a digital image analysis system of the density of CD3+ and CD8+ lymphocytes in the centre and the invasive margin of the tumour. This review will focus on the different immunoscoring systems developed in CRC, their performance, their limitations and their potential for improving patients' care in the future.

Enrichment of the tumour immune microenvironment in patients with desmoplastic colorectal liver metastasis

BACKGROUND

Patients with resected colorectal liver metastasis (CRLM) who display only the desmoplastic histopathological growth pattern (dHGP) exhibit superior survival compared to patients with any non-desmoplastic growth (non-dHGP). The aim of this study was to compare the tumour microenvironment between dHGP and non-dHGP.

METHODS

The tumour microenvironment was investigated in three cohorts of chemo-naive patients surgically treated for CRLM. In cohort A semi-quantitative immunohistochemistry was performed, in cohort B intratumoural and peritumoural T cells were counted using immunohistochemistry and digital image analysis, and in cohort C the relative proportions of individual T cell subsets were determined by flow cytometry.

RESULTS

One hundred and seventeen, 34, and 79 patients were included in cohorts A, B, and C, with dHGP being observed in 27%, 29%, and 15% of patients, respectively. Cohorts A and B independently demonstrated peritumoural and intratumoural enrichment of cytotoxic CD8+ T cells in dHGP, as well as a higher CD8+/CD4+ ratio (cohort A). Flow cytometric analysis of fresh tumour tissues in cohort C confirmed these results; dHGP was associated with higher CD8+ and lower CD4+ T cell subsets, resulting in a higher CD8+/CD4+ ratio.

CONCLUSION

The tumour microenvironment of patients with dHGP is characterised by an increased and distinctly cytotoxic immune infiltrate, providing a potential explanation for their superior survival.

Histopathological growth patterns correlate with the immunoscore in colorectal cancer liver metastasis patients after hepatectomy

Various scoring systems have been proposed to predict the postoperative prognosis of colorectal liver metastasis (CRLM), including the clinical risk score (CRS), the immunoscore and so on. Recently, histopathological growth patterns (HGPs) have been recognized. However, the correlation between HGPs and the immunoscore, and their prognostic values in patients with CRLM after liver resection remain undetermined. In this study, HGPs were retrospectively evaluated in H&E-stained slides from 166 CRLM patients. The immunoscore was calculated according to the densities of immunostained CD3 + and CD8 + cells. A risk score combining HGPs, the immunoscore and the CRS was defined and divided patients into the low-, medium- and high-risk group. Our results showed that the densities of CD3 + and CD8 + cells were higher in the desmoplastic HGP (dHGP) group than in the non-dHGP group, and the proportion of high immunoscores was also higher in the dHGP group (51.9% vs. 33.0%, respectively, P = 0.020). Patients with the dHGP had significantly longer relapse-free survival (RFS) and overall survival (OS) than those with the non-HGP. The low-risk group showed significantly higher 2-year RFS and 5-year OS rates than the other two groups (RFS: 76.2%, 43.7% and 33.1%, respectively; P < 0.001; OS: 89.7%, 54.4% and 33.3%, respectively; P < 0.001). In conclusion, the dHGP correlates with relatively high immunoscores, predicting a favorable prognosis independent of the immunoscore and CRS. A novel risk score combining HGPs, the immunoscore and the CRS may be used for the stratification of CRLM patients' survival.

Histopathological growth patterns and positive margins after resection of colorectal liver metastases

BACKGROUND

Histopathological growth patterns (HGPs) of colorectal liver metastases (CRLM) may be an expression of biological tumour behaviour impacting the risk of positive resection margins. The current study aimed to investigate whether the non-desmoplastic growth pattern (non-dHGP) is associated with a higher risk of positive resection margins after resection of CRLM.

METHODS

All patients treated surgically for CRLM between January 2000 and March 2015 at the Erasmus MC Cancer Institute and between January 2000 and December 2012 at the Memorial Sloan Kettering Cancer Center were considered for inclusion.

RESULTS

Of all patients (n = 1302) included for analysis, 13% (n = 170) had positive resection margins. Factors independently associated with positive resection margins were the non-dHGP (odds ratio (OR): 1.79, 95% confidence interval (CI): 1.11-2.87, p = 0.016) and a greater number of CRLM (OR: 1.15, 95% CI: 1.08-1.23 p < 0.001). Both positive resection margins (HR: 1.41, 95% CI: 1.13-1.76, p = 0.002) and non-dHGP (HR: 1.57, 95% CI: 1.26-1.95, p < 0.001) were independently associated with worse overall survival.

CONCLUSION

Patients with non-dHGP are at higher risk of positive resection margins. Despite this association, both positive resection margins and non-dHGP are independent prognostic indicators of worse overall survival.

Immune phenotype and histopathological growth pattern in patients with colorectal liver metastases

Background

Patients with desmoplastic (angiogenic) histopathological growth pattern (HGP) colorectal liver metastases (CLM) might derive more benefit from bevacizumab-based chemotherapy than those with replacement (non-angiogenic) HGP. This study investigated the association of HGP with the immune phenotype (IP) and clinical outcome after liver resection.

Methods

CLM of patients treated with perioperative bevacizumab-based chemotherapy and liver resection were investigated. Association of HGP and IP with response, recurrence-free survival (RFS) and overall survival (OS) was investigated.

Results

One hundred and eighteen patients (M/F 66/52, median age 62.3 (31.0–80.4) years, median follow-up 32.2 (5.0–92.7) months) were enrolled. The inflamed IP was associated with the desmoplastic HGP. The desmoplastic HGP was associated with better radiological and histological response compared to the replacement HGP, respectively. The replacement HGP was associated with shorter RFS (8.7 versus 16.3 months, HR 2.60, P = 0.001) and OS (36.6 months versus not reached, HR 2.32, P = 0.027), respectively. The non-inflamed IP was associated with shorter RFS (10.8 versus 16.5 months, HR 1.85, P = 0.029). The HGP but not the IP remained significant in multivariable analysis for RFS.

Conclusions

The desmoplastic HGP is associated with the inflamed IP and HGP may be a potential biomarker for adjuvant treatment that includes targeting the immune contexture.

B Cells as Prognostic Biomarker After Surgery for Colorectal Liver Metastases

Background: The aim of this study was to identify more accurate variables to improve prognostication of individual patients with colorectal liver metastases (CRLM). Clinicopathological characteristics only partly explain the large range in survival rates. Methods: MessengerRNA expression profiles of resected CRLM of two patient groups were analysed by mRNA sequencing: poor survivors (death from recurrent disease <30 months after surgery) and good survivors (no recurrent disease >60 months after surgery). Tumour and adjacent liver parenchyma samples were analysed. Results: MessengerRNA expression profiling of the tumour samples identified 77 genes that were differentially expressed between the two survival groups at a False Discovery Rate (FDR) <0.1. In the adjacent liver parenchyma samples only one gene, MTRNR2L1, showed significantly higher expression in the good survivors. Pathway analysis showed higher expression of immune-related and stroma-related genes in tumour samples from good survivors. Expression data was then validated by immunohistochemistry in two cohorts comprising a total of 125 patients. Immunohistochemical markers that showed to be associated with good survival in the total cohort were: high K/L+ infiltration in tumour stroma [p = 0.029; OR 2.500 (95% CI 1.100-5.682)] and high CD79A+ infiltration in tumour stroma [p = 0.036; OR 2.428 (95%CI 1.062-5.552)]. Conclusions: A high stromal infiltration of CD79A+ B cells and K/L+ plasma cells might be favourable prognostic biomarkers after surgery for CRLM.

Vessel co-option in cancer

All solid tumours require a vascular supply in order to progress. Although the ability to induce angiogenesis (new blood vessel growth) has long been regarded as essential to this purpose, thus far, anti-angiogenic therapies have shown only modest efficacy in patients. Importantly, overshadowed by the literature on tumour angiogenesis is a long-standing, but continually emerging, body of research indicating that tumours can grow instead by hijacking pre-existing blood vessels of the surrounding nonmalignant tissue. This process, termed vessel co-option, is a frequently overlooked mechanism of tumour vascularization that can influence disease progression, metastasis and response to treatment. In this Review, we describe the evidence that tumours located at numerous anatomical sites can exploit vessel co-option. We also discuss the proposed molecular mechanisms involved and the multifaceted implications of vessel co-option for patient outcomes.

Salvage treatment for recurrences after first resection of colorectal liver metastases: the impact of histopathological growth patterns

The majority of patients recur after resection of colorectal liver metastases (CRLM). Patients with CRLM displaying a desmoplastic histopathological growth pattern (dHGP) have a better prognosis and lower probability of recurrence than patients with non-dHGP CRLM. The current study evaluates the impact of HGP type on the pattern and treatment of recurrences after first resection of CRLM. A retrospective cohort study was performed, including patients with known HGP type after complete resection of CRLM. All patients were treated between 2000 and 2015. The HGP was determined on the CRLM resected at first partial hepatectomy. The prognostic value of HGPs, in terms of survival outcome, in the current patient cohort were previously published. In total 690 patients were included, of which 492 (71%) developed recurrent disease. CRLM displaying dHGP were observed in 103 patients (21%). Amongst patients with dHGP CRLM diagnosed with recurrent disease, more liver-limited recurrences were seen (43% vs. 31%, p = 0.030), whereas patients with non-dHGP more often recurred at multiple locations (34% vs. 19%, p = 0.005). Patients with dHGP CRLM were more likely to undergo curatively intended local treatment for recurrent disease (adjusted odds ratio: 2.37; 95% confidence interval (CI) [1.46-3.84]; p < 0.001) compared to patients with non-dHGP. The present study demonstrates that liver-limited disease recurrence after complete resection of CRLM is more often seen in patients with dHGP, whereas patients with non-dHGP more frequently experience multi-organ recurrence. Recurrences in patients with dHGP at first CRLM resection are more likely to be salvageable by local treatment modalities, but no prognostic impact of HGPs after salvage therapy for recurrent disease was found.

Systematic Review of the Prognostic Role of the Immune System After Surgery of Colorectal Liver Metastases

Background: The current prognostication of patient survival after surgery for colorectal liver metastases is based on clinical characteristics, but low accuracy makes it difficult to guide treatment for the individual patient. Rapidly evolving technologies have led to the expectation that biomarkers will be able to outperform the current clinical scoring systems and provide more effective personalised treatment. Two main topics prevail in cancer treatment, namely the role of the immune system and the prediction and prognostication by application of high-throughput methodology. The aim of this review is to examine the evidence for prognostic immunological and molecular markers studied in tumour tissue obtained at surgical resection for colorectal liver metastases.

Methods: First we analysed immunophenotypical protein markers, that are mainly studied by immunohistochemistry. Second, we review molecular markers by analysing high-throughput studies on tumour mRNA and microRNA expression.

Results: CD3, CD4, and CD8 are the most frequently studied protein markers. High intra-tumoural CD3+ T cell infiltration and low CXCR4 expression have the best association with favourable patient survival. Studies that analysed microRNA or mRNA expression data showed very little overlap in prognostic genes.

Conclusions: Patient prognostication after surgery for colorectal liver metastases by analysing the immune system remains difficult. Current data are based on diverse and heterogeneous patient populations which prohibits drawing firm conclusions.

Sub-millimeter surgical margin is acceptable in patients with good tumor biology after liver resection for colorectal liver metastases

BACKGROUND

The definition of R1 resection in colorectal cancer liver metastases (CRLM) remains debatable. This retrospective study was conducted to clarify the impact of R1 margin on patient survival after liver resection for CRLM, taking into consideration tumor biology, including RAS status and chemotherapy response.

METHODS

We retrospectively analysed the clinical and survival data of 214 CRLM patients with initially resectable liver metastases who underwent liver resection after receiving neoadjuvant chemotherapy between January 2006 and December 2016.

RESULTS

R1 resection significantly impacted patients' overall survival (OS) and disease-free survival (DFS) in the overall patient cohort (5-year OS: 53.2% for R0 vs 38.2% for R1, P = 0.001; 5-year DFS: 26.5% for R0 vs 10.5% for R1, P = 0.002). In the RAS wild-type subgroup and respond to chemotherapy (RC) subgroup, R1 reached a similar OS to those who underwent R0 resection (RAS wild-type, P = 0.223; RC, P = 0.088). For the RAS mutated subgroup and no response to chemotherapy (NRC) subgroup, OS was significantly worse underwent R1 resection (RAS mutant, P = 0.002; NRC, P = 0.022). When considering tumor biology combining RAS and chemotherapy response status, R1 resection was only acceptable in patients with both RAS wild-type and RC (5-year OS: 66.4% for R0 vs 65.2% for R1, p = 0.884), but was significantly worse in those with either RAS mutation or NRC.

CONCLUSIONS

Tumor biology plays an important role in deciding the appropriate resection margin in patients with CRLM undergoing radical surgery. R1 resection margin is only acceptable in RAS wild-type patients who respond to chemotherapy.

Angiogenic desmoplastic histopathological growth pattern as a prognostic marker of good outcome in patients with colorectal liver metastases

BACKGROUND

In patients with resectable colorectal liver metastases (CRLM), distinct histopathological growth patterns (HGPs) develop at the interface between the tumour and surrounding tissue. The desmoplastic (d) HGP is characterised by angiogenesis and a peripheral fibrotic rim, whereas non-angiogenic HGPs co-opt endogenous sinusoidal hepatic vasculature. Evidence from previous studies has suggested that patients with dHGP in their CRLM have improved prognosis as compared to patients with non-desmoplastic HGPs. However, these studies were relatively small and applied arbitrary cut-off values for the determination of the predominant HGP. We have now investigated the prognostic effect of dHGP in a large cohort of patients with CRLM resected either with or without neoadjuvant chemotherapy.

METHODS

All consecutive patients undergoing a first partial hepatectomy for CRLM between 2000 and 2015 at a tertiary referral centre were considered for inclusion. HGPs were assessed in archival H&E stained slides according to recently published international consensus guidelines. The dHGP was defined as desmoplastic growth being present in 100% of the interface between the tumour and surrounding liver.

RESULTS

In total, HGPs in CRLMs from 732 patients were assessed. In the chemo-naive patient cohort (n = 367), the dHGP was present in 19% (n = 68) and the non-dHGP was present in 81% (n = 299) of patients. This dHGP subgroup was independently associated with good overall survival (OS) (HR: 0.39, p < 0.001) and progression-free survival (PFS) (HR: 0.54, p = 0.001). All patients with any CRLM with a non-dHGP had significantly reduced OS compared to those patients with 100% dHGP, regardless of the proportion of non-dHGP (all p values ≤ 0.001). In the neoadjuvantly treated patient cohort (n = 365), more patients were found to express dHGP (n = 109, 30%) (adjusted odds ratio: 2.71, p < 0.001). On univariable analysis, dHGP was associated with better OS (HR 0.66, p = 0.009) and PFS (HR 0.67, p = 0.002). However, after correction for confounding by means of multivariable analysis no significant association of dHGP with OS (HR 0.92, p = 0.623) or PFS (HR 0.76, p = 0.065) was seen.

CONCLUSIONS

The current study demonstrates that the angiogenic dHGP in CRLM resected from chemo-naive patients acts as a strong, positive prognostic marker, unmatched by any other prognosticator. This observation warrants the evaluation of the clinical utility of HGPs in prospective clinical trials.

Evaluation of Peritumoral Fibrosis in Metastatic Colorectal Adenocarcinoma to the Liver Using Digital Image Analysis

Objectives

It is challenging to separate peritumoral fibrosis from fibrosis due to chronic liver disease in mass-directed liver biopsies. We evaluated the distance that peritumoral fibrosis extends from metastatic colorectal adenocarcinoma in liver.

Methods

Peritumoral and distant uninvolved liver trichrome stains from 25 cases were analyzed using digital image analysis. Fibrosis was quantitated at concentric intervals from each tumor and in uninvolved liver.

Results

There was a 3.9 fold (range 0.9-18.6) median increase in fibrosis in the first 0.5 mm of peritumoral liver compared to distant liver. Fibrosis levels returned to baseline at median 2.5 mm (interquartile range 1.5-5.0 mm) from tumor.

Conclusions

Fibrosis is markedly increased in peritumoral liver. Fibrosis levels returned to baseline by 5 mm from tumor in approximately 75% of cases. Pathologists should be cautious of fibrosis in mass-directed liver biopsies without at least 5 mm of liver tissue distal to the mass.

Immunohistochemical investigation of prognostic biomarkers in resected colorectal liver metastases: a systematic review and meta-analysis

Background

Many studies have investigated the prognostic role of biomarkers in colorectal liver metastases (CRLM). However, no biomarker has been established in routine clinical practice. The aim of this study was to scrutinize the current literature for biomarkers evaluated by immunohistochemistry as prognostic markers in patients with resected CRLM.

Methods

A systematic review was performed according to the PRISMA guidelines. Articles were identified in the PubMed database with selected search terms and by cross-references search. The REMARK quality criteria were applied. Markers were included if they reported the prognostic impact of immunohistochemical markers in a multivariable setting in relation to overall survival (OS). A meta-analysis was conducted when more than one original article provided survival data of a marker.

Results

In total, 26 biomarkers were identified as independent significant markers for OS in resected CRLM. These biomarkers were found to be involved in multiple oncogenic signalling pathways that control cell growth, apoptosis, angiogenesis and evasion of immune detection. Among these biomarker candidates were Ki-67, EGFR, p53, hTERT, CD34, TSP-1, KISS1, Aurora kinase A and CDX2. CD34 and TSP-1 were reported as significantly associated with survival by more than one study and where therefore pooled in a meta-analysis.

Conclusion

A number of independent prognostic biomarkers for resected CRLM were identified. However, most markers were evaluated in a retrospective setting with small patient cohorts, without external validation. Large, prospective, multicentre studies with standardised methods are needed before biomarkers can translated into the clinic.

Current status of surgical treatment of colorectal liver metastases

Liver metastasis (LM) is one of the major causes of death in patients with colorectal cancer (CRC). Approximately 60% of CRC patients develop LM during the course of their illness. About 85% of these patients have unresectable disease at the time of presentation. Surgical resection is currently the only curative treatment for patients with colorectal LM (CRLM). In recent years, with the help of modern multimodality therapy including systemic chemotherapy, radiation therapy, and surgery, the outcomes of CRLM treatment have significantly improved. This article summarizes the current status of surgical treatment of CRLM including evaluation of resectability, treatment for resectable LM, conversion therapy and liver transplantation for unresectable cases, liver resection for recurrent CRLM and elderly patients, and surgery for concomitant hepatic and extra-hepatic metastatic disease (EHMD). We believe that with the help of modern multimodality therapy, an aggressive oncosurgical approach should be implemented as it has the possibility of achieving a cure, even when EHMD is present in patients with CRLM.

Growth patterns of colorectal cancer liver metastases and their impact on prognosis: a systematic review

Background

Colorectal cancer liver metastases (CRLM) grow in distinct histological patterns that have been associated with outcome after surgical resection. We conducted a systematic review to evaluate the frequency of different CRLM growth patterns and their impact on prognosis.

Methods

We searched Embase and MEDLINE databases from inception to 1 December 2017 to identify studies that reported CRLM growth pattern histopathology, their frequencies, and/or data related to outcome.

Results

We included a total of 23 studies (2432 patients with CRLM) published between 1991 and 2017. There were variations in the terminology used to describe the growth patterns as well as in their histopathological definitions. A 'desmoplastic' pattern was most frequently considered, followed by 'pushing' and 'replacement' patterns. Data supported the presence of both intralesional and interlesional heterogeneity. There were no differences in growth pattern distribution stratified by chemotherapy. While heterogeneity of histopathology assessment precluded formal meta-analysis, the majority of articles found favourable outcomes for desmoplastic and unfavourable outcomes for replacement CRLM, independently of when the study was conducted.

Conclusions

The results suggest that CRLM growth patterns may have prognostic potential and that they may be considered for standardised routine histopathological reporting. Further understanding of the different growth patterns may provide important insights into the biological mechanisms that underlie metastatic growth in the liver.

Potential of memory T cells in bridging preoperative chemoradiation and immunotherapy in rectal cancer

The management of locally advanced rectal cancer has passed a long way of developments, where total mesorectal excision and preoperative radiotherapy are crucial to secure clinical outcome. These and other aspects of multidisciplinary strategies are in-depth summarized in the literature, while our mini-review pursues a different goal. From an ethical and medical standpoint, we witness a delayed implementation of novel therapies given the cost/time consuming process of organizing randomized trials that would bridge an already excellent local control in cT3-4 node-positive disease with long-term survival. This unfortunate separation of clinical research and medical care provides a strong motivation to repurpose known pharmaceuticals that suit for treatment intensification with a focus on distant control. In the framework of on-going phase II-III IG/IMRT-SIB trials, we came across an intriguing translational observation that the ratio of circulating (protumor) myeloid-derived suppressor cells to (antitumor) central memory CD8+ T cells is drastically increased, a possible mechanism of tumor immuno-escape and spread. This finding prompts that restoring the CD45RO memory T-cell pool could be a part of integrated adjuvant interventions. Therefore, the immunocorrective potentials of modified IL-2 and the anti-diabetic drug metformin are thoroughly discussed in the context of tumor immunobiology, mTOR pathways and revised Warburg effect.

Genetic And Morphological Evaluation (GAME) score for patients with colorectal liver metastases

BACKGROUND

This study sought to develop a clinical risk score for resectable colorectal liver metastasis (CRLM) by combining clinicopathological and clinically available biological indicators, including KRAS.

METHODS

A cohort of patients who underwent resection for CRLM at the Johns Hopkins Hospital (JHH) was analysed to identify independent predictors of overall survival (OS) that can be assessed before operation; these factors were combined into the Genetic And Morphological Evaluation (GAME) score. The score was compared with the current standard (Fong score) and validated in an external cohort of patients from the Memorial Sloan Kettering Cancer Center (MSKCC).

RESULTS

Six preoperative predictors of worse OS were identified on multivariable Cox regression analysis in the JHH cohort (502 patients). The GAME score was calculated by allocating points to each patient according to the presence of these predictive factors: KRAS-mutated tumours (1 point); carcinoembryonic antigen level 20 ng/ml or more (1 point), primary tumour lymph node metastasis (1 point); Tumour Burden Score between 3 and 8 (1 point) or 9 and over (2 points); and extrahepatic disease (2 points). The high-risk group in the JHH cohort (GAME score at least 4 points) had a 5-year OS rate of 11 per cent, compared with 73·4 per cent for those in the low-risk group (score 0-1 point). Importantly, in cohorts from both the JHH and MSKCC (747 patients), the discriminatory capacity of the GAME score was superior to that of the Fong score, as demonstrated by the C-index and the Akaike information criterion.

CONCLUSION

The GAME score is a preoperative prognostic tool that can be used to inform treatment selection.

The Immunoscore system predicts prognosis after liver metastasectomy in colorectal cancer liver metastases

BACKGROUND

The Immunoscore was initially established to evaluate the prognosis of stage I/II/III colorectal cancer patients. However, the feasibility of the Immunoscore for the prognosis of colorectal cancer liver metastases (CRCLM) has not been reported.

METHODS

Liver metastases in 249 CRCLM patients were retrospectively analyzed. The Immunoscore was assessed according to the counts and densities of CD3+ and CD8+ T cells in the central- and peritumoral areas by immunohistochemistry. The prognostic role of the Immunoscore for relapse-free survival (RFS) and overall survival (OS) was analyzed with Kaplan-Meier curves and Cox multivariate models, and confirmed via an internal validation. Receiver operating characteristic (ROC) curves were plotted to compare the prognostic values of the Immunoscore and the clinical risk score (CRS) system.

RESULTS

CRCLM patients with high Immunoscores (> 2) had significantly longer RFS [median RFS (95% confidence interval; 95% CI) 21.4 (7.8-35.1) vs. 8.7 (6.8-10.5) months, P < 0.001] and OS [median OS (95% CI): not reached vs. 28.7 (23.2-34.2) months, P < 0.001] than those with low Immunoscores (≤ 2). After stratification by CRS, the Immunoscore retained a statistically significant prognostic value for OS. The areas under the ROC curves (AUROCs) of the Immunoscore and the CRS system for RFS were 0.711 [95% CI 0.642-0.781] and 0.675[95% CI 0.601-0.749] (P = 0.492), whereas the AUROC of the Immunoscore system for OS was larger than that of the CRS system [0.759 (95% CI 0.699-0.818) vs. 0.660 (95% CI 0.592-0.727); P = 0.029].

CONCLUSIONS

The Immunoscore of liver metastases can be applied to predict the prognosis of CRCLM patients following liver resection.

Tumor-infiltrating CD45RO+ Memory T Lymphocytes Predict Favorable Clinical Outcome in Solid Tumors

The prognostic role of tumor-infiltrating CD45RO⁺ memory T lymphocytes (CD45RO⁺ T cells) in human solid tumors remains controversial. Herein, we conducted a meta-analysis including 25 published studies with 4720 patients identified from PubMed and EBSCO to assess the prognostic impact of tumor-infiltrating CD45RO⁺ T cells in human solid tumors. We found that CD45RO⁺ T cell infiltration was significantly associated with improved overall survival (OS) and disease-free survival (DFS) in all types of solid tumors. In stratified analyses, CD45RO⁺ T cell infiltration significantly improved 1-year, 3-year and 5-year OS in colorectal, gastric and esophageal cancer, but only 5-year OS in hepatocellular carcinoma. And these cells were positively associated with 1-year, 3-year and 5-year DFS in hepatocellular, colorectal and esophageal cancer. In addition, high density of intratumoral CD45RO⁺ T cells inversely correlated with TNM stage of solid tumor. In conclusion, CD45RO⁺ memory T lymphocyte infiltration leads to a favorable clinical outcome in solid tumors, implicating that it is a valuable biomarker for prognostic prediction for human solid malignances.

The Prognostic Impact of Determining Resection Margin Status for Multiple Colorectal Metastases According to the Margin of the Largest Lesion

BACKGROUND

Although the prognostic role of surgical margin status after resection of colorectal liver metastasis (CRLM) has been previously examined, controversy still surrounds the importance of surgical margin status in patients with multiple tumors.

METHODS

Patients who underwent curative-intent surgery for CRLM from 2000 to 2015 and who presented with multiple tumors were identified. Patients with R1 resection status determined by the closest resection margin of the non-largest tumor were classified as R1-Type 1; patients with R1 status determined by the resection margin of the largest tumor were defined as R1-Type 2. Data regarding surgical margin status, size of tumors, and overall survival (OS) were collected and assessed.

RESULTS

A total of 251 patients met inclusion criteria; 156 patients (62.2%) had a negative margin (R0), 50 had an R1-type 1 (19.9%), and 45 had an R1-type 2 (17.9%) margin. Median and 5-year OS in the entire cohort was 56.4 months and 48.0%, respectively. When all R1 (Type 1 + Type 2) patients were compared with R0 patients, an R1 was not associated with worse prognosis (P = 0.05). In contrast, when R1-type 2 patients were compared with R0 patients, an R1 was strongly associated with worse OS (P = 0.009). On multivariate analysis, although the prognostic impact of all R1 was not associated with OS (hazard ratio [HR] 1.56; P = 0.08), R1-Type 2 margin status independently predicted a poor outcome (HR 1.93; P = 0.03).

CONCLUSIONS

The impact of margin status varied according to the size of the tumor assessed. While R1 margin status defined according to the non-largest tumor was not associated with OS, R1 margin status relative to the largest index lesion was associated with prognosis.

Tumor Biology Rather Than Surgical Technique Dictates Prognosis in Colorectal Cancer Liver Metastases

INTRODUCTION

The interplay of tumor biology and surgical margin status after resection for colorectal liver metastasis (CRLM) remains controversial. Consequently, we sought to determine the impact of surgical margin status on overall survival (OS) stratified by KRAS mutational status.

MATERIALS AND METHODS

Four hundred eighty-five patients with known KRAS mutational status were identified. Clinicopathologic and long-term survival data were collected and assessed.

RESULTS

On pathology, most patients (n = 380; 78.3 %) had an R0 margin, while 105 (21.7 %) had an R1. Roughly two thirds of tumors were KRAS wild type (wtKRAS) (n = 307, 63.3 %), while 36.7 % (n = 178) had KRAS mutations (mutKRAS). Median and 5-year OS of the entire cohort was 65.8 months and 53.8 %, respectively. An R1 resection was associated with worse 5-year OS compared with R0 (42.4 % vs. 57.1 %; hazard ratio (HR) 1.82, 95 % CI 1.28-2.57; P = 0.001). After controlling for KRAS status, the survival benefit associated with an R0 resection persisted only among patients with wtKRAS tumors (HR 2.16, 95 % CI 1.42-3.30; P < 0.001). In contrast, surgical margin had no impact on OS among patients with mutKRAS tumors (5-year OS R0, 40.7 % vs. R1, 46.7 %; HR 1.34, 95 % CI 0.73-2.48; P = 0.348).

CONCLUSION

The impact of margin status differed by KRAS mutation status. An R0 margin only provided a survival benefit to patients with wtKRAS tumors. Tumor biology and not surgical technique determined prognosis.

Management of patients with colorectal liver metastasis in eleven questions and answers

INTRODUCTION

Colorectal liver metastasis (CRLM) is the most frequent indication for liver resection in many centers. Recent improvements in oncology, surgery, interventional radiology, pathology and anesthesiology allow curative treatment in a larger proportion of patients with CRLM. Areas covered: We illustrate the various aspects of the management of CRLM through 11 questions that summarize the topic, from the current obtained survival to future perspectives such as transplantation. The limits of a curative treatment are also presented from different angles, such as the benefits of pathology, the surgical options for extreme resections, the available chemotherapies and their efficacy, or the non-surgical ablative treatments. Expert commentary: Given the increasing therapeutic possibilities, we strengthen the importance to analyze the situation of each patient with CRLM in a dedicated multidisciplinary team, in order to offer the best individualized treatment combination.

Immune Architecture of Colorectal Lung Metastases and Implications for Patient Survival

BACKGROUND

Pulmonary metastases occur in 10-20% of patients with colorectal cancer and significantly influence long-term survival. In this study, the immunological architecture of colorectal lung in comparison to liver metastases and its impact on patient survival were examined.

METHODS

Specimens of patients with colorectal lung and liver metastases were stained for HE, CD4, CD8, CD20, CD68 and CD45RO. Besides histomorphological evaluation, immunohistochemical stainings were analyzed for the respective cell numbers separately for tumor area, infiltrative margin and distant lung or liver stroma. These findings were correlated with clinical data and patient outcome.

RESULTS

In colorectal lung (n = 69) in comparison to liver (n = 222) metastases, the immunological focus is located in the tumor region. A high CD4+ cell infiltration of this area is associated with prolonged survival of patients after resection of colorectal lung metastases [103 ± 33 (high) vs. 37 ± 6 months (low); p = 0.0246]. Patients who were treated with preoperative chemotherapy did not show differences in immune infiltrates compared to chemotherapy-naïve patients.

CONCLUSION

Colorectal lung and liver metastases showed a distinct immunological architecture. A dense cell infiltration of colorectal lung metastases by CD4+ cells was related to prolonged patient survival. Preoperative chemotherapy did not influence cellular immune infiltrates.