Background:Liver metastases present with distinct histopathological growth patterns (HGPs), including the desmoplastic, pushing and replacement HGPs and two rarer HGPs. The HGPs are defined owing to the distinct interface between the cancer cells and the adjacent normal liver parenchyma that is present in each pattern and can be scored from standard haematoxylin-and-eosin-stained (H&E) tissue sections. The current study provides consensus guidelines for scoring these HGPs.Methods:Guidelines for defining the HGPs were established by a large international team. To assess the validity of these guidelines, 12 independent observers scored a set of 159 liver metastases and interobserver variability was measured. In an independent cohort of 374 patients with colorectal liver metastases (CRCLM), the impact of HGPs on overall survival after hepatectomy was determined.Results:Good-to-excellent correlations (intraclass correlation coefficient >0.5) with the gold standard were obtained for the assessment of the replacement HGP and desmoplastic HGP. Overall survival was significantly superior in the desmoplastic HGP subgroup compared with the replacement or pushing HGP subgroup (P=0.006).Conclusions:The current guidelines allow for reproducible determination of liver metastasis HGPs. As HGPs impact overall survival after surgery for CRCLM, they may serve as a novel biomarker for individualised therapies.

The liver is host to many metastatic cancers, particularly colorectal cancer, for which the last 2 decades have seen major advances in diagnosis and treatment. The liver is a vital organ, and the extent of its involvement with metastatic disease is a major determinant of survival. Metastatic cells arriving in the liver via the bloodstream encounter the microenvironment of the hepatic sinusoid. The interactions of the tumor cells with hepatic sinusoidal and extrasinusoidal cells (endothelial, Kupffer, stellate, and inflammatory cells) determine their fate. The sinusoidal cells can have a dual role, sometimes fatal to the tumor cells but also facilitatory to their survival and growth. Adhesion molecules participate in these interactions and may affect their outcome. Bone marrowderived cells and chemokines also play a part in the early battle for survival of the metastases. Once the tumor cells have arrested and survived the initial onslaught, tumors can grow within the liver in 3 distinct patterns, reflecting differing host responses, mechanisms of vascularization, and proteolytic activity. This review aims to present current knowledge of the interactions between the host liver cells and the invading metastases that has implications for the clinical course of the disease and the response to treatment. Cancer Res; 73(7); 2031-43. Ó2013 AACR.

Successful colonization by a cancer cell of a distant metastatic site requires immune escape in the new microenvironment. TNF signaling has been implicated broadly in the suppression of immune surveillance that prevents colonization at the metastatic site and therefore must be blocked. In this study, we explored how TNF signaling influences the efficiency of liver metastasis by colon and lung carcinoma in mice that are genetically deficient for the TNF receptor TNFR2. We found a marked reduction in liver metastases that correlated with a greatly reduced accumulation at metastatic sites of CD11b

The purpose of this study was to characterise growth patterns, proteolysis, and angiogenesis in colorectal liver metastases from chemonaive patients with multiple liver metastases. Twenty-four patients were included in the study, resected for a median of 2.6 metastases. The growth pattern distribution was 25.8% desmoplastic, 33.9% pushing, and 21% replacement. In 20 patients, identical growth patterns were detected in all metastases, but in 8 of these patients, a second growth pattern was also present in one or two of the metastases. In the remaining 4 patients, no general growth pattern was observed, although none of the liver metastases included more than two growth patterns. Overall, a mixed growth pattern was demonstrated in 19.3% of the liver metastases. Compared to metastases with pushing, those with desmoplastic growth pattern had a significantly up-regulated expression of urokinase-type plasminogen activator receptor (P = 0.0008). Angiogenesis was most pronounced in metastases with a pushing growth pattern in comparison to those with desmoplastic (P = 0.0007) and replacement growth pattern (P = 0.021). Although a minor fraction of the patients harboured metastases with different growth patterns, we observed a tendency toward growth pattern uniformity in the liver metastases arising in the same patient. The result suggests that the growth pattern of liver metastases is not a random phenomenon.

Colorectal metastases in the liver grow according to three histological patterns: a pushing pattern, a replacement pattern, and a desmoplastic pattern. The objective of the current study was to explore the prognostic significance of these three growth patterns for survival. The study included 217 consecutive patients, liver resected between 2007 and 2011 due to hepatic metastases from colorectal adenocarcinoma. The growth patterns were assessed on archival hematoxylin and eosin-stained tissue sections. In 150 metastases, the density of the immune cell infiltrate at the tumor periphery was judged by a semi-quantitative method. The prevalence of the pushing-type, the desmoplastic-type, and the replacement-type was 33%, 32%, and 11%, respectively; 24% of the metastases displayed a mixed pattern. Kaplan-Meier analysis and Cox regression demonstrated a prognostic significance of the growth patterns (P ¼ 0.0006, log-rank test), as the replacement pattern appeared as an independent predictor of poor overall survival. For patients with replacement growth, the hazard of death was 2-2.5 times higher than for patients with pushing growth (P ¼ 0.004, cox regression) or mixed growth (P ¼ 0.01), and nearly four times higher than for patients with desmoplastic growth (Po0.0001). The negative prognostic effect of the replacement growth pattern was even more pronounced after adjusting for tumor size. Desmoplastic growth corresponded with small tumor size, dense lymphocytic infiltration and a more favorable prognosis. Eventually, the growth patterns may contribute to a histology-based prognostic biomarker for patients with colorectal liver metastases. Modern Pathology (2014) 27, 1641-1648; doi:10.1038/modpathol.2014.4; published online 23 May 2014Keywords: colorectal cancer; growth pattern; histopathology; liver; metastasis; prognosis; survival During the last 5-10 years, major advances have been made in both the medical and surgical treatment of liver metastases from colorectal carcinoma. The number of patients who undergo liver resection with curative intent has therefore increased significantly. However, so far, little is known on the biological, clinical, and histopathological features that determine prognosis after hepatic resection. The revised and more active treatment strategy has thus fostered a demand for new and better prognostic and predictive markers that can be used for selecting the right treatment regimen for each patient. For primary colorectal cancer, the malignant transformation from adenoma to carcinoma is by now very well described; far less described are the events that govern the progression of metastases in the liver. A greater understanding of the diverse infiltration mechanisms of the metastases, including the intricate interaction with the hepatic microenvironment, might lead to new prognostic and therapeutic prospects.Vermeulen et al 1 identified three histological growth patterns for colorectal liver metastases, suggesting biological differences: (i) a pushing growth pattern, in which the metastasis e...

Despite improved therapy of advanced colorectal cancer, the median overall survival (OS) is still low. A surgical removal has significantly improved survival, if lesions are entirely removed. The purpose of this retrospective explorative study was to evaluate the prognostic value of histological growth patterns (GP) in chemonaive and patients receiving neo-adjuvant therapy. Two-hundred-fifty-four patients who underwent liver resection of colorectal liver metastases between 2007 and 2011 were included in the study. Clinicopathological data and information on neo-adjuvant treatment were retrieved from patient and pathology records. Histological GP were evaluated and related to recurrence free and OS. Kaplan-Meier curves, log-rank test and Cox regression analysis were used. The 5-year OS was 41.8% (95% CI 33.8-49.8%). Growth pattern evaluation of the largest liver metastasis was possible in 224 cases, with the following distribution: desmoplastic 63 patients (28.1%); pushing 77 patients (34.4%); replacement 28 patients (12.5%); mixed 56 patients (25.0%). The Kaplan-Meier analyses demonstrated that patients resected for liver metastases with desmoplastic growth pattern had a longer recurrence free survival (RFS) than patients resected for non-desmoplastic liver metastases (p=0.05). When patients were stratified according to neo-adjuvant treatment in the multivariate Cox regression model, hazard ratios for RFS compared to desmoplastic were: pushing (HR=1.37, 95% CI 0.93-2.02, p=0.116), replacement (HR=2.16, 95% CI 1.29-3.62, p=0.003) and mixed (HR=1.70, 95% CI 1.12-2.59, p=0.013). This was true for chemonaive patients as well as for patients who received neo-adjuvant treatment.

Metastatic growth by colorectal cancer cells in the liver requires the ability of the cancer cells to interact with the new microenvironment. This interaction results in three histological growth patterns of liver metastases: desmoplastic, pushing, and replacement. In primary colorectal cancer several proteases, involved in the degradation of extracellular matrix components, are up-regulated. In liver metastases, their expression is growth pattern dependent. Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) is a strong prognostic marker in plasma from colorectal cancer patients, with significant higher levels in patients with metastatic disease. We therefore wanted to determine the expression pattern of TIMP-1 in primary colorectal cancers and their matching liver metastases. TIMP-1 mRNA was primarily seen in a-smoothmuscle actin (a-SMA)-positive cells. In all primary tumors and liver metastases with desmoplastic growth pattern, TIMP-1 mRNA was primarily found in a-SMA-positive myofibroblasts located at the invasive front. Some a-SMA-positive cells with TIMP-1 mRNA were located adjacent to CD34-positive endothelial cells, identifying them as pericytes. This indicates that TIMP-1 in primary tumors and liver metastases with desmoplastic growth pattern has dual functions; being an MMPinhibitor at the cancer periphery and involved in tumor-induced angiogenesis in the pericytes. In the liver metastases with pushing or replacement growth patterns, TIMP-1 was primarily expressed by activated hepatic stellate cells at the metastasis/liver parenchyma interface. These cells were located adjacent to CD34-positive endothelial cells, suggesting a function in tumor-induced angiogenesis. We therefore conclude that TIMP-1 expression is growth pattern dependent in colorectal cancer liver metastases.

Purpose: To investigate the prognostic and predictive biomarker value of type IV collagen in colorectal cancer.Experimental Design: Retrospective evaluation of two independent cohorts of patients with colorectal cancer included prospectively in 2004-2005 (training set) and 2006-2008 (validation set). Plasma samples were available from 297 (training set) and 482 (validation set) patients. Type IV collagen determinations were performed using an ELISA. From the training set, 222 tumors were available for IHC. Clinical and follow-up data were retrieved from patient files and national registries.Results: High levels of type IV collagen showed independent prognostic significance in both cohorts with hazard ratios (HRs; for a one-unit change on the log base 2 scale) of 2.25 [95% confidence intervals (CIs), 1.78-2.84; P < 0.0001] and 2.24 (95% CI, 1.75-2.86; P < 0.0001) for the training and validation set, respectively. The prognostic impact was present both in patients with metastatic and nonmetastatic disease. The predictive value of the marker was investigated in stage II and III patients. In the training set, type IV collagen was prognostic both in the subsets of patients receiving and not receiving adjuvant antineoplastic therapy. However, in the validation set, the prognostic effect of the marker vanished when looking at patients who received adjuvant antineoplatic therapy (HR 0.90; 95% CI, 0.42-1.93) but was still present in the group not receiving adjuvant chemotherapy (HR 2.88; 95% CI, 1.98-4.21).Conclusions: The results indicate clinical validity of type IV collagen as a prognostic biomarker in colorectal cancer, although the suggested predictive role of the marker should be validated.