Quantitative Investigation of Desmoplasia as a Prognostic Indicator in Colorectal Cancer

Prognostic value of desmoplastic stroma in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinomas (iCCs) are primary tumors of the liver characterized by the presence of a desmoplastic stroma. While tumor stroma may have a protective or a pejorative value depending on the type of malignant disease, the precise role of the desmoplastic stroma in iCC remains poorly understood. The aim of the present study was to evaluate the prognostic value of stromal compartment in iCC through a multiparametric morphological analysis. Forty-nine surgically resected iCCs were included. For all cases, tumor paraffin blocks of iCCs were selected for stromal morphological characterization through quantitative and qualitative approaches using immunohistochemistry and second-harmonic generation imaging. Intratumor heterogeneity was also evaluated in regards with the different stromal features. High proportionated stromal area (PSA) (defined by stromal to tumor area ratio) was inversely correlated with vascular invasion (62.5% vs 95.7%, p = 0.006) and positively correlated with well-differentiated grade (60% vs 12.5%, p = 0.001). Patients with high PSA had a better disease-free survival (DFS) than patients with low stromal area (60% vs 10%, p = 0.077). Low activated stroma index (defined by cancer-associated fibroblasts number to stromal area ratio) was associated with a better DFS (60% vs 10%, p = 0.05). High collagen reticulation index (CRI), defined as the number of collagen fiber branches within the entire length of the collagen network, was associated with a poorer overall survival (42% vs NR, p = 0.026). Furthermore, we showed that CRI was also an homogeneous marker throughout the tumor. Based on morphological features, desmoplastic stroma seems to exert a protective effect in patients with iCC. Stromal collagen reticulation may provide additional clinically relevant information. In addition, these data support the potential value to evaluate CRI in biopsy specimen.

Prognostic value of blood-based fibrosis biomarkers in patients with metastatic colorectal cancer receiving chemotherapy and bevacizumab

A desmoplastic colorectal cancer stroma, characterized by excess turnover of the cancer-associated fibroblast derived collagens type III and VI, can lead to reduced drug-uptake and poor treatment response. We investigated the association between biomarkers of collagen type III and VI and overall survival (OS) in patients with metastatic colorectal cancer (mCRC). Serum samples were collected from 252 patients with mCRC prior to treatment with bevacizumab and chemotherapy. Serum concentrations of biomarkers reflecting formation of collagen type III (PRO-C3) and VI (PRO-C6) and degradation of collagen type VI (C6M and C6Mα3) were determined by ELISA. The biomarkers were evaluated for associations with OS, individually, combined, and after adjusting for carcinoembryonic antigen (CEA), lactate dehydrogenase (LDH) and performance status (PS). High baseline levels (> median) of each collagen biomarker were significantly associated with shorter OS (PRO-C3: HR = 2.0, 95%CI = 1.54-2.63; PRO-C6: HR = 1.6, 95%CI = 1.24-2.11; C6M: HR = 1.4, 95%CI = 1.05-1.78; C6Mα3: HR = 1.6, 95%CI = 1.16-2.07). PRO-C3 and PRO-C6 remained significant after adjustment for CEA, LDH and PS. Weak correlations were seen between the collagen biomarkers (r = 0.03-0.59) and combining all improved prognostic capacity (HR = 3.6, 95%CI = 2.30-5.76). Collagen biomarkers were predictive of shorter OS in patients with mCRC. This supports that collagen- and CAF biology is important in CRC.

Histopathological features predict metastatic potential in locally advanced colon carcinomas

Background

Metastatic dissemination can exist before a pathologically and clinically detectable manifestation. The structural heterogeneity of colon cancer (CC) in histological sections with respect to the morphology of tumor aggressiveness and composition of the tumor microenvironment raises the question of whether the microscopical tumor architecture enables a discrimination of groups with different metastatic potential. This would result in an assessment of the prognosis and provision of an ancillary tool for the therapeutic management after surgery, beside the estimation of the local tumor extent.

Methods

In order to identify predictive biomarkers for metastasis of locally advanced CC, which can easily be integrated into the pathologist’s daily routine diagnostic activity, we determined tumor budding, peritumoral inflammation, extent of desmoplasia and necrosis, density of macro- and microvascular blood vessels and functional state of lymphatics in the tumor center, invasive margin and tumor-free surrounding tissue in 86 non-metastatic, lymphogenous-metastatic and haematogenous-metastatic, subserosa-invasive CC.

Results

Features influencing nodal metastasis in the univariate analysis included high tumor budding (p = 0.004), high large vessel density in the subserosa (p = 0.043), abundant desmoplasia (p = 0.049), non-finger-like desmoplastic pattern (p = 0.051) and absent lymphocellular intratumoral inflammation (p = 0.084). In the multivariate analysis, with the exception of large vessel density, these pathomorphological features were independent risk factors for lymphogenous metastasis (p = 0.023, p = 0.017, p = 0.037, p = 0.012, respectively) with a good discrimination ability (AUC of 0.853). Features associated with distant metastasis in the univariate analysis included high tumor budding (p = 0.002), low intratumoral small vessel density (p = 0.013), absent lymphocellular intratumoral inflammation (p = 0.048) and abundant necrosis (p = 0.073). In the multivariate analysis only tumor budding was an independent predictor for haematogenous metastasis (p = 0.007) with a good discrimination ability (AUC of 0.829).

Conclusions

Thus, mainly tumor budding but also the described structural characteristics of the peritumoral tissue appears to reflect the metastatic potential of locally advanced CC and therefore should be stated in pathological reports.

In vitro models of tumor vessels and matrix: engineering approaches to investigate transport limitations and drug delivery in cancer

Tumor-stroma interactions have emerged as critical determinants of drug efficacy. However, the underlying biological and physicochemical mechanisms by which the microenvironment regulates therapeutic response remain unclear, due in part to a lack of physiologically relevant in vitro platforms to accurately interrogate tissue-level phenomena. Tissue-engineered tumor models are beginning to address this shortcoming. By allowing selective incorporation of microenvironmental complexity, these platforms afford unique access to tumor-associated signaling and transport dynamics. This review will focus on engineering approaches to study drug delivery as a function of tumor-associated changes of the vasculature and extracellular matrix (ECM). First, we review current biological understanding of these components and discuss their impact on transport processes. Then, we evaluate existing microfluidic, tissue engineering, and materials science strategies to recapitulate vascular and ECM characteristics of tumors, and finish by outlining challenges and future directions of the field that may ultimately improve anti-cancer therapies.