Proliferative activity of intratumoral fibroblasts is closely correlated with lymph node and distant organ metastases of invasive ductal carcinoma of the breast

Crosstalk and plasticity driving between cancer-associated fibroblasts and tumor microenvironment: significance of breast cancer metastasis

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cell population in breast tumors. A functionally diverse population of CAFs increases the dynamic complexity of the tumor microenvironment (TME). The intertwined network of the TME facilitates the interaction between activated CAFs and breast cancer cells, which can lead to the proliferation and invasion of breast cells. Considering the special transmission function of CAFs, the aim of this review is to summarize and highlight the crosstalk between CAFs and breast cancer cells in the TME as well as the relationship between CAFs and extracellular matrix (ECM), soluble cytokines, and other stromal cells in the metastatic state. The crosstalk between cancer-associated fibroblasts and tumor microenvironment also provides a plastic therapeutic target for breast cancer metastasis. In the course of the study, the inhibitory effects of different natural compounds on targeting CAFs and the advantages of different drug combinations were summarized. CAFs are also widely used in the diagnosis and treatment of breast cancer. The cumulative research on this phenomenon supports the establishment of a targeted immune microenvironment as a possible breakthrough in the prevention of invasive metastasis of breast cancer.

Tumor-Associated Fibrosis Impairs the Response to Immunotherapy

Previously, impaired responses to immunotherapy in cancer had been attributed mainly to inherent tumor characteristics (tumor cell intrinsic factors) such as low immunogenicity, (low) mutational burden, weak host immune system, etc. However, mapping the responses of immunotherapeutic regimes in clinical trials for different types of cancer has pointed towards an obvious commonality - that tumors with a rich fibrotic stroma respond poorly or not at all. This has prompted a harder look on tumor cell extrinsic factors such as the surrounding tumor microenvironment (TME), and specifically, the fibrotic stroma as a potential enabler of immunotherapy failure. Indeed, the role of cancer-associated fibrosis in impeding efficacy of immunotherapy is now well-established. In fact, recent studies reveal a complex interconnection between fibrosis and treatment efficacy. Accordingly, in this review we provide a general overview of what a tumor associated fibrotic reaction is and how it interacts with the members of immune system that are frequently seen to be modulated in a failed immunotherapeutic regime.

Expression of Podoplanin in Mammary Cancers in Female Dogs

BACKGROUND/AIM

Mammary neoplasms are very common tumours in female dogs. Cancer-associated fibroblasts (CAFs) play an important role in the oncogenesis process. One of the useful proteins used in the diagnostics of CAFs cells is podoplanin (PDPN). The aim of our study was to assess the expression of PDPN in mammary cancer in female dogs.

MATERIALS AND METHODS

Our study cohort included 61 cancers and 21 adenomas of the mammary tumour in bitches. Expression of podoplanin, Ki-67 and HER2 was determined using the Immunohistochemical (IHC) method. PDPN expression at the mRNA level was determined using real-time PCR.

RESULTS

Expression of PDPN in CAFs was observed in 22.9% of cases of mammary cancers in bitches, with no PDPN expression in adenomas. A positive correlation was found between the expression of PDPN in CAFs and the grade of histological malignancy and expression of Ki-67.

CONCLUSION

PDPN plays a significant role during the process of carcinogenesis of mammary tumours in female dogs.

High expression of intratumoral stromal proteins is associated with chemotherapy resistance in breast cancer

We studied the changes of intratumoral stromal proteins including THBS1, TNC, FN, SPARC and α-SMA, following neoadjuvant chemotherapy. The underlying mechanisms by which THBS1 and TNC regulated resistance to docetaxel were further studied using functional studies. 100 patients with newly diagnosed breast cancer were treated with alternating sequential doxorubicin and docetaxel. Immunohistochemistry (IHC) staining for stromal proteins was performed on pre- and post-treatment core biopsies respectively. THBS1 and TNC were further validated with IHC in an independent cohort of 31 patients. A high baseline combined expression score of the 5 stromal proteins predicted independently for poor progression-free (HR_adjusted 2.22, 95% CI 1.06–4.64) and overall survival (HR_adjusted 5.94, 95% CI 2.25–15.71). After 1–2 cycles of chemotherapy, increased expression of THBS1, TNC, FN, SPARC and α-SMA was seen in patients with subsequent pathological lymph node involvement at surgery. Increased expression of THBS1 and TNC compared to baseline was also seen in intrinsically resistant tumors, but not in sensitive ones. Both THBS1 and TNC-associated chemoresistance were confirmed in an independent validation cohort. Exogenous THBS1 and TNC protected MCF-7 cells against proliferation inhibition induced by docetaxel through activating integrin β1/mTOR pathway. Thus, up-regulation of THBS1, TNC, FN, SPARC and α-SMA following neoadjuvant chemotherapy was associated with chemotherapy resistance in breast cancer patients. Functional studies showed THBS1 and TNC to mediate chemoresistance through the integrin β1/mTOR pathway, suggesting that therapies targeting integrin β1/mTOR pathway may be a promising strategy to overcome chemotherapy resistance.

MYC is expressed in the stromal and epithelial cells of primary breast carcinoma and paired nodal metastases

The MYC oncogene is directly involved in the proliferation, metabolism, progression and distant metastasis of breast cancer. Since metastatic spread to the lymph nodes is often the first indication of propensity for metastatic dissemination, the MYC status in nodal disease may represent a decision-making variable. However, the analysis of MYC expression in stromal cells, namely cancer-associated fibroblasts (CAFs), which are known to play a critical role in cancer progression, remains poorly reported. The aim of this study was to determine the expression of MYC and other markers, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), p53, Ki67, epidermal growth factor receptor (EGFR), phosphorylated AKT (p-AKT) and phospho-mammalian target of rapamycin (p-mTOR) by immunohistochemistry in representative samples from 80 patients with ductal infiltrative breast cancer and 43 paired compromised axillary lymph nodes allocated in tissue microarrays (TMAs). The epithelial and stromal components of primary tumors and respective lymph node metastases were separately analyzed. MYC expression (cytoplasmic and nuclear) was a frequent event in the epithelial and stromal components of the primary tumors. The epithelial cells in the nodal metastases exhibited a trend for decreased MYC expression compared to that in the primary tumors (P=0.08) but retained the original status of the primary tumors for all other markers. The stromal cells were uniformly negative for ER, PR, HER2, p53, Ki67 and EGFR. Comparison of the stromas of primary tumors and respective lymph node metastases revealed a reduced frequency of nuclear MYC in 15% of the cases (P=0.003), whereas p-mTOR followed a similar trend (P=0.09). Analyses of the possible correlations among markers revealed that epithelial nuclear MYC was associated with p53 (P=0.048). This is an original study demonstrating a significant proportion of MYC expression (nuclear or cytoplasmic), as well p-mTOR and p-AKT expression, in the epithelial and stromal components of either the primary tumor or the nodal metastases. CAFs expressing MYC may establish an angiogenic microenvironment supporting cancer survival and facilitating colonization at the nodal metastatic site.

Cancer-associated fibroblasts induce high mobility group box 1 and contribute to resistance to doxorubicin in breast cancer cells

Background

Cancer-associated fibroblasts and high mobility group box 1 (HMGB1) protein have been suggested to mediate cancer progression and chemotherapy resistance. The role of such fibroblasts in HMGB1 production in breast cancer is unclear. This study aimed to investigate the effects of cancer-associated fibroblasts on HMGB1 expression in breast cancer cells and its role in chemotherapeutic response.

Methods

Breast cancer-associated fibroblasts (BCFs) and non-tumor-associated fibroblasts (NTFs) were isolated from human breast cancers or adjacent normal tissues and established as primary cultures in vitro. After confirmation of the activated status of these fibroblasts, conditioned-media (CM) were collected and applied to MDA-MB-231 human triple negative breast cancer cells. The levels of intracellular and extracellular HMGB1 were measured by real-time PCR and/or Western blot. The response of BCF-CM-pre-treated cancer cells to doxorubicin (Dox) was compared with those pre-treated with NTF-CM or control cultures. The effect of an HMGB1 neutralizing antibody on Dox resistance induced by extracellular HMGB1 from non-viable Dox-treated cancer cells or recombinant HMGB1 was also investigated.

Results

Immunocytochemical analysis revealed that BCFs and NTFs were alpha-smooth muscle actin (ASMA) positive and cytokeratin 19 (CK19) negative cells: a phenotype consistent with that of activated fibroblasts. We confirmed that the CM from BCFs (but not NTFs), could significantly induce breast cancer cell migration. Intracellular HMGB1 expression was induced in BCF-CM-treated breast cancer cells and also in Dox-treated cells. Extracellular HMGB1 was strongly expressed in the CM after Dox-induced MDA-MB-231 cell death and was higher in cells pre-treated with BCF-CM than NTF-CM. Pre-treatment of breast cancer cells with BCF-CM induced a degree of resistance to Dox in accordance with the increased level of secreted HMGB1. Recombinant HMGB1 was shown to increase Dox resistance and this was associated with evidence of autophagy. Anti-HMGB1 neutralizing antibody significantly reduced the effect of extracellular HMGB1 released from dying cancer cells or of recombinant HMGB1 on Dox resistance.

Conclusions

These findings highlight the potential of stromal fibroblasts to contribute to chemoresistance in breast cancer cells in part through fibroblast-induced HMGB1 production.

Podoplanin expression in cancer-associated fibroblasts predicts aggressive behavior in melanoma

BACKGROUND

Recent studies have showed podoplanin expression in several tumors, which has been associated with lymph node metastasis and poor prognosis. Podoplanin expression in cancer-associated fibroblasts also correlates with tumor progression. However, the association of podoplanin expression with melanomas remains unclear.

METHODS

To clarify the prognostic significance of podoplanin in melanoma, podoplanin expression in tumor cells and cancer-associated fibroblasts was examined by immunohistochemistry in tissue samples collected from 55 melanoma patients.

RESULTS

Podoplanin expression in tumor cells was identified in 38 patients (69.1%) but did not show correlation with characteristics of tumor progression such as tumor thickness (p = 0.52) and sentinel lymph node (SLN) metastasis (p = 0.79). Podoplanin expression in cancer-associated fibroblasts was observed in 25 patients (45.5%), 11 of whom (44.0%) had SLN metastasis. In contrast, only 4 of 30 patients (13.3%) with podoplanin-negative cancer-associated fibroblasts exhibited SLN metastasis. Podoplanin-positive cancer-associated fibroblasts were associated with increased tumor thickness and SLN metastasis. Furthermore, patients with podoplanin-positive cancer-associated fibroblasts had poorer survival than those with podoplanin-negative cancer-associated fibroblasts (p = 0.0148).

CONCLUSION

The presence of podoplanin expression in cancer-associated fibroblasts correlates with aggressive behavior in melanoma and might therefore serve as a useful prognostic factor for patients with melanoma.

Markers of breast cancer stromal fibroblasts in the primary tumour site associated with lymph node metastasis: a systematic review including our case series

CAFs (cancer-associated fibroblasts), the most abundant cell type in breast cancer stroma, produce a plethora of chemokines, growth factors and ECM (extracellular matrix) proteins, that may contribute to dissemination and metastasis. Axillary nodes are the first metastatic site in breast cancer; however, to the present date, there is no consensus of which specific proteins, synthesized by CAFs, might be related with lymph node involvement. The purpose of this study was to perform a systematic review of CAF biomarkers associated with the presence of regional metastasis. PubMed was searched using the words: ‘breast cancer’ and ‘lymph node’ and fibroblast or stroma or microenvironment. After exclusions, eight studies evaluating biomarkers immunoexpression in CAFs and lymph node status were selected. Biomarkers evaluated in these studies may be divided in two groups, according to their ontology: extracellular matrix components [MMP13 (matrix metalloproteinase 13), TIMP2 (tissue inhibitor of metalloproteinases-2), THBS1 (thrombospondin 1), LGALS1 (lectin, galactoside-binding, soluble, 1)] and response to wounding [PDPN (podoplanin), PLAU (plasminogen activator, urokinase), PLAUR (plasminogen activator, urokinase receptor), CAV1 (caveolin 1), THBS1, LGALS1]. A positive expression of MMP13 and LGALS1 in CAFs was associated with enhanced OR (odds ratio) for regional metastasis. Contrariwise, CAV1 positive staining of fibroblasts was associated with decreased OR for nodal involvement. Expression of MMP13, PDPN and CAV1 was further tested in a new series of 65 samples of invasive ductal breast carcinomas by immunohistochemistry and no association between biomarkers expression in CAFs and nodal status was found. It was suggested that breast cancer subtypes may differentially affect CAFs behaviour. It would be interesting to evaluate the prognostic significance of these biomarkers in CAFs from different tumour types.

Intestinal GUCY2C prevents TGF-β secretion coordinating desmoplasia and hyperproliferation in colorectal cancer

Tumorigenesis is a multistep process that reflects intimate reciprocal interactions between epithelia and underlying stroma. However, tumor-initiating mechanisms coordinating transformation of both epithelial and stromal components are not defined. In humans and mice, initiation of colorectal cancer is universally associated with loss of guanylin and uroguanylin, the endogenous ligands for the tumor suppressor guanylyl cyclase C (GUCY2C), disrupting a network of homeostatic mechanisms along the crypt-surface axis. Here, we reveal that silencing GUCY2C in human colon cancer cells increases Akt-dependent TGF-β secretion, activating fibroblasts through TGF-β type I receptors and Smad3 phosphorylation. In turn, activating TGF-β signaling induces fibroblasts to secrete hepatocyte growth factor (HGF), reciprocally driving colon cancer cell proliferation through cMET-dependent signaling. Elimination of GUCY2C signaling in mice (Gucy2c(-/-)) produces intestinal desmoplasia, with increased reactive myofibroblasts, which is suppressed by anti-TGF-β antibodies or genetic silencing of Akt. Thus, GUCY2C coordinates intestinal epithelial-mesenchymal homeostasis through reciprocal paracrine circuits mediated by TGF-β and HGF. In that context, GUCY2C signaling constitutes a direct link between the initiation of colorectal cancer and the induction of its associated desmoplastic stromal niche. The recent regulatory approval of oral GUCY2C ligands to treat chronic gastrointestinal disorders underscores the potential therapeutic opportunity for oral GUCY2C hormone replacement to prevent remodeling of the microenvironment essential for colorectal tumorigenesis.

Notch and TGF-β/Smad3 pathways are involved in the interaction between cancer cells and cancer-associated fibroblasts in papillary thyroid carcinoma

Accumulating evidence suggests that cancer-associated stromal fibroblasts (CAFs) contribute to tumor growth by actively communicating with cancer cells. Our aim was to identify the signaling pathways that are involved in tumor-stromal cell interactions in human papillary thyroid carcinoma (PTC). Immunohistochemical analyses were performed with 127 archived formalin-fixed and paraffin-embedded thyroid tissue samples that included 70 cases of PTC, 35 cases of nodular goiter (NG), and 22 cases of normal thyroid tissues. The results showed that the expression levels of Notch1, transforming growth factor β (TGF-β1), and p-Smad3 in PTC cells and α-smooth muscle actin (α-SMA) in the stroma of PTC were all significantly higher than in NG and normal thyroid tissues. Further analysis showed that in PTC, higher expression levels of Notch1 and TGF-β1 were closely related with lymph node metastasis (P < 0.05), whereas for α-SMA and p-Smad3, the percent expression increased significantly with advanced tumor stages (P < 0.05). Correlation analysis revealed that TGF-β1 expression increased with increased Notch1 and p-Smad3 levels in PTC cells (P < 0.05). Moreover, a significant correlation was found between higher TGF-β1 expression in PTC cells and increased α-SMA levels in the fibroblasts surrounding the cancer cells (P < 0.05). We identified TGF-β1 as an important factor from PTC cells that act in a paracrine manner to influence the activation of stromal fibroblasts. These data suggest that the activation of Notch and TGF-β/Smad3 pathways in cancer cells influence tumor growth. Moreover, cancer cell-derived-TGF-β ligands also affect stromal cells in a paracrine fashion and enhance tumor growth.

Tumour-microenvironment interactions: role of tumour stroma and proteins produced by cancer-associated fibroblasts in chemotherapy response

BACKGROUND

Cytotoxic chemotherapy improves survival for some, but not all, cancer patients. Non-responders may experience unnecessary toxicity and cancer progression, thus creating an urgent need for biomarkers that can predict the response to chemotherapy. So far, the search for such biomarkers has primarily been focused on the cancer cells and less on their surrounding stroma. This stroma is known to act as a key regulator of tumour progression and, in addition, has been associated with drug delivery and drug efficacy. Fibroblasts represent the major cell type in cancer-associated stroma and they secrete extracellular matrix proteins as well as growth factors. This Medline-based literature review summarises the results from studies on epithelial cancers and aimed at investigating relationships between the quantity and quality of the intra-tumoral stroma, the cancer-associated fibroblasts, the proteins they produce and the concomitant response to chemotherapy. Biomarkers were selected for review that are known to affect cancer-related characteristics and patient prognosis.

RESULTS

The current literature supports the hypothesis that biomarkers derived from the tumour stroma may be useful to predict response to chemotherapy. This notion appears to be related to the overall quantity and cellularity of the intra-tumoural stroma and the predominant constituents of the extracellular matrix.

CONCLUSION

Increasing evidence is emerging showing that tumour-stroma interactions may not only affect tumour progression and patient prognosis, but also the response to chemotherapy. The tumour stroma-derived biomarkers that appear to be most appropriate to determine the patient's response to chemotherapy vary by tumour origin and the availability of pre-treatment tissue. For patients scheduled for adjuvant chemotherapy, the most promising biomarker appears to be the PLAU: SERPINE complex, whereas for patients scheduled for neo-adjuvant chemotherapy the tumour stroma quantity appears to be most relevant.

Tumor-stromal interactions in breast tumor progression--significance of histological heterogeneity of tumor-stromal fibroblasts

INTRODUCTION

Existing pathological diagnostic protocols for breast cancer do not fully reflect the biological characteristics of tumor stromata. To improve the pathological diagnosis of breast cancer, a new pathological diagnostic method capable of assessing the degree of breast cancer malignancy based on the histological features of the tumor stroma is needed.

AREAS COVERED

The presence of a fibrotic focus (FF), which consists of fibroblasts or collagen fibers, and the presence of atypical tumor-stromal fibroblasts are significantly associated with nodal metastasis or distant-organ metastasis in patients with invasive ductal carcinoma (IDC) of the breast. FF is the only factor that is significantly associated with an increase in tumor angiogenesis. The importance of FF and atypical tumor-stromal fibroblasts clearly indicates that the malignant potential of IDC does not depend only on the biological characteristics of the tumor cell, but also on those of the tumor stroma.

EXPERT OPINION

The biological characteristics of fibroblasts forming an FF or atypical tumor-stromal fibroblasts probably differ from those of fibroblasts located outside an FF or ordinary tumor-stromal fibroblasts. Thus, similar to tumor cells, the heterogeneity of tumor-stromal fibroblasts probably influences the outcome of patients with IDC of the breast.

Podoplanin expressing cancer associated fibroblasts are associated with unfavourable prognosis in adenocarcinoma of the esophagus

Overexpression of the mucin-type sialoglycoprotein podoplanin in cancer associated fibroblasts (CAFs) was recently shown to be associated with tumor progression, metastasis and poor prognosis in lung and breast cancer. Here we investigate the role of podoplanin expressing CAFs in esophagal adenocarcinoma (AC), its precursor lesions and metastases. Podoplanin expression was investigated immunohistochemically in 200 formalin-fixed, paraffin embedded specimens of invasive esophagal ACs, their corresponding metastases and 35 precursor lesions. Podoplanin expressing CAFs (CAF+) were observed in 22 % of patients with invasive AC, but not in precursor lesions. CAF+ correlated with tumor stage (p = 0.004), lymphovascular tumor invasion (p = 0.018) and lymph node metastasis (p = 0.0016). Patients with CAF+ had a significant shorter disease free and overall survival (p < 0.05, Cox regression). Podoplanin expressing CAFs were only rarely observed in lymph node and distant metastases, as well as in local recurrences of ACs. Podoplanin expression in AC tumor cells was seen in only four cases. In around 20 % of patients with esophagal AC, podoplanin expressing CAFs are evident, defining a high risk subgroup. In these patients, podoplanin expressing CAFs might represent new therapeutical targets.

Fibrotic focus and hypoxia in male breast cancer

Fibrotic focus is a scar-like lesion near the center of a carcinoma and has been associated with high-grade, lymph node metastases and poor survival in female breast cancers. Hypoxia is suggested to be the crucial link between fibrotic focus and aggressive tumor phenotype and is also itself a poor prognostic marker. We here set out to study fibrotic focus and hypoxia in male breast cancer for the first time. In a group of 134 male breast cancer patients, the presence and size of a fibrotic focus and the expression of three hypoxia-related immunohistochemical stainings, hypoxia-inducible factor-1α, carbonic anhydrase IX and Glut-1 were studied in correlation with clinicopathological features and prognosis. Fibrotic focus was seen in 25% of the male breast cancer cases and was correlated with hypoxia-inducible factor-1α overexpression (P=0.023), high grade (P=0.005), high mitotic activity (P=0.005) and lymph node metastases (P=0.037). Hypoxia-inducible factor-1α-positive tumors were more often high grade (P=0.003) and HER2 amplified (P=0.005). Glut-1 expression was also more common in grade 3 tumors (P=0.038), but no association between carbonic anhydrase IX and any clinicopathological feature was found. Fibrotic focus >8 mm and hypoxia-inducible factor-1α overexpression were correlated with decreased patients' outcome (P=0.035 and 0.008, respectively). Hypoxia-inducible factor-1α overexpression was an independent and the most powerful predictor of survival in multivariate analysis (P=0.029; hazard ratio 2.5). In conclusion, the presence of a fibrotic focus is associated with hypoxia-inducible factor-1α overexpression, and both are associated with aggressive tumor phenotype and poor survival in male breast cancer. These markers seem to have similar clinical importance as previously reported in female breast cancer.

Podoplanin-expressing cancer-associated fibroblasts are associated with poor prognosis in invasive breast cancer

While cancer research has been focused on tumor cells for many years, evidence is growing that the tumor stroma and in particular cancer-associated fibroblasts (CAFs) in particular play essential roles in the progression of human malignant disease. In human lung cancer, CAFs expressing the transmembrane protein podoplanin were shown to have significant influence on the patients' prognosis. In this study, we investigated the presence and prognostic role of podoplanin-expressing CAFs in a large series of patients with invasive breast cancer. Podoplanin expression was evaluated immunohistochemically in 367 breast cancers. Tumors with ≥10% distinct podoplanin staining were considered as positive (CAF+). Cytoplasmic podoplanin expression of tumor cells was considered as positive when ≥5% of tumor cells showed a distinct podoplanin expression. In normal breast tissue, no podoplanin-expressing fibrocytes were found. Thirty-three patients (9%) with breast cancer showed podoplanin expression in CAFs. In 28 patients (8%), a podoplanin expression in tumor cells was observed. A strong negative correlation of CAF+ with estrogen receptor status (p<0.001), and a significant association with higher histological grading (p<0.001) was seen. In multivariable analysis, CAFs+ was an independent prognostic factor for disease free (1.78 Hazard ratio; p=0.026) and overall survival (2.304 Hazard ratio; p=0.002) in patients with breast cancer. Podoplanin-expressing CAFs contribute to the prognosis of invasive breast cancer, indicating a highly aggressive subgroup. CAFs may present a highly selective target for anti-cancer therapies in patients with invasive breast cancer.

Upregulation of cancer-associated myofibroblasts by TGF-β from scirrhous gastric carcinoma cells

BACKGROUND

Myofibroblasts in the cancer microenvironment have recently been implicated in tumour growth and metastasis of gastric cancer. However, the mechanisms responsible for the regulation of myofibroblasts in cancer-associated fibroblasts (CAFs) remain unclear. This study was performed to clarify the mechanisms for regulation of myofibroblasts in gastric cancer microenvironment.

METHODS

Two CAFs (CaF-29 and CaF-33) from the tumoural gastric wall and a normal fibroblast (NF-29) from the nontumoural gastric wall, 4 human gastric cancer cell lines from scirrhous gastric cancer (OCUM-2MD3 and OCUM-12), and non-scirrhous gastric cancer (MKN-45 and MKN-74) were used. Immunofluorescence microscopy by triple-immunofluorescence labelling (α-SMA, vimentin, and DAPI) was performed to determine the presence of α-SMA-positive myofibroblasts. Real-time RT-PCR was performed to examine α-SMA mRNA expression.

RESULTS

Immunofluorescence microscopy showed that the frequency of myofibroblasts in CaF-29 was greater than that in NF-29. The number of myofibroblasts in gastric fibroblasts gradually decreased with serial passages. Transforming growth factor-β (TGF-β) significantly increased the α-SMA expression level of CAFs. Conditioned medium from OCUM-2MD3 or OCUM-12 cells upregulated the α-SMA expression level of CAFs, but that from MKN-45 or MKN-74 cells did not. The α-SMA upregulation effect of conditioned medium from OCUM-2MD3 or OCUM-12 cells was significantly decreased by an anti-TGF-β antibody or Smad2 siRNA.

CONCLUSION

Transforming growth factor-β from scirrhous gastric carcinoma cells upregulates the number of myofibroblasts in CAFs.

Role of stromal myofibroblasts in invasive breast cancer: stromal expression of alpha-smooth muscle actin correlates with worse clinical outcome

BACKGROUND

Recently, the desmoplastic reaction has been implicated as having an important function in epithelial solid tumor biology. There have been no reports showing the relativity of invasive breast cancer and the desmoplastic reaction by a quantitative analysis of the myofibroblasts that were an important player in the desmoplastic reaction. The purpose of this study was to immunohistochemically investigate the correlation between the desmoplastic reaction and the clinicopathology of invasive breast cancer.

METHODS

The study included 60 patients with a known prognosis of invasive breast cancer. We quantified the expression of α-SMA as a marker of myofibroblasts in the invasive breast cancer. After staining samples for α-SMA, their expression was extracted and quantified as a relative percentage by computer-assisted image analysis.

RESULTS

There was relatively wide variation in the expression of α-SMA with the percentage of the area from 0.68 to 28.15% (mean 8.48 ± 5.40%). The metastasis group showed significantly higher α-SMA expression compared with the no metastasis group (p < 0.001). When the patients were divided into two groups according to their α-SMA expression using a cutoff point at the mean value of 8.48%, the high α-SMA group had a significantly poorer overall survival rate (p < 0.001). Multivariate analysis demonstrated that α-SMA and lymph node metastasis were identified as independent predictive factors of metastasis.

CONCLUSION

Myofibroblasts represent an important prognostic factor for invasive growth that is translated into a poor clinical prognosis for patients with invasive breast cancer.

p53 expression in tumor-stromal fibroblasts forming and not forming fibrotic foci in invasive ductal carcinoma of the breast

The purpose of this study was to determine whether p53 protein expression in tumor-stromal fibroblasts forming fibrotic foci is a significant outcome predictor, similar to p53 protein expression in tumor-stromal fibroblasts not forming fibrotic foci, and whether the combined assessment of p53 expression in tumor-stromal fibroblasts forming and not forming fibrotic foci served as an important outcome predictor among 1039 patients with invasive ductal carcinoma of the breast. We analyzed the outcome predictive power of the Allred score risk classification for p53 in tumor-stromal fibroblasts forming and not forming fibrotic foci using multivariate analyses with well-known clinicopathological factors. The Allred score risk classifications for p53 in tumor-stromal fibroblasts forming and not forming fibrotic foci were superior to the Allred scores for p53 in tumor-stromal fibroblasts not forming fibrotic foci alone for accurately predicting the tumor-related death of patients with invasive ductal carcinoma when examined using multivariate analyses. The Allred score risk classification for p53 in tumor-stromal fibroblasts forming and not forming fibrotic foci significantly increased the hazard rates for tumor recurrence and tumor-related death independent of the UICC pTNM stage in the multivariate analyses. These results indicated that the Allred score risk classification based on the combined assessment of p53 expression in tumor-stromal fibroblasts forming and not forming fibrotic foci is a very useful outcome predictor among patients with invasive ductal carcinoma.

p53 expression in tumor-stromal fibroblasts is closely associated with the nodal metastasis and outcome of patients with invasive ductal carcinoma who received neoadjuvant therapy

The purpose of this study was to determine whether p53 immunoreactivity in tumor-stromal fibroblasts assessed by the Allred scoring system in biopsy specimens obtained before neoadjuvant therapy and assessed in surgical specimens obtained after neoadjuvant therapy is significantly associated with nodal metastasis by invasive ductal carcinoma and with the outcome of 318 patients with invasive ductal carcinoma who received neoadjuvant therapy, according to UICC pathologic TNM stage, in multivariate analyses with well-known clinicopathologic factors. The Allred scores for p53 in tumor-stromal fibroblasts in the surgical specimens were significantly associated with the presence of nodal metastasis. The Allred scores for p53 in the tumor-stromal fibroblasts of biopsy and surgical specimens were a very important outcome predictive factor for patients who received neoadjuvant therapy, independent of UICC pathologic TNM status, but the outcome predictive power of the Allred scores for p53 in tumor-stromal fibroblasts assessed in the surgical specimens was superior to that of the Allred scores for p53 in tumor-stromal fibroblasts in the biopsy specimens. The results indicated a close association between p53 protein expression in tumor-stromal fibroblasts, especially in surgical specimens, and both the presence of nodal metastasis and the outcome of invasive ductal carcinoma patients who received neoadjuvant therapy.

p53 expression in tumor stromal fibroblasts is associated with the outcome of patients with invasive ductal carcinoma of the breast

The purpose of this study was to determine whether p53 protein expression in tumor stromal fibroblasts assessed immunohistochemically by the Allred score system is significantly associated with nodal metastasis by invasive ductal carcinoma (IDC), and significantly associated with the outcome of 1042 IDC patients according to adjuvant therapy status, UICC pTNM stage, and triple-negative IDC status, in multivariate analyses with well-known clinicopathological factors. The Allred scores for p53 expression in tumor stromal fibroblasts were significantly associated with the number of nodal metastases, and Allred scores of 4-8 for p53 in tumor stromal fibroblasts significantly increased the hazard rate for distant organ metastasis or for tumor death in the triple-negative IDC patients, and the UICC pTNM stage I, II, and III patients. The results indicated that p53 protein expression in tumor stromal fibroblasts is closely associated with the number of nodal metastases and the outcome of IDC patients.

Tumor histology in lymph vessels and lymph nodes for the accurate prediction of outcome among breast cancer patients treated with neoadjuvant chemotherapy

The present study investigated fibrotic foci (FFs), the grading system for lymph vessel tumor emboli (LVTEs), and the histological characteristics of nodal metastatic tumors that were significantly associated with the outcomes of 115 patients with invasive ductal carcinoma (IDC) who had received neoadjuvant chemotherapy. We compared the outcome predictive power of FFs, the grading system for LVTEs, and the histological characteristics of metastatic tumors in lymph nodes with the well-known clinicopathological characteristics of tumor recurrence and tumor-related death in multivariate analyses. The presence of FFs, as assessed by a biopsy performed before neoadjuvant chemotherapy, significantly increased the hazard rates (HRs) for tumor-related death in all the cases and in cases with nodal metastasis. The grading system for LVTEs, which was assessed using surgical specimens obtained after neoadjuvant chemotherapy, was significantly associated with increasing hazard rates (HRs) for tumor recurrence and tumor-related death in all the cases and in cases with nodal metastasis. Moderate to severe stroma in nodal metastatic tumors and five or more mitotic figures in nodal metastatic tumors were significantly associated with elevated HRs for tumor recurrence and tumor-related death among all the cases. These results indicated that FFs, the grading system for LVTEs, and the histological characteristics of tumor cells in lymph nodes play important roles in predicting the tumor progression of IDCs of the breast in patients treated with neoadjuvant chemotherapy.

Bioselection of a gain of function mutation that enhances adenovirus 5 release and improves its antitumoral potency

Genetic bioselection of a mutagenized Ad5wt stock in human tumor xenografts led us to isolate AdT1, a mutant displaying a large-plaque phenotype in vitro and an enhanced systemic antitumor activity in vivo. AdT1 phenotype correlates with an increased progeny release without affecting total viral yield in different human tumors and cancer-associated fibroblasts. An approach combining hybrid Ad5/AdT1 recombinants and sequencing identified a truncating insertion in the endoplasmic reticulum retention domain of the E3/19K protein (445A mutation) which relocates the protein to the plasma membrane and is responsible for AdT1's enhanced release. E3/19K-445A phenotype does not correlate with the protein's ability to interact with MHC-I or induce apoptosis. Intracellular calcium measurement revealed that the 445A mutation induces extracellular Ca(2+) influx, deregulating intracellular Ca(2+) homeostasis and inducing membrane permeabilization, a viroporin-like function. E3/19K-445A mutants also display enhanced antitumoral activity when injected both intratumorally and systemically in different models in vivo. Our results indicate that the inclusion of mutation 445A in tumor-selective adenoviruses would be a very powerful tool to enhance their antitumor efficacy.

Mesenchymal stem cells as vectors for lung disease

Stem cells divide asymmetrically, leading to self-renewal and the production of a daughter cell committed to differentiation. This property has engendered excitement as to the use of these cells for treatments. The majority of the work with stem cells has used the relatively accessible and well-characterized adult bone marrow stem cell compartment. Initially the focus of this research was on the potential for these stem cells to repair damaged organs by differentiating into epithelial cells to replace the injured areas. More recently it has become clear that engraftment of these stem cells as epithelial tissue is a rare event with perhaps limited clinical significance. Despite this, stem cells appear to have the ability to home to and be specifically recruited to areas of inflammation and injured tissues often characterized by excessive extracellular matrix deposition. As a consequence they are intimately involved in regions of physiological and pathological repair. Coupled with this, autologous hematopoietic stem cells, or the relatively immunoprivileged mesenchymal stem cells, can be expanded and engineered ex vivo and reintroduced without immunomodulation. The prospect of using such cells clinically as a cellular therapy holds much promise for many conditions and organ pathologies. Here we address the evidence for the incorporation of bone marrow stem cells into areas of stroma formation as a prelude to possible future treatment options for common lung diseases.

Podoplanin expression by cancer associated fibroblasts predicts poor prognosis of lung adenocarcinoma

Recent studies have reported increased podoplanin expression by cancer cells and stromal cells, but little is known about its expression and biological significance in adenocarcinoma of the lung. We examined podoplanin expression by both cancer cells and stromal cells in 177 consecutive lung adenocarcinoma cases and analyzed relations between podoplanin expression and both clinicopathological factors and outcome. Podoplanin expression was observed on the apical membrane of the cancer cells in only 9 of the 177 (5.1%) cases. By contrast, cancer-associated fibroblasts (CAFs) were found to express podoplanin in 54 cases (30.5%). Podoplanin (+) CAFs were found only in invasive adenocarcinoma and none were found in noninvasive adenocarcinoma. Conventional prognostic factors were significantly correlated with podoplanin expression by CAFs. The univariate analyses and log-rank test showed that podoplanin expression was significantly associated with shorter survival time (p < 0.001 and p < 0.001, respectively). We divided the cases into 3 groups according grade based on the proportion of CAFs expressing podoplanin [a grade 0 group (n = 123), a grade 1 group (n = 36) and a grade 2 group (n = 18)]. The result showed that conventional prognostic factors were significantly correlated with the grade of podoplanin expression by CAFs. Furthermore, the grade 2 group tended to have a shorter survival time than the grade 1 group (p = 0.092). The results of this study highlight the importance of podoplanin expression by CAFs and provide new insights into the biology of the cancer microenvironment in adenocarcinoma of the lung.

A novel role of thrombospondin-1 in cervical carcinogenesis: inhibit stroma reaction by inhibiting activated fibroblasts from invading cancer

Thrombospondin (TSP)-1, a potent angiogenesis inhibitor, has been shown to exert different biological functions on various cell types. Here, we investigate the role of TSP-1 in tumor-stroma reaction, which is mainly characterized by fibroblast activation to create a permissive microenvironment for tumor progression. Immunohistochemistry examinations in the human surgical specimens have shown that a downregulation of TSP-1 during the progression of cervical carcinogenesis was accompanied by an emergence in the upregulation of stroma markers, alpha-smooth muscle actin (alpha-SMA) and desmin. Transfection of SiHa cervical cancer cells with a plasmid expressing the TSP-1 protein exhibited antiangiogenic activity in vitro and resulted in reduced tumor growth in severe combined immunodeficiency (SCID) mice, which was accompanied by a decrease in tumor vascularization and lower expressions of alpha-SMA and desmin than those in the vector controls. Transfection with TSP-1 and purified TSP-1 added to NIH3T3 cells did not alter the protein levels of alpha-SMA and desmin but significantly inhibited matrix metalloprotease-2 activity. Transforming growth factor-beta (TGF-beta), a major factor in the activation of fibroblasts, increased alpha-SMA and desmin expression and the ability of cell migration and invasion in NIH3T3 cells. The increased migration ability and the invasive ability into tumor cluster of TGF-beta-treated NIH3T3 cells were dose dependently inhibited by TSP-1. In contrast, ectopic TSP-1 expression in SiHa cells has little effect on the invasive ability of the NIH3T3 cells. Together, our findings demonstrate a novel role of TSP-1 to inhibit tumor-stroma reaction that could be attributed to the blockage of activated fibroblasts from invading cancer cells.

Predictors of axillary lymph node metastasis in breast cancer: A systematic review

AIMS

To review the established and emerging techniques in axillary lymph node prediction and explore their potential impact on clinical practice. To reliably identify patients in whom axillary lymph node surgery, including SLNB, can be safely omitted.

METHODS

Searches of PubMed were made using the search terms "axilla" (or "axillary"), "lymph", "node" and "predictor" (or "prediction"). Articles from abstracts and reports from meetings were included only when they related directly to previously published work.

FINDINGS

There are numerous studies in which the predictive utility of biomarkers as determinants of axillary lymph node status have been investigated. Few of these have specifically addressed the attributes of the primary tumour which could offer much potential for the prediction of tumour metastasis to the axillary lymph nodes.

CONCLUSIONS

Currently, no single marker is sufficiently accurate to obviate the need for formal axillary staging using SLNB or axillary clearance.

Allometric Scaling Law Questions the Traditional Mechanical Model for Axillary Lymph Node Involvement in Breast Cancer

Purpose

To find a quantitative relationship between tumor size and frequency of axillary lymph node involvement.

Patients and Methods

The frequency of axillary node involvement versus primary tumor volume was analyzed in 10 selected series of patients incorporating a total of 57,244 women with resectable breast cancer. The average number of events per unit volume resulting in tumor spread to axillary lymph nodes before tumor surgical removal Θ(V)/V, was estimated under simple probabilistic assumptions.

Results

The allometric scaling law Θ(V)/V = 0.0586V−0.7457 was estimated on the data, fitting the proportion of lymph node involvement on tumor volume V (in microliters). The estimate 0.7457 (95% CI, 0.7200 to 0.7713) suggests that the true scaling exponent, under the assumed model, may be the fractional value, which characterizes scaling relationships for a wide variety of biologic variables at both the whole organism level and organ level.

Conclusion

Results suggest that the phenomenon should be related to some internal structural trait of the tumor. The vascular network seems to be the best candidate. This result does not support a mere mechanical model of lymphatic tumor spread. A more complex biology-based model of lymphohematogenous spread is suggested, in which the axillary nodes draining the lymph from the primary tumor may become activated by factors produced by both tumor cells and tumor stroma, thus favoring cell-selective homing of otherwise circulating tumor cells. The success of fractal features related to the internal architecture brings additional support to the consideration of primary breast cancer as an organ-like structure.

Basement membrane matrix modifies cytokine interactions between lung cancer cells and fibroblasts

OBJECTIVE

Proliferation of fibroblasts (desmoplastic reaction) in the lung adenocarcinomas is an important phenomenon that correlates with metastases and poor prognosis. Because basement membranes are often involved in the desmoplastic areas and many cytokines have binding capacity to basement membrane molecules, we hypothesized that basement membrane modify the paracrine effects between cancer cells and fibroblasts via the fibrogenic cytokines and this hypothesis was experimentally investigated.

METHODS

The effects of conditioned media derived from ten lung carcinoma cell lines and normal airway epithelial cells on DNA synthesis of fetal lung fibroblasts were determined. We focused on fibroblast growth factor 2 (FGF-2) as the candidate paracrine cytokines and examined their diffusion through an experimental basement membrane matrix model, Matrigel.

RESULTS

All the conditioned media promoted DNA synthesis of fetal lung fibroblasts. Detection by ELISA methods and the neutralizing antibodies suggested that FGF-2 was one of the responsible factors for the growth promotion. Diffusion of FGF-2 across the polycarbonate membrane was suppressed by coating with Matrigel. When FGF-2-secreting A549 cells were covered with Matrigel, FGF-2 was stored in Matrigel and its diffusion into the culture media was significantly reduced. Binding of FGF-2 to Matrigel was completely blocked by a basic protein, protamine sulfate. In the presence of protamine sulfate in Matrigel overlaid on A549 cells, diffusion of FGF-2 increased 7-fold as much as that without overlaid Matrigel.

CONCLUSION

These results suggest that the basement membrane acts as a barrier to the diffusion and a reservoir of cytokines secreted by cancer cells, and that the subsequent degradation of the basement membrane by cancer cells could release the stored cytokines and promote growth of fibroblasts.

Multivariate prognostic evaluation of the mitotic activity index and fibrotic focus in node-negative invasive breast cancers

We validated with univariate and multivariate (Cox) analysis, the prognostic value of the mitotic activity index (MAI), the fibrotic focus (FF) and other prognosticators in 448 patients with lymph node-negative (LN-) invasive breast cancer <55 years without adjuvant systemic treatment (72.5 months median follow-up, range 4-119). Of these patients, 24.8% developed distant and 1.6% loco-regional recurrence. FF showed excellent inter-observer reproducibility (kappa = 0.93). Strong prognosticators were MAI, grade, nuclear atypia, FF and the St. Gallen criterion (SG). The subgroup with excellent survival selected by SG was only 16% of all patients, implying over-treatment of more than 70% of all LN- patients when using SG as adjuvant therapy selection criterion. If MAI <10, 13% showed distant metastases, contrasting with 41% if MAI > or = 10. FF was prognostic in the ductal and mixed ductal cancers, but not in the lobular and other subtype cancers. Patients with invasive (mixed) ductal cancers with FF absent, FF < 1/3 or FF > 1/3 of the tumour area, had distant metastasis rates of 17%, 35% and 48%; in MAI < 10 and FF absent, FF < 1/3 or FF > 1/3, metastasis rates were 11%, 13% and 42% and if MAI > or = 10, metastasis rates were 31%, 48% and 50%, respectively. In the 12 patients with MAI < 10 and a large FF > 1/3, event-free survival was similar to patients with MAI > or = 10. With multiple regression MAI < 10 versus > or = 10 is the strongest prognosticator (also stronger than the SG). The FF may be important as it has additional prognostic value to the MAI in the small subgroup of invasive ductal or mixed-ductal breast cancer patients with combined MAI < 10 and an FF > 1/3 of the tumour area.

Invasive ductal carcinoma with fibrotic focus: mammographic and sonographic findings with histopathologic correlation

OBJECTIVE

We sought to define the imaging findings of invasive ductal carcinoma with fibrotic focus and its associated histopathologic correlation.

CONCLUSION

Radiologists should be aware of the imaging characteristics of this newly described entity because of the significant prognostic implications and perhaps to prompt the pathologist to assess for the presence of a fibrotic focus at excision.

Histological characteristics of tumor cells and stromal cells in vessels and lymph nodes are important prognostic parameters of extrahepatic bile duct carcinoma: a prospective study

Extrahepatic bile duct carcinomas (EHBDCs) consist of primary tumors, tumors in vessels, and tumors in lymph nodes. The purpose of this study was to prospectively investigate whether the histological characteristics of tumor cells and tumor stromal cells in vessels and lymph nodes were significantly associated with the outcomes of 60 EHBDC patients as compared with the histological characteristics of tumor cells and tumor stromal cells in primary tumors. Multivariate analyses, using the Cox proportional hazard regression model, showed that in EHBDCs without nodal metastasis, blood vessel tumor emboli with an angiomatous stroma significantly increased the hazard ratios (HRs) of tumor recurrence and death ( P < .05). In EHBDCs with nodal metastasis, the presence of tumor necrosis in the nodal tumors significantly increased the HRs of tumor recurrence and initial distant organ metastasis ( P < .05). In EHBDCs located in the distal to middle portion of the extrahepatic bile duct, blood vessel tumor emboli with an angiomatous stroma significantly increased the HRs of tumor recurrence, initial distant organ metastasis, and death ( P < .05). Severe nuclear atypia of the tumor cells in lymph vessels significantly increased the HRs of tumor recurrence and initial distant organ metastasis ( P < .05). In EHBDCs located in the hilar portion of the extrahepatic bile duct, the presence of nodal tumors with more than 4 mitotic figures significantly increased the HRs of tumor recurrence and initial distant organ metastasis ( P < .05). Several histological characteristics of tumor cells and tumor stromal cells in vessels and lymph nodes have significant effects on tumor progression of EHBDCs.

A new in vitro model for analyzing the biological behavior of well-differentiated squamous cell carcinoma

A suitable model analyzing the behavior of well-differentiated squamous cell carcinoma has not yet been established. We tried to establish such a system using a reconstructed oral mucosa, in which T3M-1 squamous cell carcinoma cells were cultured on 3T3 fibroblast-containing collagen gel. Fibroblasts promoted the stratification and keratinization of T3M-1 cells. During growth, the Ki-67 index of T3M-1 cells with fibroblasts was higher than that of T3M-1 cells alone. Fibroblasts increased the expression of involucrin, a differentiating marker of keratinocytes, in T3M-1 cells. They also promoted the invasion of T3M-1 cells into the gel. When T3M-1 cells alone were cultured in a fibroblast-conditioned (FC) medium, the fibroblast-induced phenomena mentioned above were almost replicated. In addition, epidermal growth factqr (EGF) promoted T3M-1 cells growth, but not the invasion. cDNA microarray analysis showed that FC medium increased the expression of EGF receptor and several other mRNAs of T3M-1 cells. The data suggest that T3M-1 cells, under cancer-stromal fibroblast interaction, undergo invasive growth with their well-differentiated squamous phenotype, and that this interaction may be mediated partly by soluble molecules (e.g., EGF) in an autocrine or paracrine pathway. Our system will probably provide a useful model for analyzing the biological behavior of well-differentiated squamous cell carcinoma.

Human breast tumors override the antiangiogenic effect of stromal thrombospondin-1in vivo

The antiangiogenic extracellular matrix protein thrombospondin-1 (TSP-1) inhibits tumor growth and metastasis in animals. However, the clinical relevance of such findings are equivocal as increased stromal TSP-1 expression has been associated with either good or poor prognosis. In an effort to obtain a more integrated understanding of the role of TSP-1 in breast cancer, we first used a breast tumorigenesis model in which tumor-associated stromal fibroblasts were engineered to produce high levels of TSP-1. We demonstrate here that stromal TSP-1 delayed human MDA-MB-231/B02 breast tumor growth. However, this delay in MDA-MB-231/B02 tumor growth upon exposure to TSP-1 was associated with an increased vascular endothelial growth factor (VEGF) expression in tumor cells themselves, leading to a tumor growth rate comparable to that of tumors whose fibroblasts did not overproduce TSP-1. Clinical evidence also suggested that primary breast carcinomas have adapted to escape the effects of stromal TSP-1. TSP-1 was found to be expressed in the stroma of human breast carcinomas where, although its level correlated with decreased vascularization, it was unexpectedly associated with a reduction of relapse-free survival. In metastatic axillary lymph nodes, tumor cells expressed high levels of VEGF and TSP-1 expression were no longer associated with a decreased vascularization. Overall, these results suggest that a resistance may develop early in human breast cancers as a result of high in situ exposure to stromal TSP-1, leading to disease progression.

In vivo andin vitro characterization of human fibroblasts recruited selectively into human cancer stroma

Fibroblasts, which are a major component of cancer-induced stroma, can have a significant impact on the progression of adjacent malignant epithelia. To characterize fibroblasts recruited into cancer-induced stroma, we examined the recruitment efficiency of 9 human fibroblast cell lines into experimental tumors generated in immunodeficient mice. Green fluorescence protein (GFP)-labeled fibroblast cell lines and human pancreatic cancer cell line Capan-1 were injected i.p. at different sites; the GFP-labeled cells within xenografts were then analyzed. KM104GFP (bone marrow) and VA-13GFP (lung) were selectively recruited into cancer stroma more efficiently than the other cell lines. KM104GFP cells did not affect tumor volume; however, VA-13GFP cells increased tumor volume by about 2-fold. After 5 cyclic in vivo passages of KM104GFP in Capan-1, we selected a subpopulation with an 8.4-fold higher recruitment efficiency (KM104GFP-5G) compared to parental KM104GFP. KM104GFP-5G also exhibited higher chemotaxis and chemoinvasion activity compared to KM104GFP in response to cancer-released chemoattractant(s). Oligonucleotide microarray analysis identified 8 genes with >3-fold upregulation and 6 genes with >3-fold downregulation in KM104GFP-5G. Immunohistochemistry confirmed that fibroblasts recruited into pancreatic cancer stroma strongly expressed carbonic anhydrase IX and keratin-8, whose transcripts were upregulated in KM104GFP-5G by oligonucleotide microarray analysis, whereas their expression in fibroblasts within noncancerous pancreatic stroma were under the detection level. Our results indicate that fibroblast recruitment is not selective with respect to organ origin and that particular fibroblast subpopulations with specific phenotypic characteristics could be recruited efficiently into cancer-induced stroma.

Clinicopathological significance of stromal myofibroblasts in invasive ductal carcinoma of the breast

The purpose of this study was to investigate the distribution of CD34-positive fibroblasts and alpha-smooth muscle actin (alpha-SMA)-reactive myofibroblasts in the stroma of benign and malignant breast lesions and, secondly, to determine whether the presence of stromal myofibroblasts is associated with some of the clinicopathological characteristics of patients with invasive ductal carcinoma. The presence of stromal CD34-positive fibroblasts and myofibroblasts was investigated (as defined immunohistochemically) in 8 normal breast tissue samples, 58 invasive ductal carcinomas, 9 ductal carcinomas in situ and 16 specimens with benign lesions of the breast (fibroadenomas, ductal hyperplasias). We further studied the correlations between the presence of stromal myofibroblasts with 7 clinicopathological parameters in 58 invasive ductal carcinomas. The results indicated that the stroma of normal breast tissues contained CD34-positive fibroblasts. All benign breast lesions exhibited stromal CD34-positive fibroblasts. In contrast, the stroma of ductal carcinomas showed a complete loss of CD34-positive fibroblasts. alpha-SMA expression in stromal fibroblasts (myofibroblasts) was not detected in normal tissue samples or benign lesions except in 1 case of fibroadenoma, whereas positive myofibroblasts were found in 44.4% of ductal carcinomas in situ and 56.9% of invasive breast carcinomas. Comparison of clinicopathological parameters between invasive ductal carcinomas with and without stromal myofibroblasts revealed significant differences in lymph node metastasis, high histological grade and high microvessel density. These results suggest that CD34 loss and the presence of myofibroblasts favor the diagnosis of breast carcinoma. In invasive ductal carcinoma, the presence of stromal myofibroblasts correlated significantly with pathological parameters associated with a poor prognosis.

Histological characteristics of tumor in vessels and lymph nodes are significant predictors of progression of invasive ductal carcinoma of the breast: a prospective study

Invasive ductal carcinomas (IDCs) of the breast are composed of primary invasive tumors as well as tumor cells in blood vessels and lymph nodes. The purpose of this study was to determine whether the histological characteristics of tumor in the vessels and nodes are significantly associated with outcome. In a series of 393 patients, multivariate analyses showed that in IDCs without nodal metastasis and with fibrotic focus dimension, lymph vessel tumor emboli with >6 apoptotic figures and those invading >3 mm from the tumor margin had significantly higher hazard rates (HRs) for recurrence (P<0.05). In IDCs with 1 to 3 nodal metastases, >2 apoptotic figures in tumor emboli in blood vessels and >5 invaded lymph vessels were associated with significantly higher HRs for tumor recurrence and death (P<0.005). In IDCs with 4 or more nodal metastases, nodal tumors with >5 mitotic figures and >5 nodes with extranodal extension were associated with significantly higher HRs for tumor recurrence or death (P<0.05). We conclude that several histological characteristics of tumors in vessels and nodes have significant implications for the progression of IDCs.

Bone-marrow-derived myofibroblasts contribute to the cancer-induced stromal reaction

To confirm whether human cancer-induced stromal cells are derived from bone marrow, bone marrow (BM) cells obtained from beta-galactosidase transgenic and recombination activating gene 1 (RAG-1) deficient double-mutant mice (H-2b) were transplanted into sublethally irradiated severe combined immunodeficient (SCID) mice (H-2d). The human pancreatic cancer cell line Capan-1 was subcutaneously xenotransplanted into SCID recipients and stromal formation was analyzed on day 14 and on day 28. Immunohistochemical and immunofluorescence studies revealed that BM-derived endothelial cells (X-gal/CD31 or H-2b/CD31 double-positive cells) and myofibroblasts (X-gal/alpha-smooth muscle actin or H-2b/alpha-smooth muscle actin double-positive cells) were present within and around the cancer nests. On day 14, the frequencies of BM-derived endothelial cells and BM-derived myofibroblasts were 25.3+/-4.4% and 12.7+/-9.6%, respectively. On day 28, the frequency of BM-derived endothelial cells was 26.7+/-9.7%, which was similar to the value on day 14. However, the frequency of BM-derived myofibroblasts was significantly higher (39.8+/-17.1%) on day 28 than on day 14 (P<0.05). The topoisomerase IIalpha-positive ratio was 2.2+/-1.2% for the H-2b-positive myofibroblasts, as opposed to only 0.3+/-0.4% for the H-2b-negative myofibroblasts, significant proliferative activity was observed in the BM-derived myofibroblasts (P<0.05). Our results indicate that BM-derived myofibroblasts become a major component of cancer-induced stromal cells in the later stage of tumor development.

The Presence of a Fibrotic Focus in Invasive Breast Carcinoma Correlates with the Expression of Carbonic Anhydrase IX and is a Marker of Hypoxia and Poor Prognosis

The value of the fibrotic focus (FF) as a marker of intra-tumoral hypoxia in invasive breast carcinoma was assessed by studying its relationship with the expression of the hypoxia-induced carbonic anhydrase IX (CA IX), angiogenesis indices and prognosis. CA IX expression was immunohistochemically detected in 2 independent study groups, totaling 184 patients, and correlated with tumor characteristics, angiogenesis related parameters and patient outcome by univariate analysis. CA IX immunostaining scores in carcinoma cells and in tumoral fibroblasts were significantly higher in expansively growing tumors (p = 0.0001 and p < 10(-4), respectively), containing an FF (p = 0.0004 and p < 10(-4)) and showing high histological grade (p = 0.016 and p = 0.0006). Microvessel density, quantified by Chalkley counting, was correlated with CA IX expression both in the carcinoma cells and in the fibroblasts (p = 0.0076 and p = 0.0025) and with the presence and relative size of an FF (p = 0.006). The fraction of proliferating endothelial cells was positively correlated with CA IX scores in the fibroblasts (r = 0.4, p = 0.02) and with the presence of an FF (p = 0.02). CA IX scores in the fibroblasts--and to a lesser extent in the carcinoma cells--were associated with a higher relapse rate (p = 0.006) and a worse overall survival (p = 0.003). The highest CA IX immunostaining scores were found in the fibroblasts of large FF occupying more than one-third of the tumor. A large FF was associated with worse overall survival in a consecutive patient group (p = 0.01) and with shorter disease-free (p = 0.02) and overall survival (p = 0.0005) in T1-2N0 breast cancer patients. The strong association of CA IX expression with the presence of an FF shows that the latter is a marker of intra-tumoral hypoxia. FF is useful as a surrogate marker of hypoxia-driven ongoing angiogenesis and is associated with a higher relapse rate and a worse overall survival.

Tumor cells in lymph vessels and lymph nodes closely associated with nodal metastasis by invasive ductal carcinoma of the breast

No studies have ever precisely investigated the mechanism of nodal metastasis based on the histological characteristics of tumor cells in lymph vessels and lymph nodes. The purpose of this study was to investigate whether the histological characteristics of tumor cells in lymph vessels and lymph nodes of 393 patients with invasive ductal carcinoma (IDC) were significantly associated with increased nodal metastasis compared with well known histological characteristics of their primary-invasive tumor cells. Multivariate analyses showed that having a single nodal metastasis was closely dependent on primary-invasive tumor size or distance of lymph vessel tumor emboli from the margin of the primary-invasive tumor (P < 0.05) and that having 2 or more nodal metastases was significantly associated with the histological characteristics of the nodal metastatic tumors independently of the size of the primary-invasive tumor, and the number of nodes with extra-nodal invasion (ENI) significantly increased the relative risk (RR) of 4 or more nodal metastases in IDCs 20 to 50 mm in size, number of lymph vessels invaded, severe fibrosis of the stroma of extra-nodal invasive tumors, and distance of ENI from the node significantly increased the RR of 10 or more nodal metastases in the multivariate analysis (P < 0.05). The results of this study strongly suggest that the histological characteristics of tumor cells in lymph nodes and lymph vessels play an important role in nodal metastasis in IDCs of the breast.

Proliferative activities of tumor stromal cells play important roles in tumor thickness and progression of T3 ulcerative-type colorectal cancer

The central depressed area thickness (tumor thickness) of colorectal cancers is an important prognostic parameter for colorectal cancer patients. We examined whether the proliferative activities of tumor and stromal components play important roles in the increase of tumor thickness and the progression of colorectal cancers. Colorectal cancers were classified into thin and thick groups according to tumor thickness. The proliferative activities of fibroblasts and endothelial cells were immunohistochemically evaluated in 157 T3 ulcerative-type colorectal cancers by CD31/MIB-1 (anti-Ki-67 antigen) double staining. The MIB-1 labeling index was estimated as the percentage of fibroblasts with positive nuclei. The CD31-positive microvessels lined by MIB-1-positive endothelial cells were assessed. The proliferative microvessel index was defined as the percentage of proliferative microvessels relative to all microvessels. The fibroblast MIB-1 labeling index was the only parameter significantly associated with tumor thickness ( P=0.049). High fibroblast MIB-1 labeling indices showed significant correlation with tumor recurrence in the thin group ( P=0.020). High proliferative microvessel index was a significant parameter of tumor recurrence in the thick group ( P=0.003) in multivariate analyses. This study strongly suggests that proliferative activities of stromal components are useful parameters of tumor biology and of prognosis for T3 ulcerative-type colorectal cancer patients.

Advanced pancreatic ductal cancer: fibrotic focus and beta-catenin expression correlate with outcome

INTRODUCTION

Many investigators have examined prognostic factors for advanced pancreatic ductal cancer, but it is still difficult to accurately predict the outcome of the disease.

AIM

To examine correlation between histopathologic factors and outcome of advanced ductal carcinoma of the pancreas.

METHODOLOGY

The subjects were 23 patients who underwent resection of pancreatic ductal cancer classified as stage III according to pTNM classification. Fibrotic focus (which is evidence of intratumoral fibroblast proliferation), tumor size and differentiation, invasion to the portal vein, and immunohistologic expression of E-cadherin and alpha-, beta- andbgr;- and gamma-catenins were evaluated. Correlation between histologic and immunohistologic data and correlation between these data and liver metastasis-free survival and overall survival were assessed by means of the Kaplan-Meier method, the log-rank test, and the Cox proportional hazards regression model (for multivariate analysis).

RESULTS

The presence of fibrotic focus correlated with reduced membranous beta-catenin expression. The presence of fibrotic focus, reduced membranous beta-catenin expression, and reduced cytoplasmic alpha-catenin expression were significantly associated with shorter liver metastasis-free survival. The presence of fibrotic focus also significantly correlated with shorter survival and was the only factor significantly associated with survival in multivariate analysis.

CONCLUSION

The presence of fibrotic focus and reduced beta-catenin expression closely correlated with poor survival of patients with advanced ductal carcinoma of the pancreas.

Cell proliferation and chromosomal changes in human ameloblastoma

Cell proliferation and chromosomal imbalances, important parameters in relation to tumor progression, were studied in ameloblastoma (n=20), a benign odontogenic tumor of locally recurrent nature. Immunocytochemical staining with MIB-1 antibody and comparative genomic hybridization (CGH) were performed on formalin-fixed paraffin-embedded ameloblastomas. The mean follow-up time was 12.4 years. An MIB-1-index was formed by counting 5000 tumor-cell nuclei in 10-15 randomly chosen high-power fields and calculating percentages of positively stained cells. CGH involved hybridization of FITC-dUTP-labeled tumor DNA with Texas-red-labeled normal DNA. Images were digitally analyzed. The MIB-1-index (range 0-2.51) was low for all tumors. No statistically significant correlation between MIB-1 index and tendency to recurrence was found. Chromosomal aberrations were detected in 2 of 17 cases. The results suggest that formation of an MIB-1 index is not helpful in assessing future clinical behavior of an ameloblastoma and that chromosomal imbalances are uncommon.

Prognostic significance of fibrotic focus in invasive ductal carcinoma of the breast: a prospective observational study

We have already reported invasive ductal carcinomas (IDCs) with fibrotic focus (FF) to be associated with significantly poorer survival than IDCs without FF. The purpose of this study was to prospectively investigate the effect of the presence of FF on the outcomes of 439 patients with IDCs to confirm the prognostic significance of FF, by the multivariate analysis, employing the Cox proportional hazard regression model, as compared with well-known clinicopathological parameters. We also precisely evaluated the prognostic significance of FF from the viewpoint of FF characteristics. The present study demonstrated that the presence of FF is a very useful parameter predicting tumor recurrence (TR), as well as initial distant organ metastasis (IDOM), in lymph node-negative IDCs (P =.024 and P =.026) and in IDCs positive for either or both estrogen receptor (ER) or progesterone receptor (PR) (P =.007 and P =.015), respectively. In addition, FF of >8 mm in diameter was found to be an independent prognostic parameter for TR and IDOM in lymph node-negative patients and patients with IDC positive for either or both ER or PR (P =.005 and P =.018). We conclude that the presence of FF is a very important histologic prognostic parameter for patients with IDCs of the breast.

Highly proliferative fibroblasts forming fibrotic focus govern metastasis of invasive ductal carcinoma of the breast

We have already reported that invasive ductal carcinomas (IDCs) with fibrotic focus (FF) have more aggressive characteristics than those without FF. FF is composed of a mixture of fibroblasts and various amounts of collagen fibers, suggesting that highly proliferative fibroblasts forming FF increase the malignant potential of IDCs with FF. The purpose of this study was to examine whether there is a difference of proliferative activity of fibroblasts forming and not forming FF, which plays an important role in the tumor progression of IDCS: Two hundred three consecutive cases of IDC of the breast surgically treated at the National Cancer Center Hospital East formed the basis for this study. The proliferative activity of the fibroblasts forming the FF was immunohistochemically evaluated by using mouse MIB-1 monoclonal antibody against Ki-67 antigen. The MIB-1 labeling index (LI) is the percentage of fibroblasts forming FF that have positively stained nuclei, and 300 fibroblasts were counted in each FF. The significance of the proliferative activity of fibroblasts forming FF with regard to lymph node metastasis (LNM) or distant-organ metastasis (DOM) was compared with well-known prognostic parameters. Multivariate analysis demonstrated that high MIB-1 LI of fibroblasts forming FF significantly increased the relative risk of LNM and the hazard rate of DOM (P < .001 and P = .009). The present study indicated that the metastatic ability of IDCs with FF is highly dependent on the proliferative activity of the fibroblasts forming FF.

Highly proliferative intratumoral fibroblasts and a high proliferative microvessel index are significant predictors of tumor metastasis in T3 ulcerative-type colorectal cancer

Fibroblast and endothelial cell mitotic figures are seen in some areas of colorectal cancers, and the purpose of this study was to investigate whether the proliferative activity of fibroblasts and endothelial cells plays an important role in tumor progression of T3 ulcerative-type colorectal cancer. The tumor area of 157 colorectal cancers was divided into marginal elevated area and central depressed area (CDA), and at half the depth of the depression the CDA was in turn divided into CDA upper area (CDAU) and CDA lower area (CDAL). The proliferative activity of the tumor cells, fibroblasts, and endothelial cells was assessed immunohistochemically by double CD31/MIB-1 (anti--Ki-67 antigen) staining. The proliferative microvessel index was estimated as the percentage of microvessels lined by MIB-1-positive endothelial cells relative to the total microvessel count. Proliferative activities of tumor cells showed significant associations with those of fibroblasts and the proliferative microvessel indices in all of the corresponding areas. Proliferative activities of fibroblasts also showed significant associations with proliferative microvessel indices in all of the corresponding areas. Colorectal cancers with nodal metastasis showed significantly higher proliferative activities of fibroblasts in the CDAU than those without nodal metastasis (P <.001). The high proliferative activities of fibroblasts and proliferative microvessel indices in the CDAU showed significant associations with short distant organ metastasis-free periods in colorectal cancers without nodal metastasis (P <.001 and P =.010, respectively) and those with nodal metastasis (P =.024 and P =.036, respectively). Multivariate analysis showed that the highly proliferative fibroblasts in the CDAU significantly increased hazard rates of distant organ metastasis of colorectal cancer patients with nodal metastasis (P =.018). Proliferative activities of fibroblasts and endothelial cells in the CDAU are useful parameters for predicting tumor metastasis in patients with T3 ulcerative-type colorectal cancer. HUM PATHOL 32:401-409.

Early distant relapse in "node-negative" breast cancer patients is not predicted by occult axillary lymph node metastases, but by the features of the primary tumour

Early distant relapse occurs in a minority of node-negative breast cancer patients. Whether this poor prognosis can be predicted by the features of the primary tumour, or by the presence of occult metastases in the "negative" lymph nodes (LNs), remains a matter of debate. One hundred and four T(1-2)N(0)M(0) breast carcinoma patients were divided into two groups: group 1 (44%) showing early distant relapse with a median disease-free survival of 25 months, and group 2 (56%) showing no evidence of disease after a median follow-up of 91.5 months. All patients had received locoregional treatment only. All tumours were evaluated for medial/lateral location, histological type, size, grade, mitotic activity, fibrotic focus, necrosis, angiogenesis, growth pattern, and lymphatic vessel permeation. The haematoxylin and eosin-stained slides of all axillary LNs were revised and two additional levels were cut from each paraffin block for cytokeratin immunohistochemistry. In 24 patients (23%), occult metastases were found. These consisted of single cells or small clusters (SCs) in the marginal sinus in 17 patients (16%) and of larger colonies of cells in seven patients (7%). All detected metastases were smaller than 2 mm in diameter (micrometastases). There was no significant correlation between the presence of occult LN metastases (SCs or colonies) and the prognostically important features of the primary tumour. Early metastatic disease was significantly correlated with larger tumour size (p=0.02), higher histological grade (p=0.0008), mitotic activity (p<0.0001), presence of necrosis (p=0.0004), presence of fibrotic foci (p=0.0005), angiogenesis (p=0.0009), and lymphatic vessel permeation (p=0.018). Multiple logistic regression analysis showed that histological grade and the presence of a fibrotic focus were the only independent prognostic factors and that the presence of occult LN metastases was inversely correlated with early distant relapse. Prospective prognostic studies of occult LN metastases should consider the features of the primary tumour in a multivariate analysis.

New prognostic histological parameter of invasive ductal carcinoma of the breast: clinicopathological significance of fibrotic focus

Immunohistochemistry, DNA ploidy analysis and molecular genetics have made it possible to predict the outcome of breast cancer more precisely than routine histological examination alone. However, in routine practice, it is difficult to incorporate these methodologies in all cases. If certain histological parameters can accurately predict the outcome of patients with breast cancer, they would be more practical for routine use. We showed that the presence of fibrotic focus (FF) in invasive ductal carcinoma (IDC) is closely associated with c-erbB-2 or p53 protein expression, high proliferative activity, and high angiogenesis of the tumors. Furthermore, multivariate analyses with well-known prognostic parameters for IDC demonstrated that the presence of FF is the most useful independent parameter to predict IDC patient outcome. In addition, our data suggested that the interaction between tumor cells and stromal fibroblasts may play an important role in the formation of FF in IDC based on growth factor and growth factor receptor protein expression in the tumor cells and fibroblasts forming FF. Based on the results of our clinicopathological studies, we propose a new prognostic classification scheme for the prediction of IDC patient outcome, which consists of FF, nuclear atypia, and fat invasion. This classification has superior predicting power to existing prognostic classifications.