Disorganised stroma determined on pre-treatment breast cancer biopsies is associated with poor response to neoadjuvant chemotherapy: Results from the NEOZOTAC trial

Intraoperative Imaging Techniques in Oncology

Imaging-based procedures have become well integrated into the diagnosis and management of oncological patients and play a significant role in reducing morbidity and mortality rates. Here we describe the established and upcoming surgical oncological imaging techniques and their impact on cancer management.

Tumour-stroma ratio (TSR) in breast cancer: comparison of scoring core biopsies versus resection specimens

PURPOSE

Tumour-stroma ratio (TSR) is an important prognostic and predictive factor in several tumour types. The aim of this study is to determine whether TSR evaluated in breast cancer core biopsies is representative of the whole tumour.

METHOD

Different TSR scoring methods, their reproducibility, and the association of TSR with clinicopathological characteristics were investigated in 178 breast carcinoma core biopsies and corresponding resection specimens. TSR was assessed by two trained scientists on the most representative H&E-stained digitised slides. Patients were treated primarily with surgery between 2010 and 2021 at Semmelweis University, Budapest.

RESULTS

Ninety-one percent of the tumours were hormone receptor (HR)-positive (luminal-like). Interobserver agreement was highest using 100 × magnification (κ_core = 0.906, κ_{resection specimen} = 0.882). The agreement between TSR of core biopsies and resection specimens of the same patients was moderate (κ = 0.514). Differences between the two types of samples were most frequent in cases with TSR scores close to the 50% cut-off point. TSR was strongly correlated with age at diagnosis, pT category, histological type, histological grade, and surrogate molecular subtype. A tendency was identified for more recurrences among stroma-high (SH) tumours (p = 0.07). Significant correlation was detected between the TSR and tumour recurrence in grade 1 HR-positive breast cancer cases (p = 0.03).

CONCLUSIONS

TSR is easy to determine and reproducible on both core biopsies and in resection specimens and is associated with several clinicopathological characteristics of breast cancer. TSR scored on core biopsies is moderately representative for the whole tumour.

Investigating the role of core needle biopsy in evaluating tumor-stroma ratio (TSR) of invasive breast cancer: a retrospective study

PURPOSE

Tumor-stroma ratio (TSR) of invasive breast carcinoma has gained attention in recent years due to its prognostic significance. Previous studies showed TSR is a potential biomarker for indicating the tumor response to neoadjuvant chemotherapy. However, it is not clear how well TSR evaluation in biopsy specimens might reflect the TSR in resection specimens. We conducted a study to investigate whether biopsy evaluation of TSR can be an alternative method.

METHOD

We collected cases with invasive breast carcinoma of no special type (IBC-NST) from University of Yamanashi hospital between 2011 and 2017 whose biopsy and resection specimens both had a pathologically diagnosis of IBC-NST (n = 146). We conceptualized a method for evaluating TSR in biopsy specimens within a preliminary cohort (n = 50). Within the studied cohort (n = 96), biopsy-based TSR (b-TSR) and resection-based TSR (r-TSR) were scored by two pathologists. We then evaluated our method's validity and performance by measuring interobserver variability between the two pathologists, Spearman's correlation between b-TSR and r-TSR, and the receiver operating characteristics (ROC) analysis for defining stroma-rich and stroma-poor tumors.

RESULTS

Intra-class coefficient between the two pathologists was 0.59. The correlation coefficients between b-TSR and r-TSR in the two pathologists were 0.45 and 0.37. The ROC areas under the curve were 0.7 and 0.67. By considering an r-TSR of < 50% as stroma-rich, the sensitivity and specificity of detecting stroma-rich tumors were 64.1% and 66.7%, respectively, when b-TSR was < 40%.

CONCLUSION

Our current b-TSR evaluation method can provide information about r-TSR and facilitate pre-treatment therapy follow-up.

Predicting neoadjuvant chemotherapy benefit using deep learning from stromal histology in breast cancer

Neoadjuvant chemotherapy (NAC) is a standard treatment option for locally advanced breast cancer. However, not all patients benefit from NAC; some even obtain worse outcomes after therapy. Hence, predictors of treatment benefit are crucial for guiding clinical decision-making. Here, we investigated the predictive potential of breast cancer stromal histology via a deep learning (DL)-based approach and proposed the tumor-associated stroma score (TS-score) for predicting pathological complete response (pCR) to NAC with a multicenter dataset. The TS-score was demonstrated to be an independent predictor of pCR, and it not only outperformed the baseline variables and stromal tumor-infiltrating lymphocytes (sTILs) but also significantly improved the prediction performance of the baseline variable-based model. Furthermore, we discovered that unlike lymphocytes, collagen and fibroblasts in the stroma were likely associated with a poor response to NAC. The TS-score has the potential to better stratify breast cancer patients in NAC settings.

Breast cancer microenvironment and obesity: challenges for therapy

Women with obesity who develop breast cancer have a worsened prognosis with diminished survival rates and increased rates of metastasis. Obesity is also associated with decreased breast cancer response to endocrine and chemotherapeutic treatments. Studies utilizing multiple in vivo models of obesity as well as human breast tumors have enhanced our understanding of how obesity alters the breast tumor microenvironment. Changes in the complement and function of adipocytes, adipose-derived stromal cells, immune cells, and endothelial cells and remodeling of the extracellular matrix all contribute to the rapid growth of breast tumors in the context of obesity. Interactions of these cells enhance secretion of cytokines and adipokines as well as local levels of estrogen within the breast tumor microenvironment that promote resistance to multiple therapies. In this review, we will discuss our current understanding of the impact of obesity on the breast tumor microenvironment, how obesity-induced changes in cellular interactions promote resistance to breast cancer treatments, and areas for development of treatment interventions for breast cancer patients with obesity.

Standardization of the tumor-stroma ratio scoring method for breast cancer research

Purpose

The tumor-stroma ratio (TSR) has repeatedly proven to be correlated with patient outcomes in breast cancer using large retrospective cohorts. However, studies validating the TSR often show variability in methodology, thereby hampering comparisons and uniform outcomes.

Method

This paper provides a detailed description of a simple and uniform TSR scoring method using Hematoxylin and Eosin (H&E)-stained core biopsies and resection tissue, specifically focused on breast cancer. Possible histological challenges that can be encountered during scoring including suggestions to overcome them are reported. Moreover, the procedure for TSR estimation in lymph nodes, scoring on digital images and the automatic assessment of the TSR using artificial intelligence are described.

Conclusion

Digitized scoring of tumor biopsies and resection material offers interesting future perspectives to determine patient prognosis and response to therapy. The fact that the TSR method is relatively easy, quick, and cheap, offers great potential for its implementation in routine diagnostics, but this requires high quality validation studies.

Second-Harmonic Generation Imaging Reveals Changes in Breast Tumor Collagen Induced by Neoadjuvant Chemotherapy

Breast cancer is the most common invasive cancer in women, with most deaths attributed to metastases. Neoadjuvant chemotherapy (NACT) may be prescribed prior to surgical removal of the tumor for subsets of breast cancer patients but can have diverse undesired and off-target effects, including the increased appearance of the 'tumor microenvironment of metastasis', image-based multicellular signatures that are prognostic of breast tumor metastasis. To assess whether NACT can induce changes in two other image-based prognostic/predictive signatures derived from tumor collagen, we quantified second-harmonic generation (SHG) directionality and fiber alignment in formalin-fixed, paraffin-embedded sections of core needle biopsies and primary tumor excisions from 22 human epidermal growth factor receptor 2-overexpressing (HER2+) and 22 triple-negative breast cancers. In both subtypes, we found that SHG directionality (i.e., the forward-to-backward scattering ratio, or F/B) is increased by NACT in the bulk of the tumor, but not the adjacent tumor-stroma interface. Overall collagen fiber alignment is increased by NACT in triple-negative but not HER2+ breast tumors. These results suggest that NACT impacts the collagenous extracellular matrix in a complex and subtype-specific manner, with some prognostic features being unchanged while others are altered in a manner suggestive of a more metastatic phenotype.

Dissecting the single-cell transcriptome network in patients with esophageal squamous cell carcinoma receiving operative paclitaxel plus platinum chemotherapy

Esophageal squamous cell carcinoma (ESCC) accounts for 90% of all cases of esophageal cancers worldwide. Although neoadjuvant chemotherapy (NACT-ESCC) improves the survival of ESCC patients, the five-year survival rate of these patients is dismal. The tumor microenvironment (TME) and tumor heterogeneity decrease the efficacy of ESCC therapy. In our study, 113,581 cells obtained from five ESCC patients who underwent surgery alone (SA-ESCC) and five patients who underwent preoperative paclitaxel plus platinum chemotherapy (NACT-ESCC), were used for scRNA-seq analysis to explore molecular and cellular reprogramming patterns. The results showed samples from NACT-ESCC patients exhibited the characteristics of malignant cells and TME unlike samples from SA-ESCC patients. Cancer cells from NACT-ESCC samples were mainly at the ‘intermediate transient stage’. Stromal cell dynamics showed molecular and functional shifts that formed the immune-activation microenvironment. APOE, APOC1, and SPP1 were highly expressed in tumor-associated macrophages resulting in anti-inflammatory macrophage phenotypes. Levels of CD8+ T cells between SA-ESCC and NACT-ESCC tissues were significantly different. Immune checkpoints analysis revealed that LAG3 is a potential immunotherapeutic target for both NACT-ESCC and SA-ESCC patients. Cell–cell interactions analysis showed the complex cell-cell communication networks in the TME. In summary, our findings elucidate on the molecular and cellular reprogramming of NACT-ESCC and ESCC patients. These findings provide information on the potential diagnostic and therapeutic targets for ESCC patients.

Tumor-stroma ratio is associated with Miller-Payne score and pathological response to neoadjuvant chemotherapy in HER2-negative early breast cancer

The tumor-stroma ratio (TSR) has proven to be a strong prognostic factor in breast cancer, demonstrating better survival for patients with stroma-low tumors. Since the role of the TSR as a predictive marker for neoadjuvant chemotherapy outcome is yet unknown, this association was evaluated for HER2-negative breast cancer in the prospective DIRECT and NEOZOTAC trials. The TSR was assessed on 375 hematoxylin and eosin-stained sections of pre-treatment biopsies. Associations between the TSR and chemotherapy response according to the Miller-Payne (MP) grading system, and between the TSR and pathological response were examined using Pearson's chi-square, Cochran-Armitage test for trend and regression analyses. A stroma-low tumor prior to neoadjuvant chemotherapy was significantly associated with a higher MP score (P = .005). This relationship remained significant in the estrogen receptor (ER)-negative subgroup (P = .047). The univariable odds ratio (OR) of a stroma-low tumor on pathological complete response (pCR) was 2.46 (95% CI 1.34-4.51, P = .004), which attenuated to 1.90 (95% CI 0.85-4.25, P = .119) after adjustment for relevant prognostic factors. Subgroup analyses revealed an OR of 5.91 in univariable analyses for ER-negativity (95% CI 1.19-29.48, P = .030) and 1.48 for ER-positivity (95% CI 0.73-3.01, P = .281). In conclusion, a low amount of stroma on pre-treatment biopsies is associated with a higher MP score and pCR rate. Therefore, the TSR is a promising biomarker in predicting neoadjuvant treatment outcome. Incorporating this parameter in routine pathological diagnostics could be worthwhile to prevent overtreatment and undertreatment.

Tumor collagen framework from bright-field histology images predicts overall survival of breast carcinoma patients

Within the tumor microenvironment, specifically aligned collagen has been shown to stimulate tumor progression by directing the migration of metastatic cells along its structural framework. Tumor-associated collagen signatures (TACS) have been linked to breast cancer patient outcome. Robust and affordable methods for assessing biological information contained in collagen architecture need to be developed. We have developed a novel artificial neural network (ANN) based approach for tumor collagen segmentation from bright-field histology images and have tested it on a set of tissue microarray sections from early hormone receptor-positive invasive ductal breast carcinoma stained with Sirius Red (1 core per patient, n = 92). We designed and trained ANNs on sets of differently annotated image patches to segment collagen fibers and extracted 37 features of collagen fiber morphometry, density, orientation, texture, and fractal characteristics in the entire cohort. Independent instances of ANN models trained on highly differing annotations produced reasonably concordant collagen segmentation masks and allowed reliable prognostic Cox regression models (with likelihood ratios 14.11-22.99, at p-value < 0.05) superior to conventional clinical parameters (size of the primary tumor (T), regional lymph node status (N), histological grade (G), and patient age). Additionally, we noted statistically significant differences of collagen features between tumor grade groups, and the factor analysis revealed features resembling the TACS concept. Our proposed method offers collagen framework segmentation from bright-field histology images and provides novel image-based features for better breast cancer patient prognostication.

Stromal Cell Signature Associated with Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Breast cancer stromal compartment, may influence responsiveness to chemotherapy. Our aim was to detect a stromal cell signature (using a direct approach of microdissected stromal cells) associated with response to neoadjuvant chemotherapy (neoCT) in locally advanced breast cancer (LABC). The tumor samples were collected from 44 patients with LABC (29 estrogen receptor (ER) positive and 15 ER negative) before the start of any treatment. Neoadjuvant chemotherapy consisted of doxorubicin and cyclophosphamide, followed by paclitaxel. Response was defined as downstaging to maximum ypT1a-b/ypN0. The stromal cells, mainly composed of fibroblast and immune cells, were microdissected from fresh frozen tumor samples and gene expression profile was determined using Agilent SurePrint G3 Human Gene Expression microarrays. Expression levels were compared using MeV (MultiExperiment Viewer) software, applying SAM (significance analysis of microarrays). To classify samples according to tumor response, the order of median based on confidence statements (MedOr) was used, and to identify gene sets correlated with the phenotype downstaging, gene set enrichment analysis (GSEA). Nine patients presented disease downstaging. Eleven sequences (FDR 17) were differentially expressed, all of which (except H2AFJ) more expressed in responsive tumors, including PTCHD1 and genes involved in abnormal cytotoxic T cell physiology, TOX, LY75, and SH2D1A. The following four pairs of markers could correctly classify all tumor samples according to response: PTCHD1/PDXDC2P, LOC100506731/NEURL4, SH2D1A/ENST00000478672, and TOX/H2AFJ. Gene sets correlated with tumor downstaging (FDR < 0.01) were mainly involved in immune response or lymphocyte activation, including CD47, LCK, NCK1, CD24, CD3E, ZAP70, FOXP3, and CD74, among others. In locally advanced breast cancer, stromal cells may present specific features of immune response that may be associated with chemotherapy response.

Emerging roles of ECM remodeling processes in cancer

Extracellular matrix (ECM) plays a central and dynamic role in the creation of tumor microenvironment. Herein we discuss the emerging biophysical and biochemical aspects of ECM buildup and proteolysis in cancer niche formation. Dysregulated ECM remodeling by cancer cells facilitate irreversible proteolysis and crosslinking, which in turn influence cell signaling, micro environmental cues, angiogenesis and tissue biomechanics. Further, we introduce the emerging roles of cancer microbiome in aberrant tumor ECM remodeling and membrane bound nano-sized vesicles called exosomes in creation of distant pre-metastatic niches. A detailed molecular and biophysical understanding of the ECM morphologies and its components such as key enzymes, structural and signaling molecules are critical in identifying the next generation of therapeutic and diagnostic targets in cancer.

Stromal organization as predictive biomarker for the treatment of colon cancer with adjuvant bevacizumab; a post-hoc analysis of the AVANT trial

PURPOSE

Intra-tumoral stroma has become increasingly important in understanding tumor biology, tumor progression and clinical outcome. The amount itself, quantified as the tumor-stroma ratio (TSR), has proven to be prognostic in stage I-III colon cancer. Also, alterations in stromal organization have been found to provide prognostic and predictive information in certain cancers. Here, we evaluated the predictive value of stromal organization in high-risk stage II and III colon cancer with respect to adjuvant bevacizumab and chemotherapy.

METHODS

In a post-hoc analysis, stromal organization was microscopically determined in hematoxylin and eosin-stained primary tumor tissue samples of 1226 patients enrolled in the AVANT trial.

RESULTS

We found that patients with tumors with a disorganized stroma showed different survival rates after the addition of bevacizumab compared to standard oxaliplatin-based chemotherapy regimens. However, overall this difference was not significant with a HR of 0.94 (95% CI 0.57-1.55; p = 0.80) for disease-free survival (DFS) and 1.01 (95% CI 0.51-1.99; p = 0.99) for overall survival (OS). Subgroup analysis, however, revealed that stromal organization combined with TSR allowed the identification of stroma-high patients with absolute cumulative survival benefits up to 15% when bevacizumab was added to oxaliplatin-based chemotherapy regimens.

CONCLUSIONS

In high-risk stage II and stage III colon cancer, we found that subgroup analysis of the combined parameters stromal organization and TSR allows for the identification of patients with absolute cumulative DFS and OS benefits of up to 15%, when adding bevacizumab to the currently recommended oxaliplatin-based chemotherapy. Stromal organization itself does, however, not serve as an independent prognostic or predictive parameter.

Collagen analysis by second-harmonic generation microscopy predicts outcome of luminal breast cancer

Second-harmonic generation microscopy represents an important tool to evaluate extracellular matrix collagen structure, which undergoes changes during cancer progression. Thus, it is potentially relevant to assess breast cancer development. We propose the use of second-harmonic generation images of tumor stroma selected on hematoxylin and eosin–stained slides to evaluate the prognostic value of collagen fibers analyses in peri and intratumoral areas in patients diagnosed with invasive ductal breast carcinoma. Quantitative analyses of collagen parameters were performed using ImageJ software. These parameters presented significantly higher values in peri than in intratumoral areas. Higher intratumoral collagen uniformity was associated with high pathological stages and with the presence of axillary lymph node metastasis. In patients with immunohistochemistry-based luminal subtype, higher intratumoral collagen uniformity and quantity were independently associated with poorer relapse-free and overall survival, respectively. A multivariate response recursive partitioning model determined 12.857 and 11.894 as the best cut-offs for intratumoral collagen quantity and uniformity, respectively. These values have shown high sensitivity and specificity to differentiate distinct outcomes. Values of intratumoral collagen quantity and uniformity exceeding the cut-offs were strongly associated with poorer relapse-free and overall survival. Our findings support a promising prognostic value of quantitative evaluation of intratumoral collagen by second-harmonic generation imaging mainly in the luminal subtype breast cancer.

The value of additional bevacizumab in patients with high-risk stroma-high colon cancer. A study within the QUASAR2 trial, an open-label randomized phase 3 trial

INTRODUCTION

Patients with a high stroma percentage within the primary tumor have a poor prognosis. In this study, we investigate whether anti-angiogenic therapy might improve survival of patients with a stroma-high profile with potentially increased angiogenesis.

MATERIALS AND METHODS

Tissue samples of the primary tumor of 965 colon cancer patients participating in the QUASAR2 trial were analyzed for tumor-stroma ratio (TSR). Stroma-high (>50%) and stroma-low (≤50%) groups were evaluated with respect to survival.

RESULTS

Disease free survival (DFS) was significantly lower in the stroma-high group (HR 1.53, 95%CI 1.19-1.95, P = 0.001). No difference in DFS was seen with respect to treatment with capecitabine alone (CAP) or capecitabine with bevacizumab (CAPBEV) (Stroma-high HR 1.00, 95%CI 0.69-1.46, P = 0.996; stroma-low HR 1.02, 95%CI 0.75-1.41, P = 0.883). A significant difference in survival was seen comparing groups with or without vascular invasion (DFS P < 0.001). A correlation between vascular invasion and stroma-high was seen (χ2 -test P = 0.043).

DISCUSSION AND CONCLUSIONS

The TSR confirmed to be a strong prognosticator for disease-free survival in a selected high-risk patient population. No benefit was found in response to treatment with bevacizumab when stratified for TSR. TSR showed to have an additional prognostic value in patients with vascular invasion present in the primary tumor.

Prognostic value of tumor-stroma ratio combined with the immune status of tumors in invasive breast carcinoma

PURPOSE

Complex interactions occur between cancer cells and cells in the tumor microenvironment. In this study, the prognostic value of the interplay between tumor-stroma ratio (TSR) and the immune status of tumors in breast cancer patients was evaluated.

METHODS

A cohort of 574 breast cancer patients was analyzed. The percentage of tumor stroma was visually estimated on Hematoxylin and Eosin (H&E) stained histological tumor tissue sections. Immunohistochemical staining was performed for classical human leukocyte antigen (HLA) class I, HLA-E, HLA-G, markers for regulatory T (Treg) cells, natural killer (NK) cells and cytotoxic T-lymphocytes (CTLs).

RESULTS

TSR (P < .001) and immune status of tumors (P < .001) were both statistically significant for recurrence free period (RFP) and both independent prognosticators (P < .001) in which tumors with a high stromal content behave more aggressively as well as tumors with a low immune status. Ten years RFP for patients with a stroma-low tumor and high immune status profile was 87% compared to 17% of patients with a stroma-high tumor combined with low immune status profile (P < .001). Classical HLA class I is the most prominent immune marker in the immune status profiles.

CONCLUSIONS

Determination of TSR is a simple, fast and cheap method. The effect on RFP of TSR when combined with immune status of tumors or expression of classical HLA class I is even stronger. Both are promising for further prediction and achievement of tailored treatment for breast cancer patients.

Bisphosphonates and other bone agents for breast cancer

BACKGROUND

Bone is the most common site of metastatic disease associated with breast cancer (BC). Bisphosphonates inhibit osteoclast-mediated bone resorption, and novel targeted therapies such as denosumab inhibit other key bone metabolism pathways. We have studied these agents in both early breast cancer and advanced breast cancer settings. This is an update of the review originally published in 2002 and subsequently updated in 2005 and 2012.

OBJECTIVES

To assess the effects of bisphosphonates and other bone agents in addition to anti-cancer treatment: (i) in women with early breast cancer (EBC); (ii) in women with advanced breast cancer without bone metastases (ABC); and (iii) in women with metastatic breast cancer and bone metastases (BCBM).

SEARCH METHODS

In this review update, we searched Cochrane Breast Cancer's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 19 September 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing: (a) one treatment with a bisphosphonate/bone-acting agent with the same treatment without a bisphosphonate/bone-acting agent; (b) treatment with one bisphosphonate versus treatment with a different bisphosphonate; (c) treatment with a bisphosphonate versus another bone-acting agent of a different mechanism of action (e.g. denosumab); and (d) immediate treatment with a bisphosphonate/bone-acting agent versus delayed treatment of the same bisphosphonate/bone-acting agent.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, and assessed risk of bias and quality of the evidence. The primary outcome measure was bone metastases for EBC and ABC, and a skeletal-related event (SRE) for BCBM. We derived risk ratios (RRs) for dichotomous outcomes and the meta-analyses used random-effects models. Secondary outcomes included overall survival and disease-free survival for EBC; we derived hazard ratios (HRs) for these time-to-event outcomes where possible. We collected toxicity and quality-of-life information. GRADE was used to assess the quality of evidence for the most important outcomes in each treatment setting.

MAIN RESULTS

We included 44 RCTs involving 37,302 women.In women with EBC, bisphosphonates were associated with a reduced risk of bone metastases compared to placebo/no bisphosphonate (RR 0.86, 95% confidence interval (CI) 0.75 to 0.99; P = 0.03, 11 studies; 15,005 women; moderate-quality evidence with no significant heterogeneity). Bisphosphonates provided an overall survival benefit with time-to-event data (HR 0.91, 95% CI 0.83 to 0.99; P = 0.04; 9 studies; 13,949 women; high-quality evidence with evidence of heterogeneity). Subgroup analysis by menopausal status showed a survival benefit from bisphosphonates in postmenopausal women (HR 0.77, 95% CI 0.66 to 0.90; P = 0.001; 4 studies; 6048 women; high-quality evidence with no evidence of heterogeneity) but no survival benefit for premenopausal women (HR 1.03, 95% CI 0.86 to 1.22; P = 0.78; 2 studies; 3501 women; high-quality evidence with no heterogeneity). There was evidence of no effect of bisphosphonates on disease-free survival (HR 0.94, 95% 0.87 to 1.02; P = 0.13; 7 studies; 12,578 women; high-quality evidence with significant heterogeneity present) however subgroup analyses showed a disease-free survival benefit from bisphosphonates in postmenopausal women only (HR 0.82, 95% CI 0.74 to 0.91; P < 0.001; 7 studies; 8314 women; high-quality evidence with no heterogeneity). Bisphosphonates did not significantly reduce the incidence of fractures when compared to placebo/no bisphosphonates (RR 0.77, 95% CI 0.54 to 1.08, P = 0.13, 6 studies, 7602 women; moderate-quality evidence due to wide confidence intervals). We await mature overall survival and disease-free survival results for denosumab trials.In women with ABC without clinically evident bone metastases, there was no evidence of an effect of bisphosphonates on bone metastases (RR 0.96, 95% CI 0.65 to 1.43; P = 0.86; 3 studies; 330 women; moderate-quality evidence with no heterogeneity) or overall survival (RR 0.89, 95% CI 0.73 to 1.09; P = 0.28; 3 studies; 330 women; high-quality evidence with no heterogeneity) compared to placebo/no bisphosphonates however the confidence intervals were wide. One study reported a trend towards an extended period of time without a SRE with bisphosphonate compared to placebo (low-quality evidence). One study reported quality of life and there was no apparent difference in scores between bisphosphonate and placebo (moderate-quality evidence).In women with BCBM, bisphosphonates reduced the SRE risk by 14% (RR 0.86, 95% CI 0.78 to 0.95; P = 0.003; 9 studies; 2810 women; high-quality evidence with evidence of heterogeneity) compared with placebo/no bisphosphonates. This benefit persisted when administering either intravenous or oral bisphosphonates versus placebo. Bisphosphonates delayed the median time to a SRE with a median ratio of 1.43 (95% CI 1.29 to 1.58; P < 0.00001; 9 studies; 2891 women; high-quality evidence with no heterogeneity) and reduced bone pain (in 6 out of 11 studies; moderate-quality evidence) compared to placebo/no bisphosphonate. Treatment with bisphosphonates did not appear to affect overall survival (RR 1.01, 95% CI 0.91 to 1.11; P = 0.85; 7 studies; 1935 women; moderate-quality evidence with significant heterogeneity). Quality-of-life scores were slightly better with bisphosphonates than placebo at comparable time points (in three out of five studies; moderate-quality evidence) however scores decreased during the course of the studies. Denosumab reduced the risk of developing a SRE compared with bisphosphonates by 22% (RR 0.78, 0.72 to 0.85; P < 0.001; 3 studies, 2345 women). One study reported data on overall survival and observed no difference in survival between denosumab and bisphosphonate.Reported toxicities across all settings were generally mild. Osteonecrosis of the jaw was rare, occurring less than 0.5% in the adjuvant setting (high-quality evidence).

AUTHORS' CONCLUSIONS

For women with EBC, bisphosphonates reduce the risk of bone metastases and provide an overall survival benefit compared to placebo or no bisphosphonates. There is preliminary evidence suggestive that bisphosphonates provide an overall survival and disease-free survival benefit in postmenopausal women only when compared to placebo or no bisphosphonate. This was not a planned subgroup for these early trials, and we await the completion of new large clinical trials assessing benefit for postmenopausal women. For women with BCBM, bisphosphonates reduce the risk of developing SREs, delay the median time to an SRE, and appear to reduce bone pain compared to placebo or no bisphosphonate.

Shear-wave elastography in breast ultrasonography: the state of the art

Shear-wave elastography (SWE) is a recently developed ultrasound technique that can visualize and measure tissue elasticity. In breast ultrasonography, SWE has been shown to be useful for differentiating benign breast lesions from malignant breast lesions, and it has been suggested that SWE enhances the diagnostic performance of ultrasonography, potentially improving the specificity of conventional ultrasonography using the Breast Imaging Reporting and Data System criteria. More recently, not only has SWE been proven useful for the diagnosis of breast cancer, but has also been shown to provide valuable information that can be used as a preoperative predictor of the prognosis or response to chemotherapy.

Matrix-regulated integrin αvβ5 maintains α5β1-dependent desmoplastic traits prognostic of neoplastic recurrence

Desmoplasia, a fibrotic mass including cancer-associated fibroblasts (CAFs) and self-sustaining extracellular matrix (D-ECM), is a puzzling feature of pancreatic ductal adenocarcinoma (PDACs). Conflicting studies have identified tumor-restricting and tumor-promoting roles of PDAC-associated desmoplasia, suggesting that individual CAF/D-ECM protein constituents have distinguishable tumorigenic and tumor-repressive functions. Using 3D culture of normal pancreatic versus PDAC-associated human fibroblasts, we identified a CAF/D-ECM phenotype that correlates with improved patient outcomes, and that includes CAFs enriched in plasma membrane-localized, active α₅β₁-integrin. Mechanistically, we established that TGFβ is required for D-ECM production but dispensable for D-ECM-induced naïve fibroblast-to-CAF activation, which depends on α_vβ₅-integrin redistribution of pFAK-independent active α₅β₁-integrin to assorted endosomes. Importantly, the development of a simultaneous multi-channel immunofluorescence approach and new algorithms for computational batch-analysis and their application to a human PDAC panel, indicated that stromal localization and levels of active SMAD2/3 and α₅β₁-integrin distinguish patient-protective from patient-detrimental desmoplasia and foretell tumor recurrences, suggesting a useful new prognostic tool.

DOI:http://dx.doi.org/10.7554/eLife.20600.001

Tumors are not entirely made out of cancerous cells. They contain many other components – referred to as tumor stroma – that may either encourage or hinder the tumor’s growth. Tumor stroma includes non-cancerous cells and a framework of fibrous sugary proteins, called the extracellular matrix, which surround and signal to cells while providing physical support.

In the most common and aggressive form of pancreatic cancer, the stroma often makes up the majority of the tumor’s mass. Sometimes the stroma of these pancreatic tumors can protect the cancer cells from anti-cancer drugs. Researchers have therefore been interested in finding out exactly which aspects of the tumor stroma shield and support cancer cells, and which impede their growth and progression. Answering these questions could make it possible to develop new drugs that will change a tumor-supporting stroma into one that hinders the tumor’s growth and spread.

The most abundant cells in the stroma of pancreatic tumors are called cancer-associated fibroblasts. Healthy specialized fibroblasts – known as pancreatic stellate cells – help to build and maintain the ‘normal’ extracellular matrix and so these cells normally restrict a tumor’s development. However, cancer cells can adapt healthy fibroblasts into cancer-associated fibroblasts, which produce an altered extracellular matrix that could allow the tumor to grow.

Franco-Barraza et al. have now compared healthy and cancer-associated fibroblasts from patients’ pancreatic tumors. One of the main differences between these two cell types was the location of the activated form of a molecule called α₅β₁-integrin. Healthy fibroblasts, in a normal extracellular matrix, have active α₅β₁-integrin on the surface of the cell. However, a number of tumor-promoting signals, including some from the altered extracellular matrix, could force the active α₅β₁-integrins to relocate inside the fibroblasts instead. In further experiments, where the activated integrin was retained at the cell surface, the fibroblasts were able to resist the influence of the cancer-associated extracellular matrix. Then again, if the active α₅β₁-integrins were directed inside the cells, healthy cells turned into cancer-associated fibroblasts.

With this information in hand, Franco-Barraza et al. examined tumor samples from over a hundred pancreatic cancer patients using a new microscopy-based technique that distinguishes cancer cells from stroma cells. The analysis confirmed the pattern observed in the laboratory: those patients who appeared to produce more normal extracellular matrix and have active α₅β₁-integrin localized mostly to the surface of the cells survived longer without the cancer returning than those patients who lacked these stroma traits. Samples from patients with kidney cancer also showed similar results and, as before, an altered extracellular matrix was linked to a worse outcome of the disease.

Together these findings suggest that if future studies uncover ways to relocate or maintain active α₅β₁-integrin to the cell surface of fibroblasts they could lead to new treatments to restrict the growth of tumors in cancer patients.

DOI:http://dx.doi.org/10.7554/eLife.20600.002

Combination of shear wave elastography and Ki-67 index as a novel predictive modality for the pathological response to neoadjuvant chemotherapy in patients with invasive breast cancer

PURPOSE

This study evaluated shear wave elastography (SWE) and SWE combined with the Ki-67 index as novel predictive modalities for the pathological response of invasive breast cancer to neoadjuvant chemotherapy (NAC).

METHODS

The prospective study recruited 66 eligible patients from July 2014 to November 2015. Tumour stiffness, which corresponds with tumour progression and invasiveness, was assessed by quantitative SWE 1 d before biopsy (time point t0, elasticity E0), 1 d before next NAC cycle (t1-t5, E1-E5), and 1 d before surgery (t6, E6). The relative changes in SWE parameters after the first and second NAC cycles were considered as the variables [ΔE (t1), ΔE (t2)]. The pathological response was classified according to the residual cancer burden (RCB) protocol. Correlations between RCB scores and variables were evaluated. The predictive diagnostic performances of SWE parameters, Ki-67 index, and the predictive RCB (predRCB) score determined by a linear regression model were compared.

RESULTS

Some immunohistochemical and molecular factors and SWE parameters were significantly different among the three RCB groups. The ΔE_mean (t2) and Ki-67 had significantly better diagnostic performance than other parameters regarding predicting the pathological response (the RCB-I response and RCB-III resistance). However, the correlation between ΔE_mean (t2) and Ki-67 index was significantly weaker as a diagnostic predictor (r = 0.29). We generated a new predictive modality, predRCB, which is a multivariable linear regression model that combines ΔE_mean (t2) and the Ki-67 index. The predRCB modality showed better diagnostic performance than SWE parameters and Ki-67 index alone.

CONCLUSION

Our findings highlight the potential utility for adding the Ki-67 index to the SWE results, which may improve the predictive power of SWE and facilitate personalising the treatment regimens of patients with breast cancer. These results should be validated in the future by performing a multicentre prospective study with a larger cohort.

Collagen fibers mediate MRI-detected water diffusion and anisotropy in breast cancers

Collagen 1 (Col1) fibers play an important role in tumor interstitial macromolecular transport and cancer cell dissemination. Our goal was to understand the influence of Col1 fibers on water diffusion, and to examine the potential of using noninvasive diffusion tensor imaging (DTI) to indirectly detect Col1 fibers in breast lesions. We previously observed, in human MDA-MB-231 breast cancer xenografts engineered to fluoresce under hypoxia, relatively low amounts of Col1 fibers in fluorescent hypoxic regions. These xenograft tumors together with human breast cancer samples were used here to investigate the relationship between Col1 fibers, water diffusion and anisotropy, and hypoxia. Hypoxic low Col1 fiber containing regions showed decreased apparent diffusion coefficient (ADC) and fractional anisotropy (FA) compared to normoxic high Col1 fiber containing regions. Necrotic high Col1 fiber containing regions showed increased ADC with decreased FA values compared to normoxic viable high Col1 fiber regions that had increased ADC with increased FA values. A good agreement of ADC and FA patterns was observed between in vivo and ex vivo images. In human breast cancer specimens, ADC and FA decreased in low Col1 containing regions. Our data suggest that a decrease in ADC and FA values observed within a lesion could predict hypoxia, and a pattern of high ADC with low FA values could predict necrosis. Collectively the data identify the role of Col1 fibers in directed water movement and support expanding the evaluation of DTI parameters as surrogates for Col1 fiber patterns associated with specific tumor microenvironments as companion diagnostics and for staging.

Stromal dynamic reciprocity in cancer: intricacies of fibroblastic-ECM interactions

Stromal dynamic reciprocity (SDR) consists of the biophysical and biochemical interplay between connective tissue elements that regulate and maintain organ homeostasis. In epithelial cancers, chronic alterations of SDR result in the once tumor-restrictive stroma evolving into a 'new' tumor-permissive environment. This altered stroma, known as desmoplasia, is initiated and maintained by cancer associated fibroblasts (CAFs) that remodel the extracellular matrix (ECM). Desmoplasia fuels a vicious cycle of stromal dissemination enriching both CAFs and desmoplastic ECM. Targeting specific drivers of desmoplasia, such as CAFs, either enhances or halts tumor growth and progression. These conflicting effects suggest that stromal interactions are not fully understood. This review highlights known fibroblastic-ECM interactions in an effort to encourage therapies that will restore cancer-restrictive stromal cues.

Identification of stromal ColXα1 and tumor-infiltrating lymphocytes as putative predictive markers of neoadjuvant therapy in estrogen receptor-positive/HER2-positive breast cancer

Background

The influence of the tumor microenvironment and tumor-stromal interactions on the heterogeneity of response within breast cancer subtypes have just begun to be explored. This study focuses on patients with estrogen receptor-positive/human epidermal growth factor receptor 2-positive (ER+/HER2+) breast cancer receiving neoadjuvant chemotherapy and HER2-targeted therapy (NAC+H), and was designed to identify novel predictive biomarkers by combining gene expression analysis and immunohistochemistry with pathologic response.

Methods

We performed gene expression profiling on pre-NAC+H tumor samples from responding (no or minimal residual disease at surgery) and non-responding patients. Gene set enrichment analysis identified potentially relevant pathways, and immunohistochemical staining of pre-treatment biopsies was used to measure protein levels of those pathways, which were correlated with pathologic response in both univariate and multivariate analysis.

Results

Increased expression of genes encoding for stromal collagens, including Col10A1, and reduced expression of immune-associated genes, reflecting lower levels of total tumor-infiltrating lymphocytes (TILs), were strongly associated with poor pathologic response. Lower TILs in tumor biopsies correlated with reduced likelihood of achieving an optimal pathologic response, but increased expression of the Col10A1 gene product, colXα1, had greater predictive value than stromal abundance for poor response (OR = 18.9, p = 0.003), and the combination of increased colXα1 expression and low TILs was significantly associated with poor response in multivariate analysis. ROC analysis suggests strong specificity and sensitivity for this combination in predicting treatment response.

Conclusions

Increased expression of stromal colXα1 and low TILs correlate with poor pathologic response in ER+/HER2+ breast tumors. Further studies are needed to confirm their predictive value and impact on long-term outcomes, and to determine whether this collagen exerts a protective effect on the cancer cells or simply reflects other factors within the tumor microenvironment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2302-5) contains supplementary material, which is available to authorized users.

Disorganised stroma determined on pre-treatment breast cancer biopsies is associated with poor response to neoadjuvant chemotherapy: Results from the NEOZOTAC trial

INTRODUCTION

The tumor-associated stroma is of importance for tumor progression and is generally accepted to have a significant influence on patient prognosis. However, little is known regarding specific features of tumor-associated stromal tissues and response to (neoadjuvant) chemotherapy. This study investigated the predictive value of extracellular matrix organization on response to chemotherapy in patients treated in the NEOZOTAC trial.

METHODS

Stromal organisation was analyzed via a simple method using image analysis software on hematoxylin and eosin (H&E)-stained slides from primary tumor biopsies collected as part of the NEOZOTAC trial. Heidenhain's AZAN trichrome-stained slides were also analyzed for comparison of collagen evaluation. Sections were stained for phospho-Smad2 (pS2) in order to determine the relationship of TGF-β signaling with stromal organization.

RESULTS

A statistically significant relationship was observed between stroma consisting of organised collagen and pathological response to neoadjuvant chemotherapy (Odds Ratio 0.276, 95%CI 0.124-0.614, P = 0.002). This parameter was also related to ER-status (P = 0.003), clinical tumor -status (P = 0.041), nodal status (P = 0.029) and pS2 status (P = 0.025). Correlation between stromal organisation determined on H&E-stained and AZAN-stained tissue sections was high (Pearson's correlation coefficient = 0.806).

CONCLUSION

Intratumoral stromal organisation determined using pre-treatment breast cancer biopsies was related to pathological response to chemotherapy. This parameter might play a role in the management of breast cancer for identifying those patients that are likely to benefit from neoadjuvant chemotherapy.