The proportion of tumor-stroma as a strong prognosticator for stage II and III colon cancer patients: validation in the VICTOR trial

Prognostic impact of tumor-stroma ratio in oral squamous cell carcinoma - A pilot study

BACKGROUND

Several prognostic indicators have been used for many decades in an attempt to predict clinical behaviour of Oral Squamous Cell Carcinoma (OSCC). The prognostic value of TSR is yet to be explored in OSCC. Hence, the aim of the present study was to evaluate the prognostic value of TSR in OSCC patients.

METHODOLOGY

A cohort of 60 histologically diagnosed cases of OSCC who underwent Radical Neck Dissection was included in the study. TSR was assessed and patients with >50% intratumor stroma were quantified as the stroma-poor group and those with <50% as the stroma-rich group.

RESULTS

The parametric tests were performed for the statistical evaluation of TSR with the clinico-pathological variables and the survival. The 3-year overall survival (OS) and disease-free survival (DFS) rates were 95.23% and 69.04%, respectively, in stroma-poor group and 77% and 44%, respectively in the stroma-rich group.

CONCLUSION

TSR may serve as a reliable histologic prognostic indicator in OSCC and could be used in routine diagnostic pathology.

Predictive potential of tumour-stroma ratio on benefit from adjuvant bevacizumab in high-risk stage II and stage III colon cancer

Background

The tumour–stroma ratio (TSR) has proven to be an independent prognostic factor in colon cancer.

methods

Haematoxylin eosin tissue slides of patients from the AVANT trial were microscopically scored for TSR and categorised as stroma -low or stroma -high. Scores were correlated to the primary and secondary endpoint disease-free survival (DFS) and overall survival (OS).

Results

Patients with stroma-high tumours (N = 339, 28%) had a significantly shorter DFS (p < 0.001) compared to stroma-low tumours (N = 824, 68%). In the bevacizumab-FOLFOX-4 arm, DFS was significantly shorter compared to FOLFOX-4 in stroma-low tumours, with a hazard ratio (HR) of 1.94 (95% CI 1.24–3.04; p = 0.004). In stroma-high tumours a trend for better DFS was seen in bevacizumab-FOLFOX-4 vs. FOLFOX-4 (HR 0.61 (95% CI 0.35–1.07; p = 0.08)). For bevacizumab-XELOX vs. FOLFOX-4, this was not seen (stroma-low HR 1.07 (95% CI 0.64–1.77; p = 0.80); stroma-high HR 0.78 (95% CI 0.47–1.30; p = 0.35)). OS showed the same pattern for bevacizumab-FOLFOX-4 vs. FOLFOX-4 with a HR of 2.53 (95% CI 1.36–4.71; p = 0.003) for stroma-low and HR 0.50 (95% CI 0.22–1.14; p = 0.10) for stroma-high tumours. For bevacizumab-XELOX vs. FOLFOX-4, HR 1.13 (95% CI 0.55–2.31; p = 0.74) for stroma-low tumours and HR 0.74 (95% CI 0.37–1.51; p = 0.41) for stroma-high tumours.

Conclusions

This exploratory analysis suggests a significantly shorter DFS and OS in stroma-low tumours with addition of bevacizumab to intravenous oxaliplatin-based chemotherapy, contrary to stroma-high tumours, where a beneficial trend is observed.

MiR-650 represses high-risk non-metastatic colorectal cancer progression via inhibition of AKT2/GSK3β/E-cadherin pathway

Although 5-year survival rate of non-metastatic colorectal cancer (CRC) is high, about 10% of patients in stage I and II still develop into metastatic CRC and eventually die after resection. Currently, there is no effective biomarker for predicting the prognosis of non-metastatic CRC in clinical practice. In this study, we identified miR-650 as a biomarker for prognosis prediction. We observed that the expression of miR-650 in tumor tissues had a positive association with overall survival. MiR-650 inhibited cell growth and invasion in vitro and in vivo. Furthermore, miR-650 targeted AKT2 and repressed the activation of the AKT pathway (AKT2/GSK3β/E-cadherin). Thus it induced the translocation of E-cadherin and β-catenin in cancer cells. Our results highlight the potential of miR-650 as a prognostic prediction biomarker and therapeutic target in non-metastatic CRC via inhibition of the AKT2/GSK3β/E-cadherin pathway.

Tumor-stroma ratio predicts recurrence in patients with colon cancer treated with neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy represents a new treatment approach to locally advanced colon cancer. The aim of this study was to analyze the ability of tumor-stroma ratio (TSR) to predict disease recurrence in patients with locally advanced colon cancer treated with neoadjuvant chemotherapy.

MATERIAL AND METHODS

This study included 65 patients with colon cancer treated with neoadjuvant chemotherapy in a phase II trial. All patients were planned for three cycles of capecitabine and oxaliplatin before surgery. Hematoxylin and eosin stained tissue sections from surgically resected primary tumors were sampled and analyzed by conventional microscopy. Patients were divided into stroma-high (>50%, i.e. TSR low) and stroma-low (≤50%, i.e. TSR high) for the comparison with clinical data.

RESULTS

A low TSR was found in 47% of the surgically resected primary tumors and correlated to a significantly higher T- and N-category compared, to tumors with a high TSR (p < .01). A low TSR was also significantly associated with disease recurrence (p = .008), translating into significant differences in disease free survival (DFS) and overall survival, p < .002. The 5-year DFS rate for patients with a low TSR was 55%, compared to 94% in the group of patients with a high TSR.

CONCLUSIONS

TSR assessed in the surgically resected primary tumor from patients with locally advanced colon cancer treated with neoadjuvant chemotherapy provides prognostic value and may serve as a relevant parameter in selecting patients for post-operative treatment.

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.

The tumour-stroma ratio in colon cancer: the biological role and its prognostic impact

The tumour microenvironment consists of a complex mixture of non-neoplastic cells, including fibroblasts, immune cells and endothelial cells embedded in the proteins of the extracellular matrix. The tumour microenvironment plays an active role in tumour behaviour. By interacting with cancer cells, it influences disease progression and the metastatic capacity of the tumour. Tumours with a high amount of stroma correspond to poor patient prognosis. The tumour-stroma ratio (TSR) is a strong independent prognostic tool in colon cancer and provides additional value to the current clinically used tumour-node-metastasis classification. The TSR is assessed on conventional haematoxylin and eosin-stained paraffin sections at the invasive front of the tumour. Here we review studies demonstrating the prognostic significance of the TSR in solid epithelial tumours with a focus on colon cancer. Moreover, the biological role of the tumour microenvironment during tumour progression and invasion will be discussed, as well as the attempts to target the tumour stroma for therapeutic purposes. We suggest that the TSR can be implemented with little effort and without additional costs in current routine pathology diagnostics owing to its simplicity and reliability.

Association between tumor-stroma ratio and prognosis in solid tumor patients: a systematic review and meta-analysis

Tumor-related stroma plays an active role in tumor invasion and metastasis. The tumor–stroma ratio (TSR) in the pathologic specimen has drawn increasing attention from the field of predicting tumor prognosis. However, the prognostic value of TSR in solid tumors necessitates further elucidation. We conducted a meta-analysis on 14 studies with 4238 patients through a comprehensive electronic search on databases updated on May 2016 to explore the relationship between TSR and prognosis of solid tumors. The overall hazard ratio showed that rich stroma in tumor tissue was associated with poor overall survival (OS) (14 studies, 4238 patients) and disease-free survival (DFS) (9 studies, 2235 patients) of patients with solid tumors. The effect of low TSR on poor OS was observed among various cancer types, but not in the early stage of cervical caner. A significant relationship between low TSR and poor OS was also observed in the subgroup analyses based on study region, blinding status, and Newcastle–Ottawa Scale (NOS) score. Subgroup analyses indicated that cancer type, clinical stage, study region, blinding status, and NOS score did not affect the prognostic value of TSR for DFS. Moreover, low TSR was significantly correlated with the serious clinical stage, advanced depth of invasion, and positive lymph node metastasis. These findings indicate that a high proportion of stroma in cancer tissue is associated with poor clinical outcomes in cancer patients, and TSR may serve as an independent prognostic factor for solid tumors.

Does heterogeneity matter in the estimation of tumour budding and tumour stroma ratio in colon cancer?

Background

Tumour budding (TB) and Tumour Stroma Ratio (TSR) may be rewarding in the treatment stratification of patients with stage II colon cancer. However, lack of standardization may exclude these parameters from being used in a clinical setting. The purpose of this methodologic study was to compare stereology with semi-quantitative estimations of TSR, to investigate the intra-tumoural heterogeneity of TB and TSR, and to assess the intra- and inter-observer agreement.

Methods

Three paraffin embedded tumour blocks, one of them representing the deepest invasive front, were selected from each of 43 patients treated for stage II colon cancer. TSR was estimated in H&E sections semi-quantitatively using conventional microscopy, and stereologically on scanned slides, using the newCAST stereology platform. TB was scored across 10 high power fields at the invasive front in cytokeratin AE1/AE3 stained sections.

Results

Subjective, semi-quantitative estimates of TSR significantly correlated to the stereological estimates, with the best correlation found for sections with the deepest invasive tumour penetration (σ = 0.621, p < 0.001). Inter-observer agreement was moderate to substantial for both TB (Κappa = 0.46–0.73) and TSR (Κappa = 0.70–0.75).

The Intraclass correlation coefficient (ICC) for TSR varied from 0.322 based on stereological hotspot estimation to 0.648 for the semi-quantitative evaluation. For TB, ICC varied from 0.646 based on continuous data to 0.698 based on categorical data (cut-off: 10 buds). Thus, the intra-tumoural heterogeneity for both TB and the semi-quantitative estimation of TSR was low.

Conclusion

We recommend using only one tissue section representing the deepest invasive tumour area for estimation of TSR. For TB we recommend using one tissue section; however due to low representation of high-budding tumours, results must be considered with caution.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0697-9) contains supplementary material, which is available to authorized users.

Unveiling a CD70-positive subset of cancer-associated fibroblasts marked by pro-migratory activity and thriving regulatory T cell accumulation

Cancer-associated fibroblasts (CAFs) are involved in the proliferative and invasive behavior of colorectal cancer (CRC). Nonetheless, CAFs represent a heterogeneous population with both cancer-promoting and cancer-restraining actions, lacking specific markers to target them. Expression of the immune checkpoint molecule CD70 is normally limited to cells of the lymphoid lineage. Instead, tumor cells hijack CD70 to facilitate immune evasion by increasing the amount of suppressive regulatory T cells (Tregs). The aim of this study was to explore CD70 expression patterns in CRC, not merely focusing on the tumor cells, but also taking the tumor stromal cells into account. We have analyzed the prognostic value of CD70 expression by immunohistochemistry in CRC specimens and its relationship with well-known fibroblast markers and Tregs. In addition, in vitro experiments were conducted to unravel the role of CD70-positive CAFs on migration and immune escape. We reveal prominent expression of CD70 on a specific subset of CAFs in invasive CRC specimens. Cancer cells show almost no expression of CD70. The presence of CD70-positive CAFs proved to be an independent adverse prognostic marker. Functionally, CD70-positive CAFs stimulated migration and significantly increased the frequency of naturally occurring Tregs. In conclusion, we have identified the expression of CD70 on CAFs as a novel prognostic marker for CRC. We have found evidence of a cross talk between CD70⁺ CAFs and naturally occurring Tregs, paving the way towards immune escape. As such, this study provides a strong rationale for the exploration of CD70-targeting antibodies in CRC.

Prognostic markers for colorectal cancer: estimating ploidy and stroma

Background

We report here the prognostic value of ploidy and digital tumour-stromal morphometric analyses using material from 2624 patients with early stage colorectal cancer (CRC).

Patients and methods

DNA content (ploidy) and stroma-tumour fraction were estimated using automated digital imaging systems and DNA was extracted from sections of formalin-fixed paraffin-embedded (FFPE) tissue for analysis of microsatellite instability. Samples were available from 1092 patients recruited to the QUASAR 2 trial and two large observational series (Gloucester, n = 954; Oslo University Hospital, n = 578). Resultant biomarkers were analysed for prognostic impact using 5-year cancer-specific survival (CSS) as the clinical end point.

Results

Ploidy and stroma-tumour fraction were significantly prognostic in a multivariate model adjusted for age, adjuvant treatment, and pathological T-stage in stage II patients, and the combination of ploidy and stroma-tumour fraction was found to stratify these patients into three clinically useful groups; 5-year CSS 90% versus 83% versus 73% [hazard ratio (HR) = 1.77 (95% confidence interval (95% CI): 1.13-2.77) and HR = 2.95 (95% CI: 1.73-5.03), P < 0.001].

Conclusion

A novel biomarker, combining estimates of ploidy and stroma-tumour fraction, sampled from FFPE tissue, identifies stage II CRC patients with low, intermediate or high risk of CRC disease specific death, and can reliably stratify clinically relevant patient sub-populations with differential risks of tumour recurrence and may support choice of adjuvant therapy for these individuals.

Novel histopathologic feature identified through image analysis augments stage II colorectal cancer clinical reporting

A number of candidate histopathologic factors show promise in identifying stage II colorectal cancer (CRC) patients at a high risk of disease-specific death, however they can suffer from low reproducibility and none have replaced classical pathologic staging. We developed an image analysis algorithm which standardized the quantification of specific histopathologic features and exported a multi-parametric feature-set captured without bias. The image analysis algorithm was executed across a training set (n = 50) and the resultant big data was distilled through decision tree modelling to identify the most informative parameters to sub-categorize stage II CRC patients. The most significant, and novel, parameter identified was the ‘sum area of poorly differentiated clusters’ (AreaPDC). This feature was validated across a second cohort of stage II CRC patients (n = 134) (HR = 4; 95% CI, 1.5– 11). Finally, the AreaPDC was integrated with the significant features within the clinical pathology report, pT stage and differentiation, into a novel prognostic index (HR = 7.5; 95% CI, 3–18.5) which improved upon current clinical staging (HR = 4.26; 95% CI, 1.7– 10.3). The identification of poorly differentiated clusters as being highly significant in disease progression presents evidence to suggest that these features could be the source of novel targets to decrease the risk of disease specific death.

The prognostic value of tumour stroma ratio and tumour budding in stage II colon cancer. A nationwide population-based study

PURPOSE

High-risk patients with stage II colon cancer (CC) may benefit from adjuvant chemotherapy, but additional prognostic markers are needed for better stratification. We investigated the prognostic value of tumour stroma ratio (TSR) and tumour budding (TB).

METHODS

A nationwide population-based cohort of 573 patients with stage II CC was included. TSR was scored on hematoxylin and eosin sections as low TSR (> 50% stroma) and high TSR (≤ 50% stroma). TB was evaluated in hotspots on pan-cytokeratin stained sections in 10 high power fields (HPF) at the invasive front and classified by the mean number of buds per HPF as high grade budding (≥ 10 buds) or low-grade budding (< 10 buds). The prognostic value was investigated in Cox proportional hazard models for recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Low TSR was associated with worse RFS (HR = 1.342 (95% CI 1.006-1.791), p = 0.045) and OS (HR = 1.376 (95% CI 1.016-1.862), p = 0.039). Furthermore, an association was found between low TSR and microsatellite stabile tumours (p < 0.001). The mean number of buds per HPF was associated to TSR with increasing number of buds related to a lower TSR (p = 0.026). No statistically significant prognostic impact of TB regarding OS or RFS was detected.

CONCLUSIONS

TSR provided valuable prognostic information, and adding TSR to the current risk stratification may contribute to better patient selection. The estimates of TSR and TB were found to be associated, but no prognostic value of TB was documented.

The tumor-stromal ratio as a strong prognosticator for advanced gastric cancer patients: proposal of a new TSNM staging system

BACKGROUND

Insufficient attention is paid to the underlying tumor microenvironment (TME) evolution, that resulting in tumor heterogeneity and driving differences in cancer aggressiveness and treatment outcomes. The morphological evaluation of the proportion of the stroma at the most invasive part of primary tumor (tumor-stromal ratio, TSR) in cancer is gaining momentum as evidence strengthens for the clinical relevance.

METHODS

Tissue samples from the most invasive part of the primary gastric cancer (GC) of 494 patients were analyzed for their TSR, and a new TSNM (tumor-stromal node metastasis) staging system based on patho-biological behaviors was established and assessed.

RESULTS

TSR is a new and strong independent prognostic factor for GC patients. The likelihood of tumor invasion is increased significantly for patients in the stromal-high subgroup compared to those in the stromal-low subgroup (P = 0.011). The discrimination ability of TSR was not less than the TNM staging system and was better in patients with stages I and II GC. We integrated the TSR parameter into the TNM staging system and proposed a new TSNM staging system creatively. There were three new subgroups (IC, IIC, IIID). There were four major groups and 10 subgroups in the TSNM system. The difference in overall survival (OS) was statistically significant among all TSNM system (P < 0.005 for all). Deep analyses revealed well predictive performance of the TSNM (P < 0.001).

CONCLUSIONS

This study confirms the TSR as a TME prognostic factor for GC. TSR is a candidate TME parameter that could easily be implemented in routine pathology diagnostics, and the TSNM staging system has been established to optimize risk stratification for GC. The value of the TSNM staging system should be validated in further prospective study.

Radiotherapy-Activated Cancer-Associated Fibroblasts Promote Tumor Progression through Paracrine IGF1R Activation

Preoperative radiotherapy (RT) is a mainstay in the management of rectal cancer, a tumor characterized by desmoplastic stroma containing cancer-associated fibroblasts (CAF). Although CAFs are abundantly present, the effects of RT to CAF and its impact on cancer cells are unknown. We evaluated the damage responses of CAF to RT and investigated changes in colorectal cancer cell growth, transcriptome, metabolome, and kinome in response to paracrine signals emerging from irradiated CAF. RT to CAF induced DNA damage, p53 activation, cell-cycle arrest, and secretion of paracrine mediators, including insulin-like growth factor-1 (IGF1). Subsequently, RT-activated CAFs promoted survival of colorectal cancer cells, as well as a metabolic switch favoring glutamine consumption through IGF1 receptor (IGF1R) activation. RT followed by IGF1R neutralization in orthotopic colorectal cancer models reduced the number of mice with organ metastases. Activation of the downstream IGF1R mediator mTOR was significantly higher in matched (intrapatient) samples and in unmatched (interpatient) samples from rectal cancer patients after neoadjuvant chemoradiotherapy. Taken together, our data support the notion that paracrine IGF1/IGF1R signaling initiated by RT-activated CAF worsens colorectal cancer progression, establishing a preclinical rationale to target this activation loop to further improve clinical responses and patient survival.Significance: These findings reveal that paracrine IGF1/IGF1R signaling promotes colorectal cancer progression, establishing a preclinical rationale to target this activation loop. Cancer Res; 78(3); 659-70. ©2017 AACR.

QuPath: Open source software for digital pathology image analysis

QuPath is new bioimage analysis software designed to meet the growing need for a user-friendly, extensible, open-source solution for digital pathology and whole slide image analysis. In addition to offering a comprehensive panel of tumor identification and high-throughput biomarker evaluation tools, QuPath provides researchers with powerful batch-processing and scripting functionality, and an extensible platform with which to develop and share new algorithms to analyze complex tissue images. Furthermore, QuPath's flexible design makes it suitable for a wide range of additional image analysis applications across biomedical research.

QuPath: Open source software for digital pathology image analysis

QuPath is new bioimage analysis software designed to meet the growing need for a user-friendly, extensible, open-source solution for digital pathology and whole slide image analysis. In addition to offering a comprehensive panel of tumor identification and high-throughput biomarker evaluation tools, QuPath provides researchers with powerful batch-processing and scripting functionality, and an extensible platform with which to develop and share new algorithms to analyze complex tissue images. Furthermore, QuPath's flexible design makes it suitable for a wide range of additional image analysis applications across biomedical research.

Stromal and intraepithelial tumor-infiltrating lymphocytes in colorectal carcinoma

The local mechanisms of antitumor immune defense determine the development and organization of the tumor microenvironment, and the composition and relative proportions of the inflammatory cell population affect the quality and characteristics of the immune response. The aim of the present study was to conduct a quantitative morphological evaluation of two types of tumor-infiltrating lymphocyte (TILs) populations, including those located in the stroma and intraepithelial cancer structures, in the invasive front and the center of the tumor in patients with colorectal cancer (CRC). The study included 160 patients with CRC who had undergone surgery. The tissue material was stained with hematoxylin and eosin, as used in routine histopathological diagnosis, and the two TIL populations were observed and counted with light microscopy. The relative extent of infiltration of stromal and intraepithelial TILs into the front and center of the primary tumors was similar. The extent of infiltration by stromal TILs was negatively correlated with the morphological features of tumor progression including the cancer infiltration of blood vessels (P=0.016), the invasion of lymph vessels (P=0.007), perineural invasion (P=0.036), lymph node involvement (P=0.047) and distant metastases (P=0.032). The infiltration by intraepithelial TILs was positively correlated with a desmoplastic reaction (P=0.002). Disease-free survival time was statistically shorter in patients without intraepithelial TILs in the center of the primary tumor mass (P=0.049; hazard ratio = 1.45). These results confirm that the infiltration of TILs into the invasive front and center of the tumor in patients with CRC serves an important role in the invasion and progression of the disease, and should be considered in routine histopathological examinations.

Intratumoral stromal morphometry predicts disease recurrence but not response to 5-fluorouracil-results from the QUASAR trial of colorectal cancer

AIMS

The biological importance of tumour-associated stroma is becoming increasingly apparent, but its clinical utility remains ill-defined. For stage II/Dukes B colorectal cancer (CRC), clinical biomarkers are urgently required to direct therapeutic options. We report here prognostic/predictive analyses, and molecular associations, of stromal morphometric quantification in the Quick and Simple and Reliable (QUASAR) trial of CRC.

METHODS AND RESULTS

Relative proportions of tumour epithelium (PoT) or stroma (PoS) were morphometrically quantified on digitised haematoxylin and eosin (H&E) sections derived from 1800 patients enrolled in QUASAR, which randomised 3239 (91% stage II) CRC patients between adjuvant fluorouracil/folinic acid (FUFA) chemotherapy and observation. The prognostic and predictive values of PoT/PoS measurements were determined by the use of stratified log-rank analyses. A high proportion of tumour stroma (≥50%) was associated with an increased recurrence risk: 31.3% (143/457) recurrence for ≥50% versus 21.9% (294/1343) for <50% [rate ratio (RR) 1.62; 95% confidence interval (CI) 1.30-2.02; P < 0.0001]. Of patients with stromal proportions of ≥65%, 40% (46/115) had recurrent disease within 10 years. The adverse prognostic effect of a high stromal proportion was independent of established prognostic variables, and was maintained in stage II/Dukes B patients (RR 1.62; 95% CI 1.26-2.08; P = 0.0002). KRAS mutation in the presence of a high stromal proportion augmented recurrence risk (RR 2.93; 95% CI 1.87-4.59; P = 0.0005). Stromal morphometry did not predict response to FUFA chemotherapy.

CONCLUSIONS

Simple digital morphometry applied to a single representative H&E section identifies CRC patients with a >50% higher risk of disease recurrence. This technique can reliably partition patients into subpopulations with different risks of tumour recurrence in a simple and cost-effective manner. Further prospective validation is warranted.

Disentangling the prognostic heterogeneity of stage III colorectal cancer through histologic stromal categorization

BACKGROUND

Growing evidence suggests the importance of stroma in determining cancer biology and recent studies have identified that genes closely associated with poor prognosis subtypes of colorectal cancer are expressed by the stroma rather than epithelial cancer cells. We aimed to clarify the prognostic value of the novel histologic classification of desmoplastic reaction in stage III colorectal cancer.

METHODS

A pathologic review was conducted for 466 stage III colorectal cancer patients in a single Japanese institution (1999-2006). Desmoplastic reaction was classified as mature, intermediate, or immature according to existence of hyalinized collagen bundles and myxoid stroma, both appear exclusively at the desmoplastic front. An additional 432 patients treated at four independent institutions (2007-2008) were examined as a second cohort to validate the results.

RESULTS

According to desmoplastic reaction, 164, 133, and 169 patients were classified as mature, intermediate, and immature, respectively. Five-year relapse-free survival rates were highest in the mature group (86.0%), followed by the intermediate (73.7%) and immature (50.9%) groups. An adverse prognostic impact of desmoplastic reaction was invariably observed in stage IIIB, which contained 71% of stage III cases. Harrell's concordance index for relapse-free survival was greater in desmoplastic reaction (0.66) than any conventional tumor-associated prognostic factors including tumor node metastasis substage (0.62) and tumor grade (0.53). Similar results were observed in the second cohort, wherein desmoplastic reaction categorization was the most influential prognostic factor.

CONCLUSION

Histologic desmoplastic reaction categorization could be a key to solve the issue of prognostic heterogeneity in stage III colorectal cancer, thereby enhancing the value of tumor node metastasis stage.

Desmoplastic Pattern at the Tumor Front Defines Poor-prognosis Subtypes of Colorectal Cancer

Although recent findings of cancer biology research indicate that prognostic power arises from genes expressed by stromal cells rather than epithelial cells, desmoplastic reaction (DR) has not been completely examined as a prognostic marker for colorectal cancer. A pathologic review of 821 stage II and III patients who underwent R0 resection for colorectal cancer at 4 independent institutions was conducted. DR was classified as mature, intermediate, or immature based on the existence of hyalinized keloid-like collagen and myxoid stroma at the extramural desmoplastic front. Totally, 325, 282, and 214 patients were classified as having mature, intermediate, and immature DR, respectively. DR significantly influenced the recurrence rate in the liver, lung, and peritoneum (P≤0.0001 to 0.01). Five-year relapse-free survival (RFS) rate was the highest in the mature group (85.7%), followed by the intermediate (77.3%) and immature (50.4%) groups. A significant adverse impact of immature stroma on RFS was observed in subset analyses of the 4 institutions. Multivariate analysis revealed that DR, along with T and N stages, is an independent prognostic factor. On the basis of Harrell's concordance index, the prognostic power of DR categorization (0.67) in stratifying RFS was greater than any other conventional prognostic factors, including TNM (0.64), N (0.62) and T stages (0.59), venous invasion (0.59), and tumor grade (0.54). Characterizing DR based on the histologic products of activated fibroblasts is valuable for evaluating prognostic outcomes. To our knowledge, this is the first study reporting a greater prognostic power of histology of the fibrotic stroma than that of tumor factors.

Tumor-stroma ratio (TSR) in non-small cell lung cancer (NSCLC) patients after lung resection is a prognostic factor for survival

Background

In recent years, the tumor-stroma ratio (TSR) has been considered to a new and independent predictive variable for the prognosis of some kinds of neoplasms. The objective of this study was to assess the prognostic significance of the TSR in non-small cell lung cancer (NSCLC).

Methods

A cohort of 261 NSCLC patients who underwent radical surgery of lung cancer were included in the present study. Two independent observers visually estimated the TSR on hematoxylin-eosin (H&E) stained tissue pathological slices. According to the proportion of stroma ≥50% or <50%, We separate the patients into two groups: those with stroma-poor and those with stroma-rich tumors.

Results

Both univariate and multivariate analyses disclosed that the TSR was associated with overall survival (OS) [hazard ratio (HR), 1.741; 95% confidence intervals (CI), 1.040-2.913 and HR, 1.904; 95% CI, 1.132-3.202, respectively]. The HR values for disease-free survival (DFS) were 1.795 (95% CI, 1.073-3.005) and 2.034 (95% CI, 1.210-3.420). The OS and DFS of patients with stroma-poor tumors were better than those with stroma-rich tumors.

Conclusions

These results demonstrated that the TSR is a new prognostic factor for NSCLC. Stroma-poor tumors were associated with longer disease-free period and better prognosis than were stroma-rich tumors in NSCLC patients. The TSR may contribute to the development of individualized treatment for NSCLC in the future.

Imaging Tunneling Membrane Tubes Elucidates Cell Communication in Tumors

Intercellular communication is a vital yet underdeveloped aspect of cancer pathobiology. This Opinion article reviews the importance and challenges of microscopic imaging of tunneling nanotubes (TNTs) in the complex tumor microenvironment. The use of advanced microscopy to characterize TNTs in vitro and ex vivo, and related extensions called tumor microtubes (TMs) reported in gliomas in vivo, has propelled this field forward. This topic is important because the identification of TNTs and TMs fills the gap in our knowledge of how cancer cells communicate at long range in vivo, inducing intratumor heterogeneity and resistance to treatment. Here we discuss the concept that TNTs/TMs fill an important niche in the ever-changing microenvironment and the role of advanced microscopic imaging to elucidate that niche.

Tumour infiltrating lymphocytes are predictors of lymph node metastasis in early gastric cancers

Lymph node metastasis (LNM) is an important factor for predicting prognosis and selecting appropriate treatment in early gastric cancers (EGCs). We investigated the histopathological and microenvironmental predictors of LNM in EGCs. We retrieved 43 cases of EGC without LNM and 59 cases with LNM. Clinicopathological variables and tumour-infiltrating lymphocytes (TILs), Crohn's-like lymphoid reaction (CLR), tumour stromal percentage (TSP), and FOXA1 expression were evaluated and correlated with LNM. Among the 102 cases, 68 cases (66.7%) had low TILs and 34 cases (33.3%) had high TILs. High TILs were significantly correlated with the absence of LNM (p<0.001), less extent of invasion (p=0.004), absence of LVI (p=0.035), conspicuous CLR (p<0.001), and the absence of TSP (p=0.009). Conspicuous CLR was observed in 47 cases (46.1%) and TSP was present in 17 cases (16.7%) and neither was correlated with LNM. High FOXA1 expression was significantly associated with presence of LNM, low TILs, and submucosal invasion. In multivariate analysis, low TILs (p=0.023), LVI (p=0.008), and submucosal invasion (p=0.001) were independent predictive factors for LNM in EGCs. Evaluation of TILs in biopsied or endoscopically resected EGC specimens may help to predict LNM and select subsequent proper treatment modalities and follow-up.

Diagnostic value of inflammatory cell infiltrates, tumor stroma percentage and disease-free survival in patients with colorectal cancer

The anticancer immune defense mechanism involves humoral and cellular responses. The main effector mechanisms of antitumor responses involve the following: the activity of cytotoxic T cells; the activation of macrophages and neutrophils; the activity of cytokines secreted by T cells; and natural killer cell activity. Selected cell populations are responsible for the stimulation or suppression of the immune system against tumor cells. Therefore, the aim of the present study was to evaluate the location, extent and composition of the cellular inflammatory infiltration of tumors in patients with colorectal cancer (CRC). In addition, the correlation between cellular inflammatory infiltration, and anatomoclinical and histopathological features of patients was evaluated. The study involved 160 patients diagnosed with primary operable CRC. The local inflammatory infiltrate was assessed in the invasive front and center of the tumor using light microscopy with hematoxylin and eosin (H&E) staining, according to the Klintrup-Makinen criteria, tumor stroma percentage, and Glasgow microenvironment score. The inflammatory infiltrate in the invasive front of the tumor was correlated with gender (P=0.018), the invasion of blood vessels (P=0.020) and lymph vessels (P=0.038), the presence of tumor-infiltrating lymphocytes in the invasive front (P=0.033) and center (P<0.001) of the tumor, fibrosis (P<0.001), and the degree of desmoplasmic stroma (P=0.004). In contrast, inflammatory infiltration in the center of the tumor was associated with the tumor node metastasis stage (P=0.012), Dukes' stage (P=0.009), primary tumor stage (P=0.036), lymph node status (P=0.005), number of lymph nodes (P=0.006), invasion of lymph node pouches (P=0.021), size of lymph node metastasis (P=0.025) and the degree of desmoplasmic stroma (P=0.002). The low-group, who demonstrated an absent or weak inflammatory cell infiltrate in the invasive front of the tumor, had a statistically significant shorter disease-free survival (DFS) time (P=0.004). Inflammatory cell infiltrate in the invasive front was identified as an independent predictive factor in CRC (P=0.041). In conclusion, the degree of inflammatory cell infiltration in the invasive front of the primary tumor significantly affects various variables that determine disease progression and DFS rates of patients with CRC. Furthermore, the routine histopathological assessment of this parameter in tissue stained with H&E may have potential prognostic value.

Tumor-stroma ratio(TSR) as a potential novel predictor of prognosis in digestive system cancers: A meta-analysis

MAIN PROBLEM

The tumor-stroma ratio (TSR) has been reported as a prognosis predictor in multiple cancers. The aim of this meta-analysis was to investigate the potential value of TSR as a prognostic predictor of cancer in the digestive system.

METHODS

We searched PubMed, Embase, Elsevier and Web of Science. All studies exploring the association of TSR with overall survival (OS) or disease-free survival (DFS), and lymph node metastasis (LNM) were identified.

RESULTS

In total, eight studies were eligible for analysis, and they included 1959 patients. Meta-analysis showed that the low TSR in the tumor could predict poor overall survival (OS) in multiple cancers (pooled Hazard Ratio [HR]: 2.15, 95%CI: 1.80-2.57, P<0.00001, fixed effects). For disease-free survival (DFS), low TSR was also a significant predictor (pooled Hazard Ratio [HR]: 2.31, 95%CI: 1.88-2.83, P<0.00001, fixed effects). In addition, low TSR was correlated with tumor stage.

DISCUSSION

The tumor-stroma ratio (TSR) may potentially serve as a poor prognostic predictor for the metastasis and prognosis of cancer.

Back to the future: routine morphological assessment of the tumour microenvironment is prognostic in stage II/III colon cancer in a large population-based study

AIMS

Both morphological and molecular approaches have highlighted the biological and prognostic importance of the tumour microenvironment in colorectal cancer (CRC). Despite this, microscopic assessment of the tumour microenvironment has not been adopted into routine practice. The study aim was to identify those tumour microenvironmental features that are most likely to provide prognostic information and be feasible to use in routine pathology reporting practice.

METHODS AND RESULTS

On the basis of existing evidence, we selected specific morphological features relating to peritumoral inflammatory and stromal responses, agreed criteria for scoring, and assessed these in representative haematoxylin and eosin (H&E)-stained whole tumour sections from a population-based cohort of 445 stage II/III colon cancer cases. Moderate/severe peritumoral diffuse lymphoid inflammation and Crohn's disease-like reaction were associated with significantly reduced risks of CRC-specific death [adjusted hazard ratio (HR) 0.48, 95% confidence interval (CI) 0.31-0.76, and HR 0.60, 95% CI 0.42-0.84, respectively]. The presence of >50% tumour stromal percentage, as assessed by global evaluation of tumour area, was associated with a significantly increased risk of CRC-specific death (HR 1.60 95% CI 1.06-2.41). A composite 'fibroinflammatory score' (0-3), combining dichotomized scores of these three features, showed a highly significant association with survival outcomes. Those with a score of ≥2 had an almost 2.5-fold increased risk of CRC-specific death (HR 2.44, 95% CI 1.56-3.81) as compared with those scoring zero. These associations were stronger in microsatellite instability (MSI)-high tumours, potentially identifying a subset of MSI-high colon cancers that lack characteristic morphological features and have an associated worse prognosis.

CONCLUSIONS

In summary, reporting on H&E staining of selected microscopic features of the tumour microenvironment, independently or in combination, offers valuable prognostic information in stage II/III colon cancer, and may allow morphological correlation with developing molecular classifications of prognostic and predictive relevance.

Tumor-Stroma Ratio is an independent predictor for overall survival and disease free survival in gastric cancer patients

BACKGROUND

Despite different prognostic factors have been already studied, patients undergoing potentially curative resection for gastric cancer, still have a poor outcome. There is therefore the need to identify novel prognostic factors. Recently, Tumor-Stroma Ratio (TSR) was proven to be associated with prognosis in different types of cancers. Aim of this study was to evaluate the prognostic value of TSR in gastric cancer patients.

METHODS

106 patients underwent gastrectomy between January 2004 and December 2015. Demographics and histopathological characteristics were collected. We considered a 50% TSR cutoff value to divide patients in Stroma-Rich (≥50%) and Stroma-Poor (<50%) groups.

RESULTS

Forty-one (38.7%) patients were classified as Stroma-Poor while 65 (61.3%) as Stroma-Rich (61.3%). The Stroma-Rich patients had a higher number of positive lymph-nodes, lymph node ratio (LNR), a higher percentage of T3/T4 local invasion and N2/N3, and a more advanced TNM. Moreover, these patients showed a higher percentage of lymphovascular and perineural invasion. With a median FU of 38 months Stroma-Rich patients had a significantly worse 5-years actuarial overall survival (OS) and disease free survival (DFS) compared to Stroma-Poor patients. Moreover, the multivariate analysis showed that Stroma-Rich was the only independent factor associated with OS and DFS together with TNM-Stage.

CONCLUSIONS

TSR is an independent marker of poor prognosis in patients with gastric cancer that should be readily incorporated into routine clinical pathology reporting. Identification of sensitive markers for patients who had undergone curative gastrectomy and who are at high risk of recurrence could provide useful information for planning follow-up after surgery or intensive and or/targeting adjuvant chemotherapy.

Tumour invasiveness, the local and systemic environment and the basis of staging systems in colorectal cancer

Background:

The present study aimed to examine the relationship between tumour invasiveness (T stage), the local and systemic environment and cancer-specific survival (CSS) of patients with primary operable colorectal cancer.

Methods:

The tumour microenvironment was examined using measures of the inflammatory infiltrate (Klintrup-Makinen (KM) grade and Immunoscore), tumour stroma percentage (TSP) and tumour budding. The systemic inflammatory environment was examined using modified Glasgow Prognostic Score (mGPS) and neutrophil:lymphocyte ratio (NLR). A 5-year CSS was examined.

Results:

A total of 331 patients were included. Increasing T stage was associated with colonic primary, N stage, poor differentiation, margin involvement and venous invasion (P<0.05). T stage was significantly associated with KM grade (P=0.001), Immunoscore (P=0.016), TSP (P=0.006), tumour budding (P<0.001), and elevated mGPS and NLR (both P<0.05). In patients with T3 cancer, N stage stratified survival from 88 to 64%, whereas Immunoscore and budding stratified survival from 100 to 70% and from 91 to 56%, respectively. The Glasgow Microenvironment Score, a score based on KM grade and TSP, stratified survival from 93 to 58%.

Conclusions:

Although associated with increasing T stage, local and systemic tumour environment characteristics, and in particular Immunoscore, budding, TSP and mGPS, are stage-independent determinants of survival and may be utilised in the staging of patients with primary operable colorectal cancer.

Tenascin-C is a potential cancer-associated fibroblasts marker and predicts poor prognosis in prostate cancer

Tenascin-C (TNC), as a member of the extracellular matrix (ECM), plays an important role in cancer cell proliferation and migration and tumor invasion in various types of cancer. Here, we attempted to investigate the role of TNC as a prognostic factor in prostate cancer. We studied TNC expression via immunohistochemistry in 145 prostate cancer tissue samples. The clinicopathological relevance of TNC expression was examined, as well as other cancer-associated fibroblasts (CAFs)-related factors. Our results showed that the high levels of TNC expression in prostate cancer stroma was significantly associated with lymph node metastasis (P = 0.024) and clinical stage (P = 0.032). Furthermore, TNC was positively correlated with increased micro-vessel density (MVD) (P = 0.017) and tumor associated macrophage (TAM) population (P = 0.025). In both univariate and multivariate Cox regression analyses, TNC (P < 0.001) was an independent poor prognostic factor for overall survival in prostate cancer patients. Moreover, over-expression of TNC (P < 0.001), SMA (P = 0.042) and vimentin (P = 0.010) were significantly correlated with the lower overall survival. In addition, TNC expression in prostate cancer stroma was significantly associated with FSP1 (P = 0.011), SMA (P = 0.021), and vimentin (P = 0.002). In conclusion, our study revealed that high level of TNC as a potential biomarker of CAFs was significantly correlated with the poor prognosis for prostate cancer patients.

Tunneling nanotubes: an alternate route for propagation of the bystander effect following oncolytic viral infection

Tunneling nanotubes (TNTs) are ultrafine, filamentous actin-based cytoplasmic extensions which form spontaneously to connect cells at short and long-range distances. We have previously described long-range intercellular communication via TNTs connecting mesothelioma cells in vitro and demonstrated TNTs in intact tumors from patients with mesothelioma. Here, we investigate the ability of TNTs to mediate a viral thymidine kinase based bystander effect after oncolytic viral infection and administration of the nucleoside analog ganciclovir. Using confocal microscopy we assessed the ability of TNTs to propagate enhanced green fluorescent protein (eGFP), which is encoded by the herpes simplex virus NV1066, from infected to uninfected recipient cells. Using time-lapse imaging, we observed eGFP expressed in infected cells being transferred via TNTs to noninfected cells; additionally, increasing fluorescent activity in recipient cells indicated cell-to-cell transmission of the eGFP-expressing NV1066 virus had also occurred. TNTs mediated cell death as a form of direct cell-to-cell transfer following viral thymidine kinase mediated activation of ganciclovir, inducing a unique long-range form of the bystander effect through transmission of activated ganciclovir to nonvirus-infected cells. Thus, we provide proof-of-principle demonstration of a previously unknown and alternative mechanism for inducing apoptosis in noninfected recipient cells. The conceptual advance of this work is that TNTs can be harnessed for delivery of oncolytic viruses and of viral thymidine kinase activated drugs to amplify the bystander effect between cancer cells over long distances in stroma-rich tumor microenvironments.

Tumour-associated mesenchymal stem/stromal cells: emerging therapeutic targets

Mesenchymal stem cells, also known as mesenchymal stromal cells (MSCs), exist in many tissues and are known to actively migrate to sites of tissue injury, where they participate in wound repair. Tumours can be considered "wounds that never heal" and, in response to cues from a tumour, MSCs are continuously recruited to and become integral components of the tumour microenvironment. Recently, it has become apparent that such tumour-associated MSCs (TA-MSCs) have an active role in tumour initiation, promotion, progression and metastasis. In this Review, we discuss recent advances in our understanding of the pathogenic role of TA-MSCs in regulating the survival, proliferation, migration and drug resistance of tumour cells, as well as the influence of MSCs on the immune status of the tumour microenvironment. Moreover, we discuss therapeutic approaches that target TA-MSC upstream or downstream modulators or use MSCs as vehicles for the delivery of tumoricidal agents. It is anticipated that new insights into the functions of TA-MSCs will lead to the development of novel therapeutic strategies against tumours.

A pilot study exploring the molecular architecture of the tumor microenvironment in human prostate cancer using laser capture microdissection and reverse phase protein microarray

The cross-talk between tumor epithelium and surrounding stromal/immune microenvironment is essential to sustain tumor growth and progression and provides new opportunities for the development of targeted treatments focused on disrupting the tumor ecology. Identification of novel approaches to study these interactions is of primary importance. Using laser capture microdissection (LCM) coupled with reverse phase protein microarray (RPPA) based protein signaling activation mapping we explored the molecular interconnection between tumor epithelium and surrounding stromal microenvironment in 18 prostate cancer (PCa) specimens. Four specimen-matched cellular compartments (normal-appearing epithelium and its adjacent stroma, and malignant epithelium and its adjacent stroma) were isolated for each case. The signaling network analysis of the four compartments unraveled a number of molecular mechanisms underlying the communication between tumor cells and stroma in the context of the tumor microenvironment. In particular, differential expression of inflammatory mediators like IL-8 and IL-10 by the stroma cells appeared to modulate specific cross-talks between the tumor cells and surrounding microenvironment.

Are disseminated tumor cells in bone marrow and tumor-stroma ratio clinically applicable for patients undergoing surgical resection of primary colorectal cancer? The Leiden MRD study

Purpose

Current TNM staging does not appropriately identify high-risk colorectal cancer (CRC) patients. The aim of this study was to evaluate whether the presence of disseminated tumor cells (DTCs) in the bone marrow (BM) and the presence of stroma in the primary tumor, i.e., the tumor-stroma ratio (TSR), in patients undergoing surgical resection of primary CRC provides information relevant for disease outcome.

Methods

Patients with primary CRC (n = 125), consecutively admitted for curative resection between 2001 and 2007, were included in the study. All patients underwent BM aspiration before surgery. Detection of tumor cells was performed using immunocytochemical staining for cytokeratin (CK-ICC). The TSR was determined on diagnostic H&E stained sections of primary tumors.

Results

DTCs were detected in the BM of 23/125 patients (18 %). No association was found between BM status and overall survival (HR 0.97 (95 % CI 0.45–2.09), p = 0.93). Also, no significant difference was found in their 5-year survival rate (resp. 72 % and 68 % for BM-positive versus BM-negative patients). The TSR was found to be associated with a worse overall survival (HR 2.16, 95 % CI 1.02–4.57, p = 0.04) with 5-year survival rates of 84 % versus 62 % for stroma-low and stroma-high patients, respectively. No relation was found between the presence of DTCs and TSR.

Conclusions

Our data indicate that the presence of DTCs in the BM of CRC patients is not associated with disease outcome. The TSR was, however, found to be associated with a worse overall survival, which indicates that for CRC the tumor microenvironment plays an important role in its behavior and prognosis.

When machine vision meets histology: A comparative evaluation of model architecture for classification of histology sections

Classification of histology sections in large cohorts, in terms of distinct regions of microanatomy (e.g., stromal) and histopathology (e.g., tumor, necrosis), enables the quantification of tumor composition, and the construction of predictive models of genomics and clinical outcome. To tackle the large technical variations and biological heterogeneities, which are intrinsic in large cohorts, emerging systems utilize either prior knowledge from pathologists or unsupervised feature learning for invariant representation of the underlying properties in the data. However, to a large degree, the architecture for tissue histology classification remains unexplored and requires urgent systematical investigation. This paper is the first attempt to provide insights into three fundamental questions in tissue histology classification: I. Is unsupervised feature learning preferable to human engineered features? II. Does cellular saliency help? III. Does the sparse feature encoder contribute to recognition? We show that (a) in I, both Cellular Morphometric Feature and features from unsupervised feature learning lead to superior performance when compared to SIFT and [Color, Texture]; (b) in II, cellular saliency incorporation impairs the performance for systems built upon pixel-/patch-level features; and (c) in III, the effect of the sparse feature encoder is correlated with the robustness of features, and the performance can be consistently improved by the multi-stage extension of systems built upon both Cellular Morphmetric Feature and features from unsupervised feature learning. These insights are validated with two cohorts of Glioblastoma Multiforme (GBM) and Kidney Clear Cell Carcinoma (KIRC).

Challenging the Cancer Molecular Stratification Dogma: Intratumoral Heterogeneity Undermines Consensus Molecular Subtypes and Potential Diagnostic Value in Colorectal Cancer

PURPOSE

A number of independent gene expression profiling studies have identified transcriptional subtypes in colorectal cancer with potential diagnostic utility, culminating in publication of a colorectal cancer Consensus Molecular Subtype classification. The worst prognostic subtype has been defined by genes associated with stem-like biology. Recently, it has been shown that the majority of genes associated with this poor prognostic group are stromal derived. We investigated the potential for tumor misclassification into multiple diagnostic subgroups based on tumoral region sampled.

EXPERIMENTAL DESIGN

We performed multiregion tissue RNA extraction/transcriptomic analysis using colorectal-specific arrays on invasive front, central tumor, and lymph node regions selected from tissue samples from 25 colorectal cancer patients.

RESULTS

We identified a consensus 30-gene list, which represents the intratumoral heterogeneity within a cohort of primary colorectal cancer tumors. Using a series of online datasets, we showed that this gene list displays prognostic potential HR = 2.914 (confidence interval 0.9286-9.162) in stage II/III colorectal cancer patients, but in addition, we demonstrated that these genes are stromal derived, challenging the assumption that poor prognosis tumors with stem-like biology have undergone a widespread epithelial-mesenchymal transition. Most importantly, we showed that patients can be simultaneously classified into multiple diagnostically relevant subgroups based purely on the tumoral region analyzed.

CONCLUSIONS

Gene expression profiles derived from the nonmalignant stromal region can influence assignment of colorectal cancer transcriptional subtypes, questioning the current molecular classification dogma and highlighting the need to consider pathology sampling region and degree of stromal infiltration when employing transcription-based classifiers to underpin clinical decision making in colorectal cancer. Clin Cancer Res; 22(16); 4095-104. ©2016 AACRSee related commentary by Morris and Kopetz, p. 3989.

Fibroblasts, an inconspicuous but essential player in colon cancer development and progression

Tumor microenvironments have a crucial role in cancer initiation and progression, and share many molecular and pathological features with wound healing process. Unless treated, tumors, however, do not heal in contrast to wounds that heal within a limited time framework. Wounds heal in coordination of a myriad of types of cells, particularly endothelial cells, leukocytes, and fibroblasts. Similar sets of cells also contribute to cancer initiation and progression, and as a consequence, anti-cancer treatment strategies have been proposed and tested by targeting endothelial cells and/or leukocytes. Compared with endothelial cells and leukocytes, less attention has been paid to the roles of cancer-associated fibroblasts (CAFs), fibroblasts present in tumor tissues, because their heterogeneity hinders the elucidation on them at cellular and molecular levels. Here, we will discuss the origin of CAFs and their crucial roles in cancer initiation and progression, and the possibility to develop a novel type of anti-cancer treatment by manipulating the migration and functions of CAFs.

Multi-class texture analysis in colorectal cancer histology

Automatic recognition of different tissue types in histological images is an essential part in the digital pathology toolbox. Texture analysis is commonly used to address this problem; mainly in the context of estimating the tumour/stroma ratio on histological samples. However, although histological images typically contain more than two tissue types, only few studies have addressed the multi-class problem. For colorectal cancer, one of the most prevalent tumour types, there are in fact no published results on multiclass texture separation. In this paper we present a new dataset of 5,000 histological images of human colorectal cancer including eight different types of tissue. We used this set to assess the classification performance of a wide range of texture descriptors and classifiers. As a result, we found an optimal classification strategy that markedly outperformed traditional methods, improving the state of the art for tumour-stroma separation from 96.9% to 98.6% accuracy and setting a new standard for multiclass tissue separation (87.4% accuracy for eight classes). We make our dataset of histological images publicly available under a Creative Commons license and encourage other researchers to use it as a benchmark for their studies.

Clinical Trial of Oral Nelfinavir before and during Radiation Therapy for Advanced Rectal Cancer

PURPOSE

Nelfinavir, a PI3K pathway inhibitor, is a radiosensitizer that increases tumor blood flow in preclinical models. We conducted an early-phase study to demonstrate the safety of nelfinavir combined with hypofractionated radiotherapy (RT) and to develop biomarkers of tumor perfusion and radiosensitization for this combinatorial approach.

EXPERIMENTAL DESIGN

Ten patients with T3-4 N0-2 M1 rectal cancer received 7 days of oral nelfinavir (1,250 mg b.i.d.) and a further 7 days of nelfinavir during pelvic RT (25 Gy/5 fractions/7 days). Perfusion CT (p-CT) and DCE-MRI scans were performed pretreatment, after 7 days of nelfinavir and prior to the last fraction of RT. Biopsies taken pretreatment and 7 days after the last fraction of RT were analyzed for tumor cell density (TCD).

RESULTS

There were 3 drug-related grade 3 adverse events: diarrhea, rash, and lymphopenia. On DCE-MRI, there was a mean 42% increase in medianKtrans, and a corresponding median 30% increase in mean blood flow on p-CT during RT in combination with nelfinavir. Median TCD decreased from 24.3% at baseline to 9.2% in biopsies taken 7 days after RT (P= 0.01). Overall, 5 of 9 evaluable patients exhibited good tumor regression on MRI assessed by tumor regression grade (mrTRG).

CONCLUSIONS

This is the first study to evaluate nelfinavir in combination with RT without concurrent chemotherapy. It has shown that nelfinavir-RT is well tolerated and is associated with increased blood flow to rectal tumors. The efficacy of nelfinavir-RT versus RT alone merits clinical evaluation, including measurement of tumor blood flow.

Comparison of the prognostic value of measures of the tumor inflammatory cell infiltrate and tumor-associated stroma in patients with primary operable colorectal cancer

The aim of the present study was to compare the clinical utility of two measures of the inflammatory cell infiltrate - a H&E-based assessment of the generalized inflammatory cell infiltrate (the Klintrup-Mäkinen (KM) grade), and an immunohistochemistry-based assessment of combined CD3⁺ and CD8⁺ T-cell density (the "Immunoscore"), in conjunction with assessment of the tumor stroma percentage (TSP) in patients undergoing resection of stage I-III colorectal cancer (CRC). Two hundred and forty-six patients were identified from a prospectively maintained database of CRC resections in a single surgical unit. Assessment of KM grade and TSP was performed using full H&E sections. CD3⁺ and CD8⁺ T-cell density was assessed on full sections and the Immunoscore calculated. KM grade and Immunoscore were strongly associated (p < 0.001). KM grade stratified cancer-specific survival (CSS) from 88% to 66% (p = 0.002) and Immunoscore from 93% to 61% (p < 0.001). Immunoscore further stratified survival of patients independent of KM grade from 94% (high KM, Im4) to 60% (low KM, Im0/1). Furthermore, TSP stratified survival of patients with a weak inflammatory cell infiltrate (low KM: from 75% to 47%; Im0/1: from 71% to 38%, both p < 0.001) but not those with a strong inflammatory infiltrate. On multivariate analysis, only Immunoscore (HR 0.44, p < 0.001) and TSP (HR 2.04, p < 0.001) were independently associated with CSS. These results suggest that the prognostic value of an immunohistochemistry-based assessment of the inflammatory cell infiltrate is superior to H&E-based assessment in patients undergoing resection of stage I-III CRC. Furthermore, assessment of the tumor-associated stroma, using TSP, further improves prediction of outcome.

Combining standardized uptake value of FDG-PET and apparent diffusion coefficient of DW-MRI improves risk stratification in head and neck squamous cell carcinoma

OBJECTIVES

To assess the independent prognostic value of standardized uptake value (SUV) and apparent diffusion coefficient (ADC), separately and combined, in order to evaluate if the combination of these two variables allows further prognostic stratification of patients with head and neck squamous cell carcinomas (HNSCC).

METHODS

Pretreatment SUV and ADC were calculated in 57 patients with HNSCC. Mean follow-up was 21.3 months. Semiquantitative analysis of primary tumours was performed using SUV_maxT/B, ADC_mean, ADC_min and ADC_max. The prognostic value of SUV_maxT/B, ADC_mean, ADC_min and ADC_max in predicting disease-free survival (DFS) was evaluated with log-rank test and Cox regression models.

RESULTS

Patients with SUV_maxT/B ≥5.75 had an overall worse prognosis (p = 0.003). After adjusting for lymph node status and diameter, SUV_maxT/B and ADC_min were both significant predictors of DFS with hazard ratio (HR) = 10.37 (95 % CI 1.22-87.95) and 3.26 (95 % CI 1.20-8.85) for SUV_maxT/B ≥5.75 and ADC_min ≥0.58 × 10^-3 mm²/s, respectively. When the analysis was restricted to subjects with SUV_maxT/B ≥5.75, high ADC_min significantly predicted a worse prognosis, with adjusted HR = 3.11 (95 % CI 1.13-8.55).

CONCLUSIONS

The combination of SUV_maxT/B and ADC_min improves the prognostic role of the two separate parameters; patients with high SUV_maxT/B and high ADC_min are associated with a poor prognosis.

KEY POINTS

• High SUV _maxT/B is a poor prognostic factor in HNSCC • High ADC _min is a poor prognostic factor in HNSCC • In patients with high SUV _maxT/B , high ADC _min identified those with worse prognosis.

Digital Sorting of Pure Cell Populations Enables Unambiguous Genetic Analysis of Heterogeneous Formalin-Fixed Paraffin-Embedded Tumors by Next Generation Sequencing

Precision medicine in oncology requires an accurate characterization of a tumor molecular profile for patient stratification. Though targeted deep sequencing is an effective tool to detect the presence of somatic sequence variants, a significant number of patient specimens do not meet the requirements needed for routine clinical application. Analysis is hindered by contamination of normal cells and inherent tumor heterogeneity, compounded with challenges of dealing with minute amounts of tissue and DNA damages common in formalin-fixed paraffin-embedded (FFPE) specimens. Here we present an innovative workflow using DEPArray™ system, a microchip-based digital sorter to achieve 100%-pure, homogenous subpopulations of cells from FFPE samples. Cells are distinguished by fluorescently labeled antibodies and DNA content. The ability to address tumor heterogeneity enables unambiguous determination of true-positive sequence variants, loss-of-heterozygosity as well as copy number variants. The proposed strategy overcomes the inherent trade-offs made between sensitivity and specificity in detecting genetic variants from a mixed population, thus rescuing for analysis even the smaller clinical samples with low tumor cellularity.

Mismatch repair status in patients with primary operable colorectal cancer: associations with the local and systemic tumour environment

Background:

Mismatch repair-deficient (dMMR) colorectal cancer (CRC) is associated with a conspicuous local immune infiltrate; however, its relationship with systemic inflammatory responses remains to be determined. The present study aims to examine the relationships and prognostic value of assessment of the local and systemic environment in the context of MMR status in patients with CRC.

Methods:

The relationship between MMR status, determined using immunohistochemistry, and the local inflammatory cell infiltrate, differential white cell count, neutrophil : platelet score (NPS), neutrophil : lymphocyte ratio and modified Glasgow Prognostic Score (mGPS), and cancer-specific survival was examined in 228 patients undergoing resection of stage I–III CRC.

Results:

Thirty-five patients (15%) had dMMR CRC. Mismatch repair deficiency was associated with a higher density of CD3⁺, CD8⁺ and CD45R0⁺ T lymphocytes within the cancer cell nests and an elevated mGPS (mGPS2: 23% vs 9%, P=0.007) and NPS (NPS2: 19% vs 3%, P=0.001). CD3⁺ density (P<0.001), mGPS (P=0.01) and NPS (P=0.042) were associated with survival independent of MMR status (P=0.367) and stratified 5-year survival of patients with MMR-competent CRC from 94% to 67%, 83% to 46% and 78% to 60% respectively.

Conclusions:

Mismatch repair deficiency was associated with local and systemic environments, and in comparison with their assessment, dMMR had relatively poor prognostic value in patients with primary operable CRC. In addition to MMR status, local and systemic inflammatory responses should be assessed in these patients.

A 5-gene classifier from the carcinoma-associated fibroblast transcriptomic profile and clinical outcome in colorectal cancer

Based on 108 differentially expressed genes between carcinoma-associated fibroblasts (CAFs) and paired normal colonic fibroblasts we recently reported, a 5-gene classifier for relapse prediction in Stage II/III colorectal cancer (CRC ) was developed. Its predictive value was validated in datasets GSE17538, GSE33113 and GSE14095. An additional validation was performed in a metacohort (n=317) and 142 CRC patients by means of RT-PCR. The 5-gene classifier was significantly associated with increased relapse risk and death from CRC across all validation series of Stage II/III patients used. Multivariate Cox regression analyses confirmed the independent prognostic value of the stromal classifier (HR=2.67; P=0.002). Post-test probabilities provided evidence of the suitability of the 5-gene classifier in clinical practice, identifying a subgroup of Stage-II patients who were at high risk of relapse. Moreover, the a priory worst prognosis mesenchymal subtype of tumours can be stratified according to the physiological status of their carcinoma-associated fibroblasts. In conclusion the CAFs-derived 5-gene classifier provides more accurate information about outcome than conventional clinicopathological criteria and it could be useful to take clinical decisions, especially in Stage II. Additionally, the classifier put into relevance the CAF's intratumoral heterogeneity and might contribute to find relevant targets for depleting adequate CAFS subtypes.

The prognostic significance of tumour-stroma ratio in endometrial carcinoma

Background

High tumour stromal content has been found to predict adverse clinical outcome in a range of epithelial tumours. The aim of this study was to assess the prognostic significance of tumour-stroma ratio (TSR) in endometrial adenocarcinomas and investigate its relationship with other clinicopathological parameters.

Methods

Clinicopathological and 5-year follow-up data were obtained for a retrospective series of endometrial adenocarcinoma patients (n = 400). TSR was measured using a morphometric approach (point counting) on digitised histologic hysterectomy specimens. Inter-observer agreement was determined using Cohen’s Kappa statistic. TSR cut-offs were optimised using log-rank functions and prognostic significance of TSR on overall survival (OS) and disease-free survival (DFS) were determined using Cox Proportional Hazards regression analysis and Kaplan-Meier curves generated. Associations of TSR with other clinicopathological parameters were determined using non-parametric tests followed by Holm-Bonferroni correction for multiple comparisons.

Results

TSR as a continuous variable associated with worse OS (P = 0.034) in univariable Cox-regression analysis. Using the optimal cut-off TSR value of 1.3, TSR-high (i.e. low stroma) was associated with worse OS (HR = 2.51; 95 % CI = 1.22–5.12; P = 0.021) and DFS (HR = 2.19; 95 % CI = 1.15–4.17; P = 0.017) in univariable analysis. However, TSR did not have independent prognostic significance in multivariable analysis, when adjusted for known prognostic variables. A highly significant association was found between TSR and tumour grade (P < 0.001) and lymphovascular space invasion (P < 0.001), both of which had independent prognostic significance in this study population.

Conclusions

Low tumour stromal content associates with both poor outcome and with other adverse prognostic indicators in endometrial cancer, although it is not independently prognostic. These findings contrast with studies on many - although not all - cancers and suggest that the biology of tumour-stroma interactions may differ amongst cancer types.