The tumor microenvironment has a critical role in regulating cancer cell behavior. Tumors with high stromal content are associated with poor patient outcome. The tumor-stroma ratio (TSR) identifies ...colorectal cancers (CRC) with poor patient prognosis based on hematoxylin & eosin stained sections. The desmoplastic reaction consists to a great extent of cancer-associated fibroblasts (CAFs) of which different subtypes are known. The aim of this study is to investigate and quantify CAFs present in the tumor stroma of CRC stratified by the TSR to possibly add prognostic significance to the TSR.
The expression of established CAF markers was compared between stroma-low and stroma-high tumors using transcriptomic data of 71 stage I - III CRC. Based on literature, fibroblast and stromal markers were selected to perform multiplex immunofluorescent staining on formalin fixed, paraffin-embedded tumor sections of patients diagnosed with stage III colon cancer. Antibodies against the following markers were used: αSMA, PDGFR -β, FAP, FSP1 and the stromal markers CD45 and CD31 as reference. The markers were subsequently quantified in the stroma using the Vectra imaging microscope.
The transcriptomic data showed that all CAF markers except one were higher expressed in stroma-high compared to stroma-low tumors. Histologically, stroma-high tumors showed a decreased number of FSP1
/CD45
cells and a trend of an increased expression of FAP compared to stroma-low tumors. FAP was higher expressed at the invasive part compared to the tumor center in both stroma-high and stroma-low tumors.
The increased expression of FAP at the invasive part and in stroma-high tumors might contribute to the invasive behavior of cancer cells. Future functional experiments should investigate the contribution of FAP to cancer cell invasion. Combining the quantity of the stroma as defined by the TSR with the activity level of CAFs using the expression of FAP may result in an expanded stroma-based tool for patient stratification.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The tumor–stroma ratio (TSR) has previously been found to be a strong prognostic parameter in primary breast cancer tumors. Since the presence of tumor cells in lymph nodes is important for clinical ...decision making, the influence of TSR in the primary breast tumor combined with the TSR in tumor‐positive lymph nodes on prognosis was evaluated. Women with invasive breast cancer without distant metastasis who underwent an axillary lymph node dissection between 1985 and 1994 at the Leiden University Medical Center were retrospectively analyzed. TSR assessment was performed on hematoxylin and eosin stained tissue slides. In total, 87 (45.5%) primary tumors were scored as stroma‐low and 104 (54.5%) as stroma‐high. Patients with a high stromal percentage in the primary tumors had a statistically significant worse relapse free period (RFP) compared to stroma‐low tumors (HR 1.97, 95% CI 1.37–2.82, p < 0.001). A total number of 915 lymph nodes were assessed for TSR. In 101 (52.9%) patients, heterogeneity was observed between stroma percentage category in primary tumor and lymph nodes. The combination of TSR of the primary tumor combined with TSR of tumor‐positive lymph nodes strengthened each other as independent prognostic parameter for RFP (p = 0.019). Patients with primary tumor stroma‐low/lymph nodes stroma‐low tumors showed strongly improved RFP rates compared to patients with primary tumor stroma‐high/lymph node stroma‐high tumors with 10‐year percentages of 58 versus 8%, respectively. Assessing the TSR on tumor‐positive lymph nodes can provide additional prognostic information. Stromal activation strongly differs between primary tumors and lymph node metastasis.
What's new?
Measuring the amount of stroma in tumor‐ positive lymph nodes, not just only in the primary tumor, can better predict breast cancer relapse. In recent years, researchers have increasingly looked to the tumor microenvironment for prognostic clues. Here, the authors compared the prognostic value of the TSR in primary breast tumors alone with TSR from both primary tumor and tumor‐positive lymph nodes. Risk of relapse for patients with high amount of stroma at the primary tumor was 75%, while a combination of stroma‐high primary tumor and stroma‐high lymph nodes correlated with 92% relapse rate after 10 years of follow‐up.
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.
Stroma tissue surrounding cancer cells plays an important role in tumor development and behavior. In colorectal cancer, it has been found that the amount of stroma within the primary tumor is of ...prognostic value. We therefore have evaluated the prognostic value of this tumor–stroma ratio for breast cancer. A cohort of 574 early breast cancer patients, primarily treated with surgery between 1985 and 1994 was analyzed for the tumor–stroma ratio. The percentage of stroma was visually estimated on Haematoxylin-Eosin (H&E) stained histological sections. Patients with more than 50% intra-tumor stroma were quantified as stroma rich and patients with less than 50% as stroma poor. For the total group of patients, stroma-rich tumors had a shorter relapse-free period (RFP) (
P
= 0.001) and overall survival (OS) (
P
= 0.025) compared to stroma-poor tumors. Tumor–stroma ratio was an independent prognostic parameter for the total group of patients (
P
< 0.001) and also in stratified analysis based on systemic treatment. Importantly, in the triple-negative cancer subpopulation, patients with stroma-rich tumors had a 2.92 times higher risk of relapse (
P
= 0.006) compared to those with stroma-poor tumors, independently of other clinico-pathological parameters. Five-year RFP-rates for triple-negative cancer patients with stroma-rich compared to stroma-poor tumors were 56 and 81%, respectively. Tumor–stroma ratio has proven to be an independent prognostic factor for RFP in breast cancer patients and especially in the triple-negative cancer subpopulation. Tumor–stroma ratio could be easily implemented in routine daily pathology diagnostics, as it is simple to determine, reproducible, and performed in quick time.
Colorectal cancer (CRC) is a heterogeneous disease in which unique subtypes are characterized by distinct genetic and epigenetic alterations. Here we performed comprehensive genome-scale DNA ...methylation profiling of 125 colorectal tumors and 29 adjacent normal tissues. We identified four DNA methylation-based subgroups of CRC using model-based cluster analyses. Each subtype shows characteristic genetic and clinical features, indicating that they represent biologically distinct subgroups. A CIMP-high (CIMP-H) subgroup, which exhibits an exceptionally high frequency of cancer-specific DNA hypermethylation, is strongly associated with MLH1 DNA hypermethylation and the BRAF(V600E) mutation. A CIMP-low (CIMP-L) subgroup is enriched for KRAS mutations and characterized by DNA hypermethylation of a subset of CIMP-H-associated markers rather than a unique group of CpG islands. Non-CIMP tumors are separated into two distinct clusters. One non-CIMP subgroup is distinguished by a significantly higher frequency of TP53 mutations and frequent occurrence in the distal colon, while the tumors that belong to the fourth group exhibit a low frequency of both cancer-specific DNA hypermethylation and gene mutations and are significantly enriched for rectal tumors. Furthermore, we identified 112 genes that were down-regulated more than twofold in CIMP-H tumors together with promoter DNA hypermethylation. These represent ∼7% of genes that acquired promoter DNA methylation in CIMP-H tumors. Intriguingly, 48/112 genes were also transcriptionally down-regulated in non-CIMP subgroups, but this was not attributable to promoter DNA hypermethylation. Together, we identified four distinct DNA methylation subgroups of CRC and provided novel insight regarding the role of CIMP-specific DNA hypermethylation in gene silencing.
High-throughput mass spectrometry (MS) glycomics is an emerging field driven by technological advancements including sample preparation and data processing. Previously, we reported an automated ...protocol for the analysis of N-glycans released from plasma proteins that included sialic acid derivatization with linkage-specificity, namely, ethylation of α2,6-linked sialic acid residues and lactone formation of α2,3-linked sialic acids. In the current study, each step in this protocol was further optimized. Method improvements included minimizing the extent of side-reaction during derivatization, an adjusted glycan purification strategy and mass analysis of the released N-glycans by ultrahigh resolution matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance MS. The latter resolved peak overlap and simplified spectral alignment due to high mass measurement precision. Moreover, this resulted in more confident glycan assignments and improved signal-to-noise for low-abundant species. The performance of the protocol renders high-throughput applications feasible in the exciting field of clinical glycomics.
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.
Extensive changes in DNA methylation are common in cancer and may contribute to oncogenesis through transcriptional silencing of tumor-suppressor genes. Genome-scale studies have yielded important ...insights into these changes but have focused on CpG islands or gene promoters. We used whole-genome bisulfite sequencing (bisulfite-seq) to comprehensively profile a primary human colorectal tumor and adjacent normal colon tissue at single-basepair resolution. Regions of focal hypermethylation in the tumor were located primarily at CpG islands and were concentrated within regions of long-range (>100 kb) hypomethylation. These hypomethylated domains covered nearly half of the genome and coincided with late replication and attachment to the nuclear lamina in human cell lines. We confirmed the confluence of hypermethylation and hypomethylation within these domains in 25 diverse colorectal tumors and matched adjacent tissue. We propose that widespread DNA methylation changes in cancer are linked to silencing programs orchestrated by the three-dimensional organization of chromatin within the nucleus.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Breast cancer is the most prevalent cancer in women. Early detection of this disease improves survival and therefore population screenings, based on mammography, are performed. However, the ...sensitivity of this screening modality is not optimal and new screening methods, such as blood tests, are being explored. Most of the analyses that aim for early detection focus on proteins in the bloodstream. In this study, the biomarker potential of total serum
N
-glycosylation analysis was explored with regard to detection of breast cancer. In an age-matched case-control setup serum protein
N
-glycan profiles from 145 breast cancer patients were compared to those from 171 healthy individuals.
N
-glycans were enzymatically released, chemically derivatized to preserve linkage-specificity of sialic acids and characterized by high resolution mass spectrometry. Logistic regression analysis was used to evaluate associations of specific
N
-glycan structures as well as
N
-glycosylation traits with breast cancer. In a case-control comparison three associations were found, namely a lower level of a two triantennary glycans and a higher level of one tetraantennary glycan in cancer patients. Of note, various other
N
-glycomic signatures that had previously been reported were not replicated in the current cohort. It was further evaluated whether the lack of replication of breast cancer
N
-glycomic signatures could be partly explained by the heterogenous character of the disease since the studies performed so far were based on cohorts that included diverging subtypes in different numbers. It was found that serum
N
-glycan profiles differed for the various cancer subtypes that were analyzed in this study.
Conflicting conclusions have been published regarding breast cancer survival of BRCA1/2 mutation carriers. Here we provide an evidence-based systematic literature review.
Eligible publications were ...observational studies assessing the survival of breast cancer patients carrying a BRCA1/2 mutation compared to non-carriers or the general breast cancer population. We performed meta-analyses and best-evidence syntheses for survival outcomes taking into account study quality assessed by selection bias, misclassification bias and confounding.
Sixty-six relevant studies were identified. Moderate evidence for a worse unadjusted recurrence-free survival for BRCA1 mutation carriers was found. For BRCA1 and BRCA2 there was a tendency towards a worse breast cancer-specific and overall survival, however, results were heterogeneous and the evidence was judged to be indecisive. Surprisingly, only 8 studies considered adjuvant treatment as a confounder or effect modifier while only two studies took prophylactic surgery into account. Adjustment for tumour characteristics tended to shift the observed risk estimates towards a relatively more favourable survival.
In contrast to currently held beliefs of some oncologists, current evidence does not support worse breast cancer survival of BRCA1/2 mutation carriers in the adjuvant setting; differences if any are likely to be small. More well-designed studies are awaited.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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