Tissue microarray technology: validation in colorectal carcinoma and analysis of p53, hMLH1, and hMSH2 immunohistochemical expression

Virtual Tissue Microarrays for Validating Digital Biomarker Analysis in Colorectal Carcinoma

Tissue microarrays (TMAs) are used for high-throughput biomarker discovery and validation. Although TMAs have numerous advantages, they may not always be representative of the tissue heterogeneity present in whole tissue sections (WTS) leading to inadequate biomarker quantification. In this pilot study, we studied biomarker expression in 50 randomly selected colorectal cancers and 36 microsatellite unstable cases with or without BRAF variants. We used virtual TMAs to determine the minimum number of tissue cores needed to quantify biomarkers with the same precision as when using WTS. Paraffin sections were immunohistochemically stained for markers of T cells, B cells, cancer-associated fibroblasts, and macrophages. Digitized WTS were divided into tumor center (TC) and invasive margin regions. The minimum number of virtual TMA cores in each region was determined by Bland-Altman plots with 95% limits of agreement. Bland-Altman plots showed substantial disagreement between TMAs and WTS, being highest for 3 cores and decreasing with increasing core numbers. However, even when using 8 cores, the limits of agreement between TMA and WTS were wide, indicating a high degree of measuring uncertainty using TMAs. When using 3 or 4 cores, TMAs underestimated the expression of all the biomarkers in the TC; similarly, levels of macrophage markers in the TC, and levels of B cells in both the TC and the invasive margin remained considerably underestimated, even when using the maximum number of cores possible. However, 3 cores were sufficient to adequately classify biomarkers into categoric low and high expression groups. Microsatellite unstable tumors were characterized by high heterogeneity, which was further increased in the presence of BRAF variant(s). The virtual TMA technique is a useful method to establish the minimum number of cores to be included when constructing tumor TMAs for biomarker analysis. Our results emphasize the importance of TMA validation for a specific biomarker prior to conducting larger clinical studies.

Increased nuclear expression of DNA damage inducible transcript 4 can serve as a potential prognostic biomarker in patients with gliomas: a study based on data mining and experimental tools

INTRODUCTION

DNA damage-inducible transcript 4 (DDIT4), induced under cellular stress conditions, has been implicated in malignancies due to its abnormal expression patterns.

MATERIALS AND METHODS

The expression of DDIT4 at the mRNA level and its potential role as a prognostic biomarker in gliomas were analyzed using the GEPIA tool. To validate these findings, DDIT4 protein expression levels and their prognostic significance were examined in tissue microarrays from glioma patients using immunohistochemistry in clinical samples.

RESULTS

Bioinformatics analysis revealed that DDIT4 overexpression in glioma tumors and its high mRNA expression levels are associated with poor outcomes, likely through mTOR signaling. At the protein level, positive nuclear DDIT4 expression was linked to higher histological grades and temozolomide treatment. Kaplan-Meier survival analysis demonstrated that positive nuclear DDIT4 expression is a significant predictor of poor disease-specific survival (DSS) and recurrence-free survival (RFS). Additionally, nuclear DDIT4 expression was identified as an independent prognostic factor for DSS.

CONCLUSION

Our findings suggest that nuclear DDIT4 expression may serve as a potential prognostic biomarker and therapeutic target in glioma patients. However, further studies with larger sample sizes and long-term follow-ups are needed to validate these observations and confirm their clinical relevance.

Cytoplasmic SALL4-A isoform expression as a diagnostic marker of less aggressive tumor behavior in gastric cancer

BACKGROUND

Gastric cancer (GC) poses significant challenges globally, ranking fifth in incidence and fourth in cancer-related mortality. SALL4, a stem cell transcription factor with multiple isoforms, includes SALL4-A as its full-length form. This study aims to evaluate the diagnostic potential of SALL4-A isoform expression in GC and its clinical significance.

METHOD

Immunohistochemical (IHC) analysis was conducted on Tissue Micro Array (TMA) slides from 167 GC patients. Clinicopathological parameters were correlated with SALL4-A expression, and survival analysis was performed. Diagnostic performance was assessed using metrics such as sensitivity, specificity, and area under the curve (AUC).

RESULTS

SALL4-A exhibited distinct cytoplasmic expression in GC, correlating with lower histological grade (p = 0.003) and TNM stage (p = 0.003), particularly in the intestinal subtype. Diagnostic evaluation showed an AUC of 0.803 for cytoplasmic expression, demonstrating high diagnostic potential. However, SALL4-A expression did not show significant prognostic value.

CONCLUSION

Cytoplasmic SALL4-A expression in GC is associated with less aggressive tumor phenotypes and shows promise as a diagnostic marker. Further research is warranted to elucidate its mechanistic role and potential integration into clinical practice.

Clinical significance of Talin-1 and HER-2 status in different types of gastric carcinoma

BACKGROUND

Talin-1 (TLN1) is crucial in cell migration, metastasis, and cancer development. This study evaluated Talin-1 expression and its clinical significance in gastric cancer (GC), along with human epidermal growth factor receptor-2 (HER-2) expression and its correlation with Talin-1.

METHODS

Bioinformatics analysis assessed the potential prognostic value of Talin-1 and HER-2 in GC patients. The study included 223 GC patients (Signet Ring Cells and Intestinal subtypes) and 29 non-malignant tissue samples. Immunohistochemistry (IHC) on tissue microarray slides evaluated Talin-1 and HER-2 expression and clinical significance. Receiver operating characteristic (ROC) curves assessed their diagnostic value.

RESULTS

Bioinformatics identified Talin-1 as a potential prognostic factor and HER-2 as an oncogene in GC. Talin-1 and HER-2 expression increased in SRC-type GC samples compared to non-malignant tissues. High cytoplasmic Talin-1 expression inversely correlated with tumor expansion and invasion in SRC-type GC. Increased HER-2 expression positively correlated with metastasis. ROC curves showed significant diagnostic values for both proteins.

CONCLUSIONS

Higher cytoplasmic Talin-1 expression is associated with less invasive tumor behavior, while increased membranous HER-2 expression is associated with metastasis in SRC-type GC. These findings suggest potential use in assessing diagnosis and screening high-risk cancer patients, particularly those with SRC-type GC.

Nuclear Expression of Dynamin 2 Is Associated With Tumor Aggressiveness in Bladder Cancer Patients: A Bioinformatics and Experimental Approach

BACKGROUND

Dynamin 2 (DNM2) is aberrantly expressed in different malignancies and exerts a function in tumor progression.

AIMS

This study, for the first time, aimed to evaluate the clinical and prognostic value of DNM2 in the pathophysiology of bladder cancer using bioinformatics analysis and experimental evaluation.

METHODS AND RESULTS

We analyzed gene expression of DNM2 in bladder tumor by GEPIA2 and GENT2 platforms. Cluster subnetworks were recognized from the protein-protein interaction (PPI) network using the MCODE plugin to screen the key genes. Subsequently, the pathway enrichment analysis was evaluated. Then, the immunohistochemical examination was conducted on 209 paraffin-embedded bladder cancer samples to determine the expression pattern and clinical importance of DNM2. Our data mining findings demonstrated dysregulation of DNM2 gene expression in bladder cancer. The results of pathway and PPI network analyses indicated that DNM2 might be involved in the development of bladder cancer by influencing various signaling pathways. Our IHC results represented remarkably higher DNM2 expression in bladder tumor samples compared to normal tissue samples adjacent to tumor. A statistically significant association was identified between DNM2 expression in the nucleus and higher histological grade (p = 0.026), advanced pT stage (p = 0.016), muscular invasion (p = 0.007), tumor recurrence (p = 0.030), and distant metastasis (p < 0.001). Moreover, the nuclear DNM2 expression was observed to have prognostic significance for disease-specific survival (DSS) using a log-rank test (p = 0.028).

CONCLUSION

These findings suggest that nuclear DNM2 expression could be a putative indicator of bladder tumor progression owing to its association with elevated cancer aggressiveness.

Higher Expression of Talin-1 is Associated With Less Aggressive Tumor Behavior in Pancreatic Cancer

Talin-1 is one of the major scaffold proteins in focal adhesions playing a vital role in cell migration, metastasis, and cancer progression. Although studies regarding the importance of Talin-1 in cancer have rapidly developed, its prognostic and diagnostic value still remain unsatisfying in pancreatic cancer (PC). Therefore, the present study aims to investigate the expression, clinical significance, as well as the prognostic and diagnostic value of Talin-1 in different types of PC. Bioinformatic analysis was applied to determine the clinical importance and biological role of Talin-1 expression in PC tumors and the normal adjacent samples. The expression patterns, clinical significance, prognosis, and diagnosis value of Talin-1 were evaluated in tissue microarrays (TMAs) of 190 PC samples including 170 pancreatic ductal adenocarcinoma (PDAC), and 20 pancreatic neuroendocrine tumors (PNET), along with 24 adjacent normal tissues using immunohistochemistry (IHC). The results indicated that the expression of Talin-1 was upregulated in tumor cells compared with adjacent normal tissues. A statistically significant association was observed between the higher cytoplasmic expression of Talin-1 and lower histologic grade ( P <0.001) in PDAC samples. Further, our findings indicated an inverse significant correlation between cytoplasmic expression of Talin-1 and recurrence ( P =0.014) in PNET samples. No significant association was observed between the cytoplasmic expression of Talin-1 and survival outcomes as well as diagnostic accuracy. In conclusion, our observations demonstrated that a higher cytoplasmic level of Talin-1 protein was significantly associated with less aggressive tumor behaviors in PC samples. Nevertheless, further investigations are required to explore the prognostic plus diagnostic value, and mechanism of action of Talin-1 in pancreatic cancer.

Higher expression of SALL4-A isoform is correlated with worse outcomes and progression of the disease in subtype of testicular germ cell tumours

BACKGROUND

The transcription factor SALL4 is associated with embryonic pluripotency and has proposed as a novel immunohistochemistry (IHC) marker for diagnosing germ cell tumours. SALL4 comprises three isoforms, and SALL4-A being the full-length isoform. Studying its isoforms could revolutionize testicular cancer prognosis and subtype differentiation.

METHODS

The expression and clinical significance of isoform 'A' of SALL4 was evaluated in 124 testicular germ cell tumours (TGCTs) subtypes, adjacent 67 normal tissues and 22 benign tumours, using immunohistochemistry on tissue microarrays (TMA).

RESULTS

A statistically significant higher expression of nuclear and cytoplasmic SALL4-A was detected in TGCTs histological subtypes and benign tumours compared to the normal tissues. Seminoma and yolk sac tumours had the highest nuclear and cytoplasmic expression of SALL4-A. A significant correlation was detected between the higher nuclear expression of SALL4-A and increased pT stages (P = 0.026) in seminomas. Whereas in embryonal carcinomas, cytoplasmic expression of SALL4-A was associated with the tumour recurrence (P = 0.04) and invasion of the epididymis (P = 0.011).

CONCLUSIONS

SALL4-A isoform expression in the cytoplasm and nucleus of TGCTs may be associated with histological differentiation. In the seminoma subtype of TGCTs, higher expression of SALL4-A may be used as a predictive indicator of poorer outcomes and prognosis.

Multiplexed analysis of macrophage polarisation in pulmonary metastases of microsatellite stable colorectal cancer

Tumour-associated macrophages (TAMs) express a continuum of phenotypes ranging from an anti-tumoural M1-like phenotype to a pro-tumoural M2-like phenotype. During cancer progression, TAMs may shift to a more M2-like polarisation state, but the role of TAMs in CRC metastases is unclear. We conducted a comprehensive spatial and prognostic analysis of TAMs in CRC pulmonary metastases and corresponding primary tumours using multiplexed immunohistochemistry and machine learning-based image analysis. We obtained data from 106 resected pulmonary metastases and 74 corresponding primary tumours. TAMs in the resected pulmonary metastases were located closer to the cancer cells and presented a more M2-like polarised state in comparison to the primary tumours. Higher stromal M2-like macrophage densities in the invasive margin of pulmonary metastases were associated with worse 5-year overall survival (HR 3.19, 95% CI 1.35-7.55, p = 0.008). The results of this study highlight the value of multiplexed analysis of macrophage polarisation in cancer metastases and might have clinical implications in future cancer therapy.

Nuclear overexpression of DNA damage-inducible transcript 4 (DDIT4) is associated with aggressive tumor behavior in patients with pancreatic tumors

DNA damage-inducible transcript 4 (DDIT4) is induced in various cellular stress conditions. Several studies showed that the dysregulation of DDIT4 is involved in different malignancies with paradoxical expressions and roles. Therefore, this study investigated the clinical significance, prognostic, and diagnostic value of DDIT4 in different types of pancreatic tumors (PT). The expression of DDIT4 and long non-coding RNA (TPTEP1) in mRNA level was examined in 27 fresh PT samples using Real-time quantitative PCR (RT-qPCR). Moreover, 200 formalin-fixed paraffin-embedded PT tissues, as well as 27 adjacent normal tissues, were collected to evaluate the clinical significance, prognostic, and diagnosis value of DDIT4 expression by immunohistochemistry (IHC) on tissue microarrays (TMA) slides. The results of RT-qPCR showed that the expression of DDIT4 in tumor samples was higher than in normal samples which was associated with high tumor grade (P = 0.015) and lymphovascular invasion (P = 0.048). Similar to this, IHC findings for nucleus, cytoplasm, and membrane localization showed higher expression of DDIT4 protein in PT samples rather than in nearby normal tissues. A statistically significant association was detected between a high level of nuclear expression of DDIT4 protein, and lymphovascular invasion (P = 0.025), as well as advanced TNM stage (P = 0.034) pancreatic ductal adenocarcinoma (PDAC) and in pancreatic neuroendocrine tumor (PNET), respectively. In contrast, a low level of membranous expression of DDIT4 protein showed a significant association with advanced histological grade (P = 0.011), margin involvement (P = 0.007), perineural invasion (P = 0.023), as well as lymphovascular invasion (P = 0.005) in PDAC. No significant association was found between survival outcomes and expression of DDIT4 in both types. It was found that DDIT4 has rational accuracy and high sensitivity as a diagnostic marker. Our results revealed a paradoxical role of DDIT4 expression protein based on the site of nuclear and membranous expression. The findings of this research indicated that there is a correlation between elevated nuclear expression of DDIT4 and the advancement and progression of disease in patients with PT. Conversely, high membranous expression of DDIT4 was associated with less aggressive tumor behavior in patients with PDAC. However, further studies into the prognostic value and biological function of DDIT4 are needed in future studies.

Loss of SATB2 expression correlates with cytokeratin 7 and PD-L1 tumor cell positivity and aggressiveness in colorectal cancer

Colorectal carcinoma (CRC) is a disease that causes significant morbidity and mortality worldwide. To improve treatment, new biomarkers are needed to allow better patient risk stratification in terms of prognosis. This study aimed to clarify the prognostic significance of colonic-specific transcription factor special AT-rich sequence-binding protein 2 (SATB2), cytoskeletal protein cytokeratin 7 (CK7), and immune checkpoint molecule programmed death-ligand 1 (PD-L1). We analyzed a cohort of 285 patients with surgically treated CRC for quantitative associations among the three markers and five traditional prognostic indicators (i.e., tumor stage, histological grade, variant morphology, laterality, and mismatch-repair/MMR status). The results showed that loss of SATB2 expression had significant negative prognostic implications relative to overall survival (OS) and cancer-specific survival (CSS), significantly shortened 5 years OS and CSS and 10 years CSS in patients with CRC expressing CK7, and borderline insignificantly shortened OS in patients with PD-L1 + CRC. PD-L1 showed a significant negative impact in cases with strong expression (membranous staining in 50-100% of tumor cells). Loss of SATB2 was associated with CK7 expression, advanced tumor stage, mucinous or signet ring cell morphology, high grade, right-sided localization but was borderline insignificant relative to PD-L1 expression. CK7 expression was associated with high grade and SATB2 loss. Additionally, a separate analysis of 248 neoadjuvant therapy-naïve cases was performed with mostly similar results. The loss of SATB2 and CK7 expression were significant negative predictors in the multivariate analysis adjusted for associated parameters and patient age. In summary, loss of SATB2 expression and gain of CK7 and strong PD-L1 expression characterize an aggressive phenotype of CRC.

Prognostic value of Talin-1 in renal cell carcinoma and its association with B7-H3

METHODS: Talin-1 protein was demonstrated as a potential prognostic marker in renal cell carcinoma (RCC) using bioinformatics analysis. We, therefore, examined the protein expression levels and prognostic significance of Talin-1 with a clinical follow-up in a total of 269 tissue specimens from three important subtypes of RCC and 30 adjacent normal samples using immunohistochemistry. Then, we used combined analysis with B7-H3 to investigate higher prognostic values. RESULTS: The results showed that high membranous and cytoplasmic expression of Talin-1 was significantly associated with advanced nucleolar grade, microvascular invasion, histological tumor necrosis, and invasion to Gerota’s fascia in clear cell RCC (ccRCC). In addition, high membranous and cytoplasmic expression of Talin-1 was found to be associated with significantly poorer disease-specific survival (DSS) and progression-free survival (PFS). Moreover, increased cytoplasmic expression of Talin-1High/B7-H3High compared to the other phenotypes was associated with tumor aggressiveness and progression of the disease, and predicted a worse clinical outcome, which may be an effective biomarker to identify ccRCC patients at high risk of recurrence and metastasis. CONCLUSIONS: Collectively, these observations indicate that Talin-1 is an important molecule involved in the spread and progression of ccRCC when expressed particularly in the cytoplasm and may serve as a novel prognostic biomarker in this subtype. Furthermore, a combined analysis of Talin-1/B7-H3 indicated an effective biomarker to predict the progression of disease and prognosis in ccRCC.

Pan-TRK Immunohistochemistry and NTRK Gene Fusions in Primary Carcinomas of the Liver

Gene fusions involving NTRK are not common in solid tumors. The aim of this study was to investigate the TRK protein expression and molecular characteristics of gene fusions in primary liver carcinomas. A total of 110 hepatocellular carcinomas (HCC) and 69 intrahepatic cholangiocarcinomas were retrieved for tissue microarray (TMA) construction and clinicopathologic characterization. Immunohistochemistry (IHC) for pan-TRK was initially performed on TMA slides and evaluated for staining intensity. Twelve (10.9%) of 110 HCC showed weak cytoplasmic TRK expression by IHC on TMA, while all others, including 69 intrahepatic cholangiocarcinomas, were negative for TRK. The TRK expression did not correlate with patient's age, sex, tumor differentiation, or tumor stage. The 12 cases were then validated by IHC on whole sections but all turned out to be negative. Further, RNA sequencing analysis did not detect any NTRK fusions in all 12 HCC cases; however, it did identify many fusions frequently involving genes that encode mitochondrial and ribosomal proteins, microRNAs, and some transcription factors. A few fusions were recurrent, including MT-ATP6/MT-ATP8 fusion (n=9, 75%), Ig κ light chain gene IGKV/IGKJ fusion (n=5, 41.7%), and histocompatibility complex gene HLA-C/HLA-B fusion (n=4, 33.3%). In summary, NTRK fusion is very rare in primary liver carcinomas. IHC on TMA for TRK expression yields high false positive results, which should be validated on whole sections and confirmed by molecular genetic studies such as RNA sequencing. Many fusions involving genes other than NTRK are detected in HCC, the significance of which warrants further studies.

Co-expression of cancer-testis antigens of MAGE-A6 and MAGE-A11 is associated with tumor aggressiveness in patients with bladder cancer

Melanoma antigen gene (MAGE)-A6 and MAGE-A11 are two of the most cancer-testis antigens overexpressed in various types of cancers. However, the clinical and prognosis value of MAGE-A6 and MAGE-A11 co-expression in the pathophysiology of the bladder is unknown. Three studies were selected from GEO databases in order to introduce the common genes that are involved in bladder cancer. Then immunohistochemical analysis for staining pattern and clinicopathological significance of suggested markers, MAGE-A6 and MAGE-A11, were performed in 199 and 213 paraffin-embedded bladder cancer with long adjacent normal tissues, respectively. A significant and positive correlation was found between both nuclear and cytoplasmic expressions of MAGE-A6 as well as expression of cytoplasmic MAGE-A11 with histological grade, PT stage, lamina propria invasion, and LP/ muscularis (L/M) involvement (all of the p-values in terms of H-score were < 0.0001). Additionally, significant differences were found between both nuclear and cytoplasmic MAGE-A6/MAGE-A11 phenotypes with tumor size (P = 0.007, P = 0.043, respectively), different histological grades, PT stage, LP involvement, and L/M involvement (all of the p-values for both phenotypes were < 0.0001). The current study added the value of these novel markers to the bladder cancer clinical settlement that might be considered as an admirable target for immunotherapy.

Cytokeratin 7 expression as a predictor of an unfavorable prognosis in colorectal carcinoma

Colorectal carcinoma (CRC) is associated with significant morbidity and mortality worldwide. Cytokeratins (CKs) are widely expressed in various types of carcinomas, whereas in CRC it is usually CK7 − and CK20 + . A subset of CRCs is CK7 + . This study aims to determine the prevalence of CK7 expression in CRC and its impact on overall survival. We analyzed 300 randomly selected surgically treated CRC cases using paraffin embedded tumor tissue samples and evaluated CK7 and CK20 expression using the tissue microarray method. Tumors with positivity > 10% and > 25% of tumor cells were considered CK7 and CK20 positive, respectively. Expression of both CKs and several clinical-pathological variables (stage, grade, laterality, mismatch-repair/MMR status) were evaluated using patient follow up data (Kaplan–Meier analysis of cancer-specific survival (CSS)). Significant results include shorter CSS (restricted mean 4.98 vs. 7.74 years, P = 0.007) and 5-year survival (29.4% vs. 64.6%, P = 0.0221) in CK7 + tumors compared to CK7 − tumors, respectively; without significant association with grade, stage or right-sided location. These results were significant in a multivariate analysis. CK20 + tumors are more frequently MMR-proficient and left-sided. MMR-deficient tumors are more frequently right-sided and had longer survival. CK7 expression, right-sided location (rmean CSS 6.83 vs. 8.0 years, P = 0.043), MMR-proficiency (rmean CSS 7.41 vs. 9.32 years, P = 0.012), and UICC stages III + IV (rmean CSS 6.03 vs. 8.92 years, P < 0.001) of the tumor correlated with negative prognostic outcomes, whereas the most significant results concern stage and CK7 positivity. The result concerning negative prognostic role of CK7 differs from those obtained by several previous studies focused on this topic.

Heat Shock Proteins 27, 70, and 110: Expression and Prognostic Significance in Colorectal Cancer

Heat shock proteins (HSPs) are evolutionarily conserved chaperones occurring in virtually all living organisms playing a key role in the maintenance of cellular homeostasis. They are constitutively expressed to prevent and repair protein damage following various physiological and environmental stressors. HSPs are overexpressed in various types of cancers to provide cytoprotective function, and they have been described to influence prognosis and response to therapy. Moreover, they have been used as a tumor marker in blood serum biochemistry and they represent a potentially promising therapeutic target. To clarify prognostic significance of two canonical HSPs (27 and 70) and less known HSP110 (previously known as HSP105) in colorectal carcinoma (CRC), we retrospectively performed HSP immunohistochemistry on tissue microarrays from formalin-fixed paraffin-embedded tumor tissue from 297 patients with known follow-up. Survival analysis (univariate Kaplan-Meier analysis with the log-rank test and multivariate Cox regression) revealed significantly shorter overall survival (OS, mean 5.54 vs. 7.07, p = 0.033) and borderline insignificantly shorter cancer specific survival (CSS, mean 6.3 vs. 7.87 years, p = 0.066) in patients with HSP70+ tumors. In the case of HSP27+ tumors, there was an insignificantly shorter OS (mean 6.36 vs. 7.13 years, p = 0.2) and CSS (mean 7.17 vs. 7.95 years, p = 0.2). HSP110 showed no significant impact on survival. Using Pearson's chi-squared test, there was a significant association of HSP27 and HSP70 expression with advanced cancer stage. HSP27+ tumors were more frequently mismatch-repair proficient and vice versa (p = 0.014), and they occurred more often in female patients and vice versa (p = 0.015). There was an enrichment of left sided tumors with HSP110+ compared to the right sided (p = 0.022). In multivariate Cox regression adjusted on the UICC stage, grade and right/left side; both HSPs 27 and 70 were not independent survival predictors (p = 0.616 & p = 0.586). In multivariate analysis, only advanced UICC stage (p = 0) and right sided localization (p = 0.04) were independent predictors of worse CSS. In conclusion, from all three HSPs examined in our study, only HSP70 expression worsened CRC prognosis, although stage-dependent. The contribution of this article may be seen as a large survival analysis of HSPs 27 and 70 and the largest analysis of HSP110 described in CRC.

Validity and Reproducibility of Immunohistochemical Scoring by Trained Non-Pathologists on Tissue Microarrays

BACKGROUND

Scoring of immunohistochemistry (IHC) staining is often done by non-pathologists, especially in large-scale tissue microarray (TMA)-based studies. Studies on the validity and reproducibility of scoring results from non-pathologists are limited. Therefore, our main aim was to assess interobserver agreement between trained non-pathologists and an experienced histopathologist for three IHC markers with different subcellular localization (nucleus/membrane/cytoplasm).

METHODS

Three non-pathologists were trained in recognizing adenocarcinoma and IHC scoring by a senior histopathologist. Kappa statistics were used to analyze interobserver and intraobserver agreement for 6,249 TMA cores from a colorectal cancer series.

RESULTS

Interobserver agreement between non-pathologists (independently scored) and the histopathologist was "substantial" for nuclear and membranous IHC markers (κ_range = 0.67-0.75 and κ_range = 0.61-0.69, respectively), and "moderate" for the cytoplasmic IHC marker (κ_range = 0.43-0.57). Scores of the three non-pathologists were also combined into a "combination score" (if at least two non-pathologists independently assigned the same score to a core, this was the combination score). This increased agreement with the pathologist (κ_nuclear = 0.74; κ_membranous = 0.73; κ_cytopasmic = 0.57). Interobserver agreement between non-pathologists was "substantial" (κ_nuclear = 0.78; κ_membranous = 0.72; κ_cytopasmic = 0.61). Intraobserver agreement of non-pathologists was "substantial" to "almost perfect" (κ_{nuclear,range} = 0.83-0.87; κ_{membranous,range} = 0.75-0.82; κ_cytopasmic = 0.69). Overall, agreement was lowest for the cytoplasmic IHC marker.

CONCLUSIONS

This study shows that adequately trained non-pathologists are able to generate reproducible IHC scoring results, that are similar to those of an experienced histopathologist. A combination score of at least two non-pathologists yielded optimal results.

IMPACT

Non-pathologists can generate reproducible IHC results after appropriate training, making analyses of large-scale molecular pathological epidemiology studies feasible within an acceptable time frame.

High expression of tumor susceptibility gene 101 (TSG101) is associated with more aggressive behavior in colorectal carcinoma

INTRODUCTION

Identification of genetic determinants such as exosomal content that drives progression and metastasis of colorectal cancer (CRC) has received considerable attention. The present study aims to identify a suitable biomarker in CRC tissues and exosomes based on bioinformatics data to evaluate its expression patterns in CRC tissues as well as its clinicopathological significance.

MATERIALS AND METHODS

Protein-protein interaction (PPI) network and enrichment analysis were applied to identify up-regulated genes that contributed in CRC exosomes to select the marker. The expression patterns and clinical significance of selected exosomal marker were evaluated in tissue microarrays (TMAs) of 445 CRC tumors and 39 adjacent normal tissues using immunohistochemistry method.

RESULTS

Based on bioinformatics data, TSG101 gene was prominent amongst the tumor tissues and exosomes. Expression of TSG101 was significantly up-regulated in tumor cells compared to adjacent normal tissues (p-value = 0.04). Moreover, higher expressions of TSG101 (cytoplasmic and nuclear) were significantly associated with tumor differentiation (p-value = 0.042) and distant metastasis (p-value = 0.027). A significant association was found in the cytoplasmic expression of TSG101 between well and moderate tumor differentiation (p-value = 0.005) as well as moderate and poor differentiation (p-value = 0.050).

CONCLUSION

These findings indicate that the exploration of crosstalk between exosome content and CRC may be valuable for the development of novel exosomal biomarkers. Increased expression of TSG101, as a promising exosome marker, is more associated with more aggressive tumor behaviors, metastasis, and progression of CRC, which paves the way for therapeutic strategies and CRC management. However, further investigations are warranted to clarify the molecular mechanisms of TSG101 in CRC.

SHP2 regulates the development of intestinal epithelium by modifying OSTERIX+ crypt stem cell self-renewal and proliferation

The protein tyrosine phosphatase SHP2, encoded by PTPN11, is ubiquitously expressed and essential for the development and/or maintenance of multiple tissues and organs. SHP2 is involved in gastrointestinal (GI) epithelium development and homeostasis, but the underlying mechanisms remain elusive. While studying SHP2's role in skeletal development, we made osteoblast-specific SHP2 deficient mice using Osterix (Osx)-Cre as a driver to excise Ptpn11 floxed alleles. Phenotypic characterization of these SHP2 mutants unexpectedly revealed a critical role of SHP2 in GI biology. Mice lacking SHP2 in Osx⁺ cells developed a fatal GI pathology with dramatic villus hypoplasia. OSTERIX, an OB-specific zinc finger-containing transcription factor is for the first time found to be expressed in GI crypt cells, and SHP2 expression in the crypt Osx+ cells is critical for self-renewal and proliferation. Further, immunostaining revealed the colocalization of OSTERIX with OLFM4 and LGR5, two bona fide GI stem cell markers, at the crypt cells. Furthermore, OSTERIX expression is found to be associated with GI malignancies. Knockdown of SHP2 expression had no apparent influence on the relative numbers of enterocytes, goblet cells or Paneth cells. Given SHP2's key regulatory role in OB differentiation, our studies suggest that OSTERIX and SHP2 are indispensable for gut homeostasis, analogous to SOX9's dual role as a master regulator of cartilage and an important regulator of crypt stem cell biology. Our findings also provide a foundation for new avenues of inquiry into GI stem cell biology and of OSTERIX's therapeutic and diagnostic potential.

A four-antibody immunohistochemical panel can distinguish clinico-pathological clusters of urothelial carcinoma and reveals high concordance between primary tumor and lymph node metastases

Urothelial carcinoma of the bladder (UC) has a poor prognosis, partly because of chemotherapy resistance. Molecular classifications have shown their interest and can help to offer personalized treatment. In this study, we evaluated the feasibility of an immunohistochemical study to divide advanced UC into clinico-pathological-molecular subgroups and evaluate phenotypic correspondence between primary UC and matched lymph node metastases (LMN). An eight-antibody immunohistochemical panel was performed on UC and matched LMN from patients treated with radical cystectomy. One hundred eighty-seven UCs (100 pN0 tumor and 87 pN+ tumor) were tested. Multiple correspondence analysis showed that UC expressing GATA3 also expressed FOXA1 (p = 0.010) and did not stain for CK5/6 (p = 0.031) nor CK14 (p = 0.003). UC expressing CK14 coexpressed CK5/6 (p < 0.0001), had high Ki67 (p = 0.010) and no GATA3 (p = 0.003) nor FOXA1 (p = 0.011) expression. Loss of expression of STAG2 was associated with high Ki67 (p = 0.001). Sixty-seven percent of [CK5/6 CK14]+ [GATA3 FOAXA1]- patients had high Ki67 expression vs 37% of [GATA3 FOXA1]+ [CK5/6 CK14]- patients (p = 0.024). The majority of [CK5/6 CK14]+ [GATA3 FOAXA1]- patients (92%) had advanced disease (pT3-pT4) whilst 86% of pT1-T2 cases were [GATA3 FOXA1]+ [CK5/6 CK14]- (p = 0.041). Differential antigen expression between 63 pN+ primary tumors and their corresponding LNM showed the following concordance percentages: p53 (76%), p63 (75%), CK5/6 (65%), CK14 (89%), GATA3 (75%), FOXA1 (68%), STAG2 (65%), and Ki-67 (71%). These results support the interest of immunohistochemistry for subtype profiling in metastatic UC, using CK5/6, CK14, GATA3, and FOXA1, highlighting also few phenotypical modifications when tumor spreads to lymph nodes.

Overexpression and translocation of dynamin 2 promotes tumor aggressiveness in breast carcinomas

Dynamin 2 is a GTPase protein that has been implicated in cancer progression through its various roles such as endocytosis, morphogenesis, epithelial-mesenchymal transition (EMT), cellular contractions, and focal adhesion maturation. The increased expression levels of this molecule have been demonstrated with the development of several cancers such as prostate, pancreas, and bladder. However, its clinical significance in breast cancer is unclear yet. In the present study, the membranous, cytoplasmic, and nuclear expression levels of dynamin 2 molecule were evaluated for the first time, using immunohistochemistry (IHC) on tissue microarray (TMA) slides in 113 invasive breast cancer tissues. Moreover, afterward, the association between the dynamin 2 expression and clinicopathological features was determined. Our finding showed that, a higher nuclear expression of dynamin 2 is significantly associated with an increase in tumor stage (P = 0.05), histological grade (P = 0.001), and age of the patients (P = 0.03). In addition, analysis of the cytoplasmic expression levels of this molecule revealed that, there was a statistically significant difference between the expression levels of dynamin 2 among the different breast cancer subtypes (P = 0.003). Moreover, a significant association was found between the increased expression of dynamin 2 membranous and vascular invasion (VI) (P = 0.02). We showed that dynamin 2 protein expression has an association with more aggressive tumor behavior and more advanced disease in the patients with breast cancer; therefore, dynamin 2 molecule could be considered as an indicator of disease progression and aggressiveness.

"Analysis of immunohistochemical expression of epidermal growth factor receptor in oral squamous cell carcinoma using tissue microarray technology and whole sections:" A comparative study

BACKGROUND

Oral squamous cell carcinoma (OSCC) accounts for more than 90% of all oral cancers. Epidermal growth factor receptor (EGFR) dysregulation is associated with essentially all of the key features of cancer. Tissue microarrays (TMAs) allow the simultaneous analysis of many tumours using small-diameter cores sampled from larger blocks of tissue. Hence present study was taken up to validate TMA technology.

AIMS AND OBJECTIVES

To analyse and compare the immunohistochemical (IHC) expression of EGFR in OSCC using TMA technology and in whole tissue sections.

MATERIALS AND METHODS

Study included 34 cases of OSCC.Three tissue cores, each 1 mm in diameter were placed into a recipient paraffin block using a precision microarray instrument finally containing 102 spots. EGFR expression was analysed. Agreement between whole sections and TMA scores was analysed using Cohen's weighted Kappa.

RESULTS

EGFR expression was seen in 61.8% of whole section cases. In TMA out of 102 cores 75.50 % of the disks were confirmed to represent an adequate amount of tumor tissue. In TMA 48.5% cases showed EGFR expression.The EGFR expression of whole.

CONCLUSION

Some OSCC express high EGFR and this expression may be an independent Wfactor of certain clinico-pathological variables. TMA may be used as an adjunct with conventional method of evaluation of OSCC especially in larger sample sized studies keeping in mind its limitations.

Low level expression of human telomerase reverse transcriptase predicts cancer-related death and progression in embryonal carcinoma

INTRODUCTION

hTERT (human telomerase reverse transcriptase) is a catalytic subunit of the enzyme telomerase and has a role in cell proliferation, cellular senescence, and human aging.

MATERIALS AND METHODS

The purpose of this study was to evaluate the expression and significance of hTERT protein expression as a prognostic marker in different histological subtypes of testicular germ cell tumors (TGCTs), including 46 embryonal carcinomas, 46 yolk sac tumors, 38 teratomas, 84 seminomas as well as two main subtypes of seminomas and non-seminomas using tissue microarray (TMA) technique.

RESULTS

The results showed that there is a statistically significance difference between the expression of hTERT and various histological subtypes of TGCTs (P < 0.001). In embryonal carcinoma, low level expression of hTERT protein was significantly associated with advanced pT stage (P = 0.023) as well as tunica vaginalis invasion (P = 0.043). Moreover, low level expression of hTERT protein was found to be a significant predictor of worse DSS (log rank: P = 0.011) and PFS (log rank: P = 0.011) in the univariate analysis. Additionally, significant differences were observed (P =0.021, P =0.018) with 5-year survival rates for DSS and PFS of 66% and 70% for moderate as compared to 97% and 97% for high hTERT protein expression, respectively.

CONCLUSION

We showed that hTERT protein expression was associated with more aggressive tumor behavior in embryonal carcinoma patients. Also, hTERT may be a novel worse prognostic indicator of DSS or PFS, if the patients are followed up for more time periods.

Preoperative, biopsy-based assessment of the tumour microenvironment in patients with primary operable colorectal cancer

The tumour microenvironment (TME) is recognised as an important prognostic characteristic and therapeutic target in patients with colorectal cancer (CRC). However, assessment generally utilises surgically resected specimens, precluding neoadjuvant targeting. The present study investigated the feasibility of intra‐epithelial CD3⁺ T‐lymphocyte density and tumour stroma percentage (TSP) assessment using preoperative colonoscopic biopsies from 115 patients who had undergone resection of stages I–III CRC, examining the relationship between biopsy and surgically resected specimen‐based assessment, and the relationship with cancer‐specific survival (CSS). High biopsy CD3⁺ density was associated with high CD3⁺ density in the invasive margin, cancer stroma and intra‐epithelial compartments of surgically resected specimens (area under the curve > 0.62, p < 0.05 for all) and with high Immunoscore. High biopsy TSP predicted high TSP in resected specimens (p = 0.001). Intra‐class correlation coefficient for both measures was >0.7 (p < 0.001), indicating excellent concordance between individuals. Biopsy CD3⁺ density (hazard ratio [HR] 0.23, p = 0.002) and TSP (HR 2.23, p = 0.029) were independently associated with CSS; this was comparable to the prognostic value of full section assessment (HR 0.21, p = 0.004, and HR 2.25, p = 0.033 respectively). These results suggest that assessment of the TME is comparable in biopsy and surgically resected specimens from patients with CRC, and biopsy‐based assessment could allow for stratification prior to surgery or commencement of therapy targeting the TME.

The clinical and biological significance of HER2 over-expression in breast ductal carcinoma in situ: a large study from a single institution

BACKGROUND

Previous studies have reported up to 50% of ductal carcinoma in situ (DCIS), is HER2 positive, but the frequency of HER2-positive invasive breast cancer (IBC) is lower. The aim of this study is to characterise HER2 status in DCIS and assess its prognostic value.

METHODS

HER2 status was evaluated in a large series of DCIS (n = 868), including pure DCIS and DCIS associated with IBC, prepared as tissue microarrays (TMAs). HER2 status was assessed using immunohistochemistry (IHC) and chromogenic in situ hybridisation (CISH).

RESULTS

In pure DCIS, HER2 protein was over-expressed in 9% of DCIS (3+), whereas 15% were HER2 equivocal (2+). Using CISH, the final HER2 status was positive in 20%. In mixed DCIS, HER2 amplification of the DCIS component was detected in 15% with amplification in the invasive component of only 12%. HER2-positive DCIS was associated with features of aggressiveness (p < 0.0001) and more frequent local recurrence (p = 0.03). On multivariate analysis, combined HER2+/Ki67+ profile was an independent predictor of local recurrence (p = 0.006).

CONCLUSIONS

The frequency of HER2 positivity in DCIS is comparable to IBC- and HER2-positive DCIS is associated with features of poor prognosis. The majority of HER2 over-expression in DCIS is driven by gene amplification.

Genome-wide DNA methylation differences according to oestrogen receptor beta status in colorectal cancer

Involvement of sex hormones in colorectal cancer (CRC) development has been linked to oestrogen receptor β (ERβ). Expression of ERβ is found reduced in tumour tissue and inversely related to mortality. However, mechanisms are not well understood. Our study aimed to detect differentially methylated genes associated with ERβ expression, which could point to mechanisms by which ERβ could influence risk and prognosis of CRC. Epigenome-wide DNA methylation profiling was performed using Illumina HumanMethylation450k BeadChip arrays in two independent tumour sample sets of CRC patients recruited in 2003-2010 by the German DACHS study (discovery cohort n = 917, replication cohort n = 907). ERβ expression was measured using immunohistochemistry and scored as negative, moderate and high. Differentially methylated CpG sites and genomic regions were determined using limma in the R-package RnBeads. For the comparison of tumours with moderate/high ERβ versus negative expression, differentially methylated CpG sites were identified but not confirmed by replication. Comparing tumours of high with tumours of negative ERβ expression revealed 2,904 differentially methylated CpG sites of which 403 were replicated (FDR adjusted p-value<0.05). Replicated CpGs were annotated to genes such as CD36, HK1 or LRP5. A survival analysis indicates that 30 of the replicated CpGs are also associated with overall survival (FDR-adjusted p-value<0.05). The regional analysis identified 60 differentially methylated promotor regions. The epigenome-wide analysis identified both novel genes as well as genes already implicated in CRC. Follow-up mechanistic studies to better understand the regulatory role of ERβ could inform potential targets for improving treatment or prevention of CRC.

An analysis of a multiple biomarker panel to better predict prostate cancer metastasis after radical prostatectomy

A plethora of individual candidate biomarkers for predicting biochemical relapse in localized prostate cancer (PCa) have been proposed. Combined biomarkers may improve prognostication, and ensuring validation against more clinically relevant endpoints are required. The Australian PCa Research Centre NSW has contributed to numerous studies of molecular biomarkers associated with biochemical relapse. In the current study, these biomarkers were re-analyzed for biochemical relapse, metastatic relapse and PCa death with extended follow-up. Biomarkers of significance were then used to develop a combined prognostic model for clinical outcomes and validated in a large independent cohort. The discovery cohort (n = 324) was based on 12 biomarkers with a median follow-up of 16 years. Seven biomarkers were significantly associated with biochemical relapse. Three biomarkers were associated with metastases: AZGP1, Ki67 and PML. Only AZGP1 was associated with PCa death. In their individual and combinational forms, AZGP1 and Ki67 as a dual BM signature was the most robust predictor of metastatic relapse (AUC 0.762). The AZPG1 and Ki67 signature was validated in an independent cohort of 347 PCa patients. The dual BM signature of AZGP1 and Ki67 predicted metastasis in the univariable (HR 7.2, 95% CI, 1.6-32; p = 0.01) and multivariable analysis (HR 5.4, 95% CI, 1.2-25; p = 0.03). The dual biomarker signature marginally improved risk prediction compared to AZGP1 alone (AUC 0.758 versus 0.738, p < 0.001). Our findings indicate that biochemical relapse is not an adequate surrogate for metastasis or PCa death. The dual biomarker signature of AZGP1 and Ki67 offers a small benefit in predicting metastasis over AZGP1 alone.

Human telomerase reverse transcriptase protein expression predicts tumour aggressiveness and survival in patients with clear cell renal cell carcinoma

Human telomerase reverse transcriptase (hTERT) is an active component of telomerase and responsible for its catalytic activity, associated with cell proliferation and differentiation. For the first time, the present study was conducted to evaluate the expression and prognostic significance of hTERT in different histological subtypes of renal cell carcinoma (RCC). Expression of hTERT was examined in 176 well-defined renal tumour samples including clear cell RCCs (ccRCCs), papillary and chromophobe RCCs using immunohistochemistry on tissue microarrays. The association between hTERT expression and clinicopathological parameters as well as survival outcomes were then analysed. There was a statistically significant difference in terms of hTERT expression among various RCC subtypes. In ccRCC, increased expression of hTERT was significantly associated with advanced stage, higher grade, presence of microvascular invasion, lymph node invasion, and metastasis. Moreover, in the multivariate analysis, tumour stage and tumour size were independent predictors of the disease-specific survival (DSS). Additionally, expression of hTERT was found to be a significant predictor of worse DSS (p = 0.012) in the univariate analysis. In papillary carcinoma samples (type I and II), significant association was detected between hTERT expression and the tumour stage (p = 0.010, p = 0.050), respectively. In chromophobe RCC, no significant association was detected between expression of hTERT and clinicopathological parameters and survival data. We showed that hTERT protein expression was associated with more aggressive tumour behaviour and more advanced disease in ccRCC patients. Also, hTERT may be a novel poor prognostic indicator of DSS, if the patients are followed for more prolonged time periods.

Impact of CDX2 expression status on the survival of patients after curative resection for colorectal cancer liver metastasis

BACKGROUND

The prognostic biomarker for patients undergoing curative liver metastasectomy for colorectal cancer (CRC) is lacking. The purpose was to investigate the prognostic role of a lack of CDX2 expression, which has been proposed as a potential biomarker for high-risk relapse in early-stage CRC, in patients undergoing curative liver metastasectomy.

METHODS

A total of 396 consecutive patients with CRC liver metastasis who underwent potentially curative liver metastasectomy at a single center in Japan between 2005 and 2015 were included. For the immunohistochemical analysis of nuclear CDX2 expression, we adopted the tissue microarray approach using the resected metastatic liver CRCs. Patient subgroups were compared with respect to disease-free survival (DFS) and overall survival (OS) by applying the Kaplan-Meier curve, log-rank tests, and multivariate analyses based on the Cox proportional hazards method. OS is defined as the period from the date of curative liver resection for metastatic CRC until death. DFS is defined as the length of time from curative liver resection to either the first recurrence or death. In patients without recurrence, the latest imaging inspection date was used as the censored date.

RESULTS

Thirty-six of the 396 CRCs (9.1%) reduced CDX2 expression. The reduced expression of CDX2 was associated with poor differentiation (P = 0.02). DFS in days was lower in the patients with CDX2-low CRC than in the patients with CDX2-high CRC (median DFS: 245 days versus 420 days; hazard ratio for disease recurrence: 1.64; 95% confidence interval: 1.08-2.38; P = 0.02). OS in days was lower in the patients with CDX2-low CRC than in the patients with CDX2-high CRC (median OS: 1024 days versus 3145 days; hazard ratio: 2.41; 95% confidence interval: 1.52-3.85; P <  0.001). In patients with CDX2-low CRC, both DFS and OS were similar between the with and without pre- or post-operative chemotherapy groups (median DFS: 243 versus 247 days; P = 0.73, median OS: 1016 versus 1363 days; P = 0.69).

CONCLUSIONS

Reduced expression of CDX2 indicates poor DFS and OS, however, it might not represent chemosensitivity in patients undergoing curative liver metastasectomy. (339/350).

TGR5 expression in normal kidney and renal neoplasms

BACKGROUND

The G protein-coupled bile acid receptor (TGR5) is a cell surface receptor which induces the production of intracellular cAMP and promotes epithelial-mesenchymal transition in gastric cancer cell lines. TGR5 is found in a wide variety of tissues including the kidney. However, the patterns of TGR5 expression have not been well characterized in physiologic kidney or renal neoplasms. We explore the expression of TGR5 in benign renal tissue and renal neoplasms and assess its utility as a diagnostic marker.

METHODS

Sixty-one renal cortical neoplasms from 2000 to 2014 were retrieved. TGR5 protein expression was examined by immunohistochemistry. TGR5 mRNA was also measured by real-time PCR.

RESULTS

In normal renal tissue, TGR5 was strongly positive in collecting ducts, distal convoluted tubules and thin loop of Henle. Proximal convoluted tubules showed absent or focal weak staining. In clear cell renal cell carcinomas (RCCs), 25 of 27 cases (92%) were negative for TGR5 (p < 0.001). TGR5 mRNA was also significantly decreased in clear cell RCCs, suggesting that decreased TGR5 protein expression may be attributable to the downregulation of TGR5 mRNA in these tumors. All 11 papillary RCCs expressed TGR5 with 45% (5/11) exhibiting moderate to strong staining. All chromophobe RCCs and oncocytomas were positive for TGR5 with weak to moderate staining. TGR5 mRNA expression in these tumors was similar to normal kidney. All urothelial carcinomas of the renal pelvis strongly expressed TGR5 including a poorly differentiated urothelial carcinoma with sarcomatoid features.

CONCLUSION

TGR5 is strongly expressed in collecting ducts, distal convoluted tubules and thin loop of Henle. TGR5 protein and mRNA expression were notably decreased in clear cell RCCs and may be helpful in differentiating these tumors from other RCCs.

Receptor tyrosine kinase amplified gastric cancer: Clinicopathologic characteristics and proposed screening algorithm

Although targeted therapy for receptor tyrosine kinases (RTKs) of advanced gastric cancers (AGCs) has been in the spotlight, guidelines for the identification of RTK-amplified gastric cancers (RA-GCs) have not been established. In this study, we investigate clinicopathologic characteristics of RA-GCs and propose a screening algorithm for their identification. We performed immunohistochemistry (IHC) for MLH1, MSH2, PMS2, MSH6, key RTKs (EGFR, HER2, MET), and p53, in situ hybridization for Epstein-Barr virus encoding RNA, and silver in situ hybridization (SISH) for EGFR, HER2, and MET using tissue microarrays of 993 AGCs. On IHC, 157 (15.8%) 61, (6.15%), and 85 (8.56%) out of 993 cases scored 2+ or 3+ for EGFR, HER2, and MET, respectively. On SISH, 31.2% (49/157), 80.3% (49/61), and 30.6% (26/85) of 2+ or 3+ cases on IHC showed amplification of the corresponding genes. Of the 993 cases, 104 were classified as RA-GCs. RA-GC status correlated with older age (P < 0.001), differentiated histology (P = 0.001), intestinal or mixed type by Lauren classification (P < 0.001), lymphovascular invasion (P = 0.026), and mutant-pattern of p53 (P < 0.001). The cases were divided into four subgroups using two classification systems, putative molecular classification and histologic-molecular classification, based on Lauren classification, IHC, and SISH results. The histologic-molecular classification showed higher sensitivity for identification of RA-GCs and predicted patient prognosis better than the putative molecular classification. In conclusion, RA-GCs show unique clinicopathologic features. The proposed algorithm based on histologic-molecular classification can be applied to select candidates for genetic examination and targeted therapy.

Usefulness of Immunohistochemistry for Microsatellite Instability Screening in Gastric Cancer

BACKGROUND/AIMS

The usefulness of immunohistochemistry to screen for the microsatellite instability (MSI) phenotype in gastric cancer remains unclear. Moreover, the prognostic value of MSI phenotypes in gastric cancer has been debated.

METHODS

The clinicopathologic parameters and survival outcomes of 203 MSI-high (MSI-H) and 261 microsatellite-stable (MSS) advanced gastric cancers (AGCs) were compared. Next, we compared the immunohistochemistry results for hMLH1 and hMSH2 with those of a polymerase chain reaction (PCR)-based method. Kaplan-Meier curves and a Cox proportional hazard regression model were used to conduct survival analyses.

RESULTS

The MSI-H AGCs were correlated with older age (p<0.001), female gender (p=0.018), distal location (p<0.001), larger size (p=0.016), and intestinal type (p<0.001). Multivariate analysis revealed that the MSI-H phenotype was an independent favorable factor that was related to overall survival in patients with AGC (p<0.001). Compared with the PCR-based analysis, immunohistochemistry exhibited high sensitivity (91.1%) and specificity (98.5%) in the detection of MSI phenotypes.

CONCLUSIONS

MSI-H gastric cancers have distinct clinicopathologic features and better prognoses, which suggests the necessity of MSI analysis in gastric cancer. Immunohistochemistry can be a useful and reliable screening method in the assessment of MSI status in gastric cancer.

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.

Determination of Tumor Heterogeneity in Colorectal Cancers Using Heterogeneity Tissue Microarrays

Cancer is often heterogeneous both on a morphological and on a genetic level. Though resected tumors are often large, molecular tumor analysis is usually restricted to one tissue block. In this project we introduce a new tool for a high-throughput heterogeneity analysis of colorectal cancer. A heterogeneity tissue microarray (TMA) was manufactured from tissues of 340 patients with colorectal cancer. For this purpose 8 different tissue spots were taken from as many different cancer blocks per patient as possible (at least 4 different blocks). Additional tissue samples from 1 to 4 corresponding lymph node metastases were added from 134 patients. The system was then validated by analysing one parameter each known for minimal (p53) or substantial (HER2) heterogeneity in colorectal cancer. P53 alterations as detected by immunohistochemistry were seen in 174 (51.3 %) of 339 analyzable primary tumors of which 23 (13.2 % of positive cases) showed a heterogeneous distribution pattern. HER2 overexpression was seen in 18 (5.4 %) of 336 evaluable tumors. HER2 amplification occurred in 6 (33.3 %) of the 18 cases with HER2 overexpression. Genomic heterogeneity was more prevalent for HER2 alterations than for p53 alterations. For immunohistochemical expression analysis, 16 of 18 positive cases were heterogeneous (88.9 %) and for amplification 3 of 6 cases (50 %) were heterogeneous. Large section validation revealed, however a considerable fraction of heterogeneous cases were due to technical artifacts. In summary, our data suggest, that heterogeneity TMAs are a powerful tool to rapidly screen for molecular heterogeneity in colorectal cancer.

Digital pathology for the validation of tissue microarrays in peripheral T-cell lymphomas

Systematic validation of construction and analysis parameters when using tissue microarray (TMA) in rare, morphologically heterogenous entities such as peripheral T-cell lymphoma (PTCL) is not reported. We describe a tissue-saving virtual TMA to predetermine the number of cores needed to represent whole tissue sections (WTS) from the same biopsies, using automated and traditional manual methods for the quantification of immunohistochemical stains. Whole paraffin hematoxylin and eosin- and immunohistochemical (CD2, CD30, and Ki-67)-stained sections from 30 PTCLs were digitalized. A virtual TMA with six 1-mm cores per slide was designed to compare agreements in the immunohistochemical scoring. Using digital image analysis and manual stereological counting, immunohistochemical positivity was quantified. Associations were analyzed using the Bland-Altman and correlation plots. In PTCL, we report that 4 cores are required to represent WTS results (ie, agreement within ±10%). High concordance was demonstrated between digital results obtained with WTS compared with 4-core virtual TMA (correlation coefficients: 0.89-0.98), and in the comparative evaluation of 4-core virtual TMA by digital image analysis versus manual stereology (correlation coefficients: 0.91 to 0.99). Virtual TMAs provide an efficient tool for optimizing and validating TMA construction parameters when planning a study. The method can be applied to the same tissues used in a subsequent formal study, without wasting scarce tissue resources. In PTCL, TMAs constructed with four 1-mm cores are representative of WTS. In parallel tests using TMAs and WTS from PTCLs, there is a high level of agreement comparing automated digital with manual stereological methods for the quantification of immunohistochemical biomarker staining.

Small bowel adenocarcinomas complicating Crohn's disease are associated with dysplasia: a pathological and molecular study

BACKGROUND

Crohn's disease (CD) is associated with an increased risk of small bowel adenocarcinoma (SBA). However, there are no guidelines for the screening and early diagnosis of SBA. Colorectal cancer associated with chronic colitis arises from dysplasia. High-risk patients benefit from surveillance colonoscopies aimed to detect dysplasia. The dysplasia-carcinoma sequence remains poorly documented in CD-associated SBA. Moreover, molecular data about SBA complicating CD and associated dysplasia are very limited. We therefore assessed dysplasia and several key molecular markers of carcinogenesis in SBA and dysplasia developed in patients with CD.

METHODS

Forty-five SBA complicating CD and 4 specimens with dysplasia without SBA were screened. In SBA, we looked for dysplasia and determined their pathological characteristics (type, grade, distribution). We also stained for mismatch repair proteins (MLH1, MSH2, MSH6, PMS2), p53, β-catenin, and p16 and looked for KRAS, BRAF and PIK3CA mutations.

RESULTS

All neoplastic lesions, except 1 lesion, were found in inflamed mucosal areas. Dysplasia was found in 20 of 41 patients with SBA (49%). Dysplasia was flat or raised, low grade or high grade, and adjacent or distant to concomitant SBA. Molecular markers of SBA carcinogenesis complicating CD were similar to those observed in chronic colitis-related colorectal cancer (KRAS, BRAF, p53, MSI), although differences were observed for β-catenin and p16. No PIK3CA mutations were observed.

CONCLUSIONS

These results suggest that there is an inflammation-dysplasia-adenocarcinoma sequence in at least half of CD-related SBA, similar to what is observed in chronic colitis-related colorectal cancer and may have implications for the prevention and treatment of this cancer.

Thymidylate synthase expression and p21(WAF1)/p53 phenotype of colon cancers identify patients who may benefit from 5-fluorouracil based therapy

Background

Studies on the expression of thymidylate synthase (TS) in colorectal cancers (CRCs) have failed to provide unequivocal prognostic or predictive information. Here, we assessed the prognostic significance of TS expression in Astler-Coller stage B2 and C CRCs defined by a p21^WAF1/p53 immunophenotype in patients subjected to 5-fluorouracil (5FU)-based adjuvant therapy.

Methods

A cohort of 189 CRCs was asssessed for TS, p21^WAF1 and p53 expression on tissue microarrays using immunohistochemistry, and associations with disease-free survival (DFS) and overall survival (OS) of the patients were assessed using univariate and multivariate analyses.

Results

TS expression led to the stratification of patients with colon cancer, but not rectal cancer, with immunophenotypes other than p21^WAF1+/p53- (referred to as P&P) into subgroups characterized by a worse (P&P TS+) and a better (P&P TS-) DFS and OS, in univariate (P = 0.006 and P = 0.005, respectively) and multivariate (P = 0.0004 and P = 0.002, respectively) analyses. The p21^WAF1+/p53- immunophenotype was associated with a favorable prognosis, irrespective of TS expression.

Conclusions

The strong association observed between the P&P TS+ immunophenotype and a worse DFS and OS suggests a predictive significance of TS expression for 5FU-based adjuvant therapy in patients with colon cancers exhibiting the P&P immunophenotype. In addition, our findings suggest that the appropriate target for assessment of TS expression as a prognostic/predictive marker is a subgroup of colon cancers with an immunophenotype other than p21^WAF1+/p53-, and that only in this subgroup high TS expression is associated with an unfavorable DFS and OS. Therefore, we suggest that assessing TS expression in conjunction with p21^WAF1/p53 immunophenotyping of colon cancers may improve the selection of patients suitable for 5FU-based adjuvant chemotherapy.

No-cost manual method for preparation of tissue microarrays having high quality comparable to semiautomated methods

Manual tissue microarray (TMA) construction had been introduced to avoid the high cost of automated and semiautomated techniques. The cheapest and simplest technique for constructing manual TMA was that of using mechanical pencil tips. This study was carried out to modify this method, aiming to raise its quality to reach that of expensive ones. Some modifications were introduced to Shebl's technique. Two conventional mechanical pencil tips of different diameters were used to construct the recipient blocks. A source of mild heat was used, and blocks were incubated at 38°C overnight. With our modifications, 3 high-density TMA blocks were constructed. We successfully performed immunostaining without substantial tissue loss. Our modifications increased the number of cores per block and improved the stability of the cores within the paraffin block. This new, modified technique is a good alternative for expensive machines in many laboratories.

Colorectal cancer risk associated with hormone use varies by expression of estrogen receptor-β

The risk of colorectal cancer is reduced among users of oral contraceptives or menopausal hormone therapy, but associations with reproductive characteristics that are markers of a woman's endogenous hormone milieu have not been consistently observed. To help understand possible mechanisms through which exogenous and endogenous hormonal exposures are involved in colorectal cancer, we assessed the risk of these malignancies according to tumor expression of estrogen receptor-β (ESR2). In a population-based study of postmenopausal women (503 cases and 721 controls matched for sex and age), immunohistochemical expression of ESR2 was determined in 445 cases of incident colorectal cancer. Unconditional logistic regression was used in case-case analyses to assess heterogeneity between risk associations according to ESR2 status and in case-control analyses to estimate associations separately for ESR2-negative and ESR2-positive tumors. For ESR2-positive tumors but not ESR2-negative tumors, colorectal cancer risk significantly decreased with duration of oral contraceptive use [per five-year increments OR ESR2-positive, 0.87, 95% confidence interval (CI), 0.77-0.99; OR ESR2-negative, 1.02, 95% CI, 0.91-1.15; Pheterogeneity = 0.07] and with duration of menopausal hormone therapy use (per five-year increments OR ESR2-positive, 0.84, 95% CI, 0.74-0.95; OR ESR2-negative, 0.94, 95% CI 0.84-1.05; Pheterogeneity = 0.06). Significant heterogeneity according to ESR2 expression was found for the association with current use of menopausal hormone therapy (<0.5 years ago; Pheterogeneity = 0.023) but not for associations with reproductive factors. In conclusion, our results suggest that hormone use decreases risk for ESR2-positive but not ESR2-negative colorectal cancer.

Expression of bile acid receptor TGR5 in gastric adenocarcinoma

Bile reflux is a risk factor in the development of intestinal metaplasia in the stomach and is believed to function as an initiator of gastric carcinogenesis. However, whether the G protein-coupled bile acid receptor TGR5 is expressed in this tumor is not known. In this study, we determined the expression of TGR5 in gastric adenocarcinoma and examined the role of TGR5 in cell proliferation. Strong TGR5 staining was present in 12% of cases of intestinal metaplasia but in no cases of normal gastric epithelium (P < 0.01). Moderate to strong TGR5 membranous and cytoplasmic staining was present in 52% of the intestinal but in only 25% of the diffuse subtype of adenocarcinomas (P < 0.001). Kaplan-Meier univariate survival analysis revealed that moderate to strong TGR5 staining was associated with decreased patient survival (P < 0.05). Treatment with taurodeoxycholic acid (TDCA, a bile acid) significantly increased thymidine incorporation in the AGS gastric adenocarcinoma cell line, suggesting that bile acids may increase cell proliferation. This increase was significantly decreased by knockdown of TGR5 with TGR5 small-interfering RNA (siRNA). In addition, overexpression of TGR5 significantly enhanced TDCA-induced increases in thymidine incorporation. TGR5 is coupled with G(q)α and Gα(i-3) proteins. TDCA-induced increase in thymidine incorporation was significantly decreased by knockdown of G(q)α and Gα(i-3) with their siRNAs. We conclude that TGR5 is overexpressed in most gastric intestinal-type adenocarcinomas, and moderate to strong TGR5 staining is associated with decreased patient survival in all gastric adenocarcinomas. Bile acids increase cell proliferation via activation of TGR5 receptors and G(q)α and Gα(i-3) proteins.

Expression of oestrogen receptor β and prognosis of colorectal cancer

BACKGROUND

Previous studies suggest that sex steroids influence colorectal cancer (CRC) carcinogenesis. The oestrogen receptor β (ERβ) is the predominantly expressed ER in the colon and loss of ERβ in CRC has been associated with advanced cancer stages.

METHODS

Information on vital status by the end of 2009 was obtained for 1262 CRC patients recruited between 2003 and 2007. The ERβ expression was immunohistochemically measured and associations of ERβ scores with overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) were evaluated using Cox proportional hazard models adjusted for prognostic factors, such as tumour stage and second primary tumours.

RESULTS

Of the 1101 tumour samples with successful measurement, 535 were ERβ negative (48.6%), 381 (34.6%) showed moderate and 185 (16.8%) showed high ERβ expression. Compared with high ERβ expression, lack of ERβ was associated with higher cancer stages as well as greater tumour extent. In multivariate analyses, ERβ negativity was associated with an increased hazard ratio for death (HR=1.61, 95% CI 1.09-2.40, P=0.02), death attributed to CRC (HR=1.54, 95% CI 0.99-2.39, P=0.06) as well as a poorer DFS (DFS HR=1.64, 95% CI 1.23-3.36, P=0.04). The associations were stronger in stage I-III patients (OS HR=2.20, 95% CI 1.28-4.06, P=0.007, DSS HR=2.38, 95% CI 1.20-5.39, P=0.02, respectively).

CONCLUSIONS

Lack of ERβ expression is associated with advanced cancer stages and independently associated with poor survival.

Combined cytoplasmic and membranous EGFR and p53 overexpression is a poor prognostic marker in early stage oral squamous cell carcinoma

OBJECTIVE

Our aim was to evaluate the expression of several molecules that regulate growth, the cell cycle and signalling pathways including EGFR, p53, p16 and p27 in oral squamous cell carcinomas (OSCC). We examined their utility as prognostic markers by relating to clinicopathological characteristics and the clinical outcome.

PATIENTS AND METHODS

Using tissue microarray technology, we analysed 67 primary OSCC and examined immunohistochemical expression of EGFR, p53, p16 and p27. Multivariate analysis was conducted to examine their role in survival.

RESULTS

Many of the markers were highly expressed in these cancers. Membranous EGFR expression in 95.2%, both membrane and cytoplasm expression in 35%, p53 expression in 61.6%, p27 expression in 89.5% and p16 expression in 27.9% of cases. In the multivariate analysis, independent prognostic influence of a lower overall survival was determined only for advanced tumour stage (P < 0.001), p53 overexpression (P = 0.004), EGFR cytoplasm and membrane co-expression location (P = 0.002) and p16 reduced expression (P = 0.002). When considering a subgroup of early stage tumours, p53 overexpression (P = 0.028) and combined membranous and cytoplasm EGFR co-expression (P = 0.039) were indicators of a lower overall survival. For disease-free survival, in addition to these three factors, the histological grade (P = 0.011) showed independent prognostic values.

CONCLUSION

The independent value of EGFR subcellular location (cytoplasm and membrane) and p53 overexpression in overall survival even in early stages of OSCC suggests that these markers may serve as reliable biological markers to identify high-risk subgroups and to guide therapy.

Comparison of in situ hybridization methods for the assessment of HER-2/neu gene amplification status in breast cancer using a tissue microarray

BACKGROUND

This project compared HER-2/neu gene status in breast cancers, as demonstrated by FISH (fluorescent in situ hybridization) and CISH (chromogenic in situ hybridization) and using a tissue microarray (TMA). The study also aimed to show whether the TMA technique could be used in clinical diagnostics, rather than remain a scientific tool.

MATERIALS AND METHODS

A TMA was constructed using 121 breast cancer specimens, 6 cores from each specimen. Demonstration and assessment of HER-2/neu gene status was by FISH (Vysis Path) and CISH (DAKO Duo CISH).

RESULTS

The 121 breast cancer specimens were divided into 3 groups by HER-2 status, as determined by immunohistochemistry. In the HER-2 negative group no amplification was observed in 36 out of 40 cases. 3 cases showed amplification by both methods and one by CISH alone. The equivocal HER-2 group showed no amplification in 30 out of 41 cases and amplification in 9 cases. One case was FISH negative CISH positive and one was discarded. In the HER-2 positive group, amplification was confirmed in 37 of the 40 cases by both methods. 3 cases were unsuitable for assessment.

CONCLUSIONS

This study indicated that CISH is a sensitive alternative to FISH in detecting HER2 gene amplification and may replace FISH in HER2 testing. Good agreement was observed between methods (98.5% - 119 out of 121 cases). Furthermore, as only 4 out of 121 cases were unsuitable for assessment (no signal or missing TMA cores) - it may be feasible to use TMA in diagnostics.

Loss of E-cadherin expression predicts disease recurrence and shorter survival in colorectal carcinoma

The traditional staging system is currently inadequate for identifying those patients with colorectal carcinoma (CRC) who carry a high risk for poor outcome. In this study, the expression of E-cadherin was evaluated in CRC to determine its correlation with clinico-pathological variables, and association with disease outcome in patients with long-term follow-up. The present series consisted of tissue samples obtained from 230 patients with stage I, II, III, or IV CRC treated during 1981-1990 at Turku University Hospital. Archival paraffin-embedded samples were used to build up tissue microarray blocks, and E-cadherin expression was assessed by immunohistochemistry using an automated staining system. Different grading systems were tested for expression of E-cadherin. Fifty-nine percent of all tumors were positive for E-Cadherin. There was no significant correlation between E-cadherin expression and gender (p < 0.83), localization (p < 0.45), tumor invasion (p < 0.32), or histologic grade (p < 0.41). However, loss of E-cadherin expression was significantly associated with older age (p < 0.03) and lymph node involvement (p < 0.02), and with borderline significance with advanced stage (p < 0.09) and tumor metastasis (p < 0.09). In univariate (Kaplan-Meier) survival analysis, positive E-cadherin significantly (p = 0.009) predicted longer disease-free survival (DFS), and the same was true with disease-specific survival (DSS) as well (p = 0.007). In multivariate (Cox) survival analysis, E-cadherin retained its significance as independent predictor of DFS (HR = 1.56; 95% CI 1.01-2.42, p = 0.043), but not DSS. A sub-group analysis revealed that E-cadherin expression also predicts DFS (p < 0.01) and DSS (p < 0.04) in stage II CRC. Our results implicate the usefulness of E-cadherin expression in predicting disease recurrence and long-term survival in CRC.