Dynamics of adipose tissue macrophage populations after gastric bypass surgery.

OBJECTIVE: This case-control study aimed to analyze the dynamics of macrophage infiltration in subcutaneous adipose tissue following bariatric surgery or conservative treatment of obesity and to clarify whether these features predict the weight loss outcome after the surgery. METHODS: Subcutaneous tissue samples taken before and 12 months after laparoscopic Roux-en-Y gastric bypass surgery (n = 39) or conservative (n = 43) treatment for obesity were analyzed. Fat cell size was determined, and with CD68 immunohistochemistry, crown-like structures (CLS) were counted and single macrophages were quantitated. RESULTS: A major decline in CLS density from 4.1 (SD 3.5) to 1.1 (SD 0.8) per 1000 fat cells (p < 0.000) was found, regardless of the degree of weight loss after the surgery. Surgery had no effect on the fraction of infiltrating single-cell macrophages in subcutaneous adipose tissue. The abundance of these macrophage populations before the intervention did not predict the degree of postsurgery weight loss or suboptimal response to the surgery. CONCLUSIONS: The effect of gastric bypass on adipose tissue inflammatory status associates closely with CLS density even in subjects with suboptimal weight loss. The study suggests that factors related to bypass surgery other than weight loss modify the inflammatory response in adipose tissue.

TLR2 and TLR4 in colorectal cancer: relationship to tumor necrosis and markers of systemic inflammation.

In colorectal cancer (CRC), systemic inflammation is associated with poor prognosis, but the underlying mechanisms are not fully characterized. Tumor necrosis may contribute to systemic inflammation by inducing interleukin (IL)-6 signaling, and proinflammatory cytokines such as IL-6 and IL-8, and matrix metalloproteinase (MMP)-8 also are linked to adverse CRC outcomes. Because Toll-like receptors (TLRs) are important mediators of inflammatory responses, we investigated the roles of TLR2 and TLR4 in CRC-associated systemic inflammatory responses, especially tumor necrosis. In 118 patients with CRC, extensive tumor necrosis was associated with low TLR4 expression in tumor cells. Tumor cell TLR4 expression was inversely correlated with serum IL-6 and MMP-8 levels, blood total leukocyte and neutrophil counts, and serum C-reactive protein levels. Tumor cell TLR2 expression was not significantly associated with necrosis or systemic inflammation, but low expression in normal mucosa was linked to high serum MMP-8 and IL-8. These findings indicate that tumor necrosis is associated with low TLR4 expression in cancer cells and that low TLR4 expression correlates with a strong systemic inflammatory response. The low TLR2 expression in normal mucosa and its association with systemic inflammation suggest that the normal mucosa may reflect or contribute to the systemic inflammatory response.

Putative anoikis resistant subpopulations are enriched in lymph node metastases and indicate adverse prognosis in colorectal carcinoma.

Anoikis refers to apoptosis induced by the loss of contact with the extracellular matrix. Anoikis resistance is essential for metastasis. We have recently shown that it is possible to quantitatively evaluate putative anoikis resistant (AR) subpopulations in colorectal carcinoma (CRC). Abundance of these multi-cell structures is an independent marker of adverse prognosis. Here, we have quantified putative AR subpopulations in lymph node (LN) metastases of CRC and evaluated their prognostic value and relationship with the characteristics of primary tumors. A case series included 137 unselected CRC patients, 54 with LN metastases. Areal densities (structures/mm2) of putative AR structures in primary tumors had been analyzed previously and now were determined from all nodal metastases (n = 183). Areal density of putative AR structures was higher in LN metastases than in primary tumors. Variation of the areal density within different LN metastases of a single patient was lower than between metastases of different patients. Abundance of putative AR structures in LN metastases was associated with shorter cancer specific survival (p = 0.013), and this association was independent of T and N stages. Abundance of putative AR structures in primary tumors and LN metastases had a cumulative adverse effect on prognosis. Enrichment of putative AR subpopulations in LN metastases suggest that in metastasis formation, there is a selection favoring cells capable of forming these structures. Higher intra-case constancy relative to inter-case variation suggests that such selection is stable in metastasis development. Our findings indirectly support the biological validity of our concept of putative AR structures.

Monocarboxylate Transporters 1 and 4 and Prognosis in Small Bowel Neuroendocrine Tumors.

Monocarboxylate transporters (MCTs) are cell membrane proteins transporting lactate, pyruvate, and ketone bodies across the plasma membrane. The prognostic role of MCTs in neuroendocrine tumors is unknown. We aimed to analyze MCT1 and MCT4 expression in small bowel neuroendocrine tumors (SB-NETs). The cohort included 109 SB-NETs and 61 SB-NET lymph node metastases from two Finnish hospitals. Tumor samples were immunohistochemically stained with MCT1 and MCT4 monoclonal antibodies. The staining intensity, percentage of positive cells, and stromal staining were assessed. MCT1 and MCT4 scores (0, 1 or 2) were composed based on the staining intensity and the percentage of positive cells. Survival analyses were performed with the Kaplan-Meier method and Cox regression, adjusted for confounders. The primary outcome was disease-specific survival (DSS). A high MCT4 intensity in SB-NETs was associated with better DSS when compared to low intensity (85.7 vs. 56.6%, p = 0.020). A high MCT4 percentage of positive cells resulted in better DSS when compared to a low percentage (77.4 vs. 49.1%, p = 0.059). MCT4 scores 0, 1, and 2 showed DSS of 52.8 vs. 58.8 vs. 100% (p = 0.025), respectively. After adjusting for confounders, the mortality hazard was lowest in the patients with a high MCT4 score. MCT1 showed no association with survival. According to our study, a high MCT4 expression is associated with an improved prognosis in SB-NETs.

Predictive value of p53, Ki67 and TLR5 in neoplastic progression of Barrett's esophagus: a matched case-control study.

Barrett's esophagus progresses to high-grade dysplasia or cancer along the well-established metaplasia-dysplasia-adenocarcinoma sequence. The aim of this study was to evaluate the value of p53, Ki67, and toll-like receptor 5 (TLR5) in prediction of malignant progression of Barrett's metaplasia and low-grade dysplasia. This was a retrospective matched case-control study based on Northern and Central Finland population. Patients diagnosed with esophageal high-grade dysplasia or adenocarcinoma were included. From these patients, all previous endoscopy samples were obtained along with original diagnostic HE-slides and clinical data. Age- and sex-matched patients with non-progressing Barrett's metaplasia and low-grade dysplasia confirmed with follow-up endoscopies were used as controls. Two gastrointestinal pathologist re-reviewed all original HE-slides, and newly made sections to confirm representative tissue material blinded from clinical data. p53, Ki67, and TLR5 were immunohistochemically stained. Final cohort included 45 patients with progressive Barrett's metaplasia (n = 21) or low-grade dysplasia (n = 24), and 92 patients with non-progressive Barrett's metaplasia (n = 52) or low-grade dysplasia (n = 40). In Barrett's metaplasia, aberrant p53 expression was observed in 6% of samples in progressors and 0% in non-progressors. In low-grade dysplasia, aberrant p53 was seen in 56% of samples in progressors and 17% in non-progressors (Odd's ratio 6.7, 95% CI 1.8-24.6). Ki67 or TLR5 showed no association with disease progression. In this matched case-control study, p53 expression associated with a high risk of malignant progression in Barrett's low-grade dysplasia. Routine staining of p53 is indicated in expert confirmed low-grade dysplasia.

Risk of progression in Barrett's esophagus based on diagnoses of general and gastrointestinal pathologists. A retrospective case-control study from Northern and Central Finland.

BACKGROUND: Esophageal adenocarcinoma (EAC) is the sixth leading cause of cancer-related death worldwide. It develops through Barrett's metaplasia - dysplasia sequence. However, the effectiveness of endoscopic surveillance is limited, since diagnosis of low-grade dysplasia (LGD) is known to be challenging for pathologists. Our aim was to compare the risk of Barrett's progression based on diagnoses of general and expert gastrointestinal (GI) pathologists in a population-based cohort. METHODS: A total of 60 patients with non-dysplastic metaplasia (BE) or LGD progressing to high grade dysplasia (HGD) or EAC during follow-up could be identified in the population. For comparison, series representing non-progressive BE (n = 56) and LGD cases (n = 54), matched for age, gender, and length of follow-up were collected. All available original HE stained slides (n = 292) were blindly re-evaluated by two experienced GI pathologists and patient groups of progressive non-progressive BE and LGD were formed according to revised diagnoses. RESULTS: Original diagnosis for each sample was changed in 25% of BE, 59% of LGD, and 33% of HGD diagnoses. Of the original LGD diagnoses, 53% were downgraded to BE or indefinite for dysplasia (ID). Of LGD diagnoses made by an expert GI pathologist, 61% were in the progressive LGD group, whereas only 42% of general pathologists' LGD diagnoses were in the progressive LGD group. CONCLUSION: Based on this retrospective case-control study, LGD is strongly over-diagnosed among general pathologists. LGD diagnosed by expert GI pathologists predicts progressive disease. Recommendation for consensus diagnosis by expert GI pathologists is justified also in the Finnish population-based setting.

A Straightforward Method for Adipocyte Size and Count Analysis Using Open-source Software QuPath.

Changes in adipose tissue morphology, depicted by cell morphology alterations such as enlargement of fat cells, always accompany over-weight and obesity. The variables related to cell size have been shown to associate with low-grade inflammation of adipose tissue and common obesity-related comorbidities including metabolic syndrome and type 2 diabetes. Quantifying fat cell morphology from images of histological specimens can be tedious. Here, we present a straightforward method for the task using the free open-source software QuPath with its inbuilt tools only. Measurements of human adipose tissue samples with the described protocol showed an excellent correlation with those obtained with ImageJ software with Adipocyte Tools plugin combined with manual correction of misdetections. Intraclass correlation between the two methods was at good to excellent level. The method described here can be applied to considerably large tissue areas, even whole-slide analysis.

Carbonic Anhydrases II, IX, and XII in Reflux Esophagitis.

BACKGROUND: The pathogenesis of gastroesophageal reflux disease (GERD) has not been resolved in detail. Esophageal epithelial cells provide resistance to acidic reflux via several mechanisms, many of which involve buffering acid with bicarbonate and transporting protons. Carbonic anhydrases (CAs) are enzymes that control the acid-base balance by catalyzing the reversible hydration of carbon dioxide to produce bicarbonate and hydrogen ions. AIMS: We aimed to determine the immunohistochemical expression patterns of CAII, CAIX, and CAXII in the normal esophageal squamous epithelium and in patients with GERD. METHODS: We evaluated 82 biopsy samples, including 26 with a histologically normal esophagus, 26 with histologically mild esophagitis, and 30 with severe esophagitis. Expression patterns of CAII, CAIX, and CAXII in the esophageal squamous epithelium were determined by immunohistochemical staining. RESULTS: Cytoplasmic CAII expression was predominantly detected in the upper luminal part of the squamous epithelium and was significantly (p < 0.01) increased in GERD. Expression of CAIX was essentially membranous. The isozyme was constantly present in the peripapillary cells. In the interpapillary areas, clustered expression was observed to emerge and increase significantly (p < 0.01) in esophagitis. CAXII expression was the most abundant of the isozymes and was mainly membranous. In the normal squamous epithelium, CAXII expression was confined to the basal layer; in severe esophagitis, CAXII expression increased significantly in both basal (p < 0.05) and superficial (p < 0.01) halves of the epithelium. CONCLUSIONS: We demonstrate upregulated expression of CAII, CAIX, and CAXII in GERD. The increase in expression likely contributes to esophageal epithelial resistance to acidic reflux.

Serological Biomarker Panel in Diagnosis of Atrophic Gastritis and Helicobacter pylori Infection in Gastroscopy Referral Patients: Clinical Validation of the New-Generation GastroPanel® Test.

BACKGROUND/AIM: Prompted by the increasing demand of non-invasive diagnostic tools for screening of gastric cancer (GC) risk conditions, i.e., atrophic gastritis (AG) and Helicobacter pylori (Hp) infection, the GastroPanel® test (GP: biomarker panel of PGI, PGII, G-17, Hp IgG ELISA) that was developed in the early 2000's, was recently updated to a new-generation (unified GP) test version. This clinical validation study evaluated the diagnostic accuracy of the new-generation GP test in detection of AG and Hp among gastroscopy referral patients in a University Clinic. PATIENTS AND METHODS: Altogether, 522 patients were enrolled among the patients referred for gastroscopy at the Gastro Center, Oulu University Hospital (OUH). All patients underwent gastroscopy with biopsies classified using the Updated Sydney System (USS), and blood sampling for GP testing. RESULTS: Biopsy-confirmed AG was found in 10.2% (53/511) of the patients. The overall agreement between the GP and the USS classification was 92.4% (95%CI=90.0-94.6%), with the weighted kappa (κw) of 0.861 (95%CI=0.834-0.883). In ROC analysis using moderate/severe AG of the corpus (AGC2+) as the endpoint, AUC=0.952 (95%CI=0.891-1.000) and AUC=0.998 (95%CI=0.996-1.000) for PGI and PGI/PGII, respectively. Hp IgG antibody ELISA detected biopsy-confirmed Hp-infection with AUC=0.993 (95%CI=0.987-0.999). CONCLUSION: The new generation GastroPanel® is a precise test for non-invasive diagnosis of atrophic gastritis and Hp-infection in dyspeptic patients referred for diagnostic gastroscopy.

Carbonic Anhydrases II and IX in Non-ampullary Duodenal Adenomas and Adenocarcinoma.

Non-ampullary duodenal adenocarcinoma (DAC) is a rare malignancy. Little information is available concerning the histopathological prognostic factors associated with DAC. Carbonic anhydrases (CAs) are metalloenzymes catalyzing the universal reaction of CO2 hydration. Isozymes CAII, CAIX, and CAXII are associated with prognosis in various cancers. Our aim was to analyze the immunohistochemical expressions of CAII, CAIX, and CAXII in normal duodenal epithelium, duodenal adenomas, and adenocarcinoma and their associations with clinicopathological variables and survival. Our retrospective study included all 27 DACs treated in Oulu University Hospital during years 2000-2020. For comparison, samples of 42 non-ampullary adenomas were collected. CAII expression was low in duodenal adenomas and adenocarcinoma. CAIX expression in adenomas and adenocarcinoma was comparable with the high expression of normal duodenal crypts. Expression patterns in carcinomas were largely not related to clinicopathological features. However, low expression of CAII associated with poorer differentiation of the tumor (p=0.049) and low expression of CAIX showed a trend for association with nodal spread, although statistical significance was not reached (p=0.091). CAII and CAIX lost their epithelial polarization and staining intensity in adenomas. CAXII expression was not detected in the studied samples. CAs were not associated with survival. The prognostic value of CAII and CAIX downregulation should be further investigated. Both isozymes may serve as biomarkers of epithelial dysplasia in the duodenum.

Pathophysiology of reflux oesophagitis: role of Toll-like receptors 2 and 4 and Farnesoid X receptor.

The pathogenesis of gastroesophageal reflux disease (GERD) is not fully understood. It involves the activation of mucosal immune-mediated and inflammatory responses. Toll-like receptors (TLR) 2 and TLR4 are pattern-recognition receptors of the innate immune system; they recognize microbial and endogenous ligands. Farnesoid X receptor (FXR) is a bile acid receptor that regulates the inflammatory response. We aimed to evaluate TLR2, TLR4 and FXR expression patterns in GERD. We re-evaluated 84 oesophageal biopsy samples according to the global severity (GS) score, including 26 cases with histologically normal oesophagus, 28 with histologically mild oesophagitis and 30 with severe oesophagitis. We used immunohistochemistry and in situ hybridization to assess the expression patterns of TLR2, TLR4 and FXR in oesophageal squamous cells. Immunohistochemistry showed that nuclear and cytoplasmic TLR2 was expressed predominantly in the basal layer of normal oesophageal epithelium. In oesophagitis, TLR2 expression increased throughout the epithelium, and the superficial expression was significantly more intensive compared to normal epithelium, p <0.01. Nuclear and cytoplasmic TLR4 was expressed throughout the thickness of squamous epithelium, with no change in oesophagitis. FXR was expressed in the nuclei of squamous cells, and the intensity of the expression increased significantly in oesophagitis (p <0.05). FXR expression correlated with basal TLR2. In situ hybridization confirmed the immunohistochemical expression patterns of TLR2 and TLR4. In GERD, TLR2, but not TLR4, expression was upregulated which indicates that innate immunity is activated according to a specific pattern in GERD. FXR expression was increased in GERD and might have a regulatory connection to TLR2.

Differential synovial tissue expression of TLRs in seropositive and seronegative rheumatoid arthritis: A preliminary report.

Toll-like receptors (TLRs) are known to have an important role in triggering the innate immune response and in priming antigen-specific adaptive immunity and inflammation. The differences in synovial tissue expression of the TLRs between seronegative and seropositive rheumatoid arthritis (RA) were examined from 9 seropositive RA, 5 seronegative RA and 4 osteoarthritis (OA) patients. Synovitis status was assessed using Krenn's scoring and TLR 1-9 expression by immunohistochemistry. Tissue citrulline content was analysed by HPLC method. In RA TLR expression was generally higher than in OA. TLR2 expression was higher in both seronegative and seropositive RA compared to OA. TLR 1, 4 and 8 expressions were higher in seropositive RA than in seronegative RA or in OA. For TLRs 3, 5, 6, 7 and 9 local differences of expression were found between groups. TLR 1-9 expression correlated with the synovitis grade. No statistical difference was found in synovial tissue citrulline content between the groups. In seropositive RA, the TLR repertoire in the synovial tissue differs from seronegative RA and could explain differences in disease outcomes. The high expression of protein sensing (TLR1, TLR2 and TLR4) and nucleic acid sensing TLRs (TLR7, TLR8 and TLR9) in the seropositive RA could make the synovium primed for reacting to citrullinated proteins and nucleic acids that could be released to extracellular space in formation of neutrophil extracellular traps. This reactivity could be augmented by Fc receptor activation by anti-citrullinated protein antibody immunocomplexes associated with seropositive RA.

Immune Cell Infiltrate and Prognosis in Gastric Cancer.

PURPOSE: To examine and compare the prognostic value of immune cell score (ICS) and Klintrup-Mäkinen (KM) grade in gastric cancer. METHODS: Gastric adenocarcinoma tissues from samples of 741 patients surgically treated in two hospitals in Finland were assessed for ICS and KM grade. Cox regression with adjustment for confounders provided hazard ratios (HRs) and 95% CIs. Subgroup analyses were performed in intestinal and diffuse type subgroups. The primary outcome was 5-year overall survival. RESULTS: High ICS was associated to longer 5-year survival (adjusted HR 0.70, 95% CI 0.52-0.94), compared to low ICS. The difference was significant in intestinal type subgroup (adjusted HR 0.54, 95% CI 0.36-0.81) but not in diffuse type subgroup (adjusted HR 0.92, 95% CI 0.58-1.46). High KM grade was an independent prognostic factor for longer 5-year overall survival (adjusted HR 0.59, 95% CI 0.45-0.77) in both intestinal (adjusted HR 0.61, 95% CI 0.44-0.85) and diffuse subgroups (adjusted HR 0.52, 95% CI 0.31-0.86). ICS and KM grade were moderately correlated (ρ = 0.425). When both immune cell score and KM grade were included in the regression analysis, only KM grade remained prognostic. CONCLUSIONS: Both ICS and KM grade are prognostic factors in gastric adenocarcinoma, but immunohistochemistry-based ICS might not have additional prognostic value over hematoxylin-eosin-based KM grade.

Cohort profile: gastric cancer in the population-based, Finnish National Esophago-Gastric Cancer Cohort (FINEGO) Study.

PURPOSE: The Finnish National Esophago-Gastric Cancer Cohort (FINEGO) was established with the aim of identifying factors that could contribute to improved outcomes in oesophago-gastric cancer. The aim of this study is to describe the patients with gastric cancer included in FINEGO. PARTICIPANTS: A total of 10 457 patients with gastric cancer or tumour diagnosis in the Finnish Cancer Registry or the Finnish Patient Registry during 1987-2016 were included in the cohort, with follow-up from Causes of Death Registry until 31 December 2016. All of the participants were at least 18 years of age, and had undergone either resectional or endoscopic mucosal surgery with curative or palliative intent. FINDINGS TO DATE: Of the 10 457 patients, 90.1% were identified to have cancer in both cancer and patient registries. In all, the median age was 70 at the time of surgery, 54.5% of the patients were men and 64.4% had no comorbidities. Education data were available for 31.1% of the patients, of whom the majority had had <12 years of formal education. Of the 7798 with cancer staging data available, 41.1% had a local cancer. Adenocarcinoma was the most common (94.2%) histological type. Almost all patients underwent open gastrectomy and 214% in hospitals with annual volume of more than 30 gastrectomies per year. A total of 8561 deaths occurred during the study period, of which 6474 were due to oesophago-gastric cancers. The 5-year survival was 34.6% and 5-year cancer-specific survival was 39.7%. FUTURE PLANS: The data in FINEGO can be currently used for registry-based research but is being expanded by data extraction from patient records and scanning of histological samples from the Finnish biobanks. Initially, we are planning on studies on the national trends in treatment and mortality, and studies on the demographic factors and their influence on survival.

Cohort profile: a nationwide population-based retrospective assessment of oesophageal cancer in the Finnish National Esophago-Gastric Cancer Cohort (FINEGO).

PURPOSE: The Finnish National Esophago-Gastric Cancer Cohort (FINEGO) was established to combine the available registry data with detailed patient information to form a comprehensive, retrospective, population-based research platform of surgically treated oesophageal and gastric cancer in Finland. This cohort profile describes the 2045 surgically treated patients with oesophageal cancer included in the FINEGO cohort. PARTICIPANTS: Registry data were collected from the National Cancer, Patient, Education and Death Registries from 1 January 1987 to 31 December 2016. All patients over 18 years of age, who had either curative surgery, palliative surgery or salvage surgery for primary cancer in the oesophagus are included in this study. FINDINGS TO DATE: 2045 patients had surgery for oesophageal cancer in the selected time period. 67.2% were man, and the majority had only minor comorbidities. The proportions of adenocarcinomas and squamous cell carcinomas were 43.1% and 44.4%, respectively, and 12.5% had other or missing histology. Only about 23% of patients received neoadjuvant therapy. Oesophagectomy was the treatment of choice and most patients were treated at low-volume centres, but median annual hospital volume increased over time. Median overall survival was 23 months, 5-year survival for all patients in the cohort was 32.9% and cancer-specific survival was 36.5%. FUTURE PLANS: Even though Finland only has a population of 5.5 million, surgery for oesophageal carcinoma has not been centralised and therefore previously reported results have mostly been small, single-centre cohorts. Because of FINEGO, we now have a population-based, unselected cohort of surgically treated patients, enabling research on national trends over time regarding oesophageal cancer, including patient characteristics, tumour histology, stage and neoadjuvant treatment, surgical techniques, hospital volumes and patient mortality. Data collection is ongoing, and the cohort will be expanded to include more detailed data from patient records and national biobanks.

Systemic inflammation is associated with circulating cell death released keratin 18 fragments in colorectal cancer.

Systemic inflammation is a stage-independent marker of poor prognosis in colorectal cancer (CRC), activated in a complex, multifactorial process. It has been proposed that one of the main factors driving systemic inflammation may be tumor necrosis. Keratin 18 (KRT18) fragments are released from dead cells and their serum levels are markers for apoptotic and necrotic cell death. In CRC, high KRT18 levels associate with advanced disease, but their relationship with tumor necrosis and systemic inflammation is unknown. In this study, serum total soluble KRT18 (tKRT18) and apoptosis-related, caspase-cleaved fragment (aKRT18) levels were measured preoperatively from 328 CRC patients, and their difference was calculated to assess necrosis related KRT18 (nKRT18) levels. The relationships of these markers with tumor necrosis, clinicopathologic features, systemic inflammation markers (C-reactive protein, albumin, and 13 cytokines), and survival were analyzed. High serum tKRT18, aKRT18, and nKRT18 levels showed association with a higher extent of tumor necrosis, distant metastasis, and increased levels of several markers of systemic inflammation, including CXCL8. High serum tKRT18 (multivariable HR 1.94, 95% CI 1.28-2.95, p = .002) and nKRT18 (multivariable HR 1.87, 95% CI 1.24-2.82, p = .003) levels were associated with poor overall survival independent of potential confounding factors. Our results show that tumor necrosis in CRC contributes to serum levels of KRT18 fragments, and both necrosis and KRT18 levels associate with systemic inflammation. Moreover, we show that serum tKRT18 and nKRT18 levels have independent prognostic value in CRC. Our observations confirm the link between cell death and systemic inflammation.

Putative anoikis-resistant subpopulations in colorectal carcinoma: a marker of adverse prognosis.

Anoikis is a form of apoptosis induced when a cell loses contact with the extracellular matrix (ECM). Anoikis resistance is essential for metastasis formation, yet only detectable by in vitro experiments. We present a method for quantitation of putative anoikis-resistant (AR) subpopulations in colorectal carcinoma (CRC) and evaluate their prognostic significance. We studied 137 CRC cases and identified cell subpopulations with and without stromal or extracellular matrix (ECM) contact with hematoxylin-and-eosin-stained sections and immunohistochemistry for laminin and type IV collagen. Suprabasal cells of micropapillary structures and inner cells of cribriform and solid structures lacked both stromal contact and contact with ECM proteins. Apoptosis rate (M30) was lower in these subpopulations than in the other carcinoma cells, consistent with putative AR subpopulation. We determined the areal density of these subpopulations (number/mm2 tumor tissue), and their high areal density independently indicates low cancer-specific survival. In conclusion, we show evidence that subpopulations of carcinoma cells in micropapillary, cribriform, and solid structures are resistant to anoikis as shown by lack of ECM contact and low apoptosis rate. Abundance of these subpopulations is a new independent indicator of poor prognosis in CRC, consistent with the importance of anoikis resistance in the formation of metastasis.

KRAS and BRAF mutations induce anoikis resistance and characteristic 3D phenotypes in Caco­2 cells.

In a number of types of cancer, anoikis, a form of apoptosis induced by loss of extracellular matrix (ECM) attachment, is disturbed. Anoikis resistance is essential in the formation of metastases. A recent study identified carcinoma cell subpopulations surviving without ECM contact in pathological specimens of colorectal cancer. The occurrence of these subpopulations indicated anoikis resistance. In the present study, it is demonstrated that KRAS and BRAF mutations induce anoikis resistance in colon cancer (Caco­2) cells. In 3D cultures, Caco­2 cells transfected with mutated KRAS or BRAF formed multicellular structures analogous to anoikis­resistant subpopulations in actual carcinomas, and serve as an in vitro model for anoikis resistance. Caco­2 cell lines were constructed, with KRAS or BRAF mutations, using retroviral delivery. The current study investigated anoikis resistance using an Annexin V apoptosis test from suspension cultures. 3D in vitro cultures, which were generated in collagen­matrigel mixtures, were assessed using confocal microscopy. 3D cultures embedded in paraffin were analyzed using conventional histopathology. In suspension cultures, Caco­2 cells with KRAS or BRAF mutations indicated a significantly lower proportion of Annexin positivity than the native Caco­2 cells, indicating that these mutations induce anoikis resistance in Caco­2 cells. 3D cultures displayed native Caco­2 cells forming polarized cysts with a single layer thick epithelium, whereas Caco­2 cells with KRAS or BRAF mutations formed partially filled cystic structures or solid round structures where only the outermost layer was in contact with the ECM. Additionally, KRAS mutations induced reversed polarity to Caco­2 cells along with the emergence of solid growth. The present study demonstrated that KRAS and BRAF mutations induce anoikis resistance in Caco­2 colorectal cancer cells. The growth patterns generated from the KRAS and BRAF mutated cells in 3D cultures revealed a resemblance to the putative anoikis­resistant subpopulations in actual carcinomas, including micropapillary structures and solid tumor cell islands. Additionally, KRAS mutation induced the emergence of inverted polarity. In conclusion, 3D cultures with modified Caco­2 cells serve as a valid in vitro model for anoikis resistance and inverted polarity.

Platelet count, aspirin use, and characteristics of host inflammatory responses in colorectal cancer.

BACKGROUND: Platelets not only contribute to hemostasis but also to the regulation of inflammatory reactions and cancer pathogenesis. We hypothesized that blood platelet count would be associated with systemic inflammation, the densities of tumor infiltrating immune cells, and survival in colorectal cancer (CRC), and these relationships could be altered by aspirin use. METHODS: We measured blood platelet count in a cohort of 356 CRC patients and analyzed its relationships with tumor and patient characteristics including aspirin use, markers of systemic inflammation (modified Glasgow Prognostic Score, mGPS; serum levels of CRP, albumin, and 13 cytokines), blood hemoglobin levels, five types of tumor infiltrating immune cells (CD3, CD8, FoxP3, Neutrophil elastase, mast cell tryptase), and survival. RESULTS: Platelet count inversely correlated with blood hemoglobin levels (p < 0.001) and positively correlated with serum levels of CRP and multiple cytokines including IL-1RA, IL-4, IL-6, IL-7, IL-8, IL-12, IFNγ, and PDGF-BB (p < 0.001 for all), while aspirin use was not associated with the levels of systemic inflammatory markers. High platelet count was also associated with high mGPS (p < 0.001) but did not show statistically significant multivariable adjusted associations with the densities of tumor infiltrating immune cells. Higher platelet counts were observed in higher tumor stage (p < 0.001), but platelet count or aspirin use were not associated with patient survival. CONCLUSIONS: High platelet count is associated with systemic inflammation in CRC. This study could not demonstrate statistically significant associations between platelet count, aspirin use, and the densities of tumor infiltrating immune cells.

Histological assessment of stromal maturity as a prognostic factor in surgically treated gastric adenocarcinoma.

AIMS: Histological assessment of stromal maturity is a potential prognostic factor in colorectal cancer, but its applicability in gastric adenocarcinoma is completely unknown. The aim of this study was to evaluate the feasibility and prognostic significance of assessing stromal maturity in gastric adenocarcinoma. METHODS AND RESULTS: This study was conducted retrospectively in a cohort of 583 gastric adenocarcinoma patients treated surgically in Oulu University Hospital, Finland between 1983 and 2016. The original diagnostic slides were used for assessment of stromal maturity. Patients were divided into mature stroma and immature stroma groups, and stromal maturity was analysed in relation to 5-year and overall survival (OS). The primary outcome of the study was 5-year survival, and the secondary outcome was OS. The kappa-coefficient for interobserver agreement was 0.609. Patients with immature stroma had worse 5-year survival compared to patients with mature stroma [adjusted hazard ratio (HR) = 1.32, 95% confidence interval (CI) = 1.06-1.64]. Stromal maturity was significantly associated with 5-year survival in intestinal-type subgroup (adjusted HR = 0.63, 95% CI = 1.20-2.21), but not in the diffuse-type subgroup (adjusted HR = 1.21, 95% CI = 0.87-1.70). CONCLUSIONS: Stromal maturity is an independent prognostic factor in gastric adenocarcinoma, and it can be analysed with moderate reproducibility.