An invasion front gene expression signature for higher-risk patient selection in stage IIA MSS colon cancer.

Stage II colon cancer (CC) encompasses a heterogeneous group of patients with diverse survival experiences: 87% to 58% 5-year relative survival rates for stages IIA and IIC, respectively. While stage IIA patients are usually spared the adjuvant chemotherapy, some of them relapse and may benefit from it; thus, their timely identification is crucial. Current gene expression signatures did not specifically target this group nor did they find their place in clinical practice. Since processes at invasion front have also been linked to tumor progression, we hypothesize that aside from bulk tumor features, focusing on the invasion front may provide additional clues for this stratification. A retrospective matched case-control collection of 39 stage IIA microsatellite-stable (MSS) untreated CCs was analyzed to identify prognostic gene expression-based signatures. The endpoint was defined as relapse within 5 years vs. no relapse for at least 6 years. From the same tumors, three different classifiers (bulk tumor, invasion front, and constrained baseline on bulk tumor) were developed and their performance estimated. The baseline classifier, while the weakest, was validated in two independent data sets. The best performing signature was based on invasion front profiles [area under the receiver operating curve (AUC) = 0.931 (0.815-1.0)] and contained genes associated with KRAS pathway activation, apical junction complex, and heme metabolism. Its combination with bulk tumor classifier further improved the accuracy of the predictions.

Molecular portraits of colorectal cancer morphological regions.

Heterogeneity of colorectal carcinoma (CRC) represents a major hurdle towards personalized medicine. Efforts based on whole tumor profiling demonstrated that the CRC molecular subtypes were associated with specific tumor morphological patterns representing tumor subregions. We hypothesize that whole-tumor molecular descriptors depend on the morphological heterogeneity with significant impact on current molecular predictors. We investigated intra-tumor heterogeneity by morphology-guided transcriptomics to better understand the links between gene expression and tumor morphology represented by six morphological patterns (morphotypes): complex tubular, desmoplastic, mucinous, papillary, serrated, and solid/trabecular. Whole-transcriptome profiling by microarrays of 202 tumor regions (morphotypes, tumor-adjacent normal tissue, supportive stroma, and matched whole tumors) from 111 stage II-IV CRCs identified morphotype-specific gene expression profiles and molecular programs and differences in their cellular buildup. The proportion of cell types (fibroblasts, epithelial and immune cells) and differentiation of epithelial cells were the main drivers of the observed disparities with activation of EMT and TNF-α signaling in contrast to MYC and E2F targets signaling, defining major gradients of changes at molecular level. Several gene expression-based (including single-cell) classifiers, prognostic and predictive signatures were examined to study their behavior across morphotypes. Most exhibited important morphotype-dependent variability within same tumor sections, with regional predictions often contradicting the whole-tumor classification. The results show that morphotype-based tumor sampling allows the detection of molecular features that would otherwise be distilled in whole tumor profile, while maintaining histopathology context for their interpretation. This represents a practical approach at improving the reproducibility of expression profiling and, by consequence, of gene-based classifiers.

Colorectal Tumour Mucosa Microbiome Is Enriched in Oral Pathogens and Defines Three Subtypes That Correlate with Markers of Tumour Progression.

Long-term dysbiosis of the gut microbiome has a significant impact on colorectal cancer (CRC) progression and explains part of the observed heterogeneity of the disease. Even though the shifts in gut microbiome in the normal-adenoma-carcinoma sequence were described, the landscape of the microbiome within CRC and its associations with clinical variables remain under-explored. We performed 16S rRNA gene sequencing of paired tumour tissue, adjacent visually normal mucosa and stool swabs of 178 patients with stage 0-IV CRC to describe the tumour microbiome and its association with clinical variables. We identified new genera associated either with CRC tumour mucosa or CRC in general. The tumour mucosa was dominated by genera belonging to oral pathogens. Based on the tumour microbiome, we stratified CRC patients into three subtypes, significantly associated with prognostic factors such as tumour grade, sidedness and TNM staging, BRAF mutation and MSI status. We found that the CRC microbiome is strongly correlated with the grade, location and stage, but these associations are dependent on the microbial environment. Our study opens new research avenues in the microbiome CRC biomarker detection of disease progression while identifying its limitations, suggesting the need for combining several sampling sites (e.g., stool and tumour swabs).

68Ga-DOTATOC.

The radiopharmaceutical 68Ga-DOTATOC represents the latest radiopharmaceutical in the diagnosis of a neuroendocrine tumor with somatostatin receptor overexpression. Technological and economic difficulties of preparing and quality control of the radiopharmaceutical limit its use to specialised departments. Background of the department with rich experience with radiopharmaceuticals for positron emission tomography allows handling more difficult 68Ga-radiopharmacy and may increase and improve the care of oncology patients.

Role of the Microbiome in the Formation and Development of Colorectal Cancer.

BACKGROUND: The clinical, histopathological, and molecular characteristics of colorectal cancer vary considerably. Factors associated with the heterogeneity of this disease and with understanding the effects of heterogeneity on disease progression and response to therapy are critical for the better stratification of patients and the development of new therapeutic methods. Although studies have focused mainly on tumor molecular profiling, current molecular predictive and prognostic factors are relevant to specific groups of colorectal cancer patients and are mostly used to predict the applicability of targeted biological agents rather than to predict their benefits. Molecular profiling fails to capture aspects important for tumor growth and aggressiveness, including the tumor microenvironment. The gut microbiome, consisting of specific communities of all commensal, symbiotic, and pathogenic microorganisms, has been shown to have a significant impact on the development of many diseases, including Crohns disease, type II diabetes, and obesity. Recent studies have indicated that long-term dysbiosis of the intestinal microflora can influence the development and progression of colorectal cancer, as well as tumor aggressiveness and response to treatment. CONCLUSION: This review article summarizes current knowledge of the gut microbiome in colorectal cancer, including the various mechanisms by which the gut microbiome affects the intestinal wall, thereby contributing to the development and progression of colorectal cancer. This work was supported by Ministry of Health of the Czech Republic (project AZV 16-31966A), project of Ministry of Education, Youth and Sports of the Czech Republic - NPU I - LO1413 a Ministry of Health of the Czech Republic - RVO (MMCI, 00209805). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 15. 4. 2019 Accepted: 17. 6. 2019.

Circulating T cell subsets are associated with clinical outcome of anti-VEGF-based 1st-line treatment of metastatic colorectal cancer patients: a prospective study with focus on primary tumor sidedness.

BACKGROUND: In a prospective study with long-term follow-up, we analyzed circulating T cell subsets in patients with metastatic colorectal cancer (mCRC) in the context of primary tumor sidedness, KRAS status, and clinical outcome. Our primary goal was to investigate whether baseline levels of circulating T cell subsets serve as a potential biomarker of clinical outcome of mCRC patients treated with an anti-VEGF-based regimen. METHODS: The study group consisted of 36 patients with colorectal adenocarcinoma who started first-line chemotherapy with bevacizumab for metastatic disease. We quantified T cell subsets including Tregs and CD8+ T cells in the peripheral blood prior to therapy initiation. Clinical outcome was evaluated as progression-free survival (PFS), overall survival (OS), and objective response rate (ORR). RESULTS: 1) mCRC patients with KRAS wt tumors had higher proportions of circulating CD8+ cytotoxic T cells among all T cells but also higher measures of T regulatory (Treg) cells such as absolute count and a higher proportion of Tregs in the CD4+ subset. 2) A low proportion of circulating Tregs among CD4+ cells, and a high CD8:Treg ratio at initiation of VEGF-targeting therapy, were associated with favorable clinical outcome. 3) In a subset of patients with primarily right-sided mCRC, superior PFS and OS were observed when the CD8:Treg ratio was high. CONCLUSIONS: The baseline level of circulating immune cells predicts clinical outcome of 1st-line treatment with the anti-VEGF angio/immunomodulatory agent bevacizumab. Circulating immune biomarkers, namely the CD8:Treg ratio, identified patients in the right-sided mCRC subgroup with favorable outcome following treatment with 1st-line anti-VEGF treatment.

Myeloid-derived suppressor cells (MDSCs) in patients with solid tumors: considerations for granulocyte colony-stimulating factor treatment.

Myeloid-derived suppressor cells (MDSCs) have been shown to contribute to tumor escape from host immune surveillance and to cancer progression by production of tumor-promoting soluble factors. Granulocyte colony-stimulating factor (G-CSF) is a principle cytokine controlling granulocyte number. Recombinant human G-CSF (rhG-CSF) has become the main therapeutic agent for the treatment of neutropenia and prophylaxis of febrile neutropenia in cancer patients. However, we show here that rhG-CSF triggers accumulation of granulocytic and monocytic subsets. Consequently, we discuss the pharmacological use of granulopoiesis stimulating factors not only in the context of febrile neutropenia but also from the perspective of MDSC-dependent and MDSC-independent mechanisms of immunosuppression and cancer angiogenesis.

Circulating Myeloid-Derived Suppressor Cell Subsets in Patients with Colorectal Cancer - Exploratory Analysis of Their Biomarker Potential.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) contribute to tumor escape from host immune surveillance and to tumor progression by producing tumor-promoting factors. We focused on clinical and analytical MDSCs-related issues as potential biomarkers and immune regulators involved in tumor progression. PATIENTS AND METHODS: We analyzed 10 patients with advanced colorectal carcinoma (CRC) with (M1 subgroup) or without (M0 subgroup) distant metastases at diagnosis. Peripheral blood was collected at diagnosis prior to treatment and subsequently 12 months after therapy initiation. Using multicolor flow cytometry MDSC subsets were evaluated. Monocytic MDSCs (M-MDSCs) were detected as CD45+ CD11b+ CD33+ HLA-DRlow/ CD14+ CD15-, granulocytic MDSCs (CD33hi PMN-MDSC) were detected as CD45+ CD11b+ CD33hi HLA-DRlow/ CD14 CD15+. For analytical and preanalytical studies, random fresh blood specimens predominantly from cancer patients were analyzed. RESULTS: Levels of circulating M-MDSCs were not associated with metastatic disease within advanced CRC patients. Levels of circulating CD33hi PMN-MDSCs were elevated in patients with distant metastases compared to T3 M0 subgroup. Circulating M-MDSCs increased upon treatment initiation in 9 out of 10 patients. CD33hi PMN-MDSCs substantially dropped upon treatment initiation in 5 out of 10 patients and substantially increased in 2 out of 10 patients. Analytical part showed that absolute and relative counts within each MDSC subset are correlated. Coefficient of variation (CV) for repeatability was 6-11% for M-MDSCs and 25-44% for CD33hi PMN-MDSCs. CV for reproducibility was higher with 8-22% for M-MDSCs and 35-79% for CD33hi PMN-MDSCs demonstrating that delay in measurement of MDSCs in whole blood specimen may distort quantification of circulating MDSC subsets. CONCLUSION: The quantification of MDSC subsets is substantially dependent on the type of specimen examined and its preanalytical processing. Exploratory analysis of M-MDSCs and CD33hi PMN-MDSCs in CRC patients revealed different dynamics of M-MDSC and CD33hi PMN-MDSC subsets in the context anti-cancer treatment. Key words: myeloid-derived suppressor cells - preanalytics - colorectal cancer - flow cytometry - immune monitoring.

Focal necrosis mimicking breast cancer following coronary bypass grafting.

BACKGROUND: Breast cancer can be diagnosed easily in most cases. However, occasionally, we are faced with some conditions that can mimic it. These may include inflammations, benign tumors, cysts, hematomas, or, more rarely, focal necrosis. CASE PRESENTATION: This report presents a case of focal breast necrosis following myocardial revascularization with the left internal mammary artery, which is a very rare condition, with only few cases described in the literature. The necrosis becomes usually apparent a few days or weeks after the surgery and is often coincidental with the dehiscence of sternotomy with necrosis of wound edges. As it mostly affects the skin, it can be easily recognized. Also, our patient developed a dehisced sternotomy shortly after the surgery but there were no obvious objective changes on the breast. The condition was first dominated only by non-specific subjective symptom-pain. Later, a lump in the breast occurred, when the sternotomy had already healed. Moreover, an enlarged lymph node was palpable in the axilla. Because of non-typical symptoms, the condition was suggestive of breast cancer for a relatively long time. The patient had suffered from a very strong pain until she was treated by mastectomy with a good clinical result. CONCLUSIONS: Mammary necrosis following the coronary artery bypass is rare. In most cases, it manifests on the skin shortly after the surgery concurrently with dehisced sternotomy, so it can be easily diagnosed. However, in sporadic cases, the symptoms may occur later and may mimic breast cancer. Our objective is to raise awareness of this rare condition.

Fibrous Dysplasia Presenting as a Cold Spot in 18F-FLT PET/CT Imaging.

Fibrous dysplasia (FD) is a benign bone lesion in which normal bone marrow is replaced by fibro-osseous tissue. The usual high fluorodeoxyglucose (F-FDG) uptake in FD may lead to the misdiagnosis of bone malignancy. Herein, we describe the case of a 42-year old man with histologically verified FD of the pubic bone, which has been subsequently examined during follow-up for rectal cancer, using both F-FDG and fluorothymidine (F-FLT) PET/CT imaging. The FD lesion was characterized by a high uptake of F-FDG (hot spot) but very low uptake of F-FLT (cold spot) as compared with the contralateral unaffected pubic bone.

Efficacy of bevacizumab and chemotherapy in the first-line treatment of metastatic colorectal cancer: broadening KRAS-focused clinical view.

BACKGROUND: The aim of the present retrospective study was to analyze clinical outcome and risk factors associated with treatment outcomes according to KRAS status in patient with metastatic colorectal cancer (mCRC) treated with bevacizumab (bev) plus chemotherapy in the first-line setting. METHODS: We performed observational study on 1622 patients with mCRC treated with bev plus oxaliplatin- or irinotecan-based chemotherapy, and correlated treatment outcomes with KRAS mutation status. The primary endpoint was progression-free survival (PFS) and additionally overall survival (OS). Adverse events of bevacizumab and risk factors including location of metastases were evaluated. RESULTS: Mutation in KRAS was present in 40.6% of mCRC cases. The median PFS in patients with wild-type KRAS (wtKRAS) vs mutant KRAS was 11.5 vs 11.4 months, respectively. The median OS was 30.7 vs 28.4 months (p = 0.312). Patients with KRAS mutation had lung metastases more frequently than wtKRAS individuals (32.0% vs 23.8%; p = 0.001). We observed no difference in clinical outcome between hepatic and extrahepatic metastatic disease. CONCLUSION: KRAS mutation does not interfere with clinical benefit from first-line treatment with bevacizumab plus chemotherapy in mCRC patients.

[Platelets in the pathogenesis of solid tumors]. / Krevní desticky v patogenezia lécbe solidních nádoru

Cancer cells trigger platelet aggregation. Reciprocally, platelet aggregation promotes tumor growth and metastasis. Within the tumor microenvironment, platelet regulates tumor growth via several mechanisms involving stimulation of angiogenesis, inflammation, coagulation, and stabilizing of vessel wall. In circulation, cancer cells coated by platelets can travel to metastatic site protected from intravascular shear forces and from immune surveillance. Finally, platelets facilitate adhesion of tumor cells and formation of the metastatic niche. Platelet-derived microparticles contain growth factors contributing to tumor angiogenesis. On the other hand, platelets can selectively release anti-angiogenic factors in a process connected to tumor dormancy. Therapeutical inhibition of platelet aggregation prevents tumor development in certain tumor types and may contribute to better cancer outcome.

Role of platelet chemokines, PF-4 and CTAP-III, in cancer biology.

With the recent addition of anti-angiogenic agents to cancer treatment, the angiogenesis regulators in platelets are gaining importance. Platelet factor 4 (PF-4/CXCL4) and Connective tissue activating peptide III (CTAP-III) are two platelet-associated chemokines that modulate tumor angiogenesis, inflammation within the tumor microenvironment, and in turn tumor growth. Here, we review the role of PF-4 and CTAP-III in the regulation of tumor angiogenesis; the results of clinical trial using recombinant PF-4 (rPF-4); and the use of PF-4 and CTAP-III as cancer biomarkers.