Interdisciplinary insights into the link between gut microbiome and gastric carcinogenesis-what is currently known?

Currently, gastric cancer is one of the leading death-related cancer globally. The etiopathogenesis of gastric cancer is multifactorial and includes among others dysbiotic alterations of gastric microbiota. Molecular techniques revealed that stomach is not a sterile organ and it is resides with ecosystem of microbes. Due to the fact that the role of Helicobacter pylori infection in development of gastric cancer is established and well-studied, this paper is mainly focused on the role of other bacterial as well as viral and fungal gut microbiota imbalance in gastric carcinogenesis. Notably, not only the composition of gastric microbiota may play an important role in development of gastric cancer, but also its activity. Microbial metabolites, such as short-chain fatty acids, polyamines, N-nitroso compounds, and lactate, may significantly affect gastric carcinogenesis. Therefore, this paper discussed aforementioned aspects with the interdisciplinary insights (regarding also immunological point of view) into the association between gut microbiome and gastric carcinogenesis based on up-to-date studies.

Fluorescence Imaging in Colorectal Surgery: An Updated Review and Future Trends.

Fluorescence imaging in colorectal surgery is considered a novel predominantly intraoperative method of ensuring a greater surgical success. The use of fluorescence is linked to advanced tumor visualization and projection of its lymphatics, both vessels and nodes, which results in a higher chance of achieving a total excision. Additionally, iatrogenic complications prove to be reduced using fluorescence during the surgical excision. The combination of fluorescence and artificial intelligence to better facilitate oncological surgery will soon become an established approach in operating rooms worldwide.

Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations.

BACKGROUND: Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery. PURPOSE, AND RESEARCH DESIGN: Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery. STUDY SAMPLE AND DATA COLLECTION: Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed. CONCLUSIONS: It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future.

Fluorescence Imaging Using Methylene Blue Sentinel Lymph Node Biopsy in Melanoma.

INTRODUCTION: Fluorescence imaging of sentinel node biopsy in melanoma is a novel method. Both indocyanine green (ICG) and methylene blue (MB) have fluorescent properties. The aim of this study was to present, for the first time in a clinical series of patients, the possible usage of MB as a fluorescent dye for sentinel node biopsy during surgery for melanoma. MATERIAL AND METHODS: Twenty patients with skin melanoma, who were candidates for sentinel node biopsy were enrolled in our study. All patients underwent simultaneous use of standard nanocolloid and blue dye. Transcutaneous visualization of the sentinel node, visualization of lymphatic channels as well as sentinel node fluorescent visualization were all measured. We also performed calculations of Signal to Background ratios (SBR). RESULTS: In 15% (3/20) of patients, the fluorescent sentinel node was visible through the skin. The median SBR for the sentinel node visualization by fluorescence was 3.15 (range, 2.7-3.5). Lymphatic channels were visible in lymphatic tissue via fluorescence before visualization by the naked eye in 4 patients (20%). The median SBR ratio was 3.69 (range, 2.7-4.2). Sentinel nodes were visible by fluorescence in 13 cases (65%). The median SBR ratio was 2.49 (range, 1.5-5.7). No factors were found to be associated with fluorescent MB visualization of a sentinel node during biopsy. CONCLUSION: This is the first clinical study presenting the usefulness of fluorescent sentinel node biopsy in melanoma patients using MB as a fluorophore. Further studies are necessary to provide methods for its' clinical implementation.

Human epidermal growth factor receptor 2 (HER2) in advanced gastric cancer: where do we stand?

Gastric cancer is one of the most common malignancy worldwide. In unresectable or metastatic disease, the prognosis is poor and in generally less than a year. HER2 expression remains an important biomarker to lead the addition of trastuzumab to first-line systemic chemotherapy in unresectable or metastatic gastroesophageal adenocarcinoma. To date, a major issue is represented by resistance to trastuzumab developed during treatment, considering the not improved outcomes in this molecular subtype of gastroesophageal adenocarcinoma to other HER2 target strategies. In this review, we summarize the available data on the mechanisms underlying primary and secondary resistance to HER2-targeted therapy and current challenges in the treatment of HER2-positive advanced gastric cancer refractory to trastuzumab. Furthermore, we describe the prognostic value of new non-invasive screening methods, under development novel agents (e.g., HER2 antibody-drug conjugates and bispecific antibodies) and strategies with antitumor activity in early studies.

The unwanted third wheel in the Calot's triangle: Incidence and surgical significance of caterpillar hump of right hepatic artery with a systematic review of the literature.

BACKGROUND: Caterpillar hump of the right hepatic artery is a rare variation increasing the risk of vascular and biliary injuries during hepatobiliary surgery. The aim of this study is to record the cases of the right hepatic artery forming caterpillar hump in a cohort of patients underwent laparoscopic cholecystectomy and to report a review of the literature systematically conducted. METHODS: We reviewed clinical and surgical video data of 230 patients with symptomatic cholelithiasis treated with laparoscopic cholecystectomy between January 2016 and August 2017. A systematic literature search in PubMed, Medline, Cochrane and Ovid databases until 30th June 2017 was also performed in accordance with the PRISMA statement. RESULTS: Our institutional data indicated that 1.3% of 230 patients presented caterpillar hump right hepatic artery. The systematic review included 16 studies reporting data from a total of 498 human cadavers and 579 patients submitted to cholecystectomy. The overall proportion of surgical patients with the caterpillar hump right hepatic artery was 6.9%. CONCLUSIONS: Variations of the cystic artery are not just an anatomical dissertation, assuming a very crucial role in surgical strategies to avoid uncontrolled vascular lesions. A meticulous knowledge of the hepatobiliary triangle in association with all elements of 'Culture of Safety in Cholecystectomy' is mandatory for surgeons facing more than two structures within Calot's triangle.

The Role of Microsatellite Instability in Positive Margin Gastric Cancer Patients.

PURPOSE: A positive resection margin (RM+) is acknowledged as a poor prognostic factor after gastrectomy. Microsatellite instability (MSI-H) gastric cancer has been identified as a subgroup of gastric cancer that may be associated with an improved prognosis. The aim of the study was an analysis of MSI status on patients with margin involvement after gastrectomy and examination of the association between MSI, margin status, and survival outcomes. METHODS: From a large prospectively annotated surgical database we collected clinicopathological and survival data on patients who had undergone a potentially curative resection for gastric cancer. MSI status was assessed using a standard 5-marker quasi-monomorphic mononucleotide repeat panel. Patients who were R+ and either microsatellite stable (MSS) or MSI-H were identified and clinicopathological characteristics and disease specific survival was compared. RESULTS: Three hundred and eighty-six patients were identified; 102 (26.4%) cancers were MSI-H. The proportion of R+ resections was not significantly different in MSS and MSI-H groups. For MSS patients 3-, 5-, and 10-year disease-specific survival rates were 9.1%, 0%, and 0%, respectively; for patients with MSI-H R+ tumors these were 38.5%, 30.8%, and 15.4%, respectively. In Cox analysis MSI-H, female gender, and T ≥3 were significantly associated with survival. CONCLUSIONS: Patients with MSI-H gastric cancer may have long-term survival despite R+ margin status. The molecular division of gastric cancer may be an important step in identifying possible tailored surgical treatments corresponding to clinical and pathological factors.

Familial aggregation of gastric cancer with microsatellite instability.

BACKGROUND: Microsatellite instability (MSI) is currently a new molecular subtype of gastric cancer (GC). About 90% of GC cases appear sporadically. MSI seems to be responsible for both sporadic and familial GC. The aim of this study was to analyze the frequency of MSI in GC with familial history of GC. METHODS: The MSI analysis was conducted using five quasi-monomorphic mononucleotide repeats: BAT-26, BAT-25, NR-24, NR-21 and NR-27. From our database, we analyzed 457 patients in terms of cancer history across family members, particularly focusing on GC. RESULTS: MSI status in patients without familial history of GC was present in 22.1% of the cases, whereas in the patients with familial history of GC it was present in 28% of the cases (p = 0.220). For 1st or 2nd degree family members with GC, MSI was observed in 27.6% and in 30.8%, respectively (p = 0.812). MSI was observed in hereditary gastric cancer (HGC) in 33.3% and in familial gastric cancer (FGC) in 30%. No difference in survival rates was observed between the analyzed groups. CONCLUSIONS: In our publication, we could not find any link between familial background and the MSI status in GC patients. More detailed molecular and genetic analysis of subgroups of these patients is required.

Epitope mapping of a new anti-Tn antibody detecting gastric cancer cells.

Here, we introduce a novel scFv antibody, G2-D11, specific for two adjacent Tn-antigens (GalNAc-Ser/Thr) binding equally to three dimeric forms of the epitope, Ser-Thr, Thr-Thr and Thr-Ser. Compared to other anti-Tn reagents, the binding of G2-D11 is minimally influenced by the peptide structure, which indicates a high degree of carbohydrate epitope dominance and a low influence from the protein backbone. With a high affinity (KDapp = 1.3 × 10-8 M) and no cross-reactivity to either sialyl-Tn epitope or blood group A antigens, scFv G2-D11 is an excellent candidate for a well-defined anti-Tn-antigen reagent. Detailed immunohistochemical evaluation of tissue sections from a cohort of 80 patients with gastric carcinoma showed in all cases positive tumor cells. The observed staining was localized to the cytoplasm and in some cases to the membrane, whereas the surrounding tissue was completely negative demonstrating the usefulness of the novel Tn-antigen binding antibody.

Single Center Experience on Anatomy-and Histopathology-Based Gastric Cancer Molecular Classification.

We analyzed the clinical utility of molecular classification based on anatomical and histological background. The study was conducted on 457 patients treated for gastric cancer with additional information about microsatellite instability status. We divided the patients in three groups of molecular classification based on anatomical and histological background: proximal non-diffused, diffused, and distal non-diffused groups. These groups varied in terms of clinical and pathological factors as well as survival rates. The molecular classification based on anatomical and histological data seems to be a useful tool in a simple classification of gastric cancer.

Targeting VEGFR-2 in Metastatic Gastric Cancer: Results From a Literature-Based Meta-Analysis.

Angiogenesis is a key process in cancer development. We performed a meta-analysis to assess the efficacy and safety of the novel VEGFR-2 inhibitors in patients with metastatic gastric and gastroesophageal junction cancer. A literature-based meta-analysis of randomized controlled trials (RCTs) was undertaken. The primary outcome was the overall survival. The pooled analysis from RCTs on anti-VEGFR-2 inhibitors revealed a significant increase in overall survival (hazard ratio for death: 0.69, 95% confidence interval: 0.55-0.87; p = .002). This study confirms the efficacy of novel anti-VEGFR-2 inhibitors. The future studies of these agents will evaluate alone and in combination with chemotherapy the early line of treatment along with the identification of proper predictive biomarker.

Molecular key to understand the gastric cancer biology in elderly patients-The role of microsatellite instability.

BACKGROUND AND OBJECTIVES: Microsatellite instability (MSI) in gastric cancer (GC) is associated with older age. We present the clinicopathological results of younger and older patients with MSI GC. METHODS: We analyzed 472 patients with GC. MSI analysis was done on fresh frozen tissue using five quasimonomorphic mononucleotide repeats: NR-21, NR-24, NR-27, BAT-25, and BAR-26. Clinical and pathological analysis was performed for different age groups. RESULTS: We observed better survival in elderly MSI GC patients compared to younger patients. The percentage of MSI GC increases gradually with increasing age, accounting for 48% of patients over the age of 85 years. A difference in survival was seen between MSI and MSS groups of patients older than 65 years, while no statistical difference was seen for younger groups. Multivariate analysis revealed that MSI status has a significant prognostic factor in patients aged over 70 years (MSS vs. MSI; HR 1.82, P = 0.013). CONCLUSION: MSI is an important prognostic factor above all in elderly GC patients. It is associated with favorable prognosis and may help in planning different approaches to treatment in this subgroup. J. Surg. Oncol. 2017;115:344-350. © 2016 Wiley Periodicals, Inc.

Strong Prognostic Value of Microsatellite Instability in Intestinal Type Non-cardia Gastric Cancer.

BACKGROUND: The clinical role of microsatellite instability (MSI) in gastric cancer (GC) is controversial. A large series of patients submitted to respective surgery for primary GC with a long follow-up time was evaluated. METHODS: 472 patients with prospectively collected frozen samples of normal mucosa and tumor tissue stored in a biological tissue bank were included. Microsatellite analysis was evaluated using 5 quasi monomorphic mononucleotide repeats (BAT-26, BAT-25, NR-24, NR-21, and NR-27). The presence of MSI in 2 or more loci was classified as MSI-H, whereas all other cases were included in the microsatellite-stable (MSS) group. RESULTS: MSI-H phenotype was found in 111 of 472 patients (23.5%). MSI-H status was related significantly with older age, female gender, non-cardia location, WHO histotype, non-cardia Lauren intestinal type, and less advanced stages. Cancer-related 5-year survival was significantly higher in MSI-H versus MSS group (67.6% vs. 35%, p < 0.001). Stratified analysis revealed a significant impact of MSI on prognosis in non-cardia tumors of intestinal type or tubular/poorly differentiated histology, particularly in stages II and III; multivariate Cox regression analysis confirmed MSS status as a strong predictor of poor prognosis (hazard ratio 2.65, 95% CI 1.56-4.51, p < 0.001) in non-cardia intestinal type. No prognostic value of MSI in the diffuse-mixed type and signet-ring cell/mucinous histotypes was observed. CONCLUSIONS: MSI was confirmed as a significant predictor of long term outcome in a large series of GC with a long follow-up time, but the prognostic value is limited to selected histotypes of non-cardia tumors.

Monoclonal antibodies-based treatment in gastric cancer: current status and future perspectives.

Gastric cancer (GC) is the second leading cause of cancer-related death, and despite having improved treatment modalities over the last decade, for most patients, only modest improvements have been seen in overall survival. Recent progress in understanding the molecular biology of GC and the related signaling pathways offers, from the clinical point of view, promising advances for selected groups of patients. In the past, targeted therapies have significantly impacted the treatment strategy of several common solid tumors such as breast, colorectal, and lung cancers. Unfortunately, translational and clinical research shows fewer encouraging targeted treatments with regards to the GC. To date, only two monoclonal antibodies (mAb), named trastuzumab and ramucirumab, are approved for the treatment of advanced GC, suggesting that in GC, maybe more than in other cancers, effective targeted therapy requires patient selection based on precise predictive molecular biomarkers. The aim of this review is to summarize the available data on the clinical advantages offered by the use of mAbs in the treatment of advanced/metastatic GC. Future perspective is also discussed.

Angiogenesis inhibitors in gastric and gastroesophageal junction cancer.

Despite significant improvements in systemic chemotherapy during the past two decades, the prognosis of patients with advanced gastric and gastroesophageal junction adenocarcinoma remains poor. Because of molecular heterogeneity, it is essential to classify tumors based on the underlying oncogenic pathways and to develop targeted therapies acting on individual tumors. Unfortunately, although a number of molecular targets have been studied, very few of these agents can be used in a clinical setting. In this review, we summarize the available data on anti-angiogenic agents in advanced/metastatic gastric cancer.

Evolution and emerging future of cytoreducxtive surgery and hyperthermic intraperitoneal chemoperfusion in gastric cancer: From treating the incurable to preventing recurrence.

The number of new gastric cancer (GC) cases is decreasing, and these patients have longer survival thanks to new oncological treatments. In advanced GC a common evolution of this neoplasm is peritoneal metastases (PM). In the past this finding meant no chance for cure. However, today, using high quality operations and HIPEC, we are able to increase the number of patients treated with curative intention. New options in the diagnosis of PM, tumour susceptibility for different drugs, importance of quality of life, usage in ascites treatment, diagnostic tools in image-guided surgery, new targeted therapies and analysis of currently ongoing trials are presented together with today's knowledge of HIPEC efficacy in order to evaluate gastric PM. HIPEC is an effective tool in the treatment of selected patients with PM from GC. Together with new diagnostic options such as targeted therapies, HIPEC may improve the prognosis of these patients, not only by treating clinically manifest carcinomatosis, but also in the prophylactic setting, addressing occult peritoneal seeding.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for treatment of ovarian cancer.

Hyperthermic intraperitoneal chemotherapy (HIPEC), a strategy combining maximal cytoreductive surgery and maximal regional chemotherapy, has been applied to treat ovarian cancer resulting in long-term survival rates in selected patients. However, the status of HIPEC in ovarian cancer remains an experimental procedure, given the many variables among the data and trials reviewed, to enable us to derive strong conclusions about its role from this overview. In this review we discuss treatment with HIPEC in patients with ovarian cancer and future prospective of its use in clinical setting. HIPEC is an effective tool in the treatment of selected patients with peritoneal carcinomatosis from ovarian cancer. Unfortunately, due to the lack of randomised trials, the evidence of HIPEC is very limited. Future randomised studies are awaited to define the role and clinical impact of HIPEC in ovarian cancer.

One-year postoperative morbidity associated with near-infrared-guided indocyanine green (ICG) or ICG in conjugation with human serum albumin (ICG:HSA) sentinel lymph node biopsy.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is a standard staging procedure in breast cancer and skin melanoma patients. Radioactive colloid (RC) and blue dye are the routinely used markers for staining. The new dye used in this procedure, indocyanine green (ICG), seems to have true potential in near-infrared-guided SLNB. The aim of this study was to analyze 1-year morbidity after SLNB using RC and ICG or RC and ICG conjugated to human serum albumin (ICG:HSA) in breast cancer and skin melanoma patients. METHODS: Forty-nine patients diagnosed with breast cancer and 10 patients with skin melanoma underwent SLNB using ICG with RC and ICG:HSA with RC. A total of 47 SLNB patients without the need for additional lymphadenectomy were evaluated approximately 1 year (11-13 months) for the presence of tattoo, extremity swelling, nerve dysfunction/pain, range of motion, and stiffness. RESULTS: From the 47 patients examined, long-term morbidity was present in 3 (6.4%). In 1 patient, tattoo persisted for 11 months. Mild lymphedema was seen in 1 patient, and 1 patient exhibited minor functional deficit. CONCLUSIONS: Using ICG or ICG:HSA seems to be safe, and long-term morbidity in SLNB patients is low. However, skin discoloration may appear as it does after the use of blue dye, and an increased number of harvested nodes might be associated with an increased number of iatrogenic lymphedema.

Breast cancer: Actual methods of treatment and future trends.

The recent ten to twenty years have seen a substantial progress in the diagnosis and treatment of breast cancer. A rapid development of various curative options has led to the improvement of treatment outcomes, while paying more and more attention to the aspects of quality of life and cosmetic effect. In our publication, we wish to outline certain trends in the development of modern treatment of breast cancer. Among topics discussed are new forms of molecular diagnostics, new approach to the idea of sentinel node biopsy, as well as new techniques for delivery of medical procedures, the increasing use of nomograms, progress in the techniques of breast conservative treatment, modern approach to occult breast lesions, the increasing use of neoadjuvant treatment and intraoperative radiotherapy.