The tumor promoting roles of erythropoietin/erythropoietin receptor signaling pathway in gastric cancer

A novel hybrid algorithm based on Harris Hawks for tumor feature gene selection

Background

Gene expression data are often used to classify cancer genes. In such high-dimensional datasets, however, only a few feature genes are closely related to tumors. Therefore, it is important to accurately select a subset of feature genes with high contributions to cancer classification.

Methods

In this article, a new three-stage hybrid gene selection method is proposed that combines a variance filter, extremely randomized tree and Harris Hawks (VEH). In the first stage, we evaluated each gene in the dataset through the variance filter and selected the feature genes that meet the variance threshold. In the second stage, we use extremely randomized tree to further eliminate irrelevant genes. Finally, we used the Harris Hawks algorithm to select the gene subset from the previous two stages to obtain the optimal feature gene subset.

Results

We evaluated the proposed method using three different classifiers on eight published microarray gene expression datasets. The results showed a 100% classification accuracy for VEH in gastric cancer, acute lymphoblastic leukemia and ovarian cancer, and an average classification accuracy of 95.33% across a variety of other cancers. Compared with other advanced feature selection algorithms, VEH has obvious advantages when measured by many evaluation criteria.

Anemia Management in the Cancer Patient With CKD and End-Stage Kidney Disease

Anemia is a common medical problem among patients with cancer and chronic kidney disease (CKD). Although anemia in patients with CKD is often treated with iron and erythropoietin-stimulating agents, there are controversies with regard to the use of erythropoietin-stimulating agents in cancer patients. In this article, we review the treatment of anemia in patients with cancer and CKD, in addition to summarizing the current guidelines in treatment of anemia in these patients.

Erythropoiesis and chronic kidney disease-related anemia: From physiology to new therapeutic advancements

Erythropoiesis is triggered by hypoxia and is strictly regulated by hormones, growth factors, cytokines, and vitamins to ensure an adequate oxygen delivery to all body cells. Abnormalities in one or more of these factors may induce different kinds of anemia requiring different treatments. A key player in red blood cell production is erythropoietin. It is a glycoprotein hormone, mainly produced by the kidneys, that promotes erythroid progenitor cell survival and differentiation in the bone marrow and regulates iron metabolism. A deficit in erythropoietin synthesis is the main cause of the normochromic normocytic anemia frequently observed in patients with progressive chronic kidney disease. The present review summarizes the most recent findings about each step of the erythropoietic process, going from the renal oxygen sensing system to the cascade of events induced by erythropoietin through its own receptor in the bone marrow. The paper also describes the new class of drugs designed to stabilize the hypoxia-inducible factor by inhibiting prolyl hydroxylase, with a discussion about their metabolism, disposition, efficacy, and safety. According to many trials, these drugs seem able to simulate tissue hypoxia and then stimulate erythropoiesis in patients affected by renal impairment. In conclusion, the in-depth investigation of all events involved in erythropoiesis is crucial to understand anemia pathophysiology and to identify new therapeutic strategies, in an attempt to overcome the potential side effects of the commonly used erythropoiesis-stimulating agents.

The prognostic role of perioperative allogeneic blood transfusions in gastric cancer patients undergoing curative resection: A systematic review and meta-analysis of non-randomized, adjusted studies

The impact of allogeneic perioperative blood transfusions (APTs) on the prognosis of gastric cancer patients undergoing curative-intent gastrectomy is still a highly debated topic. Two meta-analyses were published in 2015, and new studies report conflicting results. A literature review was conducted using PubMed, Scopus, the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews, updated to March 1, 2016. Thirty-eight non-randomized studies reporting data on overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS) and postoperative complications (PCs) were included. An inverse variance random-effects meta-analysis was conducted. APTs showed an association with worse OS, DFS, DSS and an increased number of PCs. The hazard ratio (HR) for OS was 1.49, with a 95% confidence interval (95% CI) of 1.32-1.69 (p < .00001; Q-test p = .001, I-squared = 56%). After outlier exclusion, the HR for OS was 1.34 (95% CI = 1.23-1.45, p < .00001; Q-test p = .64, I-squared = 0%). The HR for DFS was 1.48 (95% CI = 1.18-1.86, p = .0007; Q-test p = .31, I-squared = 16%), and the HR for DSS was 1.66 (95% CI = 1.5-2.19, p = .0004; Q-test p = .96, I-squared = 0%). The odds ratio for PCs was 3.33 (95% CI = 2.10-5.29, p < .00001; Q-test p = .14, I-squared = 42%). This meta-analysis showed a significant association between transfusions and OS, DFS, DSS and PCs. The quality of the evidence was low. Aggregation, selection and selective reporting bias were detected. The biases shifted the results towards significance. Further studies using accurate adjustment methods are needed. Until such additional studies are performed, caution in administering transfusions and optimization of cancer patient blood management are warranted.

Red blood cell transfusion in surgical cancer patients: Targets, risks, mechanistic understanding and further therapeutic opportunities

Anemia is present in more than half of cancer patients and appears to be an independent prognostic factor of short- and long-term adverse outcomes. It increases in the advanced period of cancer and perioperatively, in patients with solid tumors who undergo surgery. As a result, allogeneic red blood cell (RBC) transfusion is an indispensable treatment in cancer. However, its safety remains controversial, based on several laboratory and clinical data reporting a linkage with increased risk for cancer recurrence, infection and cancer-related mortality. Immunological, inflammatory and thrombotic reactions mediated by the residual leukocytes and platelets, the stored RBCs per se, the biological response modifiers and the plasticizer of the unit may underlie infection and tumor-promoting effects. Although the causality between transfusion and infection has been established, the effects of transfusion on cancer recurrence remain confusing; this is mainly due to the extreme biological heterogeneity that characterizes RBC donations and cancer context. In fact, the functional interplay between donation-associated factors and recipient characteristics, including tumor biology per se, inflammation, infection, coagulation and immune activation state and competence may synergistically and individually define the clinical impact of each transfusion in any given cancer patient. Our understanding of how the potential risk is mediated is important to make RBC transfusion safer and to pave the way for novel, promising and highly personalized strategies for the treatment of anemia in surgical cancer patients.