George Malietzis

Comparison of PubMed, Scopus, Web of Science, and Google Scholar: strengths and weaknesses

The evolution of the electronic age has led to the development of numerous medical databases on the World Wide Web, offering search facilities on a particular subject and the ability to perform citation analysis. We compared the content coverage and practical utility of PubMed, Scopus, Web of Science, and Google Scholar. The official Web pages of the databases were used to extract information on the range of journals covered, search facilities and restrictions, and update frequency. We used the example of a keyword search to evaluate the usefulness of these databases in biomedical information retrieval and a specific published article to evaluate their utility in performing citation analysis. All databases were practical in use and offered numerous search facilities. PubMed and Google Scholar are accessed for free. The keyword search with PubMed offers optimal update frequency and includes online early articles; other databases can rate articles by number of citations, as an index of importance. For citation analysis, Scopus offers about 20% more coverage than Web of Science, whereas Google Scholar offers results of inconsistent accuracy. PubMed remains an optimal tool in biomedical electronic research. Scopus covers a wider journal range, of help both in keyword searching and citation analysis, but it is currently limited to recent articles (published after 1995) compared with Web of Science. Google Scholar, as for the Web in general, can help in the retrieval of even the most obscure information but its use is marred by inadequate, less often updated, citation information.—Falagas, M. E., Pitsouni, E I., Malietzis, G. A., and Pappas, G. Comparison of Pub Med, Scopus, Web of Science, and Google Scholar: strengths and weaknesses. FASEB J. 22, 338–342 (2008)

Is right-sided colon cancer different to left-sided colorectal cancer? – A systematic review

Colorectal cancer (CRC) exhibits differences in incidence, pathogenesis, molecular pathways and outcome depending on the location of the tumor. This review focuses on the latest developments in epidemiological and scientific studies, which have enhanced our understanding on the underlying genetic and immunological differences between the proximal (right-sided) colon and the distal (left-sided) colorectum. The different ways in which environmental risk factors influence the pathogenesis of CRC depending on its location and the variations in surgical and oncological outcomes are also discussed in this review. In the current era of personalized medicine, we aim to reiterate the importance of tumor location in management of CRC and the implication on future clinical and scientific research.

A preoperative neutrophil to lymphocyte ratio of 3 predicts disease-free survival after curative elective colorectal cancer surgery.

Objective:This study aims to determine the role of the neutrophil to lymphocyte ratio (NLR) as a prognostic marker for patients with nonmetastatic colorectal cancer undergoing curative resection. Background:An NLR reflects a systematic inflammatory response, with some evidence suggesting that an elevated preoperative NLR of more than 5.0 is associated with poorer survival in patients with colorectal cancer. Methods:Data from 506 consecutive patients with a diagnosis of nonmetastatic colorectal adenocarcinoma undergoing surgical resection between 2006 and 2011 were included. Receiver operating characteristic curve analysis was used to identify the optimal value for NLR in relation to disease-free and overall survival. Univariate and multivariate Cox regression models were used to determine the role of NLR after stratification by several clinicopathological factors. Patients were followed by a standardized protocol until February 2013. Results:Median follow-up was 45 months [interquartile range, 21–65]. Multivariate Cox regression analysis identified an NLR of more than 3 as an independent prognostic factor for disease-free survival (odds ratio = 2.41; 95% confidence interval = 1.12–5.15; P = 0.024) but not for overall survival (odds ratio = 1.23; 95% confidence interval = 0.80–1.90; P = 0.347). A high NLR was significantly associated with older age, higher T and N stages, the presence of microvascular invasion, low preoperative albumin levels, and higher ASA (American Society of Anesthesiologists) status of the patient. Conclusions:For patients with colorectal cancer, a preoperative NLR of more than 3.0 may be an independent prognostic factor for disease-free survival. Considering this in addition to well-established prognostic variables may improve the processes of identifying patients at higher risk of recurrence who would benefit from adjuvant therapies or more frequent surveillance, thereby providing more personalized cancer care.

Lectin-type oxidized LDL receptor-1 distinguishes population of human polymorphonuclear myeloid-derived suppressor cells in cancer patients

PMN-MDSC in cancer patients can be distinguished from neutrophils by a genomic signature and by expression of the LOX-1 receptor. Stressing myeloid-derived suppressor cells in cancer Immunotherapies for cancer have shown promising results in part because they overcome the suppressive effects of the tumor microenvironment on immune cells. Condamine et al. now report that polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) can be distinguished from neutrophils in the same cancer patient by the expression of the lipid metabolism–related molecule lectin-type oxidized LDL receptor-1 (LOX-1). LOX-1–expressing neutrophils were nearly undetectable in healthy individuals but were found prominently in tumor tissues. Moreover, exposing neutrophils from healthy individuals to endoplasmic reticulum stress resulted in up-regulation of LOX-1 and increased suppressive function. These data support the specific targeting of LOX-1–expressing PMN-MDSC for cancer immunotherapy. Polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are important regulators of immune responses in cancer and have been directly implicated in the promotion of tumor progression. However, the heterogeneity of these cells and the lack of distinct markers hamper the progress in understanding the biology and clinical importance of these cells. Using partial enrichment of PMN-MDSC with gradient centrifugation, we determined that low-density PMN-MDSC and high-density neutrophils from the same cancer patients had a distinct gene profile. The most prominent changes were observed in the expression of genes associated with endoplasmic reticulum (ER) stress. Unexpectedly, low-density lipoprotein (LDL) was one of the most increased regulators, and its receptor oxidized LDL receptor 1 (OLR1) was one of the most overexpressed genes in PMN-MDSC. Lectin-type oxidized LDL receptor-1 (LOX-1) encoded by OLR1 was practically undetectable in neutrophils in peripheral blood of healthy donors, whereas 5 to 15% of total neutrophils in cancer patients and 15 to 50% of neutrophils in tumor tissues were LOX-1+. In contrast to their LOX-1− counterparts, LOX-1+ neutrophils had gene signature, potent immunosuppressive activity, up-regulation of ER stress, and other biochemical characteristics of PMN-MDSCs. Moreover, induction of ER stress in neutrophils from healthy donors up-regulated LOX-1 expression and converted these cells to suppressive PMN-MDSCs. Thus, we identified a specific marker of human PMN-MDSC associated with ER stress and lipid metabolism, which provides new insights into the biology and potential therapeutic targeting of these cells.

A systematic review of enhanced recovery care after colorectal surgery in elderly patients

Enhanced recovery after surgery (ERAS) can decrease complications and reduces hospital stay. Less certain is whether elderly patients can fully adhere to and benefit from ERAS. We aimed to determine the safety, feasibility and efficacy of enhanced recovery after colorectal surgery in patients aged ≥ 65 years old.

Low Muscularity and Myosteatosis Is Related to the Host Systemic Inflammatory Response in Patients Undergoing Surgery for Colorectal Cancer.

Objective:We examined the relationships between computed tomography (CT)–defined skeletal muscle parameters and the systemic inflammatory response (SIR) in patients with operable primary colorectal cancer (CRC). Background:Muscle depletion is characterized by a reduced muscle mass (myopenia) and increased infiltration by inter- and intramuscular fat (myosteatosis). It is recognized as a poor prognostic indicator in patients with cancer, but the underlying factors remain unclear. Methods:A total of 763 patients diagnosed with CRC undergoing elective surgical resection between 2006 and 2013 were included. Image analysis of CT scans was used to calculate Lumbar skeletal muscle index (LSMI), and mean muscle attenuation (MA). The SIR was quantified by the preoperative neutrophil to lymphocyte ratio (NLR) and albumin levels. Correlation and multivariate regression analysis was performed to identify independent relationships between patient SIR and muscle characteristics. Results:Patients with NLR > 3 had significantly lower LSMI and lower MA than those with NLR < 3 [LSMI = 42.07 cm2m−2 vs 44.27 cm2m−2 (P = 0.002) and MA = 30.04 Hounsfield unit (HU) vs 28.36 HU (P = 0.016)]. Multivariate logistic regression analysis showed that high NLR [odds ratio (OR) = 1.78 (95% confidence interval [CI]: 1.29–2.45), P < 0.001] and low albumin [OR = 1.80 (95% CI: 1.17–2.74), P = 0.007] were independent predictors of reduced muscle mass. High NLR was significantly related with a low mean MA and hence myosteatosis [OR = 1.60 (95% CI: 1.03–2.49), P = 0.038]. Conclusions:These results highlight a direct association between myopenia, myosteatosis, and the host SIR in patients with operable CRC. A better understanding of factors that regulate muscle changes such as myopenia and myosteatosis may lead to the development of novel therapies that influence a more metabolically “healthy” skeletal muscle and potentially alter cancer outcomes.

The role of body composition evaluation by computerized tomography in determining colorectal cancer treatment outcomes: A systematic review

BACKGROUND Strong evidence indicates that excessive adipose tissue distribution or reduced muscle influence short-, mid-, and long-term colorectal cancer outcomes. Computerized tomography-based body composition (CTBC) analysis quantifies this in a reproducible parameter. We reviewed the evidence linking computerized tomography (CT) based quantification of BC with short and long-term outcomes in colorectal cancer (CRC). METHODS A systematic review was performed according to PRISMA guidelines. A literature search was performed by two independent reviewers on all studies that included CTBC analysis in patients undergoing treatment for CRC using Medline, EMBASE, Google Scholar, and Cochrane databases. Outcomes of interest included short-term recovery, oncological outcomes, and survival. RESULTS Seventy-five studies were identified; sixteen met the inclusion criteria. None were randomized controlled trials and all were cohort studies of small sample size. Several types of CTBC image analysis software were identified, reporting subcutaneous, visceral and skeletal muscle tissues. Visceral obesity and reduced muscle mass were categorical parameters quantified by CTBC analysis. Due to marked study heterogeneity, quantitative data synthesis was not possible. High visceral adipose tissue and reduced skeletal muscle resulted in poorer short-term recovery (eleven studies), poorer oncological outcomes (six studies), and poorer survival (six studies). CONCLUSIONS CTBC techniques may be linked to outcomes in colorectal cancer patients, however larger studies are required. CTBC based assessment may allow early identification of high-risk patients, allowing early optimisation of patients undergoing cancer treatments.

Influence of body composition profile on outcomes following colorectal cancer surgery.

Muscle depletion is characterized by reduced muscle mass (myopenia), and increased infiltration by intermuscular and intramuscular fat (myosteatosis). This study examined the role of particular body composition profiles as prognostic markers for patients with colorectal cancer undergoing curative resection.

Influence of Surgical Resection of Hepatic Metastases From Gastric Adenocarcinoma on Long-term Survival: Systematic Review and Pooled Analysis.

Objectives:The objectives of this systematic review and pooled analysis were to examine long-term survival, morbidity, and mortality following surgical resection of gastric cancer hepatic metastases and to identify prognostic factors that improve survival. Background:Patients with hepatic metastases from gastric cancer are traditionally treated with palliative chemotherapy. Methods:A systematic literature search was undertaken (1990 to 2015). Publications were included if they studied more than 10 patients undergoing hepatectomy for hepatic metastasis from gastric adenocarcinoma in the absence of peritoneal disease or other distant organ involvement. The primary outcome was the hazard ratio (HR) for overall survival. The influence of liver metastasis related factors; multiple vs single and metachronous vs synchronous upon survival was also assessed. Results:The median number of resections for the 39 studies included was 21 (range 10 to 64). Procedures were associated with a median 30-day morbidity of 24% (0% to 47%) and mortality of 0% (0% to 30%). The median 1-year, 3-year, and 5-year survival were 68%, 31%, and 27%, respectively. Survival was improved in Far Eastern compared with Western studies; 1-year (73% vs 59%), 3-year (34% vs 24.5%), and 5-year (27.3% vs 16.5%). Surgical resection of hepatic metastases was associated with a significantly improved overall survival (HR = 0.50; P < 0.001). Meta-analysis confirmed the additional survival benefit of solitary compared with multiple hepatic metastases (odds ratio = 0.31; P = 0.011). Conclusions:The observed improved survival rates following the resection of hepatic metastasis from gastric adenocarcinoma in selected patients merit a prospective study to formally address the survival benefits and the influence on quality of life of such approach.

Immature myeloid cells directly contribute to skin tumor development by recruiting IL-17–producing CD4+ T cells

Ortiz et al. report the accumulation of immature myeloid cells in skin tissue of patients with inflammatory conditions, which predisposes to the development of cancer.