Critical Thinking About Study Design on Colon Cancer|Quick homework help

1. What study design was used? (200 words minimum)

2. How did the study design limit the findings of the article? (100 words minimum)

Get your paper done on time by an expert in your field.

Order Now

3. Could a better study design be selected? Why or Why not? (200 words minimum)

4. What other design that can selected that is effective? (200 words minimum)

Please see attached file. Thank you

Differential MIR-21 Expression in Plasma From Mesenteric Versus Peripheral Veins

An Observational Study of Disease-free Survival in Surgically Resected Colon Cancer Patients

z-R
Mariano Monzo, MD, PhD, Francisco Martı́ne

MS Ra

Abbreviations: CRC = colorectal cancer, CT = computed

tomography, DFS = disease-free survival, miRNA = microRNA,

MV = mesenteric vein, PV = peripheral vein.

circulating miR-21 in C ing miRNAs from an ar from a peripheral vein

Editor: Maria Kapritsou. Received: June 18, 2014; revised and accepted: September 5, 2014. From the Molecular Oncology and Embryology Laboratory, Human Anatomy Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona (MM, AN, SS, IM, CM, RT); Department of Medical Oncology and Surgery, Hospital Municipal de Badalona, Badalona, Spain (FM-R, IM, RH). Correspondence: Mariano Monzo, Department of Human Anatomy and

Embryology, School of Medicine, University of Barcelona, Casanovas 143, 08036 Barcelona, Spain (e-mail: mmonzo@ub.edu).

This study was partially supported by a grant from SDCSC (Servei de Donació del Cos a la Ciència). RT is recipient of an APIF (Ajuts de Personal Investigador Predoctoral en Formació) grant from the Uni- versitat de Barcelona. Neither of these funding bodies had a role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manu- script; or decision to submit the manuscript for publication.

The authors have no conflicts of interest to disclose. Copyright # 2015 Wolters Kluwer Health, Inc. All rights reserved. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0, where it is permissible to download, share and reproduce the work in any medium, provided it is properly cited. The work cannot be changed in any way or used commercially. ISSN: 0025-7974 DOI: 10.1097/MD.0000000000000145

Medicine � Volume 94, Number 1, January 2015

Isabel Moren
Alfons Navarro, PhD, Sandra Santasusagna,

Rut Tejero, PhD, and

Abstract: Findings on the role of plasma miR-21 expression in

colorectal cancer are contradictory. Before reaching a peripheral vein

(PV), microRNAs released by the tumor are dispersed throughout the

body. We hypothesized that blood drawn from the mesenteric vein

(MV) near the site of the primary tumor could provide more homo-

geneous information than blood drawn from the PV.

We have analyzed miR-21 expression in matched samples of tumor

tissue, normal tissue, MV plasma, and PV plasma in 57 surgically

resected patients with colon cancer and correlated our findings with

clinical characteristics and disease-free survival (DFS).

miR-21 expression was higher in MV than PV plasma (P¼ 0.014)

and in tumor than in normal tissue (P< 0.001). Patients with high levels

of miR-21 in MV plasma had shorter DFS (P¼ 0.05) than those with

low levels, and those with high levels in both MV and PV plasma had

shorter DFS than all other patients (P¼ 0.01).

Our findings suggest that the primary tumor in colon cancer releases

high concentrations of miR-21 in the MV but that these concentrations

are later diluted in the circulatory system. MV expression of miR-21

may be a stronger prognostic marker than PV expression.

(Medicine 94(1):e145)

, Ismael Macias, MD, Carmen Muñoz, MS,
odenas, MD, PhD, o, MD, PhD,

quel Hernández, MD

INTRODUCTION

C olorectal cancer (CRC) is the third most common type of cancer and the second cause of cancer death worldwide.1

The main prognostic factor for relapse and survival in CRC is disease stage, and patients with stage III disease have a higher risk of relapse than those with stage II. Surgery is the standard treatment for stage I to III, and adjuvant treatment has been shown to be effective in stage III but less so in stage II.2

Prognostic and predictive biomarkers can provide a useful tool for selecting treatment and improving outcome in these patients. The analysis of biomarkers in the plasma or serum of CRC patients is a noninvasive yet effective way to determine prog- nosis, detect occult tumors, and monitor treatment.

MicroRNAs (miRNAs), noncoding RNAs that play a key role in the regulation of mRNA expression, are promising diagnostic and prognostic biomarkers in several cancers.3

Numerous studies have shown that miRNAs are aberrantly expressed during tumor developme