Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 21, 2015; 21(19): 5901-5909
Published online May 21, 2015. doi: 10.3748/wjg.v21.i19.5901
Prognostic value and clinical correlations of 18-fluorodeoxyglucose metabolism quantifiers in gastric cancer
Kinga Grabinska, Maciej Pelak, Jerzy Wydmanski, Andrzej Tukiendorf, Andrea d’Amico
Kinga Grabinska, Radiotherapy and Chemotherapy I Clinic, Maria Skłodowska-Curie Memorial Institute of Oncology, Gliwice Branch, 44-100 Gliwice, Slaskie, Poland
Maciej Pelak, Jerzy Wydmanski, Department of Radiotherapy, Maria Skłodowska-Curie Memorial Institute of Oncology, Gliwice Branch, 44-100 Gliwice, Slaskie, Poland
Andrzej Tukiendorf, Department of Epidemiology and Silesia Cancer Registry, Maria Skłodowska-Curie Memorial Institute of Oncology, Gliwice Branch, 44-100 Gliwice, Slaskie, Poland
Andrea d’Amico, Department of PET Diagnostics, Maria Skłodowska-Curie Memorial Institute of Oncology, Gliwice Branch, 44-100 Gliwice, Slaskie, Poland
Author contributions: Grabinska K and Pelak M wrote the paper, analyzed the data and organized the figures and tables; Grabinska K colected data; Grabinska K, Pelak M and Wydmanski J designed the research; Tukiendorf A analyzed the data; Wydmanski J and d’Amico A supervised and organized process; all authors critically reviewed the manuscript and approved it.
Supported by National Polish Science Centre, No. 403238140.
Ethics approval: The study was reviewed and approved by The Bioethics Committee of Centre of Oncology-Institute, Gliwice branch (committee number-KB/493-59/09) in accordance with the Helsinki Declaration of 1975, as revised in 2000.
Informed consent: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest: This manuscript has not been published and is not under consideration for publication elsewhere. None of the authors have any study-related conflicts of interest to disclose.
Data sharing: Technical appendix, statistical code, and dataset available from the corresponding author at grabinska.kinga@gmail.com.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Kinga Grabinska, MD, Radiotherapy and Chemotherapy I Clinic, Maria Skłodowska-Curie Memorial Institute of Oncology, Gliwice Branch, Wybrzeza Armii Krajowej 15, 44-101 Gliwice, Śląskie, Poland. grabinska.kinga@gmail.com
Telephone: +48-322-788345 Fax: +48-322-788345
Received: October 22, 2014
Peer-review started: October 27, 2014
First decision: December 11, 2014
Revised: December 29, 2014
Accepted: January 21, 2015
Article in press: January 21, 2015
Published online: May 21, 2015
Processing time: 210 Days and 10.1 Hours
Abstract

AIM: To investigate the correlations of pre-treatment positron emission tomography-computer tomography (PET-CT) metabolic quantifiers with clinical data of unstratified gastric cancer (GC) patients.

METHODS: Forty PET-CT scans utilising 18-fluorodeoxyglucose in patients who received no prior treatment were analysed. Analysis involved measurements of maximum and mean standardised uptake volumes (SUV), coefficient of variation (COV), metabolic tumour volumes and total lesion glycolysis of different thresholds above which the tumor volumes were identified. The threshold values were: SUV absolute value of 2.5, 30% of SUVmax, 40% of SUVmax, and liver uptake-based (marked 2.5, 30, 40 and liv, respectively). Clinical variables such as age, sex, clinical stage, performance index, weight loss, tumor histological type and grade, and CEA and CA19.9 levels were included in survival analysis. Patients received various treatment modalities appropriate to their disease stage and the outcome was defined by time to metastasis (TTM) and overall survival (OS). Clinical and metabolic parameters were evaluated by analysis of variance, receiver operating characteristics, univariate Kaplan-Meier, and multivariate Cox models. P < 0.05 was considered statistically significant.

RESULTS: Significant differences were observed between initially disseminated and non-disseminated patients in mean SUV (6.05 vs 4.13, P = 0.008), TLG2.5 (802 cm3vs 226 cm3; P = 0.031), and TLG30 (436 cm3vs 247 cm3, P = 0.018). Higher COV was associated with poor tumour differentiation (0.47 for G3 vs 0.28 for G1 and G2; P = 0.03). MTV2.5 was positively correlated to patient weight loss (< 5%, 5%-10% and > 10%: 40.4 cm3vs 123.6 cm3vs 181.8 cm3, respectively, P = 0.003). In multivariate Cox analysis, TLG30 was prognostic for OS (HR = 1.001, 95%CI: 1.0009-1.0017; P = 0.047) for the whole group of patients. In the same model yet only including patients without initial disease dissemination TLG30 (HR = 1.009, 95%CI: 1.003-1.014; P = 0.004) and MTV2.5 (HR = 1.02, 95%CI: 1.002-1.036; P = 0.025) were prognostic for OS; for TTM TLG30 was the only significant prognostic variable (HR = 1.006, 95%CI: 1.001-1.012; P = 0.02).

CONCLUSION: PET-CT in GC may represent a valuable diagnostic and prognostic tool that requires further evaluation in highly standardised environments such as randomised clinical trials.

Keywords: Stomach neoplasmas; Positron-emission tomography; 18Fluorodeoxyglucose; Neoplasm staging; Distant metastasis

Core tip: This study is one of the first to investigate the potential use of such a variety of radiotracer quantifiers, demonstrating their ability to differentiate locally advanced and disseminated tumours. This broad analysis can be utilized in clinical use to identify groups of patients with an unfavourable tumour prognosis who could possibly benefit from more aggressive treatment. Our database is being continuously updated and we plan to validate our findings in a larger and more homogeneous cohort.