The Prognostic Role of the Platelet-Lymphocytes Ratio in Gastric Cancer: A Meta-Analysis
September
The Prognostic Role of the Platelet- Lymphocytes Ratio in Gastric Cancer: A Meta- Analysis
Zhengshui Xu 0 1
Wei Xu 0 1
Hua Cheng 0 1
Wei Shen 0 1
Jiaqi Ying 0 1
Fei Cheng 0 1
Wenji Xu 0 1
0 Department of General Surgery, The Second Affiliated Hospital of Nanchang University , Nanchang, Jiangxi , China
1 Editor: William B. Coleman, University of North Carolina at Chapel Hill School of Medicine , UNITED STATES
Systemic inflammatory parameters, such as the elevator PLR (platelet-lymphocyte ratio), the NLR (neutrophil-lymphocyte ratio) and the platelet count (PLT), have been found to be associated with the prognosis in gastric cancer; however, these results, especially those relating to the PLR, remain inconsistent. So we aimed to evaluate the prognostic role of the PLR in gastric cancer by conducting and presenting the findings of this meta-analysis.
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Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: The authors received no specific funding
for this work.
Competing Interests: The authors have declared
that no competing interests exist.
Background
Methods
Results
We conducted a systematic literature search in PubMed, Embase and the Cochrane Library
to evaluate the prognostic value of the PLR in gastric cancer. The quality of the included
studies was evaluated using the Newcastle Ottawa Quality Assessment Scale (NOS). The
hazard ratio (HR) /Odds Ratio (OR) and its 95% confidence were pooled using a random effects
model. A funnel plot based on overall survival was used to evaluate the publication bias.
It total, 8 studies comprising 4513 patients with gastric cancer met the pre-setting inclusion
criteria. In comparison to the normal PLR, an elevated PLR was correlated with a higher
risk of lymph node metastasis with an OR of 1.50 (95% Cl:1.24±1.82; I2 = 17%) and serosal
invasion (T3 +T4) risk with an OR of 2.01 (95% Cl: 1.49±2.73; I2 = 55%), and an elevated
PLR also increased the advanced stage (III +IV) risk with an OR of 1.99 (95% Cl: 1.60±
2.46; I2 = 28%). An elevated PLR was not a reliable predictor for OS with an HR of 0.99
(95% CI: 0.9±1.1; I2 = 12%).
Conclusions
An elevated PLR was correlated with a higher risk of lymph node metastasis, serosal
invasion and advanced stage (III +IV) risk in gastric cancer; however, the PLR may not act as a
negative predictor for the overall survival of gastric cancer.
Introduction
For many years, gastric cancer (GC) has been one of the most common cancer in the world
and one of the leading causes of death worldwide.[
1
] Some methods, such as computed
tomography, magnetic resonance imaging and endoscopy ultrasonography, can predict the
preoperative tumor stage to some extent, however, it is not precise. Furthermore, these examinations
are prohibitively expensive. In the future, we expect that an ideal marker will be developed to
predict the prognosis of gastric cancer. In fact, there are no ideal predictors that can be reliably
used in the clinic. Therefore, we aim to discover a reliable predictive marker, and our clinicians
and researchers have been making efforts to identify this type of bio-marker. Recently, we may
have had some success, as an increasing number of studies have shown that a systemic
inflammatory response has a relationship with the development and progression of cancer [
2–4
].
Inflammation-based variables, such as the PLT count, the NLR, the PLR, etc., may be predictive
markers for the prognosis of gastric cancers [
5–10
]. Among these markers, the PLR may be the
most controversial [
11,12
]. Recently many studies have been performed to assess its prognostic
value in gastric cancer [
5,6,11,13–16
]. According to their results, the prognostic role of the PLR
remains inconsistent. So we conducted this meta-analysis to evaluate the prognostic role of the
PLR in gastric cancer
Materials and Methods
Literature search
We conducted a systematic literature search in PubMed, Embase and the Cochrane Library.
The search for relevant studies was performed using the following terms: (“platelet-lymphocyte
ratio” or “platelet-to-lymphocyte ratio” or “platelet lymphocyte ratio” or PLR) and (“gastric
cancer” or “gastric adenocarcinoma” or “gastric carcinoma” or “stomach tumor” or “stomach
neoplasms”). A MeSH/Emtree search for “stomach neoplasms” was also performed. (Appendix
1) Three databases were searched from inception to July 20, 2016. We scanned the reference
lists of all studies that had been identified in order to search for other potentially eligible
studies. All articles were assessed independently by two authors according to the eligibility criteria
that we had designed. Articles were independently categorized based on their title and abstract.
When articles could not be categorized based on this information, the full-text was retrieved
and reviewed. Any disagreements or questions were resolved by consulting another author.
According to the Preferred (...truncated)