An Elevated Platelet-to-Lymphocyte Ratio Predicts Poor Prognosis and Clinicopathological Characteristics in Patients with Colorectal Cancer: A Meta-Analysis

Abstract

Background. The aims of this study were to evaluate the clinicopathological and prognostic values of platelet-to-lymphocyte ratio (PLR) in colorectal cancer (CRC). Methods. The PubMed and Embase databases and the references of relevant studies were systematically searched. This study was performed with hazard ratios (HRs) and odd ratios (ORs) with corresponding 95% confidence intervals (CIs) as effect measures. Results. Our results indicated that elevated PLR was associated with poor overall survival (HR = 1.46, 95% CI = 1.23–1.73), disease-free survival (HR = 1.64, 95% CI = 1.17–2.30), cancer-specific survival (HR = 1.30, 95% CI = 1.12–1.51), and recurrence-free survival (HR = 1.38, 95% CI = 1.09–1.74) in CRC. For the clinicopathological characteristics, our results indicated that there were differences in the rate of elevated PLR between stages III/IV and I/II groups (OR = 1.38, 95% CI = 1.01–1.88), pT3/T4 and pT1/T2 groups (OR = 1.82, 95% CI = 1.03–3.20), and poor differentiation and moderate/well differentiation (OR = 2.59, 95% CI = 1.38–4.84). Conclusions. Our results indicated that elevated PLR predicted poor prognosis and clinicopathological characteristics in CRC and PLR is a convenient and low-cost blood-derived prognostic marker for CRC.

Evaluation of the prognostic value of platelet to lymphocyte ratio in patients with hepatocellular carcinoma

“…Fuentes et al reported in their cohort of 112 patients with gastric cancer, that patients stratified as high risk by PLR had worse overall survival (22.6 vs. 42.8 months) (13). In the meta-analysis of patients with colorectal cancer, Huang et al included 17 studies and concluded that elevated PLR was associated with poor overall survival, disease-free survival, as well as higher cancer stage and poor differentiation (7). Recently, the utility of PLR has also been extensively explored in various non-cancerous populations, including patients with acute coronary syndrome, immunoglobulin-resistant Kawasaki disease, premature ovarian insufficiency and acute pancreatitis (24)(25)(26)(27).…”

“…However, it is postulated to be closely related to the cancerinduced systemic inflammatory response, which suppresses recruitment of immunosuppressive cells such as regulatory T cells, leading to tumor progression and metastasis (7,9,28). Thrombocytosis results from megakaryocyte stimulation due to pro-inflammatory mediator secretion from tumor, and promotes tumor progression in several mechanisms (29).…”

“…Evaluation of the prognostic value of platelet to lymphocyte ratio in patients with hepatocellular carcinoma such as platelet-lymphocyte ratio (PLR), neutrophillymphocyte ratio (NLR), C-reactive protein have been proven as valuable prognostic factors in multiple gastrointestinal cancers including pancreatic ductal adenocarcinoma, colorectal cancer and gastric cancer (7,(9)(10)(11)(13)(14)(15)(16). In HCC however, the results were still conflicting regarding the prognostic value of PLR to predict overall survival and the optimal cut-off of PLR remains unclear (11,(17)(18)(19)(20).…”

“…As the worldwide epidemics of obesity continues, the incidence of HCC increases with that of nonalcoholic fatty liver disease, and in contrast to the declining mortality rate seen among other cancer types, death rate of HCC is still on the rise (4-6). As tumor metastasis and recurrence remain the major cause of mortality, there is urgent need for identification of reliable and precise biomarkers to predict prognosis and guide individualized treatment in HCC patients (7,8).…”

“…Currently, an accumulating evidence suggests that systemic inflammation suppresses innate anti-tumor immune system, thus facilitates the initiation, progression and metastasis of cancer (7)(8)(9)(10)(11)(12). Inflammatory biomarkers…”