Prognostic significance of platelet-to-lymphocyte ratio (PLR) in patients with breast cancer treated with neoadjuvant chemotherapy: a meta-analysis

Abstract

ObjectivePlatelet-to-lymphocyte ratio (PLR), known as a key systemic inflammatory parameter, has been proved to be associated with response to neoadjuvant therapy in breast cancer (BC); however, the results remain controversial. This meta-analysis was carried out to evaluate the prognostic values of PLR in patients with BC treated with neoadjuvant chemotherapy (NACT).DesignMeta-analysis.Data sourcesRelevant literature published on the following databases: PubMed, Embase, Web of Science databases and the Cochrane Library.Eligibility criteriaAll studies involving patients with BC treated with NACT and peripheral blood pretreatment PLR recorded were included.Data extraction and synthesisTwo researchers independently extracted and evaluated HR/OR and its 95% CI of survival outcomes, pathological complete response (pCR) rate and clinicopathological parameters.ResultsThe last search was updated to 31 December 2022. A total of 22 studies with 5533 patients with BC treated with NACT were enrolled in the final meta-analysis. Our results demonstrate that elevated PLR value appears to correlate with low pCR rate (HR 0.77, 95% CI 0.67 to 0.88, p<0.001, I2=75.80%, Ph<0.001) and poor prognosis, including overall survival (OS) (HR 1.90, 95% CI 1.39 to 2.59, p<0.001; I2=7.40%, Ph=0.365) and disease-free survival (HR 1.97, 95% CI 1.56 to 2.50, p<0.001; I2=0.0%, Ph=0.460). Furthermore, PLR level was associated with age (OR 0.86, 95% CI 0.79 to 0.93, p<0.001, I2=40.60%, Ph=0.096), menopausal status (OR 0.83, 95% CI 0.76 to 0.90, p<0.001, I2=50.80%, Ph=0.087) and T stage (OR 1.05, 95% CI 1.00 to 1.11, p=0.035; I2=70.30%, Ph=0.005) of patients with BC.ConclusionsThis meta-analysis demonstrated that high PLR was significantly related to the low pCR rate, poor OS and disease-free survival (DFS) of patients with BC treated with NACT. Therefore, PLR can be used as a potential predictor biomarker for the efficacy of NACT in BC.

Platelets favor the outgrowth of established metastases

“…Overexpression of galectin-3 ( Lgals3 ), a known GPVI ligand 59 , in metastatic lungs further supports the implication of GPVI in the TiME remodeling. In addition, recent meta-analyses underpinned the association of high platelets to lymphocytes ratio (PLR) with dismal response to chemotherapy and poor overall survival in clinical settings 67 , 68 . Based on these pieces of evidence, we might speculate that platelets influence metastatic outgrowth by (i) promoting cancer cell proliferation and (ii) rewiring the TiME towards an immunosuppressive one.…”