AUTHOR=Zhou Hongbin , Li Jiuke , Zhang Yiting , Chen Zhewen , Chen Ying , Ye Sa 

TITLE=Platelet–lymphocyte ratio is a prognostic marker in small cell lung cancer—A systemic review and meta-analysis

JOURNAL=Frontiers in Oncology

VOLUME=Volume 12 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.1086742

DOI=10.3389/fonc.2022.1086742

ISSN=2234-943X

ABSTRACT=Aim: To evaluate the relationship between platelet lymphocyte ratio (PLR) and prognosis in small cell lung cancer (SCLC) patients.
Method: Comprehensive search was carried out to collect related studies. Two independent investigators extracted the data of hazard ratio (HR) and 95% confidence interval (CI) for overall survival (OS) or progression free survival (PFS). A random effect model was applied to analyze the effect of different PLR levels on OS and PFS in SCLC patients. Moreover, subgroup analysis was conducted to seek out the source of heterogeneity.
Results: A total of 26 articles containing 5592 SCLC patients were included for this meta-analysis. SCLC patients with high PLR level had shorter OS compared with patients with low PLR level, in both univariate model (HR=1.56, 95% CI 1.28-1.90, p < 0.0001) and multivariate model (HR=1.31, 95% CI 1.08-1.59, p = 0.007). SCLC patients with high PLR level had shorter PFS compared with patients with low PLR level, in univariate model (HR=1.71, 95% CI 1.35-2.16, p < 0.0001), but not in multivariate model (HR=1.17, 95% CI 0.95-1.45, p = 0.14). Subgroup analysis showed high level of PLR shortened OS in some subgroups, including Asian subgroup, younger subgroup, mixed stage subgroup, chemotherapy dominant subgroup, high cut off point subgroup and retrospective subgroup. PLR level did not affect OS in other subgroups.
Conclusion: PLR was a good predictor for prognosis of SCLC patients, especially in patients received chemotherapy dominant treatments and predicting OS.