The Prognostic Impact Of The Neutrophil-lymphocyte Ratio And Platelet-lymphocyte Ratio On Patients With Small Cell Lung Cancer

Background: Small cell lung cancer(SCLC) accounts for about 15 percent of all kinds of lung cancer. It has rapid progression, early distant metastasis and poor prognosis. The mean survival time is 2-4 months without treatment. Recently, researchers have found that several clinical indicators have close relationship with the prognosis of the SCLC. Lots of researches have demonstrated that systematic inflammation is related to the outcome of many types of solid tumors. The more serious the inflammation is, the poorer the prognosis is. Many inflammation indexes, such as platelet-lymphocyte ratio(PLR) and neutrophil-lymphocyte ratio(NLR), have been proved to be associated with the prognosis of many kinds of malignant tumor. The current research assessed the association between NLR, PLR and the progression free survival(PFS) in patients who received standard first-line chemotherapy in order to evaluate their application value in terms of predicting prognosis.Methods:We retrospectively reviewed the patients who were diagnosed with SCLC and treated with standard platinum-based chemotherapy more than once from January in 2011 to September in 2015 in Shandong provincial hospital affiliated to Shandong University. Baseline characteristics including gender, age, Eastern Cooperative Oncology Group score, smoking history, disease staging, PFS and the relevant NLR and PLR at diagnosis, after the first chemotherapy and at progression. The optimal cut-off of the NLR and PLR was determined by the time dependent receiver operating curve(ROC) analysis. The time-dependent ROC was performed by using R software 3.30 and SPSS 21.0. The NLR and PLR values were divided into two groups respectively. Survival analysis was performed using Kaplan-Meier method. The differences between two groups were analyzed from different aspects in clinical characteristics. Then the value of PLR and NLR was evaluated in terms of predicting the prognosis of SCLC.Results:In total,82 patients were evaluated.52 were male and 30 were female. The median age is 59 years old (range,26-82 y); 54 of 82 patients had smoking history while 28 patients did not have.53 patients had low ECOG performance status(PS) score(0-l score) and 29 patients had high ECOG PS score.31 people were diagnosed with limited SCLC while the others were diagnosed with extensive SCLC. Time dependent ROC showed that the optimal cut-offs were 2.76 for NLR and 124 for PLR. The patients were categorized into two groups respectively:NLR>2.76 and NLR<2.76; PLR≥124 and PLR<124. The results of survival analysis showed that high NLR and PLR group had shorter PFS(high NLR VS low NLR,5.39 VS 7.47 months, P=0.013; high PLR VS low PLR,5.50 VS 8.37 months, P=0.003). Through analyzing the differences between two groups, the current research found that high NLR and PLR groups had more patients whose disease stages were extensive SCLC at diagnosis.Conclusions:NLR and PLR might be the risk factors influencing the prognosis of SCLC. NLR and PLR are easily acquirable and measurable inflammation indexes. NLR and PLR could play significant roles in predicting the prognosis of SCLC.