Prognostic Significance Of The Platelet-to-lymphocyte Ratio In Patients With Unresectable Metastatic Colorectal Cancer

ObjectiveColorectal cancer(CRC)is one of the most common malignant tumors.According to the latest global cancer data of GLOBOCAN in 2020,the incidence of CRC is 10.0%,ranking the third among malignant tumors.The death rate was 9.4%,ranking second.The onset of CRC is ocessive,the clinical symptoms are not obvious,about 1/4 to 1/3 of the patients have distant metastasis at the first diagnosis,the clinical prognosis is poor,and the CRC is a serious threat to human health.The prognosis indicators of tumors have always been the focus of research.The prognostic indicators with high sensitivity will help evaluate the risk of recurrence,metastasis and death of the tumor.However,the current research shows that traditional indicators such as carcinoembryonic antigen(CEA)and Carbohydrate Antigen199(CA199)assessment of CRC patients have poor sensitivity.The cell-based and molecular testing indicators represented by cyclic tumor cells(CTC)and minor residue(MRDs)are currently lacking high-level evidence-based.Laboratory indicators,as prognostic prediction factor,have received clinical attention due to convenience and fast.Platelet-to-lymphocyte ratio(PLR),as a potential prognostic indicator of tumors,has received clinical attention.platelet(PLT)is activated by various factors in tumor patients,which contribute to the formation of thrombus induced by the tumor.PLT also releases a number of growth factors,which contribute to the growth,invasion and metastasis of the tumor.In addition,inflammation is one of the characteristics of tumors,and the components of inflammatory response,such as pro-inflammatory cytokines and chemokines,often exist in the tumor microenvironment and play an important role in the occurrence and development of tumors.lymphocyte(Lym),as the representative inflammatory cells,plays an important role in the process of inflammation.Studies have found that PLR has shown clinical value in the prognosis of multiple tumor species,such as lung cancer,gastric cancer and esophageal cancer,as well as in the tumor-free survival rate of patients with early colorectal cancer after radical surgery.In this study,therefore,we are looking for a clinically valuable predictor from conventional laboratory indicators by analyzing the relevance of PLR to the survival of a patient in advanced unresectable Metastatic Colorectal Cancer(mCRC).MethodsA retrospective study was conducted on 1 2 0 patients with advanced unresectable mCRC admitted to the First Affiliated Hospital of Dalian Medical University from January 2015 to January 2 022.Among them,67 were males and 53 were females;Age 24-77 years,median age 6 3 years;The initial treatment regimen bevacizumab(Bev)+chemotherapy was 5 3 cases,cetuximab(Cet)+chemotherapy was 25 cases,and chemotherapy alone was 42 patients.Other general clinical data collected included pre-treatment PLT,pre-treatment Lym count,ECOG score,pathological type,degree of differentiation,primary lesion location,metastatic location,CEA,CA19 9,etc.Follow-up method:The time of the patient’s first chemotherapy was taken as the starting time,and the follow-up data was collected by a combination of electronic medical records and telephone follow-up.Follow-up included tumor markers,chest x-ray,ultrasound,CT,MRI,colonoscopy,progression-free survival(PFS),overall survival(OS),etc.The last follow-up was December 31,2022.Research Methods:The ROC curve in SPSS 25.0 was used to determine the PLR=165.64 cut-off value,and 120 patients were divided into low PLR group and high PLR group.Log-rank test and Kaplan-Meier method were used to perform survival analysis,and the differences of PFS and OS between the two groups were compared.The Cox proportional hazards regression model was used for multivariate prognostic analysis.The χ2 test was used to compare the relationship between PLR and other clinical parameters.All results were statistically significant with P<0.05.Results1.Survival analysis of unresectable mCRC patients in two groups of low PLR and high PLRPFS:the median PFS in the low PLR group was 9 months and the median PFS in the high PLR group was 7 months,and the difference was statistically significant(p<0.05).OS:There was no significant difference between the low PLR group and the high PLR group(p>0.05).2.Multivariate analysis of prognostic risk factors in patients with unresectable mCRCPFS:pretreatment PLR and ECOG scores are independent prognostic factors for PFS in patients with unresectable mCRC(p<0.05).OS:primary location,metastatic location,ECOG score,and initial treatment regimen are independent prognostic factors for OS in patients with unresectable mCRC(p<0.05).3.Correlation analysis of PLR with other clinical parameters before treatmentBefore treatment,PLR was correlated with sex(p<0.05),but not with age,ECOG score,pathological type,degree of differentiation,primary tumor location,and metastatic location(p>0.05).For this result,PLR,PLT,and LYM are further divided into two groups as high and low groups with four points.The relationship between gender and prognosis is analyzed.It is found that when PLT=295 is the boundary,the result is as follows:There was no significant difference between sex and OS when PLT<295(p>0.05).There was a statistically significant association between sex and OS when PLT>295(p<0.05).Conclusion1.Pretreatment PLR is an independent prognostic factor for PFS in patients with unresectable mCRC and can be used as a prognostic indicator,and patients with low PLR have better PFS than patients with high PLR.2.Patients with low pretreatment PLR have a better OS trend than patients with high PLR in unresectable mCRC.3.In patients with unresectable mCRC with low PLT before treatment,female patients have a better OS trend than male patients.4.In patients with unresectable mCRC with high PLT before treatment,the OS of male patients is better than that of female patients.