Preliminary Study On The Relationship Between Clinical Features And CTC In Patients With SCLC

Background and objective:Lung cancer is one of the most common malignant tumor with the highest morbidity and mortality in the world.Small cell lung cancer?SCLC?accounts for 15%-20%of all lung cancer,which is characterized by high aggressiveness and relapse,rapid growth,early metastasis,and poor prognosis.Diagnosis of SCLC at an early stage can benefit its prognosis.Circulating tumor cells?CTC?are tumor cells that get into peripheral blood circulation spontaneously or because of medical operations.Advanced technology of CTC detection and enumeration improves the specificity and sensitivity,thus gaining attention on its clinical application.Studies show a higher rate of detection and larger quantity of CTC in SCLC than any other cancer.Pro-gastrin-releasing peptide?Pro-GRP?is the metabolite of GRP,an important product of SCLC.Studies find Pro-GRP has higher sensitivity and specificity than neuron specific enolase?NSE?.This study is aimed to find preliminary evidence for clinical application of CTC and Pro-GRP in SCLC patients.Methods:Peripheral blood samples and clinical features are collected from17patients with SCLC?SCLC group?,20 patients with NSCLC?NSCLC group?and 20 patients without tumor?comparison group?treated at respiratory department of First Hospital Affiliated to Soochow University from December 2016 to April 2017.The counting of CTC in peripheral blood was detected by CellSearch system.The Pro-GRP serum level was detected by enzyme-linked immunosorbent assay?ELISA?.Explore the relationship between CTC,Pro-GRP and clinical features of SCLC patients respectively.Analyze the correlation between CTC and Pro-GRP or NSE.Explore whether there is a positive correlation between Pro-GRP and NSE.SCLC patients are divided into limited disease?LD-SCLC?and extensive disease?ED-SCLC?according to the U.S.Veterans Hospital and the clinical staging criteria revised by International Association for the Study of Lung Cancer in 1989.NSCLC patients are staged by TNM staging.The Zubrod-ECOG-WHO?ZPS?scoring method was adopted to assess the physical score.Statistical analysis was performed with SPSS 21.0,where P values of<0.05 were considered significant.Pictures and tables were drawn by SPSS 21.0 and Excel 2010.Results:1.The CTC positive rate in SCLC group is 58.82%,while that in comparison group is 0%,the difference is statistically significant?P<0.05?.2.CTC counting is related to SCLC patients'PS score,staging,metastasis and the number of metastatic organs?P<0.05?,but is irrelevant with gender,age and smoking history?P>0.05?.3.The Pro-GRP positive rate in SCLC group is 70.59%,the serum Pro-GRP level in SCLC group is significantly higher than that in NSCLC group,the difference is statistically significant?P<0.05?.4.There is no significant correlation between Pro-GRP level and clinical features of SCLC patients?P>0.05?.5.There are positive correlations between CTC and serum Pro-GRP(R_Pro-GRP=0.592,P_Pro-GRP<0.05),and CTC and serum NSE(R_NSE=0.524,P_NSE<0.05).6.Serum Pro-GRP is positively correlated with NSE?R=0.793,P<0.01?.Conclusions:1.CTCs are highly detectable in peripheral blood of SCLC patients.2.The circulating tumor cell counting is significantly correlated with the stage,distant metastasis and PS scores of SCLC patients,which may indicate the progression of SCLC disease.3.Pro-GRP is an important tumor marker in small cell lung cancer.4.Combined detection of CTC and Pro-GRP may have important clinical value in both diagnosis and evaluation of small cell lung cancer.