Comparison On Second-line Regimens And Exploration Of Diagnosis And Chemotherapy Efficacy Related Peptides Of SCLC By Serum Mass Spectrum

Background:Small-cell lung cancer(SCLC) is an aggressive malignancy with a propensity for rapid growth, early metastatic dissemination, and acquired drug resistance. SCLC represents 15% to 20% of all diagnoses of lung cancer and 25% of all deaths of lung cancer. Chemotherapy is the cornerstone of treatment for this disease. Despite being initially exquisitely sensitive to the first-line standard chemotherapy, most patients subsequently relapse, and there is no detection can identify these patients now. Therefore it is important to improve the survival rate of SCLC for early diagnosis and accurate prediction of treatment efficacy. The efficacy of second-line treatments after recurrence or progression is usually poor, and the evidence of a benefit from second-line chemotherapy is limited. Some drugs are recommended by the guidelines, but there are no recommended standard second-line regimens for patients with relapsed/advanced small-cell lung cancer. In recent years, comparative proteomics with the core of mass spectrometry technology is used widely in cancer research, and makes possible on related molecular markers of early diagnosis, efficacy and prognostic judgment. It provides a powerful tool for comprehensive exposition of pathogenesis and transfer mechanism of SCLC.Part one Objective:There are no recommended standard second-line regimens for patients with relapsed/advanced small-cell lung cancer. More regimens are formulated based on experience in clinical. So we conducted this retrospective study in order to compare the efficacy and safety of different second-line treatment regimens. Methods:We totally analyzed 309 patients received second-line treatment in our retrospective study.157 patients received best supportive care(BSC), and the rest 152 patients received second-line chemotherapy. The Kaplan–Meier method survival curves and log-rank test were used to analysis the differences among different groups. The endpoints were objective response rate(ORR), disease control rate(DCR), progression-free survival(PFS), and overall survival(OS). Results:1. Patients administered second-line chemotherapy lived significantly longer, with a total OS from first-line therapy of 11.5 months compared to 6.0 months in patients with best supportive care alone(P<0.001), and the ORR、DCR、PFS and OS of the former(including the sensitive disease and resistance/refractory disease patients) were obviously better than that of the latter.2. The ORR and DCR of the patients who received second-line chemotherapy is 39.5% and 59.2%, respectively. The median PFS and OS from second-line chemotherapy were 3.3 months and 5.3 months. The patients who received second-line chemotherapy were divided by types of second-line regimens. There was no statistically significant difference in ORR or DCR among the four subgroups(P=0.521). The median PFS from second-line chemotherapy of the four subgroups were 4.2 months、3.0 months、3.0 months and 3.0 months, respectively, and there was no statistic difference(P=0.169). The median OS from second-line chemotherapy of the four subgroups were 6.3 months、4.5 months、4.5 months and 5.5 months, respectively, with statistical difference(P=0.035).3. Patients were divided further into sensitive disease and resistance/refractory disease. The sensitive disease patients were from group A(VP-16-based rechallenge) and group B1(CPT-11-based regimen). The ORR of the two groups was 48.6% and 35.3%, and the DCR were 68.6% and 58.8%, respectively. There was no statistically significant difference(P=0.264; P=0.400). The median PFS from second-line chemotherapy of the two groups were 4.0 months and 3.0 months, and the second-line median OS were 6.5 months and 4.5 months. There was no statistic difference(P=0.432; P=0.508). The resistance/refractory disease patients were divided into group B2(CPT-11-based regimen)、group C(PTX/DXL-based regimen) and group D(TPT-based regimen). There was no statistic difference in second-line ORR、DCR and median PFS among the three groups.(P value is 0.521、0.528 and 0.775, respectively); The median OS from second-line chemotherapy of the group D is longer than that of group B2 and group C, with statistical difference(P=0.043; P=0.030).4. Correlation analysis show there is a positive correlation with efficacy of second-line chemotherapy and first-line chemotherapy.5. The differences of gradeⅢ~Ⅳhematologic toxicities among the four subgroups were not statistically different. The incidence of diarrhea in non-hematologic toxicities in Patients who received irinotecan as second-line chemotherapy was higher than other three subgroups(P=0.029). Conclusions:Patients who progressed after the completion of first-line chemotherapy can gain survival benefit. The response and the PFS of the different second-line chemotherapies were similar. The patients who received the TPT-based regimen may gain longer overall survival than other resistance/refractory disease patients. The patients gained good efficacy in first-line chemotherapy may have more possibility to get objective response in second-line chemotherapy. The toxicities of the different chemotherapies were similar, but the incidence of diarrhea was higher in patients who received irinotecan.Part two Objective:This study analyzed differences in the serum peptide levels of patients with SCLC and healthy individuals using matrix-assisted laser desorption/ionization(MALDI)-time-of-flight(TOF)-MS. A SCLC serum polypeptide classification model was then established for early diagnosis and exploring tumor biomarkers. We studied the mass spectrometry analysis of serum specimens of the SCLC patients treated with standard first-line chemotherapy, using MALDI-TOF-MS exploratively, in order to find the predictable protein or polypeptide as the chemotherapy efficacy related biomarkers of SCLC. Methods:1. Eighty cases of untreated SCLC patients serum specimens and eighty cases of healthy human serum specimens were randomly divided into training group and test group in accordance with the ratio of five to three without different general characteristics. The training group, included serum samples from 50 SCLC cases and 50 healthy individuals, was used to establish the diagnosis classification model. The test group for validating the proposed model was composed of 30 SCLC cases and 30 healthy individuals. Peptides were extracted from the samples using magnetic bead-based immobilized Cu2+ ion affinity(MB-IMAC-Cu2+), and their mass spectra fingerprints were obtained using an automated MALDI-TOF-MS system. The MS data from the training group was analyzed using the Clinpro Tool? software(CPT) to identify the individual peptide fragments and find the difference of the two groups. Then the CPT system establish the classification model by using the optimal algorithm. The sensitivity and specificity of the model were verified by blind testing with the test group.2. Serum specimens were obtained from the SCLC patients before the treatment of first-line standard chemotherapy, then the efficacy was evaluated by imaging every two cycles after treatments. 80 serum specimens were obtained from the SCLC patients whose efficacy of first-line chemotherapy was evaluated to CR or PR(set to disease remission group), and 74 serum specimens were obtained from the SCLC patients whose efficacy of first-line chemotherapy was evaluated to PD(set to disease progression group). Then the 154 specimens were randomly divided into training group and test group in accordance with the ratio of five to three. The train group included 50 specimens of disease remission patients and 46 specimens of disease progression patients, which used to establish the classification model. The test group included 30 specimens of disease remission patients and 28 specimens of disease progression patients, which used to verify the accuracy of the classification model. The polypeptides extracted by MB-IMAC-Cu2+ were detected by MALDI-TOF-MS and the group of different peptide were obtained by using the Clin Pro ToolsTM(CPT) software, and the software also built the classification model by using the optimal algorithm. The accuracy of the model were verified by blind testing. Results:(1)In the part one of the study, five peaks of peptides were significantly different in the SCLC samples of the training group, as compared with the controls, and the peptides can used to build the classification model. The mass-to-charge ratio of the peptides were 1021.55Da、1467.31Da、8944.33Da、3139.18 Da and 4137.6Da. Among them, the 8944.33(m/z)、4137.6(m/z) were high expressed in the SCLC patients group, and the 1021.55(m/z)、1467.31(m/z)、3139.18(m/z) were high expressed in the health control group. The blind testing of the model revealed that the sensitivity and the specificity of the proposed method was 96.7%(28/30) and 90.0%(27/30), respectively, and accuracy of the model was 91.7%(55/60).(2)In the part two of the study, four peaks of peptides were significantly different in the SCLC samples of the training group, as compared with the controls, and the peptides can used to build the classification model. The mass-to-charge ratio of the peptides were 3323.35Da、6649.03Da、6451.02Da、4283.18 Da. Among them, the peptides of the mass-to-charge ratio 3323.35Da、6649.03Da、6451.02 Da were high expressed in the SCLC disease remission patients group, and the 4283.18 Da were high expressed in the disease progression patients group. The blind testing of revealed that the total accuracy of the classification model was 94.8%(55/58). At the same time, we conducted the survival analysis between patients who were classified as the disease remission and the patients who were classified as disease progression, in order to identify the ability of prognosis of the model. The Kaplan–Meier method survival curves were used to analysis the differences of the PFS and the OS between the two groups. The median PFS of the twenty-nine SCLC patients who were classified as disease remission was 9.0 months(95%CI: 8.07-9.93) and the median PFS of the twenty-nine SCLC patients who were classified as disease progression was 3.0 months(95%CI: 1.24-4.76); There was statistic difference between the two groups(χ2=46.98,P<0.001). The median OS of the twenty-nine SCLC patients who were classified as disease remission was 13.0 months(95%CI: 12.12-13.88) and the median OS of the twenty-nine SCLC patients who were classified as disease progression was 7.0 months(95%CI: 5.42-8.58), and with statistical difference(χ2=40.64,P<0.001). Conclusions:The date above suggests that the application of the magnetic bead and MALDI-TOF-MS system in the analysis of the serum of the SCLC patients and the healthy people can build the models of SCLC prognostic and chemotherapy efficacy prediction. The small scale blind testing indicated that the models had high sensitivity、specificity and accuracy, and the further survival analysis also suggested the model could preliminarily judge the prognostic of the SCLC patients treated with first-line standard chemotherapy. The methods used in building the models have the superiority of noninvasiveness、convenience、high throughput、high accuracy, and just need small specimens. And the methods have great potential of...