Efficiency Prediction And Prognostic Evaluation Of Neoadjuvant Chemoimmunotherapy For Potentially Resectable Non-small Cell Lung Cancer

Part One.Efficiency and safety of neoadjuvant chemoimmunotherapy in potentially resectable ⅢA/ⅢB non-small cell lung cancer.Background: The standard treatment for locally advanced(stage Ⅲ)non-small cell lung cancer(NSCLC)is immune consolidation therapy after synchronous or sequential radiotherapy and chemotherapy.The 2-year PFS rate is about 42%.Although it has improved compared to the era of radiotherapy and chemotherapy,the data is still not satisfactory.Surgical options may exist for some locally advanced(ⅢA/ⅢB)nonsmall cell lung cancers(NSCLCs).However,information regarding the effectiveness of neoadjuvant immunotherapy in potentially resectable ⅢA/ⅢB NSCLC is limited.The intent of this investigation is to offer a more favorable alternative for potential resectable stage Ⅲ NSCLC when compared to the standard approach of chemoradiotherapy(CCRT/SCRT)followed by immunotherapy,gain surgical opportunities and improve prognosis for patients.Methods: The prospective study included potentially resectable locally advanced non-small cell lung cancer patients who were planned to receive treatment with Sintilimab combined with nab-paclitaxel and carboplatin in the Oncology Department of the First Hospital of Jilin University from March 2020 to August 2021.Patients were confirmed stage ⅢA/ⅢB with T4 or N2(T4 includes invasion of the mediastinum,pericardium,large blood vessels,main trachea,recurrent laryngeal nerve,esophagus,vertebral body,diaphragm,N2 includes multiple ipsilateral mediastinal lymph node enlargement)according to the eighth edition of IASLC TNM staging for lung cancer.Upon initial diagnosis confirmed by thoracic surgery,radical surgery cannot be performed,but there is a possibility of radical surgery after the application of neoadjuvant therapy.Patients who undergo surgery after neoadjuvant therapy need to complete the surgery within 30-45 days after neoadjuvant therapy.The primary endpoint is the 2-year disease-free survival(DFS)rate,while secondary endpoints include the primary pathological response(MPR)rate,pathological complete response(pCR)rate,objective response rate(ORR),decline rate,and adverse events(AE).The primary endpoint was the 2-year disease-free survival(DFS)rate,with secondary endpoints encompassing rates of major pathological response(MPR)and pathologic complete response(pCR),overall survival(OS),overall response rate(ORR),downstaging rate,and adverse events(AEs).Tumor immune cell infiltrates,identified by immunohistochemistry,was assessed as a biomarker at baseline and after surgery.Results: Among the 30 patients who received neoadjuvant chemoimmunotherapy,20 underwent complete resection.The disease control rate was 96.7%,with an ORR of55% and a downstaging rate of 80%.In the subgroup of 20 patients who underwent surgery,the MPR rate was 65%,and the pCR rate was 40%.The 2-year DFS rate for the surgical group was 75%.ORR is not correlated with MPR rate and DFS.In subgroup analysis,the MPR group demonstrated significantly prolonged DFS compared to the non-MPR group(P<0.01).Among the 30 enrolled patients,21(70%)experienced treatment-related adverse events(TRAEs)during neoadjuvant treatment.Half of these TRAEs were of grade 1 or 2 severity(15 out of 30,50%),encompassing conditions such as alopecia(67%),nausea(47%),and asthenia or fatigue(40%).Immune-related adverse events(ir AEs)of any grade were observed in 9 patients(30%),including 6(20%)at grade 1 or 2.Three patients(10%)experienced grade 3 or higher immune-related AEs,consisting of one case of grade 3 elevated myocardial enzymes,one case of grade 3 interstitial pneumonia,and one case of grade 5 bronchopleural fistula(BPF).Conclusions: Neoadjuvant immunotherapy for potentially resectable ⅢA/ⅢB NSCLC patients markedly enhanced the rate of pathological response and the 2-year DFS.The adverse reactions of neoadjuvant chemoimmunotherapy are tolerable.Therefore,neoadjuvant chemoimmunotherapy is a very promising treatment for potentially resectable ⅢA/ⅢB NSCLC.Part Two.Radiological and pathological remission characteristics of neoadjuvant chemoimmunotherapy for non-small cell lung cancer and the application of ssDECTBackground: Neoadjuvant chemoimmunotherapy can significantly improve the pathological response rate and 2-year DFS rate in patients with potentially resectable stage ⅢA/ⅢB NSCLC.However,in clinical practice,it has been found that there is an inconformity(IC)between radiological and pathological remission rate after neoadjuvant chemoimmunotherapy.This phenomenon is unique to patients treated with neoadjuvant chemoimmunotherapy.It not only affects the judgment of patient efficacy after neoadjuvant chemoimmunotherapy,but more importantly,it greatly affects the choice of surgical timing by clinical doctors after neoadjuvant therapy.Therefore,exploring the characteristics and mechanisms of remission in medical records after neoadjuvant chemoimmunotherapy,identifying the reasons for inconsistent radiological and pathological remission,is crucial for evaluating the efficacy,timing of surgery,and prognosis of neoadjuvant chemoimmunotherapy.At the same time,exploring the mechanisms is beneficial for finding some evaluation methods that better reflect pathological remission rates than lung CT.Methods: A secondary analysis was conducted on 20 patients enrolled in the first part of neoadjuvant chemoimmunotherapy,and patients who achieved imaging disease control(CR/PR/SD)after neoadjuvant chemotherapy during the same period were retrospectively included.All patients underwent radical lobectomy and systemic mediastinal lymph node dissection after neoadjuvant therapy.The main research indicators are the difference in pathologocal and pathological remission(IC=pathological remission rate-radiological remission rate),cell composition analysis of pathological specimens under HE staining,and mean iodine value(ROI)of lesions under single source dual energy computed tomography(ssDECT)scan and normalized iodine concentration(NIC)under aortic standard.The proportion of surviving tumor cells,necrotic components,repair components,and immune cell infiltration components were analyzed.Pathological response characteristics of neoadjuvant chemoimmunotherapy and its relationship with IC were analyzed.Meantime,The fundamental reasons for the difference between neoadjuvant chemoimmunotherapy and chemotherapy was analyzed.The correlation between IC and prognosis,and the value of ssDECT in evaluating pathological response were explored.Result: After neoadjuvant immunotherapy,significant immune killing enhancement and decreased immune suppression performance were observed.70% of neoadjuvant chemoimmunotherapy patients have high/medium IC levels(IC ≥ 40%).After neoadjuvant chemotherapy,all patients had low levels of IC(IC<40%).The main pathological changes were observed within the 30-45 day time window after neoadjuvant immunotherapy are extensive necrosis and repair around and inside the cancer nest,which is also the main reason for the IC between pathological and radiological remission after neoadjuvant immunotherapy.High/medium levels of IC(IC ≥ 40%)were associated with prolonged DFS in patients(P<0.01).Patients who achieved pCR after neoadjuvant chemoimmunotherapy showed a significant decrease in ROI and NIC level on ssDECT scans.The range was between 38% and 46%.These attenuation changes were not related to postoperative pathological components.Conclusion: Compared with neoadjuvant chemotherapy,remission rate of neoadjuvant immunotherapy is severely underestimated by the RECIST criteria due to its unique tumor killing mechanism.Ss DECT plays an auxiliary role in evaluating the efficacy of pCR patients,screening immune beneficiaries,and determining the timing of surgery.Part Three.Analysis of tumor microenvironment and exploration of biomarkers in neoadjuvant chemoimmunotherapy based on immunohistochemistry and ctDNABackground: Neoadjuvant chemoimmunotherapy can significantly improve the pathological response rate and 2-year DFS rate of potentially resectable stage ⅢA/ⅢB NSCLC patients.At the same time,due to its unique tumor killing mechanism,there is a phenomenon of inconformity between the efficacy of conventional imaging evaluation and pathological response rate after treatment.This not only affects the judgment of efficacy after neoadjuvant chemoimmunotherapy,but also affects the selection of surgical timing after neoadjuvant immunotherapy.Therefore,searching for biomarkers is significantly for predicting efficacy and prognosis,screening advantageous populations,avoiding missed surgical opportunities,and predicting recurrence early.Methods: Immunohistochemical analysis was performed on the pathological specimens of 20 patients enrolled in the first part of neoadjuvant chemoimmunotherapy.The detection indicators included CD4,CD8,CD20,CD56,Fox P3,CD86,CD163,and CD11 b.The analysis was done to specimens before chemoimmunotherapy and after surgery.Expressions of biomarkers in immunohistochemical were evaluated based on the staining intensity of each biomarker and the percentage distribution score of positive cells in the tumor area.The final immunohistochemical score(H score)was calculated by multiplying these two scores,Analyze the relationship between immune related indicators and patient prognosis.The tissue samples and blood samples retained before treatment were subjected to NGS sequencing.Plasma ctDNA testing was performed again at 2 year after surgery to analyze the relationship between ctDNA based minimal residual lesions(ctDNA MRD).Analysis between MRD and prognosis were performed.Retrieve the RNA sequencing results of patients before and after immunotherapy in the GEO database,and validate the above results using bioinformatics analysis.Result: After neoadjuvant chemoimmunotherapy,the counts of infiltrating CD4+(T cells),CD8+(T cells),and CD20+(B cells)cells were significantly increased,while the number of infiltrating Fox P3+(Treg cells)cells were significantly decreased.The above differences were statistically significant.There is a statistically significant difference in the H score of CD8 between the MPR group and the non MPR group,not only in the pre-treatment specimens but also in the postoperative specimens.There was a statistically significant difference in the immunohistochemical scores of CD8+T cells between the low IC group(IC<40%)and the medium/high IC group(IC ≥ 40%)before treatment(P<0.01).Pretreatment CD8 overexpression(H score ≥ 3)was significantly correlated with prolonged DFS in patients undergoing neoadjuvant chemoimmunotherapy(P<0.01),and also significantly correlated with remission IC value(P<0.01).The above results have also been validated in the database.Conclusion: Neoadjuvant immunotherapy reshapes the tumor microenvironment,reduces immune suppression,and enhances immune cell attack on tumors.The expression of CD8+T cells before treatment is a biomarker for the prognosis of neoadjuvant chemoimmunotherapy.Patients with extensive infiltration of CD8+T cells before treatment were the main population with inconformity between radiological and pathological remission.It is not suitable to make efficacy evaluation with general CT scan and RECIST.