Association Between Tumor Immune Microenvironment And Clinical Outcomes In Anaplastic Lymphoma Kinase Rearrangement Lung Adenocarcinoma Patients Treated With Crizotinib

Objective:Targeted therapy is the first-line treatment in driven-gene non-small lung cancer(NSCLC).The anaplastic lymphoma kinase(ALK)rearrangements are harbored in 3%–7%of NSCLC,enriched in younger patients with adenocarcinoma and a never or light smoking history.Crizotinib as first-generation ALK tyrosine kinase inhibitor(TKI)is associated with more durable outcomes,less toxicity,and a better quality of life compared with conventional chemotherapy.Programmed death-ligand 1(PD-L1)is a predictive biomarker of response to immunotherapy in lung cancer in general.However,TME to targeted therapy in lung adenocarcinoma(ADC)bearing ALK rearrangement is little known.Here,we presented the correlation between TME and the survival of crizotinib among ALK rearrangement ADC.We further investigated the association between T cell receptor(TCR)diversity and clinical outcome of crizotinib in this retrospective study.Methods:This study retrospectively enrolled 105 ADC patients harboring ALK rearrangement between Jan.2013 to Dec.2020 from Hunan Cancer hospital.TME was investigated by detected the expression of tumor cells PD-L1 and infiltration CD8+T cells from baseline tissue samples.In the formalin fixation and paraffin embedding(FFEP)prior to crizotinib treatment,immunohistochemical(IHC)staining was used with PD-L1(Dako 22C3),and immunofluorescence-based multiplex staining(IF-MS)was applied for CD8,PD-L1 and 4’,6-Diamidino-2-Phenylindole,Dihydrochloride(DAPI).Moreover,the TCR DNA sequencing of baseline peripheral blood was performed for TCR diversity.Results:A total of 105 ADC patients were enrolled in our study,of whom a majority of cases were younger(90.5%),female(55.2%),non-smokers(74.3%),and EML4-ALK rearrangement(45.7%).The median progression-free survival(m PFS)was better in patients with PD-L1 expression<50%(m PFS in PD-L1<50%versus≥50%:12 months versus 6 months,P=0.01).The multivariate analysis showed that brain metastasis(hazard ratio(HR):2.049,95%confidence interval(CI):1.236-3.396,p=0.005),PD-L1>50%(HR:1.911,95%CI:1.124-3.250,p=0.017)and ECOG PS 2-4(HR:2.249,95%CI:1.118-5.366,p=0.025)were independent prognostic factor for poor outcome.IF-MS were applied in 58 cases and revealed a positive correlation between the expression of PD-L1 and CD8,and CD8~+PD-L1~+patients was associated with shorter PFS.TCR DNA sequencing was analyzed in 26 patients,and the patients with more TCR count,higher shannonindex,and lower clonality would perfectly benefit from crizotinib treatment,and the types of ALK rearrangement had little impact on TCR diversity.Conclusions:Pre-treatment PD-L1<50%and TCR diversity are associated with longer PFS,the expression of PD-L1 was positive correlated with CD8 expression and CD8~+PD-L1~+patients had poorly PFS.