Shiyang Kang

Upregulation of PD-L1 by EGFR activation mediates the immune escape in EGFR-driven NSCLC: Implication for optional immune targeted therapy for NSCLC patients with EGFR mutation

Introduction: Epidermal growth factor receptor (EGFR) mutation status was reported to be associated with programmed death-ligand 1 (PD-L1) expression. However, the molecular mechanism of PD-L1 regulation by EGFR activation and the potential clinical significance of blocking PD-1/PD-L1 in EGFR-mutant non–small-cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (TKIs) were largely unknown. Methods: Western blot, real-time polymerase chain reaction, immunofluorescence, and flow cytometry were employed to explore the association between PD-L1 and EGFR activation. Then, we used EGFR-TKIs and downstream pathways inhibitors to clarify the detailed signaling pathway involved in PD-L1 regulation. Cell apoptosis, viability, and enzyme-linked immunosorbent assay test were used to study the immune suppression by EGFR activation and immune reactivation by EGFR-TKIs and/or PD-1 blocking in tumor cells and human peripheral blood mononuclear cells coculture system. Results: We found that EGFR activation by EGF stimulation, exon-19 deletions, and L858R mutation could induce PD-L1 expression. EGFR activation upregulated PD-L1 through p-ERK1/2/p-c-Jun but not through p-AKT/p-S6 pathway. PD-L1 mediated by EGFR activation could induce the apoptosis of T cells through PD-L1/PD-1 axis in tumor cells and peripheral blood mononuclear cells coculture system. Inhibiting EGFR by EGFR-TKIs could free the inhibition of T cells and enhance the production of interferon-&ggr;. Synergistic tumor cell killing effects were not observed with EGFR-TKIs and anti-PD-1 antibody combination treatment in coculture system. Conclusions: Our results imply that EGFR-TKIs could not only directly inhibit tumor cell viability but also indirectly enhance antitumor immunity through the downregulation of PD-L1. Anti-PD-1/PD-L1 antibodies could be an optional therapy for EGFR-TKI sensitive patients, especially for EGFR-TKIs resistant NSCLC patients with EGFR mutation. Combination of EGFR-TKIs and anti-PD-1/PD-L1 antibodies treatment in NSCLC is not supported by the current study but warrant more studies to move into clinical practice.

Patients with Exon 19 Deletion Were Associated with Longer Progression-Free Survival Compared to Those with L858R Mutation after First-Line EGFR-TKIs for Advanced Non-Small Cell Lung Cancer: A Meta-Analysis

Backgrounds It has been extensively proved that the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is superior to that of cytotoxic chemotherapy in advanced non-small cell lung cancer (NSCLC) patients harboring sensitive EGFR mutations. However, the question of whether the efficacy of EGFR-TKIs differs between exon 19 deletion and exon 21 L858R mutation has not been yet statistically answered. Methods Subgroup data on hazard ratio (HR) for progression-free survival (PFS) of correlative studies were extracted and synthesized based on random-effect model. Comparison of outcomes between specific mutations was estimated through indirect and direct methods, respectively. Results A total of 13 studies of advanced NSCLC patients with either 19 or 21 exon alteration receiving first-line EGFR-TKIs were included. Based on the data from six clinical trials for indirect meta-analysis, the pooled HRTKI/chemotherapy for PFS were 0.28 (95% CI 0.20–0.38, P<0.001) in patients with 19 exon deletion and 0.47 (95% CI 0.35–0.64, P<0.001) in those with exon 21 L858R mutation. Indirect comparison revealed that the patients with exon 19 deletion had longer PFS than those with exon 21 L858R mutation (HR19 exon deletion/exon 21 L858R mutation  = 0.59, 95% CI 0.38–0.92; P = 0.019). Additionally, direct meta-analysis showed similar result (HR19 exon deletion/exon 21 L858R mutation  = 0.75, 95% CI 0.65 to 0.85; P<0.001) by incorporating another seven studies. Conclusions For advanced NSCLC patients, exon 19 deletion might be associated with longer PFS compared to L858 mutation at exon 21 after first-line EGFR-TKIs.

Prognostic Significance of Programmed Cell Death 1 (PD-1) or PD-1 Ligand 1 (PD-L1) Expression in Epithelial-Originated Cancer: A Meta-Analysis

AbstractThe expression of programmed cell death 1 (PD-1) and its ligand (PD-L1) has been observed in various epithelial-originated malignancies. However, whether the expression of PD-L1 on tumor cells or the expression of PD-1 on tumor-infiltrating lymphocytes (TILs) is associated with patients’ survival remains controversial.Electronic databases were searched for eligible literatures. Data of hazard ratio (HR) for overall survival (OS) with 95% confidence interval (CI) according to the expression status of PD-L1 or PD-1 evaluated by immunohistochemistry were extracted. The outcomes were synthesized based on random-effects model. Subgroup analyses were proposed.Twenty-nine studies covering 12 types of epithelial-originated malignancies involving 7319 patients (2030/3641 cases for PD-L1 positive/negative, 505/1143 cases for PD-1 positive/negative) with available data of the outcome stratified by PD-L1/PD-1 status were enrolled. Epithelial-originated cancer patients with positive expression of PD-L1 on tumor tissues were associated with significantly poorer OS when compared to those with negative expression of PD-L1 (HR 1.81, 95% CI 1.33–2.46, P < 0.001). Similarly, patients with PD-1 positive expression on TILs had significantly shorter OS than the PD-1 negative group (HR 2.53, 95% CI 1.22–5.21, P = 0.012). In analyses of PD-L1, all subgroups showed consistent trends toward unfavorable prognoses of patients with positive PD-L1 expression, regardless of antibodies and evaluation cutoffs. Subgroup analyses on PD-1 were not available due to limited data.PD-L1 or PD-1 expression status is a significant prognostic factor in epithelial-originated malignancies.

Upregulation of PD-L1 by EML4-ALK fusion protein mediates the immune escape in ALK positive NSCLC: Implication for optional anti-PD-1/PD-L1 immune therapy for ALK-TKIs sensitive and resistant NSCLC patients

ABSTRACT Driver mutations were reported to upregulate programmed death-ligand 1 (PD-L1) expression. However, how PD-L1 expression and immune function was affected by ALK-TKIs and anti-PD-1/PD-L1 treatment in ALK positive non-small-cell lung cancer (NSCLC) remains poorly understood. In the present study, western-blot, real-time PCR, flow cytometry and immunofluorescence were employed to explore how PD-L1 was regulated by ALK fusion protein. ALK-TKIs and relevant inhibitors were used to identify the downstream signaling pathways involved in PD-L1 regulation. Cell apoptosis, viability and Elisa test were used to study the immune suppression by ALK activation and immune reactivation by ALK-TKIs and/or PD-1 blocking in tumor cells and DC-CIK cells co-culture system. We found that PD-L1 expression was associated with EGFR mutations and ALK fusion genes in NSCLC cell lines. Over-expression of ALK fusion protein increased PD-L1 expression. PD-L1 mediated by ALK fusion protein increased the apoptosis of T cells in tumor cells and DC-CIK cells co-culture system. Inhibiting ALK by sensitive TKIs could enhance the production of IFNγ. Anti-PD-1 antibody was effective in both crizotinib sensitive and resistant NSCLC cells. Synergistic tumor killing effects were not observed with ALK-TKIs and anti-PD-1 antibody combination in co-culture system. ALK-TKIs not only directly inhibited tumor viability but also indirectly enhanced the antitumor immunity via the downregulation of PD-L1. Anti-PD-1/PD-L1 antibodies could be an optional therapy for crizotinib sensitive, especially crizotinib resistant NSCLC patients with ALK fusion gene. Combination of ALK-TKIs and anti-PD-1/PD-L1 antibodies treatment for ALK positive NSCLC warrants more data before moving into clinical practice.

Evaluation of the efficacy and safety of anti-PD-1 and anti-PD-L1 antibody in the treatment of non-small cell lung cancer (NSCLC): a meta-analysis

BACKGROUND Currently, blockade of the programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) signaling pathway has been proved one of the most promising immunotherapeutic strategies against cancer. Several antibodies have been developed to either block the PD-1 or its ligand PD-L1 are under development. So far, a series of phase I trials on PD-1/PD-L1 antibodies for non-small cell lung cancer (NSCLC) have been completed, without reports of results from phase II studies. Thus, we sought to perform a meta-analysis incorporating all available evidences to evaluate the efficacy and safety of PD-1 or PD-L1 inhibition therapy. METHODS Electronic databases were searched for eligible literatures. Data of objective respond rate (ORR) and rate of adverse effects (AEs) with 95% confidence interval (CI) evaluated by immunohistochemistry (IHC) was extracted. The outcomes were synthesized based on random-effect model. Subgroup analyses were proposed. RESULTS In overall, ORR in the whole population with PD-1 blockage treatment is 22.5% (95% CI: 17.6% to 28.2%). Additionally, the rate of Grade 3-4 AEs is 16.7% (95% CI: 6.5% to 36.8%) and drug-related death rate is 2.5% (95% CI: 1.3% to 4.6%). As for patients with PD-L1 inhibition therapy, an overall ORR is 19.5% (95% CI: 13.2% to 27.7%). A higher rate of Grade 3-4 AEs (31.7%, 95% CI: 14.2% to 56.5%) is observed with a lower drug-related death rate (1.8%, 95% CI: 0.4% to 8.3%). In exploratory analyses of anti-PD-1 agents, we observed that greater ORR was presented in the median-dose cohort (3 mg/kg) than that of both low-dose (1 mg/kg) and high-dose (10 mg/kg) cohort (low-dose vs. median-dose: OR =0.12, P=0.0002; median-dose vs. high-dose: OR =1.47, P=0.18). CONCLUSIONS Anti-PD-1 and anti PD-L1 antibodies showed objective responses in approximately one fourth NSCLC patients with a tolerable adverse-effect profile. In addition, median-dose (3 mg/kg) might be a preferential dosage of anti-PD-1 agents.

Multi-Targeted Antiangiogenic Tyrosine Kinase Inhibitors in Advanced Non-Small Cell Lung Cancer: Meta-Analyses of 20 Randomized Controlled Trials and Subgroup Analyses

Background Multi-targeted antiangiogenic tyrosine kinase inhibitors (MATKIs) have been studied in many randomized controlled trials (RCTs) for treatment of advanced non-small cell lung cancer (NSCLC). We seek to summarize the most up-to-date evidences and perform a timely meta-analysis. Methods Electronic databases were searched for eligible studies. We defined the experimental arm as MATKI-containing group and the control arm as MATKI-free group. The extracted data on objective response rates (ORR), disease control rates (DCR), progression-free survival (PFS) and overall survival (OS) were pooled. Subgroup and sensitivity analyses were conducted. Results Twenty phase II/III RCTs that involved a total of 10834 participants were included. Overall, MATKI-containing group was associated with significant superior ORR (OR 1.29, 95% CI 1.08 to 1.55, P = 0.006) and prolonged PFS (HR 0.83, 0.78 to 0.90, P = 0.005) compared to the MATKI-free group. However, no significant improvements in DCR (OR 1.08, 1.00 to 1.17, P = 0.054) or OS (HR 0.97, 0.93 to 1.01, P = 0.106) were observed. Subgroup analyses showed that the benefits were predominantly presented in pooled results of studies enrolling previously-treated patients, studies not limiting to enroll non-squamous NSCLC, and studies using MATKIs in combination with the control regimens as experimental therapies. Conclusions This up-to-date meta-analysis showed that MATKIs did increase ORR and prolong PFS, with no significant improvement in DCR and OS. The advantages of MATKIs were most prominent in patients who received a MATKI in combination with standard treatments and in patients who had previously experienced chemotherapy. We suggest further discussion as to the inclusion criteria of future studies on MATKIs regarding histology.

The Efficacy of Combining Antiangiogenic Agents with Chemotherapy for Patients with Advanced Non-Small Cell Lung Cancer Who Failed First-Line Chemotherapy: A Systematic Review and Meta-Analysis

Background The clinical outcomes of patients with NSCLC who progressed after first-line treatments remain poor. The purpose of this study was to assess the advantage of antiangiogenic therapy plus standard treatment versus standard treatment alone for this population of patients. Methods We conducted a rigorous search using electronic databases for eligible studies reporting antiangiogenic therapy combined with standard second-line chemotherapy versus standard second-line treatment for patient who progressed after front-line treatment. Pooled risk ratio and 95% confidence intervals were calculated using proper statistical method. Predefined subgroup analyses were conducted to identify the potential proper patients. Results Thirteen phase II/III RCTs which involved a total of 8358 participants were included. Overall, there was significant improvement in OS (HR 0.94, 95%CI: 0.89-0.99, p=0.03), PFS (HR 0.80, 95%CI: 0.76-0.84, p<0.00001), ORR (RR 1.75, 95%CI: 1.55-1.98, p<0.00001) and DCR (RR 1.23, 95%CI: 1.18-1.28, p<0.00001) in the group with antiangiogenic therapy plus standard treatment versus the group with standard treatment alone. Subgroup analysis showed that OS benefit was presented only in patients treated with docetaxel plus antiangiogenic agents (HR 0.92, 95%CI: 0.86-0.99, p=0.02) and patients with non-squamous NSCLC (HR for OS 0.92, 95%CI: 0.86-0.99, p=0.02). Conclusions This study revealed that the addition of antiangiogenic agents to the standard treatments could provide clinical benefit to NSCLC patients who failed their first-line therapy. Furthermore, proper selection of the combined standard cytotoxic agent, as well as the patient population by tumor histology, is warranted for future studies and clinical application of antiangiogenic therapy.

Development and validation of a nomogram for predicting the survival of patients with non-metastatic nasopharyngeal carcinoma after curative treatment

BackgroundThe TNM staging system is far from perfect in predicting the survival of individual cancer patients because only the gross anatomy is considered. The survival rates of the patients who have the same TNM stage disease vary across a wide spectrum. This study aimed to develop a nomogram that incorporates other clinicopathologic factors for predicting the overall survival (OS) of non-metastatic nasopharyngeal carcinoma (NPC) patients after curative treatments.MethodsWe retrospectively collected the clinical data of 1520 NPC patients who were diagnosed histologically between November 2000 and September 2003. The clinical data of a separate cohort of 464 patients who received intensity-modulated radiation therapy (IMRT) between 2001 and 2010 were also retrieved to examine the extensibility of the model. Cox regression analysis was used to identify the prognostic factors for building the nomogram. The predictive accuracy and discriminative ability were measured using the concordance index (c-index).ResultsWe identified and incorporated 12 independent clinical factors into the nomogram. The calibration curves showed that the prediction of OS was in good agreement with the actual observation in the internal validation set and IMRT cohort. The c-index of the nomogram was statistically higher than that of the 7th edition TNM staging system for predicting the survival in both the primary cohort (0.69 vs. 0.62) and the IMRT cohort (0.67 vs. 0.63).ConclusionWe developed and validated a novel nomogram that outperformed the TNM staging system in predicting the OS of non-metastatic NPC patients who underwent curative therapy.

The Difference of Clinical Characteristics between Patients with Exon 19 Deletion and Those with L858R Mutation in Nonsmall Cell Lung Cancer

AbstractRecent studies have demonstrated that exon 19 deletion (19 Del) and exon 21 L858R mutation (L858R) are 2 different types of sensitive epidermal growth factor receptor (EGFR) mutations in nonsmall cell lung cancer (NSCLC). However, whether there are some differences between those 2 groups in baseline clinical characteristics is still unclear.We enrolled consecutive 1271 NSCLC patients detected with either 19 Del or L858R and collected their baseline clinical characteristics including age, sex, comorbidity, smoking and drinking status, body mass index (BMI), TNM stage, histologic type, differentiation, tumor maximum diameter (TMD), and CEA level. &khgr;2 test and multivariate logistic regression analysis were used to compare the difference.We found a higher percentage of 19 Del in younger patients group (< = 50 yr) than L858R (P < 0.001) through &khgr;2 test. Besides, patients with 19 Del have higher risk of lymph node metastasis (P < 0.001). However, there were no significant differences in other items of clinical characteristics between 19 Del and L858R. Multivariate analysis showed similar significant results. Subgroup analysis in different age groups (10 yr as an interval) and N stages (stratified by N0, N1, N2, and N3) also indicated above-mentioned trends.NSCLC patients with 19 Del are more likely to be young and have lymphatic metastasis than those with L858R. Age and N stage might be considered in predicting EGFR mutation type in NSCLC.

Neurokinin-1 Receptor Antagonist-Based Triple Regimens in Preventing Chemotherapy-Induced Nausea and Vomiting: A Network Meta-Analysis

Background: Neurokinin‐1 receptor antagonists (NK‐1RAs) are widely used for chemotherapy‐induced nausea and vomiting (CINV) control in patients with highly emetogenic chemotherapy (HEC) and/or moderately emetogenic chemotherapy (MEC). Whether the efficacy and toxicity of antiemesis are different among various NK‐1RA‐based triple regimens is unknown. Methods: Data of complete responses (CRs) in the acute, delayed, and overall phases and treatment‐related adverse events (TRAEs) were extracted from electronic databases. Efficacy and toxicity were integrated by pairwise and network meta‐analyses. Results: Thirty‐six trials involving 18 889 patients using triple regimens (NK‐1RA+serotonin receptor antagonists [5HT3RA] + dexamethasone) or duplex regimen (5HT3RA+dexamethasone) to control CINV were included in the analysis. Different NK‐1RA‐based triple regimens shared equivalent effect on CRs. In patients with HEC, almost all triple regimens showed statistically significantly higher CRs than duplex regimen (odds ratio [OR]duplex/triple = 0.47‐0.66). However, in patients with MEC, only aprepitant‐based triple regimen showed better effect than duplex regimen statistically significantly in CRs (ORduplex/triple = 0.52, 95% confidence interval [CI] = 0.34 to 0.68). No statistically significant difference of TRAEs was found among different triple regimens. Palonosetron‐based triple regimens were equivalent to first‐generation 5HT3RAs‐based triple regimens for CRs. Moreover, different doses of dexamethasone plus NK‐1RA and 5HT3RA showed no statistically significant difference in CRs. Conclusions: Different NK‐1RAs‐based triple regimens shared equivalent effect on CINV control. Various triple regimens had superior antiemetic effect than duplex regimen in patients with HEC. Only aprepitant‐based triple regimen showed better CINV control compared with duplex regimen in patients receiving MEC. Palonosetron and first‐generation 5HT3RAs might share equivalent CINV control in the combination of NK‐1RAs and dexamethasone. Lower doses of dexamethasone might be applied when used with NK‐1RAs and 5HT3RAs.