Glabridin and Anti-Non-Muscle Myosin IIA Therapy Disrupts Non-Small Cell Lung Carcinoma Motility

Lung cancer is the leading cause of cancer related death in the United States killing over 130,000 people each year. While a combination of chemo and radiation therapy may be effective, surgery is still required for many patients. Without surgery, the disease may progress and lead to metastases. We sought to determine if treatment with anti-non-muscle myosin IIA antibody would inhibit movement of the cells in the presence and absence of glabridin (an isoflavonoid compound shown to inhibit cell migration by inhibiting myosin). We compared inhibition by glabridin to that of an anti-non-muscle myosin IIA antibody and a combination therapy of both at 12 and 24 hours post wound creation. Cells that took up the anti-non-muscle myosin IIA antibody were greatly inhibited in motility and exhibited no significant change in wound healing. Glabridin treatment resulted in a dramatic increase in wound size within 12 hours and regeneration within 24 hours. The greatest decrease in motility was observed in cells treated with the combination of both glabridin and anti-non-muscle myosin IIA antibody. By 24 hrs, cell migration had halted due to death of the cells resulting from this combination. Further testing needs to be done to determine a safe mode of delivery of the combination therapy to ensure only local distribution. Controlled release drug delivery depot systems have been used as a means to provide local release of drugs intra-tumorally or adjacent to the cancerous tissue after surgical resection and have great potential.

Leveraging diverse cell-death patterns to predict the clinical outcome of immune checkpoint therapy in lung adenocarcinoma:Based on muti-omics analysis and vitro assay

Advanced LUAD shows limited response to treatment including immune therapy.With the development of sequencing omics,it is urgent to combine high-throughput multi-omics data to identify new immune checkpoint therapeutic response markers.Using GSE72094(n=386)and GSE31210(n=226)gene expression profile data in the GEO database,we identified genes associated with lung adenocarcinoma(LUAD)death using tools such as“edgeR”and“maftools”and visualized the characteristics of these genes using the“circlize”R package.We constructed a prognostic model based on death-related genes and optimized the model using LASSO-Cox regression methods.By calculating the cell death index(CDI)of each individual,we divided LUAD patients into high and low CDI groups and examined the relationship between CDI and overall survival time by principal component analysis(PCA)and Kaplan-Meier analysis.We also used the“ConsensusClusterPlus”tool for unsupervised clustering of LUAD subtypes based on model genes.In addition,we collected data on the expression of immunomodulatory genes and model genes for each cohort and performed tumor microenvironment analyses.We also used the TIDE algorithm to predict immunotherapy responses in the CDI cohort.Finally,we studied the effect of PRKCD on the proliferation and migration of LUAD cells through cell culture experiments.The study utilized the TCGA-LUAD cohort(n=493)and identified 2,901 genes that are differentially expressed in patients with LUAD.Through KEGG and GO enrichment analysis,these genes were found to be involved in a wide range of biological pathways.The study also used univariate Cox regression models and LASSO regression analyses to identify 17 candidate genes that were best associated with mortality prognostic risk scores.By comparing the overall survival(OS)outcomes of patients with different CDI values,it was found that increased CDI levels were significantly associated with lower OS rates.In addition,the study used unsupervised cluster analysis to divide 115 LUAD patients into two distinct clusters with significant differences in OS timing.Finally,a prognostic indicator called CDI was established and its feasibility as an independent prognostic indicator was evaluated by Cox proportional risk regression analysis.The immunotherapy efficacy was more sensitive in the group with high expression of programmed cell death models.Relationship between programmed cell death(PCD)signature models and drug reactivity.After evaluating the median inhibitory concentration(IC50)of various drugs in LUAD samples,statistically significant differences in IC50 values were found in cohorts with high and low CDI status.Specifically,Gefitinib and Lapatinib had higher IC50 values in the high-CDI cohort,while Olaparib,Oxaliplatin,SB216763,and Axitinib had lower values.These results suggest that individuals with high CDI levels are sensitive to tyrosine kinase inhibitors and may be resistant to conventional chemotherapy.Therefore,this study constructed a gene model that can evaluate patient immunotherapy by using programmed cell death-related genes based on muti-omics.The CDI index composed of these programmed cell death-related genes reveals the heterogeneity of lung adenocarcinoma tumors and serves as a prognostic indicator for patients.

Molecularly targeted therapies for advanced or metastatic non-small-cell lung carcinoma

Non-small-cell lung cancer(NSCLC)remains the leading cause of cancer-related death in both men and women in the United States.Platinum-based doublet chemotherapy has been a standard for patients with advanced stage disease.Improvements in overall survival and quality of life have been modest.Improved knowledge of the aberrant molecular signaling pathways found in NSCLC has led to the development of biomarkers with associated targeted therapeutics,thus changing the treatment paradigm for many NSCLC patients.In this review,we present a summary of many of the currently investigated biologic targets in NSCLC,discuss their current clinical trial status,and also discuss the potential for development of other targeted agents.

Accuracy of endoscopic ultrasound-guided needle aspiration specimens for molecular diagnosis of non-small-cell lung carcinoma

BACKGROUND Endoscopic ultrasonography-guided fine-needle aspiration(EUS-FNA)and endobronchial ultrasound-guided transbronchial needle aspiration(EBUS-TBNA)are highly sensitive for diagnosing and staging lung cancer.In recent years,targeted therapy has shown great significance in the treatment of non-small cell lung carcinoma(NSCLC).Using these minimally invasive techniques to obtain specimens for molecular testing will provide patients with a more convenient diagnostic approach.AIM To evaluate the feasibility and accuracy of tissue samples obtained using EUSFNA and EBUS-TBNA for molecular diagnosis of NSCLC.METHODS A total of 83 patients with NSCLC underwent molecular testing using tissues obtained from EUS-FNA or EBUS-TBNA at the Tianjin Medical University Cancer Hospital from January 2017 to June 2019.All enrolled patients underwent chest computed tomography or positron emission tomography/computed tomography prior to puncture.We detected abnormal expression of EGFR,KRAS,MET,HER2,ROS1 and anaplastic lymphoma kinase protein.Two patients failed to complete molecular testing due to insufficient tumor tissue.The clinical features,puncture records,molecular testing results and targeted treatment in the remaining 81 patients were summarized.RESULTS In a total of 99 tissue samples obtained from 83 patients,molecular testing was successfully completed in 93 samples with a sample adequacy ratio of 93.9%(93/99).Biopsy samples from two patients failed to provide test results due to insufficient tumor tissue.In the remaining 81 patients,62 cases(76.5%)were found to have adenocarcinoma,11 cases(13.6%)had squamous cell carcinoma,3 cases(3.7%)had adenosquamous carcinoma and 5 cases(6.2%)had NSCLC-not otherwise specified.The results of molecular testing showed EGFR mutations in 21 cases(25.9%),KRAS mutations in 9 cases(11.1%),ROS-1 rearrangement in 1 case(1.2%)and anaplastic lymphoma kinase-positive in 5 cases(6.2%).Twentyfour patients with positive results received targeted therapy.The total effectiveness rate of targeted therapy was 66.7%(16/24),and the disease control rate was 83.3%(20/24).CONCLUSION Tissue samples obtained by EUS-FNA or EBUS-TBNA are feasible for the molecular diagnosis of NSCLC and can provide reliable evidence for clinical diagnosis and treatment.

Advanced lung adenocarcinoma with EGFR 19-del mutation transforms into squamous cell carcinoma after EGFR tyrosine kinase inhibitor treatment

In this editorial we comment on the article by Ji et al.We focus specifically on the EGFR tyrosine kinase inhibitor(EGFR-TKI)treatment and the development of drug resistance to EGFR-TKIs.

Antibody-platinum(IV)prodrugs conjugates for targeted treatment of cutaneous squamous cell carcinoma

Antibody-drug conjugates(ADCs)are a new type of targeting antibodies that conjugate with highly toxic anticancer drugs via chemical linkers to exert high specificity and efficient killing of tumor cells,thereby attracting considerable attention in precise oncology therapy.Cetuximab(Cet)is a typical antibody that offers the benefits of good targeting and safety for individuals with advanced and inoperable cutaneous squamous cell carcinoma(cSCC);however,its anti-tumor activity is limited to a single use.Cisplatin(CisPt)shows good curative effects;however,its adverse effects and non-tumor-targeting ability are major drawbacks.In this study,we designed and developed a new ADC based on a new cytotoxic platinum(IV)prodrug(C8Pt(IV))and Cet.The so-called antibody-platinum(IV)prodrugs conjugates,named Cet-C8Pt(IV),showed excellent tumor targeting in cSCC.Specifically,it accurately delivered C8Pt(IV)into tumor cells to exert the combined anti-tumor effect of Cet and CisPt.Herein,metabolomic analysis showed that Cet-C8Pt(IV)promoted cellular apoptosis and increased DNA damage in cSCC cells by affecting the vitamin B6 metabolic pathway in tumor cells,thereby further enhancing the tumor-killing ability and providing a new strategy for clinical cancer treatment using antibody-platinum(IV)prodrugs conjugates.

Hepatic cancer stem cells and drug resistance: Relevance in targeted therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of most common malignancies in the world. Systemic treatments for HCC, particularly for advanced stages, are limited by the drug resistance phenomenon which ultimately leads to therapy failure. Recent studies have indicated an association between drug resistance and the existence of the cancer stem cells (CSCs) as tumor initiating cells. The CSCs are resistant to conventional chemotherapies and might be related to the mechanisms of the ATP Binding Cassette (ABC) transporters and alterations in the CSCs signaling pathways. Therefore, to contribute to the development of new HCC treatments, further information on the characterization of CSCs, the modulation of the ABC transporters expression and function and the signaling pathway involved in the self renewal, initiation and maintenance of the cancer are required. The combination of transporters modulators/inhibitors with molecular targeted therapies may be a potent strategy to block the tumoral progression. This review summarizes the association of CSCs, drug resistance, ABC transporters activities and changes in signaling pathways as a guide for future molecular therapy for HCC.

Clinical Observation on Treatment of NonParvicellular Carcinoma of the Lung with Jin Fu Kang Oral Liquid

Jin Fu Kang Oral Liquid ([symbol: see text]), made of traditional Chinese drugs for supplementing qi and nourishing yin, was developed according to the common symptoms in lung carcinoma with deficiency of both qi and yin. Of the 96 cases in the Jin Fu Kang group, 1 case got complete remission (CR) after treatment, 8 cases partial remission (PR), 52 cases no change (NC), PR + NC covering 63.5%. Of the 52 cases in the group of Jin Fu Kang plus chemotherapy, 11 cases got PR after treatment, 26 cases NC, PR + NC covering 71.2%. Of the 25 cases in the chemotherapy group, 4 cases got PR after treatment, 11 cases NC, PR + NC covering 60.0%. The results show that the therapeutic effectiveness in the Jin Fu Kang group and the group of Jin Fu Kang plus chemotherapy was better than that in the chemotherapy group. The one-year survival rate and the two-year survival rate after treatment in the Jin Fu Kang group were 67.3% and 67.3% respectively; 66.7% and 66.7% in the group of Jin Fu Kang plus chemotherapy; and 40.3% and 0.0% in the chemotherapy group. The improvement of clinical symptoms, increase of body weight and improvement of health situation (KPS marks) after treatment in both the Jin Fu Kang group and the group of Jin Fu Kang plus chemotherapy were better than that in the chemotherapy group. Some indicators of immunology and hemogram after treatment were greatly improved in the Jin Fu Kang group, worse in the chemotherapy group, but no obvious improvement in the group of Jin Fu Kang plus chemotherapy.

Advanced Lung Adenocarcinoma with EGFR 19-del Mutation Transformed into SCC after EGFR-tyrosine Kinase inhibitors Treatment:A Case report

BACKGROUND Epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs)significantly improve the survival of patients with Epidermal growth factor receptor(EGFR)sensitive mutations in non-small cell lung cancer(NSCLC).CASE SUMMARY A 67-year-old female patient in advanced lung adenocarcinoma suffered from drug resistance after EGFR-TKIs treatment.Secondary pathological tissue biopsy confirmed squamous cell carcinoma(SCC)transformation.Patients inevitably encountered drug resistance issues after receiving EGFR-TKIs treatment for a certain period of time,while EGFR-TKIs can significantly improve the survival of patients with EGFR-sensitive mutations in NSCLC.Notably,EGFR-TKIs resistance includes primary and acquired.Pathological transformation is one of the mechanisms of acquired resistance in EGFR-TKIs,with SCC transformation being relatively rare.Our results provide more detailed results of the patient’s diagnosis and treatment process on SCC transformation after EGFR-TKIs treatment for lung adenocarcinoma.CONCLUSION Squamous cell carcinoma transformation is one of the acquired resistance mechanisms of EGFR-TKIs in advanced lung adenocarcinoma with EGFR mutations.

EGFR mutation identifies distant squamous cell carcinoma as metastasis from lung adenocarcinoma

Lung cancer metastasis is typically determined by histologic similarity between distant and primary lesions. Herein, we present a 70-year-old Japanese woman with an adenocarcinoma in her lung and a squamous cell carcinoma in her femur; both tumors had an identical epidermal growth factor receptor mutation, G719 S. This indicated that both tumors had a common origin, despite their histologic dissimilarity. The tumor in the femur was thus identified genetically as a lung cancer metastasis. This case suggests that genetic analysis can determine whether a distant lesion is a lung cancermetastasis, particularly when the histology differs from that of the primary lesion.

Alectinib treatment for 2 non-small cell lung carcinoma patients carrying different novel ALK fusions

The genomic fusions of the anaplastic lymphoma kinase(ALK)gene have been widely recognized as effective therapeutic targets for non-small cell lung carcinoma(NSCLC).The Second Xiangya Hospital of Central South University has treated 2 NSCLC patients with 2 distinct novel ALK gene fusions.Case 1 was a 55-year-old male with a solid nodule located in the right hilar lobe on enhanced CT scan.Case 2 was a 47-year-old female with enhanced CT showing involvement of the left upper lobe of lung.Histopathological examination of tumor tissues confirmed lung adenocarcinoma in both cases.Immunohistochemical(IHC)staining demonstrated positivity for thyroid transcription factor 1(TTF-1)and ALK-D5F3 in tumor cells,while negativity for P40.The next-generation sequencing(NGS)tests identified a PNPT1-ALK(Exon22:Exon20)fusion variant in case 1 and a TCEAL2-ALK(Exon3:Exon19)fusion variant in case 2.The TCEAL2-ALK fusion was further confirmed by amplification refractory mutation system(ARMS)-PCR at the mRNA level.Both patients were treated with oral alectinib at a dosage of 600 mg twice daily.The tumors in both patients were significantly decreased after alectinib treatment,achieving partial response.At the time of submission,there was an absence of disease progression and the progression-free survival(PFS)had surpassed 1 year.It offered compelling evidences that the individuals with NSCLC and harboring either a PNPT1-ALK(Exon22:Exon20)fusion or a TCEAL2-ALK(Exon3:Exon19)fusion,experience favorable therapeutic outcomes through the administration of alectinib.This study expands the known ALK fusion variants database and supports the precision treatment of NSCLC using ALK tyrosine kinase inhibitors(TKIs).

Role of deubiquitinase JOSD2 in the pathogenesis of esophageal squamous cell carcinoma

BACKGROUND Esophageal squamous cell carcinoma(ESCC)is a deadly malignancy with limited treatment options.Deubiquitinases(DUBs)have been confirmed to play a crucial role in the development of malignant tumors.JOSD2 is a DUB involved in con-trolling protein deubiquitination and influencing critical cellular processes in cancer.AIM To investigate the impact of JOSD2 on the progression of ESCC.METHODS Bioinformatic analyses were employed to explore the expression,prognosis,and enriched pathways associated with JOSD2 in ESCC.Lentiviral transduction was utilized to manipulate JOSD2 expression in ESCC cell lines(KYSE30 and RESULTS )Preliminary research indicated that JOSD2 was highly expressed in ESCC tissues,which was associated with poor prognosis.Further analysis demonstrated that JOSD2 was upregulated in ESCC cell lines compared to normal esophageal cells.JOSD2 knockdown inhibited ESCC cell activity,including proliferation and colony-forming ability.Moreover,JOSD2 knockdown decreased the drug resistance and migration of ESCC cells,while JOSD2 overexpression enhanced these phenotypes.In vivo xenograft assays further confirmed that JOSD2 promoted tumor proliferation and drug resistance in ESCC.Mechanistically,JOSD2 appears to activate the MAPK/ERK and PI3K/AKT signaling pathways.Mass spectrometry was used to identify crucial substrate proteins that interact with JOSD2,which identified the four primary proteins that bind to JOSD2,namely USP47,IGKV2D-29,HSP90AB1,and PRMT5.CONCLUSION JOSD2 plays a crucial role in enhancing the proliferation,migration,and drug resistance of ESCC,suggesting that JOSD2 is a potential therapeutic target in ESCC.

Neoadjuvant Therapy for Locally Advanced Renal Cell Carcinoma with Sorafenib in a Reference Center in Mexico

Background: neo - adjuvant therapy is usually indicated in locally advanced tumors, the aim is to decrease the tumoral burden and enhance overall survival. Renal cell carcinoma is a chemo and radio resistant neoplasm and this type of approach is not as effective as in other solid tumors. On the other hand immunotherapy is indicated in metastatic disease, demonstrating a better overall survival. Sorafenib is an antiangiogenic drug approved for locally advanced or metastatic RCC. We postulated that it can be used in a neoadjuvant way to decrease the vascularization of selected tumors. Report of the case: 57 years old male referred to our service with a right renal mass and metastatic disease to lumbar spine and suprarenal gland. He was treated with three months of sorafenib previous to the surgery. Results: The patient went into surgery three months after initiating the antiangiogenic drug, during the surgery we found less neo-formance vessels;the dissection was subjectively easier, due to peri-renal edema. The pathologic analysis of the specimen was renal cell carcinoma. Interestingly, 40% of central ischemic (coagulative) necrosis was found. Conclusion: There are no neoadjuvant drugs accepted for the treatment of renal cell carcinoma;using an antiagiogenic drug to decrease the vascular burden characteristic of this type of tumors could be a viable option in selected cases. We used a lower dose of the drug with an acceptable safety profile.

Evaluation of Targeted Therapy for Locally Advanced or Metastatic Renal Cell Carcinoma in Tunisia

Introduction: Renal cell carcinoma (RCC) is known to be chemo resistant but with the introduction of targeted therapies;there has been a “revolution” in its treatment strategies. The only targeted therapy available in Tunisia for the treatment of metastatic and/or locally advanced RCC is sunitinib. Objective of the Study: To evaluate therapeutic results and tolerance of sunitinib in metastatic and/or locally advanced RCC. Subjects and Methods: This was a retrospective study covering a period of six years (from January 2008 to January 2014) conducted in 5 medical oncology departments in Tunisia. The population of the study consisted of 29 patients treated with sunitinib for metastatic and/or locally advanced RCC. Results: The mean age of patients was 51 years. Three patients had tumor recurrence and 26 patients had a metastatic RCC. The prognosis was good for 5 patients, intermediate for 19 patients and poor for 5 patients. The median duration of treatment was 5 months. Because of side effects, treatment was discontinued in 12.5% of cases and the dose was reduced in 10.3% of cases. Side effects consisted of asthenia (95.8%), stomatitis (70.8%), anemia (50%), hand-foot syndrome (55.8%) in addition to nausea and vomiting (54.2%). Objective response was observed in 37.5% of patients after 3 months of treatment and in 50% after 6 months. The median progression-free survival was 14 months (95% CI, 7.9 to 20.6). The median overall survival was 22 months (95% CI, 15.6 to 28.7). Conclusion: The prognosis of RCC in Tunisian patients has clearly improved with the introduction of sunitinib, but other therapies with a proven efficacy as a first and second line therapy should be considered.

Research progress on dynamic monitoring of ctDNA and drug resistance related concomitant mutations in non-small cell lung cancer

Owing to significantly prolonged survival,targeted therapy has become standardized recommendation for advanced non-small cell lung cancer patients with mutated driver genes.However,the genetic status of lung cancer patients is dynamic.By dynamically monitoring the evolution of genes status,differential genes and concomitant genes related to progressive disease could be confirmed early,so as to achieve a more accurate and comprehensive insight of the whole process management of targeted therapy for lung cancer patients.Under the guidance of accurate genetic testing results,it is helpful to provide patients with more effective,long-term,and stable individualized targeted therapy.

Favorable response of primary pulmonary lymphoepithelioma-like carcinoma to sintilimab combined with chemotherapy: A case report

BACKGROUND There is no established treatment for primary pulmonary lymphoepithelioma-like carcinoma(LELC)until now.CASE SUMMARY In this study,the patient responded well to sintilimab combined with paclitaxel and carboplatin,showing no obvious side effects.Meantime,the values of carbohydrate antigen 15-3(CA15-3)and carbohydrate antigen 72-4(CA72-4)gradually returned to normal.CONCLUSION Immunotherapy combined with chemotherapy in advanced-stage LELC may be more effective than immunotherapy or chemotherapy alone.CA15-3 and CA72-4 are biomarkers for evaluating therapeutic effects for LELC.

Gli1 promotes epithelial-mesenchymal transition and metastasis of non-small cell lung carcinoma by regulating snail transcriptional activity and stability

Metastasis is crucial for the mortality of non-small cell lung carcinoma(NSCLC) patients.The epithelial-mesenchymal transition(EMT) plays a critical role in regulating tumor metastasis.Glioma-associated oncogene 1(Gli1) is aberrantly active in a series of tumor tissues. However, the molecular regulatory relationships between Gli1 and NSCLC metastasis have not yet been identified. Herein,we reported Gli1 promoted NSCLC metastasis. High Gli1 expression was associated with poor survival of NSCLC patients. Ectopic expression of Gli1 in low metastatic A549 and NCI-H460 cells enhanced their migration, invasion abilities and facilitated EMT process, whereas knock-down of Gli1 in high metastatic NCI-H1299 and NCI-H1703 cells showed an opposite effect. Notably, Gli1 overexpression accelerated the lung and liver metastasis of NSCLC in the intravenously injected metastasis model. Further research showed that Gli1 positively regulated Snail expression by binding to its promoter and enhancing its protein stability, thereby facilitating the migration, invasion and EMT of NSCLC. In addition, administration of GANT-61, a Gli1 inhibitor, obviously suppressed the metastasis of NSCLC. Collectively, our study reveals that Gli1 is a critical regulator for NSCLC metastasis and suggests that targeting Gli1 is a prospective therapy strategy for metastatic NSCLC.

Adenocarcinoma transformed into squamous cell carcinoma in non-small cell lung cancer

Non-small cell lung cancer(NSCLC)is the most common form of lung cancer which remains the deadliest malignancy worldwide(Siegel et al.,2019).In general,NSCLC can be divided into several subtypes,including adenocarcinoma(ADC),squamous cell carcinoma(SCC),adeno-squamous cell carcinoma(AD-SCC)and large cell carcinoma(LCC).

Advances in adjuvant systemic therapy for non-small-cell lung cancer

Non-small-cell lung cancer remains a leading cause of death around the world. For most cases, the only chance of cure comes from resection for localised disease, however relapse rates remain high following surgery. Data has emerged over recent years regarding the utility of adjuvant chemotherapy for improving disease-free and overall survival of patients following curative resection. This paper reviews the clinical trials that have been conducted in this area along with the studies integrating radiation therapy in the adjuvant setting. The role of prognostic gene signatures are reviewed as well as ongoing clinical trials including those incorporating biological or targeted therapies.

Efficacy and safety of dacomitinib as first-line treatment for advanced non-small cell lung cancer patients with epidermal growth factor receptor 21L858R mutation:A multicenter,case-series study in China

Objective:To provide real-world evidence for the application of first-line dacomitinib treatment for epidermal growth factor receptor(EGFR)21L858R mutant non-small cell lung cancer(NSCLC)patients in China and to explore the factors influencing the efficacy and safety.Methods:A longitudinal,consecutive case-series,multicenter study with mixed prospective and retrospective data was conducted.The primary endpoint was progression-free survival(PFS),and the secondary endpoints included duration of treatment(DOT),overall survival(OS),objective response rate(ORR),disease control rate(DCR)and safety.Results:A total of 155 EGFR 21L858R mutant patients treated with first-line dacomitinib were included.The median follow-up time for these patients was 20.4 months.Among 134 patients with evaluable lesions,the ORR was 70.9%and the DCR was 96.3%.The median PFS was 16.3[95%confidence interval(95%CI),13.7−18.9]months.Multivariate Cox regression analysis suggested that the baseline brain metastasis(BM)status[with vs.without BM:hazard ratio(HR),1.331;95%CI,0.720−2.458;P=0.361]and initial doses(45 mg vs.30 mg:HR,0.837;95%CI,0.427−1.641;P=0.604)did not significantly affect the median PFS.The median DOT was 21.0(95%CI,17.5−24.6)months and the median OS was not reached.Genetic tests were performed in 64 patients after progression,among whom 29(45.3%)patients developed the EGFR 20T790M mutation.In addition,among the 46 patients who discontinued dacomitinib treatment after progression,31(67.4%)patients received subsequent third-generation EGFR-tyrosine kinase inhibitors.The most common grade 3−4 adverse events were rash(10.4%),diarrhea(9.1%),stomatitis(7.1%)and paronychia(4.5%).The incidence of grade 3−4 rash was significantly higher in the 45 mg group than that in the 30 mg group(21.9%vs.7.5%,P=0.042).Conclusions:First-line dacomitinib treatment demonstrated promising efficacy and tolerable adverse events among EGFR 21L858R mutant NSCLC patients in China.