PRaG 3.0 therapy for human epidermal growth factor receptor 2-positive metastatic pancreatic ductal adenocarcinoma:A case report

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly fatal disease with limited effective treatment especially after first-line chemotherapy.The human epidermal growth factor receptor 2(HER-2)immunohistochemistry(IHC)positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC.CASE SUMMARY We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn’t have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment.A novel combination therapy PRaG 3.0 of RC48(HER2-antibody-drug conjugate),radio-therapy,PD-1 inhibitor,granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month.She had not developed any grade 2 or above treatment-related adverse events at any point.Percentage of peripheral CD8^(+) Temra and CD4^(+) Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy.CONCLUSION PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.

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.

Inetetamab combined with S-1 and oxaliplatin as first-line treatment for human epidermal growth factor receptor 2-positive gastric cancer

BACKGROUND Patients with human epidermal growth factor receptor 2(HER2)-positive advanced gastric cancer have poor outcomes.Trastuzumab combined with chemotherapy is the first-line standard treatment for HER2-positive advanced gastric cancer.Inetetamab is a novel anti-HER2 drug,and its efficacy and safety in gastric cancer have not yet been reported.AIM To evaluate the efficacy and safety of the S-1 plus oxaliplatin(SOX)regimen combined with inetetamab as a first-line treatment for HER2-positive advanced gastric cancer.METHODS Thirty-eight patients with HER2-positive advanced gastric cancer or gastroeso-phageal junction adenocarcinoma were randomly divided into two groups:One group received inetetamab combined with the SOX regimen,and the other group received trastuzumab combined with the SOX regimen.After 4-6 cycles,patients with stable disease received maintenance therapy.The primary endpoints were progression-free survival(PFS)and overall survival(OS),and the secondary endpoints were the objective response rate,disease control rate,and adverse events(AEs).RESULTS Thirty-seven patients completed the trial,with 18 patients in the inetetamab group and 19 patients in the trastuzumab group.In the inetetamab group,the median PFS was 8.5 months,whereas it was 7.3 months in the trastuzumab group(P=0.046);this difference was significant.The median OS in the inetetamab group vs the trastuzumab group was 15.4 months vs 14.3 months(P=0.33),and the objective response rate was 50%vs 42%(P=0.63),respectively;these differences were not significant.Common AEs included leukopenia,thrombocytopenia,nausea,and vomiting.The incidence rates of grade≥3 AEs were 56%in the inetetamab group and 47%in the trastuzumab group(P=0.63),with no significant difference.CONCLUSION In the first-line treatment of HER2-positive advanced gastric cancer,inetetamab and trastuzumab showed comparable efficacy.The inetetamab group showed superior PFS,and both groups had good safety.

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance.Human epidermal growth factor receptor 2(HER2)is one of the most important targets in targeted therapy for gastric cancer.Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer.The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified.However,monoclonal antibodies,due to their large molecular weight,inability to penetrate the blood-brain barrier,and drug resistance,lead to decreased therapeutic efficacy,so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer.Small-molecule tyrosine kinase inhibitors,such as lapatinib and pyrrotinib,have the advantages of small molecular weight,penetrating the blood-brain barrier and high oral bioavailability,and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future.Antibo-drug conjugate,such as T-DM1 and T-DXd,can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing,and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab.Therefore,after more detailed stratification of gastric cancer patients,various gastric cancer drugs targeting HER2 are expected to play a more significant role.

Concomitant epidermal growth factor receptor mutation/c-ros oncogene 1 rearrangement in non-small cell lung cancer: A case report

BACKGROUND Epidermal growth factor receptor(EGFR)mutation and c-ros oncogene 1(ROS1)rearrangement are key genetic alterations and predictive tumor markers for non-small cell lung cancer(NSCLC)and are typically considered to be mutually exc-lusive.EGFR/ROS1 co-mutation is a rare event,and the standard treatment appr-oach for such cases is still equivocal.CASE SUMMARY Herein,we report the case of a 64-year-old woman diagnosed with lung adenocar-cinoma,with concomitant EGFR L858R mutation and ROS1 rearrangement.The patient received two cycles of chemotherapy after surgery,but the disease prog-ressed.Following 1-month treatment with gefitinib,the disease progressed again.However,after switching to crizotinib,the lesion became stable.Currently,crizotinib has been administered for over 53 months with a remarkable treatment effect.CONCLUSION The efficacy of EGFR tyrosine kinase inhibitors and crizotinib was vastly different in this NSCLC patient with EGFR/ROS1 co-mutation.This report will aid future treatment of such patients.

Human epidermal growth factor receptor 2 expression level and combined positive score can evaluate efficacy of advanced gastric cancer

BACKGROUND Although treatment options for gastric cancer(GC)continue to advance,the overall prognosis for patients with GC remains poor.At present,the predictors of treatment efficacy remain controversial except for high microsatellite instability.AIM To develop methods to identify groups of patients with GC who would benefit the most from receiving the combination of a programmed cell death protein 1(PD-1)inhibitor and chemotherapy.METHODS We acquired data from 63 patients with human epidermal growth factor receptor 2(HER2)-negative GC with a histological diagnosis of GC at the Cancer Hospital,Chinese Academy of Medical Sciences between November 2020 and October 2022.All of the patients screened received a PD-1 inhibitor combined with chemotherapy as the first-line treatment.RESULTS As of July 1,2023,the objective response rate was 61.9%,and the disease control rate was 96.8%.The median progression-free survival(mPFS)for all patients was 6.3 months.The median overall survival was not achieved.Survival analysis showed that patients with a combined positive score(CPS)≥1 exhibited an extended trend in progression-free survival(PFS)when compared to patients with a CPS of 0 after receiving a PD-1 inhibitor combined with oxaliplatin and tegafur as the first-line treatment.PFS exhibited a trend for prolongation as the expression level of HER2 increased.Based on PFS,we divided patients into two groups:A treatment group with excellent efficacy and a treatment group with poor efficacy.The mPFS of the excellent efficacy group was 8 months,with a mPFS of 9.1 months after excluding a cohort of patients who received interrupted therapy due to surgery.The mPFS was 4.5 months in patients in the group with poor efficacy who did not receive surgery.Using good/poor efficacy as the endpoint of our study,univariate analysis revealed that both CPS score(P=0.004)and HER2 expression level(P=0.015)were both factors that exerted significant influence on the efficacy of treatment the combination of a PD-1 inhibitor and chemotherapy in patients with advanced GC(AGC).Finally,multivariate analysis confirmed that CPS score was a significant influencing factor.CONCLUSION CPS score and HER2 expression both impacted the efficacy of immunotherapy combined with chemotherapy in AGC patients who were non-positive for HER2.

Therapeutic Effect of First-line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR-TKI)Combined with Whole Brain Radiotherapy on Patients with EGFR Mutation-positive Lung Adenocarcinoma and Brain Metastases

This study compared the therapeutic effect of first-line epidermal growth factor receptor tyrosine kinase inhibitor(EGFR-TKI)with that of EGFR-TKI plus whole brain radiotherapy(WBRT)on patients with EGFR mutation-positive lung adenocarcinoma and brain metastases.A total of 139 patients with lung adenocarcinoma and brain metastases treated with first-line EGFR-TK1therapy from September 2008 to December 2017 were enrolled in this study.The study endpoints were intracranial time to progression(TTP)and overall survival(OS).The effects of clinical pathological parameters and EGFR gene status on the study endpoints were compared.The results showed that the intracranial TTP was significantly longer in EGFR-TKI plus WBRT group than in EGFR-TKI group (median 30.0 vs.18.2 months,χ2=10.824,P=0.001),but no significant difference in the OS was noted between the two groups (median 48.0 vs.41.1 months,χ2=0.012, P=0.912).Also,there was no statistically significant difference in the OS between patients treated with early and late radiotherapy (P=0.849)and between those with asymptomatic and those with symptomatic intracranial metastases (P=0.189).The OS and intracranial TTP of patients with intracranial oligometastases (≤3metastatic sites)were not significantly different from those of patients with multiple intracranial metastases (P=0.104 and P=0.357,respectively),and exon 19 and exon 21 mutations didn't show significant effects on the OS and intracranial TTP of patients (P=0.418 and P=0.386,respectively).In conclusion,there was no statistically significant difference in the OS between the EGFR-TKI alone group and EGFR-TK1 plus WBRT group.However, simultaneous use of WBRT was found to significantly prolong intracranial TTP and improve cerebral symptoms,and thus EGFR-TKI and WBRT combined may be clinically beneficial for patients with EGFR mutation-positive lung adenocarcinoma and brain metastases.

Relationship between molecular changes in epidermal growth factor receptor(EGFR)and anaplastic lymphoma kinase(ALK)mutations in lung adenocarcinoma

Objective This study aimed to analyze the relationship between the mutations in epidermal growth factor receptor(EGFR)and anaplastic lymphoma kinase(ALK)and their impact on the prognosis and treatment of lung adenocarcinoma.Methods A total of 158 cases of lung adenocarcinoma reported between January 2007 and January 2014 were retrospectively analyzed.These tumors were resected using radical pneumonectomy and underwent pathology-based diagnosis at our institution(Inner Mongolia People’s Hospital,Hohhot,China).The tissue sections were evaluated using the updated World Health Organization classification of lung adenocarcinomas(2015 version),with each histological component recorded in 5%increments.The histological subtypes were classified,and any surviving cases were followed up.The reverse transcription-polymerase chain reaction(RT-PCR)and direct DNA sequencing were used to evaluate mutations in exons 18,19,20,and 21 in the EGFR gene,and the echinoderm microtubule-associated protein-like 4 gene-ALK variant(EML4-ALK)fusions were detected using sequencing.Results Our cohort included 25 patients with pre-invasive adenocarcinoma,13 patients with lepidic,66 patients with acinar,13 patients with papillary,and 25 patients with solid infiltrative adenocarcinoma with the remaining cases presenting with a variety of pathological subtypes.The prognosis of each histological subtype was different with the 5-year disease-free survival and 5-year overall survival(OS)of pre-invasion adenocarcinoma at 100%;the 5-year OS of lepidic,acinar,and papillary adenocarcinoma patients was only 84.6%,72.7%,and 76.9%,respectively.The 5-year OS of solid and mucinous adenocarcinomas were 32.0%and 36.4%,respectively.EGFR mutation was detected in 69 cases with a mutation rate of 43.7%and majority of these mutations were found in exons 19(50.6%)and 21(37.9%),with women and non-smokers shown to experience a higher mutation rate(P<0.05).However,histological subtype analysis showed that EGFR mutations were primarily found in adenocarcinomas.Most of these mutations were found in lepidic(53.8%)or acinar adenocarcinomas(50.0%),whereas these mutations were rare in both solid(28.0%)and mucinous adenocarcinoma(27.2%).The fusion mutation rate in the EML4-ALK gene was 5.69%,and was most common in young,nonsmoking patients(P<0.05).Conclusion The prognosis of patients in each lung adenocarcinoma subtype is different,and these outcomes are likely related to mutations in the EGFR and EML4-ALK genes.EGFR mutation rates are higher in lepidic and acinar adenocarcinomas,whereas EML4-ALK gene fusion mutations are more common in solid and mucinous adenocarcinoma.EGFR mutations are more common in female and non-smoking patients,whereas EML4-ALK fusions are more common in young,non-smoking patients.

Knockdown of HE4 suppresses tumor growth and invasiveness in lung adenocarcinoma through regulation of EGFR signaling

It has been shown that the high expression of human epididymis protein 4(HE4)in most lung cancers is related to the poor prognosis of patients,but the mechanism of pathological transformation of HE4 in lung cancer is still unclear.The current study is expected to clarify the function and mechanism of HE4 in the occurrence and metastasis of lung adenocarcinoma(LUAD).Immunoblotting evaluated HE4 expression in lung cancer cell lines and biopsies,and through analysis of The Cancer Genome Atlas(TCGA)dataset.Frequent HE4 overexpression was demonstrated in LUAD,but not in lung squamous cell carcinoma(LUSC),indicating that HE4 can serve as a biomarker to distinguish between LUAD and LUSC.HE4 knockdown significantly inhibited cell growth,colony formation,wound healing,and invasion,and blocked the G1-phase of the cell cycle in LUAD cell lines through inactivation of the EGFR signaling downstream including PI3K/AKT/mTOR and RAF/MAPK pathways.The first-line EGFR inhibitor gefitinib and HE4 shRNA had no synergistic inhibitory effect on the growth of lung adenocarcinoma cells,while the third-line EGFR inhibitor osimertinib showed additive anti-proliferative effects.Moreover,we provided evidence that HE4 regulated EGFR expression by transcription regulation and protein interaction in LUAD.Our findings suggest that HE4 positively modulates the EGFR signaling pathway to promote growth and invasiveness in LUAD and highlight that targeting HE4 could be a novel strategy for LUAD treatment.

Correlation of human epidermal growth factor receptor 2 expression with clinicopathological characteristics and prognosis in gastric cancer

AIM:To investigate human epidermal growth factor receptor 2(HER2) gene amplification and protein expression in Chinese patients with resectable gastric cancer and the association with clinicopathological characteristics and survival.METHODS:One hundred and ninety-seven gastric cancer patients who underwent curative surgery procedures were enrolled into this study.HER2 gene amplification and protein expression were examined using fluorescence in-situ hybridization(FISH) and immunohistochemistry(IHC) analysis on formalin-fixed paraffinembedded gastric cancer samples from all patients.For scoring,Hofmann's HER2 gastric cancer scoring system was adopted.All cases showing IHC3+ or FISH positiv-ity were defined as HER2 positive.Patient clinicopathological data and survival information were collected.Finally,χ 2 statistical analysis was performed to analyze the HER2 positivity rate amongst the subgroups with different clinicopathological characteristics including;gender,age,tumor location,Lauren classification,differentiation,TNM staging,depth of invasion,lymph node metastases and distant metastasis.The probability of survival for different subgroups with different clinicopathological characteristics was calculated using the Kaplan-Meier method and survival curves plotted using log rank inspection.RESULTS:According to Hofmann's HER2 gastric cancer scoring criteria,31 cases(15.74%) were identified as HER2 gene amplified and 19 cases(9.64%) were scored as strongly positive for HER2 membrane staining(3+),25 cases(12.69%) were moderately positive(2+) and 153 cases(77.66%) were HER2 negative(0/1+).The concordance rate between IHC and FISH analyses was 88.83%(175/197).Thirty-six cases were defined as positive for HER2 gene amplification and/or protein expression,with 24 of these cases being eligible for Herceptin treatment according to United States recommendations,and 29 of these cases eligible according to EU recommendations.Highly consistent results were detected between IHC3+,IHC0/1 and FISH(73.68% and 95.42%),but low consistency was observed between IHC2+ and FISH(40.00%).The positivity rates in intestinal type and well-differentiated gastric cancer were higher than those in diffuse/mixed type and poorly-differentiated gastric cancer respectively(28.57% vs 13.43%,P = 0.0103;37.25% vs 11.64%,P < 0.0001),but were not correlated with gender,age,tumor location or TNM stage,depth of invasion,lymph node metastases and distant metastasis.In poorly-differentiated gastric cancer patients,those without lymph node metastasis showed a higher HER2 positivity rate than those with lymph node metastasis(26.47% vs 7.14%,P = 0.0021).This association was not present in thosepatients with well-differentiated gastric cancer(28.57% vs 43.33%,P = 0.2832).Within our patient cohort,26 cases were lost to follow-up.The median survival time for the remaining 171 patients was 18 mo.The median survival times of the HER2 positive and negative groups were 17 and 18.5 mo respectively.Overall survival was not significantly different between HER2-positive and negative groups(χ 2 = 0.9157,P = 0.3386),but in patients presenting well-differentiated tumors,the overall survival of the HER2-positive group was significantly worse than that of the HER2-negative group(P = 0.0123).In contrast,patients with poorly differentiated and diffuse/mixed subtype gastric cancers showed no significant differences in overall survival associated with HER2.Furthermore,the median survival time of the HER2 positive group did not show any statistically significant differences when compared to the subgroups of gender,age,tumor location,TNM classification,lymph node metastases and distant metastasis.CONCLUSION:Patients with intestinal type gastric cancer(GC),well-differentiated GC and poorly-differentiated GC without lymph node metastasis,may all represent suitable candidates for targeted therapy using Herceptin.

A CT-based radiomics nomogram for prediction of human epidermal growth factor receptor 2 status in patients with gastric cancer

Objective: To develop and validate a computed tomography(CT)-based radiomics nomogram for predicting human epidermal growth factor receptor 2(HER2) status in patients with gastric cancer.Methods: This retrospective study included 134 patients with gastric cancer(HER2-negative: n=87;HER2-positive: n=47) from April 2013 to March 2018, who were then randomly divided into training(n=94) and validation(n=40) cohorts. Radiomics features were obtained from the CT images showing gastric cancer. Least absolute shrinkage and selection operator(LASSO) regression analysis was utilized for building the radiomics signature. A multivariable logistic regression method was applied to develop a prediction model incorporating the radiomics signature and independent clinicopathologic risk predictors, which were then visualized as a radiomics nomogram. The predictive performance of the nomogram was assessed in the training and validation cohorts.Results: The radiomics signature was significantly associated with HER2 status in both training(P<0.001) and validation(P=0.023) cohorts. The prediction model that incorporated the radiomics signature and carcinoembryonic antigen(CEA) level demonstrated good discriminative performance for HER2 status prediction,with an area under the curve(AUC) of 0.799 [95% confidence interval(95% CI): 0.704-0.894] in the training cohort and 0.771(95% CI: 0.607-0.934) in the validation cohort. The calibration curve of the radiomics nomogram also showed good calibration. Decision curve analysis showed that the radiomics nomogram was useful.Conclusions: We built and validated a radiomics nomogram with good performance for HER2 status prediction in gastric cancer. This radiomics nomogram could serve as a non-invasive tool to predict HER2 status and guide clinical treatment.

Role of human epidermal growth factor receptor 2 in gastric cancer:Biological and pharmacological aspects

Amplification of the human epidermal growth factor receptor 2 (HER2) gene and overexpression of the HER2 protein is found in 15%-20% of patients with gastric and gastroesophageal junction cancer. The degree of HER2 overexpression and amplification varies with the location of the carcinoma, with higher expression in the gastroesophageal and proximal parts compared to the distal parts of the stomach. Further, HER2 overexpression and amplification also seems to be related to the Lauren histological classification, with higher levels found in the intestinal phenotype compared to the diffuse and mixed types. The prognostic properties of HER2 overexpression and amplification are still under debate, but a large number of studies seem to indicate that HER2 is a negative prognostic factor. The usefulness of HER2 targeted therapy in gastric cancer was demonstrated in the ToGA trial, where HER2-positive patients with advanced gastric and gastroesophageal junction adenocarcinoma were randomized to receive 5-FU/capecitabine and cisplatin, either alone or in combination with trastuzumab. A statically significant gain in overall survival was seen in patients who received the combined treatment of trastuzumab and chemotherapy. Patients with a strong overexpression of the HER2 protein (IHC3+) specifically benefited from the treatment, with a median overall survival of 17.9 mo. As a consequence of the positive results of the ToGA trial, patients with advanced gastric or gastroesophageal junction adenocarcinoma are now routinely tested for HER2. The ToGA trial must be characterized as a landmark in the treatment of gastric cancer and it has paved the way for a number of new HER2 targeted compounds such as pertuzumab, ado-trastuzumab emtansine, lapatinib, afatinib, and dacomitinib, which are currently undergoing phase II and III clinical testing. Overall, this review will discuss the current status of HER2 in gastric and gastroesophageal junction cancer and the future direction in relation to HER2 target therapy.

Mechanisms of resistance to anti-epidermal growth factor receptor inhibitors in metastatic colorectal cancer

The prognosis of patients with metastatic colorectal cancer (mCRC) remain poor despite the impressive improvement of treatments observed over the last 20 years that led to an increase in median overall survival from 6 mo, with the only best supportive care, to approximately 30 mo with the introduction of active chemotherapy drugs and targeted agents. The monoclonal antibodies (moAbs) cetuximab and panitumumab, directed against the epidermal growth factor receptor (EGFR), undoubtedly represent a major step forward in the treatment of mCRC, given the relevant efficacy in terms of progression-free survival, overall survival, response rate, and quality of life observed in several phase III clinical trials among different lines of treatment. However, the anti-EGFR moAbs were shown only to be effective in a subset of patients. For instance, KRAS and NRAS mutations have been identified as biomarkers of resistance to these drugs, improving the selection of patients who might derive a benefit from these treatments. Nevertheless, several other alterations might affect the response to these drugs, and unfortunately, even the responders eventually become resistant by developing secondary (or acquired) resistance in approximately 13-18 mo. Several studies highlighted that the landscape of responsible alterations of both primary and acquired resistance to anti-EGFR drugs biochemically converge into MEK-ERK and PIK3CA-AKT pathways. In this review, we describe the currently known mechanisms of primary and acquired resistance to anti-EGFR moAbs together with the various strategies evaluated to prevent, overcame or revert them.

Alterations in the human epidermal growth factor receptor 2-phosphatidylinositol 3-kinase-v-Akt pathway in gastric cancer

AIM:To investigate human epidermal growth factor receptor 2(HER2)-phosphatidylinositol 3-kinase(PI3K)-vAkt murine thymoma viral oncogene homolog signaling pathway.METHODS:We analyzed 231 formalin-fixed,paraffinembedded gastric cancer tissue specimens from Japanese patients who had undergone surgical treatment.The patients' age,sex,tumor location,depth of invasion,pathological type,lymph node metastasis,and pathological stage were determined by a review of the medical records.Expression of HER2 was analyzed by immunohistochemistry(IHC) using the HercepTest TM kit.Standard criteria for HER2 positivity(0,1+,2+,and 3+) were used.Tumors that scored 3+ were considered HER2-positive.Expression of phospho Akt(pAkt) was also analyzed by IHC.Tumors were considered pAkt-positive when the percentage of positive tumor cells was 10% or more.PI3K,catalytic,alpha polypeptide(PIK3CA) mutations in exons 1,9 and 20 were analyzed by pyrosequencing.Epstein-Barr virus(EBV) infection was analyzed by in situ hybridization targeting EBV-encoded small RNA(EBER) with an EBER-RNA probe.Microsatellite instability(MSI) was analyzed by polymerase chain reaction using the mononucleotide markers BAT25 and BAT26.RESULTS:HER2 expression levels of 0,1+,2+ and 3+ were found in 167(72%),32(14%),12(5%) and 20(8.7%) samples,respectively.HER2 overexpression(IHC 3+) significantly correlated with intestinal histological type(15/20 vs 98 /205,P = 0.05).PIK3CA mutations were present in 20 cases(8.7%) and significantly correlated with MSI(10/20 vs 9/211,P < 0.01).The mutation frequency was high(21%) in T4 cancers and very low(6%) in T2 cancers.Mutations in exons 1,9 and 20 were detected in 5(2%),9(4%) and 7(3%) cases,respectively.Two new types of PIK3CA mutation,R88Q and R108H,were found in exon1.All PIK3CA mutations were heterozygous missense singlebase substitutions,the most common being H1047R(6/20,30%) in exon20.Eighteen cancers(8%) were EBV-positive and this positivity significantly correlated with a diffuse histological type(13/18 vs 93/198,P = 0.04).There were 7 cases of lymphoepithelioma-like carcinomas(LELC) and 6 of those cases were EBV-positive(percent/EBV:6/18,33%;percent/all LELC:6/7,86%).pAkt expression was positive in 119(53%) cases but showed no correlation with clinicopathological characteristics.pAkt expression was significantly correlated with HER2 overexpression(16/20 vs 103/211,P < 0.01) but not with PIK3CA mutations(12/20 vs 107/211,P = 0.37) or EBV infection(8/18 vs 103/211,P = 0.69).The frequency of pAkt expression was higher in cancers with exon20 mutations(100%) than in those with exon1(40%) or exon9(56%) mutations.One case showed both HER2 overexpression and EBV infection and 3 cases showed both PIK3CA mutations and EBV infection.However,no cases showed both PIK3CA mutations and HER2 overexpression.One EBVpositive cancer with PIK3CA mutation(H1047R) was MSI-positive.Three of these 4 cases were positive for pAkt expression.In survival analysis,pAkt expression significantly correlated with a poor prognosis(hazard ratio 1.75;95%CI:1.12-2.80,P = 0.02).CONCLUSION:HER2 expression,PIK3CA mutations and EBV infection in gastric cancer were characterized.pAkt expression significantly correlates with HER2 expression and with a poor prognosis.

Strategies to overcome resistance to epidermal growth factor receptor monoclonal antibody therapy in metastatic colorectal cancer

Administration of monoclonal antibodies(mAbs)against epidermal growth factor receptor(EGFR)such as cetuximab and panitumumab in combination with conventional chemotherapy substantially prolongs survival of patients with metastatic colorectal cancer(mCRC).However,the efficacy of these mAbs is limited due to genetic variation among patients,in particular K-ras mutations.The discovery of K-ras mutation as a predictor of non-responsiveness to EGFR mAb therapy has caused a major change in the treatment of mCRC.Drugs that inhibit transformation caused by oncogenic alterations of Ras and its downstream components such as BRAF,MEK and AKT seem to be promising cancer therapeutics as single agents or when given with EGFR inhibitors.Although multiple therapeutic strategies to overcome EGFR mAb-resistance are under investigation,our understanding of their mode of action is limited.Rational drug development based on stringent preclinical data,biomarker validation,and proper selection of patients is of paramount importance in the treatment of mCRC.In this review,we will discuss diverse approaches to overcome the problem of resistance to existing anti-EGFR therapies and potential future directions for cancer therapies related to the mutational status of genes associated with EGFRRas-ERK and PI3K signalings.

Colon cancer and the epidermal growth factor receptor:Current treatment paradigms,the importance of diet,and the role of chemoprevention

Colorectal cancer represents the third most common and the second deadliest type of cancer for both men and women in the United States claiming over 50000 lives in 2014. The 5-year survival rate for patients diagnosed with metastatic colon and rectal cancer is < 15%. Early detection and more effective treatments are urgently needed to reduce morbidity and mortality of patients afflicted with this disease. Here we will review the risk factors and current treatment paradigms for colorectal cancer, with an emphasis on the role of chemoprevention as they relate to epidermal growth factor receptor(EGFR) blockade. We will discuss how various EGFR ligands are upregulated in the presence of Western diets high in saturated and N-6 polyunsaturated fats. We will also outline the various mechanisms of EGFR inhibition that are induced by naturally occurring chemopreventative agents such as ginseng, green tea, and curcumin. Finally, we will discuss the current role of targeted chemotherapy in colon cancer and outline the limitations of our current treatment options, describing mechanisms of resistance and escape.

Oxidative stress affects retinal pigment epithelial cell survival through epidermal growth factor receptor/AKT signaling pathway

AIM：To investigate the cross-talk between oxidative stress and the epidermal growth factor receptor（EGFR）/AKT signaling pathway in retinal pigment epithelial（ RPE） cells.METHODS：Human RPE cell lines（ARPE-19 cell） were treated with different doses of epidermal growth factor（EGF） and hydrogen peroxide（H2O2）.Cell viability was determined by a methyl thiazolyl tetrazolium assay.Cell proliferation was examined by a bromodeoxyuridine（Brd U） incorporation assay.EGFR/AKT signaling was detected by Western blot.EGFR localization was also detected by immunofluorescence.In addition,EGFR/AKT signaling was intervened upon by EGFR inhibitor（erlotinib）,PI3 K inhibitor（A66） and AKT inhibitor（MK-2206）,respectively.H2O2-induced oxidative stress was blocked by antioxidant N-acetylcysteine（NAC）.RESULTS：EGF treatment increased ARPE-19 cell viabili ty and proliferation through inducing phosphorylation of EGFR and AKT.H2O2 inhibited ARPE-19 cell viability and proliferation and also suppressed EGF-stimulated increase of RPE cell viability and proliferation by affecting the EGFR/AKT signaling pathway.EGFR inhibitor erlotinib blocked EGF-induced phosphorylation of EGFR and AKT,while A66 and MK-2206 only blocked EGF-induced phosphorylation of AKT.EGF-induced phosphorylation andendocytosis of EGFR were also affected by H2O2 treatment.In addition,antioxidant NAC attenuated H2O2-induced inhibition of ARPE-19 cell viability through all eviating reduction of EGFR,and phosphorylated and total AKT proteins.CONCLUSION：Oxidative stress affects RPE cell viability and proliferation through interfering with the EGFR/AKT signaling pathway.The EGFR/AKT signaling pathway may be an important target in oxidative stress-induced RPE cell dysfunction.

Epidermal growth factor receptor and K-Ras in non-small cell lung cancer-molecular pathways involved and targeted therapies

Lung cancer is currently the leading cause of cancer death in Western nations.Non-small cell lung cancer(NSCLC)represents 80%of all lung cancers,and adenocarcinoma is the predominant histological type.Despite the intensive research carried out on this field and therapeutic advances,the overall prognosis of these patients remains unsatisfactory,with a 5-year overall survival rate of less than 15%.Nowadays,pharmacogenetics and pharmacogenomics represent the key to successful treatment.Recent studies suggest the existence of two distinct molecular pathways in the carcinogenesis of lung adenocarcinoma:one associated with smoking and activation of the K-Ras oncogene and the other not associated with smoking and activation of the epidermal growth factor receptor(EGFR).The K-ras mutation is mainly responsible for primary resistance to new molecules which inhibit tyrosine kinase EGFR(erlotinib and gefitinib)and most of the EGFR mutations are responsible for increased tumor sensitivity to these drugs.This article aims to conduct a systematic review of the literature regarding the molecular pathways involving the EGFR,K-Ras and EGFR targeted therapies in NSCLC tumor behavior.

Enhanced expression of epidermal growth factor receptor gene in gastric mucosal cells by the serum derived from rats treated with electroacupuncture at stomach meridian acupoints

AIM: To investigate the effect of serum derived from rats treated with electroacupuncture at stomach meridian acupoints on the expression of epidermal growth factor receptor (EGFR) gene in gastric mucosal cells. METHODS: The stress-induced gastric mucosal injury in rat model was established by water-immersion and restrained stress methods. 52 rats were randomly divided into: normal group (n = 8), model group (n = 8), model serum group (n = 12), stomach serum group (n = 12), and gallbladder serum group (n = 12). The gastric mucosal cells were separated by pronase-EDTA digestion method and incubated with serum. The EGFR gene expression in gastric mucosal cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: Compared with normal group (0.6860 ± 0.0594), the serum derived from rats of the stomach group (1.2272 ± 0.0813, P = 0.00 < 0.01) and gallbladder group (0.9640 ± 0.0387, P = 0.00 < 0.01) had a tendency to enhance the EGFR gene expression in gastric mucosal cells. Such tendency existed in the model group (0.7104 ± 0.0457) but with no signifi cant difference (P = 0.495 > 0.05) and in model serum group (0.8516 ± 0.0409) with an extremely obvious difference (P = 0.001 < 0.01). Furthermore, the EGFR gene expression in stomach serum group was significantly higher than that in gallbladder serum group (P = 0.00 < 0.01). CONCLUSION: The present study shows that serumderived from rats treated with electroacupuncture at stomach meridian acupoints can distinctly increase the EGFR gene expression of gastric mucosal cells. Therefore, there is certain meridian specificity in the serum, which could provide a proof for the TCM theory “particular relation between meridian and internal organ”.