Tyrosine kinase inhibitors and human epidermal growth factor receptor-2 positive breast cancer

The body of evidence investigating human epidermal growth factor receptor-2(HER2)directed therapy in patients with breast cancer(BC)has been growing within the last decade.Recently,the use of tyrosine kinase inhibitors(TKIs)has been of particular interest in the treatment of human malignancies.This literature commentary is intended to highlight the most recent findings associated with the widely-studied TKI agents and their clinical significance in improving the outcomes of HER2 positive BC.

Epidermal growth factor receptor tyrosine kinase inhibitors for non-small cell lung cancer

First-generation epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs), including gefitinib and erlotinib, have proven to be highly effective agents for advanced non-small cell lung cancer(NSCLC) in patients harboring an activating EGFR mutation such as the exon 19 deletion mutation and L858 R. Although those reversible small molecular targeted agents provide a significant response and survival benefit, all responders eventually acquire resistance. Secondgeneration EGFR-targeting agents, such as irreversible EGFR/HER2 tyrosine kinase inhibitors and pan-HER TKIs, may improve survival further and be useful for patients who acquired resistance to first-generation EGFR-TKIs. This review discusses novel therapeutic strategies for EGFR-mutated advanced NSCLC using first- and second-generation EGFR-TKIs.

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.

Review of epidermal growth factor receptor-tyrosine kinase inhibitors administration to non-small-cell lung cancer patients undergoing hemodialysis

Non-small-cell lung cancer(NSCLC)causes significant mortality worldwide.Patients with chronic renal failure have an increased risk of developing lungcancer.NSCLC Patients with chronic renal failure undergoing hemodialysis(HD)often exhibit poor performance,and chemotherapy is generally contraindicated.Oral epidermal growth factor receptor(EGFR)-tyrosine kinase inhibitors(TKIs)are effective treatment agents for NSCLC patients.However,the benefits andadverse effects of EGFR-TKIs in NSCLC undergoing HD are known.There are noclinical studies on the effects of EGFR-TKIs on NSCLC patients undergoing HD.We reviewed all previous case reports about EGFR-TKIs in NSCLC patientsundergoing HD.It is difficult to design studies about the effects of EGFR-TKIs inpatients undergoing HD,and this review is quite important.EGFR-TKIs are welltolerated in patients undergoing HD.The main routes of elimination of EGFRTKIsare metabolism via the liver,and renal elimination is minor.Therecommended doses and pharmacokinetics of these EGFR-TKIs for patientsundergoing HD are similar to those for patients with normal renal function.Theplasma protein binding of EGFR-TKIs is very high,and it is not necessary toadjust the dose after HD.In conclusion,EGFR-TKIs are effective and welltolerated in patients undergoing HD.

Is there a role for epidermal growth factor receptor tyrosine kinase inhibitors in epidermal growth factor receptor wildtype non-small cell lung cancer?

Non-small cell lung cancer(NSCLC) is the most common type of lung cancer with a world-wide annual incidence of around 1.3 million. The majority of patients arediagnosed with advanced disease and survival remains poor. However, relevant advances have occurred in recent years through the identification of biomarkers that predict for benefit of therapeutic agents. This is exemplified by the efficacy of epidermal growth factor receptor(EGFR) tyrosine kinase inhibitors for the treatment of EGFR mutant patients. These drugs have also shown efficacy in unselected populations but this point remains controversial. Here we have reviewed the clinical data that demonstrate a small but consistent subgroup of EGFR wild-type patients with NSCLC that obtain a clinical benefit from these drugs. Moreover, we review the biological rationale that may explain this benefit observed in the clinical setting.

New era of epidermal growth factor receptor-tyrosine kinase inhibitors for lung cancer

Lung cancer is the leading cause of death globally, besides recent advances in its management; it maintains a low 5-year survival rate of 15%. The discovery of epidermal growth factor receptor(EGFR) activating mutations and the introduction of its tyrosine kinase inhibitors(TKIs) have expanded the treatment options for patients with non-small cell lung cancer. Nowadays, EGFR mutation testing is now a common routine for newly diagnosed lung cancer. First generation TKIs developed, erlotinib and gefitinib, were reversible ones. After a median of 14 mo, eventually all EGFR mutated patients develop resistance to reversible TKIs. Afatinib, dacomitinib and neratinib, second generation inhibitors, are selective and irreversible TKIs. Finally, third generation phase Ⅰclinical trials were performed, with lower toxicity profiles, and targeting with more precision the driving clone of this heterogeneous disease.

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.

Coexistence of anaplastic lymphoma kinase rearrangement in lung adenocarcinoma harbouring epidermal growth factor receptor mutation:A single-center study

BACKGROUND Accumulating evidences confirm that epidermal growth factor receptor(EGFR)mutation and anaplastic lymphoma kinase(ALK)rearrangement have coexisted in lung adenocarcinoma(LUAD).However,Its biological mechanism,clinicopathological features,and optimization of targeted drugs have not yet been completely elucidated.AIM To explore the clinical profile of LUAD patients with co-mutations of EGFR and ALK genes,with hopes of scientifically guiding similar patients towards selected,targeted drugs.METHODS Two hundred and thirty-seven LUAD patients were enrolled.EGFR mutations were detected by the amplification refractory mutation system-peptide nucleic acid technique,while the expression of ALK rearrangement was screened by the 5′/3′imbalance strategy for reverse transcription followed by quantitative polymerase chain reaction analysis.The clinicopathological features of these patients were analysed retrospectively,and the follow-up data were collected.RESULTS There were six cases with co-mutations of EGFR and ALK genes,which were more common in women,non-smoking and stage IV LUAD patients with bone metastasis,hence a positive rate of 2.53%(6/237).EGFR-tyrosine kinase inhibitors(EGFR-TKIs)were their preferred drugs for targeted therapy in these patients,with progression-free survival ranging from two months to six months.CONCLUSION In Gannan region,the positive rate of co-mutations of EGFR and ALK genes in LUAD patients is relatively high,and the co-mutations are more common in women,non-smoking and stage IV patients with bone metastasis.These patients prefer EGFR-TKIs as their preferred targeted drugs,but the therapeutic effect is not good.EGFR/ALK dual-TKIs may be more effective targeted drugs,which needs further study.

Repurposed anti-cancer epidermal growth factor receptor inhibitors: mechanisms of neuroprotective effects in Alzheimer’s disease

Numerous molecular mechanisms are being examined in an attempt to discover disease-modifying drugs to slow down the underlying neurodegeneration in Alzheimer’s disease.Recent studies have shown the beneficial effects of epidermal growth factor receptor inhibitors on the enhancement of behavioral and pathological sequelae in Alzheimer’s disease.Despite the promising effects of epidermal growth factor receptor inhibitors in Alzheimer’s disease,there is no irrefutable neuroprotective evidence in well-established animal models using epidermal growth factor receptor inhibitors due to many un-explored downstream signaling pathways.This caused controversy about the potential involvement of epidermal growth factor receptor inhibitors in any prospective clinical trial.In this review,the mystery beyond the under-investigation of epidermal growth factor receptor in Alzheimer’s disease will be discussed.Furthermore,their molecular mechanisms in neurodegeneration will be explained.Also,we will shed light on SARS-COVID-19 induced neurological manifestations mediated by epidermal growth factor modulation.Finally,we will discuss future perspectives and under-examined epidermal growth factor receptor downstream signaling pathways that warrant more exploration.We conclude that epidermal growth factor receptor inhibitors are novel effective therapeutic approaches that require further research in attempts to be repositioned in the delay of Alzheimer’s disease progression.

JAK3 inhibitor Ⅵ is a mutant specific inhibitor for epidermal growth factor receptor with the gatekeeper mutation T790M

AIM:To identify non-quinazoline kinase inhibitors effective against drug resistant mutants of epidermal growth factor receptor(EGFR).METHODS:A kinase inhibitor library was subjected to screening for specific inhibition pertaining to the in vitro kinase activation of EGFR with the gatekeeper mutation T790 M,which is resistant to small molecular weight tyrosine kinase inhibitors(TKIs) for EGFR in nonsmall cell lung cancers(NSCLCs). This inhibitory effect was confirmed by measuring autophosphorylation of EGFR T790M/L858 R in NCI-H1975 cells,an NSCLC cell line harboring the gatekeeper mutation. The effects of a candidate compound,Janus kinase 3(JAK3) inhibitor Ⅵ,on cell proliferation were evaluated using the MTT assay and were compared between T790M-positive and-negative lung cancer cell lines. JAK3 inhibitor Ⅵ was modeled into the ATP-binding pocket of EGFR T790M/L858 R. Potential physical interactions between the compound and kinase domains of wild-type(WT) or mutant EGFRs or JAK3 were estimated by calculating binding energy. The gatekeeper residues of EGFRs and JAKs were aligned to discuss the similarities among EGFR T790 M and JAKs. RESULTS:We found that JAK3 inhibitor Ⅵ,a known inhibitor for JAK3 tyrosine kinase,selectively inhibits EGFR T790M/L858 R,but has weaker inhibitory effects on the WT EGFR in vitro. JAK3 inhibitor Ⅵ also specifically reduced autophosphorylation of EGFR T790M/L858 R in NCI-H1975 cells upon EGF stimulation,but did not show the inhibitory effect on WT EGFR in A431 cells. Furthermore,JAK3 inhibitor Ⅵ suppressed the proliferationof NCI-H1975 cells,but showed limited inhibitory effects on the WT EGFR-expressing cell lines A431 and A549.A docking simulation between JAK3 inhibitor Ⅵ and the ATP-binding pocket of EGFR T790M/L858 R predicted a potential binding status with hydrogen bonds. Estimated binding energy of JAK3 inhibitor Ⅵ to EGFR T790M/L858 R was more stable than its binding energy to the WT EGFR. Amino acid sequence alignments revealed that the gatekeeper residues of JAK family kinases are methionine in WT,similar to EGFR T790 M,suggesting that TKIs for JAKs may also be effective for EGFR T790 M. CONCLUSION:Our findings demonstrate that JAK3 inhibitor Ⅵ is a gatekeeper mutant selective TKI and offer a strategy to search for new EGFR T790 M inhibitors.

Effect of Zhiyang Pingfu Liquid on epidermal growth factor receptor inhibitor-related skin lesion

Objective:To verify the efficacy of the Chinese medicine“Zhiyang Pingfu Liquid”on the lesion associated with Epidermal Growth Factor Receptor Inhibitors(EGFRIs).Methods:Female BN rats were divided into Control group and Gefitinib group randomly.The Gefitinib group was administered gefitinib for 21 days.After 21 days,the rats in the Gefitinib group were grouped again and randomly divided into Model group,Gefitinib+ZY group,and Gefitinib+NS group.Starting from day 22,rats in Gefitinib+ZY or NS were given different drugs for 7 days besides the other conditions are as the same as before.Observe the morphological changes and histopathological changes of the skin during the research.The changes of inflammatory factors such as TNF-αand IL-6 in the serum of were detected by ELISA.Results:The application of“Zhiyang Pingfu Liquid”for 7 days could significantly reduce the skin inflammation whether in gross or pathological view.The concentration of TNF-αand IL-6 in Gefitinib+ZY is significantly lower than those in the Model group(P=0.002,P=0.002)and there is no significant changes compared with the Control group(P=0.279,P=0.165).Conclusion:Chinese herbal“Zhiyang Pingfu Liquid”can reduce the lesion and inflammatory caused by EGFRIs.

Epidermal growth factor receptor inhibitors in colorectal cancer treatment: What's new?

Colorectal cancer constitutes one of the most common malignancies and the second leading cause of death from cancer in the western world representing one million new cases and half a million deaths annually worldwide. The treatment of patients with metastatic colon cancer comprises different regimens of chemotherapeutic compounds (fluoropyrimidines, irinotecan and oxaliplatin) and new targeted therapies. Interestingly, most recent trials that attempt to expose patients to all five-drug classes (fluoropyrimidines, irinotecan, oxaliplatin, bevacizumab and cetuximab) achieve an overall survival well over 2 years. In this review we will focus on the main epidermal growth factor receptor inhibitors demonstrating clinical benefit for colorectal cancer mainly cetuximab, panitumumab, erlotinib and gefitinib. We will also describe briefly the molecular steps that lie beneath them and the different clinical or molecular mechanisms that are reported for resistance and response.

Associations Between Epidermal Growth Factor Receptor Gene Mutation and Serum Tumor Markers in Advanced Lung Adenocarcinomas: A Retrospective Study

Objective To investigate the associations between epidermal growth factor receptor(EGFR) gene mutations and serum tumor markers in advanced lung adenocarcinomas. Methods We investigated the association between EGFR gene mutations and clinical features, including serum tumor marker levels, in 97 advanced lung adenocarcinomas patients who did not undergo the treatment of EGFR tyrosine kinase inhibitors. EGFR gene mutation was detected by real-time PCR at exons 18, 19, 20, and 21. Serum tumor marker concentrations were analyzed by chemiluminescence assay kit at the same time. Results EGFR gene mutations were detected in 42(43%) advanced lung adenocarcinoma patients. Gender(P=0.003), smoking status(P=0.001), and abnormal serum status of carcinoembryonic antigen(CEA, P=0.028) were significantly associated with EGFR gene mutation incidence. Multivariate analysis showed the abnormal CEA level in serum was independently associated with the incidence of EGFR gene mutation(P=0.046) with an odds ratio of 2.613(95% CI: 1.018-6.710). However, receiver operating characteristic(ROC) curve analysis revealed CEA was not an ideal predictive marker for EGFR gene mutation status in advanced lung adenocarcinoma(the area under the ROC curve was 0.608, P=0.069). Conclusions EGFR gene mutation status is significantly associated with serum CEA status in advanced lung adenocarcinmoas. However, serum CEA is not an ideal predictor for EGFR mutation.

Recent advances and new insights in the management of early-stage epidermal growth factor receptor-mutated non-small-cell lung cancer

Patients with early-stage non-small-cell lung cancer(NSCLC)are candidates for curative surgery;however,despite multiple advances in lung cancer management,recurrence rates remain high.Adjuvant chemotherapy has been demonstrated to significantly prolong overall survival(OS),but this benefit is modest and there is an urgent need for effective new therapies to provide a cure for more patients.The high efficacy of tyrosine kinase inhibitors(TKIs)against epidermal growth factor receptor-mutated(EGFR)in patients with advanced EGFR-mutated NSCLC has led to the evaluation of these agents in early stages of the disease.Multiple clinical trials have evaluated the safety and efficacy of EGFR TKIs as an adjuvant treatment,in patients with resected EGFR-mutated NSCLC,and shown that they significantly prolong disease-free survival(DFS),but this benefit does not translate to OS.Recently,an interim analysis of the ADAURA trial demonstrated that,surprisingly,osimertinib improved DFS.This led to the study being stopped early,leaving many unanswered questions about its potential effect on OS and its incorporation as a standard adjuvant treatment in this patient subgroup.These targeted agents are also being evaluated in locally-advanced disease,with promising results,although prospective studies with larger sample sizes are needed to confirm these results.In this article,we review the most relevant studies on the role of EGFR TKIs in the management of early-stage EGFR-mutated NSCLC.

Treatment of gastrointestinal neuroendocrine tumors with inhibitors of growth factor receptors and their signaling pathways: Recent advances and future perspectives

The limited efficacy of conventional cytotoxic treatment regimes for advanced gastrointestinal neuroendocrine cancers emphasizes the need for novel and more effective medical treatment options. Recent findings on the specific biological features of this family of neoplasms has led to the development of new targeted therapies, which take into account the high vascularization and abundant expression of specific growth factors and cognate tyrosine kinase receptors. This review will briefly summarize the status and future perspectives of antiangiogenic, mTOR- or growth factor receptor-based pharmacological approaches for the innovative treatment of gastrointestinal neuroendocrine tumors. In view of the multitude of novel targeted approaches, the rationale for innovative combination therapies, i.e. combining growth factor (receptor)-targeting agents with chemo- or biotherapeutics or with other novel anticancer drugs such as HDAC or proteasome inhibitors will be taken into account.

Phase I trial of icotinib, a novel epidermal growth factor receptor tyrosine kinase inhibitor, in Chinese patients with non-small cell lung cancer

Background The preclinical experiments and studies of congener drugs show icotinib, a new epidermal growth factor receptor （EGFR） tyrosine kinase inhibitor, can specifically bind to the tyrosine kinase domain of the EGFR, block the EGFR related signal, thereby inhibit the growth of tumor cell. The objective of this study was to investigate the safety, tolerability and dose-related biologic effects of icotinib in patients with non-small cell lung cancer （NSCLC） in a Chinese patient population. Methods This was an open-label, phase I, dose escalation, safety/tolerability trial of oral icotinib （100 to 400 mg）, administered twice per day for 28-continuous-day cycles until disease progression or undue toxicity. Results Forty patients with stage IIIB （15%） or IV （85%） NSCLC were included in the study. They had mainly adenocarcinoma （85%）, with a performance status （PS） of 0 （45%） or 1 （55%） and less than half the patients （45%） had histories of smoking and all were pretreated by at least one regimen of chemotherapy. Patients were assigned to three dose levels of 150 mg b.i.d, 200 mg b.i.d, or 125 mg t.i.d. The follow-up periods ranged from 5 to 80 weeks. Adverse events were found in 35% patients, most of which were mild and reversible. The adverse events mainly occurred in the first 4 weeks and included rash （25%）, diarrhea, nausea and abdominal distention. One definite interstitial lung disease （ILD） was found in a patient in the dose of 200 mg b.i.d. According to an 8-week assessment, one （2.5%） patient receiving 150 mg gained complete response （CR） that persisted for 44 weeks, seven （17.50%） patients had partial remission （PR）, and 18 （45%） patients had stable disease （SD）. The objective response including CR＋PR was 20%. The median time of progression-free survival for the 40 patients was 20 weeks （range： 12 to 32 weeks）. The response was not affected by pathological type, history of smoking, or numbers of previous therapeutic regimens. No relationship between dose, response, adverse effect, or duration of the study was observed. Conclusions Icotinib, given as oral twice daily, showed favorable safety and tolerability. Mild and reversible rash, diarrhea, and nausea were the main adverse events. Antitumor activity was obvious at each dose in heavily pretreated patients. Pharmacodynamic evaluations and further phase II/III trials are in progress.

Management of tyrosine kinase inhibitor resistance in lung cancer with EGFR mutation

The identification of driver mutations and drugs that inhibit their activity has been a major therapeutic advance for patients with advanced lung adenocarcinoma. Unfortunately, the success of these drugs is limited by the universal development of resistance. Treatment failure can result from inadequate drug exposure or selection of resistant malignant clones. Clinically distinct mechanisms of disease progression have been identified and can inform treatment decisions. Investigations into the biochemical mechanisms of tyrosine kinase inhibitor resistance may provide additional therapeutic targets by which the efficacy of targeted therapy can be improved.

A candidate targeting molecule of insulin-like growth factor-Ⅰ receptor for gastrointestinal cancers

Advances in molecular research in cancer have brought new therapeutic strategies into clinical usage.One new group of targets is tyrosine kinase receptors,which can be treated by several strategies,including small molecule tyrosine kinase inhibitors(TKIs) and monoclonal antibodies(mAbs).Aberrant activation of growth factors/receptors and their signal pathways are required for malignant transformation and progression in gastrointestinal(GI) carcinomas.The concept of targeting specif ic carcinogenic receptors has been validated by successful clinical application of many new drugs.Type I insulin-like growth factor(IGF) receptor(IGF-IR) signaling potently stimulates tumor progression and cellular differentiation,and is a promising new molecular target in human malignancies.In this review,we focus on this promising therapeutic target,IGF-IR.The IGF/IGF-IR axis is an important modifier of tumor cell proliferation,survival,growth,and treatment sensitivity in many malignant diseases,including human GI cancers.Preclinical studies demonstrated that downregulation of IGF-IR signals reversed the neoplastic phenotype and sensitized cells to anticancer treatments.These results were mainly obtained through our strategy of adenoviruses expressing dominant negative IGF-IR(IGF-IR/dn) against gastrointestinal cancers,including esophagus,stomach,colon,and pancreas.We also summarize a variety of strategies to interrupt the IGFs/IGF-IR axis and their preclinical experiences.Several mAbs and TKIs targeting IGF-IR have entered clinical trials,and early results have suggested that these agents have generally acceptable safety profiles as single agents.We summarize the advantages and disadvantages of each strategy and discuss the merits/demerits of dual targeting of IGF-IR and other growth factor receptors,including Her2 and the insulin receptor,as well as other alternatives and possible drug combinations.Thus,IGF-IR might be a candidate for a molecular therapeutic target in human GI carcinomas.

Tyrosine kinase inhibitors:Multi-targeted or single-targeted?

Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL,SCR,platelet derived growth factor,vascular endothelial growth factor receptor and epidermal growth factor receptor families.Both multi-kinase inhibitors and singlekinase inhibitors have advantages and disadvantages,which are related to potential resistance mechanisms,pharmacokinetics,selectivity and tumor environment.In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist.Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor.Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity,while differences in gene expression exist between tumor and stromal cells.Considering these aspects,one type of inhibitor can generally not be preferred above the other,but will depend on the specific genetic constitution of the patient and the tumor,allowing personalized therapy.The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered(epi)genetics of the tumor.This strategy might result in treatment by a single multi kinase inhibitor for one patient,but in treatment by a couple of single kinase inhibitors for other patients.

The relationship between tyrosine kinase inhibitor therapy and overall survival in patients with non-small cell lung cancer carrying EGFR mutations

For patients with epidermal growth factor receptor (EGFR) mutation-positive lung cancer, the relationship between the dose or duration of treatment with tyrosine kinase inhibitor (TKI) and overall survival remains unclear. Here, we analyzed clinical data of 39 patients who were diagnosed with EGFR mutation-positive non-small cell lung cancer and treated with TKI, but subsequently died. Several parameters were measured in this study: overall survival; first, second, and overall TKI therapy durations; first TKI intensity (actual dose/normal dose); and TKI rate (overall TKI therapy duration/overall survival). The response rate to TKI therapy was 50% , and the median survival was 553 days. After TKI therapy failed, 38.5% patients were re-challenged with TKI. We observed a moderate relationship [r = 0.534, 95% confidential interval (CI) = 0.263 to 0.727, P < 0.001] between overall TKI therapy duration and overall survival. However, we found no relationship between overall survival and first TKI intensity (r = 0.073, 95% CI = -0.380 to 0.247, P = 0.657) or TKI rate (r = 0.0345, 95% CI = -0.284 to 0.346, P = 0.835). Nonsmall cell lung cancer patients with mutation-positive tumors remained on TKI therapy for, on average, 33% of the overall survival time. These findings suggest that patients with EGFR mutation-positive tumors should not stick to using TKIs.