Critical update and emerging trends in epidermal growth factor receptor targeting in cancer

Clinicopathological and prognostic significances of EGFR, KRAS and BRAF mutations in biliary tract carcinomas in Taiwan

BACKGROUND AND AIM

Biliary tract carcinomas (BTCs) are difficult to diagnose and treat. Epidermal growth factor receptor (EGFR) represents a therapeutic target for the BTCs. Mutations of the EGFR gene and the activation of its downstream pathways, including KRAS and BRAF, predict the sensitivity to anti-EGFR treatment. The aims of this study were to analyze the EGFR, KRAS and BRAF mutations in BTCs and their association with clinical outcomes.

METHODS

Paraffin-embedded specimens containing 137 BTCs resected at the National Taiwan University Hospital between 1995 and 2004 were analyzed. The exons 18-21 of EGFR gene, the codon 12, 13 and 61 of KRAS gene, and BRAF V600E mutation were analyzed. We examined the correlation between these mutations and the overall survival, tumor location, stage, and differentiation in BTCs.

RESULTS

Thirteen (9.5%) BTC patients had EGFR mutations while 23 (16.8%) patients had KRAS mutations. Only one patient had BRAF mutation. Factors influencing survival on univariate analysis were tumor stage, tumor differentiation, and EGFR mutation. On multivariate analysis, EGFR mutation and tumor stage were independent prognostic factors. A correlation between KRAS or BRAF mutations and prognosis was not observed.

CONCLUSIONS

EGFR and KRAS mutations are not uncommon in BTCs. BRAF mutation is rare in BTCs. EGFR mutation was an independent prognostic marker in BTCs in addition to tumor stage and differentiation. No simultaneous EGFR and KRAS mutations in extrahepatic cholangiocarcinoma and gallbladder carcinoma were found. EGFR and KRAS mutations should be evaluated when tailoring molecular-targeted therapy to patients with BTCs.

Effects of pemetrexed, gefitinib, and their combination on human colorectal cancer cells

PURPOSE

The study investigated the effects of pemetrexed, gefitinib, and their combination on human colorectal cancer cells.

METHODS

Six human colorectal cancer cells were exposed to pemetrexed, gefitinib, and their combination. Antitumor effects were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Thymidylate synthase (TS) mRNA expression and EGFR mutation were studied by real-time RT-PCR and DNA sequence determination. Pharmacological interaction was studied using the combination index method. Cell cycle distribution and apoptosis were determined by flow cytometry. Activity assay was performed to assess the effects of drugs on TS activity, and Western blot was performed to assess the protein expression of pEGFR, pAKT, and pERK 1/2.

RESULTS

Six colorectal cancer cells are all sensitive to pemetrexed, and TS gene expression of cells was negatively related to pemetrexed sensitivity. The cytotoxic synergism was observed in concurrent pemetrexed combined with gefitinib and sequential pemetrexed followed by gefitinib. The combination of pemetrexed and gefitinib modulated cell cycle and induced apoptosis. Pemetrexed combined with gefitinib decreased TS mRNA expression and in situ activity. Pemetrexed induced an EGFR-mediated activation of the phosphatidylinositol 3-kinase/AKT and ERK pathway, which was inhibited by gefitinib.

CONCLUSIONS

Pemetrexed is a promising agent, and pemetrexed combined with gefitinib has a significantly synergistic effect on colorectal cancer cells, which seems to present a strategy of pemetrexed combined with EGFR-TKIs in colorectal cancer treatment.

EGFR gene copy number as a predictive biomarker for resistance to anti-EGFR monoclonal antibodies in metastatic colorectal cancer treatment: a meta-analysis

OBJECTIVE

The epidermal growth factor receptor (EGFR) inhibitors monoclonal antibodies (MoAbs) have already shown the therapeutic effectiveness in patients with metastatic colorectal cancer (mCRC). But many patients resist to the treatment. The aim of this meta-analysis was to assess EGFR gene copy number (GCN) as a candidate predictive biomarker for resistance to anti-EGFR MoAbs in mCRC treatment.

METHODS

Systematic computerized searches of the PubMed, EMBase and Cochrane Library were performed. The primary endpoint was objective response rate (ORR). The second endpoints included progression-free survival (PFS), and overall survival (OS). The pooled odd ratio (OR) and pooled sensitivity, specificity, and summary receiver operator characteristic (SROC) for ORR were estimated. The pooled hazard ratios (HR) for PFS and OS were also calculated.

RESULTS

Fourteen studies with 1,021 patients were included. Increased EGFR GCN was associated with increased ORR (OR=6.905; 95% CI: 4.489-10.620). It was also found in wild-type KRAS mCRC patients, with the pooled OR of 8.133 (95% CI: 4.316-15.326). GCN has medium value for predicting ORR, with the pooled sensitivity of 0.79 (95% CI: 0.73-0.84), the pooled specificity of 0.59 (95% CI: 0.55-0.62). In wild-type KRAS mCRC patients, the sensitivity and the specificity were 0.80 (95% CI: 0.70-0.87) and 0.60 (95% CI: 0.53-0.66), respectively. Increased EGFR GCN was associated with increased PFS (HR=0.557; 95% CI: 0.382-0.732) and OS (HR=0.579; 95% CI: 0.422-0.737).

CONCLUSIONS

This meta-analysis suggests that EGFR GCN represents a predictive biomarker for tumor response in mCRC patients treated with MoAbs regardless of KRAS mutation. mCRC patients with increased EGFR GCN are more likely to have a better response, PFS, and OS when treated with cetuximab or panitumumab.

Phase 2 trial of erlotinib combined with cisplatin and radiotherapy in patients with locally advanced cervical cancer

BACKGROUND

Cisplatin-based chemoradiation (CRT) is the standard treatment for patients with locally advanced cervical cancer. Epidermal growth factor receptor (EGFR) is frequently overexpressed in cervical cancer, and EGFR inhibition itself has antitumor effects and potentiates CRT. Results of a previous phase 1 trial of the EGFR inhibitor erlotinib combined with cisplatin-based CRT (E + CRT) recommended a phase 2 erlotinib dose of 150 mg/day.

METHODS

Eligibility criteria included International Federation of Gynecology and Obstetrics stage IIB to IIIB epidermoid cervical cancer, no prior therapy, and an Eastern Cooperative Oncology Group performance status of 0 to 2. Patients received erlotinib at a dose of 150 mg/day 1 week before and in combination with cisplatin (40 mg/m(2) administered weekly for 5 cycles) and radiotherapy (4500 centigrays in 25 fractions), followed by brachytherapy (4 fractions at a dose of 600 centigrays weekly).

RESULTS

A total of 36 patients completed treatment with E + CRT. The median duration of therapy was 77 days and the median follow-up period was 59.3 months. The therapy was well tolerated overall, and 34 patients (94.4%) achieved a complete response. The 2-year and 3-year cumulative overall and progression-free survival rates were 91.7% and 80.6% and 80% and 73.8%, respectively.

CONCLUSIONS

Treatment with E + CRT appears to be safe and exerts significant activity against locally advanced cervical cancer. To the best of the authors' knowledge, this is the first study to date to demonstrate that a target agent has promising activity against locally advanced cervical cancer.

Novel mechanistic insights into ectodomain shedding of EGFR Ligands Amphiregulin and TGF-α: impact on gastrointestinal cancers driven by secondary bile acids

Secondary bile acids (BA) such as deoxycholic acid (DCA) promote the development of several gastrointestinal malignancies, but how they mediate this effect is unclear. In this study, we offer evidence of a mechanism involving ectodomain shedding of the EGFR ligands amphiregulin (AREG) and TGF-α, which rely upon the cell surface protease TACE/ADAM-17. Specifically, we show that AREG participates in DCA-induced EGFR and STAT3 signaling, cell-cycle progression, and tumorigenicity in human colorectal cancer and pancreatic ductal adenocarcinoma (PDAC). TACE and AREG, but not TGF-α, were overexpressed in both colorectal cancer and PDAC tissues compared with normal tissues. Exposure of colorectal cancer and PDAC cells to DCA resulted in colocalization of Src and TACE to the cell membrane, resulting in AREG-dependent activation of EGFR, mitogen-activated protein kinase (MAPK), and STAT3 signaling. Src or TACE inhibition was sufficient to attenuate DCA-induced AREG, but not TGF-α shedding. We also examined a role for the BA transporter TGR5 in DCA-mediated EGFR and STAT3 signaling. RNA interference-mediated silencing of TGR5 or AREG inhibited DCA-induced EGFR, MAPK, and STAT3 signaling, blunted cyclin D1 expression and cell-cycle progression, and attenuated DCA-induced colorectal cancer or PDAC tumorigenicity. Together, our findings define an AREG-dependent signaling pathway that mediates the oncogenic effects of secondary BAs in gastrointestinal cancers, the targeting of which may enhance therapeutic responses in their treatment.

Targeting epidermal growth factor receptor signaling in the treatment of head and neck cancer

In this review, key aspects of epidermal growth factor receptor (EGFR) biology and the fruitful translation of these fundamental findings into recent treatment advances in head and neck squamous cell cancer (HNSCC) are highlighted. In contrast to a number of contemporary reviews of the EGFR, many of which focus on colorectal and nonsmall cell lung cancer, this review discusses the EGFR as a validated therapeutic target in HNSCC. Recent data confirm a survival advantage for the addition of the anti-EGFR monoclonal antibody cetuximab to definitive radiation therapy in locoregionally advanced HNSCC patients, as well as palliative benefits for patients with incurable recurrent and metastatic HNSCC. Small-molecule EGFR tyrosine kinase inhibitors also show considerable promise in this disease, both alone and in combination with radiation and chemotherapy. Both classes of anti-EGFR agent are generally well tolerated, with side effects (notably skin rash) that are distinct from the toxicities of conventional chemotherapy. Ongoing clinical trials will more clearly define the role for EGFR inhibitors in all treatment phases of HNSCC.

Pancreatic cancer: role of the immune system in cancer progression and vaccine-based immunotherapy

Pancreatic cancer (PC) is the 5th leading cause of cancer related death in the developed world with more than 260,000 deaths annually worldwide and with a dismal 5-year survival. Surgery is the only potential hope of cure for PC, but, unfortunately, only 20% PC patients is resectable at the time of diagnosis. Therapeutic research efforts have mainly focused on improvements in radio/ chemo treatments and to date, there are only a few chemotherapeutic agents that have shown to be effective against PC, including gemcitabine with or without abraxane as well as a combination of 5-FU, leucovorin, oxaliplatin and irinotecan (the so-called FOLFIRINOX regimen). The survival of patients treated with these regimens is marginal and hence we are in urgent need of novel therapeutic approaches to treat pancreatic cancer. The success of immunotherapeutic strategies in other cancers and various evidences that pancreatic adenocarcinoma elicits antitumor immune responses, suggest that immunotherapies can be a promising alternative treatment modality for this deadly disease. PC immunotherapy treatments include passive immunotherapeutic approaches, such as the use of effector cells generated in vitro, and active immunotherapeutic strategies, which goal is to stimulate an antitumor response in vivo, by means of vaccination. In this review, we describe the immune suppressive mechanisms of pancreatic cancer and discuss recent preclinical and clinical efforts toward PC immunotherapy, including passive approaches, such as the use of antibodies and active strategies (vaccination), with a special mention of most recent treatment with CRS-207 and GVAX.

Synergistic antitumor activity of cetuximab and namitecan in human squamous cell carcinoma models relies on cooperative inhibition of EGFR expression and depends on high EGFR gene copy number

PURPOSE

Despite the frequent overexpression of epidermal growth factor receptor (EGFR) in squamous cell carcinoma (SCC), the efficacy of cetuximab alone is limited. Given the marked activity of namitecan, a hydrophilic camptothecin, against SCC models, the present study was performed to explore the efficacy of the cetuximab-namitecan combination in a panel of SCC models.

EXPERIMENTAL DESIGN

We examined the antiproliferative and antitumor activities of the cetuximab-namitecan combination in four SCC models characterized by a different EGFR gene copy number/EGFR protein level. We also assessed the effects of the combination on EGFR expression at both mRNA and protein levels and investigated the molecular basis of the interaction between the two agents.

RESULTS

Cetuximab and namitecan exhibited synergistic effects, resulting in potentiation of cell growth inhibition and, most importantly, enhanced therapeutic efficacy, with high cure rates in three SCC models characterized by high EGFR gene copy number, without increasing toxicity. The synergistic antitumor effect was also observed with the cetuximab-irinotecan combination. At the molecular level, the two agents produced a cooperative effect resulting in complete downregulation of EGFR. Interestingly, when singly administered, the camptothecin was able to strongly decrease EGFR expression mainly by transcriptional inhibition.

CONCLUSIONS

Our results (i) demonstrate a marked efficacy of the cetuximab-namitecan combination, which reflects a complete abrogation of EGFR expression as a critical determinant of the therapeutic improvement, in SCC preclinical models, and (ii) suggest EGFR gene copy number as a possible marker to be used for patient selection in the clinical setting.

MUC15 inhibits dimerization of EGFR and PI3K-AKT signaling and is associated with aggressive hepatocellular carcinomas in patients

BACKGROUND & AIMS

Aberrant expression of MUC15 correlates with development of colorectal adenocarcinoma, and MUC15 has been reported to prevent trophoblast invasion of human placenta. However, little is known about the role of MUC15 in pathogenesis of hepatocellular carcinoma (HCC).

METHODS

We analyzed HCC samples and matched nontumor liver tissues (controls) collected from 313 patients who underwent hepatectomy in Shanghai, China, from January 2006 through September 2009. Levels of messenger RNAs and proteins were determined by immunohistochemical, quantitative reverse transcription polymerase chain reaction, and immunoblot analyses. Statistical analyses were used to associate levels of MUC15 with tumor features and patient outcomes.

RESULTS

Levels of MUC15 messenger RNA and protein were reduced in a greater percentage of HCC samples than control tissues. Tumors with reduced levels of MUC15 were more likely to have aggressive characteristics (eg, high levels of α-fetoprotein, vascular invasion, lack of encapsulation, and poor differentiation) than those with low levels. Patients whose tumors had reduced levels of MUC15 had shorter overall survival times (24 months vs 46 months for patients with tumors with high levels of MUC15) and time to disease recurrence. Stable expression of MUC15 in HCC cell lines (SMMC-7721 and HCC-LM3) reduced their proliferation and invasive features in vitro, and ability to form metastatic tumors in mice. MUC15 reduced transcription of the matrix metalloproteinases 2 and 7 increased expression of tissue inhibitor of metalloproteinase-2, which required phosphoinositide 3-kinase-v-akt murine thymoma viral oncogene homolog signaling. Physical interaction between MUC15 and epidermal growth factor receptor led to its relocation and degradation within early endosomes and was required for inactivation of phosphoinositide 3-kinase-v-akt murine thymoma viral oncogene homolog signaling.

CONCLUSIONS

Reduced levels of MUC15 in HCCs are associated with shorter survival times of patients and reduced time to disease recurrence. Expression of MUC15 in HCC cells reduces their aggressive behavior in vitro and in mice by inducing dimerization of epidermal growth factor receptor and decreasing phosphoinositide 3-kinase signaling via v-akt murine thymoma viral oncogene homolog.

New targets in non-small cell lung cancer

Lung cancer remains the most common cause of cancer-related death in the United States. At presentation, the majority of patients have regional or systemic metastases and therefore require systemic therapy. For years, chemotherapy was the only systemic therapy option. A major paradigm shift has occurred in recent years with the identification of driver genetic alterations in some non-small cell lung cancers (NSCLCs). It is part of current standard of care to assess epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) translocations in tumors of patients with advanced NSCLC. Drugs targeting these mutations provide significant clinical benefit and are the preferred therapeutic option in these patients. Ongoing clinical trials are assessing the clinical benefit from targeting other driver genetic alterations. Further therapeutic targets have been identified through greater understanding of the variety of molecular processes that facilitate tumor formation and progression. Some of these new therapeutic targets are heat shock proteins and targets that can allow enhanced anti-tumor immune response. It is expected that these advances will allow personalized management of NSCLC patients and move us away from approaching all NSCLC patients with the same therapeutic tools.

EGFR and microvessel density in canine malignant mammary tumours

The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor which has been shown to have an important role in human breast cancer. Its role appears to be associated with increased angiogenesis and metastasis. In order to clarify its role in canine mammary tumours (CMT), 61 malignant neoplasms were studied by using immunohistochemistry, comparing expression of EGFR, microvessel density (MVD) by CD31 immunolabelling and characteristics of tumour aggressiveness. High EGFR immunoexpression was statistically significantly associated with tumour size, tumour necrosis, mitotic grade, histological grade of malignancy and clinical stage. High CD31 immunoreactivity was statistically significantly associated with tubule formation, histological grade of malignancy and clinical stage. A positive correlation between EGFR and CD31 immunoexpression (r = 0.843; P < 0.001) was also observed. Results suggest that an over-expression of EGFR may contribute to increased angiogenesis and aggression in malignant CMT, presenting the possibility of using EGFR inhibitors in the context of metastatic disease treatment.

Imaging EGFR and HER2 by PET and SPECT: a review

In an effort to discover a noninvasive method for predicting which cancer patients will benefit from therapy targeting the EGFR and HER2 proteins, a large body of the research has been conducted toward the development of PET and SPECT imaging agents, which selectively target these receptors. We provide a general overview of the advances made toward imaging EGFR and HER2, detailing the investigation of PET and SPECT imaging agents ranging in size from small molecules to monoclonal antibodies.

A multicenter phase II study of cetuximab in combination with chest radiotherapy and consolidation chemotherapy in patients with stage III non-small cell lung cancer

BACKGROUND

Cetuximab has demonstrated improved efficacy in combination with chemotherapy and radiotherapy. We evaluated the integration of cetuximab in the combined modality treatment of stage III non-small cell lung cancer (NSCLC).

METHODS

Patients with surgically unresectable stage IIIA or IIIB NSCLC were treated with chest radiotherapy, 73.5 Gy (with lung and tissue heterogeneity corrections) in 35 fractions/7 weeks, once daily (63 Gy without heterogeneity corrections). Cetuximab was given weekly during radiotherapy and continued during consolidation therapy with carboplatin and paclitaxel up to a maximum of 26 weekly doses. The primary endpoint was overall survival. Baseline tumor tissue was analyzed for EGFR by fluorescence in situ hybridization (FISH).

RESULTS

Forty patients were enrolled in this phase II study. The median overall survival was 19.4 months and the median progression-free survival 9.3 months. The best overall response rate in 31 evaluable patients was 67%. No grade 3 or 4 esophagitis was observed. Three patients experienced grade 3 rash; 16 patients (69%) developed grade 3/4 neutropenia during consolidation therapy. One patient died of pneumonitis, possibly related to cetuximab. EGFR gene copy number on baseline tumor tissues, analyzed by FISH, was not predictive of efficacy outcomes.

CONCLUSIONS

The addition of cetuximab to chest radiotherapy and consolidation chemotherapy was tolerated well and had modest efficacy in stage III NSCLC. Taken together with the lower incidence of esophagitis, our results support evaluation of targeted agents instead of chemotherapy with concurrent radiotherapy in this setting.

Structural evaluation of EGFR inhibition mechanisms for nanobodies/VHH domains

The epidermal growth factor receptor (EGFR) is implicated in human cancers and is the target of several classes of therapeutic agents, including antibody-based drugs. Here, we describe X-ray crystal structures of the extracellular region of EGFR in complex with three inhibitory nanobodies, the variable domains of heavy chain only antibodies (VHH). VHH domains, the smallest natural antigen-binding modules, are readily engineered for diagnostic and therapeutic applications. All three VHH domains prevent ligand-induced EGFR activation, but use two distinct mechanisms. 7D12 sterically blocks ligand binding to EGFR in a manner similar to that of cetuximab. EgA1 and 9G8 bind an epitope near the EGFR domain II/III junction, preventing receptor conformational changes required for high-affinity ligand binding and dimerization. This epitope is accessible to the convex VHH paratope but inaccessible to the flatter paratope of monoclonal antibodies. Appreciating the modes of binding and inhibition of these VHH domains will aid in developing them for tumor imaging and/or cancer therapy.

Phase I study of pulsatile 3-day administration of afatinib (BIBW 2992) in combination with docetaxel in advanced solid tumors

BACKGROUND

A phase I study to assess the maximum tolerated dose (MTD) of a short course of afatinib in combination with docetaxel for the treatment of solid tumors.

METHODS

Patients with advanced solid malignancies received docetaxel 75 mg/m(2) intravenously on day 1 and oral afatinib once daily on days 2-4, in 3-week treatment cycles. The afatinib dose was escalated in successive cohorts of 3-6 patients until dose-limiting toxicity (DLT). The MTD cohort was expanded to 13 patients. Pharmacokinetic parameters were assessed.

RESULTS

Forty patients were treated. Afatinib doses were escalated to 160 mg/day in combination with 75 mg/m(2) docetaxel. Three patients had drug-related DLTs during cycle 1. The MTD was defined as 90 mg/day afatinib (days 2-4) with docetaxel 75 mg/m(2). The most frequent drug-related adverse events (all grades) were alopecia, diarrhea, stomatitis (all 50 %) and rash (40 %, all grade ≤ 2). Three patients had confirmed responses, two patients had unconfirmed responses and nine patients had durable stable disease >6 cycles. No pharmacokinetic interaction was observed.

CONCLUSION

Afatinib 90 mg administered for 3 days after docetaxel 75 mg/m(2) is the MTD for this treatment schedule and the recommended phase II/phase III dose. This combination showed anti-tumor activity in phase I, with a manageable adverse-event profile.

Lapatinib inhibits the growth of esophageal squamous cell carcinoma and synergistically interacts with 5-fluorouracil in patient-derived xenograft models

Lapatinib is a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and human EGFR-2 (HER2) tyrosine kinase domains. To explore the potential utility of lapatinib for the treatment of esophageal squamous cell carcinoma (ESCC), we examined the expression profiles of EGFR and HER2 in tumor tissues and in paired adjacent non-neoplastic tissues from patients with ESCC. We evaluated the antitumor effects of lapatinib alone or in combination with oxaliplatin or 5-fluorouracil (5-FU) on a panel of primary ESCC cells in vitro with various levels of EGFR and HER2 expression. The in vivo effect of lapatinib alone or in combination with oxaliplatin or 5-FU was evaluated using a primary ESCC xenograft model. EGFR was overexpressed in 80.9% (76/94) of the ESCC samples, while 24.5% (23/94) of the samples overexpressed HER2. EGFR and HER2 co-overexpression was detected in 22.3% of samples (21/94). In vitro, the primary ESCC cells were more sensitive to lapatinib combined with 5-FU or oxaliplatin than to lapatinib alone. Lapatinib in combination with 5-FU had more potent antitumor effects in the primary ESCC xenograft model, and markedly reduced the phosphorylation of EGFR and HER2, compared with lapatinib alone or in combination with oxaliplatin. These data indicate that lapatinib has activity in EGFR- and/or HER2-expressing ESCC primary cells, and that lapatinib in combination with 5-FU may be a promising treatment strategy for patients with ESCC.

Gefitinib versus erlotinib as salvage treatment for lung adenocarcinoma patients who benefited from the initial gefitinib: A retrospective study

BACKGROUND

  The optimal strategy was not established for patients who initially responded to gefitinib although re-administration of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has been proven to be an option. Gefitinib and erlotinib were compared as salvage treatment after gefitinib failure.

METHODS

  Thirty-eight lung adenocarcinoma patients were analyzed retrospectively as they received the second EGFR-TKIs treatment with either gefitinib or erlotinib. All of them had obtained disease control from initial gefitinib. Sixteen patients received gefitinib (G-G group) and 22 patients received erlotinib (G-E group).

RESULTS

  Of all patients, progress free survival (PFS) and overall survival (OS) were three and 12 months, respectively, and the disease controlled rate (DCR) of the second EGFR-TKIs treatment was 52.6%. One patient (6.3%) had partial remission (PR) and 10 (62.5%) had stable disease (SD), in the G-G group, whereas, three (13.6%) had PR and six (27.2%) had SD, in the G-E group. There was no statistical significance observed, although the DCR in the G-G group was higher than that in G-E group (68.8% vs. 40.8%, P= 0.09). Adverse events of both gefitinib and erlotinib were mild and administered. The median PFS and OS in G-G and G-E groups were similar (PFS four vs. three months; OS 22 vs. 12 months). In multivariate analysis, patients with SD in initial gefitinib treatment had significantly longer OS (P= 0.04).

CONCLUSIONS

  Gefitinib as well as erlotinib could be an option for patients who benefited from prior gefitinib treatment. Patients with SD in initial gefitinib obtained a significantly longer OS than those with PR.

Is availability of anti-EGFR therapy for the colorectal adenocarcinomas showing fascin expression limited?

Colorectal adenocarcinoma (CRC) is a major cause of death. Fascin expression in CRCs was proved to be related with higher metastatic rates and poor prognosis, while metastatic patients with only wild type K-RAS gene are the candidates of recent molecularly targeted anti-epidermal growth factor receptor (EGFR) therapies. This study is designed to investigate the correlation between the fascin expression status and the K-RAS mutational status of CRCs in order to assess the availability rate of anti-EGFR therapies for patients with fascin-expressing CRCs. Immunohistochemical expression of fascin and mutational status of K-RAS were investigated in the archival materials of randomly selected 50 metastatic colorectal carcinoma patients. Strength of fascin expression and tumor percentage stained with fascin were scored semi quantitatively. c.34 > C (p.G12R), c.35 g > C (p.G12C), c.34G > A (p.G12S), c.35G > A (p.G12D), c.35G > T (p.G12V), c.35G > C (p.G12A), and c.38G > A (p.G13.D) mutations in K-RAS gene were studied by using RT-PCR. In immunohistochemical evaluation, 32 of the 50 cases stained positive with fascin, while 21 were positive for K-RAS mutations in codon 12 (10 patients) or in codon 13 (3 patients). The correlation between the positivity of fascin and the presence of K-RAS mutations, the strength of fascin staining and the presence of K-RAS mutations, and the tumor cell percentage stained with fascin and the presence of K-RAS mutations were found statistically significant. The results of this study suggest that patients with fascin-expressing CRCs have a greater tendency to carry an activating K-RAS mutation which will prevent them from taking targeted anti-EGFR therapies. Larger series are needed to confirm these results.

Signaling cross-talk in the resistance to HER family receptor targeted therapy

Epidermal growth factor receptor (EGFR) and human EGFR 2 (HER2) have an important role in the initiation and progression of various types of cancer. Inhibitors targeting these receptor tyrosine kinases are some of the most successful targeted anticancer drugs widely used for cancer treatment; however, cancer cells have mechanisms of intrinsic and acquired drug resistance that pose as major obstacles in drug efficacy. Extensive studies from both clinical and laboratory research have identified several molecular mechanisms underlying resistance. Among them is the role of signaling cross-talk between the EGFR/HER2 and other signaling pathways. In this review, we focus particularly on this signaling cross-talk at the receptor, mediator and effector levels, and further discuss alternative approaches to overcome resistance. In addition to well-recognized signaling cross-talk involved in the resistance, we also introduce the cross-talk between EGFR/HER2-mediated pathways and pathways triggered by other types of receptors, including those of the Notch, Wnt and TNFR/IKK/NF-κB pathways, and discuss the potential role of targeting this cross-talk to sensitize cells to EGFR/HER2 inhibitors.

Targeting developmental pathways in children with cancer: what price success?

Much of current cancer research is aimed at exploiting cancers' molecular addictions through targeted therapeutics, with notable successes documented in clinical trials. By their nature, these agents have different side-effect profiles than conventional chemotherapy drugs. Although few targeted agents have attained regulatory approval for use in children, paediatric oncologists are gaining experience with these drugs, which can have unique short-term and long-term effects in developing children that are unrecognised in adults. This Review summarises the rationale for targeted therapy, challenges in paediatric drug development, unique side-effect profiles of targeted agents, limited data from children treated with targeted agents, and implications of current knowledge and gaps therein. The demonstrated and potential effects of targeted therapies on normal tissue development and function are discussed. Future clinical trial design should include carefully considered assessment of the developmental effects of targeted therapy, and informed supportive-care recommendations.

[EGFR mutation status in Uighur lung adenocarcinoma patients]

BACKGROUND AND OBJECTIVE

Epidermal growth factor receptor (EGFR), a transmembrane protein, is a member of the tyrosine kinase family. Gefitinib, an EGFR tyrosine-kinase inhibitors, has shown a high response rate in the treatment of lung cancer in patients with EGFR mutation. However, significant differences in EGFR mutations exist among different ethnic groups. The aim of this study is to investigate the prevalence of EGFR mutations in Uighur lung adenocarcinoma patients by using a rapid and sensitive detection method and to analyze EGFR mutation differences compared with Han lung adenocarcinoma patients.

METHODS

We examined lung adenocarcinoma tissues from 138 patients, including 68 Uighur lung adenocarcinoma patients and 70 Han lung adenocarcinoma patients, for EGFR mutations in exons 18, 19, 20, and 21 by using the amplification refractory mutation system (ARMS) PCR method. The mutation differences between Uighur and Han lung adenocarcinoma were compared by using the chi-square test method.

RESULTS

EGFR mutations were detected in 43 (31.2%) of the 138 lung adenocarcinoma patients. EGFR mutations were detected in 11 (16.2%) of the 68 Uighur lung adenocarcinoma patients and in 32 (45.7%) of the 70 Han lung adenocarcinoma patients. Significant differences were observed in the EGFR mutations between Uighur lung adenocarcinoma patients and Han lung adenocarcinoma patients (P<0.001).

CONCLUSIONS

Our results indicate that the EGFR mutation in Uighur lung adenocarcinoma patients (16.2%) is significantly lower than that in Han lung adenocarcinoma patients (45.7%).

Discovery of new HER2/EGFR dual kinase inhibitors based on the anilinoquinazoline scaffold as potential anti-cancer agents

Herein, we designed and synthesized certain anilinoquinazoline derivatives bearing bulky arylpyridinyl, arylpropenoyl and arylpyrazolyl moieties at the 4' position of the anilinoquinazoline, as potential dual HER2/EGFR kinase inhibitors. A detailed molecular modeling study was performed by docking the synthesized compounds in the active site of the epidermal growth factor receptor (EGFR). The synthesized compounds were further tested for their inhibitory activity on EGFR and HER2 tyrosine kinases. The aryl 2-imino-1,2-dihydropyridine derivatives 5d and 5e displayed the most potent inhibitory activity on EGFR with IC50 equal to 2.09 and 1.94 μM, respectively, and with IC50 equal to 3.98 and 1.04 μM on HER2, respectively. Furthermore, the anti-proliferative activity of these most active compounds on MDA-MB-231 breast cancer cell lines, known to overexpress EGFR, showed an IC50 range of 2.4 and 2.5 μM, respectively.

Molecular mapping the presence of druggable targets in preinvasive and precursor breast lesions: a comprehensive review of biomarkers related to therapeutic interventions

The analysis of clinical breast samples using biomarkers is integral to current breast cancer management. Currently, a limited number of targeted therapies are standard of care in breast cancer treatment. However, these targeted therapies are only suitable for a subset of patients and resistance may occur. Strategies to prevent the occurrence of invasive lesions are required to reduce the morbidity and mortality associated with the development of cancer. In theory, application of targeted therapies to pre-invasive lesions will prevent their progression to invasive lesions with full malignant potential. The diagnostic challenge for pathologists is to make interpretative decisions on early detected pre-invasive lesions. Overall, only a small proportion of these pre-invasive lesions will progress to invasive carcinoma and morphological assessment is an imprecise and subjective means to differentiate histologically identical lesions with varying malignant potential. Therefore differential biomarker analysis in pre-invasive lesions may prevent overtreatment with surgery and provide a predictive indicator of response to therapy. There follows a review of established and emerging potential druggable targets in pre-invasive lesions and correlation with lesion morphology.

Expression and potential role of ErbB receptors in type II endometrial cancer

OBJECTIVE

Endometrial cancer is the most common malignancy of the female genital tract. Based on clinical and pathological features, endometrial cancer is classified into two types. The aim of our study was to describe the expression and the potential clinical role of ErbB receptors in Greek patients with type II endometrial cancer.

STUDY DESIGN

Between 1991 and 2008, 10 women with histologically confirmed type II endometrial cancer were referred to the Department of Gynecologic Oncology of the University of Patras Medical School. Tissue specimens from endometrial lesions were immunostained for EGFR, ErbB-2, ErbB-3 and ErbB-4.

RESULTS

For EGFR, 5 cases were positive (50%) and 5 cases were negative. For ErbB-2, 9 cases were positive (90%) and 1 case was negative. For ErbB-3, all cases were positive. For ErbB-4, 7 cases were positive (70%) and 3 cases were negative. Also for all ErbB receptors, 5 cases were positive (50%). During follow up, 3 patients died from their disease. All of them had papillary serous endometrial cancer and 2 of them were positive for all ErbB receptors.

CONCLUSION

Although our study was based on a small number of cases, it is obvious that we had high expression levels of ErbB receptors in patients with type II endometrial cancer. Also the majority of patients with dismal outcome were positive for all ErbB receptors. This is very important, as ErbB-targeted therapies may be clinically active as adjuvant therapy in well-defined subgroups of type II EC patients with EGFR and ErbB-2 overexpression.

Lapatinib inhibits meiotic maturation of porcine oocyte-cumulus complexes cultured in vitro in gonadotropin-supplemented medium

OBJECTIVE

To determine whether inhibition of epidermal growth factor (EGF) receptor tyrosine kinase with lapatinib affects oocyte maturation, expression of the cumulus expansion-associated genes such as tumor necrosis factor alpha-induced protein 6 (TNFAIP6) and prostaglandin-endoperoxide synthase 2 (PTGS2), and synthesis of hyaluronan (HA) and progesterone (P) by porcine oocyte cumulus complexes (OCC).

DESIGN

Our work focuses on lapatinib, an orally active small molecule that selectively inhibits the tyrosine kinase domain of both EGF receptor and human EGF receptor 2, and downstream signaling.

SETTING

A reproductive biology laboratory.

PATIENT(S)

Not applicable.

INTERVENTION(S)

Porcine OCC were cultured in vitro in a medium with FSH/LH in the presence/absence of lapatinib.

MAIN OUTCOME MEASURE(S)

Methods performed: real-time reverse transcriptase-polymerase chain reaction (PCR), immunofluorescence, RIA.

RESULT(S)

In FSH/LH-stimulated and expanded cumulus oophorus extracellular matrix, HA was detected with biotinylated HA-binding proteins. However, weaker HA- and weaker cytoplasmic TNFAIP6 were detected were detected in lapatinib-pretreated OCC. The expression of the two cumulus expansion-associated gene transcripts was significantly decreased and synthesis of HA by cumulus cells was reduced. Lapatinib (10 μM) inhibited FSH/LH-induced oocyte meiotic maturation. Progesterone production increased after OCC stimulation with FSH/LH and was significantly decreased by lapatinib (10 μM).

CONCLUSION(S)

Lapatinib inhibits oocyte maturation and reduces expression of cumulus expansion-associated transcripts, and synthesis of HA and P in OCC cultured in vitro in FSH/LH-supplemented medium.

Suppression of HER-2 via siRNA interference promotes apoptosis and decreases metastatic potential of SKOV‑3 human ovarian carcinoma cells

The aberrant expression of human epidermal growth factor receptor-2 (HER-2) has been detected in ovarian cancer. However, the role of HER-2 in the development of ovarian cancer has not been sufficiently elucidated. The objective of this study was to determine the role of HER-2 in the apoptosis and metastasis of SKOV-3 ovarian cancer cells. SKOV-3 cells were transfected with three double‑stranded small interfering RNA (siRNA) molecules that target HER-2. Various sequences were synthesized by T7 transcription in vitro to select the most effective HER-2‑silencing siRNA. SKOV-3 cells were examined for growth inhibition using the MTT proliferation assay and apoptosis was assessed using flow cytometry and TUNEL assay. The Matrigel basement memebrane matrix was used to assess invasion and chemotactic mobility, as a model of tumor cell metastasis. Western blot analysis was used to detect the expression of matrix metallopeptidase-9 (MMP-9), E-cadherin, N-cadherin and vimentin. siRNA interference in HER-2 resulted in decreased cell proliferation and invasion and increased apoptosis. Western blot analysis demonstrated a marked increase in E-cadherin and MMP-9 and a reduction in N-cadherin and vimentin protein levels in the SKOV-3 cells. The suppression of HER-2 expression resulted in apoptosis and the inhibition of metastasis of SKOV-3 cells. Therefore, the overexpression of the HER-2 gene can enhance the metastatic potential of SKOV-3 cells by increasing the protein levels of MMP-9. Epithelial-mesenchymal transition may be involved in the HER-2 siRNA-induced invasion and migration of SKOV-3 cells. Taken together, these results suggest that HER-2 functions as an oncogene and may thus be an attractive therapeutic target in SKOV-3 ovarian cancer cells.

What is recent in pancreatic cancer immunotherapy?

Pancreatic cancer (PC) represents an unresolved therapeutic challenge, due to the poor prognosis and the reduced response to currently available treatments. Pancreatic cancer is the most lethal type of digestive cancers, with a median survival of 4-6 months. Only a small proportion of PC patients is curative by surgical resection, whilst standard chemotherapy for patients in advanced disease generates only modest effects with considerable toxic damages. Thus, new therapeutic approaches, specially specific treatments such as immunotherapy, are needed. In this paper we analyze recent preclinical and clinical efforts towards immunotherapy of pancreatic cancer, including passive and active immunotherapy approaches, designed to target pancreatic-cancer-associated antigens and to elicit an antitumor response in vivo.

Continued treatment with gefitinib beyond progressive disease benefits patients with activating EGFR mutations

BACKGROUND

Gefitinib is an effective treatment for patients with non-small cell lung cancer who harbor activating epidermal growth factor receptor (EGFR) mutations. However, no optimal strategy has been established for these patients after gefitinib fails. The aim of this retrospective study was to assess the survival benefit of continued gefitinib treatment in these cases.

PATIENTS AND METHODS

We analyzed gefitinib responders with activating EGFR mutations who developed progressive disease (PD) during the course of therapy. Prognostic variables were analyzed using a Cox proportional-hazards model.

RESULTS

A total of 134 patients were retrospectively reviewed. Exon-19 deletion mutations and L858R point mutations were detected in 71 and 63 patients, respectively. Median survival time after PD with gefitinib was 14.3 months (95% confidence interval: 11.7-16.9). The median duration of continued gefitinib therapy beyond PD was 3.2 months. Statistical analysis showed that good performance status (0-1) (hazard ratio [HR]: 0.6), progression of a previously evaluated lesion (HR: 0.6), and at least 3 months of continued treatment (HR: 0.4) were independent prognostic factors.

CONCLUSION

Continuation of gefitinib beyond PD is an effective optional treatment in EGFR-mutated patients.

Role of epidermal growth factor receptor in breast cancer

Decades of research in molecular oncology have brought about promising new therapies which are designed to target specific molecules which promote tumor growth and survival. The epidermal growth factor receptor (EGFR) is one of the first identified important targets of these novel antitumor agents. Approximately half of cases of triple-negative breast cancer (TNBC) and inflammatory breast cancer (IBC) overexpress EGFR. Thus, EGFR inhibitors for treatment of breast cancer have been evaluated in several studies. However, results so far have been disappointing. One of the reasons for these unexpected results is the lack of biomarkers for predicting which patients are most likely to respond to EGFR inhibitors. Recent studies have shown that EGFR and its downstream pathway regulate epithelial-mesenchymal transition, migration, and tumor invasion and that high EGFR expression is an independent predictor of poor prognosis in IBC. Further, recent studies have shown that targeting EGFR enhances the chemosensitivity of TNBC cells by rewiring apoptotic signaling networks in TNBC. These studies indicate that EGFR-targeted therapy might have a promising role in TNBC and IBC. Further studies of the role of EGFR in TNBC and IBC are needed to better understand the best way to use EGFR-targeted therapy-e.g., as a chemosensitizer or to prevent metastases-to treat these aggressive diseases.

Prognostic value of circulating cytokines for stage III colon cancer

BACKGROUND

This study was to determine preoperative serum levels of epidermal growth factor (EGF), interleukin-6 (IL-6), and C-reactive protein (CRP) in stage III colon cancer and correlate them with disease status and prognosis. The circulating EGF in correlation with primary site epidermal growth factor receptor (EGFR) was also evaluated.

METHODS

Seventy-seven patients with curatively resected stage III colon cancer were selected for analysis. Enzyme-linked immunosorbent assay was used to determine EGF and IL-6 serum levels, and serum CRP levels were measured via immunoturbidimetry. EGFR expression was observed with immunohistochemical studies.

RESULTS

The median levels of EGFR, IL-6, and CRP were 189.4 pg/mL, 9.09 pg/mL, and 1.4 mg/mL, respectively. The factors related to recurrence with statistical significance included positive node status (P = 0.041), lymphovascular invasion (P = 0.001), and preoperative IL-6 level ≥9 pg/mL (P = 0.020). CRP and EGF levels were not significantly associated with disease-free survival rates (P = 0.438 and P = 0.309, respectively). Multivariate analysis using Cox's proportion model revealed that lymph node status was the single independent prognostic factor for predicting time until recurrence (odds ratio, 4.99; 95% confidence interval, 1.09-22.91; P = 0.038).

CONCLUSION

IL-6 expression in stage III colon cancer patients appears to be a prognostic marker of tumor behavior. No correlations between serum EGF concentrations and tumor EGFR positivity were found in this study.

A role for the epidermal growth factor receptor signaling in development of intestinal serrated polyps in mice and humans

BACKGROUND & AIMS

Epithelial cancers can be initiated by activating mutations in components of the mitogen-activated protein kinase signaling pathway such as v-raf murine sarcoma viral oncogene homolog B1 (BRAF), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), or epidermal growth factor receptor (EGFR). Human intestinal serrated polyps are a heterogeneous group of benign lesions, but some progress to colorectal cancer. Tumors that arise from these polyps frequently contain activating mutations in BRAF or KRAS, but little is known about the role of EGFR activation in their development.

METHODS

Polyp samples were obtained from adults during screening colonoscopies at Mount Sinai Hospital in New York. We measured levels of EGFR protein and phosphorylation in human serrated polyps by immunohistochemical and immunoblot analyses. We generated transgenic mice that express the ligand for EGFR, Heparin-binding EGF-like growth factor (HB-EGF), in the intestine.

RESULTS

EGFR and the extracellular-regulated kinases (ERK)1/2 were phosphorylated in serrated areas of human hyperplastic polyps (HPPs), sessile serrated adenomas, and traditional serrated adenomas. EGFR and ERK1/2 were phosphorylated in the absence of KRAS or BRAF activating mutations in a subset of HPP. Transgenic expression of the EGFR ligand HB-EGF in the intestines of mice promoted development of small cecal serrated polyps. Mice that expressed a combination of HB-EGF and US28 (a constitutively active, G-protein-coupled receptor that increases processing of HB-EGF from the membrane) rapidly developed large cecal serrated polyps. These polyps were similar to HPPs and had increased phosphorylation of EGFR and ERK1/2 within the serrated epithelium. Administration of pharmacologic inhibitors of EGFR or MAPK to these transgenic mice significantly reduced polyp development.

CONCLUSIONS

Activation of EGFR signaling in the intestine of mice promotes development of serrated polyps. EGFR signaling also is activated in human HPPs, sessile serrated adenomas, and traditional serrated adenomas.

Feasibility of eradication of breast cancer cells remaining in postlumpectomy cavity and draining lymph nodes following intracavitary injection of radioactive immunoliposomes

Most diagnosed early stage breast cancer cases are treated by lumpectomy and adjuvant radiation therapy, which significantly decreases the locoregional recurrence but causes inevitable toxicity to normal tissue. By using a technique of preparing liposomes carrying technetium-99m ((99m)Tc), rhenium-186 ((186)Re), or rhenium-188 ((188)Re) radionuclides, as well as chemotherapeutic agents, or their combination, for cancer therapy with real time image-monitoring of pharmacokinetics and prediction of therapy effect, this study investigated the potential of a novel targeted focal radiotherapy with low systemic toxicity using radioactive immunoliposomes to treat both the surgical cavity and draining lymph nodes in a rat breast cancer xenograft positive surgical margin model. Immunoliposomes modified with either panitumumab (anti-EGFR) or bevacizumab (anti-VEGF) were remote loaded with (99m)Tc diagnostic radionuclide, and injected into the surgical cavity of female nude rats with positive margins postlumpectomy. Locoregional retention and systemic distribution of (99m)Tc-immunoliposomes were investigated by nuclear imaging, stereofluorescent microscopic imaging, and gamma counting. Histopathological examination of excised draining lymph nodes was performed. The locoregional retention of (99m)Tc-immunoliposomes in each animal was influenced by the physiological characteristics of the surgical site of individual animals. Panitumumab- and bevacizumab-liposome groups had higher intracavitary retention compared with the control liposome groups. Draining lymph node uptake was influenced by both the intracavitary radioactivity retention level and metastasis status. The panitumumab-liposome group had higher accumulation on the residual tumor surface and in the metastatic lymph nodes. Radioactive liposomes that were cleared from the cavity were metabolized quickly and accumulated at low levels in vital organs. Therapeutic radionuclide-carrying specifically targeted panitumumab- and bevacizumab-liposomes have increased potential compared to non-antibody targeted liposomes for postlumpectomy focal therapy to eradicate remaining breast cancer cells inside the cavity and draining lymph nodes with low systemic toxicity.

Development and validation of a spectrofluorimetric method for the determination of erlotinib in spiked human plasma

A rapid and sensitive spectrofluorimetric method was developed and validated for the determination of erlotinib (ETB), a potent anticancer drug, in spiked human plasma without any derivatization. The described method was validated and the analytical parameters of linearity, accuracy, precision (intra- and inter-day), limit of detection (LOD), and limit of quantification (LOQ) were evaluated. The relation between the fluorescence intensity and concentration was found to be linear (r(2) 0.9998) over the range 125 to 1000 ng/mL with the detection limit of 15 ng/mL. A simple liquid-liquid extraction method was followed in order to extract the drug from spiked plasma. The mean absolute recoveries of ETB were 85.59 % (±0.57), 86.91 % (±1.77) and 89.31 % (±3.01) at spiked plasma ETB concentration of 5000, 3750 and 2500 ng/mL, respectively. The spectrofluorimetric method presented here is a rapid, simple, specific, and reproducible method and can be used to characterize the plasma pharmacokinetics of ETB.

Control of FLIP(L) expression and TRAIL resistance by the extracellular signal-regulated kinase1/2 pathway in breast epithelial cells

Increased activation of the epidermal growth factor receptor (EGFR) is frequently observed in tumors, and inhibition of the signaling pathways originated in the EGFR normally renders tumor cells more sensitive to apoptotic stimuli. However, we show that inhibition of EGFR signaling in non-transformed breast epithelial cells by EGF deprivation or gefitinib, an inhibitor of EGFR tyrosine kinase, causes the upregulation of the long isoform of caspase-8 inhibitor FLICE-inhibitory protein (FLIP(L)) and makes these cells more resistant to the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We demonstrate that the extracellular signal-regulated kinase (ERK)1/2 pathway plays a pivotal role in the regulation of FLIP(L) levels and sensitivity to TRAIL-induced apoptosis by EGF. Upregulation of FLIP(L) upon EGF deprivation correlates with a decrease in c-Myc levels and c-Myc knockdown by siRNA induces FLIP(L) expression. FLIP(L) upregulation and resistance to TRAIL in EGF-deprived cells are reversed following activation of an estrogen activatable form of c-Myc (c-Myc-ER). Finally, constitutive activation of the ERK1/2 pathway in HER2/ERBB2-transformed cells prevents EGF deprivation-induced FLIP(L) upregulation and TRAIL resistance. Collectively, our results suggest that a regulated ERK1/2 pathway is crucial to control FLIP(L) levels and sensitivity to TRAIL in non-transformed cells, and this mechanism may explain the increased sensitivity of tumor cells to TRAIL, in which the ERK1/2 pathway is frequently deregulated.

Epidermal growth factor receptor (EGFR) in salivary gland carcinomas: potentials as therapeutic target

AIMS

Epidermal growth factor (EGFR) is involved in angiogenesis, cell differentiation, proliferation and progression of many cancers and is an important therapy target in lung and colorectal cancer. To determine the potential applicability of EGFR targeted therapies, EGFR status of over 800 salivary gland tumors of different entities were analyzed on DNA and protein level by FISH and IHC.

MATERIALS AND METHODS

A tissue microarray was constructed from 721 carcinomas and 205 adenomas of the salivary gland. EGFR expression and EGFR gene copy number was assessed by means of immunohistochemistry and fluorescence in situ hybridization (FISH). EGFR mutation analysis of exon 19 and 21 was performed in a subset of 107 carcinomas.

RESULTS

Positive immunohistochemical staining (definition?) for EGFR was shown in 324 of 663 (48.9%) salivary gland carcinomas. The frequency was dependent on the tumor entity and ranged from 17.9% (30 of 168 cases) positive immunostaining in acinic cell adenocarcinomas to 85.7% (42 of 49 cases) in Warthin tumors. No EGFR amplification was found by FISH. EGFR mutation analysis of Exon 19 and 21 in 107 salivary gland carcinomas revealed mutations in two acinic cell adenocarcinomas.

CONCLUSION

EGFR protein expression is common in salivary gland tumors but is not associated with gene amplification. Activating mutations of EGFR are rare. Nonetheless, selected cases of patients with salivary gland carcinomas might potentially benefit of anti-EGFR therapy.