Epidermal Growth Factor Receptor-targeted Therapy Research Articles

Lung Injury and Lung Cancer Caused by Cigarette Smoke-Induced Oxidative Stress: Molecular Mechanisms and Therapeutic Opportunities Involving the Ceramide-Generating Machinery and Epidermal Growth Factor Receptor

Chronic obstructive pulmonary disease (COPD) and lung cancer are frequently caused by tobacco smoking. However, these diseases present opposite phenotypes involving redox signaling at the cellular level. While COPD is characterized by excessive airway epithelial cell death and lung injury, lung cancer is caused by uncontrolled epithelial cell proliferation. Notably, epidemiological studies have demonstrated that lung cancer incidence is significantly higher in patients who have preexisting emphysema/lung injury. However, the molecular link and common cell signaling events underlying lung injury diseases and lung cancer are poorly understood. This review focuses on studies of molecular mechanism(s) underlying smoking-related lung injury (COPD) and lung cancer. Specifically, the role of the ceramide-generating machinery during cigarette smoke-induced oxidative stress leading to both apoptosis and proliferation of lung epithelial cells is emphasized. Over recent years, it has been established that ceramide is a sphingolipid playing a major role in lung epithelia structure/function leading to lung injury in chronic pulmonary diseases. However, new and unexpected findings draw attention to its potential role in lung development, cell proliferation, and tumorigenesis. To address this dichotomy in detail, evidence is presented regarding several protein targets, including Src, p38 mitogen-activated protein kinase, and neutral sphingomyelinase 2, the major sphingomyelinase that controls ceramide generation during oxidative stress. Furthermore, their roles are presented not only in apoptosis and lung injury but also in enhancing cell proliferation, lung cancer development, and resistance to epidermal growth factor receptor-targeted therapy for treating lung cancer.

Mutation analysis of genes in the EGFR pathway in Head and Neck cancer patients: implications for anti-EGFR treatment response.

BackgroundTargeted therapy against the Epidermal Growth Factor Receptor (EGFR) is among the most promising molecular therapeutics for Head and Neck Squamous Cell Carcinoma (HNSCC). However, drug resistance limits the clinical efficacy of anti-EGFR monoclonal antibodies and no predictive biomarker has entered the clinic yet.MethodsA retrospective clinical study was performed utilizing pathological specimens from 52 newly diagnosed HNSCC patients. These patients were screened for mutations in EGFR and KRAS. Tyrosine kinase mutations in EGFR and KRAS mutations were evaluated by high resolution melting analysis (HRMA), whereas EGFRvIII was determined using one-step real-time PCR. Finally, patient samples were screened for HPV-DNA by GP5+/6+ PCR. Survival analysis was performed using Kaplan-Meier analysis and significance was calculated using log-rank statistic.ResultsIn our study population no EGFRvIII mutations were present. However, two silent mutations were found; T785T in exon 20 and R836R in exon 21 of the EGFR gene. Additionally, HRMA revealed an abnormal KRAS melting pattern in 7.0% of the samples. However, the KRAS StripAssay could confirm only one sample with a G12S mutation and none of these samples could be confirmed by direct sequencing. HPV DNA was present in 3/25 larynx and 9/27 oropharynx tumors.ConclusionThe low rate of EGFR and KRAS mutations in this Belgian HNSCC population suggests that these genes will probably not play a major role in predicting response to anti-EGFR therapy in HNSCC. Hence, other predictive markers need to be discovered in order to optimize EGFR targeting therapy.

Comparison of KRAS mutation analysis of primary tumors and matched circulating cell-free DNA in plasmas of patients with colorectal cancer

Colorectal cancer (CRC) patients with KRAS mutations do not benefit from epidermal growth factor receptor (EGFR) targeted therapy. In clinical practice, identifying patients with KRAS mutations is critical prior to EGFR targeting therapy, and gene testing is generally performed using the DNA extracted from tumor tissue. The aim of this study was to compare the presence of KRAS mutations in circulating cell-free DNA (cfDNA) and primary tumor tissue using a peptide nucleic acid mediated polymerase chain reaction. We extracted and analyzed the DNA from plasmas and corresponding primary tumor samples from 52 patients with CRC. The results demonstrated that the detection rate of KRAS sequence variations was 50% (26 of 52) in plasma samples and 28.8% (15 of 52) in resected primary tumor tissue samples. The majority of KRAS mutations detected in tumors were also found in matched plasma specimens with an agreement rate of 78.8%. Eleven plasma cfDNA were found positive for KRAS mutation but not in their corresponding tissue. In conclusion, our results suggest that circulating cfDNA provides a better representation of the malignant disease as a whole and could be a reliable source of diagnostic DNA to replace the tumor tissue in a diagnostic setting.

Performance Evaluation Comparison of 3 Commercially Available PCR-based KRAS Mutation Testing Platforms

The identification of KRAS mutations in patients with certain types of cancer, including colonic adenocarcinoma and non-small cell lung carcinoma, has become increasingly important as these patients are contraindicated from receiving epidermal growth factor receptor-targeted therapies. Several polymerase chain reaction (PCR)-based tests are commercially available for KRAS mutation testing including Applied Biosystems KRAS Mutation Analysis on the ABI3130xl, Qiagen therascreen KRAS RGQ PCR on the Rotor-Gene Q MDx, and Qiagen KRAS Pyro on the PyroMark Q24; however, these tests have not been compared side by side. The purpose of this study was to evaluate the performance characteristics and workflow for 3 PCR-based methods of detecting KRAS mutation status. We evaluated the performance characteristics and workflow for 3 commercially available KRAS mutation detection platforms. All of the 188 samples run were successful, with 29% being positive for the KRAS mutation. Of the positive tests, Applied Biosystems detected 84% of the positive cases, whereas Qiagen therascreen RGQ and Qiagen KRAS Pyro detected 100% of the positive cases. In cases of discrepancy between Applied Biosystems and therascreen RGQ, Pyro agreed with therascreen RGQ 95% of the time. Qiagen therascreen RGQ and Pyro were comparable in terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy, with all values being 100%. All 3 techniques accurately identified the appropriate mutation in the known control specimens. In summary, all 3 tests are relatively comparable for detecting the KRAS mutation, with Applied Biosystems having a slightly lower sensitivity, negative predictive value, and accuracy than therascreen RGQ and Pyro.

Recent applications of chemosensitivity tests for colorectal cancer treatment.

The evaluation of therapeutic efficacy is necessary to predict the outcome of patients with metastatic colorectal cancer (CRC). In these patients, there is a critical need for predictive chemosensitivity assays and biomarkers to optimize efficacy and minimize toxicity. The introduction of targeted agents has improved the progression-free survival and overall survival of patients with metastatic disease. However, approximately 50% of patients do not show a positive response to chemotherapy and the selection of patients likely to respond to a specific regimen remains challenging. Cell culture-based chemosensitivity tests use autologous viable tumor cells to evaluate susceptibility to specific agents in vitro and predict their direct effects. Adenosine triphosphate-based assays and methyl thiazolyl-diphenyl-tetrazolium bromide-based assays are used widely as sensitivity tests because of their short assay period, technical simplicity, and the requirement of small amount of specimen. Among protein- and gene-based chemosensitivity assays, assessment of KRAS mutation status predicts the response to epidermal growth factor receptor-targeted therapy in CRC patients. The validation of predictive and prognostic markers enables the selection of therapeutic regimens with optimal efficacy and minimal toxicity for each patient, which has been termed personalized treatment. This review summarizes currently available predictive and prognostic chemosensitivity tests for metastatic CRC.

DNA Testing and Molecular Screening for Colon Cancer

Colon cancer develops and progresses as a consequence of abnormal cellular molecular changes, many of which result in mutant DNA. Modern molecular techniques allow examination of individual patient genetic data that ascribe risk, predict outcome, and/or modify an approach to therapy. DNA testing and molecular screening are in use today and are becoming a critical and necessary part of routine patient care. Assessing at-risk patients for hereditary colon cancer is predicted to move from individual gene testing that is commonly performed today to whole exome or whole genome sequencing, providing additional vast information of the patient's genome that might not be related to the colon cancer syndrome. Detecting mutant DNA from shed tumor cells in fecal material for colon cancer screening will increase in diagnostic accuracy over time, with improvements in the panel of mutant DNA being examined and through clinical testing. DNA mutations and other molecular changes detected directly from within the colon cancer help to inform and guide the physician for the best approach for optimal patient care and outcome. The use of epidermal growth factor receptor-targeted therapy in advanced colon cancer patients requires knowledge of the mutation status for KRAS and BRAF genes, and knowing the mutational status of PIK3CA may predict how patients respond to aspirin to prevent colon cancer recurrence. Biologically driven decision-making, or precision medicine, is becoming increasingly adopted for optimal care and outcome for colon cancer patients. Gastroenterologists will need to be increasingly aware.

Preparation of clinical-grade (89) Zr-panitumumab as a positron emission tomography biomarker for evaluating epidermal growth factor receptor-targeted therapy.

Panitumumab is a fully human monoclonal antibody approved for the treatment of epidermal growth factor receptor (EGFR) positive colorectal cancer. Recently, panitumumab has been radiolabeled with (89) Zr and evaluated for its potential to be used as immuno-positron emission tomography (PET) probe for EGFR positive cancers. Interesting preclinical results published by several groups of researchers have prompted us to develop a robust procedure for producing clinical-grade (89) Zr-panitumumab as an immuno-PET probe to evaluate EGFR-targeted therapy. In this process, clinical-grade panitumumab is bio-conjugated with desferrioxamine chelate and subsequently radiolabeled with (89) Zr resulting in high radiochemical yield (>70%, n = 3) and purity (>98%, n = 3). All quality control (QC) tests were performed according to United States Pharmacopeia specifications. QC tests showed that (89) Zr-panitumumab met all specifications for human injection. Herein, we describe a step-by-step method for the facile synthesis and QC tests of (89) Zr-panitumumab for medical use. The entire process of bioconjugation, radiolabeling, and all QC tests will take about 5 h. Because the synthesis is fully manual, two rapid, in-process QC tests have been introduced to make the procedure robust and error free.

Epidermal Growth Factor Receptor-targeted Therapy in Squamous Cell Carcinoma of the Penis: A Report of 3 Cases

To describe 3 cases of advanced refractory penile cancer treated with targeted therapy against the epidermal growth factor receptor (EGFR). We identified 3 patients with advanced penile cancer who had disease progression after platinum chemotherapy refractory and who subsequently received EGFR-targeted therapy. Their tumor tissue was evaluated for expression of EGFR by immunohistochemistry and messenger ribonucleic acid quantitation and was also tested for the presence of human papillomavirus deoxyribonucleic acid by line hybridization. K-ras mutation was evaluated by polymerase chain reaction for 6 mutations in codon 12 and 1 mutation in codon13. One patient responded to cetuximab and remains disease-free 42 months after presentation. One patient responded to panitumumab, then suffered relapse. One other progressed through EGFR-targeted therapy. EGFR expression by immunohistochemistry was 1-2+ in all cases, and messenger ribonucleic acid expression ranged from 4.08 to 7.33. No K-ras mutations or human papillomavirus deoxyribonucleic acid was detected. We report 3 cases in which EGFR-targeted therapy was used to treat platinum-refractory penile cancer patients. Because 2 of the 3 had clinical benefit, future prospective trials of EGFR-targeted therapy in penile cancer are warranted.

Editorial Comment

Epidermal growth factor receptor (EGFR) is expressed in nonsmall cell lung cancer, head and neck squamous cell carcinoma, colorectal cancer, and breast cancer. In each of these diseases, there are EGFR inhibitors that are approved for these conditions. EGFR is expressed in squamous cell penile cancer.1Barnholtz-Sloan J.S. Maldonado J.L. Pow-sang J. Giuliano A.R. Incidence trends in primary malignant penile cancer.Urol Oncol. 2007; 25: 361-367Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar, 2Bahl A.K. Sohail M. Johnson D. et al.EGFR overexpression in invasive squamous cell carcinoma of the penis.J Clin Onc. 2010; 28 (ASCO proceedings): e15078Google Scholar, 3Gou H.-F. Li X. Qiu M. et al.Epidermal growth factor receptor (EGFR)-RAS signaling pathway in penile squamous cell carcinoma.PLoS ONE. 2013; 8: e62175Crossref PubMed Scopus (39) Google Scholar The question: is it potentially useful in patients with squamous cell penile cancer? There are important parameters whether a target for treatment is important or not. Is the target over expressed, could it be inhibited, is it the predominant target, is it an important factor for growth for this cancer, and could it be given safely. There are more questions than answers. Gou et al3Gou H.-F. Li X. Qiu M. et al.Epidermal growth factor receptor (EGFR)-RAS signaling pathway in penile squamous cell carcinoma.PLoS ONE. 2013; 8: e62175Crossref PubMed Scopus (39) Google Scholar in a study of 150 patients in China with penile cancer showed EGFR expression was positive in all the 150 cases. Five cases (3.3%) were 1+, 7 (4.7%) were 2+, 21 (14%) were 3+, and 117 (78%) were 4+. The rate of EGFR over expression was 92%. No significant correlation was observed between the EGFR expression and tumor grade (P = .215), pT stage (P = .053), or lymph node metastases (P = .685). In a study by Lavens et al4Lavens N. Gupta R. Wood L.A. EGFR overexpression in squamous cell carcinoma of the penis.Curr Oncol. 2010 February; 17: 4-6PubMed Google Scholar from a selected 8-year time period, 17 cases were obtained and studied. The median age of all patients was 66 years (range, 46-95). All 17 cases over expressed EGFR. Expression was 3+ in 14 cases and 2+ in 3 cases. The case series highlights the importance of reviewing the biology of the disease and the importance of identifying markers that are expressed. Two of the 3 patients responded to the treatment, and 1 had a response lasting 42 months. Several investigators have shown that patients with EGFR expression in small case series also did respond to EGFR inhibitors. On the basis of these preliminary data, I agree with the authors that a clinical trial should be done. In addition, it is important to develop less toxic oral therapy for penile cancer because chemotherapy can be toxic especially for patient with advanced cancer, and additionally there are no options after tumor progression on cisplatin-based treatment. To test the question whether EGFR inhibitors are effective in the treatment of this cancer, there is an ongoing trial of Dacomitinib (PF-00299804 pan HER inhibitor/EGFR) in advanced/metastatic squamous cell carcinoma of the penis with the primary endpoint of response rate. NCT01728233 was based on early results from Tumori Milan and the University of Texas MD Anderson.5Clinical Trials.gov 2013 NCT identifier number 01728233.Google Scholar This might be the next step big for this cancer. Epidermal Growth Factor Receptor-targeted Therapy in Squamous Cell Carcinoma of the Penis: A Report of 3 CasesUrologyVol. 83Issue 1PreviewTo describe 3 cases of advanced refractory penile cancer treated with targeted therapy against the epidermal growth factor receptor (EGFR). Full-Text PDF ReplyUrologyVol. 83Issue 1PreviewAs the editorial comment points out, the gap between our knowledge of which markers are expressed on tumor cells and which of these markers will provide a successful therapeutic target has become increasingly apparent. Furthermore, the complexities of signaling pathways have complicated attempts to target receptors identified on tumor tissue: for example, K-ras mutations affect response to epidermal growth factor receptor (EGFR)–targeted therapy. In penile cancer, with nearly ubiquitous EGFR expression and low incidence of K-ras mutation, we might expect some response to EGFR-targeted therapy but will need to interrogate the pathway more comprehensively to understand why some patients benefit and others do not. Full-Text PDF

Poor-prognosis colon cancer is defined by a molecularly distinct subtype and develops from serrated precursor lesions

Colon cancer is a clinically diverse disease. This heterogeneity makes it difficult to determine which patients will benefit most from adjuvant therapy and impedes the development of new targeted agents. More insight into the biological diversity of colon cancers, especially in relation to clinical features, is therefore needed. We demonstrate, using an unsupervised classification strategy involving over 1,100 individuals with colon cancer, that three main molecularly distinct subtypes can be recognized. Two subtypes have been previously identified and are well characterized (chromosomal-instable and microsatellite-instable cancers). The third subtype is largely microsatellite stable and contains relatively more CpG island methylator phenotype-positive carcinomas but cannot be identified on the basis of characteristic mutations. We provide evidence that this subtype relates to sessile-serrated adenomas, which show highly similar gene expression profiles, including upregulation of genes involved in matrix remodeling and epithelial-mesenchymal transition. The identification of this subtype is crucial, as it has a very unfavorable prognosis and, moreover, is refractory to epidermal growth factor receptor-targeted therapy.

Sustained EKR inhibition by EGFR targeting therapies is a predictive factor for synergistic cytotoxicity with PDT as neoadjuvant therapy

BackgroundTyrosin kinase inhibitors (TKIs) and monoclonal antibodies aimed to target epidermal growth factor receptor (EGFR) have shown limited effect as monotherapies and drug resistance is a major limitation for therapeutic success. Adjuvant therapies to EGFR targeting therapeutics are therefore of high clinical relevance. MethodsThree EGFR targeting drugs, Cetuximab, Erlotinib and Tyrphostin AG1478 were used in combination with photodynamic therapy (PDT) in two EGFR positive cell lines, A-431 epidermoid skin carcinoma and WiDr colorectal adenocarcinoma cells. The amphiphilic meso-tetraphenylporphine with 2 sulphonate groups on adjacent phenyl rings (TPPS2a) was utilized as a photosensitizer for PDT. The cytotoxic outcome of the combined treatments was evaluated by cell counting and MTT. Cellular signalling was explored by Western blotting. ResultsPDT as neoadjuvant to Tyrphostin in A-431 cells as well as to Tyrphostin or Erlotinib in WiDr cells revealed synergistic cytotoxicity. In contrast, Erlotinib or Cetuximab combined with neoadjuvant PDT induced an antagonistic effect on cell survival of A-431 cells. Neoadjuvant PDT and EGFR targeting therapies induced a synergistic inhibition of ERK as well as synergistic cytotoxicity only when the EGFR targeting monotherapies caused a prolonged ERK inhibition. There were no correlation between EGFR inhibition by the EGFR targeting monotherapies or the combined therapies and the cytotoxic outcome combination-therapies. ConclusionsThe results suggest that sustained ERK inhibition by EGFR targeting monotherapies is a predictive factor for synergistic cytotoxicity when combined with neoadjuvant PDT. General significanceThe present study provides a rationale for selecting anticancer drugs which may benefit from PDT as adjuvant therapy.

EGFR Expression and Gene Copy Number in Malignant Pleural Mesothelioma in Turkey

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis. Standart chemotherapy regimens still remain palliative. There is urgent need for novel therapy options such as targeted therapies in order to improve the outcome of the patients. Epidermal growth factor receptor (EGFR) is a common target for cancer chemotherapy. There is relatively less data in the literature regarding EGFR expression status in MPMs. In this study we analysed EGFR expression immunohistochemically in 21 Turkish MPM cases. As gene amplificaiton is one of the mechanism responsible from receptor overexpression, we also studied EGFR gene copy number by fluorescent in situ hybridization (FISH) method. We found EGFR overexpression in 16/19 (84.2%) cases. EGFR overexpression was seen in all epithelial and most (66,6%) biphasic tumor types. There was, however, no association between EGFR expression and survival. Although we did not find gene amplification, we detected gene copy number increase (e.g., high polysomy) in two cases (9,5%). Gene copy number increase seems to be responsible from EGFR overexpression in only a small percentage of MPM cases. Further studies investigating other potential factors which might be associated with EGFR expression are needed, and more clinical trials are required to evaluate whether MPM patients are candidates for EGFR targeting therapies.

Metastatic Mucinous Ovarian Cancer and Treatment Decisions Based on Histology and Molecular Markers Rather Than the Primary Location

Approximately 22,000 cases of ovarian cancer occur each year in the United States, and likely fewer than 2000 cases of mucinous ovarian cancers. Although 90% of patients with mucinous ovarian cancer present with stage I disease and have curative surgeries, advanced-stage disease is known to have a poor response to standard platinum- and taxane-based chemotherapy. Despite limited enthusiasm, standard chemotherapy is still recommended for most patients with advanced-stage mucinous malignancies of the ovary. This report presents an unusual case of a woman with HER2-positive metastatic mucinous carcinoma of the ovary treated with chemotherapy regimens typically used for colorectal malignancies, followed by epidermal growth factor receptor-targeted therapies.

A phase II trial to assess efficacy and safety of afatinib in extensively pretreated patients with HER2-negative metastatic breast cancer

Afatinib (BIBW 2992) is an ErbB-family blocker that irreversibly inhibits signaling from all relevant ErbB-family dimers. Afatinib has demonstrated preclinical activity in human epidermal growth factor receptor HER2 (ErbB2)-positive and triple-negative xenograft models of breast cancer, and clinical activity in phase I studies. This was a multicenter phase II study enrolling patients with HER2-negative metastatic breast cancer progressing following no more than three lines of chemotherapy. No prior epidermal growth factor receptor-targeted therapy was allowed. Patients received 50-mg afatinib once daily until disease progression. Tumor assessment was performed at every other 28-day treatment course. The primary endpoint was clinical benefit (CB) for ≥4 treatment courses in triple-negative (Cohort A) metastatic breast cancer (TNBC) and objective responses measured by Response Evaluation Criteria in Solid Tumors in patients with HER2-negative, estrogen receptor-positive, and/or progesterone receptor-positive breast cancer (Cohort B). Fifty patients received treatment, including 29 patients in Cohort A and 21 patients in Cohort B. No objective responses were observed in either cohort. Median progression-free survival was 7.4 and 7.7 weeks in Cohorts A and B, respectively. Three patients with TNBC had stable disease for ≥4 treatment courses, one of them for 12 courses (median 26.3 weeks; range 18.9–47.9 weeks). The most frequently observed afatinib-associated adverse events (AEs) were gastrointestinal and skin-related side effects, which were manageable by symptomatic treatment and dose reductions. Afatinib pharmacokinetics were comparable to those observed in previously reported phase I trials. In conclusion, afatinib had limited activity in HER2-negative breast cancer. AEs were generally manageable and mainly affected the skin and the gastrointestinal tract.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-012-2126-1) contains supplementary material, which is available to authorized users.

Abstract 7: Knockdown of EGFR to investigate its therapeutic potential for treatment of non-small cell lung cancers

Abstract Background: Epidermal growth factor receptor (EGFR) is a transmembrane protein consisting of an extracellular ligand-binding domain, and its activation leads to a multitude of effects including cell proliferation, cell differentiation, angiogenesis, metastasis, and antiapoptosis. EGFR can be a partner of heterodimer of other EGFR family such as HER2 and HER3. EGFR is often overexpressed in non-small cell lung cancer (NSCLC). Anti-EGFR agents including EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have considered to be effective for NSCLC when drug sensitive EGFR mutation is present. However, inherent and acquired resistances are major problems of EGFR targeting therapies. In this study, we knock-downed EGFR using small interfering RNAs (siRNAs) in NSCLC cell lines to examine the significance of targeting EGFR for NSCLC therapy. Materials and methods: We treated 14 NSCLC cell lines including nine EGFR mutant and five EGFR wild-type cell lines by geftinib or siRNAs for EGFR knock-down (siR-EGFR). Three cell line, PC-9-GR-N1, RPC-9, and HCC827-Met, were experimentally established as acquired resistant cells to gefitinib. The anti-tumor effect was determined by MTS or colony formation assay. The protein expression was evaluated using Western blotting. Results: All cell lines showed the expression of EGFR protein and siR-EGFR treatment down-regulated EGFR protein in all 14 cell lines. siR-EGFR suppressed cell viability in 7 of 9 EGFR mutant cells ranged from 8.0% to 73%. PC-9-GR-N1 and RPC-9 also showed inhibition. NCI-H1670 and HCC827-Met harboured EGFR mutation but were not inhibited. Of note, PTEN was deleted in NCI-H1670 and c-MET was amplified in HCC827-Met. Cell viability of all EGFR wild-type cells was not inhibited except NCI-H411. Conclusion: Our results indicated that EGFR can be the therapeutic target of NSCLC with EGFR activation. By contrast, targeting EGFR is not appropriate strategy for tumor of which EGFR is not activated even though EGFR is expressed. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 7. doi:1538-7445.AM2012-7

Salvage treatment for metastatic penile cancer after first-line chemotherapy with paclitaxel, ifosfamide, and cisplatin: Analysis of response and survival outcomes.

340 Background: There are few effective salvage treatment options for men with advanced metastatic penile cancer. Patients who remain disease-free for 2 years after surgical removal of regional lymph node metastases are likely cured of the disease, but the survival is short for those who recur. Our objective was to estimate the efficacy of salvage treatments for metastatic penile cancer after neoadjuvant paclitaxel, ifosfamide, and cisplatin. Methods: Patients are from a 30-patient cohort who we saw between April 2000 and September 2008 presenting with stage TxN2-3M0 squamous cell carcinoma of the penis. All were treated with 1 to 4 courses of neoadjuvant paclitaxel, ifosfamide, and cisplatin chemotherapy prior to planned lymphadenectomy. For the patients who had progression or recurrence of disease, we retrospectively evaluated the salvage therapies given, response data, and survival times from the date of first progression. Results: Nineteen of the 30 patients (63.3%) had tumor progression and 17 received one or more salvage therapies. Median age at diagnosis was 57 years (range 24-72 years). The median survival from time of first progression was 5.8 months (range 3.7 to 30.9 months). Two of five patients (40%) who had received bleomycin, methotrexate, and cisplatin experienced an objective response (1 complete and 1 partial), and one (20%) developed pneumonitis. Two patients had received gemcitabine combinations without response. Two patients had received epidermal growth factor receptor-targeted therapy with gefitinib or cetuximab and cisplatin, both without response. Three patients had received chemo-radiotherapy, one with stable disease for 13.5 months and 2 with no apparent benefit. Five patients underwent salvage surgery, and they all progressed within 2 months with one case of fatal hemorrhage. Conclusions: Men with metastatic penile cancer that progresses through or recurs after front-line neoadjuvant chemotherapy have poor responses to the described salvage treatments, and median overall survival is less than 6 months. Emphasis should be placed on clinical trials for development of effective therapy in this setting.

Use of bevacizumab in metastatic colorectal cancer: report from the Mexican opinion and analysis forum on colorectal cancer treatment with bevacizumab (September 2009).

Colorectal cancer is one of the most common cancers worldwide, and although associated mortality rates in South American countries are generally among the lowest in the world, they are on the rise.The prognosis of patients diagnosed with metastatic colorectal cancer has improved markedly over the last 12 years, increasing from 5 months with best supportive care to almost 2 years with combination chemotherapy plus bevacizumab. New prognostic and predictive biomarkers have been identified to guide therapy. Prognostic markers indicate patient survival independent of therapy and include disease stage, mutational status, and carcinoembryonic antigen. More recently, predictive markers of treatment outcomes have been identified. The most studied are mutations of the KRAS and BRAF genes, which are associated with resistance to epidermal growth factor receptortargeted therapy.Tumor blood vessels have a number of structural and functional abnormalities that result in increased tumor vascularity and growth driven by angiogenesis. The anti-vascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab, which binds to and neutralizes VEGF-A, has become a central part of the treatment of metastatic colorectal cancer. The addition of bevacizumab to fluorouracil (5-FU)/leucovorin, irinotecan plus bolus 5-FU/leucovorin, or irinotecan plus infusional 5-FU/leucovorin significantly improves the overall survival of patients with previously untreated metastatic colorectal cancer. In addition, a significant increase in overall survival is seen when bevacizumab is added to oxaliplatin plus infusional 5-FU/leucovorin (FOLFOX) in patients with metastatic colorectal cancer who progressed on a non-bevacizumab-containing regimen.Although the majority of studies were performed prior to the identification of KRAS and BRAF as predictive biomarkers, subsequent analysis has shown the benefits of bevacizumab occur independently of the mutational status of these genes. In patients who have progressed on a bevacizumab-containing regimen, continuation of bevacizumab is significantly associated with an improved survival based on observational cohort studies. Surgical resection is recommended in patients with metastatic colorectal cancer where complete removal of tumors can be achieved. Perioperative chemotherapy using FOLFOX for 3 months before and 3 months after surgery is associated with a 9% improvement in 3-year survival. The use of chemotherapy in patients initially deemed unresectable has produced resection rates approaching 40%, and the addition of bevacizumab to chemotherapy in this setting is feasible, safe, and effective. In a study of 219 patients, the addition of bevacizumab to FOLFOX was associated with a significant increase in major or complete pathologic response compared with FOLFOX alone.Improvements in patient survival have changed the treatment paradigm for metastatic colorectal cancer. Newer approaches view treatment not as distinct lines of therapy but as a continuum that includes personalized treatment plans offering maintenance therapy and even drug holidays between aggressive treatment periods. This approach achieves similar efficacy outcomes with reduced toxicity, and investigation of the role of bevacizumab as maintenance therapy is ongoing.

BRAF Mutations and their Implications in Molecular Targeting Therapies for Gastrointestinal Cancers

The epidermal growth factor receptor (EGFR) has become an important therapeutic target in gastrointestinal cancers, especially in colorectal cancer. Stimulation of the EGFR activates at least five intracellular signal cascades such as RAS/RAF/MEK(mitogen-activated ERK activating kinase)/ERK(extracellular signal-regulated kinase), PI3K (phosphatidylinositol 3-kinase) /PTEN (phosphatase and tensin homolog)/AKT(v-akt murine thymoma viral oncogene homolog), STAT (signal transducer and activator of transcription), pospholipase C, and SRC/FAK(focal adhesion kinase). These either phosphorylate their target proteins in the cytoplasm or transmit signals from growth factor receptor to the nucleus, thereby initiating subsequent expression of genes that regulate cell proliferation, differentiation, angiogenesis, and survival [1] Recently, monoclonal antibodies have been developed to target EGFR and to inhibit subsequent cellular responses. They include anti-EGFR antibodies such as cetuximab (a chimeric monoclonal immunoglobulin G1 antibody), panitumumab (a fully human monoclonal immunoglobulin G2 antibody), and trastuzumab (a monoclonal antibody against human epidermal growth factor receptor-2 (HER2) as well as inhibitors of tyrosine kinase (TK) domain of EGFR or subsequent molecules such as gefitinib, erlotinib (both inhibitors of EGFR-TK), lapatinib (a dual inhibitor of HER2-TK and EGFR-TK), sunitinib (an inhibitor of the TK of various kinds of proteins), and sorafenib (an inhibitor of RAF, a downstream molecular of RAS). Among these, cetuximab, panitumumab, and trastuzumab have received the most intensive focus of research, and their efficacy has been clearly demonstrated -especially in gastric and colorectal cancer. However, it is also a fact that this efficacy is sometimes modest as objective response rates comprise at best 50% by adding trastuzumab to chemotherapy -even among HER-2 positive gastric cancer patients [2], or between 8 and 11% by cetuximab [3,4] or pamitumumab [5,6] monotherapy in colorectal cancer patients. The efficacy is thus presumed to be restricted to a certain segment of patients. Therefore, identification of predictive markers of response and resistance in performing the EGFR targeting therapies is urgently needed to stratify those patients benefiting most from them. This in turn obviate unnecessary or futile treatment and reduce health care costs, ultimately allowing treatment to be individualized.

Optimized Allele-Specific Real-Time PCR Assays for the Detection of Common Mutations in KRAS and BRAF

Mutations in the oncogenes KRAS and BRAF have been identified as prognostic factors in patients with colorectal diseases and as predictors of negative outcome in epidermal growth factor receptor-targeted therapies. Therefore, accurate mutation detection in both genes, KRAS and BRAF, is of increasing clinical relevance. We aimed at optimizing allele-specific real-time PCR assays for the detection of common mutations in KRAS and the BRAF Val600Glu mutation using allele-specific PCR primers for allelic discrimination and probes (TaqMan) for quantification. Each reaction mix contains a co-amplified internal control to exclude false-negative results. Allele-specific real-time PCR assays were evaluated on plasmid model systems providing a mutation detection limit of 10 copies of mutant DNA in proportions as low as 1% of the total DNA. Furthermore, we analyzed 125 DNA samples prepared from archived, formalin-fixed, paraffin-embedded colorectal carcinomas and compared results with those obtained from direct-sequence analysis. All mutations determined by sequence analysis could be recovered by allele-specific PCR assays. In addition, allele-specific PCR assays clearly identified three additional samples affected by a mutation. We propose these allele-specific real-time PCR assays as a low-cost and fast diagnostic tool for accurate detection of KRAS and BRAF mutations that can be applied to clinical samples.

Staphylococcus Coagulase-Positive Skin Inflammation Associated with Epidermal Growth Factor Receptor-Targeted Therapy: An Early and a Late Phase of Papulopustular Eruptions

Cutaneous eruptions, mainly papulopustular, are the most common associated side effects of epidermal growth factor receptor inhibitors (EGFRIs). This study investigated the possible role of bacterial infection in EGFRI-induced eruptions and its relation to clinical morphology. The study group consisted of all 29 patients referred for dermatologic evaluation of side effects of cetuximab or erlotinib from March 2008 to November 2009. Specimens were taken for bacterial culture from pustules in patients with grade >1 papulopustular rash and from periungual secretions in patients with paronychia. Twenty-four of 29 patients had a papulopustular reaction; five of 29 had paronychia/xerosis. Of the papulopustular eruption patients, time to rash appearance yielded two distinct groups: early-phase, median 8 days after drug initiation, located mainly on the face (n = 17) and late-phase, median ∼200 days after drug initiation, located mainly on the trunk (n = 7). Bacterial culture grew Staphylococcus aureus (SA) in seven of 13 early-phase patients tested and in all late-phase patients. Treatment consisted of topical steroids with or without topical/systemic antibiotics. All patients had a clear improvement in their cutaneous symptoms within a few days. Dose reduction or temporary discontinuation of the EGFRI was necessary in only four of 29 patients. As described in the literature, EGFRI-induced papulopustular eruption may appear early and probably is an inflammatory process with or without SA secondary infection. The papulopustular eruption may also appear as a late phase, described here for the first time, which is an infectious process with all patients being SA(+). The >50% overall incidence of SA infection in our study highlights the need for routine bacterial cultures from EGFRI-induced eruption.