Arenobufagin induces cell apoptosis by modulating the cell cycle regulator claspin and the JNK pathway in nasopharyngeal carcinoma cells

BACKGROUND

The high recurrence rate and incidence of distant metastasis of nasopharyngeal carcinoma (NPC) result in poor prognosis. It is necessary to identify natural compounds that can complement combination radiation therapy. Arenobufagin is commonly used for heart diseases and liver cancer, but its effectiveness in NPC is unclear.

STUDY DESIGN AND METHODS

The effect of arenobufagin-induced apoptosis was measured by a cell viability assay, tumorigenic assay, fluorescence assay, and Western blot assay through NPC-039 and NPC-BM cell lines. The protease array, Western blot assay, and transient transfection were used to investigate the underlying mechanism of arenobufagin-induced apoptosis. An NPC xenograft model was established to explore the antitumor activity of arenobufagin in vivo.

RESULTS

Our findings indicated that arenobufagin exerted cytotoxic effects on NPC cells, inhibiting proliferation through apoptosis activation. Downregulation of claspin was confirmed in arenobufagin-induced apoptosis. Combined treatment with arenobufagin and mitogen-activated protein kinase inhibitors demonstrated that arenobufagin induced NPC apoptosis through the c-Jun N-terminal kinases (JNK) pathway inhibition. Furthermore, arenobufagin suppressed NPC tumor proliferation in vivo.

CONCLUSION

Our results revealed the antitumor effect of arenobufagin in vitro and in vivo. Arenobufagin may have clinical utility in treating NPC due to its suppression of claspin and inhibition of the JNK pathway.

Chemotherapy and dysphagia: the good, the bad, the ugly

PURPOSE OF REVIEW

Dysphagia is a debilitating, depressing and potentially life-threatening complication in cancer patients that is likely underreported. The purpose of this review is to critically synthesize the current knowledge regarding the impact of chemotherapeutic regimens on swallowing function.

RECENT FINDINGS

Those patients with cancers involving the aerodigestive tract, head and neck cancer and oesophageal cancer are at highest risk of developing dysphagia. The most common dysphagia causing toxicity of chemotherapeutic agents is mucositis/stomatitis. The use of cisplatin is correlated with increased incidence of mucositis. Similarly, the addition of melphalan is also associated with worsening mucositis and dysphagia. In some cases of oesophageal cancer, thyroid cancer, metastatic lung or breast cancer the use of chemotherapy can improve swallow function as obstructive lesions are reduced.

SUMMARY

There is limited literature regarding the role of chemotherapy in the development or treatment of dysphagia. Most dysphagia that occurs during cancer treatment is attributable to radiation or the synergistic effect of radiation and chemotherapy. Patients with disordered swallowing prior to treatment have the greatest risk of developing posttreatment dysphagia. Studies are needed to determine whether acute inflammation associated with oropharyngeal mucositis predisposes for late dysphagia.

Chemotherapy and chemo-resistance in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) and occurs frequently in the south of China and Southeast Asian countries. Concurrent chemo-radiotherapy is one of the main treatments for NPC. Although, the combined treatment of chemo-radiotherapy produces a satisfying survival rate, the chemo-resistance arises as a big obstacle in curing recurrent NPC patients. The acquirement of chemo-resistance is usually along with a poor prognosis. So far, the mechanism of chemo-resistance in NPC has not been fully elucidated and there have not been a comprehensive review on this issue. Thus, it is of great significance to summarize the mechanisms involved in NPC chemo-resistance. In this review, the importance and limitations of chemotherapy and the mechanisms of chemo-resistances in NPC were discussed.

Beyond EGFR inhibition: multilateral combat strategies to stop the progression of head and neck cancer

Epidermal growth factor receptor (EGFR) overexpression is common in head and neck squamous cell carcinoma. Targeted therapy specifically directed towards EGFR has been an area of keen interest in head and neck cancer research, as EGFR is potentially an integration point for convergent signaling. Despite the latest advancements in cancer diagnostics and therapeutics against EGFR, the survival rates of patients with advanced head and neck cancer remain disappointing due to anti-EGFR resistance. This review article will discuss recent multilateral efforts to discover and validate actionable strategies that involve signaling pathways in heterogenous head and neck cancer and to overcome anti-EGFR resistance in the era of precision medicine. Particularly, this review will discuss in detail the issue of cancer metabolism, which has recently emerged as a novel mechanism by which head and neck cancer may be successfully controlled according to different perspectives.

South Korean researchers propose novel combination strategies for overcoming drug resistance and halting the progression of head and neck cancer (HNC). Although high levels of epidermal growth factor receptor (EGFR) protein in HNC correlate with reduced survival, patients’ response to the EGFR inhibitor cetuximab often declines rapidly after a short period of effectiveness. Hyung Kwon Byeon at Korea University College of Medicine in Seoul and colleagues review current knowledge of the mechanisms underlying cetuximab resistance. They suggest that evaluating a patient’s genetic profile and combining cetuximab with drugs that enhance the effects of inhibiting EGFR signaling pathways (with inhibitors of other EGFR family members or proteins that mediate EGFR entry to the cell nucleus, for example) as well as with agents that inhibit cancer cell metabolism could be a more effective approach for treating HNC.

Clinical immunotherapeutic approaches for the treatment of head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide, accounting for more than 550,000 cases and 380,000 deaths annually. The primary risk factors associated with HNSCC are tobacco use and alcohol consumption; nevertheless genetic predisposition and oncogenic viruses also play important roles in the development of these malignancies. The current treatments for HNSCC patients include surgery, chemotherapy, radiotherapy, and cetuximab, and combinations of these. However, these treatments are associated with significant toxicity, and many patients are either refractory to the treatment or relapse after a short period. Despite improvements in the treatment of patients with HNSCC, the clinical outcomes of those who have been treated with standard therapies have remained unchanged for over three decades and the 5-year overall survival rate in these patients remains around 40-50%. Therefore, more specific and less toxic therapies are needed in order to improve patient outcomes. The tumour microenvironment of HNSCC is immunosuppressive; therefore immunotherapy strategies that can overcome the immunosuppressive environment and produce long-term tumour immunosurveillance will have a significant therapeutic impact in these patients. This review focuses on the current immunological treatment options under investigation or available for clinical use in patients with HNSCC.

Synthesis and Characterization of Cetuximab-Docetaxel and Panitumumab-Docetaxel Antibody-Drug Conjugates for EGFR-Overexpressing Cancer Therapy

The safety and efficacy of anticancer antibody-drug conjugates (ADCs) depend on the selection of tumor-targeting monoclonal antibody (mAb), linker, and drug, as well as their specific chemical arrangement and linkage chemistry. In this study, we used a heterobifunctional cross-linker to conjugate docetaxel (DX) to cetuximab (CET) or panitumumab (PAN). The resulting ADCs were investigated for their in vitro EGFR-specific cytotoxicity and in vivo anticancer activity. Reaction conditions, such as reducing agent, time, temperature, and alkylation buffer, were optimized to yield potent and stable ADCs with consistent batch-to-batch drug-to-antibody ratios (DARs). ADCs were synthesized with DARs from 0.4 to 3.0, and all retained their EGFR affinity and specificity after modification. ADCs were sensitive to cell surface wildtype EGFR expression, demonstrating more cytotoxicity in EGFR-expressing A431 and MDA-MB-231 cell lines compared to U87MG cells. A431 tumor-bearing mice treated once weekly for four weeks with 100 mg/kg cetuximab-docetaxel ADC (C-SC-DX, DAR 2.5) showed durable anticancer responses and improved overall survival compared to the same treatment regimen with 1 mg/kg DX, 100 mg/kg CET, or a combination 1 mg/kg DX and 100 mg/kg CET. New treatment options are emerging for patients with both wild-type and mutated EGFR-overexpressing cancers, and these studies highlight the potential role of EGFR-targeted ADC therapies as a promising new treatment option.

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Method for Quantitative Analysis of Platinum in Plasma, Urine, and Tissues

Cisplatin, a platinum chemotherapeutic, is one of the most commonly used chemotherapeutic agents for many solid tumors. In this work, we developed and validated an inductively coupled plasma mass spectrometry (ICP-MS) method for quantitative determination of platinum levels in rat urine, plasma, and tissue matrices including liver, brain, lungs, kidney, muscle, heart, spleen, bladder, and lymph nodes. The tissues were processed using a microwave accelerated reaction system (MARS) system prior to analysis on an Agilent 7500 ICP-MS. According to the Food and Drug Administration guidance for industry, bioanalytical validation parameters of the method, such as selectivity, accuracy, precision, recovery, and stability were evaluated in rat biological samples. Our data suggested that the method was selective for platinum without interferences caused by other presenting elements, and the lower limit of quantification was 0.5 ppb. The accuracy and precision of the method were within 15% variation and the recoveries of platinum for all tissue matrices examined were determined to be 85-115% of the theoretical values. The stability of the platinum-containing solutions, including calibration standards, stock solutions, and processed samples in rat biological matrices was investigated. Results indicated that the samples were stable after three cycles of freeze-thaw and for up to three months.

Emerging drugs for head and neck cancer

INTRODUCTION

Despite improvements in treatment, survival rates of head and neck squamous cell carcinoma (HNSCC) are stagnant. The existing chemotherapeutic agents are non-selective and associated with toxicities. Combinations of the only the US FDA-approved epidermal growth factor receptor (EGFR)-targeted agent, cetuximab, with chemotherapy or radiation improves overall survival. However, the response rates to cetuximab are modest. Thus, there is an urgent need for new agents that can be safely integrated into current treatment regimens to improve outcome.

AREAS COVERED

Current EGFR-targeted drugs under clinical development include mAbs and tyrosine kinase inhibitors. The modest efficacy of these drugs implicates intrinsic or acquired resistance. Novel molecular agents inhibiting alternative targets to overcome anti-EGFR resistance in HNSCC are under investigation. Gene therapy and immunotherapy are also promising strategies to improve efficacy and reduce toxicity.

EXPERT OPINION

To date, only six drugs have been FDA-approved for the treatment of head and neck cancer. Cetuximab is the only approved molecular targeting agent for HNSCC and despite ubiquitous expression of EGFR in HNSCC tumors, clinical responses are limited. Genetic and epigenetic characterization of HNSCC tumors, coupled with improved preclinical models, should facilitate the development of more effective drugs.

Chemoradiotherapy with or without panitumumab in patients with unresected, locally advanced squamous-cell carcinoma of the head and neck (CONCERT-1): a randomised, controlled, open-label phase 2 trial

BACKGROUND

Panitumumab is a fully human monoclonal antibody that targets EGFR. We aimed to compare chemoradiotherapy plus panitumumab with chemoradiotherapy alone in patients with unresected, locally advanced squamous-cell carcinoma of the head and neck.

METHODS

In this international, open-label, randomised, controlled, phase 2 trial, we recruited patients with locally advanced squamous-cell carcinoma of the head and neck from 41 sites in nine countries worldwide. Patients aged 18 years and older with stage III, IVa, or IVb, previously untreated, measurable (≥ 10 mm for at least one dimension), locally advanced squamous-cell carcinoma of the head and neck (non-nasopharygeal) and an Eastern Cooperative Oncology Group performance status of 0-1 were randomly assigned (2:3) by an independent vendor to open-label chemoradiotherapy (three cycles of cisplatin 100 mg/m(2)) or panitumumab plus chemoradiotherapy (three cycles of intravenous panitumumab 9.0 mg/kg every 3 weeks plus cisplatin 75 mg/m(2)) using stratified randomisation with a block size of five. All patients received 70 Gy to gross tumour and 50 Gy to areas at risk for subclinical disease with standard fractionation. The primary endpoint was local-regional control at 2 years, analysed in all randomised patients who received at least one dose of their assigned protocol-specific treatment (chemotherapy, radiation, or panitumumab). The trial is closed and this is the final analysis. This trial is registered with ClinicalTrials.gov, number NCT00500760.

FINDINGS

Between Oct 26, 2007, and March 26, 2009, 153 patients were enrolled and 150 received treatment (63 in the chemoradiotherapy group and 87 in the panitumumab plus chemoradiotherapy group). Local-regional control at 2 years was 68% (95% CI 54-78) in the chemoradiotherapy group and 61% (50-71) in the panitumumab plus chemoradiotherapy group. The most frequent grade 3-4 adverse events were dysphagia (17 [27%] of 63 patients in the chemoradiotherapy group vs 35 [40%] of 87 in the panitumumab plus chemoradiotherapy group), mucosal inflammation (15 [24%] vs 48 [55%]), and radiation skin injury (eight [13%] vs 27 [31%]). Serious adverse events were reported in 20 (32%) of 63 patients in the chemoradiotherapy group and in 37 (43%) of 87 patients in the panitumumab plus chemoradiotherapy group.

INTERPRETATION

In patients with locally advanced squamous-cell carcinoma of the head and neck, the addition of panitumumab to standard fractionation radiotherapy and cisplatin did not confer any benefit, and the role of EGFR inhibition in these patients needs to be reassessed.

FUNDING

Amgen.

Preoperative chemoradiation therapy in combination with panitumumab for patients with resectable esophageal cancer: the PACT study

PURPOSE

Preoperative chemoradiation therapy (CRT) has become the standard treatment strategy for patients with resectable esophageal cancer. This multicenter phase 2 study investigated the efficacy of the addition of the epidermal growth factor receptor (EGFR) inhibitor panitumumab to a preoperative CRT regimen with carboplatin, paclitaxel, and radiation therapy in patients with resectable esophageal cancer.

METHODS AND MATERIALS

Patients with resectable cT1N1M0 or cT2-3N0 to -2M0 tumors received preoperative CRT consisting of panitumumab (6 mg/kg) on days 1, 15, and 29, weekly administrations of carboplatin (area under the curve [AUC] = 2), and paclitaxel (50 mg/m(2)) for 5 weeks and concurrent radiation therapy (41.4 Gy in 23 fractions, 5 days per week), followed by surgery. Primary endpoint was pathologic complete response (pCR) rate. We aimed at a pCR rate of more than 40%. Furthermore, we explored the predictive value of biomarkers (EGFR, HER 2, and P53) for pCR.

RESULTS

From January 2010 until December 2011, 90 patients were enrolled. Patients were diagnosed predominantly with adenocarcinoma (AC) (80%), T3 disease (89%), and were node positive (81%). Three patients were not resected due to progressive disease. The primary aim was unmet, with a pCR rate of 22%. Patients with AC and squamous cell carcinoma reached a pCR of 14% and 47%, respectively. R0 resection was achieved in 95% of the patients. Main grade 3 toxicities were rash (12%), fatigue (11%), and nonfebrile neutropenia (11%). None of the biomarkers was predictive for response.

CONCLUSIONS

The addition of panitumumab to CRT with carboplatin and paclitaxel was safe and well tolerated but could not improve pCR rate to the preset criterion of 40%.

Improving therapeutic ratio in head and neck cancer with adjuvant and cisplatin-based treatments

Advanced head and neck cancers are difficult to manage despite the large treatment arsenal currently available. The multidisciplinary effort to increase disease-free survival and diminish normal tissue toxicity was rewarded with better locoregional control and sometimes fewer side effects. Nevertheless, locoregional recurrence is still one of the main reasons for treatment failure. Today, the standard of care in head and neck cancer management is represented by altered fractionation radiotherapy combined with platinum-based chemotherapy. Targeted therapies as well as chronotherapy were trialled with more or less success. The aim of the current work is to review the available techniques, which could contribute towards a higher therapeutic ratio in the treatment of advanced head and neck cancer patients.

Current challenges and clinical investigations of epidermal growth factor receptor (EGFR)- and ErbB family-targeted agents in the treatment of head and neck squamous cell carcinoma (HNSCC)

Overexpression of the epidermal growth factor receptor (EGFR) is a common characteristic of head and neck squamous cell carcinomas (HNSCC). Cetuximab is a chimeric anti-EGFR monoclonal antibody (mAb) with multiple approved indications in HNSCC, including with radiation therapy (RT) for locoregionally advanced disease, as monotherapy after platinum progression, and with platinum/5-fluorouracil for recurrent or metastatic disease. There remain, however, numerous unanswered questions regarding the optimal use of cetuximab in HNSCC, including patient selection, its mechanisms of action and resistance, the effect of human papillomavirus status on outcomes, its role when combined with induction chemotherapy or adjuvant radiation, and optimal management of skin toxicity and hypersensitivity reactions. In addition, a variety of other anti-EGFR agents (the multitargeted small molecule tyrosine kinase inhibitors [TKIs] lapatinib, dacomitinib, and afatinib and the anti-EGFR mAbs zalutumumab, nimotuzumab, and panitumumab) are currently under investigation in phase II and III clinical trials in different HNSCC therapeutic settings. The anti-EGFR TKI erlotinib is currently in phase III development for oral cancer prevention. Numerous other drugs are in earlier stages of development for HNSCC treatment, including novel anti-EGFR mAbs (MEHD7945A, necitumumab, and RO5083945), small-molecule TKIs (vandetanib, icotinib, and CUDC-101), EGFR antisense, various add-on therapies to radiation and chemotherapy (bevacizumab, interleukin-12, lenalidomide, alisertib, and VTX-2337), and drugs (temsirolimus, everolimus, OSI-906, dasatinib, and PX-866) intended to overcome resistance to anti-EGFR agents. Overall, a wealth of clinical trial data is expected in the coming years, with the potential to modify significantly the approach to anti-EGFR therapy for HNSCC.

Immunotherapy for head and neck cancer patients: shifting the balance

Head and neck squamous cell carcinoma is the sixth most common cancer in the western world. Over the last few decades little improvement has been made to increase the relatively low 5-year survival rate. This calls for novel and improved therapies. Here, we describe opportunities in immunotherapy for head and neck cancer patients and hurdles yet to be overcome. Viruses are involved in a subset of head and neck squamous cell carcinoma cases. The incidence of HPV-related head and neck cancer is increasing and is a distinctly different disease from other head and neck carcinomas. Virus-induced tumors express viral antigens that are good targets for immunotherapeutic treatment options. The type of immunotherapeutic treatment, either active or passive, should be selected depending on the HPV status of the tumor and the immune status of the patient.

[Immunotherapy of head and neck cancer. Current developments]

In order to improve the prognosis for patients with head and neck squamous cell cancer (HNSCC) the introduction of new therapeutic strategies is necessary. The concept of immunotherapy has been applied and improved for several years and recent studies have used tumor-specific antigens which facilitates targeted oncologic therapy. However, immunotherapy is hampered by the fact that immunosuppressive mechanisms are pronounced and relevant effector cells are suppressed, especially in patients with HNSCC. Successful immunotherapy could induce an antitumor immune response by restitution of these cell populations. Current anti-tumor immunotherapy includes unspecific immune stimulation, genetic modification of tumor and immune cells, the use of monoclonal antibodies, e.g. cetuximab, adoptive cell transfer and tumor vaccination. In the future, these biologic therapies alone or in combination with conventional therapeutic regimens could present a valuable therapeutic option for HNSCC patients.

New approaches to EGFR inhibition for locally advanced or metastatic squamous cell carcinoma of the head and neck (SCCHN)

Despite recent advances in radiotherapy and chemotherapy, survival rates for squamous cell carcinoma of the head and neck (SCCHN) have remained poor. The focus of SCCHN therapy has more recently shifted to the molecular level, particularly the epidermal growth factor receptor (EGFR/ErbB) pathway. Several agents that target the EGFR pathway, including monoclonal antibodies and tyrosine kinase inhibitors, are under investigation for SCCHN. Searches of PubMed and results of key oncology congresses were performed to identify relevant articles and abstracts. The EGFR-targeted monoclonal antibody cetuximab is approved for the treatment of locally advanced SCCHN in combination with radiotherapy, for first-line treatment of recurrent or metastatic SCCHN in combination with platinum-based chemotherapy and 5-fluorouracil, and for recurrent or metastatic SCCHN following progression with platinum-based chemotherapy. Other investigational EGFR-targeted monoclonal antibodies (e.g., panitumumab, nimotuzumab, zalutumumab) are in clinical development for SCCHN. Inhibition of the tyrosine kinase domain of EGFR has also been explored as a therapeutic approach in SCCHN using small-molecule reversible inhibitors, such as gefitinib and erlotinib. However, a key challenge in SCCHN is the development of resistance, and strategies are being pursued to delay or overcome resistance to EGFR-targeted agents. These strategies include development of agents that inhibit multiple ErbB receptors simultaneously (e.g., lapatinib) or that bind multiple ErbB family receptors irreversibly (e.g., afatinib, PF-00299804) and investigation of combinations of agents that target multiple pathways implicated in the pathogenesis of SCCHN. Ongoing large clinical trials are evaluating these emerging agents and combinations for the treatment of SCCHN.

EGFR Monoclonal Antibodies in the Treatment of Squamous Cell Carcinoma of the Head and Neck: A View beyond Cetuximab

Squamous cell carcinoma of the head and neck (SCCHN) is a prevalent disease both in the United States and worldwide with an overall poor prognosis, in part due to limited activity of existing therapy. Primary therapy is largely dictated by the anatomical origin of the cancer and whether distant disease is present. Many patients with localized disease are treated with chemoradiotherapy, either in the definitive or adjuvant setting, and those with metastatic disease are treated with palliative chemotherapy. The chemotherapy used in SCCHN can be toxic, whether given with radiation or alone. The epidermal growth factor receptor (EGFR) is highly expressed in SCCHN and serves as a logical therapeutic target. EGFR-directed monoclonal antibodies (MoAbs) have higher activity in SCCHN than small molecule tyrosine kinase inhibitors. Cetuximab, a widely studied EGFR MoAb, is FDA approved in the metastatic setting, as well as with radiation for locally advanced disease. Despite improvements in survival when cetuximab is incorporated with chemotherapy for metastatic disease, the prognosis of patients remains poor. Novel EGFR MoAbs are being developed with the goal of improving efficacy and tolerability. This paper will summarize the use of EGFR-directed MoAbs in treating SCCHN with a focus on novel agents being tested.

The use of epidermal growth factor receptor monoclonal antibodies in squamous cell carcinoma of the head and neck

Targeting of the EGF receptor (EGFR) has become a standard of care in several tumor types. In squamous cell carcinoma of the head and neck, monoclonal antibodies directed against EGFR have become a regular component of therapy for curative as well as palliative treatment strategies. These agents have anti-tumor efficacy as a single modality and have demonstrated synergistic tumor killing when combined with radiation and/or chemotherapy. While cetuximab has been the primary anti-EGFR monoclonal antibody used in the US, variant anti-EGFR monoclonal antibodies have been used in several clinical studies and shown benefit with improved toxicity profiles. Next generation anti-EGFR monoclonal antibodies may demonstrate multi-target epitope recognition, enhanced immune cell stimulation, or conjugation with radioisotopes in order to improve clinical outcomes. Identification of the specific patient subset that would optimally benefit from anti-EGFR monoclonal antibodies remains an elusive goal.

Antiepidermal growth factor receptor therapy in squamous cell carcinoma of the head and neck

Squamous cell carcinoma of head and neck (SCCHN) is the most common neoplasm of the upper aerodigestive tract. In this paper, we attempt to summarize the role and applications of the epidermal growth factor receptor (EGFR) inhibitors monoclonal antibodies (moAbs) and tyrosine kinase inhibitors (TKIs) locally advanced as well as metastatic SCCHN. Targeted therapy in SCCHN is now incorporated in the first-line regimes for advanced disease. Novel targeted agents, including the EGFR antibody, cetuximab, have been approved for use as single agents or in combination with radiation therapy or chemotherapy in treatment of recurrent metastatic or locally advanced SCCHN. Refractory mechanisms that bypass the pathway of EGFR inhibitors activity are identified explaining resistance to targeted therapy. Strategies of cotargeting EGFR and other pathways are under investigation. Examples of targeted therapy being used include mammalian target of rapamycin (mtor) inhibitors, antivascular endothelial growth factor (VEGF) moAb, and other inhibitors. We will be focusing our paper on the preclinical and clinical aspects of EGFR inhibition in SCCHN and touch upon other targeted therapies in application.

Treatment of recurrent metastatic head and neck cancer: focus on cetuximab

EGFR belongs to the ErbB family of receptor tyrosine kinases and is associated with worse prognosis in head and neck squamous cell carcinoma (HNSCC). Cetuximab is a monoclonal antibody to the extracellular domain of EGFR and inhibits its downstream actions via multiple mechanisms. Besides its proven efficacy in locally advanced and incurable HNSCC, cetuximab has the distinct advantage of having a relatively tolerable side effect profile and not potentiating radiation toxicity. Though therapies for advanced HNSCC are evolving, locoregional recurrence and/or distant metastases occur in a large percentage of patients. Though some patients can be salvaged with surgery or radiation therapy, the majority are incurable, and are treated palliatively with systemic therapy. In the setting of first line therapy for recurrent/metastatic HNSCC, the EXTREME trial provided level 1 evidence that cetuximab improves overall survival when combined with cisplatinum and 5 FU. Following progression on first line chemotherapy, several phase II trials suggest that cetuximab monotherapy is a reasonable choice in this setting. Future studies should concentrate on clinical and molecular markers that may allow more personalized approaches to treating HNSCC, and combining EGFR inhibitors with other agents in a synergistic approach.

Swallowing dysfunction in cancer patients

PURPOSE

Dysphagia (swallowing dysfunction) is a debilitating, depressing, and potentially life-threatening complication in cancer patients that is likely underreported. The present paper is aimed to review relevant dysphagia literature between 1990 and 2010 with a focus on assessment tools, prevalence, complications, and impact on quality of life in patients with a variety of different cancers, particularly in those treated with curative chemoradiation for head and neck cancer.

METHODS

The literature search was limited to the English language and included both MEDLINE/PubMed and EMBASE. The search focused on papers reporting dysphagia as a side effect of cancer and cancer therapy. We identified relevant literature through the primary literature search and by articles identified in references.

RESULTS

A wide range of assessment tools for dysphagia was identified. Dysphagia is related to a number of factors such as direct impact of the tumor, cancer resection, chemotherapy, and radiotherapy and to newer therapies such as epidermal growth factor receptor inhibitors. Concomitant oral complications such as xerostomia may exacerbate subjective dysphagia. Most literature focuses on head and neck cancer, but dysphagia is also common in other types of cancer.

CONCLUSIONS

Swallowing impairment is a clinically relevant acute and long-term complication in patients with a wide variety of cancers. More prospective studies on the course of dysphagia and impact on quality of life from baseline to long-term follow-up after various treatment modalities, including targeted therapies, are needed.

Novel targeted therapies in head and neck cancer

INTRODUCTION

Molecularly targeted therapy, with the potential for increased selectivity and fewer adverse effects, hold promise in the treatment of HNSCC.

AREAS COVERED

Targeted agents for HNSCC expected to improve the effectiveness of current therapy including HER family, Src-family kinase, cell cycle, MET, AKT, HDAC, PARP, COX inhibitors and antiangiogenesis.

EXPERT OPINION

Epidermal growth factor receptor inhibitors are established in HNSCC and the need now is to find biomarkers for sensitivity to better select patients. Moreover, other pathway inhibitors hold significant promise and are being tested in clinical trials. Angiogenesis inhibition is likely to yield only modest efficacy alone but may augment existing standards. Lastly, one clinical arena where targeted therapies may find secure purchase is in the adjuvant or prevention setting where minimal or preneoplastic disease can be affected by inhibition of a single or few targets.

Monoclonal antibodies and Fc fragments for treating solid tumors

Advances in biotechnology, better understanding of pathophysiological processes, as well as the identification of an increasing number of molecular markers have facilitated the use of monoclonal antibodies and Fc fragments in various fields in medicine. In this context, a rapidly growing number of these substances have also emerged in the field of oncology. This review will summarize the currently approved monoclonal antibodies used for the treatment of solid tumors with a focus on their clinical application, biological background, and currently ongoing trials.

A retrospective study of induction chemotherapy with docetaxel, cisplatinum, and 5-fluorouracil followed by concurrent radiotherapy with cetuximab in locally advanced head and neck cancer

BACKGROUND

The objective was to study the results of induction chemotherapy followed by external beam radiation therapy with concurrent cetuximab in the treatment of locally advanced head and neck cancer.

METHODS

Seventeen patients with stage III or IV squamous cell carcinomas of the head and neck who received docetaxel, cisplatinum, and 5-fluorouracil followed by radiation therapy with concurrent cetuximab were retrospectively analyzed. All radiation was delivered with image-guided intensity-modulated radiation treatments. Primary end points analyzed were local control and overall survival.

RESULTS

With a median follow-up of 17 months, the approximate 2-year local control was 85%, with overall survival being 91%. At time of last follow-up, only 1 death was observed, with the cause of death unknown. Two local failures were observed, and the patients were under active management for their recurrences at time of last follow-up. No distant metastatic failures were noted among the patients.

CONCLUSIONS

Induction chemotherapy with docetaxel, cisplatinum, and 5-fluorouracil followed by concurrent radiation with cetuximab provides for excellent locoregional control of disease. Future prospective studies can better establish the efficacy of this treatment regimen to current favored protocols.

Radiotherapy and "new" drugs-new side effects?

BACKGROUND AND PURPOSE

Targeted drugs have augmented the cancer treatment armamentarium. Based on the molecular specificity, it was initially believed that these drugs had significantly less side effects. However, currently it is accepted that all of these agents have their specific side effects. Based on the given multimodal approach, special emphasis has to be placed on putative interactions of conventional cytostatic drugs, targeted agents and other modalities. The interaction of targeted drugs with radiation harbours special risks, since the awareness for interactions and even synergistic toxicities is lacking. At present, only limited is data available regarding combinations of targeted drugs and radiotherapy. This review gives an overview on the current knowledge on such combined treatments.

MATERIALS AND METHODS

Using the following MESH headings and combinations of these terms pubmed database was searched: Radiotherapy AND cetuximab/trastuzumab/panitumumab/nimotuzumab, bevacizumab, sunitinib/sorafenib/lapatinib/gefitinib/erlotinib/sirolimus, thalidomide/lenalidomide as well as erythropoietin. For citation crosscheck the ISI web of science database was used employing the same search terms.

RESULTS

Several classes of targeted substances may be distinguished: Small molecules including kinase inhibitors and specific inhibitors, antibodies, and anti-angiogenic agents. Combination of these agents with radiotherapy may lead to specific toxicities or negatively influence the efficacy of RT. Though there is only little information on the interaction of molecular targeted radiation and radiotherapy in clinical settings, several critical incidents are reported.

CONCLUSIONS

The addition of molecular targeted drugs to conventional radiotherapy outside of approved regimens or clinical trials warrants a careful consideration especially when used in conjunction in hypo-fractionated regimens. Clinical trials are urgently needed in order to address the open question in regard to efficacy, early and late toxicity.

Single-arm phase II study of multiagent concurrent chemoradiotherapy and gefitinib in locoregionally advanced squamous cell carcinoma of the head and neck

BACKGROUND

This phase II study tested the addition of the oral epidermal growth factor receptor gefitinib to multiagent concurrent chemoradiotherapy regimen in head and neck squamous cell cancer (HNSCC).

METHODS

Patients with stage III-IV HNSCC received hyperfractionated radiation (72-74.4 Gy at 120 cGy twice daily), with concurrent 96-hour infusions of cisplatin 20 mg/m(2) /day and fluorouracil 1000 mg/m(2) /day given during weeks 1 and 4. Daily gefitinib 250 mg was started on day 1 of radiation and continued for 2 years. Results were retrospectively compared with our previous study using identical chemoradiotherapy without gefitinib.

RESULTS

Sixty patients were enrolled in the study; 80% had stage IV disease and 68% had oropharyngeal primary tumors. The full course of gefitinib was not tolerated by 42%; there were 5 treatment-related deaths (8%). With a median follow-up of 54 months, 2- and 3-year overall survival estimates were 80% and 71%, respectively. Projected distant metastatic control at 2 and 3 years was 88%. When compared with our historical cohort, acute toxicities including renal dysfunction and unplanned rehospitalization were worse in the study patients. Projected outcome estimates did not differ between the 2 cohorts.

CONCLUSIONS

Addition of gefitinib to concurrent chemoradiotherapy was difficult to complete, did not improve outcomes, and increased toxicity.

Protein-intrinsic and signaling network-based sources of resistance to EGFR- and ErbB family-targeted therapies in head and neck cancer

Agents targeting EGFR and related ErbB family proteins are valuable therapies for the treatment of many cancers. For some tumor types, including squamous cell carcinomas of the head and neck (SCCHN), antibodies targeting EGFR were the first protein-directed agents to show clinical benefit, and remain a standard component of clinical strategies for management of the disease. Nevertheless, many patients display either intrinsic or acquired resistance to these drugs; hence, major research goals are to better understand the underlying causes of resistance, and to develop new therapeutic strategies that boost the impact of EGFR/ErbB inhibitors. In this review, we first summarize current standard use of EGFR inhibitors in the context of SCCHN, and described new agents targeting EGFR currently moving through pre-clinical and clinical development. We then discuss how changes in other transmembrane receptors, including IGF1R, c-Met, and TGF-β, can confer resistance to EGFR-targeted inhibitors, and discuss new agents targeting these proteins. Moving downstream, we discuss critical EGFR-dependent effectors, including PLC-γ; PI3K and PTEN; SHC, GRB2, and RAS and the STAT proteins, as factors in resistance to EGFR-directed inhibitors and as alternative targets of therapeutic inhibition. We summarize alternative sources of resistance among cellular changes that target EGFR itself, through regulation of ligand availability, post-translational modification of EGFR, availability of EGFR partners for hetero-dimerization and control of EGFR intracellular trafficking for recycling versus degradation. Finally, we discuss new strategies to identify effective therapeutic combinations involving EGFR-targeted inhibitors, in the context of new system level data becoming available for analysis of individual tumors.

Integrating systemic agents into multimodality treatment of locally advanced head and neck cancer

Although highly debated in the 1980s, randomized clinical trials have provided undeniable evidence that systemic chemotherapy, as part of a multimodality treatment collaboration, is effective in improving survival, organ preservation and local-regional control in locally advanced head and neck cancer (HNC). We are entering an exciting period in which new chemotherapy agents, new paradigms of treatment, new surgical and radiation technology, and new prognostic factors are rapidly becoming available. Information on how to integrate these new tools and on how they affect long-term outcomes are lacking, making decision making and treatment planning more difficult. With unprecedented survival and the changing demographics of HNC we must now consider long-term consequences in addition to survival and local and regional control as important factors in therapeutic decision making. The availability of different treatment plans that incorporate systemic chemotherapy, radiotherapy and surgery give us many tools with which to craft a treatment for each individual patient. Today, in this exciting and chaotic period, a multidisciplinary and collaborative approach for each HNC patient at the start of decision making and planning is a necessity and the absolute standard of medical treatment for excellent patient care.

New advances in targeted therapies for squamous cell carcinoma of the head and neck

Several molecular pathways are deregulated and activated in squamous cell carcinoma of the head and neck making this disease attractive for targeted molecular therapies. Cetuximab, a monoclonal antibody that binds to the epidermal growth factor receptor, improves the overall survival when combined with radiation therapy or chemotherapy. Novels agents targeting different molecular pathways in squamous cell carcinoma of the head and neck are currently under development. Among them, dual (epidermal growth factor receptor/human epidermal growth factor receptor-2) or pan-human epidermal growth factor receptor inhibitors and drugs that target the insulin growth factor-1 receptor, the MET receptor, or the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway have shown either interesting preclinical activity or promising preliminary clinical efficacy. Angiogenesis inhibitors should be used with caution in squamous cell carcinoma of the head and neck due to the risk of tumor bleeding. However, only a minority of patients seems to benefit from these new approaches. Understanding the primary and acquired resistance mechanisms to predict the treatment efficacy is of crucial importance to allow a better patient selection.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Targeting epidermal growth factor receptor in the treatment of non-small-cell lung cancer

IMPORTANCE OF THE FIELD

The management of non-small-cell lung cancer (NSCLC) has undergone a paradigm shift in the last decade, with the survival advantage demonstrated by the incorporation of anti-epidermal growth factor receptor (EGFR) agents to the standard treatment of advanced/metastatic NSCLC.

AREAS COVERED IN THIS REVIEW

We review the existing data regarding the distinct anti-EGFR agents in the NSCLC treatment and the potential role of the investigated biomarkers in the clinical outcome.

WHAT THE READER WILL GAIN

Tyrosine kinase inhibitors have been used in first-line, second-line and more settings with extremely good results in a subgroup of patients. Cetuximab remains the only anti-EGFR monoclonal antibody to show survival benefit when combined with a cytotoxic agent in the front-line setting. Anti-EGFR treatment is associated with a dramatic clinical benefit in a subgroup of patients, emphasizing the importance of customizing treatment. Several biomarkers have been investigated for their predictive or prognostic value. Validation of identification of biomarkers remains a focus of intense research that may ultimately guide therapeutic decision making, as none of these is considered ideal to discriminate responding from non-responding patients. However, the current evidence of the EGFR mutation analysis from a recent randomised trial suggests that EGFR mutation analysis is quite a good predictive marker for responsiveness to anti-EGFR TKIs. Moreover, the identification of surrogate markers to indicate optimal activity of the anti-EGFR agent is also needed. This review article provides data from large clinical trials using anti-EGFR agents and correlates these results with the tested biomarkers.

TAKE HOME MESSAGE

EGFR inhibition has shown very encouraging results and has improved the outcome of the NSCLC treatment. However, a plateau of significant clinical benefit seems to have been reached and we believe that the time to move away from the traditional treatment approach to more individualizing therapies has come.

Epidermal growth factor receptor inhibitor gefitinib added to chemoradiotherapy in locally advanced head and neck cancer

PURPOSE

Assess efficacy and toxicity of gefitinib, an epidermal growth factor receptor (EGFR) inhibitor, added to, and in maintenance after, concurrent chemoradiotherapy (CCRT) in locally advanced head and neck cancer (LA-HNC) and correlate outcomes with EGFR gene copy number alterations.

PATIENTS AND METHODS

Patients with stage III to IV LA-HNC received two cycles of carboplatin/paclitaxel induction chemotherapy (IC) followed by split-course CCRT with fluorouracil, hydroxyurea, twice daily radiotherapy (FHX), and gefitinib (250 mg daily) followed by continued gefitinib for 2 years total. The primary end point was complete response (CR) rate after CCRT. EGFR gene copy number was assessed by fluorescent in situ hybridization.

RESULTS

Sixty-nine patients (66 with stage IV disease, 37 with oropharynx primary tumors, and 67 with performance status 0 to 1) were enrolled with a median age of 55 years. Predominant grade 3 or 4 toxicities during IC and CCRT were neutropenia (n = 20) and in-field mucositis (n = 59) and dermatitis (n = 23), respectively. CR rate after CCRT was 90%. After median follow-up of 3.5 years, 4-year overall, progression-free, and disease-specific survival rates were 74%, 72%, and 89%, respectively. To date, one patient has developed a second primary tumor in the aerodigestive tract. In 31 patients with available tissue, high EGFR gene copy number was associated with worse overall survival (P = .02).

CONCLUSION

Gefitinib can be administered with FHX and as maintenance therapy for at least 2 years, demonstrating CR and survival rates that compare favorably with prior experience. High EGFR gene copy number may be associated with poor outcome in patients with LA-HNC treated with this regimen.

Molecular targeted therapies in head and neck cancer--an update of recent developments-

Targeted therapies have made their way into clinical practice during the past decade. They have caused a major impact on the survival of cancer patients in many areas of clinical oncology and hematology. Indeed, in some hematologic malignancies, such as chronic myelogenous leukemia or non-Hodgkin's lymphomas, biologicals and antibodies specifically designed to target tumour-specific proteins have revolutionized treatment standards. In solid tumours, new drugs targeting EGF- or VEGF- receptors are now approved and are entering clinical practise for treatment of colon, lung, kidney and other cancers, either alone or in combination with conventional treatment approaches. Recent data have now shown that molecular targeted therapy might display efficacy in patients with head and neck squamous cell carcinoma (HNSCC) as well. The evaluated biologicals are generally well tolerated from HNSCC patients, who usually have the burden of multiple co-morbidities that interfere with conventional systemic treatment options. Therefore, molecular targeted therapies offer new treatment options even for heavily pretreated and seriously ill patients usually unable to tolerate chemotherapy or radiation therapy. The two most promising and advanced strategies are the blockage of growth-factor based cellular signalling and interference with angiogenesis-related pathways. But inhibitors of alternative targets, such as Scr and proteasomes, have already been evaluated in early clinical trials with HNSCC patients.