Integrating epidermal growth factor receptor assay with clinical parameters improves risk classification for relapse and survival in head-and-neck squamous cell carcinoma

Dual-targeted NAMPT inhibitors as a progressive strategy for cancer therapy

In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the nicotinamide adenine dinucleotide (NAD+) synthesis pathway catalyzing the condensation of nicotinamide (NAM) with 5-phosphoribosyl-1-pyrophosphate (PRPP) to produce nicotinamide mononucleotide (NMN). Given the pivotal role of NAD+ in a range of cellular functions, including DNA synthesis, redox reactions, cytokine generation, metabolism, and aging, NAMPT has become a promising target for many diseases, notably cancer. Therefore, various NAMPT inhibitors have been reported and classified as first and second-generation based on their chemical structures and design strategies, dual-targeted being one. However, most NAMPT inhibitors suffer from several limitations, such as dose-dependent toxicity and poor pharmacokinetic properties. Consequently, there is no clinically approved NAMPT inhibitor. Hence, research on discovering more effective and less toxic dual-targeted NAMPT inhibitors with desirable pharmacokinetic properties has drawn attention recently. This review summarizes the previously reported dual-targeted NAMPT inhibitors, focusing on their design strategies and advantages over the single-targeted therapies.

Targeting Epidermal Growth Factor Receptor for Cancer Treatment: Abolishing Both Kinase-Dependent and Kinase-Independent Functions of the Receptor

Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, is activated by ligand binding, overexpression, or mutation. It is well known for its tyrosine kinase-dependent oncogenic activities in a variety of human cancers. A large number of EGFR inhibitors have been developed for cancer treatment, including monoclonal antibodies, tyrosine kinase inhibitors, and a vaccine. The EGFR inhibitors are aimed at inhibiting the activation or the activity of EGFR tyrosine kinase. However, these agents have shown efficacy in only a few types of cancers. Drug resistance, both intrinsic and acquired, is common even in cancers where the inhibitors have shown efficacy. The drug resistance mechanism is complex and not fully known. The key vulnerability of cancer cells that are resistant to EGFR inhibitors has not been identified. Nevertheless, it has been increasingly recognized in recent years that EGFR also possesses kinase-independent oncogenic functions and that these noncanonical functions may play a crucial role in cancer resistance to EGFR inhibitors. In this review, both kinase-dependent and -independent activities of EGFR are discussed. Also discussed are the mechanisms of actions and therapeutic activities of clinically used EGFR inhibitors and sustained EGFR overexpression and EGFR interaction with other receptor tyrosine kinases to counter the EGFR inhibitors. Moreover, this review discusses emerging experimental therapeutics that have shown potential for overcoming the limitation of the current EGFR inhibitors in preclinical studies. The findings underscore the importance and feasibility of targeting both kinase-dependent and -independent functions of EGFR to enhance therapeutic efficacy and minimize drug resistance. SIGNIFICANCE STATEMENT: EGFR is a major oncogenic driver and therapeutic target, but cancer resistance to current EGFR inhibitors remains a significant unmet clinical problem. This article reviews the cancer biology of EGFR as well as the mechanisms of actions and the therapeutic efficacies of current and emerging EGFR inhibitors. The findings could potentially lead to development of more effective treatments for EGFR-positive cancers.

Influence of EGF and pro-NGF on EGFR/SORTILIN interaction and clinical impact in head and neck squamous cell carcinoma

Head and Neck Squamous Cell Carcinoma (HNSCC) remains a cancer with a poor prognosis, with a 5-year survival rate of less than 50%. Although epidermal growth factor receptor (EGFR) is almost always overexpressed, targeted anti-EGFR therapies have modest efficacy and are mainly used in palliative care. Growth factors such as Nerve Growth Factor (NGF) and its precursor proNGF have been shown in our laboratory to play a role in tumor growth and aggressiveness. Interestingly, an interaction between Sortilin, a proNGF receptor, and EGFR has been observed. This interaction appears to interfere with the pro-oncogenic signaling of EGF and modulate the membrane expression of EGFR. The aim of this study was to characterize this interaction biologically, to assess its impact on clinical prognosis and to analyze its role in the cellular trafficking of EGFR. Using immunohistochemical staining on tumor sections from patients treated at our university center and PLA (Proximity Ligation Assay) labeling, we showed that Sortilin expression is significantly associated with reduced 5-year survival. However, when Sortilin was associated with EGFR, this association was not found. Using the Cal-27 and Cal-33 cancer cell lines, we observed that proNGF reduces the effects of EGF on cell growth by inducing the internalization of its receptor. These results therefore suggest a regulatory role for Sortilin in the degradation or renewal of EGFR on the membrane. It would be interesting in future work to show the intracellular fate of EGFR and the role of (pro)neurotrophins in these mechanisms.

Recent findings on the impact of ErbB receptors status on prognosis and therapy of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer type, has often an aggressive course and is poorly responsive to current therapeutic approaches, so that 5-year survival rates for patients diagnosed with advanced disease is lower than 50%. The Epidermal Growth Factor Receptor (EGFR) has emerged as an established oncogene in HNSCC. Indeed, although HNSCCs are a heterogeneous group of cancers which differ for histological, molecular and clinical features, EGFR is overexpressed or mutated in a percentage of cases up to about 90%. Moreover, aberrant expression of the other members of the ErbB receptor family, ErbB2, ErbB3 and ErbB4, has also been reported in variable proportions of HNSCCs. Therefore, an increased expression/activity of one or multiple ErbB receptors is found in the vast majority of patients with HNSCC. While aberrant ErbB signaling has long been known to play a critical role in tumor growth, angiogenesis, invasion, metastatization and resistance to therapy, more recent evidence has revealed its impact on other features of cancer cells' biology, such as the ability to evade antitumor immunity. In this paper we will review recent findings on how ErbB receptors expression and activity, including that associated with non-canonical signaling mechanisms, impacts on prognosis and therapy of HNSCC.

EGFR Mutations in Head and Neck Squamous Cell Carcinoma

EGFR is a prototypical receptor tyrosine kinase that is overexpressed in multiple cancers including head and neck squamous cell carcinoma (HNSCC). The standard of care for HNSCC remains largely unchanged despite decades of research. While EGFR blockade is an attractive target in HNSCC patients and anti-EGFR strategies including monoclonal antibodies and kinase inhibitors have shown some clinical benefit, efficacy is often due to the eventual development of resistance. In this review, we discuss how the acquisition of mutations in various domains of the EGFR gene not only alter drug binding dynamics giving rise to resistance, but also how mutations can impact radiation response and overall survival in HNSCC patients. A better understanding of the EGFR mutational landscape and its dynamic effects on treatment resistance hold the potential to better stratify patients for targeted therapies in order to maximize therapeutic benefits.

Nuclear HER3 expression improves the prognostic stratification of patients with HER1 positive advanced laryngeal squamous cell carcinoma

Background

Compared to the other members of human epidermal growth factor family receptors (HER), the role of HER3 has not been well defined in laryngeal cancer. The predictive and prognostic role of HER3 has been the focus of clinical attention but the research findings are contradictory, especially in laryngeal squamous cell carcinoma (LSCC). The variable localization of HER3 within cancer cells and the role of HER3 in primary and acquired resistance to HER1-targeted therapies remain unclear.

Methods

We performed a retrospective analysis of two cohorts of 66 homogeneous consecutive untreated primary advanced LSCC patients, in which co-expression of HER1, HER2 and HER3 receptors was investigated by semi-quantitative immunohistochemistry. The association of their pattern of expression with survival was evaluated by Kaplan–Meier and Cox’s proportional hazard analyses. Multivariable Cox proportional hazards models were developed to predict median 2- and 3-year RFS and 2.5- and 5-year OS. The Akaike information criterion technique and backwards stepwise procedure were used for model selections. The performance of the final Cox models was assessed with respect to calibration and discrimination.

Results

Immunohistochemical labeling for HER1 and HER2 was localized both in the cell membrane and in the cytoplasm, while HER3 labeling was observed both in the cell cytoplasm and in the nucleus. HER3 expression was inversely correlated with HER1 positivity. The expression patterns of HERs were associated with tumor differentiation. In both cohorts of patients, HER1 expression was associated with reduced relapse-free (RFS) and overall survival (OS). In HER1 positive tumors, the co-expression with nuclear HER3 was associated with better RFS and OS, compared with HER3 negative tumors or tumors expressing HER3 at cytoplasmic level. HER3 expressing tumors had a higher Geminin/MCM7 ratio than HER3 negative ones, regardless of HER1 co-expression. Multivariable analyses identified age at diagnosis, tumor site, HER1, HER3 and age at diagnosis, tumor stage, HER1, HER3, as covariates significantly associated with RFS and OS, respectively. Bootstrapping verified the good fitness of these models for predicting survivals and the optimism-corrected C-indices were 0.76 and 0.77 for RFS and OS, respectively.

Conclusions

Nuclear HER3 expression was strongly associated with favourable prognosis and allows to improve the prognostic stratification of patients with HER1 positive advanced LSCC carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03081-0.

Molecular Marker as a Prognostic Indicator in Head and Neck Cancer Patients

Head and neck cancer forms the major burden of cancer in the developing countries. Despite advancement in the treatment approach of head and neck cancer in terms of surgery, chemotherapy and radiotherapy overall long-term survival remains low due to uncontrollable persistent and recurrent disease. This low survival rate has demanded for the need for newer treatment approaches and prognostic markers. In a previously published study "impact of molecular predictors on the response rates in head and neck Cancer patients" by Koushik et al. assessed the impact of molecular markers like HPV, P53, and EGFR status along with other prognostic factors like tobacco use, age, sex, and socioeconomic status on response to treatment of head and neck cancer patients. Our present study is intent to provide update of the impact of those molecular markers on survival. Objective of our study is to correlate the HPV, EGFR, and P53 status with the survival rate of the head and neck cancer patients. Twenty-five histologically proven head and neck cancer patients were assessed for HPV, EGFR, and P53 status who underwent chemoradiation to a dose of 66 Gy in 33 fraction along with weekly cisplatin of 40 mg/m², and all treated patients were followed up to a minimum of 3 years and analyzed for the survival. We found that 3-year survival for complete responders after treatment is 61.5% and partial responders, 57.1%; stable disease is 33.3%, and progressive disease is 0%. A 3-year survival for HPV-positive patients is 57.4% (p = 0.973), EGFR-mutated patients is 47.62% (p = 0.593), and P53-mutated patients is 57.89% (p = 0.378).

Expression of CD44, EGFR, p16, and their mutual combinations in patients with head and neck cancer: Impact on outcomes of intensity-modulated radiation therapy

BACKGROUND

Progress in radiation treatment of head and neck squamous cell carcinoma (HNSCC) deserves the studies focused on molecular predictors that would help to enhance individually tailored treatment.

METHODS

p16/epidermal growth factor receptor (EGFR)/cluster of differentiation-44 (CD44) was immunohistochemically analyzed in 165 HNSCC patients.

RESULTS

In the entire group and the p16 negative cohort, better 3-year overall survival and locoregional control correlated with p16 positivity, CD44, and EGFR negativity were observed. Combined analysis revealed the worst results in the CD44+/p16-, EGFR+/p16-, and EGFR+/CD44+ groups and in the EGFR+/CD44+ within p16 negative cohort. Multivariate analysis found tumor stage, Karnofsky index, p16, and CD44 as prognostic factors of overall survival and clinical stage, and p16 as a prognostic factor for locoregional control. Clinical stage and Karnofsky index affected overall survival and tumor stage. EGFR affected locoregional control in the p16 negative subgroup.

CONCLUSION

Our study confirmed the negative effect of CD44 and EGFR and the positive effect of p16 on radiotherapy results.

Developing Predictive or Prognostic Biomarkers for Charged Particle Radiotherapy

The response to radiotherapy can vary greatly among individuals, even though advances in technology allow for the highly localized placement of therapeutic doses of radiation to a tumor. This variability in patient response to radiation is biologically driven, but the individuality of tumor and healthy tissue biology are not used to create individual treatment plans. Biomarkers of radiosensitivity, whether intrinsic or from hypoxia, would move radiation oncology from precision medicine to precise, personalized medicine. Charged particle radiotherapy allows for even greater dose conformity, but the biological advantages of charged particle radiotherapy have not yet been cultivated. The development of biomarkers that would drive biologically based clinical trials, identify patients for whom charged particles are most appropriate, or aid in particle-selection strategies could be envisioned with appropriate biomarkers. Initially, biomarkers for low-linear energy transfer (LET) radiation responses should be tested against charged particles. Biomarkers of tumor radioresistance to low-LET radiations could be used to identify patients for whom the enhanced relative biological effectiveness (RBE) of charged particles would be more effective compared with low-LET radiations and those for whom specific DNA-repair inhibitors, in combination with charged particles, may also be appropriate. Furthermore, heavy charged particles can overcome the radioresistance of hypoxic tumors when used at the appropriate LET. Biomarkers for hypoxia could identify hypoxic tumors and, in combination with imaging, define hypoxic regions of a tumor for specific ion selection. Moreover, because of the enhanced RBE for charged particles, the risk for adverse healthy tissue effects may be greater, even though charged particles have greater tumor conformality. There are many validated healthy-tissue biomarkers available to test against charged particle exposures. Lastly, newer biological techniques, as well as newer bioinformatic and computational methods, are rapidly changing the landscape for biomarker identification, validation, and clinical trial design.

Genetics and management of locally advanced carcinomas of the head and neck: role of altered fractionation radiotherapy

Squamous cell carcinoma of the head and neck (SCCHN) accounts for 5-7% of all malignancies. About 60% of newly diagnosed SCCHN are detected as locally advanced disease. Chemoradiation is a standard option and response rate to it is variable. Recently, a genetic classification of SCCHN has been proposed by Chung et al., who categorized all SCCHN into four subtypes. The basal-like variant is characterized by high expression of EGFR. Literature data suggest higher efficacy of accelerated and/or hyperfractionated radiotherapy, if compared with conventional radiotherapy in the subgroup of patients with high EGFR expression. In this review, we will describe the genetic factors able to guide treatment choice, with a focus on EGFR expression.

Prognostic and predictive value of EGFR in head and neck squamous cell carcinoma

EGFR is an extensively studied biomarker in head and neck squamous cell carcinoma (HNSCC). In this review, we discuss the prognostic and predictive role of EGFR in HNSCC, focusing on the different molecular alterations in specific treatment modalities such as radiotherapy alone (RT), combination of surgery, RT and chemotherapy (CT), EGFR inhibitors. We considered EGFR at different molecular levels: protein expression, protein activation, gene copy number, polymorphisms, mutation, EGFRvIII expression and EGFR ligand expression.

Considering RT alone, evidence supports the predictive and prognostic role of high EGFR expression only when evaluated by quantitative assays: this may help select the patients who can mostly benefit from accelerated treatment. Conversely, no predictive biomarkers are available when treatment is a combination of surgery, CT and RT. For this combined treatment, several studies indicate that EGFR expression represents a good prognostic parameter only when measured by a “quantitative” or at least semi-quantitative method. With respect to EGFR inhibitors, neither EGFR expression nor increased gene copy number represent prognostic/predictive factors.

If validated, nuclear EGFR, TGFα levels, EGFR phopshorylation and polymorphisms could represent additional prognostic factors in relation to combination of surgery, CT and RT, while EGFR polymorphisms and high amphiregulin levels could have prognostic value in patients treated with EGFR inhibitors.

Molecularly-targeted therapy for the oral cancer stem cells

Human cancer tissues are heterogeneous in nature and become differentiated during expansion of cancer stem cells (CSCs). CSCs initiate tumorigenesis, and are involved in tumor recurrence and metastasis. Furthermore, data show that CSCs are highly resistant to anticancer drugs. Cetuximab, a specific anti-epidermal growth factor receptor (EGFR) monoclonal antibody, is used in cancer treatment. Although development of resistance to cetuximab is well recognized, the underlying mechanisms remain unclear. Lapatinib, a dual inhibitor of epidermal growth factor receptor (EGFR)/ErbB2, has antiproliferative effects and is used to treat patients with ErbB2-positive metastatic breast cancer. In this review, cetuximab and lapatinib-resistant oral squamous cell carcinoma (OSCC) cells proliferation and migration signal transduction passway is discussed by introducing our research.

Overview of Current Treatment Options and Investigational Targeted Therapies for Locally Advanced Squamous Cell Carcinoma of the Head and Neck

Patients with squamous cell carcinoma of the head and neck (SCCHN) typically present with locally advanced (LA) stage III or IV disease and are treated with combined-modality therapy with chemotherapy, radiotherapy, and surgery (if resectable). These aggressive, upfront treatment measures are often associated with substantial morbidity, and about half the patients develop locoregional or distant recurrences. Thus, new therapeutic strategies are needed that offer similar efficacy benefits with less toxicity. Current research is focused on selectively targeting signaling pathways involved in the proliferation and malignant transformation of SCCHN cells and the tumor microenvironment. For example, the ErbB receptor pathway has been implicated in the development and progression of SCCHN, and several agents targeting this pathway and downstream effectors are in various phases of clinical investigation. Cetuximab, a monoclonal antibody against epidermal growth factor receptor (EGFR), is the only currently approved targeted therapy for the treatment of LA SCCHN. Additional agents targeting EGFR and other ErbB family members, including monoclonal antibodies (eg, panitumumab, nimotuzumab) and small-molecule tyrosine kinase inhibitors (eg, erlotinib, afatinib, lapatinib) are being studied in LA SCCHN with varying results. Other treatment strategies for LA SCCHN include targeting downstream effectors of signaling and resistance mechanisms to EGFR inhibitors (eg, mammalian target of rapamycin, Src family, and Aurora kinase family). Data from ongoing and future clinical trials will continue to refine current treatment paradigms for LA SCCHN and provide new therapeutic options and potential predictive biomarkers to improve patient efficacy and safety and abrogate resistance.

Modified docetaxel, cisplatin and fluorouracil therapy as the first-line treatment for patients with recurrent/metastatic squamous cell carcinoma of the head and neck cancer: a retrospective study

AIM

Modified docetaxel, cisplatin, and 5-fluorouracil (mDCF) therapy has been shown to be a well tolerated and highly effective regimen for metastatic gastric carcinoma. Herein we investigated the effectiveness of the mDCF combination as the first-line treatment in patients with recurrent/metastatic squamous cell carcinoma of the head and neck (HNSCC).

METHODS

A total of 80 patients with recurrent/metastatic HNSCC who were treated with mDCF between 2009 and 2015 were enrolled into this study. All patients were treated in the first-line with 2-6 cycles of mDCF chemotherapy which consisted of docetaxel 60 mg/m² intravenously (IV) on day 1, cisplatin 60 mg/m² IV on day 1, and 5-fluorouracil 600 mg/m² IV for 5 days of continuous infusion, with cycles repeated every 21 days.

RESULTS

The most common grade 3-4 toxicities were neutropenia (22.5%), anemia (10%), thrombocytopenia (7.5%), nephrotoxicity (1.3%), hepatotoxicity (1.3%), and diarrhea (2.5%). Twelve patients (15%) experienced a febrile neutropenic episode. Dose modification was required in 22 (27.5%) of the patients due to drug toxicity. Complete response was achieved in 2.5% of all patients, while partial and stable responses were reported to be 43.8% and 25%, respectively, with a disease control rate of 71.3%. The median progression-free and overall survival was 7 (95% CI: 5.3-8.6) and 11.5 (95% CI: 9.4-13.7) months, respectively.

CONCLUSIONS

The efficiency of the mDCF combination for induction chemotherapy has been well established previously. To our knowledge, this is one of the largest studies evaluating the survival and safety significance of mDCF chemotherapy as a first-line treatment in patients with recurrent/metastatic HNSCC.

Targeting epidermal growth factor receptor for head and neck squamous cell carcinoma: still lost in translation?

The epidermal growth factor receptor (EGFR) is preferentially expressed in head and neck squamous cell carcinoma (HNSCC), and is a promising therapeutic target. Yet other than cetuximab, no agent targeting EGFR has been approved for this disease, and none has shown benefit over the standard of care. Several randomized trials of antibody and small molecule agents have found no new indication for these agents, despite their initial promise. In this review, we examine the major clinical evidence and discuss potential future developments of translational science in this area, including use of these agents in risk-stratified subgroups, inhibition of downstream/parallel targets, and combination with immunotherapy.

Systemic therapy for squamous cell carcinoma of the head and neck

The use of systemic therapy as part of curative treatment and palliation is an evolving paradigm for squamous cell cancer of the head and neck (SCCHN), which historically has been treated with local modalities. At present, the treatment armamentarium includes traditional cytotoxic therapy, targeted biological agents, and emerging immunotherapeutics. This article discusses the use of all of these systemic approaches for the curative and palliative treatment of SCCHN.

The STAT3 pathway as a therapeutic target in head and neck cancer: Barriers and innovations

Proteins of the signal transducer and activator of transcription (STAT) family mediate cellular responses to cytokines and growth factors. Aberrant regulation of the STAT3 oncogene contributes to tumor formation and progression in many cancers, including head and neck squamous cell carcinoma (HNSCC), where hyperactivation of STAT3 is implicated in both treatment resistance and immune escape. There are no oncogenic gain-of-function mutations in HNSCC. Rather, aberrant STAT3 signaling is primarily driven by upstream growth factor receptors, such as Janus kinase (JAK) and epidermal growth factor receptor (EGFR). Moreover, genomic silencing of select protein tyrosine phosphatase receptors (PTPRs), tumor suppressors that dephosphorylate STAT3, may lead to prolonged phosphorylation and activation of STAT3. This review will summarize current knowledge of the STAT3 pathway and its contribution to HNSCC growth, survival, and resistance to standard therapies, and discuss STAT3-targeting agents in various phases of clinical development.

Human Papillomavirus-Associated Oropharyngeal Cancer: Defining Risk Groups and Clinical Trials

Human papillomavirus-associated oropharynx cancer (HPVA-OPC) is rapidly increasing in incidence and has unique epidemiologic, molecular, and biologic characteristics. Despite being recognized as having superior prognosis, current evidence does not support less intense therapy compared with HPV-negative OPC. Current combined modality therapies confer a significant risk of morbidity, and patients with HPVA-OPC have a younger median age. These patients, therefore, live longer with the adverse effects of treatment, and this spurs the development of treatment deintensification trials that attempt to decrease treatment-related morbidity without compromising efficacy. Many radiation and chemotherapy de-escalation trials are underway. Minimally invasive surgical techniques are also being evaluated. It is important to identify the ideal patient group for treatment deintensification and to define prognostic risk groups to avoid undertreating the poorer-risk subset in HPVA-OPC, and validated biomarkers are needed to identify patients with the best prognosis. Significant smoking exposure mitigates the favorable prognosis of HPVA-OPC. Currently, less intense treatment is an option only in the setting of clinical trials, and patients with HPVA-OPC should be offered clinical trial options whenever they are available. Finally, recognition of novel therapeutic targets and signaling pathways is critical to the development of new treatment strategies that are desperately needed for patients with poor risk and those with recurrent and metastatic disease.

Effective Biomarkers and Radiation Treatment in Head and Neck Cancer

CONTEXT

Radiation is a key arm in the multidisciplinary treatment of patients with head and neck squamous cell carcinoma. During the past 2 decades, significant changes in the way radiation therapy is planned and delivered have improved efficacy and decreased toxicity. Refined approaches in the application of radiation and chemoradiation have led to organ-sparing treatment regimens for laryngeal and pharyngeal cancers and have improved local and regional control rates in the postoperative, adjuvant setting. The molecular and genetic determinants of tumor cell response to radiation have been studied, and several potential biomarkers are emerging that could further improve application and efficacy of radiation treatment in head and neck squamous cell carcinoma.

OBJECTIVE

To discuss the current understanding of potential biomarkers related to radiation response in head and neck squamous cell carcinoma.

DATA SOURCES

Existing published literature.

CONCLUSIONS

Several potential biomarkers are actively being studied as predictors and targets to improve the use and efficacy of radiation therapy to treat head and neck squamous cell carcinoma. Several promising candidates have been defined, and new markers are on the horizon.

Decreased SMAD4 expression is associated with induction of epithelial-to-mesenchymal transition and cetuximab resistance in head and neck squamous cell carcinoma

Epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and cetuximab, a monoclonal antibody targeting this receptor, is widely used to treat these patients. In the following investigation, we examined the role of SMAD4 down-regulation in mediating epithelial-to-mesenchymal transition (EMT) and cetuximab resistance in HNSCC. We determined that SMAD4 downregulation was significantly associated with increased cell motility, increased expression of vimentin, and cetuximab resistance in HNSCC cell lines. In the HNSCC genomic dataset obtained from The Cancer Genome Atlas, SMAD4 was altered in 20/279 (7%) of HNSCC via homozygous deletion, and nonsense, missense, and silent mutations. When SMAD4 expression was compared with respect to human papillomavirus (HPV) status, HPV-positive tumors had higher expression compared to HPV-negative tumors. Furthermore, higher SMAD4 expression also correlated with higher CDKN2A (p16) expression. Our data suggest that SMAD4 down-regulation plays an important role in the induction of EMT and cetuximab resistance. Patients with higher SMAD4 expression may benefit from cetuximab use in the clinic.

Designing biomarker studies for head and neck cancer

Although there is ample literature reporting on the identification of molecular biomarkers for head and neck squamous cell carcinoma, none is currently recommended for routine clinical use. A major reason for this lack of progress is the difficulty in designing studies in head and neck cancer to clearly establish the clinical utility of biomarkers. Consequently, biomarker studies frequently stall at the initial discovery phase. In this article, we focus on biomarkers for use in clinical management, including selection of therapy. Using several contemporary examples, we identify some of the common deficiencies in study design that hinder success in biomarker development for this disease area, and we suggest some potential solutions. The purpose of this article is to provide guidance that can assist investigators to more efficiently move promising biomarkers in head and neck cancer from discovery to clinical practice

Randomized phase III trial of concurrent accelerated radiation plus cisplatin with or without cetuximab for stage III to IV head and neck carcinoma: RTOG 0522

PURPOSE

Combining cisplatin or cetuximab with radiation improves overall survival (OS) of patients with stage III or IV head and neck carcinoma (HNC). Cetuximab plus platinum regimens also increase OS in metastatic HNC. The Radiation Therapy Oncology Group launched a phase III trial to test the hypothesis that adding cetuximab to the radiation-cisplatin platform improves progression-free survival (PFS).

PATIENTS AND METHODS

Eligible patients with stage III or IV HNC were randomly assigned to receive radiation and cisplatin without (arm A) or with (arm B) cetuximab. Acute and late reactions were scored using Common Terminology Criteria for Adverse Events (version 3). Outcomes were correlated with patient and tumor features and markers.

RESULTS

Of 891 analyzed patients, 630 were alive at analysis (median follow-up, 3.8 years). Cetuximab plus cisplatin-radiation, versus cisplatin-radiation alone, resulted in more frequent interruptions in radiation therapy (26.9% v. 15.1%, respectively); similar cisplatin delivery (mean, 185.7 mg/m2 v. 191.1 mg/m2, respectively); and more grade 3 to 4 radiation mucositis (43.2% v. 33.3%, respectively), rash, fatigue, anorexia, and hypokalemia, but not more late toxicity. No differences were found between arms A and B in 30-day mortality (1.8% v. 2.0%, respectively; P = .81), 3-year PFS (61.2% v. 58.9%, respectively; P = .76), 3-year OS (72.9% v. 75.8%, respectively; P = .32), locoregional failure (19.9% v. 25.9%, respectively; P = .97), or distant metastasis (13.0% v. 9.7%, respectively; P = .08). Patients with p16-positive oropharyngeal carcinoma (OPC), compared with patients with p16-negative OPC, had better 3-year probability of PFS (72.8% v. 49.2%, respectively; P < .001) and OS (85.6% v. 60.1%, respectively; P < .001), but tumor epidermal growth factor receptor (EGFR) expression did not distinguish outcome.

CONCLUSION

Adding cetuximab to radiation-cisplatin did not improve outcome and hence should not be prescribed routinely. PFS and OS were higher in patients with p16-positive OPC, but outcomes did not differ by EGFR expression.

A randomized phase II efficacy and correlative studies of cetuximab with or without sorafenib in recurrent and/or metastatic head and neck squamous cell carcinoma

INTRODUCTION

A combination of cetuximab and sorafenib in patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) were assessed for potential benefit.

MATERIAL AND METHODS

In a randomized phase II study, R/M HNSCC patients were treated with cetuximab 400mg/m(2) IV on day 1 followed by 250mg/m(2) IV weekly (Arm A), or cetuximab at the same dose/schedule plus sorafenib 400mg PO twice-a-day (Arm B). Each cycle was 21days. Tumor p16 and HPV status, and plasma immunomodulatory cytokine levels were assessed.

RESULTS

Of 55 patients enrolled (Arm A-27, Arm B-28), 52 patients received assigned treatments and 43 were evaluable for response. Overall response rate was 8% for both arms. Median overall survival (OS) and progression-free survival (PFS) were 9.0 and 3.0months in Arm A, and 5.7 and 3.2months in Arm B, respectively. Forty-four patients had tumors available for p16 staining (35-negative, 9-positive). Three of nine p16-positive tumors were also HPV positive. The p16-negative patients had significantly better PFS compared to the p16-positive patients (3.7 vs. 1.6months; p-value: 0.03), regardless of study arms. Twenty-four plasma samples were tested for 12 cytokine levels and patients with higher TGFβ1 levels had inferior PFS compared to lower levels (1.9 vs. 4.7months; adjusted p-value: 0.015), regardless of study arms.

CONCLUSIONS

A subset of R/M patients with p16-negative tumors or lower plasma TGFβ1 levels had longer PFS given the cetuximab-based therapy. However, both arms showed only modest response and sorafenib given with cetuximab did not demonstrate clinical benefit.

Keratin 5 expression in squamocellular carcinoma of the head and neck

Keratin 5 (K5) is present in the basal layer of a stratified squamous keratinized and non-keratinized epithelium. K5 and K14 have been demonstrated in the mucosa and tumors of the oral cavity, oropharynx, hypopharynx and larynx, and in the mitotic active basal cells of a stratified squamous epithelium. The aim of the present study was to assess K5 expression in squamocellular carcinoma with various localizations in the head and neck. A total of 13 biopsy fragments were included from patients diagnosed with squamocellular carcinoma of the larynx area (n=2), pharynx (n=2), hard palate (n=1), tongue (n=2), submandibular (n=1), lip (n=1), gingival sulcus (n=1), nasal pyramid (n=1), maxilla (n=1) and zygomatic (n=1). The immunohistochemical staining for K5 was evaluated according to the following score criteria: 0 (0% positive cells); 1 (<10% positive cells); 2 (10-30% positive cells); and 3 (>30% positive cells). K5 expression was observed in all squamocellular carcinomas included in the present study with scores between 1 and 3. For well- and moderately-differentiated histopathological types, a maximum score of 3 was recorded for all of the cases, not including the laryngeal area, which presented a score of 2. The following scores were identified in the regions of the poorly differentiated carcinomas: Jaw, 3; gingival sulcus, 2; and tongue and submandibular area, 1. These observations may aid with an improved stratification of head and neck squamocellular carcinoma, thus improving the diagnosis and treatment strategies for this type of cancer.

Randomized phase III trial of concurrent accelerated radiation plus cisplatin with or without cetuximab for stage III to IV head and neck carcinoma: RTOG 0522

PURPOSE

Combining cisplatin or cetuximab with radiation improves overall survival (OS) of patients with stage III or IV head and neck carcinoma (HNC). Cetuximab plus platinum regimens also increase OS in metastatic HNC. The Radiation Therapy Oncology Group launched a phase III trial to test the hypothesis that adding cetuximab to the radiation-cisplatin platform improves progression-free survival (PFS).

PATIENTS AND METHODS

Eligible patients with stage III or IV HNC were randomly assigned to receive radiation and cisplatin without (arm A) or with (arm B) cetuximab. Acute and late reactions were scored using Common Terminology Criteria for Adverse Events (version 3). Outcomes were correlated with patient and tumor features and markers.

RESULTS

Of 891 analyzed patients, 630 were alive at analysis (median follow-up, 3.8 years). Cetuximab plus cisplatin-radiation, versus cisplatin-radiation alone, resulted in more frequent interruptions in radiation therapy (26.9% v. 15.1%, respectively); similar cisplatin delivery (mean, 185.7 mg/m2 v. 191.1 mg/m2, respectively); and more grade 3 to 4 radiation mucositis (43.2% v. 33.3%, respectively), rash, fatigue, anorexia, and hypokalemia, but not more late toxicity. No differences were found between arms A and B in 30-day mortality (1.8% v. 2.0%, respectively; P = .81), 3-year PFS (61.2% v. 58.9%, respectively; P = .76), 3-year OS (72.9% v. 75.8%, respectively; P = .32), locoregional failure (19.9% v. 25.9%, respectively; P = .97), or distant metastasis (13.0% v. 9.7%, respectively; P = .08). Patients with p16-positive oropharyngeal carcinoma (OPC), compared with patients with p16-negative OPC, had better 3-year probability of PFS (72.8% v. 49.2%, respectively; P < .001) and OS (85.6% v. 60.1%, respectively; P < .001), but tumor epidermal growth factor receptor (EGFR) expression did not distinguish outcome.

CONCLUSION

Adding cetuximab to radiation-cisplatin did not improve outcome and hence should not be prescribed routinely. PFS and OS were higher in patients with p16-positive OPC, but outcomes did not differ by EGFR expression.

Resistance of oral squamous cell carcinoma cells to cetuximab is associated with EGFR insensitivity and enhanced stem cell-like potency

Cetuximab, a specific anti-epidermal growth factor receptor (EGFR) monoclonal antibody, is used in cancer treatment. Although development of resistance to cetuximab is well recognized, the underlying mechanisms remain unclear. In the present study, we characterized cetuximab-resistant oral squamous cell carcinoma (OSCC) cell lines. The human OSCC cell lines HSC3, HSC4 and SAS were used in the present study. Effects of inhibitors including cetuximab on growth in cells were assessed by MTT assays. Southern blotting and immunofluorescence analysis were performed to examine protein expression and localization. Sphere formation was used to characterize stem cell-like properties. Floating aggregation culture was used for anchorage-independent growth. Cetuximab inhibited proliferation of HSC3 and HSC4 cells, but not SAS cells. Proliferation of all three cell lines was inhibited by the EGFR/ErbB2/ErbB4 inhibitor II. The EGFR inhibitor AG1478 strongly inhibited HSC3 and HSC4 proliferation, but that of SAS cells only moderately. EGFR proteins were localized on cell surface and phosphorylated in all three cell lines. SAS cells could proliferate in serum-free monolayer culture and formed spheres from single cells in floating culture. HSC3 and HSC4 could not proliferate under serum-free culture conditions and could not form spheres. Growth of SAS spheres required serum, and was inhibited by both AG1478 and cetuximab. Thus, cetuximab-resistant SAS cells not only engaged in EGFR-independent growth but also exhibited stem cell-like properties. However, growth was EGFR-dependent in aggregation culture, and the SAS cell aggregates became cetuximab-sensitive. This suggests that cetuximab sensitivity is not only cell-type-dependent but is also affected by the growth microenvironment.

Low PTEN expression is associated with worse overall survival in head and neck squamous cell carcinoma patients treated with chemotherapy and cetuximab

BACKGROUND

Platinum-based chemotherapy associated with cetuximab is the first-line treatment for inoperable recurrence or metastatic head and neck squamous cell carcinoma (HNSCC). There is no established biomarker for cetuximab efficacy in HNSCC. The PI3K pathway is one of the most frequently altered pathways in HNSCC. Loss of phosphatase and tensin homolog (PTEN) expression occurs in up to 30 % of cases.

METHODS

This was a retrospective analysis of data from 61 patients with inoperable recurrence or metastatic HNSCC treated with cetuximab. PTEN, epidermal growth factor receptor and p16 expression were analyzed by immunohistochemistry and tested for association with clinical outcomes.

RESULTS

Median overall survival was 11.4 months and progression-free survival was 6.9 months. Low PTEN expression was present in 26.2 % of patients and identified patients with worse prognosis. p16 was positive in only 8.5 % of tumors.

CONCLUSIONS

Low PTEN expression in patients treated with cetuximab plus chemotherapy emerged as a prognostic biomarker and should be evaluated for its predictive role for cetuximab efficacy.

De-escalation treatment protocols for human papillomavirus-associated oropharyngeal squamous cell carcinoma

BACKGROUND

Human papillomavirus-associated oropharyngeal squamous cell carcinomas are a distinct subgroup of tumours that may have a better prognosis than traditional tobacco/alcohol-related disease. Iatrogenic complications, associated with conventional practice, are estimated to cause mortality of approximately 2% and high morbidity. As a result, clinicians are actively investigating the de-escalation of treatment protocols for disease with a proven viral aetiology.

OBJECTIVES

To summarise the available evidence regarding de-escalation treatment protocols for human papillomavirus-associated, locally advanced oropharyngeal squamous cell carcinoma.

SEARCH METHODS

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 25 June 2013.

SELECTION CRITERIA

Randomised controlled trials investigating de-escalation treatment protocols for human papillomavirus-associated, locally advanced oropharyngeal carcinoma. Specific de-escalation categories were: 1) bioradiotherapy (experimental) versus chemoradiotherapy (control); 2) radiotherapy (experimental) versus chemoradiotherapy (control); and 3) low-dose (experimental) versus standard-dose radiotherapy (control). The outcomes of interest were overall and disease-specific survival, treatment-related morbidity, quality of life and cost.

DATA COLLECTION AND ANALYSIS

Three authors independently selected studies from the search results and extracted data. We planned to use the Cochrane 'Risk of bias' tool to assess study quality.

MAIN RESULTS

We did not identify any completed randomised controlled trials that could be included in the current version of this systematic review. We did, however, identify seven ongoing trials that will meet our inclusion criteria. These studies will report from 2014 onwards. We excluded 30 studies on methodological grounds (seven randomised trials with post hoc analysis by human papillomavirus status, 11 prospective trials and 12 ongoing studies).

AUTHORS' CONCLUSIONS

There is currently insufficient high-quality evidence for, or against, de-escalation of treatment for human papillomavirus-associated oropharyngeal carcinoma. Future trials should be multicentre to ensure adequate power. Adverse events, morbidity associated with treatment, quality of life outcomes and cost analyses should be reported in a standard format to facilitate comparison with other studies.

Genetic alterations in head and neck squamous cell carcinoma: The next-gen sequencing era

Head and neck squamous cell carcinoma is the sixth most common cancer in the world with approximately 650000 new cases diagnosed annually. Next-generation molecular techniques and results from phase 2 of the Cancer Genome Atlas becoming available have drastically improved our current knowledge on the genetics basis of head and neck squamous cell carcinoma. New insights and new perspectives on the mutational landscape implicated in head and neck squamous cell carcinoma provide improved tools for prognostication. More importantly, depend on the patient’s tumor subtypes and prognosis, deescalated or more aggressive therapy maybe chosen to achieve greater potency while minimizing the toxicity of therapy. This paper aims to review our current knowledge on the genetic mutations and altered molecular pathways in head and neck squamous cell carcinoma. Some of the most common mutations in head and neck squamous cell carcinoma reported by the cancer genome atlas including TP53, NOTCH1, Rb, CDKN2A, Ras, PIK3CA and EGFR are described here. Additionally, the emerging role of epigenetics and the role of human papilloma virus in head and neck squamous cell carcinoma are also discussed in this review. The molecular pathways, clinical applications, actionable molecular targets and potential therapeutic strategies are highlighted and discussed in details.

Silencing Met receptor tyrosine kinase signaling decreased oral tumor growth and increased survival of nude mice

OBJECTIVES

The hepatocyte growth factor receptor (Met) is frequently overexpressed in Head and Neck Squamous Cell Carcinoma (HNSCC), correlating positively with high-grade tumors and shortened patient survival. As such, Met may represent an important therapeutic target. The purpose of this study was to explore the role of Met signaling for HNSCC growth and locoregional dissemination.

MATERIALS AND METHODS

Using a lentiviral system for RNA interference, we knocked down Met in established HNSCC cell lines that express high levels of the endogenous receptor. The effect of Met silencing on in vitro proliferation, cell survival and migration was examined using western analysis, immunohistochemistry and live cell imaging. In vivo tumor growth, dissemination and mouse survival was assessed using an orthotopic tongue mouse model for HNSCC.

RESULTS

We show that Met knockdown (1) impaired activation of downstream MAPK signaling; (2) reduced cell viability and anchorage independent growth; (3) abrogated HGF-induced cell motility on laminin; (4) reduced in vivo tumor growth by increased cell apoptosis; (5) caused reduced incidence of tumor dissemination to regional lymph nodes and (6) increased the survival of nude mice with orthotopic xenografts.

CONCLUSION

Met signaling is important for HNSCC growth and locoregional dissemination in vivo and that targeting Met may be an important strategy for therapy.

CT imaging correlates of genomic expression for oral cavity squamous cell carcinoma

BACKGROUND AND PURPOSE

Imaging correlates of genetic expression have been found for prognostic and predictive biomarkers of some malignant diseases, including breast and brain tumors. This study tests the hypothesis that imaging findings correlate with relevant genomic biomarkers in oral cavity squamous cell carcinoma.

MATERIALS AND METHODS

Surplus frozen tissue from 27 untreated patients with oral cavity squamous cell carcinoma who underwent preoperative CT imaging was analyzed for gene expression. A team of neuroradiologists blinded to the genomic analysis results reviewed an extensive list of CT findings. The imaging correlated with genomic expression for cyclin D1, angiogenesis-related genes (vascular endothelial growth factor receptors and ligands), which relate to enhancement on the basis of other tumor types; and epidermal growth factor receptor, which may relate to proliferation and mass effect.

RESULTS

Expression of vascular endothelial growth factor receptors 1 and 2 correlated with the enhancement of the primary tumor (P = .018 and P = .025, respectively), whereas the epidermal growth factor receptor correlated with mass effect (P = .03). Other exploratory correlations included epidermal growth factor receptor to perineural invasion (P = .05), and certain vascular endothelial growth factor receptors and ligands to mass effect (P = .03) and increased (P = .01) or decreased (P = .02) primary tumor size.

CONCLUSIONS

We report that CT imaging correlates with gene expression in untreated oral cavity squamous cell carcinoma. Enhancement of the primary tumor and degree of mass effect correlate with relevant genomic biomarkers, which are also potential drug targets. Eventually, treatment decisions may be aided by combining imaging findings into meaningful phenotypes that relate directly to genomic biomarkers.

Current role of EGF receptor monoclonal antibodies and tyrosine kinase inhibitors in the management of head and neck squamous cell carcinoma

New agents and treatment strategies that can be safely and effectively integrated into current treatment paradigms for head and neck squamous cell carcinoma (HNSCC) are urgently needed. To date, the anti-EGF receptor (EGFR) monoclonal antibody, cetuximab, is the first and only molecularly targeted therapy to demonstrate a survival benefit for patients with recurrent or metastatic disease. Other anti-EGFR-targeted therapies, including monoclonal antibodies (e.g., panitumumab and zalutumumab) and reversible and irreversible ErbB family tyrosine kinase inhibitors (e.g., lapatinib, afatinib and dacomitinib) are being actively investigated in Phase II and Phase III clinical trials. In addition, validated biomarkers are needed to predict clinical benefit and resistance to anti-EGFR therapy in HNSCC. This review will compare and contrast the mechanisms of action of anti-EGFR monoclonal antibodies and tyrosine kinase inhibitors and also discuss their role in the management of HNSCC and the potential impact of human papillomavirus status in the development of these targeted agents.

Nuclear epidermal growth factor receptor and p16 expression in head and neck squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Epidermal growth factor receptor (EGFR) and p16 (a surrogate marker of human papillomavirus [HPV] infection) expression are strong prognostic factors in patients with head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

We examined expression levels of total and nuclear EGFR as well as p16 status based on evidence that nuclear EGFR may have a role in DNA damage repair.

METHODS

An HPV-negative (SQ20B) and an HPV-positive (UMSCC47) HNSCC cell line were examined for EGFR and γH2AX expression. A tissue microarray containing 123 cores obtained from 101 HNSCC tumors was analyzed for EGFR expression by automated quantitative analysis and p16 expression by immunohistochemical staining, and these results were correlated with available clinical data.

RESULTS

SQ20B had higher EGFR expression than UMSCC47. Nuclear localization of EGFR on activation with transforming growth factor-α was observed in SQ20B, but not in UMSCC47. SQ20B also had increased γH2AX foci compared to UMSCC47, suggesting that SQ20B has more DNA damage compared to UMSCC47. Total and nuclear EGFR was reliably obtained from 80 of 101 patients. p16 levels were determined in 87 of 101 patients. p16 levels were strongly associated with the oropharyngeal subsite and poorly differentiated histology. Expression of total and nuclear EGFR was higher in p16-negative tumors compared to p16-positive tumors (Wilcoxon rank test, P = .038 and P = .014, respectively).

CONCLUSIONS

Further studies are required to determine a mechanistic link between these two prognostic factors and the significance of EGFR localization to nucleus in DNA damage repair pathway activation.

Correlation between EGFr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

Purpose

To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (T_D) during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT) is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC).

Methods

A survey of the published papers comparing 3-years of local regional control rate (LCR) for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of T_D were obtained by a model incorporating the overall time corrected biologically effective dose (BED) and a 3-year clinical LCR for high and low EGFr groups of patients (H_EGFr and L_EGFr), respectively. By obtaining the T_D from the above analysis and the sub-sites’ potential doubling time (T_pot) from flow cytometry and immunohistochemical methods, we were able to estimate the average T_D for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (D_prolif), was estimated.

Results

The averages of T_D were 77 (27-90)_95% days in L_EGFr and 8.8 (7.3-11.0)_95% days in H_EGFr, if an onset of accelerated proliferation T_K at day 21 was assumed. The correspondent H_EGFr sub-sites’ T_D were 5.9 (6.6), 5.9 (6.6), 4.6 (6.1), 14.3 (12.9) days, with respect to literature immunohistochemical (flow cytometry) data of T_pot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The D_prolif for the H_EGFr groups were 0.33 (0.29), 0.33 (0.29), 0.42 (0.31), 0.14 (0.15) Gy/day if α = 0.3 Gy^-1 and α/β = 10 Gy were assumed.

Conclusions

A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced T_D and D_prolif for each head and neck sub-site.

New promising molecular targets in head and neck squamous cell carcinoma

PURPOSE OF REVIEW

Despite advances in multimodality therapy, the overall 5-year survival rate is 40-50% in patients with head and neck squamous cell carcinoma (HNSCC) and current multimodality approaches impart significant toxicities. This review highlights promising targets with the potential to improve clinical outcomes in HNSCC.

RECENT FINDINGS

In addition to mutagenic exposure to tobacco and alcohol as risk factors, recent studies have shown that human papillomavirus is one of the main causes of HNSCC and as such is being investigated as a therapeutic target. Furthermore, recent data generated from whole exome sequencing of HNSCC, new insights into the biology of DNA damage repair, and increased understanding of tumor hypoxia responses are pointing to new therapeutic possibilities for treating HNSCC.

SUMMARY

HNSCC is a heterogeneous disease. Improved treatment will require a rapid translation of basic science research, and the simultaneous development of novel therapeutics and corresponding biomarkers to guide their application.

Modelling the correlation between EGFr expression and tumour cell radiosensitivity, and combined treatments of radiation and monoclonal antibody EGFr inhibitors

Purpose

To estimate the effects of heterogeneity on tumour cell sensitivity to radiotherapy combined with radiosensitizing agents attributable to differences in expression levels of Epidermal Growth Factor Receptor (EGFr).

Materials and methods

Differences in radiosensitivity are not limited to cells of different cancer histotypes but also occur within the same cancer, or appear during radiotherapy if radiosensitizing drugs are combined with ionizing radiation. A modified biologically effective dose (MBED), has been introduced to account for changes in radiosensitivity parameters (α and α/β) rather than changes in dose/fraction or total dose as normally done with standard biologically effective dose (BED). The MBED approach was applied to cases of EGFr over-expression and cases where EGFr inhibitors were combined with radiation. Representative examples in clinical practice were considered.

Results

Assuming membrane EGFr over-expression corresponds to reduced radiosensitivity (α_H = 0.15 Gy^-1 and α_H/β_H = 7.5 Gy) relative to normal radiosensitivity (α = 0.2 Gy^-1 and α/β = 10 Gy), an increased dose per fraction of 2.42 Gy was obtained through the application of MBED, which is equivalent to the effect of a reference schedule with 30 fractions of 2 Gy. An equivalent hypo-fractionated regime with a dose per fraction of 2.80 Gy is obtained if 25 fractions are set. Dose fractionations modulated according to drug pharmacokinetics are estimated for combined treatments with biological drugs. Soft and strong modulated equivalent hypo-fractionations result from subtraction of 5 or 10 fractions, respectively.

Conclusions

During this computational study, a new radiobiological tool has been introduced. The MBED allows the required dose per fraction to be estimated when tumour radiosensitivity is reduced because EGFr is over-expressed. If radiotherapy treatment is combined with EGFr inhibitors, MBED suggests new treatment strategies, with schedules modulated according to drug pharmacokinetics.

Targeting FAK radiosensitizes 3-dimensional grown human HNSCC cells through reduced Akt1 and MEK1/2 signaling

PURPOSE

Focal adhesion kinase (FAK), a main regulator of integrin signaling and cell migration, is frequently overexpressed and hyperphosphorylated in human head-and-neck squamous cell carcinoma (HNSCC). We have previously shown that pharmacologic FAK inhibition leads to radiosensitization of 3-dimensionally grown HNSCC cell lines. To further evaluate the role of FAK in radioresistance and as a potential cancer target, we examined FAK and FAK downstream signaling in HNSCC cell lines grown in more physiologic extracellular matrix-based 3-dimensional cell cultures.

METHODS AND MATERIALS

Seven HNSCC cell lines were grown in 3-dimensional extracellular matrix and the clonogenic radiation survival, expression, and phosphorylation of FAK, paxillin, Akt1, extracellular signal-regulated kinase (ERK)1/2, and MEK1/2 were analyzed after siRNA-mediated knockdown of FAK, Akt1, MEK1, FAK+Akt1, or FAK+MEK1 compared with controls or stable overexpression of FAK. The role of MEK1/2 for clonogenic survival and signaling was investigated using the MEK inhibitor U0126 with or without irradiation.

RESULTS

FAK knockdown moderately or significantly enhanced the cellular radiosensitivity of 3-dimensionally grown HNSCC cells. The FAK downstream targets paxillin, Akt1, and ERK1/2 were substantially dephosphorylated under FAK depletion. FAK overexpression, in contrast, increased radiation survival and paxillin, Akt1, and ERK1/2 phosphorylation. The degree of radiosensitization upon Akt1, ERK1/2, or MEK1 depletion or U0126 was superimposable to FAK knockdown. Combination knockdown conditions (ie, Akt1/FAK, MEK1/FAK, or U0126/FAK) failed to provide additional radiosensitization.

CONCLUSIONS

Our data provide further evidence for FAK as important determinant of radiation survival, which acts in the same signaling axis as Akt1 and ERK1/2. These data strongly support our hypothesis that FAK is a relevant molecular target for HNSCC radiotherapy.

The anti-EGFR antibody cetuximab sensitizes human head and neck squamous cell carcinoma cells to radiation in part through inhibiting radiation-induced upregulation of HIF-1α

In this study, we investigated the mechanisms underlying cetuximab-mediated radiosensitization of HNSCC. Irradiation of HNSCC cells upregulated hypoxia-inducible factor-1 alpha (HIF-1α) via a mechanism involving de novo synthesis of HIF-1α protein. Radiation-induced upregulation of HIF-1α was completely abolished by concurrent treatment of HNSCC cells with cetuximab. Experimental elevation of constitutively expressed HIF-1α abolished cetuximab-mediated radiosensitization in HNSCC cells, whereas downregulation of HIF-1α by siRNA or a small molecule inhibitor enhanced responses of cetuximab-resistant HNSCC cells to cetuximab plus radiation. Our data suggest that cetuximab sensitizes cancer cells to ionizing radiation in part through inhibition of radiation-induced upregulation of HIF-1α.

Molecular markers for cancer prognosis and treatment: have we struck gold?

The last decade has witnessed an emerging role for molecular or biochemical markers indicating a specific cellular mechanism or tissue function, often called 'biomarkers'. Biomarkers such as altered DNA, proteins and inflammatory cytokines are critical in cancer research and strategizing treatment in the clinic. In this review we look at the application of biological indicators to cancer research and highlight their roles in cancer detection and treatment. With technological advances in gene expression, genomic and proteomic analysis, biomarker discovery is expanding fast. We focus on some of the predominantly used markers in different types of malignancies, their advantages, and their limitations. Finally we conclude by looking at the future of biomarkers, their utility in the tumorigenic studies, and the progress towards personalized treatment strategies.

Current management of advanced resectable oral cavity squamous cell carcinoma

The oral cavity is the most common site of head and neck squamous cell carcinoma, a disease which results in significant morbidity and mortality worldwide. Though the primary modality of treatment for patients with oral cavity cancer remains surgical resection, many patients present with advanced disease and are thus treated using a multi-disciplinary approach. Patients with extracapsular spread of lymphatic metastasis and surgical margins that remain positive have been found to be at high risk for local-regional recurrence and death from disease, and are most often recommended to receive both post-operative radiation as well as systemic chemotherapy. The basis for this approach, as well as scientific developments that underly future trials of novels treatments for patients with high-risk oral cavity cancer are reviewed.

Glioma-associated oncogene family zinc finger 1 expression and metastasis in patients with head and neck squamous cell carcinoma treated with radiation therapy (RTOG 9003)

PURPOSE

Glioma-associated oncogene family zinc finger 1 (GLI1) expression was assessed to determine a potential role of hedgehog (Hh) signaling in head and neck squamous cell carcinoma (HNSCC). Additional proteins known to be modulated by Hh signaling, including beta-catenin (CTNNB1) and epidermal growth factor receptor (EGFR), were also assessed to determine the correlation among these distinct signaling pathways.

PATIENTS AND METHODS

Nuclear GLI1 and CTNNB1 expression levels were determined in tumors from patients enrolled on Radiation Therapy Oncology Group (RTOG) 9003, a radiation fractionation trial. The results were also correlated with previously determined EGFR expression. The expression levels were evaluated in relation to three end points: time to metastasis (TTM), time to disease progression (TDP), and overall survival (OS).

RESULTS

Among 1,068 eligible patients, data on GLI1, CTNNB1, and EGFR were available in 339, 164, and 300 patients, respectively. Although CTNNB1 expression did not differentiate prognosis, GLI1 was associated with poorer outcomes, adjusted for age, TNM stages, and Karnofsky performance score, and the significant influence persisted in a multivariable analysis (quartile 4 [Q4] v Q1 to Q3: TTM hazard ratio [HR], 2.7; 95% CI, 1.5 to 4.9; TDP HR, 1.6; 95% CI, 1.1 to 2.5; OS HR, 1.9; 95% CI, 1.4 to 2.7). The significance of GLI1 persisted in a multivariable analysis that included EGFR expression levels.

CONCLUSION

These data suggest that Hh signaling may play an important role in metastasis and that GLI1 could serve as a marker in HNSCC, but the regulatory mechanisms and oncogenic significance need further investigation. Risk classification based on this analysis needs a validation in independent cohorts.