Predictive value of epidermal growth factor receptor expression for first-line chemotherapy plus cetuximab in patients with head and neck and colorectal cancer: analysis of data from the EXTREME and CRYSTAL studies

Simultaneous targeting of EGFR, HER2, and HER4 by afatinib overcomes intrinsic and acquired cetuximab resistance in head and neck squamous cell carcinoma cell lines

The epidermal growth factor receptor (EGFR, HER1) is a therapeutic target in head and neck squamous cell carcinoma (HNSCC). After initial promising results with EGFR-targeted therapies such as cetuximab, therapeutic resistance has become a major clinical problem, and new treatment options are therefore necessary. Moreover, the relationship between HER receptors, anti-EGFR therapies, and the human papillomavirus (HPV) status in HNSCC is not fully understood. In contrast to first-generation EGFR inhibitors, afatinib irreversibly inhibits multiple HER receptors simultaneously. Therefore, treatment with afatinib might result in a more pronounced therapeutic benefit, even in patients experiencing cetuximab resistance. In this study, the cytotoxic effect of afatinib as single agent and in combination with cisplatin was investigated in cetuximab-sensitive, intrinsically cetuximab-resistant, and acquired cetuximab-resistant HNSCC cell lines with different HPV status under normoxia and hypoxia. Furthermore, the influence of cetuximab resistance, HPV, and hypoxia on the expression of HER receptors was investigated. Our results demonstrated that afatinib was able to establish cytotoxicity in cetuximab-sensitive, intrinsically cetuximab-resistant, and acquired cetuximab-resistant HNSCC cell lines, independent of the HPV status. However, cross-resistance between cetuximab and afatinib might be possible. Treatment with afatinib caused a G₀ /G₁ cell cycle arrest as well as induction of apoptotic cell death. Additive to antagonistic interactions between afatinib and cisplatin could be observed. Neither cetuximab resistance nor HPV status significantly influenced the expression of HER receptors in HNSCC cell lines. In contrast, the expression of EGFR, HER2, and HER3 was significantly altered under hypoxia. Oxygen deficiency is a common characteristic of HNSCC tumors, and these hypoxic tumor regions often contain cells that are more resistant to treatment. However, we observed that afatinib maintained its cytotoxic effect under hypoxia. In conclusion, our preclinical data support the hypothesis that afatinib might be a promising therapeutic strategy to treat patients with HNSCC experiencing intrinsic or acquired cetuximab resistance.

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.

EGFR Trafficking in Physiology and Cancer

Signaling from the epidermal growth factor receptor (EGFR) elicits multiple biological responses, including cell proliferation, migration, and survival. Receptor endocytosis and trafficking are critical physiological processes that control the strength, duration, diversification, and spatial restriction of EGFR signaling through multiple mechanisms, which we review in this chapter. These mechanisms include: (i) regulation of receptor density and activation at the cell surface; (ii) concentration of receptors into distinct nascent endocytic structures; (iii) commitment of the receptor to different endocytic routes; (iv) endosomal sorting and postendocytic trafficking of the receptor through distinct pathways, and (v) recycling to restricted regions of the cell surface. We also highlight how communication between organelles controls EGFR activity along the endocytic route. Finally, we illustrate how abnormal trafficking of EGFR oncogenic mutants, as well as alterations of the endocytic machinery, contributes to aberrant EGFR signaling in cancer.

Emerging functions of the EGFR in cancer

The physiological function of the epidermal growth factor receptor (EGFR) is to regulate epithelial tissue development and homeostasis. In pathological settings, mostly in lung and breast cancer and in glioblastoma, the EGFR is a driver of tumorigenesis. Inappropriate activation of the EGFR in cancer mainly results from amplification and point mutations at the genomic locus, but transcriptional upregulation or ligand overproduction due to autocrine/paracrine mechanisms has also been described. Moreover, the EGFR is increasingly recognized as a biomarker of resistance in tumors, as its amplification or secondary mutations have been found to arise under drug pressure. This evidence, in addition to the prominent function that this receptor plays in normal epithelia, has prompted intense investigations into the role of the EGFR both at physiological and at pathological level. Despite the large body of knowledge obtained over the last two decades, previously unrecognized (herein defined as 'noncanonical') functions of the EGFR are currently emerging. Here, we will initially review the canonical ligand-induced EGFR signaling pathway, with particular emphasis to its regulation by endocytosis and subversion in human tumors. We will then focus on the most recent advances in uncovering noncanonical EGFR functions in stress-induced trafficking, autophagy, and energy metabolism, with a perspective on future therapeutic applications.

Are Fusion Transcripts in Relapsed/Metastatic Head and Neck Cancer Patients Predictive of Response to Anti-EGFR Therapies?

Prediction of benefit from combined chemotherapy and the antiepidermal growth factor receptor cetuximab is a not yet solved question in head and neck squamous cell carcinoma (HNSCC). In a selected series of 14 long progression-free survival (PFS) and 26 short PFS patients by whole gene and microRNA expression analysis, we developed a model potentially predictive of cetuximab sensitivity. To better decipher the “omics” profile of our patients, we detected transcript fusions by RNA-seq through a Pan-Cancer panel targeting 1385 cancer genes. Twenty-seven different fusion transcripts, involving mRNA and long noncoding RNA (lncRNA), were identified. The majority of fusions (81%) were intrachromosomal, and 24 patients (60%) harbor at least one of them. The presence/absence of fusions and the presence of more than one fusion were not related to outcome, while the lncRNA-containing fusions resulted enriched in long PFS patients (P = 0.0027). The CD274-PDCD1LG2 fusion was present in 7/14 short PFS patients harboring fusions and was absent in long PFS patients (P = 0.0188). Among the short PFS patients, those harboring this fusion had the worst outcome (P = 0.0172) and increased K-RAS activation (P = 0.00147). The associations between HNSCC patient's outcome following cetuximab treatment and lncRNA-containing fusions or the CD274-PDCD1LG2 fusion deserve validation in prospective clinical trials.

Expression of P-EGFR and P-Akt protein in esophageal squamous cell carcinoma and its prognosis

The phosphorylated epidermal growth factor receptor (P-EGFR) and phosphorylated Akt (P-Akt) protein in esophageal squamous cell carcinoma (ESCC) were studied, and its significance in clinical prognosis of patients was assessed. The expression of P-EGFR and P-Akt protein in 83 cases of ESCC and 83 normal esophageal tissues was determined by immunohistochemical staining. Log-rank test and correlation analysis were used to analyze the prognosis of ESCC. The positive expression of P-EGFR in ESCC was 88% (73/83 cases) compared with 41% in normal esophageal mucosa (34/83 cases) (P<0.05). The rate of P-Akt protein expression in ESCC was 90.4% (75/83 cases), compared with 27.7% seen in normal esophageal mucosa (23/83 cases) (P<0.05). The expression of P-EGFR and P-Akt protein was positively correlated with lymph node metastasis and degree of differentiation (P<0.05) irrespective of sex, age, tumor diameter and TNM stage (P>0.05). The expression of P-EGFR was positively correlated with that of P-Akt protein (r=0.674, P<0.01). P-EGFR expression was negatively correlated with survival time of patients with ESCC (r=−0.526, P<0.01). The Kaplan-Meier survival curves showed that the cumulative survival rate of P-EGFR-positive cases was significantly lower than that of the P-EGFR-negative cases (P<0.01). The expression of P-Akt was negatively correlated with survival in patients with ESCC (r=−0.473, P<0.01). The Kaplan-Meier survival curves showed that the cumulative survival rate of the P-Akt-positive cases was significantly lower than that of the P-Akt-negative cases (P<0.01). In conclusion, P-EGFR and P-Akt protein expression is closely related to the incidence of ESCC and mediates the development of invasive cancer and metastasis. It is used to determine the prognosis of ESCC, and may represent a new therapeutic target for the disease.

Comparative molecular profiling of HPV-induced squamous cell carcinomas

Approximately 5% of all cancer incidences result from human papillomavirus (HPV) infection. HPV infection most commonly leads to cancers of the anogenital region or oropharynx. It is unknown whether different HPV-mediated cancers collectively share a molecular signature and it is important to determine if there are targetable alterations common to different types of HPV-positive tumors. We analyzed 743 p53 wild-type samples of anal, cervical, oropharyngeal, and vulvar squamous cell carcinomas which underwent multiplatform testing at a commercial molecular profiling service. Expression of 24 proteins was measured by immunohistochemistry (IHC), mutation of 48 genes was determined by next-generation and Sanger sequencing, and copy number alteration for six genes was determined by in situ hybridization. The four cohorts had remarkably similar molecular profiles. No gene had a statistically significant difference in mutation frequency or copy number change between the four different types of squamous cell carcinomas. The only significant differences between cohorts were frequency of ERCC1 and SPARC loss as determined by IHC. In all four cancer types, oncogene mutation and PD-L1 expression was relatively infrequent. The most commonly mutated gene was PIK3CA, with mutations most often affecting the helical domain of the protein and accompanied by concurrent lack of PTEN expression. Loss of MGMT and RRM1 was common among the four cohorts and may be predictive of response to cytotoxic therapies not currently being used to treat these cancer types. The similar molecular profiles of the four cohorts indicate that treatment strategies may be similarly efficacious across HPV-positive cancers.

Hepatocyte Growth Factor/c-Met Signaling in Head and Neck Cancer and Implications for Treatment

Aberrant signaling of the hepatocyte growth factor (HGF)/c-Met pathway has been identified as a promoter of tumorigenesis in several tumor types including head and neck squamous cell carcinoma (HNSCC). Despite a relatively low c-Met mutation frequency, overexpression of HGF and its receptor c-Met has been observed in more than 80% of HNSCC tumors, with preclinical and clinical studies linking overexpression with cellular proliferation, invasion, migration, and poor prognosis. c-Met is activated by HGF through a paracrine mechanism to promote cellular morphogenesis enabling cells to acquire mesenchymal phenotypes in part through the epithelial-mesenchymal transition, contributing to metastasis. The HGF/c-Met pathway may also act as a resistance mechanism against epidermal growth factor receptor (EGFR) inhibition in advanced HNSCC. Furthermore, with the identification of a biologically distinct subset of HNSCC tumors acquired from human papillomavirus (HPV) infection that generally portends a good prognosis, high expression of HGF or c-Met in HPV-negative tumors has been associated with worse prognosis. Dysregulated HGF/c-Met signaling results in an aggressive HNSCC phenotype which has led to clinical investigations for targeted inhibition of this pathway. In this review, HGF/c-Met signaling, pathway alterations, associations with clinical outcomes, and preclinical and clinical therapeutic strategies for targeting HGF/c-Met signaling in HNSCC are discussed.

IL6 is associated with response to dasatinib and cetuximab: Phase II clinical trial with mechanistic correlatives in cetuximab-resistant head and neck cancer

OBJECTIVE

Src family kinase (SFK) activation circumvents epidermal growth factor receptor (EGFR) targeting in head and neck squamous cell carcinoma (HNSCC); dual SFK-EGFR targeting could overcome cetuximab resistance.

PATIENTS AND METHODS

We conducted a Simon two-stage, phase II trial of the SFK inhibitor, dasatinib, and cetuximab in biomarker-unselected patients with cetuximab-resistant, recurrent/metastatic HNSCC. Pre- and post-treatment serum levels of interleukin-6 (IL6) were measured by ELISA. HNSCC cell lines were assessed for viability and effects of IL6 modulation following dasatinib-cetuximab treatment.

RESULTS

In the first stage, 13 patients were evaluable for response: 7 had progressive and 6 had stable disease (SD). Enrollment was halted for futility, and biomarker analysis initiated. Low serum IL6 levels were associated with SD (raw p=0.028, adjusted p=0.14) and improved overall survival (p=0.010). The IL6 classifier was validated in a separate trial of the same combination, but was unable to segregate survival risk in a clinical trial of cetuximab and bevacizumab suggesting serum IL6 may be specific for the dasatinib-cetuximab combination. Enhanced in vitro HNSCC cell death was observed with dasatinib-cetuximab versus single agent treatment; addition of IL6-containing media abrogated this effect.

CONCLUSION

Clinical benefit and overall survival from the dasatinib-cetuximab combination were improved among patients with low serum IL6. Preclinical studies support IL6 as a modifier of dasatinib-cetuximab response. In the setting of clinical cetuximab resistance, serum IL6 is a candidate predictive marker specific for combined dasatinib-cetuximab. The trial was modified and redesigned as a biomarker-enriched Phase II study enrolling patients with undetectable IL6.

Randomized, placebo-controlled window trial of EGFR, Src, or combined blockade in head and neck cancer

BACKGROUND. EGFR and Src family kinases are upregulated in head and neck squamous cell carcinoma (HNSCC). EGFR interacts with Src to activate STAT3 signaling, and dual EGFR-Src targeting is synergistic in HNSCC preclinical models. pSrc overexpression predicted resistance to the EGFR inhibitor, erlotinib, in a prior window trial. We conducted a 4-arm window trial to identify biomarkers associated with response to EGFR and/or Src inhibition. METHODS. Patients with operable stage II-IVa HNSCC were randomized to 7-21 days of neoadjuvant erlotinib, the Src inhibitor dasatinib, the combination of both, or placebo. Paired tumor specimens were collected before and after treatment. Pharmacodynamic expression of EGFR and Src pathway components was evaluated by IHC of tissue microarrays and reverse-phase protein array of tissue lysates. Candidate biomarkers were assessed for correlation with change in tumor size. RESULTS. From April 2009 to December 2012, 58 patients were randomized and 55 were treated. There was a significant decrease in tumor size in both erlotinib arms (P = 0.0014); however, no effect was seen with dasatinib alone (P = 0.24). High baseline pMAPK expression was associated with response to erlotinib (P = 0.03). High baseline pSTAT3 was associated with resistance to dasatinib (P = 0.099). CONCLUSIONS. Brief exposure to erlotinib significantly decreased tumor size in operable HNSCC, with no additive effect from dasatinib. Baseline pMAPK expression warrants further study as a response biomarker for anti-EGFR therapy. Basal expression of pSTAT3 may be independent of Src, explain therapeutic resistance, and preclude development of dasatinib in biomarker-unselected cohorts. TRIAL REGISTRATION. NCT00779389. FUNDING. National Cancer Institute, American Cancer Society, Pennsylvania Department of Health, V Foundation for Cancer Research, Bristol-Myers Squibb, and Astellas Pharma.

Systemic Treatment in HPV-Induced Recurrent or Metastatic HNSCC

Recurrent or metastatic head and neck cancer describes tumor deposits that arise locally, regionally, or at distant sites after treatment or distant metastases at the time of primary diagnosis. Prognosis for R/M squamous cell carcinomas of the head and neck (HNSCC) is poor and treatment options are limited in this situation. Human papillomavirus (HPV) is an important risk factor for HNSCC. About 40 % of all HNSCC have been attributed to HPV in Europe. HPV positivity at initial diagnosis is the single best prognostic factor for survival. However, data for the prognostic and predictive value of HPV in the R/M situation are still scarce. Due to the rising incidence of HPV-associated cancers, the number of R/M HPV+ carcinomas is also expected to rise. This chapter therefore aims to give an overview of the current knowledge concerning the role of HPV as a prognostic and predictive marker in recurrent or metastatic HNSCC.

Cetuximab Resistance in Head and Neck Cancer Is Mediated by EGFR-K521 Polymorphism

Head and neck squamous cell carcinomas (HNSCC) exhibiting resistance to the EGFR-targeting drug cetuximab poses a challenge to their effective clinical management. Here, we report a specific mechanism of resistance in this setting based upon the presence of a single nucleotide polymorphism encoding EGFR-K₅₂₁ (K-allele), which is expressed in >40% of HNSCC cases. Patients expressing the K-allele showed significantly shorter progression-free survival upon palliative treatment with cetuximab plus chemotherapy or radiation. In several EGFR-mediated cancer models, cetuximab failed to inhibit downstream signaling or to kill cells harboring a high K-allele frequency. Cetuximab affinity for EGFR-K₅₂₁ was reduced slightly, but ligand-mediated EGFR activation was intact. We found a lack of glycan sialyation on EGFR-K₅₂₁ that associated with reduced protein stability, suggesting a structural basis for reduced cetuximab efficacy. CetuGEX, an antibody with optimized Fc glycosylation targeting the same epitope as cetuximab, restored HNSCC sensitivity in a manner associated with antibody-dependent cellular cytotoxicity rather than EGFR pathway inhibition. Overall, our results highlight EGFR-K₅₂₁ expression as a key mechanism of cetuximab resistance to evaluate prospectively as a predictive biomarker in HNSCC patients. Further, they offer a preclinical rationale for the use of ADCC-optimized antibodies to treat tumors harboring this EGFR isoform. Cancer Res; 77(5); 1188-99. ©2016 AACR.

Defining the boundaries and expanding the utility of head and neck cancer patient derived xenografts

BACKGROUND

Patient derived xenografts (PDXs) represent an essential tool in oncologic research, and we sought to further expand our repertoire of head and neck squamous cell carcinoma (HNSCC) while determining potential boundaries for this system.

METHODS

We consented new patients for PDX development and determined if a 24-h time delay from tumor excision to xenograft implantation affected PDX establishment. We developed a tissue microarray (TMA) from formalin fixed, paraffin embedded PDXs and their subsequent passages and carried out quantitative immunohistochemistry for EGFR, pEGFR, pAkt, pERK and ERCC1. First and last passaged PDXs were compared via a paired t-test to examine for the stability of protein expression across passages. We performed a similar comparison of the mutational profile of the patient tumor and resulting xenografts using a targeted sequencing approach.

RESULTS

No patient/tumor characteristics influenced PDX take rate and the 24-h time delay from tumor excision to xenograft implantation did not affect PDX establishment, growth or histology. There was no significant difference in biomarker expression between the first and last passaged PDXs for EGFR, pEGFR, pAkt, and ERCC1. For pERK there was a significant difference (p=0.002), but further analysis demonstrated this only arose in three of 15 PDXs. Targeted sequencing revealed striking stability of passenger and likely driver mutations from patient to xenograft.

CONCLUSIONS

The stability of protein expression across PDX passages will hopefully allow greater investigation of predictive biomarkers in order to identify ones for further pre-clinical and clinical investigation.

Targeted Therapy of Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is one of the most common solid cancers worldwide. It is mainly caused by exposure to tobacco smoke and alcohol as well as infection with the human papilloma virus (HPV). The prognosis is poor, especially once it recurs or metastasizes. Current therapeutic options include surgery, radio- and chemotherapy. Epidermal growth factor receptor (EGFR) inhibitors are so far the only targeted agents that have been approved in head and neck cancer. Primary or secondary resistance is frequent or will eventually develop. Several driver mutations and other genomic aberrations have been described in HNSCC including EGFR overexpression and amplification. Yet, no predictive biomarkers for the application of EGFR inhibitors have been identified. Further targeted agents are in development for HNSCC, of which inhibitors of the PI3K pathway are the closest to clinical application. In recent years, the incidence of HPV-driven HNSCC has risen in Western countries. HPV-positive and -negative HNSCC are distinct molecular tumor entities, and consequences for targeted therapies have been discussed. This review looks at approved and investigational targeted treatment strategies as well as potential predictive biomarkers such as the HPV status to guide treatment.

Blood-based markers of efficacy and resistance to cetuximab treatment in metastatic colorectal cancer: results from CALGB 80203 (Alliance)

Circulating protein markers were assessed in patients with colorectal cancer (CRC) treated with cetuximab in CALGB 80203 to identify prognostic and predictive biomarkers. Patients with locally advanced or metastatic CRC received FOLFOX or FOLFIRI chemotherapy (chemo) or chemo in combination with cetuximab. Baseline plasma samples from 152 patients were analyzed for six candidate markers [epidermal growth factor (EGF), heparin‐binding EGF (HBEGF), epidermal growth factor receptor (EGFR), HER2, HER3, and CD73]. Analyte levels were associated with survival endpoints using univariate Cox proportional hazards models. Predictive markers were identified using a treatment‐by‐marker interaction term in the Cox model. Plasma levels of EGF, HBEGF, HER3, and CD73 were prognostic for overall survival (OS) across all patients (KRAS mutant and wild‐type). High levels of EGF predicted for lack of OS benefit from cetuximab in KRAS wild‐type (WT) patients (chemo HR = 0.98, 95% CI = 0.74–1.29; chemo+cetuximab HR = 1.54, 95% CI = 1.05–2.25; interaction P = 0.045) and benefit from cetuximab in KRAS mutant patients (chemo HR = 1.72, 95% CI = 1.02–2.92; chemo+cetuximab HR = 0.90, 95% CI = 0.67–1.21; interaction P = 0.026). Across all patients, higher HER3 levels were associated with significant OS benefit from cetuximab treatment (chemo HR = 4.82, 95% CI = 1.68–13.84; chemo+cetuximab HR = 0.95, 95% CI = 0.31–2.95; interaction P = 0.046). CD73 was also identified as predictive of OS benefit in KRASWT patients (chemo HR = 1.28, 95% CI = 0.88–1.84; chemo+cetuximab HR = 0.60, 95% CI = 0.32–1.13; interaction P = 0.049). Although these results are preliminary, and confirmatory studies are necessary before clinical application, the data suggest that HER3 and CD73 may play important roles in the biological response to cetuximab.

Targeting pathways mediating resistance to anti-EGFR therapy in squamous cell carcinoma of the head and neck

INTRODUCTION

As epidermal growth factor receptor (EGFR) is overexpressed in approximately 90% of squamous cell carcinomas of the head and neck (SCCHN), several therapeutic agents that target EGFR have been evaluated for the treatment of SCCHN. Although patients with SCCHN derive clinical benefit from anti-EGFR agents, most notably the EGFR monoclonal antibody cetuximab, these patients eventually become resistant to EGFR-based therapies; preclinical studies have shown activation of secondary signaling pathways that lead to resistance to EGFR inhibition and, as such, serve as potential therapeutic targets to overcome resistance to EGFR inhibitors.

AREAS COVERED

This review summarizes the results of recently completed trials of anti-EGFR agents in SCCHN, highlights the various mechanisms that drive resistance to EGFR inhibitors in SCCHN, and focuses on several novel targeted agents that could potentially help overcome resistance to EGFR-based therapies in SCCHN. Expert commentary: Due to the development of resistance to EGFR-targeted therapies, novel treatment approaches to overcome resistance are a key unmet need for SCCHN.

Preclinical and clinical studies on afatinib in monotherapy and in combination regimens: Potential impact in colorectal cancer

Targeting the epidermal growth factor receptor (EGFR) with monoclonal antibodies (mAbs) or tyrosine kinase inhibitors (TKI) has been an interesting therapeutic strategy because aberrant activation of this receptor plays an important role in the tumorgenesis of many cancer types, including colorectal cancer (CRC). After the initial promising results of EGFR-targeted therapies, therapeutic resistance is a major clinical problem. In order to overcome resistance to these EGFR-targeted therapies, new treatment options are necessary. In contrast to first generation EGFR inhibitors, afatinib (BIBW2992) is a second-generation irreversible ErbB family blocker that inhibits EGFR as well as HER2 and HER4. Consequently, treatment with afatinib may result in a distinct and more pronounced therapeutic benefit. Preclinical studies have reported promising results for afatinib in monotherapy as well as in combination with other drugs in CRC model systems. Furthermore, clinical studies examining afatinib as single agent and in combination therapy demonstrated manageable safety profile. Nevertheless, only limited antitumor activity has been observed in CRC patients. Although several combination treatments with afatinib have already been investigated, no optimal combination has been identified for CRC patients yet. As molecular tumor characteristics have gained increased importance in the choice of treatment, additional studies with biomarker-driven patient recruitment are required to further explore afatinib efficacy in CRC.

Genomically personalized therapy in head and neck cancer

The current treatment paradigm in head and neck cancer does not adequately address its clinical and biological heterogeneity. Data from genomic profiling studies in head and neck squamous cell carcinoma (HNSCC) have revealed the molecular features that are unique to HNSCC subgroups. This progress in the understanding of HNSCC biology provides an opportunity to develop personalized therapies for patients with distinct molecular subtypes to achieve better clinical outcomes including survival. However there are several well-recognized challenges that need to be overcome before genotype-matched therapies make precision medicine a reality for patients with HNSCC. Selection of appropriate patients for biomarker directed clinical trials based on sound scientific rationale will be critical in making cancer genomics more applicable in this malignancy.

Immunotherapy for Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma has been found to be an immunosuppressive malignancy, with many defects in the host immune system contributing to the progression of disease. A greater understanding of these defects has lead to the identification and investigation of new therapeutic strategies, targeting immune system dysfunction in an effort to improve the outcomes of this disease. This article provides a brief review of the knowledge regarding the immune defects present in head and neck cancer, as well as a review of the current therapeutic strategies being investigated for use.

The EGFR-specific antibody cetuximab combined with chemotherapy triggers immunogenic cell death

Cetuximab is a monoclonal antibody that is effective in the treatment of metastatic colorectal cancer (mCRC). Cetuximab blocks epidermal growth factor receptor (EGFR)-ligand interaction and inhibits downstream RAS-ERK activation. However, only some activating mutations in RAS affect cetuximab efficacy, and it is not clear what else mediates treatment success. Here we hypothesized that cetuximab induces immunogenic cell death (ICD) that activates a potent antitumor response. We found that cetuximab, in combination with chemotherapy, fostered ICD in CRC cells, which we measured via the endoplasmic reticulum (ER) stress response and an increase in phagocytosis by dendritic cells. ICD induction depended on the mutational status of the EGFR signaling pathway and on the inhibition of the splicing of X-box binding protein 1 (XBP1), an unfolded protein response (UPR) mediator. We confirmed the enhanced immunogenicity elicited by cetuximab in a mouse model of human EGFR-expressing CRC. Overall, we demonstrate a new, immune-related mechanism of action of cetuximab that may help to tailor personalized medicine.

Heads Up! Predictive Gene Signatures in Head and Neck Cancer May Be Coming Soon

Cetuximab-platinum chemotherapy is used for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC); however, a minority of patients benefit. Gene expression profiling (GEP) of HNSCCs with prolonged responses to cetuximab-chemotherapy demonstrate basal subtype traits including signatures of EGFR signaling and hypoxic differentiation. GEP of short-response patients show RAS activation. Clin Cancer Res; 22(15); 3710-2. ©2016 AACRSee related article by Bossi et al., p. 3961.

Functional Genomics Uncover the Biology behind the Responsiveness of Head and Neck Squamous Cell Cancer Patients to Cetuximab

PURPOSE

To identify the tumor portrait of the minority of head and neck squamous cell carcinoma (HNSCC) patients with recurrent-metastatic (RM) disease who upon treatment with platinum-based chemotherapy plus cetuximab present a long-lasting response.

EXPERIMENTAL DESIGN

The gene expression of pretreatment samples from 40 HNSCC-RM patients, divided in two groups [14 long-progression-free survival (PFS) and 26 short-PFS (median = 19 and 3 months, respectively)], was associated with PFS and was challenged against a dataset from metastatic colon cancer patients treated with cetuximab. For biologic analysis, we performed functional and subtype association using gene set enrichment analysis, associated biology across all currently available HNSCC signatures, and inferred drug sensitivity using data from the Cancer Genomic Project.

RESULTS

The identified genomic profile exhibited a significant predictive value that was essentially confirmed in the single publicly available dataset of cetuximab-treated patients. The main divergence between long- and short-PFS groups was based on developmental/differentiation status. The long-PFS patients are characterized by basal subtype traits such as strong EGFR signaling phenotype and hypoxic differentiation, further validated by the significantly higher association with the hypoxia metagene. The short-PFS patients presented a strong activation of RAS signaling confirmed in an in vitro model of two isogenic HNSCC cell lines sensitive or resistant to cetuximab. The predicted drug sensitivity for all four EGFR inhibitors was higher in long- versus short-PFS patients (P range: <0.0022-1e-07).

CONCLUSIONS

Our data uncover the biology behind response to platinum-based chemotherapy plus cetuximab in RM-HNSCC cancer and may have translational implications improving treatment selection. Clin Cancer Res; 22(15); 3961-70. ©2016 AACRSee related commentary by Chau and Hammerman, p. 3710.

Phase II study of necitumumab plus modified FOLFOX6 as first-line treatment in patients with locally advanced or metastatic colorectal cancer

BACKGROUND

This single-arm phase II study investigated the EGFR monoclonal antibody necitumumab plus modified FOLFOX6 (mFOLFOX6) in first-line treatment of locally advanced or metastatic colorectal cancer (mCRC).

METHODS

Patients received 800-mg intravenous necitumumab (day 1; 2-week cycles), followed by oxaliplatin 85 mg m(-2), folinic acid 400 mg m(-2), and 5-fluorouracil (400 mg m(-2) bolus then 2400 mg m(-2) over 46 h). Radiographic evaluation was performed every 8 weeks until progression. Primary endpoint was objective response rate.

RESULTS

Forty-four patients were enrolled and treated. Objective response rate was 63.6% (95% confidence interval 47.8-77.6); complete response was observed in four patients; median duration of response was 10.0 months (7.0-16.0). Median overall survival (OS) and progression-free survival (PFS) were 22.5 (11.0-30.0) and 10.0 months (7.0-12.0), respectively. Clinical outcome was better in patients with KRAS exon 2 wild type (median OS 30.0 months (23.0-NA); median PFS 12.0 (8.0-20.0)), compared with KRAS exon 2 mutant tumours (median OS 7.0 months (5.0-37.0); median PFS 7.0 (4.0-18.0)). The most common grade ⩾3 adverse events were neutropenia (29.5%), asthenia (27.3%), and rash (20.5%).

CONCLUSION

First-line necitumumab+mFOLFOX6 was active with manageable toxicity in locally advanced or mCRC; additional evaluation of the impact of tumour RAS mutation status is warranted.

Comprehensive multiplatform biomarker analysis of 199 anal squamous cell carcinomas

Anal squamous cell carcinoma (ASCC) is a rare, HPV-associated malignancy typically diagnosed in early stages and definitively treated with chemoradiation. In situations where patients exhibit metastatic or recurrent disease, treatment options are severely limited. In this study, molecular alterations were identified that could be used to aid in therapeutic decisions for patients with metastatic or recurrent anal squamous cell carcinoma. Specimens from patients with this cancer were tested via a multiplatform profiling service (Caris Life Sciences, Phoenix, AZ) consisting of gene sequencing, protein expression by immunohistochemistry, and gene amplification with in situ hybridization. Utilizing these techniques, novel treatment strategies that could be explored were identified, including potential benefit with anti-EGFR therapies, immune checkpoint inhibitors, topoisomerase inhibitors, and taxanes. The frequency of overexpression of proteins that mark resistance to chemotherapeutic drugs, such as MRP1 (chemotherapy efflux pump), ERCC1 (resistance to platinum-based chemotherapy), and thymidylate synthase (resistance to fluoropyrimidines) were also identified, suggesting a lack of benefit. This multiplatform strategy could be explored for its potential to generate a personalized treatment selection for patients with advanced ASCC, provide a guide for future therapeutic development for this cancer, and be extended to other rare cancer types as well.

Molecular profiling of head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) exhibits high rates of recurrence, and with few approved targeted agents, novel treatments are needed. We analyzed a molecular profiling database for the distribution of biomarkers predictive of chemotherapies and targeted agents.

Methods

Seven hundred thirty‐five patients with advanced HNSCC (88 with known human papillomavirus [HPV] status), were profiled using multiple platforms (gene sequencing, gene copy number, and protein expression).

Results

Among the entire patient population studied, epidermal growth factor receptor (EGFR) was the protein most often overexpressed (90%), TP53 gene most often mutated (41%), and phosphatidylinositol 3‐kinase (PIK3CA) most often amplified (40%; n = 5). With the exception of TP53 mutation, other biomarker frequencies were not significantly different among HPV‐positive or HPV‐negative patients. PIK3CA mutations and phosphatase and tensin homolog (PTEN) loss are frequent events, independent of HPV status. The immune response‐modulating programmed cell death 1 (PD1) and programmed cell death ligand 1 (PDL1) axis was active across sites, stages, and HPV status.

Conclusion

Molecular profiling utilizing multiple platforms provides a range of therapy options beyond standard of care. © 2015 Wiley Periodicals, Inc. Head Neck38: E1625–E1638, 2016

Management of locally advanced HPV-related oropharyngeal squamous cell carcinoma: where are we?

HPV-related (HPV+) oropharyngeal cancer (OPC) has a better prognosis compared to HPV unrelated (HPV-) OPC. This review summarizes and discusses several of the controversies regarding the management of HPV+ OPC, including the mechanism of its treatment sensitivity, modern surgical techniques, chemotherapy regimens, and treatment de-intensification protocols. We also discuss and reconsider potential adverse prognostic factors such as tumor EGFR expression, tumor hypoxia, and patient smoking history, as well as the significance of retropharyngeal adenopathy. Finally, we discuss elective nodal treatment of uninvolved lymph node stations. While this review does not exhaust all controversies related to the management of HPV+ OPC, it aims to highlight some of the most clinically relevant ones.

Targeted therapy in cancer

PURPOSE

To describe the emergence of targeted therapies that have led to significant breakthroughs in cancer therapy and completed or ongoing clinical trials of novel agents for the treatment of patients with advanced cancer.

METHODS

The literature was systematically reviewed, based on clinical experience and the use of technologies that improved our understanding of carcinogenesis.

RESULTS

Genomics and model systems have enabled the validation of novel therapeutic strategies. Tumor molecular profiling has enabled the reclassification of cancer and elucidated some mechanisms of disease progression or resistance to treatment, the heterogeneity between primary and metastatic tumors, and the dynamic changes of tumor molecular profiling over time. Despite the notable technologic advances, there is a gap between the plethora of preclinical data and the lack of effective therapies, which is attributed to suboptimal drug development for "driver" alterations of human cancer, the high cost of clinical trials and available drugs, and limited access of patients to clinical trials. Bioinformatic analyses of complex data to characterize tumor biology, function, and the dynamic tumor changes in time and space may improve cancer diagnosis. The application of discoveries in cancer biology in clinic holds the promise to improve the clinical outcomes in a large scale of patients with cancer. Increased harmonization between discoveries, policies, and practices will expedite the development of anticancer drugs and will accelerate the implementation of precision medicine.

CONCLUSIONS

Combinations of targeted, immunomodulating, antiangiogenic, or chemotherapeutic agents are in clinical development. Innovative adaptive study design is used to expedite effective drug development.

Current Treatment Options for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

This review highlights the evidence-based data to support current best management practices for patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Current limitations and areas of emerging therapeutics are also emphasized. The cornerstone of palliation for patients with R/M HNSCC is a platinum-based backbone. Platinum doublets induce higher response rates than single agents but do not demonstrate a survival advantage and are associated with increased toxicity. The only regimen to demonstrate survival superiority is platinum, fluorouracil, and cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor (EGFR). EGFR inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors, have achieved only modest success in R/M HNSCC, illustrating the importance of identifying predictive biomarkers and finding ways to overcome mechanisms of resistance. Although phosphoinositide 3-kinase pathway alterations are present at a high rate in HNSCC, the identification of efficacious agents in patients with activating alterations has yet to be discovered. Immunotherapy represents an attractive treatment strategy for R/M HNSCC, with promising preliminary data from studies involving immune checkpoint blockade and toll-like receptor agonists. Human papillomavirus has a prognostic role in R/M disease; therefore, stratification of patients by human papillomavirus status in clinical trials is indicated. Although under-represented in clinical trials, elderly patients experience similar survival outcomes compared with younger patients, albeit with increased toxicity. Despite therapeutic advances, prognosis nonetheless remains poor for patients with R/M HNSCC. Enrollment of patients onto clinical trials to investigate novel therapeutics and identify predictive biomarkers is necessary to further refine and improve outcomes.

Heregulin and HER3 are prognostic biomarkers in oropharyngeal squamous cell carcinoma

BACKGROUND

Although heregulin and human epidermal growth factor receptor 3 (HER3) are frequently expressed at high levels in patients with head and neck cancer, their prognostic value remains unclear. The authors explored the prognostic significance of heregulin/HER3 expression in patients with oropharyngeal squamous cell carcinoma (OPSCC), taking into account other HER family members as well as p16 status.

METHODS

Ninety-six primary tumor specimens from patients with OPSCC were retrospectively collected and analyzed for heregulin messenger RNA (mRNA) using in situ hybridization and for HER3, epidermal growth factor receptor, and human epidermal growth factor receptor 2 (HER2) using quantitative immunohistochemistry. Heregulin and HER3 mRNA levels were also examined among different tumor types using The Cancer Genome Atlas database.

RESULTS

High heregulin mRNA (> the median) correlated significantly with poor overall survival (OS) (hazard ratio [HR], 8.48; 95% confidence interval [95% CI], 2.17-33.17 [P =.002]) but not disease-free survival (HR, 1.52; 95% CI, 0.64-3.65 [P =.341]) in patients with OPSCC. Heregulin mRNA correlated negatively with OS in both patients with p16-positive (P =.049) and p16-negative (P =.091) OPSCC on univariate analysis. High HER3 (> the median) also correlated with poor OS (HR, 4.68; 95% CI, 1.47-14.90 [P =.009]) on multivariate analysis. Epidermal growth factor receptor levels independently correlated with disease-free survival (P =.025) and inversely correlated with p16 status (P =.012). In addition, The Cancer Genome Atlas data demonstrated that head and neck squamous cell carcinoma exhibits higher heregulin expression compared with other solid tumor types examined.

CONCLUSIONS

High heregulin mRNA and high HER3 protein levels were found to independently correlate with poor OS in patients with OPSCC. These data support targeting HER3 in patients with heregulin-high OPSCC and warrant further clinical investigation.

Correlations between prognosis and regional biomarker profiles in head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCC) show diverse clinicopathological features and are mostly linked with poor outcome. In this study, we tested if the expression of tumor growth, cell cycle and basement membrane anchorage related biomarkers allow prognostic and clinicopathological stratification of HNSCC. Archived HNSCC samples from 226 patients included into tissue microarrays (TMA) were tested using immunohistochemistry. Histopathological evaluation and the analysis of immunostaining for EGFR, Ki67, p53, p16(ink4) and Collagen XVII proteins were carried out in digital whole slides. Statistical evaluation was carried out using Pearson's Chi-square test and Kaplan-Meier survival analysis. In the tested cohort, hypopharyngeal cancers had the least favorable, and glottic cancers had the most favorable prognosis. High Ki67 positive tumor cell fractions were associated with significantly worse prognosis and elevated rate of lymph node metastasis. Both Ki67 and EGFR expression correlated significantly with the tumor localization. Ki67 index was the highest in the hypopharyngeal region and it proved to be the lowest in the glottic region. EGFR expression was the highest in the oral cavity and the lowest in the glottic region. The survival rate of patients with p16(ink4)-negative cancer was significantly lower than of those with p16(ink4)-positive disease. A significant inverse correlation was found between histological grade and the prognosis of HNSCC. Our data support that elevated Ki67 positive proliferating cell fractions contribute to the unfavorable prognosis of hypopharyngeal cancers, while glottic cancers have the most favorable prognosis because of the lowest Ki67 expression rate.

S-1 and Cisplatin With or Without Nimotuzumab for Patients With Untreated Unresectable or Metastatic Gastric Cancer: A Randomized, Open-Label Phase 2 Trial

This open-label, randomized phase II trial was performed to compare the efficacy and safety of nimotuzumab plus S-1 and cisplatin (NCS) versus S-1 and cisplatin (CS) alone in patients with untreated unresectable or metastatic gastric cancer in the first-line setting. Eligible participants were randomly assigned (1:1) to receive either NCS or CS. The treatment consisted of 3-week cycles of twice-daily S-1 40 mg/m² (on days 1-14) and intravenous cisplatin 30 mg/m² (on days 1, 2), with or without weekly nimotuzumab (200 mg/m²). The primary endpoint was objective response rate (ORR). The second endpoint included progression-free survival (PFS), overall survival (OS), safety and association between efficacy and tumor epidermal growth factor receptor (EGFR) expression. Between October, 2009, and February, 2012, we enrolled 62 patients in Cancer Hospital Chinese Academy of Medical Sciences (CAMS). The ORR for 31 patients allocated NCS was 54.8% compared with 58.1% for 31 patients who were allocated to receive CS alone (P = 0.798). Median PFS for patients in CS arm was significantly improved than that in NCS arm [7.2 months vs. 4.8 months HR = 2.136 (95% CI 1.193-3.826), P = 0.011]. There was also a trend toward better overall survival for patients in CS arm compared with NCS arm [14.3 months vs. 10.2 months; HR = 1.776 (95% CI 0.972-3.246), P = 0.062]. In the EGFR 2+/3+ subgroup, adding nimotuzumab also failed to show additional benefit than chemotherapy alone. Both groups were well tolerated. Less than 10% of patients in both arms developed grade 3/4 toxicity. Combination of nimotuzumab and S-1-cisplatin provided no additional benefit than chemotherapy alone in the first-line treatment of unresectable or metastatic gastric cancer.

Tumor and stromal-based contributions to head and neck squamous cell carcinoma invasion

Head and neck squamous cell carcinoma (HNSCC) is typically diagnosed at advanced stages with evident loco-regional and/or distal metastases. The prevalence of metastatic lesions directly correlates with poor patient outcome, resulting in high patient mortality rates following metastatic development. The progression to metastatic disease requires changes not only in the carcinoma cells, but also in the surrounding stromal cells and tumor microenvironment. Within the microenvironment, acellular contributions from the surrounding extracellular matrix, along with contributions from various infiltrating immune cells, tumor associated fibroblasts, and endothelial cells facilitate the spread of tumor cells from the primary site to the rest of the body. Thus far, most attempts to limit metastatic spread through therapeutic intervention have failed to show patient benefit in clinic trails. The goal of this review is highlight the complexity of invasion-promoting interactions in the HNSCC tumor microenvironment, focusing on contributions from tumor and stromal cells in order to assist future therapeutic development and patient treatment.

PIK3CA Pathway Mutations Predictive of Poor Response Following Standard Radiochemotherapy ± Cetuximab in Cervical Cancer Patients

PURPOSE

EGFR is frequently overexpressed in cervical cancer, suggesting EGFR blockade as a promising treatment approach. Cetuximab, an anti EGFR antibody, used conjointly with radiochemotherapy, was feasible in first-line treatment of cervix carcinoma limited to the pelvis.

EXPERIMENTAL DESIGN

This randomized phase II trial enrolled 78 FIGO stage IB2-IIIB cervical cancer patients to either cisplatin-based radiochemotherapy alone (arm B, n = 38) or conjointly with a 6-week course of weekly cetuximab (arm A, n = 40). Brachytherapy was given to the pelvic mass. Primary endpoint was disease-free survival (DFS) at 2 years. EGFR expression and targeted sequencing were performed in 54 of 78 patients.

RESULTS

Cetuximab over a 6-week period did not improve DFS at 24 months. At 31 months median follow-up, DFS was not significantly different (P = 0.18). Complete response at 4 to 6 months was strongly predictive for excellent DFS (log-rank test; P < 0.001). PIK3CA, KRAS, and STK11 mutations were observed in 22%, 4%, and 2% of patients, respectively. No tumor with a PI3K pathway mutation showed complete response (0/8 in arm A and 0/6 in arm B), whereas 14 of 52 (27%) tumors without mutations did (P = 0.021). PI3K pathway-mutated tumors showed a trend toward poorer DFS (P = 0.06) following cetuximab (8/22) as compared with those following standard treatment only (6/18).

CONCLUSIONS

Similar to patients with head and neck cancer, patients with cervical cancer showed no gain in DFS at 2 years following a combined treatment of cetuximab with radiochemotherapy. Although treatment tolerance and compliance were satisfactory, it remains to be demonstrated whether maintenance therapy with cetuximab could be beneficial in selected patient groups.

Mechanisms of and therapeutic approaches for overcoming resistance to epidermal growth factor receptor (EGFR)-targeted therapy in squamous cell carcinoma of the head and neck (SCCHN)

The majority of squamous cell carcinoma of the head and neck (SCCHN) overexpress epidermal growth factor receptor (EGFR), which has been associated with poor treatment response and survival. However, only modest success has been achieved with the use of single agents that target EGFR, possibly due to primary and acquired resistance. This review will discuss key mechanisms of and therapeutic approaches to overcoming resistance to EGFR-targeted therapy in SCCHN. Recent preclinical and clinical investigations have demonstrated that other ErbB family receptors (eg, HER2 and HER3) and other horizontal resistance mechanisms, as well as activation of downstream signaling pathways, epigenetic events, and nuclear EGFR, are possible mediators of resistance to anti-EGFR therapeutics. Key downstream pathways that may be implicated in EGFR resistance include phosphatidylinositol-3-kinase/protein kinase B, vascular endothelial growth factor (VEGF), and mammalian target of rapamycin (mTOR). Multiple agents that target EGFR and other ErbB family members (ie, lapatinib, afatinib, and dacomitinib), as well as combination therapies that target EGFR and selected other pathways (eg, VEGF, mTOR, and c-Met) are being investigated clinically. In addition, several phase II and III trials continue to investigate strategies to enhance the efficacy of EGFR-targeted therapy in SCCHN.

Phase II clinical and exploratory biomarker study of dacomitinib in patients with recurrent and/or metastatic squamous cell carcinoma of head and neck

PURPOSE

The goals of this study were to investigate the clinical activity, safety, and biomarkers of dacomitinib, an irreversible tyrosine kinase inhibitor of EGFR, HER2, and HER4, in recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M-SCCHN).

EXPERIMENTAL DESIGN

Patients were eligible if the diseases were not amenable to curative treatment and had progressed on platinum-based chemotherapy, and were treated with dacomitinib 45 mg/day. The primary endpoint was objective response rate by RECISTv1.1. Exploratory analysis included the characterization of somatic mutation, gene copy number, gene expression, p16(INK4A) expression by IHC, and investigation of their relationship with clinical outcomes.

RESULTS

Forty-eight patients were evaluable for efficacy and toxicity. Ten patients (20.8%) had partial responses and 31 patients (65%) had stable diseases. The median progression-free survival (PFS) and overall survival (OS) were 3.9 months [95% confidence interval (CI), 2.9-5.0] and 6.6 months (95% CI, 5.4-10.3). Adverse events were mostly grade 1-2. Mutations in the PI3K pathway (PIK3CA, PTEN) and high expression of inflammatory cytokines (IL6, IL8, IL1A, IL1B, IL4, and TNF) were significantly associated with shorter PFS (2.9 vs. 4.9 months without mutations, P = 0.013; 2.8 vs. 9.9 months with low expression, P = 0.004). Those harboring PI3K pathway mutations or high inflammatory cytokine expression had shorter median OS (6.1 vs. 12.5 months lacking PI3K pathway mutations and with low inflammatory cytokine expression, P = 0.005).

CONCLUSIONS

Dacomitinib demonstrated clinical efficacy with manageable toxicity in platinum-failed R/M-SCCHN patients. Screening of PI3K pathway mutation and inflammatory cytokine expression may help identify which R/M-SCCHN patients are likely to gain benefit from dacomitinib.

Xenograft assessment of predictive biomarkers for standard head and neck cancer therapies

Head and neck squamous cell carcinoma (HNSCC) remains a challenging cancer to treat with overall 5-year survival on the order of 50–60%. Therefore, predictive biomarkers for this disease would be valuable to provide more effective and individualized therapeutic approaches for these patients. While prognostic biomarkers such as p16 expression correlate with outcome; to date, no predictive biomarkers have been clinically validated for HNSCC. We generated xenografts in immunocompromised mice from six established HNSCC cell lines and evaluated response to cisplatin, cetuximab, and radiation. Tissue microarrays were constructed from pre- and posttreatment tumor samples derived from each xenograft experiment. Quantitative immunohistochemistry was performed using a semiautomated imaging and analysis platform to determine the relative expression of five potential predictive biomarkers: epidermal growth factor receptor (EGFR), phospho-EGFR, phospho-Akt, phospho-ERK, and excision repair cross-complementation group 1 (ERCC1). Biomarker levels were compared between xenografts that were sensitive versus resistant to a specific therapy utilizing a two-sample t-test with equal standard deviations. Indeed the xenografts displayed heterogeneous responses to each treatment, and we linked a number of baseline biomarker levels to response. This included low ERCC1 being associated with cisplatin sensitivity, low phospho-Akt correlated with cetuximab sensitivity, and high total EGFR was related to radiation resistance. Overall, we developed a systematic approach to identifying predictive biomarkers and demonstrated several connections between biomarker levels and treatment response. Despite these promising initial results, this work requires additional preclinical validation, likely involving the use of patient-derived xenografts, prior to moving into the clinical realm for confirmation among patients with HNSCC.

Immunotherapy for head and neck squamous cell carcinoma

OBJECTIVES

To review the current state of immunotherapy of head and neck squamous cell carcinoma.

MATERIALS AND METHODS

Review of the literature with emphasis on clinical trial data.

RESULTS

Patients with head and neck squamous cell carcinoma (HNSCC) have long been known to be immunosuppressed. This impairment of the immune system is believed, at least in part, to underlie the poor outcomes in this patient population. Modulating the immune system to improve cancer outcomes is an attractive concept in this difficult to treat population.

CONCLUSION

New studies have started to unravel the mechanisms of immunosuppression and new therapies are being developed to exploit this new information.

Novel treatments for head and neck squamous cell carcinoma: preclinical identification and clinical investigation

Head and neck squamous cell carcinoma (HNSCC) is a common cancer worldwide. Classically, it is a disease related to tobacco and alcohol use; an increasing number of patients are being diagnosed with HNSCC caused by infection with the human papillomavirus. New deep-sequencing techniques have confirmed the importance of p53 and EGF receptor in HNSCC development, and have identified pathways of critical importance, such as PI3K/mTOR and NOTCH. Increasing knowledge of key molecular features has lead to new therapeutic avenues for HNSCC. Novel therapies under investigation in HNSCC include antibody and small molecule inhibitors of EGF receptor and its family members, PI3K inhibitors, antiangiogenic agents, immunotherapies and agents interacting with early developmental pathways such as Hedgehog.

EGFR methylation and outcome of patients with advanced colorectal cancer treated with cetuximab

Targeted therapy of metastatic colorectal cancer (mCRC) with monoclonal antibody anti-epidermal growth factor receptor (EGFR) agents, such as cetuximab (CTX) or panitumumab, is the treatment strategy of choice in patients characterised by a wild-type (wt) RAS gene status. However, despite selection based on RAS status, a high proportion of patients do not respond to therapy. EGFR methylation has been reported to have a role in predicting the response to anti-EGFR agents. The present study aimed to evaluate the role of EGFR methylation in association with the clinical outcome of patients with mCRC treated with CTX. In total, 64 patients with mCRC were assessed in the present study. Genomic DNA was extracted from tumoral tissue and EGFR methylation and mutation of the KRAS, BRAF and PIK3CA genes were analysed by pyrosequencing. EGFR expression was assessed by immunohistochemistry. The various alterations were analysed by assessing the objective response rate (ORR), progression free survival (PFS) and overall survival (OS) rates. In total, 42 cases (66%) exhibited >10% EGFR methylation and there was no correlation with EGFR expression. Mean EGFR methylation of 41 and 9% was observed in KRAS-mutated and -wt patients, respectively (P=0.05). Conversely, a high EGFR methylation was observed in BRAF-wt patients with compared with patients possessing the mutated gene (18 vs. 3%, respectively; P=0.07). EGFR methylation was significantly correlated with the OS rate [hazard ratio, 0.98; 95% confidence interval (CI), 0.96–1.00; P=0.019], but not PFS rate. In patients with a methylation rate <10 and >10%, the median OS rate was 7.5 months (95% CI, 4.4–9.4 months) and 12.0 months (95% CI, 8.7–13.9 months), respectively (P=0.034). In conclusion, the present study revealed a correlation between EGFR methylation and improved OS rate in patients treated with CTX-based chemotherapy. The presence of EGFR methylation is inversely correlated with BRAF and PIK3CA mutations, indicating that the prognostic value of gene methylation may be worth verifying in further studies.

Epidermal Growth Factor Receptor Expression in Spindle Cell Carcinomas of the Head and Neck

Spindle cell carcinoma (SpCC) is an uncommon head and neck squamous cell carcinoma (SCC) variant consisting of spindled and/or pleomorphic cells with epithelial differentiation. Epidermal growth factor receptor (EGFR) is expressed by >90 % of conventional SCC, and high level expression is associated with a poorer prognosis. Anti-EGFR therapies are commonly used to treat head and neck SCC. However, no studies have evaluated EGFR expression in SpCC. Cases of SpCC were retrieved from department files. The diagnosis required either a biphasic lesion with a squamous neoplastic component, or a purely spindle cell or pleomorphic tumor with immunohistochemical positivity for epithelial markers. EGFR immunohistochemistry was performed and was quantified in quartiles. Medical records were reviewed for clinical follow up information. EGFR was expressed in 21/30 (70 %) cases, including in the squamous component in 18/19 (95 %) and the spindle cell component in only 12/30 (40 %). Where the spindle cell component was positive, the intensity and distribution were lower than for the squamous component. Recurrent tumors were predominantly (80-90 %) of the spindle cell component, and had low (or absent) EGFR expression. Kaplan-Meier survival analysis showed no statistically significant differences in overall or disease free survival between the EGFR expressing and non-expressing groups (p = 0.414 and 0.19, respectively). SpCCs of the head and neck have a poor prognosis, and markedly reduced EGFR expression. EGFR-specific therapies may not be ideal for SpCC patients, which may lack EGFR expression, but further studies are needed.