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

Current status and future prospects of combined immunotherapy and epidermal growth factor receptor inhibitors in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a malignancy with a poor prognosis, and the majority of patients with HNSCC are diagnosed at later stages owing to its hidden anatomical location and atypical clinical symptoms. It is notably prone to recurrence and metastasis. The traditional treatments include surgery, radiotherapy, chemotherapy, and targeted therapy. Although multiple treatment strategies have been established, the prognosis remains poor because most patients develop resistance to traditional treatments. In recent years, epidermal growth factor receptor (EGFR) inhibitors and immune checkpoint inhibitors (ICIs) have been shown to provide clinical benefits to these patients. Based on the promising results of both anti-EGFR therapy and immunotherapy, as well as the biological rationale for combining immunotherapy with anti-EGFR drugs, numerous preclinical and ongoing or completed clinical trials have explored the use of their synergistic effects. This review summarizes the feasibility of combining immunotherapy with EGFR inhibitors for HNSCC treatment and analyses the relevant biomarkers. It also summarizes the strategies for clinical applications. We found that immunotherapy and EGFR inhibitor combination therapy showed promise in treating patients with HNSCC and exhibited safety with acceptable adverse events. This review may provide valuable insights for the future development of treatments and formulation of therapeutic strategies for HNSCC, as well as useful information for the future design of clinical trials.

Human Papilloma Virus Positive Oropharyngeal Squamous Cell Carcinoma and the Immune System: Pathogenesis, Immunotherapy and Future Perspectives

Oropharyngeal squamous cell carcinoma (OPSCC), a subset of head and neck squamous cell carcinoma (HNSCC), involves the palatine tonsils, soft palate, base of tongue, and uvula, with the ability to spread to adjacent subsites. Personalized treatment strategies for Human Papillomavirus-associated squamous cell carcinoma of the oropharynx (HPV+OPSCC) are yet to be established. In this article, we summarise our current understanding of the pathogenesis of HPV+OPSCC, the intrinsic role of the immune system, current ICI clinical trials, and the potential role of small molecule immunotherapy in HPV+OPSCC.

Randomized phase II study of preoperative afatinib in untreated head and neck cancers: predictive and pharmacodynamic biomarkers of activity

There is no strong and reliable predictive biomarker in head and neck squamous cell carcinoma (HNSCC) for EGFR inhibitors. We aimed to identify predictive and pharmacodynamic biomarkers of efficacy of afatinib, a pan-HER tyrosine kinase inhibitor, in a window-of-opportunity trial (NCT01415674). Multi-omics analyses were carried out on pre-treatment biopsy and surgical specimen for biological assessment of afatinib activity. Sixty-one treatment-naïve and operable HNSCC patients were randomised to afatinib 40 mg/day for 21-28 days versus no treatment. Afatinib produced a high rate of metabolic response. Responders had a higher expression of pERK1/2 (P = 0.02) and lower expressions of pHER4 (P = 0.03) and pRB1 (P = 0.002) in pre-treatment biopsy compared to non-responders. At the cellular level, responders displayed an enrichment of tumor-infiltrating B cells under afatinib (P = 0.02). At the molecular level, NF-kappa B signaling was over-represented among upregulated genes in non-responders (P < 0.001; FDR = 0.01). Although exploratory, phosphoproteomics-based biomarkers deserve further investigations as predictors of afatinib efficacy.

Prognostic and predictive biomarkers for anti-EGFR monoclonal antibody therapy in RAS wild-type metastatic colorectal cancer: a systematic review and meta-analysis

BACKGROUND

RAS mutations affect prognosis in patients with metastatic colorectal cancer (mCRC) and have been identified as strong negative predictive markers for anti-epidermal growth factor receptor monoclonal antibody (anti-EGFR mAb) therapy, but many tumors containing wild-type RAS genes still do not respond to these therapies. Some additional biomarkers may have prognostic or predictive roles, but conclusions remain controversial.

METHODS

We performed a meta-analysis and systematic review of randomized controlled trials comparing anti-EGFR mAb therapy with alternative therapy that investigated the prognostic and predictive impact of additional biomarkers in RAS wild-type (wt) mCRC patients. Hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) and odds ratios (ORs) for objective response rate (ORR) were calculated. The prognostic value of biomarkers was investigated by separately pooling HR and OR for different treatment groups in an individual study. The predictive value was assessed by pooling study interactions between treatment effects and biomarker subgroups.

RESULTS

Thirty publications reporting on eighteen trials were selected, including a total of 13,507 patients. In prognostic analysis, BRAF mutations were associated with poorer PFS [HRs = 3.76 (2.47-5.73) and 2.69 (1.82-3.98)] and OS [HRs = 2.66 (1.95-3.65) and 2.45 (1.55-3.88)] in both the experimental and control arms; low miR-31-3p expression appeared to have longer PFS and OS. In terms of predictive effect, a lack of response to anti-EGFR therapy was observed in patients with BRAF mutant tumors (Pinteraction < 0.01 for PFS). Patients with tumors with any mutation in the KRAS/NRAS/BRAF/PIK3CA gene also showed similar results compared with all wild-type tumors (Pinteraction for PFS, OS, and ORR were < 0.01, < 0.01 and 0.01, respectively). While low miR-31-3p expression could predict PFS (Pinteraction = 0.01) and OS (Pinteraction = 0.04) benefit. The prognostic and predictive value regarding PIK3CA mutations, PTEN mutations or deletions, EGFR, EREG/AREG, HER2, HER3, and HER4 expression remains uncertain.

CONCLUSIONS

In RAS wt mCRC patients receiving EGFR-targeted therapy, BRAF mutation is a powerful prognostic and therapy-predictive biomarker, with no effect found for PIK3CA mutation, PTEN mutation or deletion, but the combined biomarker KRAS/NRAS/BRAF/PIK3CA mutations predict resistance to anti-EGFR therapy. Low miR-31-3p expression may have positive prognostic and therapy predictive effects. Evidence on the prognostic and predictive roles of EGFR and its ligands, and HER2/3/4 is insufficient.

Unsupervised Hierarchical Clustering of Head and Neck Cancer Patients by Pre-Treatment Plasma Metabolomics Creates Prognostic Metabolic Subtypes

There is growing evidence that the metabolism is deeply intertwined with head and neck squamous cell carcinoma (HNSCC) progression and survival but little is known about circulating metabolite patterns and their clinical potential. We performed unsupervised hierarchical clustering of 209 HNSCC patients via pre-treatment plasma metabolomics to identify metabolic subtypes. We annotated the subtypes via pathway enrichment analysis and investigated their association with overall and progression-free survival. We stratified the survival analyses by smoking history. High-resolution metabolomics extracted 186 laboratory-confirmed metabolites. The optimal model created two patient clusters, of subtypes A and B, corresponding to 41% and 59% of the study population, respectively. Fatty acid biosynthesis, acetyl-CoA transport, arginine and proline, as well as the galactose metabolism pathways differentiated the subtypes. Relative to subtype B, subtype A patients experienced significantly worse overall and progression-free survival but only among ever-smokers. The estimated three-year overall survival was 61% for subtype A and 86% for subtype B; log-rank p = 0.001. The association with survival was independent of HPV status and other HNSCC risk factors (adjusted hazard ratio = 3.58, 95% CI: 1.46, 8.78). Our findings suggest that a non-invasive metabolomic biomarker would add crucial information to clinical risk stratification and raise translational research questions about testing such a biomarker in clinical trials.

Recent Developments in Combination Chemotherapy for Colorectal and Breast Cancers with Topoisomerase Inhibitors

DNA topoisomerases are important enzymes that stabilize DNA supercoiling and resolve entanglements. There are two main types of topoisomerases in all cells: type I, which causes single-stranded DNA breaks, and type II, which cuts double-stranded DNA. Topoisomerase activity is particularly increased in rapidly dividing cells, such as cancer cells. Topoisomerase inhibitors have been an effective chemotherapeutic option for the treatment of several cancers. In addition, combination cancer therapy with topoisomerase inhibitors may increase therapeutic efficacy and decrease resistance or side effects. Topoisomerase inhibitors are currently being used worldwide, including in the United States, and clinical trials on the combination of topoisomerase inhibitors with other drugs are currently underway. The primary objective of this review was to comprehensively analyze the current clinical landscape concerning the combined application of irinotecan, an extensively investigated type I topoisomerase inhibitor for colorectal cancer, and doxorubicin, an extensively researched type II topoisomerase inhibitor for breast cancer, while presenting a novel approach for cancer therapy.

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.

An Inflammatory Signature to Predict the Clinical Benefit of First-Line Cetuximab Plus Platinum-Based Chemotherapy in Recurrent/Metastatic Head and Neck Cancer

Epidermal growth factor receptor (EGFR) pathway has been shown to play a crucial role in several inflammatory conditions and host immune-inflammation status is related to tumor prognosis. This study aims to evaluate the prognostic significance of a four-gene inflammatory signature in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) patients treated with the EGFR inhibitor cetuximab plus chemotherapy. The inflammatory signature was assessed on 123 R/M HNSCC patients, enrolled in the multicenter trial B490 receiving first-line cetuximab plus platinum-based chemotherapy. The primary endpoint of the study was progression free survival (PFS), while secondary endpoints were overall survival (OS) and objective response rate (ORR). The patient population was subdivided into 3 groups according to the signature score groups. The four-genes-signature proved a significant prognostic value, resulting in a median PFS of 9.2 months in patients with high vs. 6.2 months for intermediate vs. 3.9 months for low values (p = 0.0016). The same findings were confirmed for OS, with median time of 18.4, 13.4, and 7.5 months for high, intermediate, and low values of the score, respectively (p = 0.0001). When ORR was considered, the signature was significantly higher in responders than in non-responders (p = 0.0092), reaching an area under the curve (AUC) of 0.65 (95% CI: 0.55–0.75). Our findings highlight the role of inflammation in the response to cetuximab and chemotherapy in R/M-HNSCC and may have translational implications for improving treatment selection.

Parathyroid hormone-related peptide and parathyroid hormone-related peptide receptor type 1 in locally advanced laryngeal cancer as prognostic indicators of relapse and survival

Background

Parathyroid hormone-related peptide (PTHrP) overexpression and poor patient outcome have been reported for many human tumors, but no studies are available in laryngeal cancer. Therefore, we studied the expression of PTHrP and its receptor, parathyroid hormone-related peptide receptor type 1 (PTH1R), in primary locally advanced laryngeal squamous cell carcinomas (LALSCC) also in relation to the clinical outcome of patients.

Methods

We conducted a retrospective exploratory study, using immunohistochemistry, on PTHrP, PTH1R and HER1 expressions in LALSCC of 66 patients treated with bio-radiotherapy with cetuximab.

Results

The expressions of PTHrP and PTH1R in LALSCC were associated with the degree of tumor differentiation (p = 0.01 and 0.04, respectively). Poorly differentiated tumors, with worse prognosis, expressed PTHrP at nuclear level and were PTH1R negative. PTHrP and PTH1R were expressed at cytoplasmic level in normal larynx epithelium and more differentiated laryngeal cancer cells, suggesting an autocrine/paracrine role of PTHrP in squamous cell differentiation of well differentiated tumors with good prognosis. Eighty-one percent HER1 positive tumors expressed PTHrP (p < 0.0001), mainly at nuclear level, consistent with the known up-regulation of PTHrP gene by HER1 signaling. In multivariable analyses, patients with PTHrP positive tumors had a higher relative risk of relapse (HR = 5.49; CI 95% = 1.62–22.24; p = 0.006) and survival (HR = 8.21; CI 95% = 1.19–105.00; p = 0.031) while those with PTH1R positive tumors showed a lower relative risk of relapse (HR = 0.18; CI 95% = 0.04–0.62; p = 0.002) and survival (HR = 0.18; CI 95% = 0.04–0.91; p = 0.029).

Conclusions

In LALSCC nuclear PTHrP and absence of PTH1R expressions could be useful in predicting response and/or resistance to cetuximab in combined therapies, contributing to an aggressive behavior of tumor cells downstream to HER1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09748-1.

Regression of EGFR positive established solid tumors in mice with the conditionally active T cell engager TAK-186

Background

Despite clinical success with T cell engagers (TCEs) targeting hematological malignancies, achieving a safe and efficacious dose in patients with solid tumors remains challenging. Due to potency, low levels of target antigen expression on normal tissues may not be tolerated. To overcome this, we engineered a novel conditionally active TCE design called COBRA (Conditional Bispecific Redirected Activation). Administered as prodrugs, COBRAs bind to cell surface antigens on both normal and tumor tissues but are preferentially activated within the tumor microenvironment.

Methods

A COBRA was engineered to target EGFR, TAK-186. The potency of precleaved TAK-186 relative to a non-cleavable control was assessed in vitro. Mice bearing established solid tumors expressing a range of EGFR levels were administered a single bolus of human T cells, and concurrently treated with TAK-186 and associated controls intravenously. We assessed the plasma and tumor exposure of intact and cleaved TAK-186.

Results

TAK-186 shows potent redirected T cell killing of antigen expressing tumor cells. In vivo efficacy studies demonstrate regressions of established solid tumors, dependent on intratumoral COBRA cleavage. Pharmacokinetic studies reveal TAK-186 is stable in circulation, but once activated is rapidly cleared due to loss of its albumin-binding half-life extension domain.

Conclusions

The studies shown support the advancement of TAK-186, and the pursuit of additional COBRA TCEs for the treatment of solid tumors.

Caveolin-1 and Sox-2 are predictive biomarkers of cetuximab response in head and neck cancer

The epidermal growth factor receptor (EGFR) inhibitor cetuximab is the only FDA-approved oncogene-targeting therapy for head and neck squamous cell carcinoma (HNSCC). Despite variable treatment response, no biomarkers exist to stratify patients for cetuximab therapy in HNSCC. Here, we applied unbiased hierarchical clustering to reverse-phase protein array molecular profiles from patient-derived xenograft (PDX) tumors and revealed 2 PDX clusters defined by protein networks associated with EGFR inhibitor resistance. In vivo validation revealed unbiased clustering to classify PDX tumors according to cetuximab response with 88% accuracy. Next, a support vector machine classifier algorithm identified a minimalist biomarker signature consisting of 8 proteins — caveolin-1, Sox-2, AXL, STING, Brd4, claudin-7, connexin-43, and fibronectin — with expression that strongly predicted cetuximab response in PDXs using either protein or mRNA. A combination of caveolin-1 and Sox-2 protein levels was sufficient to maintain high predictive accuracy, which we validated in tumor samples from patients with HNSCC with known clinical response to cetuximab. These results support further investigation into the combined use of caveolin-1 and Sox-2 as predictive biomarkers for cetuximab response in the clinic.

Long-term survivor of metastatic squamous-cell head and neck carcinoma with occult primary after cetuximab-based chemotherapy: A case report

BACKGROUND

Cancer of unknown primary (CUP) is a histological proven malignant tumor whose origin cannot be detected despite careful examination. Most cervical lymph node metastases in CUP (80%) will originate from head and neck sites, and 15% show infiltration of squamous carcinoma cells. The survival rates of CUP are poor: The 5-year-survival rate ranges from 10% to 15%. First-line treatment recommendation for advanced, inoperable squamous cell carcinoma of head/neck (HNSCC) was cetuximab plus platinum-fluorouracil chemotherapy until recently, when checkpoint inhibitors proved clinically beneficial therapies.

CASE SUMMARY

Here, we report a case of a 42-year-old female patient with cervical and abdominal lymph node and distant bone metastases of an occult primary of the head and neck (squamous cell carcinoma, human papillomavirus positive). The cancer was diagnosed during pregnancy 10 years ago, and after giving birth, the patient was treated with cetuximab plus platinum-fluorouracil chemotherapy achieving complete remission (CR). CR lasted 26 mo when new metastases (abdominal lymph node, lumbar vertebral body) emerged. Both manifestations were irradiated. From then on, the patient has not received any further treatment, and her disease has remained controlled. Ten years after the initial cancer diagnosis, the patient is still alive and in good health, representing an exceptional case of HNSCC.

CONCLUSION

This case illustrates the exceptional clinical course and benefits of combined therapy approaches in advanced metastatic HNSCC with occult primary.

Prognostic impact and potential predictive role of baseline circulating tumor cells in locally advanced head and neck squamous cell carcinoma

OBJECTIVES

The prognostic impact of circulating tumor cells (CTCs) or circulating tumor microemboli (CTM) in locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is yet to be determined, with conflicting results in previous trials. The role of induction chemotherapy (ICT) in the management of LA-HNSCC is controversial with no predictive biomarkers to guide treatment strategy in this scenario. The aim of this trial is to determine the prognostic impact of CTCs and CTM, their biomarkers expression by immunocytochemistry (ICC), and its potential role as predictors of ICT benefit in LA-HNSCC.

MATERIALS AND METHODS

Prospective study, with newly diagnosed stage III/IV non-metastatic LA-HNSCC patients treated with curative intent. Blood samples analyzed for CTCs and CTM before treatment using the ISET method.

RESULTS

A total of 83 patients were included. CTCs counts were an independent prognostic factor for overall survival (OS; HR: 1.17; 95 %CI: 1.05-1.31; p = 0.005) and progression free survival (PFS; HR:1.14; 95 %CI: 1.03-1.26; p = 0.007). Using the Lausen and Schumacher technique, 2.8 CTCs/mL for OS and 3.8 CTCs/mL for PFS were defined as the best cut-offs. CTM were detected in 27.7% of patients, correlating with worse PFS (HR = 2.70; IC95%: 1.30-5.58; p = 0.007). MRP-7 expression in CTM correlated with worse OS (HR = 3.49; 95 %CI: 1.01-12.04; p = 0.047) and PFS (HR = 3.62; 95 %CI: 1.08-12.13; p = 0.037). CTCs counts were predictive of complete response to treatment (OR = 0.74; 95 %CI: 0.58-0.95; p = 0.022) and high counts (cut-off 3.8/mL) and CTM were potential predictors of ICT benefit.

CONCLUSION

CTCs/CTM had significant prognostic impact and potential role as predictors of ICT benefit in LA-HNSCC.

Precision Medicine Gains Momentum: Novel 3D Models and Stem Cell-Based Approaches in Head and Neck Cancer

Despite the current progress in the development of new concepts of precision medicine for head and neck squamous cell carcinoma (HNSCC), in particular targeted therapies and immune checkpoint inhibition (CPI), overall survival rates have not improved during the last decades. This is, on the one hand, caused by the fact that a significant number of patients presents with late stage disease at the time of diagnosis, on the other hand HNSCC frequently develop therapeutic resistance. Distinct intratumoral and intertumoral heterogeneity is one of the strongest features in HNSCC and has hindered both the identification of specific biomarkers and the establishment of targeted therapies for this disease so far. To date, there is a paucity of reliable preclinical models, particularly those that can predict responses to immune CPI, as these models require an intact tumor microenvironment (TME). The "ideal" preclinical cancer model is supposed to take both the TME as well as tumor heterogeneity into account. Although HNSCC patients are frequently studied in clinical trials, there is a lack of reliable prognostic biomarkers allowing a better stratification of individuals who might benefit from new concepts of targeted or immunotherapeutic strategies. Emerging evidence indicates that cancer stem cells (CSCs) are highly tumorigenic. Through the process of stemness, epithelial cells acquire an invasive phenotype contributing to metastasis and recurrence. Specific markers for CSC such as CD133 and CD44 expression and ALDH activity help to identify CSC in HNSCC. For the majority of patients, allocation of treatment regimens is simply based on histological diagnosis and on tumor location and disease staging (clinical risk assessments) rather than on specific or individual tumor biology. Hence there is an urgent need for tools to stratify HNSCC patients and pave the way for personalized therapeutic options. This work reviews the current literature on novel approaches in implementing three-dimensional (3D) HNSCC in vitro and in vivo tumor models in the clinical daily routine. Stem-cell based assays will be particularly discussed. Those models are highly anticipated to serve as a preclinical prediction platform for the evaluation of stable biomarkers and for therapeutic efficacy testing.

Cetuximab combined with paclitaxel or paclitaxel alone for patients with recurrent or metastatic head and neck squamous cell carcinoma progressing after EXTREME

BACKGROUND

Prognosis of recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) remains poor. The addition of cetuximab, to platinum and fluorouracil chemotherapy (EXTREME regimen) has been shown to improve patients' outcomes in first-line settings.

METHODS

We conducted a retrospective, multicenter study, including HNSCC that progressed after a first line of platinum-based chemotherapy and cetuximab, treated either by paclitaxel + cetuximab (PC) or paclitaxel alone (P), between January 2010 and April 2018. The end points were overall survival (OS), progression-free survival (PFS), and overall response rates (ORR). Patients were matched according to their propensity scores, estimated with a logistic regression model. The secondary objectives were to study the safety profile and to look for prognostic and predictive factors of effectiveness.

RESULTS

Of the 340 identified patients, 262 were included in the analysis, 165 received PC, and 97 received P. In unmatched population, ORR was 16.4% with PC and 6.2% for P. Median PFS was 2.9 months [95% Confidence Interval 2.7-3.0] for PC versus 2.5 months [2.2-2.7] for P, hazard ratio (HR) = 0.770 [0.596-0.996]. Median OS was 5.5 months [4.4-6.9] for PC versus 4.2 months [3.4-4.8] for P, HR = 0.774 [0.590-1.015]. In multivariate analysis, PC was associated with better PFS and OS. These results were consistent in matched-paired population. Previous cetuximab maintenance for more than 3 months was predictive of better OS with PC.

CONCLUSION

Although the continuation of cetuximab in combination with paclitaxel after EXTREME provides moderate benefit, it could be an interesting option for selected patients.

Targeting BRAF and RAS in Colorectal Cancer

Simple Summary

In colorectal cancer, mutations of the KRAS and BRAF genes are quite common and can contribute to the activation of cell signaling pathways that lead to cell proliferation and differentiation. These processes promote cancer growth, and in some cases, they may cause cells to develop resistance to certain types of treatment, notably EGFR inhibitors. We summarize recent knowledge regarding the effects of KRAS and BRAF mutations in the setting of colorectal cancer and discuss the new therapies under development.

Abstract

Colorectal cancer (CRC) is still one of the most frequent forms of cancer in the world in terms of incidence. Around 40% of CRC patients carry a mutation of the Kirsten rat sarcoma (KRAS) gene, while 10% have a mutation in the B-Raf proto-oncogene serine/threonine kinase (BRAF) gene. These mutations are responsible for dysregulation of the mitogen-associated protein kinase (MAPK) pathway, leading to the proliferation, differentiation, angiogenesis, and resistance to apoptosis of cells. Activation of the MAPK pathway results in adaptive therapeutic resistance, rendering EGFR inhibitors ineffective. This review aims to highlight the recent findings that have improved our understanding of KRAS and BRAF mutations in colorectal cancer and to describe new targeted therapies, used alone or in combination.

Predictive Value of EGFR-PI3K-AKT-mTOR-Pathway Inhibitor Biomarkers for Head and Neck Squamous Cell Carcinoma: A Systematic Review

BACKGROUND

Understanding molecular pathogenesis of head and neck squamous cell carcinomas (HNSCC) has considerably improved in the last decades. As a result, novel therapeutic strategies have evolved, amongst which are epidermal growth factor receptor (EGFR)-targeted therapies. With the exception of cetuximab, targeted therapies for HNSCC have not yet been introduced into clinical practice. One important aspect of new treatment regimes in clinical practice is presence of robust biomarkers predictive for therapy response.

METHODS

We performed a systematic search in PubMed, Embase and the Cochrane library. Articles were included if they investigated a biomarker for targeted therapy in the EGFR-PI3K-AKT-mTOR-pathway.

RESULTS

Of 83 included articles, 52 were preclinical and 33 were clinical studies (two studies contained both a preclinical and a clinical part). We classified EGFR pathway inhibitor types and investigated the type of biomarker (biomarker on epigenetic, DNA, mRNA or protein level).

CONCLUSION

Several EGFR-PI3K-AKT-mTOR-pathway inhibitor biomarkers have been researched for HNSCC but few of the investigated biomarkers have been adequately confirmed in clinical trials. A more systematic approach is needed to discover proper biomarkers as stratifying patients is essential to prevent unnecessary costs and side effects.

Objective Quantitation of EGFR Protein Levels using Quantitative Dot Blot Method for the Prognosis of Gastric Cancer Patients

Purpose

An underlying factor for the failure of several clinical trials of anti-epidermal growth factor receptor (EGFR) therapies is the lack of an effective method to identify patients who overexpress EGFR protein. The quantitative dot blot method (QDB) was used to measure EGFR protein levels objectively, absolutely, and quantitatively. Its feasibility was evaluated for the prognosis of overall survival (OS) of patients with gastric cancer.

Materials and Methods

Slices of 2×5 μm from formalin-fixed paraffin-embedded gastric cancer specimens were used to extract total tissue lysates for QDB measurement. Absolutely quantitated EGFR protein levels were used for the Kaplan-Meier OS analysis.

Results

EGFR protein levels ranged from 0 to 772.6 pmol/g (n=246) for all gastric cancer patients. A poor correlation was observed between quantitated EGFR levels and immunohistochemistry scores with ρ=0.024 and P=0.717 in Spearman's correlation analysis. EGFR was identified as an independent negative prognostic biomarker for gastric cancer patients only through absolute quantitation, with a hazard ratio of 1.92 (95% confidence interval, 1.05–3.53; P=0.034) in multivariate Cox regression OS analysis. A cutoff of 208 pmol/g was proposed to stratify patients with a 3-year survival probability of 44% for patients with EGFR levels above the cutoff versus 68% for those below the cutoff based on Kaplan-Meier OS analysis (log rank test, P=0.002).

Conclusions

A QDB-based assay was developed for gastric cancer specimens to measure EGFR protein levels absolutely, quantitatively, and objectively. This assay should facilitate clinical trials aimed at evaluation of anti-EGFR therapies retrospectively and prospectively for gastric cancer.

Comparative efficacy and safety of radiotherapy/cetuximab versus radiotherapy/chemotherapy for locally advanced head and neck squamous cell carcinoma patients: a systematic review of published, primarily non-randomized, data

Background:

Cetuximab (CTX) has been approved to be administered concurrently with radiotherapy (RT) to treat locally advanced head and neck squamous cell carcinoma (HNSCC). The aim of this study was to assess the efficacy and safety of concurrent CTX with RT (ExRT).

Method:

The PubMed, Cochrane Library, EMBASE databases were systematically searched to find relevant articles. The combined hazard ratio (HR), risk ratio (RR) and 95% confidence interval were calculated to assess the efficacy and safety of ExRT in contrast to concurrent platinum-based chemotherapy with RT (ChRT).

Results:

In total, 32 articles with 4556 patients were included. The pooled HRs indicated that ExRT achieved an unfavorable overall survival (HR: 1.86, p < 0.0001), disease-specific survival (HR: 2.58, p = 0.002), locoregional control (HR: 1.94, p < 0.00001), and progression-free survival (HR: 2.04, p = 0.003) compared with ChRT for locally advanced HNSCC patients. In human papillomavirus-positive patient subgroups, ExRT showed inferior disease-specific survival (HR: 2.55, p = 0.009) and locoregional control (HR: 2.27, p < 0.0001) in contrast to ChRT. Additionally, ExRT increased the occurrence of mucositis (RR: 1.17, p < 0.005), skin toxicity (RR: 6.26, p < 0.00001), and infection (RR: 2.27, p = 0.04) compared with non-CTX groups (ChRT and RT), and was associated with lower incidence of anemia (RR: 0.35, p = 0.009), leukocytopenia (RR: 0.17, p < 0.0001), neutropenia (RR: 0.06, p < 0.0001), nausea/vomiting (RR: 0.23, p < 0.0001), and renal toxicity (RR: 0.14, p = 0.007).

Conclusion:

ChRT should remain the standard treatment for locally advanced HNSCC patients. ExRT was recognized as an effective alternative treatment for locally advanced HNSCC patients who experienced unbearable toxicities caused by non-CTX treatments.

The Latest Battles Between EGFR Monoclonal Antibodies and Resistant Tumor Cells

Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor involved in homeostatic regulation of normal cells and carcinogenesis of epithelial malignancies. With rapid development of the precision medicine era, a series of new therapies targeting EGFR are underway. Four EGFR monoclonal antibody drugs (cetuximab, panitumumab, nimotuzumab, and necitumumab) are already on the market, and a dozen other EGFR monoclonal antibodies are in clinical trials. Here, we comprehensively review the newly identified biological properties and anti-tumor mechanisms of EGFR monoclonal antibodies. We summarize recently completed and ongoing clinical trials of the classic and new EGFR monoclonal antibodies. More importantly, according to our new standard, we re-classify the complex evolving tumor cell resistance mechanisms, including those involving exosomes, non-coding RNA and the tumor microenvironment, against EGFR monoclonal antibodies. Finally, we analyzed the limitations of EGFR monoclonal antibody therapy, and discussed the current strategies overcoming EGFR related drug resistance. This review will help us better understand the latest battles between EGFR monoclonal antibodies and resistant tumor cells, and the future directions to develop anti-tumor EGFR monoclonal antibodies with durable effects.

Cetuximab-induced natural killer cell cytotoxicity in head and neck squamous cell carcinoma cell lines: investigation of the role of cetuximab sensitivity and HPV status

Background

The epidermal growth factor receptor (EGFR) is overexpressed by 80–90% of squamous cell carcinoma of head and neck (HNSCC). In addition to inhibiting EGFR signal transduction, cetuximab, a monoclonal antibody targeting EGFR can also bind to fragment crystallisable domain of immunoglobulins G1 present on natural killer (NK), causing antibody-dependent cellular cytotoxicity (ADCC). However, presence of cetuximab resistance limits effective clinical management of HNSCC.

Methods

In this study, differences in induction of ADCC were investigated in a panel of ten HNSCC cell lines. Tumour cells were co-cultured with NK cells and monitored using the xCELLigence RTCA.

Results

While ADCC was not influenced by HPV status, hypoxia and cetuximab resistance did affect ADCC differentially. Intrinsic cetuximab-resistant cell lines showed an increased ADCC induction, whereas exposure to hypoxia reduced ADCC. Baseline EGFR expression was not correlated with ADCC. In contrast, EGFR internalisation following cetuximab treatment was positively correlated with ADCC.

Conclusion

These findings support the possibility that resistance against cetuximab can be overcome by NK cell-based immune reactions. As such, it provides an incentive to combine cetuximab with immunotherapeutic approaches, thereby possibly enhancing the anti-tumoural immune responses and achieving greater clinical effectiveness of EGFR-targeting agents.

Phase I Study of Ficlatuzumab and Cetuximab in Cetuximab-Resistant, Recurrent/Metastatic Head and Neck Cancer

Cetuximab, an anti-EGFR monoclonal antibody (mAb), is approved for advanced head and neck squamous cell carcinoma (HNSCC) but benefits a minority. An established tumor-intrinsic resistance mechanism is cross-talk between the EGFR and hepatocyte growth factor (HGF)/cMet pathways. Dual pathway inhibition may overcome cetuximab resistance. This Phase I study evaluated the combination of cetuximab and ficlatuzumab, an anti-HGF mAb, in patients with recurrent/metastatic HNSCC. The primary objective was to establish the recommended Phase II dose (RP2D). Secondary objectives included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Mechanistic tumor-intrinsic and immune biomarkers were explored. Thirteen patients enrolled with no dose-limiting toxicities observed at any dose tier. Three evaluable patients were treated at Tier 1 and nine at Tier 2, which was determined to be the RP2D (cetuximab 500 mg/m² and ficlatuzumab 20 mg/kg every 2 weeks). Median PFS and OS were 5.4 (90% CI = 1.9–11.4) and 8.9 (90% CI = 2.7–15.2) months, respectively, with a confirmed ORR of 2 of 12 (17%; 90% CI = 6–40%). High circulating soluble cMet levels correlated with poor survival. An increase in peripheral T cells, particularly the CD8⁺ subset, was associated with treatment response whereas progression was associated with expansion of a distinct myeloid population. This well-tolerated combination demonstrated promising activity in cetuximab-resistant, advanced HNSCC.

The emergence of long-term survivors in recurrent and metastatic squamous cell head and neck cancer

PURPOSE OF REVIEW

The systemic therapies available in recurrent and metastatic head and neck squamous cell carcinoma to date are palliative-intent treatments in most cases. However, a small subgroup of patients derives unconventional benefit and become long-term survivors, achieving cure in some cases. This review focusses on this group of patients, discusses recent literature and suggests plausible molecular hypothesis.

RECENT FINDINGS

Human papillomavirus-related disease is known to confer a better prognosis in metastatic patients, probably because of its greater sensitivity to systemic therapies. This group of patients seems to have a greater immune activation, which could partly explain this fact. Moreover, the use of antiepidermal growth factor receptor therapies in the metastatic setting has doubled the prevalence of long-term survivors. One of the most plausible explanations is the immune-modulatory effect of cetuximab mediated by antibody-dependent cell-mediated cytotoxicity.These facts, along with the recent encouraging results of checkpoint inhibitors in this disease, give hope that these therapies will not only improve survival but also increase the prevalence of long-term survivors.

SUMMARY

Long-term survivors merit our utmost attention as an in-depth study of these patients could help us to better understand the tumour biology and allow us to develop robust biomarkers and effective targeted therapies, which could in turn lead to a true paradigm shift.

Molecular genetics of head and neck squamous cell carcinoma

PURPOSE OF REVIEW

The aim of this review is to summarize the current knowledge on the genomic characterization of squamous cell carcinomas of the head and neck (HNSCC) and discusses how these abnormalities could be incorporated into a therapeutic approach.

RECENT FINDINGS

Tobacco and HPV infection, the two main risk factors of HNSCC, allow the definition of two groups with distinct anatomoclinical and genetic features. As tobacco and HPV infection are not exclusive, exposure to both risk factors is associated with an intermediate prognostic. HPV-positive, nontobacco-related HNSCCs are associated with a better prognosis, a rather more simple genomic profile, frequent activating mutations of genes involved in pi3kinase pathway, and the very low incidence of mutations of tumor suppressor genes. HPV-negative, tobacco-related HNSCC are genetically more complex. HPV-negative HNSCC are characterized by almost mandatory inactivating mutations/deletions of tumor suppressor genes (especially TP53 and CDKN2A) and the occurrence, though less frequent, of activating mutations or amplifications of some oncogenes that encode for cell cycle proteins or receptors with tyrosine kinase activity. Despite many efforts to improve therapeutic targeting in RM HNSCC, Cetuximab, a monoclonal antibody targeting REGF, remains the sole approved targeted treatment in RM HNSCC.

SUMMARY

Despite the increasingly precise genomic characterization of HNSCCs, precision medicine is struggling to find its place in the management of HNSCCs. Inclusion of enriched populations in dedicated trials is likely to help implement precision medicine in the management of HNSCCs.

EGFR Protein Expression in KRAS Wild-Type Metastatic Colorectal Cancer Is Another Negative Predictive Factor of the Cetuximab Therapy

The selection of colorectal cancer patients for anti-epidermal growth factor receptor (EGFR) antibody therapy is based on the determination of their RAS mutation status—a strongly negative predictive factor—since the protein target, EGFR, is not a reliable predictor of therapeutic response. In this study, we revisited the EGFR protein issue using a cohort of 90 patients with KRAS exon2 wild-type colorectal cancer who have been treated with cetuximab therapy. Twenty-nine of these patients had metastatic tissue available for analysis. The level of EGFR protein expression in the patients was determined by immunohistochemistry and evaluated by H-score (HS) methodology. Progression-free survival (PFS) and overall survival (OS) of the patients were determined according to the EGFR-HS ranges of both the primary and metastatic tissues using Kaplan–Meyer statistics. In the case of primary tumors, EGFR scores lower than HS = 200 were associated with significantly longer OS. In the case of metastatic tissues, all levels lower than the EGFR-HS range chosen were associated with significantly longer OS. These results are explained by the fact that metastatic tissues rarely maintained the expression levels of the primary tumors. On the other hand, high EGFR expression levels in either primary tumors or metastatic tissues were associated with multiple metastatic disease. This suggests a negative prognostic role of EGFR expression. However, in a multivariate analysis, one-sidedness remained a strong independent predictive factor of survival. Previous studies demonstrated that the EGFR expression level depends on sidedness. Therefore, a subgroup analysis of the left- and right-sided cases was performed on both primary and metastatic tissues. In the case of metastic tissues, an analysis confirmed a better OS in low EGFR protein-expressing cases than in high EGFR protein-expressing cases. Collectively, these data suggest that EGFR protein expression is another negative predictive factor of the efficacy of cetuximab therapy of KRAS exon2 wild-type colorectal cancer.

Novel EGFR ectodomain mutations associated with ligand-independent activation and cetuximab resistance in head and neck cancer

Epidermal growth factor receptor (EGFR) is a pro-tumorigenic receptor tyrosine kinase that facilitates growth for cancer cells that overexpress the receptor. Monoclonal anti-EGFR antibody Cetuximab (CTX) provides significant clinical benefit in patients with head and neck squamous cell carcinoma (HNSCC). Missense mutations in the ectodomain (ECD) of EGFR can be acquired under CTX treatment and mimic the effect of large deletions on spontaneous untethering and activation of the receptor. Little is known about the contribution of EGFR ECD mutations to EGFR activation and CTX resistance in HNSCC. We identified two concurrent non-synonymous missense mutations (G33S and N56K) mapping to domain I in or near the EGF binding pocket of the EGFR ECD in patient-derived HNSCC cells that were selected for CTX resistance through repeated exposure to the agent in an effort to mimic what may occur clinically. Structural modeling predicted that the G33S and N56K mutants would restrict adoption of a fully closed (tethered) and inactive EGFR conformation while not permitting association of EGFR with the EGF ligand or CTX. Binding studies confirmed that the mutant, untethered receptor displayed reduced affinity for both EGF and CTX but demonstrated sustained activation and presence at the cell surface with diminished internalization and sorting for endosomal degradation, leading to persistent downstream AKT signaling. Our results demonstrate that HNSCC cells can select for EGFR ECD mutations under CTX exposure that converge to trap the receptor in an open, ligand-independent, constitutively activated state. These mutants impede the receptor’s competence to bind CTX possibly explaining certain cases of CTX treatment-induced or de novo resistance to CTX.

Interleukin 6 is increased in preclinical HNSCC models of acquired cetuximab resistance, but is not required for maintenance of resistance

The epidermal growth factor receptor inhibitor cetuximab is the only oncogene-targeted agent that has been FDA approved for the treatment of head and neck squamous cell carcinoma (HNSCC). Currently, there are no biomarkers used in the clinic to predict which HNSCC tumors will respond to cetuximab, and even in tumors that regress with treatment, acquired resistance occurs in the majority of cases. Though a number of mechanisms of acquired resistance to cetuximab have been identified in preclinical studies, no therapies targeting these resistance pathways have yet been effectively translated into the clinic. To address this unmet need, we examined the role of the cytokine interleukin 6 (IL-6) in acquired cetuximab resistance in preclinical models of HNSCC. We found that IL-6 secretion was increased in PE/CA-PJ49 cells that had acquired resistance to cetuximab compared to the parental cells from which they were derived. However, addition of exogenous IL-6 to parental cells did not promote cetuximab resistance, and inhibition of the IL-6 pathway did not restore cetuximab sensitivity in the cetuximab-resistant cells. Further examination of the IL-6 pathway revealed that expression of IL6R, which encodes a component of the IL-6 receptor, was decreased in cetuximab-resistant cells compared to parental cells, and that treatment of the cetuximab-resistant cells with exogenous IL-6 did not induce phosphorylation of signal transducer and activator of transcription 3, suggesting that the IL-6 pathway was functionally impaired in the cetuximab-resistant cells. These findings demonstrate that, even if IL-6 is increased in the context of cetuximab resistance, it is not necessarily required for maintenance of the resistant phenotype, and that targeting the IL-6 pathway may not restore sensitivity to cetuximab in cetuximab-refractory HNSCC.

Identification of Target Associations for Polypharmacology from Analysis of Crystallographic Ligands of the Protein Data Bank

The design of a chemical entity that potently and selectively binds to a biological target of therapeutic relevance has dominated the scene of drug discovery so far. However, recent findings suggest that multitarget ligands may be endowed with superior efficacy and be less prone to drug resistance. The Protein Data Bank (PDB) provides experimentally validated structural information about targets and bound ligands. Therefore, it represents a valuable source of information to help identifying active sites, understanding pharmacophore requirements, designing novel ligands, and inferring structure-activity relationships. In this study, we performed a large-scale analysis of the PDB by integrating different ligand-based and structure-based approaches, with the aim of identifying promising target associations for polypharmacology based on reported crystal structure information. First, the 2D and 3D similarity profiles of the crystallographic ligands were evaluated using different ligand-based methods. Then, activity data of pairs of similar ligands binding to different targets were inspected by comparing structural information with bioactivity annotations reported in the ChEMBL, BindingDB, BindingMOAD, and PDBbind databases. Afterward, extensive docking screenings of ligands in the identified cross-targets were made in order to validate and refine the ligand-based results. Finally, the therapeutic relevance of the identified target combinations for polypharmacology was evaluated from comparison with information on therapeutic targets reported in the Therapeutic Target Database (TTD). The results led to the identification of several target associations with high therapeutic potential for polypharmacology.

Cisplatin and 5-fluorouracil with or without epidermal growth factor receptor inhibition panitumumab for patients with non-resectable, advanced or metastatic oesophageal squamous cell cancer: a prospective, open-label, randomised phase III AIO/EORTC trial (POWER)

BACKGROUND

Palliative chemotherapy of advanced oesophageal squamous cell cancer (ESCC) consists of cisplatin/5-fluorouracil (CF) to target epidermal growth factor receptor (EGFR) with panitumumab (P); chemotherapy enhanced overall survival (OS) in advanced colorectal or squamous cell head and neck cancers. With prospective serum and tumour biomarkers, we tested if P added to CF (CFP) improved OS in advanced ESCC.

PATIENTS AND METHODS

Eligible patients with confirmed ESCC that was not curatively resectable or did not qualify for definitive radiochemotherapy, were randomised 1 : 1 to receive CF [cisplatin (C) 100 mg/m² i.v., day 1; 5-fluorouracil (F) 1000 mg/m² i.v., days 1-4] or CF plus P (9 mg/kg, i.v., day 1, each q3-week cycle) until progressive disease or unacceptable toxicity. Safety was reviewed by the Data Safety Monitoring Board after 40, 70 and 100 patients who completed at least one cycle. After 53 enrolled patients, cisplatin was reduced from 100 mg/m² to 80 mg/m².

RESULTS

The trial was stopped early based on interim efficacy results triggered by the third safety analysis: median OS (mOS) favoured CF over CFP, regardless of cisplatin dose [hazard ratio (HR) 1.77, 95% confidence interval (CI) 1.06-2.98; P = 0.028]. In the final analysis, mOS was 10.2 versus 9.4 months for CF versus CFP, respectively (HR 1.17, 95% CI 0.79-1.75; P = 0.43). One hundred (70.4%) of 142 patients in the safety population died, 51 (51.0%) with CFP. Most deaths were related to disease progression [44/49 (90%) deaths in CF versus 34/51 (67%) deaths in CFP]; objective responses [27/73 (37.0%)] were identical. The most common serious adverse events were kidney injury [3 (4.3%) versus 7 (9.7%)], general health deterioration [5 (7.1%) versus 5 (6.9%)] and dysphagia [4 (5.7%) versus 4 (5.6%)] in CF versus CFP, respectively. There were three (4.3%) and 17 (23.6%) common terminology criteria for adverse events (CTCAE) grade 5 events in CF versus CFP, respectively. Low soluble (s)EGFR levels were associated with better progression-free survival; sEGFR was induced under CFP.

CONCLUSION

EGFR inhibition added to CF did not improve survival in unselected advanced ESCC patients. The results support further liquid biopsy studies.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01627379) and EudraCT (2010-020606-15).

Management of recurrent and metastatic oral cavity cancer: Raising the bar a step higher

In recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M-SCCHN), the armamentarium of systemic anti-cancer modalities continues to grow in parallel with innovations in and better integration of local approaches. The backbone of cytotoxic chemotherapy remains cisplatin with 5-fluorouracil or a taxane. In contrast to cisplatin, the tumoricidal activity of carboplatin monotherapy is debatable. Adding the epidermal growth factor receptor (EGFR) inhibitor cetuximab to a platinum/5-fluorouracil doublet (the so-called EXTREME regimen) produced a statistically but also clinically significant improvement of survival and became thus the standard first-line palliative treatment in adequately fit patients. Interestingly, three large randomized trials (EXTREME, SPECTRUM, and ZALUTE) evaluating different anti-EGFR monoclonal antibodies (cetuximab, panitumumab, and zalutumumab, respectively) demonstrated preferential anti-tumour efficacy in patients with primary cancer in the oral cavity. Modern immunotherapy with immunomodulating antibodies, dubbed immune checkpoint inhibitors, such as anti-programmed cell death protein-1 (anti-PD-1) inhibitors nivolumab and pembrolizumab, showed unprecedented activity in one first-line (KEYNOTE-048) and several second-line trials (CheckMate-141, KEYNOTE-012, KEYNOTE-055, and KEYNOTE-040). In a minority of also heavily-pretreated patients, these agents generate long-lasting responses without the typical chemotherapy-related toxicity, however, at a price of a low overall response rate, rare but potentially life-threatening immune-related adverse events, the risk of hyperprogression, and high costs. In oligometastatic disease, emerging data indicate long-term benefit with locally ablative techniques including metastasectomy and stereotactic radiotherapy of pulmonary but also hepatic and other distant lesions. In the frame of highly-individualized cancer care, a particularly intriguing approach is a combination of systemic and local therapies.

Mutational spectrum of tobacco associated oral squamous carcinoma and its therapeutic significance

Oral squamous cell cancer (OSCC) is a common malignancy attributed to use of chewing smokeless tobacco and smoking. Most of the targeted strategies are based on EGFR expression and mutation; however, none of them has shown significant improvement in survival and response rates. We carried out this study to evaluate mutational profile of tobacco associated oral carcinoma with special emphasis on EGFR and its downstream events.

PATIENTS AND METHODS

A total of 46 histologically proven cases were recruited between January 2017 and January 2019. Apart from detailed clinical and histological studies, the paraffin-embedded tissue was submitted for expression of 50 genes using Next Generation Sequencing using Ion Ampliseq Cancer Hotspot Panel v2.

RESULTS

The mean age of patients was 47.8 ± 10.9 years. Majority had tumors on buccal mucosa (24) and tongue (13). Nineteen of these tumors were larger than 4 cm, and 5 had adjacent site involvement. Thirty one were node positive. TP53 mutations were commonest seen in 19 followed by CDKN2A in 11, HRAS in 8, PIK3CA in 3, SMARCB1 in 2, and KIT, EGFR, BRAF, STK11, ABL1, RB1 in one case each. Concomitant TP53 mutation was identified with other mutations like CDKN2A, HRAS, KIT, PIK3CA, STK11, SMARCB1, ABL1, and RB1 making tobacco-associated OSCC as a heterogeneous mutational tumor with multiple events. A patient with TP53 mutations has poor disease free survival (47.4 vs 63% p = 0.17); however, this was not statistically significant.

CONCLUSION

The study shows a heterogeneous mutational spectrum with multiple mutational events in OSCC. The low EGFR mutation rates and higher mutations in EGFR downstream pathways including that in TP53 and HRAS suggest that anti EGFR strategies may not succeed in these tumors and newer agents and therapeutic combinations need to be tried.

Targeting the EGFR and Immune Pathways in Squamous Cell Carcinoma of the Head and Neck (SCCHN): Forging a New Alliance

Despite the recent approval of immune-modulatory agents, EGFR inhibition continues to be a cornerstone in the management of squamous cell carcinoma of the head and neck (SCCHN) namely in combination with radiotherapy in the treatment of locoregionally advanced disease as well as in platinum-sensitive recurrent or metastatic disease in the first-line setting. Importantly, recent evidence has emerged supporting also an immune-modulatory effect of EGFR inhibition, and interest has now focused on utilizing these effects in the current treatment approaches for SCCHN. In this report, we review the rationale and evidence supporting the forging of this new alliance in optimizing the treatment of SCCHN.

Cost-effectiveness of Molecular Profile Patient Selection for First-line Treatment of Recurrent/Metastatic Head and Neck Cancer

PURPOSE

Patients with recurrent and/or metastatic head and neck squamous cell cancer are offered platinum-based chemotherapy plus cetuximab; however, this strategy is not cost-effective. We evaluated the cost-effectiveness of a hypothetical predictive molecular test to identify and treat only patients potentially responsive to cetuximab (C) added to platinum-fluorouracil (PF) (PF + C POS) versus the administration of PF + C to all patients (PF + C ALL).

METHODS

A Markov model has been developed to estimate health outcomes (quality-adjusted life years [QALYs]; life years [LYs]) and costs of the 2 strategies on a time horizon of 3 years from the Italian health care perspective. For the response to treatment, a definition, including partial or complete response, has been applied. In the base-case scenario, molecular test sensitivity, specificity, and cost have been assumed equal to 85%, 70%, and €4000, respectively.

FINDINGS

The model estimated 0.5285 QALYs (0.9245 LYs) and 0.5666 QALYs (0.9949 LYs) for PF + C POS and PF + C ALL, respectively. The incremental cost-utility ratio of PF + C ALL versus PF + C POS was €112,462/QALY, suggesting the administration of PF + C only to patients who would be responsive to it.

IMPLICATIONS

The use of cetuximab with chemotherapy could be a cost-effective choice in first-line recurrent and/or metastatic head and neck squamous cell cancer if based on a molecular selection able to identify which patients will achieve partial or complete response to the treatment. The developed model may be usefully applied to new emerging treatments, such as immunotherapeutic agents in the same setting.

Clinical utility of a protein-based oncopanel in patients with end-stage head and neck cancer

Aim: In a prospective clinical initiative, we selected heavily pretreated head and neck carcinoma patients and assessed the clinical utility of a protein-based oncopanel for identification of potential targetable markers. Patients & methods: Tumor samples of 45 patients were evaluated using a 12-marker immunohistochemistry panel. The primary end point was the prevalence of potentially actionable markers. Results: At least one expressed marker in each case could be identified. We noted a high prevalence of EGFR (80%, 39/45) and MET (57.4%, 28/45). Three patients received oncopanel-based therapy with variable results. Conclusion: Despite the limited number of treated subjects, oncopanel analysis in end-stage head and neck cancer is operationally and technically feasible. Combination with targeted next generation sequencing might provide additional therapy options.

Selection of systemic therapy in patients with locally advanced and recurrent/metastatic head and neck cancer: RAND-based expert opinion by an Italian multidisciplinary panel

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease often presenting at an already advanced stage. Cisplatin chemoradiotherapy is the standard treatment for locally advanced disease, although its efficacy varies according to different studies. Thus, treatment selection is a challenge, especially in older patients, who frequently have several comorbidities. Moreover, the majority of patients with recurrent and/or metastatic disease are unsuitable for local treatment, either surgery or radiation therapy. The only treatment option for them is systemic therapy, but prognosis remains poor, with a median overall survival of less than 12 months.

METHODS

A group of Italian key opinion leaders in the field of HNSCC gathered several times in 2018 in order to retrieve a set of statements to help clinicians in their daily decision-making process for the treatment of patients with different scenarios of HNSCC.

RESULTS AND CONCLUSION

The panel agreed on 22 statements that were identified as "good clinical points" based on the available literature or after discussion of the most relevant aspect of the underlying diseases when no international consensus was available. The panel identified a number of possible scenarios (namely 71) in which these statements may be helpful to guide decision-making for the best treatment selection.

Colonic stent-induced mechanical compression may suppress cancer cell proliferation in malignant large bowel obstruction

BACKGROUND

The short-term safety and efficacy of insertion of a self-expandable metallic colonic stent (SEMS) followed by elective surgery, "bridge to surgery (BTS)", for malignant large bowel obstruction (MLBO) have been well described; however, the influence on long-term oncological outcomes is unclear. The aim of this study was to evaluate changes in oncological characteristics in colorectal cancer (CRC) tissues after SEMS insertion, focusing on growth factors, cell cycle and apoptosis.

METHODS

From January 2013 to September 2014, a total of 25 patients with MLBO who underwent BTS at our single institution were retrospectively included. Paired CRC tissue samples before (endoscopic biopsy) and after SEMS insertion (surgically resected) were collected from each patient. EGFR, VEGF, Ki-67, p27kip1 and TUNEL expression were determined by immunohistochemistry.

RESULTS

No clinical or subclinical perforations evaluated by mechanical ulceration pathologically were observed. Epithelial exfoliation, tumour necrosis, infiltration of inflammatory cells and fibrosis were observed in SEMS-inserted surgically-resected specimens. Overall, 84% (21/25) and 60% (15/25) of patients exhibited no change or a decrease in staining category, respectively, for EGFR and VEGF expression after SEMS insertion. A significant decrease in Ki-67 expression was observed in surgically-resected specimens compared with endoscopic biopsy specimens (P < 0.01). The upstream cell cycle inhibitor, p27kip1, was significantly increased after SEMS insertion (P = 0.049).

CONCLUSIONS

Although the long-term safety of BTS should be determined in a future clinical trial, mechanical compression by SEMS may suppress cancer cell proliferation and this result could provide some insights into the issue.

Tumor Tissue Explant Culture of Patient-Derived Xenograft as Potential Prioritization Tool for Targeted Therapy

Despite of remarkable progress made in the head and neck cancer (HNC) therapy, the survival rate of this metastatic disease remain low. Tailoring the appropriate therapy to patients is a major challenge and highlights the unmet need to have a good preclinical model that will predict clinical response. Hence, we developed an accurate and time efficient drug screening method of tumor ex vivo analysis (TEVA) system, which can predict patient-specific drug responses. In this study, we generated six patient derived xenografts (PDXs) which were utilized for TEVA. Briefly, PDXs were cut into 2 × 2 × 2 mm3 explants and treated with clinically relevant drugs for 24 h. Tumor cell proliferation and death were evaluated by immunohistochemistry and TEVA score was calculated. Ex vivo and in vivo drug efficacy studies were performed on four PDXs and three drugs side-by-side to explore correlation between TEVA and PDX treatment in vivo. Efficacy of drug combinations was also ventured. Optimization of the culture timings dictated 24 h to be the time frame to detect drug responses and drug penetrates 2 × 2 × 2 mm3 explants as signaling pathways were significantly altered. Tumor responses to drugs in TEVA, significantly corresponds with the drug efficacy in mice. Overall, this low cost, robust, relatively simple and efficient 3D tissue-based method, employing material from one PDX, can bypass the necessity of drug validation in immune-incompetent PDX-bearing mice. Our data provides a potential rationale for utilizing TEVA to predict tumor response to targeted and chemo therapies when multiple targets are proposed.

EGFR Protein Expression of KRAS Wild-Type Colorectal Cancer: Predictive Value of the Sidedness for Efficacy of Anti-EGFR Therapy

Right- and left-sided colorectal cancers (RSCRC and LSCRC, respectively) are different developmentally, genetically and prognostically. Clinical data also indicate that they respond differently to anti-EGFR therapies. The role of EGFR protein expression in KRAS wild type colorectal cancer is also controversial. Here we have used a cohort of anti-EGFR antibody treated KRAS-wild type colorectal cancer patients (n = 97) to analyse the prognostic role of EGFR protein expression in relation to sidedness. In our cohort EGFR copy number, determined by FISH, was not associated with the level of EGFR protein, assessed by immunohistochemistry and measured by H-scoring. There was a significantly higher EGFR H-score detected in RSCRC as compared to LSCRC in primary tumors (p = 0.04). Furthermore, in a proportion of cases (n = 31) metastatic tissues were also available and their analysis also found a significantly higher EGFR H-score in metastases of RSCRC compared to LSCRC (p = 0.018). Kaplan Meyer survival analysis demonstrated that anti-EGFR antibody therapies were more effective in case of LSCRC compared to RSCRC. Although in case of progression-free survival data just indicated a trend (p = 0.065), in case of overall survival the difference was significant favouring LSCRC (p = 0.047). These data demonstrated for the first time that the EGFR protein expression is significantly higher in KRAS wild type RSLCL as compared to LSCRC. Meanwhile it is somewhat unexpected that the lower EGFR protein expression was found to be associated with better efficacy of anti-EGFR antibody therapies of colorectal cancer, the finding of which must be further validated.

The Roles of Common Variation and Somatic Mutation in Cancer Pharmacogenomics

Cancer pharmacogenomics is the science concerned with understanding genetic alterations and its effects on the pharmacokinetics and pharmacodynamics of anti-cancer drugs, with the aim to provide cancer patients with the precise medication that will achieve a good response and cause low/no incidence of adverse events. Advances in biotechnology and bioinformatics have enabled genomic research to evolve from the evaluation of alterations at the single-gene level to studies on the whole-genome scale using large-scale genotyping and next generation sequencing techniques. International collaborative efforts have resulted in the construction of databases to curate the identified genetic alterations that are clinically significant, and these are currently utilized in clinical sequencing and liquid biopsy screening/monitoring. Furthermore, countless clinical studies have accumulated sufficient evidence to match cancer patients to therapies by utilizing the information of clinical-relevant alterations. In this review we summarize the importance of germline alterations that act as predictive biomarkers for drug-induced toxicity and drug response as well as somatic mutations in cancer cells that function as drug targets. The integration of genomics into the medical field has transformed the era of cancer therapy from one-size-fits-all to cancer precision medicine.

An update: emerging drugs to treat squamous cell carcinomas of the head and neck

Introduction: Subsequent to the 2006 FDA approval of cetuximab, a variety of molecular targeting agents have been evaluated in head and neck squamous cell carcinoma (HNSCC). The treatment outcomes of recurrent and/or metastatic (R/M) HNSCC, in particular, remain dismal. The 2016 FDA approval of PD-1 immune checkpoint inhibitors has expanded the treatment options for R/M HNSCC and highlights the potential for immune-based therapies. Areas covered: We will review the clinical application of EGFR-targeted agents, alone and in combination with other drugs. Molecular targeting agents directed against the IL6/PI3K/STAT3 signaling pathway will be covered. In addition, evaluation of immune checkpoint inhibitors in HNSCC, along with ongoing combination trials incorporating these agents, will be discussed. The expanded indications of emerging drugs and the potential clinical benefit of new drugs and treatment combinations will be summarized. Expert opinion: In recent years, there has been a major shift toward immunotherapy-based approaches for the treatment of HNSCC, leading to significant improvements in outcomes for a subset of patients. Leveraging the increased understanding of the genetic alterations that characterize individual HNSCC tumors will facilitate precision medicine approaches using targeted agents, immunotherapies, as well as standard chemotherapy and radiation.

Efficacy of Carboplatin/Paclitaxel-Based Radiochemotherapy in Locally Advanced Squamous Cell Carcinoma of Head and Neck

BACKGROUND

Cisplatin-based chemotherapy (CTX) is commonly used concurrently with radiotherapy for head and neck cancer. The value of CTX regimens other than cisplatin for locally advanced squamous cell carcinoma of head and neck (LASCCHN) has not been well established. Here we compare the outcome of patients treated with different platinum-based chemotherapy regimens.

METHODS

Medical records from 104 patients with LASCCHN treated with radiochemotherapy (RCTX) between February 2013 and August 2016 were analyzed.

RESULTS

All patients were treated with intensity-modulated radiation therapy (51 definitive, 53 postoperative). The median total dose was 66.6 Gy and the median fraction dose was 1.8 Gy. 81 (78%) patients were administered cisplatin CTX, 23 (22%) patients received carboplatin and paclitaxel (CarboTaxol). The rate of recurrence was 38% in patients treated with cisplatin and 30% in CarboTaxol-treated patients (p = 0.6). Regarding the CTX regimens, event-free survival (EFS) was 37 versus 30 months (p = 0.6) and overall survival (OS) was 35 versus 28 months (p = 0.5) in cisplatin group versus CarboTaxol group, respectively. Significantly higher grade 3/4 acute toxicity in terms of dysphagia was observed following cisplatin-based RCTX (p = 0.002). In multivariable analysis, females and patients with early primary tumors (T1-2) have longer EFS and OS, regardless the CTX regimen.

CONCLUSIONS

Primary or adjuvant RCXT with CarboTaxol is a safe and effective treatment alternative for LASCCHN patients with contraindication to cisplatin-based RCTX.

Phase 1 study of EGFR-antisense DNA, cetuximab, and radiotherapy in head and neck cancer with preclinical correlatives

BACKGROUND

Cetuximab combined with radiation therapy (RT) is an evidence-based treatment for locally advanced head and neck squamous cell carcinoma (HNSCC); however, locoregional failure remains the primary cause of cancer-related death in this disease. Intratumoral injection of epidermal growth factor receptor (EGFR)-antisense plasmid DNA (EGFR-AS) is safe and has been associated with promising lesional responses in patients who have recurrent/metastatic HNSCC. For the current study, the authors investigated the antitumor effects of cetuximab and EGFR-AS in preclinical HNSCC models and reported their phase 1 experience adding intratumoral EGFR-AS to cetuximab RT.

METHODS

Antitumor mechanisms were investigated in cell line and xenograft models. Phase 1 trial eligibility required stage IVA through IVC HNSCC and a measurable lesion accessible for repeat injections. Patients received standard cetuximab was for 9 weeks. EGFR-AS was injected weekly until they achieved a lesional complete response. RT was delivered by conventional fractionation for 7 weeks, starting at week 3. Research biopsies were obtained at baseline and week 2.

RESULTS

When added to cetuximab, EGFR-AS decreased cell viability and xenograft growth compared with EGFR-sense control, partially mediated by reduced EGFR expression. Six patients were enrolled in the phase 1 cohort. No grade 2 or greater EGFR-AS-related adverse events occurred. The best lesional response was a complete response (4 patients), and 1 patient each had a partial response and disease progression. EGFR expression decreased in 4 patients who had available paired specimens.

CONCLUSIONS

In preclinical models, dual EGFR inhibition with cetuximab and EGFR-AS enhanced antitumor effects. In a phase 1 cohort, intratumoral EGFR-AS injections, cetuximab, and RT were well tolerated. A phase 2 trial is needed to conduct an extended evaluation of safety and to establish efficacy.

Optimizing treatments for recurrent or metastatic head and neck squamous cell carcinoma

INTRODUCTION

The majority of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) will recur. The treatment of patients with recurrent/metastatic (R/M HNSCC) is rapidly evolving. Areas covered: This article will comprehensively review the current systemic treatment of R/M HNSCC. Expert commentary: For the time being, the EXTREME regimen (cetuximab in combination with platinum and 5-fluorouracil) still remains standard of care in previously untreated R/M HNSCC patients who are candidates for combination chemotherapy. Single agents with well documented activity in HNSCC include methotrexate, cisplatin, 5-FU, docetaxel, and paclitaxel. The anti-PD-1 monoclonal antibody nivolumab can be considered the current standard of care in patients with R/M HNSCC progressing after platinum-based therapy based on the results of CheckMate 141 showing a survival benefit over standard of care drugs, such as single agent weekly cetuximab, methotrexate, or docetaxel. Multiple randomized phase III trials comparing anti-PD(L)-antibodies either as single agent or in combination with chemotherapy or an anti-CTLA-4 with the EXTREME as fist line treatment are ongoing or planned. The outcome of these trials might change the current treatment paradigm in previously untreated R/M HNSCC. Immunotherapeutic agents under active investigation include Toll-like receptor 8 agonists and inhibitors of IDO1.

Nuclear Klf4 accumulation is associated with cetuximab drug-resistance and predicts poor prognosis of nasopharyngeal carcinoma

Background

The functions of the protein expressed in the nucleus and cytoplasm were different or opposite. The previous study found that oncogene Klf4 played a role of tumor suppressor in the nasopharyngeal cytoplasm. Cetuximab targeted epidermal growth factor receptor (EGFR) for the treatment of nasopharyngeal carcinoma.

Methods

A cohort of 231 cases of advanced nasopharyngeal carcinoma (7th AJCC III–IVa) samples was assessed by immunohistochemistry (IHC), of which, 63 cases were treated with basic treatment without cetuximab, the basic treatment include chemotherapy and radiotherapy, the regent of the chemotherapy include cisplatin and fluorouracil and 168 cases were treated with cetuximab in addition to the basic treatment. The expression of the KLF4 protein was detected in nucleus and cytoplasm, c-Met protein and nuclear EGFR protein (nEGFR) by IHC, and H-Ras and PI3K mutations by an arms-PCR method in vivo. KLF4 was found to specifically express in the cytoplasm by deleting the NES, while H-Ras and PI3K genes were mutated in the nasopharyngeal carcinoma 5–8F and HONE1cell line. The cetuximab resistance in differentially mutated 5–8F and HONE1 cells was analyzed.

Results

The expression of Klf4 in the nucleus was associated with prognosis in 168 patients with cetuximab-treated nasopharyngeal carcinoma, which was found by retrospective analysis. The KLF4 expression in the nucleus was not significantly correlated with the prognosis in 63 nasopharyngeal carcinoma patients treated with basic treatment (P = 0.261). The expression of Klf4 in the nucleus was correlated with mutations of H-Ras and PI3K in 168 cases of nasopharyngeal carcinoma with cetuximab treatment. In vitro experiments showed that Klf4 was specifically expressed in the nucleus of 5–8F and HONE1 cells as assessed by deleting nuclear export signal, which led to cetuximab resistance. H-Ras and PI3K mutations in 5–8F and HONE1 cells also led to the expression of Klf4 in the nucleus and resistance to cetuximab. In HONE1 cells, Klf4 was specifically localized in the cytoplasm by deleting the NES, and the H-Ras and PI3K mutations did not result in an increased expression of Klf4 in the nucleus and cetuximab resistance.

Conclusion

The prognosis of nasopharyngeal carcinoma was not significantly improved by cetuximab treatment when the Klf4 was highly expressed in the nucleus of nasopharyngeal carcinoma tissues. The expression of Klf4 in the nucleus can be used as a biomarker for predicting the effects of cetuximab treatment in nasopharyngeal carcinoma, which might be attributed to the H-RAS and PI3K mutations, leading to cetuximab resistance.

[Genomic characterization of head and neck squamous cell carcinoma: Impact and challenges for therapeutic management]

Squamous cell carcinomas are the most frequent subgroup among head and neck malignant tumors (HNSCC). Tobacco (±alcohol) and HPV infection, the two main risk factors, define two entities with distinct anatomo-clinical and genetic features. HPV-positive, non-tobacco-related HNSCCs are associated with a better prognosis, a rather simple genomic profile, frequent activating mutations of genes involved in pi3kinase-pathway, and the scarcity of mutations of tumor suppressor genes. HPV-negative, tobacco-related HNSCC are genetically more complex, are characterized by almost mandatory inactivating mutations/deletions of tumor suppressor genes (TP53, CDKN2A) and the possible, but less frequent, activating mutations or amplifications of some oncogenes that encode for cell cycle proteins or receptors with tyrosine kinase activity. This review describes the genetic features of HNSCC and discusses how these abnormalities could be incorporated into a therapeutic approach.

Precision Medicine in Head and Neck Cancer: Myth or Reality?

Standard treatment in head and neck squamous cell carcinoma (HNSCC) is limited currently with decisions being made primarily based on tumor location, histology, and stage. The role of the human papillomavirus in risk stratification is actively under clinical trial evaluations. The molecular complexity and intratumoral heterogeneity of the disease are not actively integrated into management decisions of HNSCC, despite a growing body of knowledge in these areas. The advent of the genomic era has delivered vast amounts of information regarding different cancer subtypes and is providing new therapeutic targets, which can potentially be elucidated using next-generation sequencing and other modern technologies. The task ahead is to expand beyond the existent armamentarium by exploiting beyond the genome and perform integrative analysis using innovative systems biology methods, with the goal to deliver effective precision medicine-based theragnostic options in HNSCC.

Targeting phosphoinositide 3-kinase (PI3K) in head and neck squamous cell carcinoma (HNSCC)

The landscape of head and neck squamous cell carcinoma (HNSCC) has been changing rapidly due to growing proportion of HPV-related disease and development of new therapeutic agents. At the same time, there has been a constant need for individually tailored treatment based on genetic biomarkers in order to optimize patient survival and alleviate treatment-related toxicities. In this regard, aberrations of PI3K pathway have important clinical implications in the treatment of HNSCC. They frequently constitute ‘gain of function’ mutations which trigger oncogenesis, and PI3K mutations can also lead to emergence of drug resistance after treatment with EGFR inhibitors. In this article, we review PI3K pathway as a target of treatment for HNSCC and summarize PI3K/mTOR inhibitors that are currently under clinical trials. In light of recent advancement of immune checkpoint inhibitors, consideration of PI3K inhibitors as potential immune modulators is also suggested.