Management of recurrent head and neck cancer: recent progress and future directions

Detection and impact of hypoxic regions in multicellular tumor spheroid cultures formed by head and neck squamous cell carcinoma cells lines

In solid tumors like head and neck cancer (HNC), chronic and acute hypoxia have serious adverse clinical consequences including poorer overall patient prognosis, enhanced metastasis, increased genomic instability, and resistance to radiation-, chemo-, or immuno-therapies. However, cells in the two-dimensional monolayer cultures typically used for cancer drug discovery experience 20%-21% O₂ levels (normoxic) which are 4-fold higher than O₂ levels in normal tissues and ≥10-fold higher than in the hypoxic regions of solid tumors. The oxygen electrodes, exogenous bio-reductive markers, and increased expression of endogenous hypoxia-regulated proteins like HIF-1α generally used to mark hypoxic regions in solid tumors are impractical in large sample numbers and longitudinal studies. We used a novel homogeneous live-cell permeant HypoxiTRAK™ (HPTK) molecular probe compatible with high content imaging detection, analysis, and throughput to identify and quantify hypoxia levels in live HNC multicellular tumor spheroid (MCTS) cultures over time. Accumulation of fluorescence HPTK metabolite in live normoxic HNC MCTS cultures correlated with hypoxia detection by both pimonidazole and HIF-1α staining. In HNC MCTSs, hypoxic cytotoxicity ratios for the hypoxia activated prodrugs (HAP) evofosfamide and tirapazamine were much smaller than have been reported for uniformly hypoxic 2D monolayers in gas chambers, and many viable cells remained after HAP exposure. Cells in solid tumors and MCTSs experience three distinct O₂ microenvironments dictated by their distances from blood vessels or MCTS surfaces, respectively; oxic, hypoxic, or intermediate levels of hypoxia. These studies support the application of more physiologically relevant in vitro 3D models that recapitulate the heterogeneous microenvironments of solid tumors for preclinical cancer drug discovery.

Induction of synergistic non-apoptotic cell death by simultaneously targeting proteasomes with bortezomib and histone deacetylase 6 with ricolinostat in head and neck tumor cells

Following surgery and chemoradiation, ~50% of patients with locally advanced head and neck tumors experience relapse within the first two years, with a poor prognosis. Therefore, a novel therapeutic approach is required. The aim of the present study was to investigate the effect of combination treatment with the proteasome inhibitor bortezomib (BTZ), and ricolinostat (RCS), a specific inhibitor of histone deacetylase 6 (HDAC6), on CAL27 and Detroit562 head and neck cancer cells. BTZ and RCS exhibited cytotoxicity in a dose- and time-dependent manner. Simultaneous treatment with BTZ and RCS resulted in the synergistic enhancement of non-apoptotic cell death and autophagy. The receptor-interacting serine/threonine-protein kinase 1 (RIPK1) inhibitor, necrostatin, but not the autophagy inhibitor, 3-methyladenine, attenuated the cytotoxicity of combined BTZ and RCS treatment. Thus, necroptosis [type-III programmed cell death (PCD)], but not autophagic cell death (type-II PCD), appeared to contribute to the pronounced cytotoxicity. However, no phosphorylation of RIPK1 or mixed lineage kinase domain-like protein was detectable in response to BTZ or RCS. Furthermore, RCS induced α-tubulin acetylation and inhibited BTZ-induced aggresome formation along with endoplasmic reticulum stress loading. Combined treatment with BTZ and RCS enhanced the production of reactive oxygen species (ROS). The ROS scavenger, N-acetyl cysteine, abrogated the increase in cytotoxicity. These results suggest the potential therapeutic value of the dual targeting of the proteasome and HDCA6 for head and neck cancers through the induction of necroptosis-like cell death along with ROS generation.

SAHA Overcomes 5-FU Resistance in IFIT2-Depleted Oral Squamous Cell Carcinoma Cells

Simple Summary

IFIT2 depletion is associated with increased epithelial-mesenchymal transition and metastasis. The main aim of our study was to understand the link between drug resistance and IFIT2 depletion. In this study, we confirmed resistance to multiple common therapeutic drugs, particularly 5-FU, which showed especially high resistance in IFIT2-depleted cells. Interestingly, combination of SAHA and 5-FU overcame 5-FU resistance in IFIT2-depleted cells. Hence, our findings suggest that IFIT2 expression may be used as a biomarker to decide whether to undergo 5-FU treatment, but also the SAHA and 5-FU combination may be a potential new treatment regimen to augment 5-FU therapy in patients with thymidylate synthase-mediated drug-resistant oral squamous cell carcinoma.

Abstract

Interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) is a member of the interferon-stimulated gene family that contains tetratricopeptide repeats (TPRs), which mediate protein–protein interactions in various biological systems. We previously showed the depletion of IFIT2 enhanced cell migration and metastatic activity in oral squamous cell carcinoma (OSCC) cells via the activation of atypical PKC signaling. In this study, we found that IFIT2-knockdown cells displayed higher resistance to 5-fluorouracil (5-FU) than control cells. The comet assay and annexin V analysis showed decreased DNA damage and cell death in IFIT2-knockdown cells compared to control cells treated with 5-FU. Cell cycle progression was also perturbed by 5-FU treatment, with the accumulation of IFIT2-depleted cells in S phase in a time-dependent manner. We further observed the overexpression of thymidylate synthase (TS) and thymidine kinase (TK) in IFIT2-knockdown cells. Inhibition of TS alone or double inhibition of TS and TK1 using the siRNA technique increased susceptibility to 5-FU in IFIT2-knockdown cells. We further identified that suberanilohydroxamic acid (SAHA) treatment decreased the expression of TS in IFIT2-knockdown cells and demonstrated that pretreatment with SAHA sensitized IFIT2-knockdown cells to 5-FU in vitro and in vivo. In conclusion, IFIT2 knockdown enhances TS expression, which mediates 5-FU resistance, and SAHA pretreatment suppresses TS expression and hence sensitizes cells to 5-FU. SAHA will be an effective strategy for the treatment of OSCC patients with 5-FU resistance.

Adaptive ERK signalling activation in response to therapy and in silico prognostic evaluation of EGFR-MAPK in HNSCC

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) patients frequently develop treatment resistance to cetuximab, a monoclonal antibody against EGFR, as well as radiotherapy. Here we addressed extracellular signal-regulated kinase 1/2 (ERK1/2) regulation by cetuximab or fractionated irradiation (IR) and conducted in silico prognostic evaluation of the EGFR-MAPK axis in HNSCC.

METHODS

Expression of ERK1/2 phosphorylation (pERK1/2) was determined in HNSCC cell lines, which were treated with cetuximab or fractionated-IR. Furthermore, the effect of fractionated IR on pERK1/2 was confirmed in an ex vivo HNSCC tissue culture model. Expression and prognostic significance of EGFR-ERK axis was evaluated in a cohort of radiotherapy plus cetuximab-treated HNSCC. Correlations among EGFR-MAPK signalling components and association between transcript and protein expression profiles and patient survival in HNSCC were analysed using publicly available databases.

RESULTS

ERK1/2 phosphorylation was rebounded by prolonged cetuximab administration and was induced by fractionated IR, which could be suppressed by a MEK inhibitor as a radiosensitiser. In silico assessments suggested that EGFR-MAPK cascade genes and proteins could predict HNSCC patients' survival as a prognostic signature.

CONCLUSIONS

Activation of ERK1/2 signalling contributes to the cellular defence of HNSCC against cetuximab and fractionated IR treatment. EGFR-MAPK axis has a prognostic significance in HNSCC.

Maximizing the Value of Cancer Drug Screening in Multicellular Tumor Spheroid Cultures: A Case Study in Five Head and Neck Squamous Cell Carcinoma Cell Lines

With approval rates <5% and the probability of success in oncology clinical trials of 3.4%, more physiologically relevant in vitro three-dimensional models are being deployed during lead generation to select better drug candidates for solid tumors. Multicellular tumor spheroids (MCTSs) resemble avascular tumor nodules, micrometastases, or the intervascular regions of large solid tumors with respect to morphology, cell-cell and cell-extracellular matrix contacts, and volume growth kinetics. MCTSs develop gradients of nutrient and oxygen concentration resulting in diverse microenvironments with differential proliferation and drug distribution zones. We produced head and neck squamous cell carcinoma (HNSCC) MCTSs in 384-well U-bottom ultra-low-attachment microtiter plates and used metabolic viability and imaging methods to measure morphologies, growth phenotypes and the effects of 19 anticancer drugs. We showed that cell viability measurements underestimated the impact of drug exposure in HNSCC MCTS cultures, but that incorporating morphology and dead-cell staining analyses increased the number of drugs judged to have substantially impacted MCTS cultures. A cumulative multiparameter drug impact score enabled us to stratify MCTS drug responses into high-, intermediate-, and low-impact tiers, and maximized the value of these more physiologically relevant tumor cultures. It is conceivable that the viable cells present in MCTS cultures after drug exposure arise from drug-resistant populations that could represent a source of drug failure and recurrence. Long-term monitoring of treated MCTS cultures could provide a strategy to determine whether these drug-resistant populations represent circumstances where tumor growth is delayed and may ultimately give rise to regrowth.

Methotrexate plus or minus cetuximab as first-line treatment in a recurrent or metastatic (R/M) squamous cell carcinoma population of the head and neck (SCCHN), unfit for cisplatin combination treatment, a phase Ib-randomized phase II study Commence

BACKGROUND

Methotrexate in recurrent or metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN) has limited progression-free survival (PFS) benefit. We hypothesized that adding cetuximab to methotrexate improves PFS.

METHODS

In the phase-Ib-study, patients with R/M SCCHN received methotrexate and cetuximab as first-line treatment. The primary objective was feasibility. In the phase-II-study patients were randomized to this combination or methotrexate alone (2:1). The primary endpoint was PFS. Secondary endpoints were overall survival (OS), toxicity, and quality of life (QoL).

RESULTS

In six patients in the phase-Ib-study, no dose limiting toxicities were observed. In the phase II study, 30 patients received the combination and 15 patients methotrexate. In the phase-II-study median PFS was 4.5 months in the combination group vs 2.0 months in the methotrexate group (HR 0.37; P = .002). OS, toxicity, and QoL were not significantly different.

CONCLUSION

Cetuximab with methotrexate improved PFS without increased toxicity in R/M SCCHN-patients.

High Content Screening Characterization of Head and Neck Squamous Cell Carcinoma Multicellular Tumor Spheroid Cultures Generated in 384-Well Ultra-Low Attachment Plates to Screen for Better Cancer Drug Leads

Multicellular tumor spheroid (MCTS) cultures represent more physiologically relevant in vitro cell tumor models that recapitulate the microenvironments and cell-cell or cell-extracellular matrix interactions which occur in solid tumors. We characterized the morphologies, viability, and growth behaviors of MCTSs produced by 11 different head and neck squamous cell carcinoma (HNSCC) cell lines seeded into and cultured in ultra-low attachment microtiter plates (ULA-plates) over extended periods of time. HNSCC MCTS cultures developed microenvironments, which resulted in differences in proliferation rates, metabolic activity, and mitochondrial functional activity between cells located in the outer layers of the MCTS and cells in the interior. HNSCC MCTS cultures exhibited drug penetration and distribution gradients and some developed necrotic cores. Perhaps the most profound effect of culturing HNSCC cell lines in MCTS cultures was their dramatically altered and varied growth phenotypes. Instead of the exponential growth that are characteristic of two-dimensional HNSCC growth inhibition assays, some MCTS cultures displayed linear growth rates, categorized as rapid, moderate, or slow, dormant MCTSs remained viable but did not grow, and some MCTSs exhibited death phenotypes that were either progressive and slow or rapid. The ability of MCTS cultures to develop microenvironments and to display a variety of different growth phenotypes provides in vitro models that are more closely aligned with solid tumors in vivo. We anticipate that the implementation MCTS models to screen for new cancer drugs for solid tumors like HNSCC will produce leads that will translate better in in vivo animal models and patients.

Antibody-assisted target identification reveals afatinib, an EGFR covalent inhibitor, down-regulating ribonucleotide reductase

Afatinib, used for the first-line treatment of non-small-cell lung carcinoma (NSCLC) patients with distinct epidermal growth factor receptor (EGFR) mutations, inactivates EGFR by mimicking ATP structure and forming a covalent adduct with EGFR. We developed a method to unravel potential targets of afatinib in NSCLC cells through immunoprecipitation of afatinib-labeling proteins with anti-afatinib antiserum and mass spectrometry analysis. Ribonucleotide reductase (RNR) is one of target proteins of afatinib revealed by this method. Treatment of afatinib at 10-100 nM potently inhibited intracellular RNR activity in an in vitro assay using permeabilized PC-9 cells (formerly known as PC-14). PC-9 cells treated with 10 μM afatinib displayed elevated markers of DNA damage. Long-term treatment of therapeutic concentrations of afatinib in PC-9 cells caused significant decrease in protein levels of RNR subunit M2 at 1-10 nM and RNR subunit M1 at 100 nM. EGFR-null Chinese hamster ovary (CHO) cells treated with afatinib also showed similar effects. Afatinib repressed the upregulation of RNR subunit M2 induced by gemcitabine. Covalent modification with afatinib resulting in inhibition and protein downregulation of RNR underscores the therapeutic and off-target effects of afatinib. Afatinib may serve as a lead compound of chemotherapeutic drugs targeting RNR. This method can be widely used in the identification of potential targets of other covalent drugs.

High Content Imaging Assays for IL-6-Induced STAT3 Pathway Activation in Head and Neck Cancer Cell Lines

In the canonical STAT3 signaling pathway, IL-6 receptor engagement leads to the recruitment of latent STAT3 to the activated IL-6 complex and the associated Janus kinase (JAK) phosphorylates STAT3 at Y705. pSTAT3-Y705 dimers traffic into the nucleus and bind to specific DNA response elements in the promoters of target genes to regulate their transcription. However, IL-6 receptor activation induces the phosphorylation of both the Y705 and S727 residues of STAT3, and S727 phosphorylation is required to achieve maximal STAT3 transcriptional activity. STAT3 continuously shuttles between the nucleus and cytoplasm and maintains a prominent nuclear presence that is independent of Y705 phosphorylation. The constitutive nuclear entry of un-phosphorylated STAT3 (U-STAT3) drives expression of a second round of genes by a mechanism distinct from that used by pSTAT3-Y705 dimers. The abnormally elevated levels of U-STAT3 produced by the constitutive activation of pSTAT3-Y705 observed in many tumors drive the expression of an additional set of pSTAT3-independent genes that contribute to tumorigenesis. In this chapter, we describe the HCS assay methods to measure IL-6-induced STAT3 signaling pathway activation in head and neck tumor cell lines as revealed by the expression and subcellular distribution of pSTAT3-Y705, pSTAT3-S727, and U-STAT3. Only the larger dynamic range provided by the pSTAT3-Y705 antibody would be robust and reproducible enough for screening.

High expression of myoferlin is associated with poor outcome in oropharyngeal squamous cell carcinoma patients and is inversely associated with HPV-status

Myoferlin (MYOF) is a member of ferlin family of membrane proteins that was originally discovered as a muscle specific protein. Recent studies have shown that myoferlin is also expressed in other cell types including endothelial cells and cancer cells. However, very little is known about the expression and biological role of myoferlin in head and neck cancer. In this study, we examined expression profile of myoferlin in oropharyngeal squamous cell carcinoma (OPSCC) and assessed its correlation with disease progression and patient outcome. In univariate analyses, nuclear MYOF was associated with poor overall survival (p<0.001) and these patients had 5.5 times increased hazard of death (95% Cl 3.4-8.8). Nuclear myoferlin expression was also directly associated with tumor recurrence (p<0.001), perineural invasion (p=0.008), extracapsular spread (p=0.009), higher T-stage (p=0.0015) and distant metastasis (p<0.001). In addition, nuclear MYOF expression was directly associated with IL-6 (p<0.001) and inversely with HPV status (p=0.0014). In a subgroup survival analysis, MYOF nuclear+/IL-6+ group had worst survival (84.6% mortality), whereas MYOF nuclear-/IL-6- had the best survival. Similarly, patients with HPV-negative/MYOF-positive tumors had worse survival compared to HPV-positive/MYOF-negative. Taken together, our results demonstrate for the first time that nuclear myoferlin expression independently predicts poor clinical outcome in OPSCC patients.

Benefits of Multifaceted Chemopreventives in the Suppression of the Oral Squamous Cell Carcinoma (OSCC) Tumorigenic Phenotype

Over one third of patients who have undergone oral squamous cell carcinoma (OSCC) surgical resections develop life-threatening and often untreatable recurrences. A variety of drugs, intended for management of recurrent or disseminated cancers, were designed to exploit cancer cells' reliance upon overexpressed receptors and gratuitous signaling. Despite their conceptual promise, clinical trials showed these agents lacked efficacy and were often toxic. These findings are consistent with evasion of pathway-targeted treatments via extensive signaling redundancies and compensatory mechanisms common to cancers. Optimal secondary OSCC chemoprevention requires long-term efficacy with multifaceted, nontoxic agents. Accordingly, this study evaluated the abilities of three complementary chemopreventives, that is, the vitamin A derivative fenretinide (4-HPR, induces apoptosis and differentiation, inhibits signaling proteins, and invasion), the estrogen metabolite 2-methoxyestradiol (2-ME, apoptosis-inducing, antiangiogenic), and the humanized mAb to the IL6R receptor tocilizumab (TOC, reduces IL6 signaling) to suppress OSCC gratuitous signaling and tumorigenesis. Modeling studies demonstrated 4-HPR's high-affinity binding at STAT3's dimerization site and c-Abl and c-Src ATP-binding kinase sites. Although individual agents suppressed cancer-promoting pathways including STAT3 phosphorylation, STAT3-DNA binding, and production of the trans-signaling enabling sIL6R, maximal chemopreventive effects were observed with agent combinations. OSCC tumor xenograft studies showed that locally delivered TOC, TOC+4-HPR, and TOC+4-HPR+2-ME treatments all prevented significant tumor growth. Notably, the TOC+4-HPR+2-ME treatment resulted in the smallest overall increase in tumor volume. The selected agents use diverse mechanisms to disrupt tumorigenesis at multiple venues, that is, intracellular, tumor cell-ECM, and tumor microenvironment; beneficial qualities for secondary chemopreventives. Cancer Prev Res; 10(1); 76-88. ©2016 AACR.

HCS campaign to identify selective inhibitors of IL-6-induced STAT3 pathway activation in head and neck cancer cell lines

Signal transducer and activator of transcription factor 3 (STAT3) is hyperactivated in head and neck squamous cell carcinomas (HNSCC). Cumulative evidence indicates that IL-6 production by HNSCC cells and/or stromal cells in the tumor microenvironment activates STAT3 and contributes to tumor progression and drug resistance. A library of 94,491 compounds from the Molecular Library Screening Center Network (MLSCN) was screened for the ability to inhibit interleukin-6 (IL-6)-induced pSTAT3 activation. For contractual reasons, the primary high-content screening (HCS) campaign was conducted over several months in 3 distinct phases; 1,068 (1.1%) primary HCS actives remained after cytotoxic or fluorescent outliers were eliminated. One thousand one hundred eighty-seven compounds were cherry-picked for confirmation; actives identified in the primary HCS and compounds selected by a structural similarity search of the remaining MLSCN library using hits identified in phases I and II of the screen. Actives were confirmed in pSTAT3 IC50 assays, and an IFNγ-induced pSTAT1 activation assay was used to prioritize selective inhibitors of STAT3 activation that would not inhibit STAT1 tumor suppressor functions. Two hundred three concentration-dependent inhibitors of IL-6-induced pSTAT3 activation were identified and 89 of these also produced IC50s against IFN-γ-induced pSTAT1 activation. Forty-nine compounds met our hit criteria: they reproducibly inhibited IL-6-induced pSTAT3 activation by ≥70% at 20 μM; their pSTAT3 activation IC50s were ≤25 μM; they were ≥2-fold selective for pSTAT3 inhibition over pSTAT1 inhibition; a cross target query of PubChem indicated that they were not biologically promiscuous; and they were ≥90% pure. Twenty-six chemically tractable hits that passed filters for nuisance compounds and had acceptable drug-like and ADME-Tox properties by computational evaluation were purchased for characterization. The hit structures were distributed among 5 clusters and 8 singletons. Twenty-four compounds inhibited IL-6-induced pSTAT3 activation with IC50s ≤20 μM and 13 were ≥3-fold selective versus inhibition of pSTAT1 activation. Eighteen hits inhibited the growth of HNSCC cell lines with average IC50s ≤ 20 μM. Four chemical series were progressed into lead optimization: the guanidinoquinazolines, the triazolothiadiazines, the amino alcohols, and an oxazole-piperazine singleton.

CD24 Expression May Play a Role as a Predictive Indicator and a Modulator of Cisplatin Treatment Response in Head and Neck Squamous Cellular Carcinoma

Platinum-based therapy is most often used to treat advanced cases of head and neck cancers, but only a small fraction of the patient population responds to cisplatin, with a median survival time of less than a year. Although gene signatures and molecular etiology of head and neck cancers have been previously described, none of them are predictive indicators of cisplatin treatment response in particular. Therefore, currently, there is a lack of clinically employable predictive indicators of the disease beyond HPV status to specifically predict patients' response to platinum-based therapy. It beckons a substantial effort to look for predictive indicators of cisplatin treatment response. In this regard, CD24 expression level appears to be a significant molecular phenotype of cisplatin-resistant residual cells in laryngeal carcinoma lines. CD24 expression level directly affects cisplatin sensitivity and affects the expression of critical apoptotic, stem and drug resistance genes. A relatively small retrospective patient tumor analysis suggests that CD24 high tumors go on to show an unfavorable response to cisplatin treatment. Overall, based on the strength of further analysis, CD24 presents a strong rationale to be utilized as a predictive indicator to stratify head and neck cancer patients for platinum-based therapy. It also provides a rationale for using CD24 as a therapeutic adjuvant target along with standard cisplatin therapy.

Temporal trends in outcome of oral squamous cell cancer in a resource-limited setting

AIMS AND BACKGROUND

Improving survival has been documented for oral squamous cell carcinoma in recent years. It is a common malignancy in Pakistan but survival outcomes have not been reported. The objective of this study was to determine survival and identify independent predictors in patients with oral squamous cell cancer in 2 different time periods.

METHODS

A retrospective review of patients who received treatment between 2003 and 2012 was performed. Patients were divided into two 5 year groups: group 1 (2003-2007) (n = 628) and group 2 (2008-2012) (n = 920). Demographics, risk factors, treatment approaches, and outcomes were compared. Disease-free and overall survival were calculated. Cox proportional hazard model was used to determine independent predictors of survival.

RESULTS

A significant difference was present for ethnicity and grade and clinical T and N stage of tumors, with earlier presentation in group 2. More patients underwent surgery (p = 0.001) and had radical treatment intent (p&lt;0.0001) in recent years. Induction chemotherapy (p&lt;0.0001) and palliative chemotherapy (p&lt;0.0001) were used more frequently. No significant difference in disease-free survival was observed but overall 5-year survival improved significantly (23% vs 42%) (p&lt;0.0001). Use of palliative chemotherapy reduced risk of death significantly (hazard ratio [HR] 0.1, confidence interval [CI] 0.02-0.4, p = 0.003), while pathologic nodal positivity significantly increased the risk (HR 2.5, CI 1-5.9, p = 0.03).

CONCLUSIONS

These results from a single cancer hospital demonstrate improvement in overall survival secondary to early detection, better patient selection, and use of palliative chemotherapy in the later period.

An audit of the results of a triplet metronomic chemotherapy regimen incorporating a tyrosine kinase inhibitor in recurrent/metastatic head and neck cancers patients

BACKGROUND

Addition of erlotinib to metronomic chemotherapy (MCT) may lead to further improvement in progression-free survival (PFS) and overall survival in head and neck cancers. The aim of this study was to study the PFS with MCT + erlotinib combination in our setting.

METHODS

A single-arm prospective observational study conducted at Malabar Cancer Center. Patients warranting palliative chemotherapy for head and neck cancers, having adequate organ function, not-affording cetuximab and not willing for intravenous chemotherapy were included in this study. Oral methotrexate (15 mg/m(2)/week), oral celecoxib (200 mg twice daily), and erlotinib (150 mg once daily) were administered till the progression of the disease or till intolerable side-effects. Patients underwent toxicity (CTCAE version 4.02) and response (RECIST version 1.1) assessment every 30 days. Statistical analysis was performed using SPSS version 16 (IBM, New York, USA). Descriptive statistics and Kaplan-Meier analysis have been performed.

RESULTS

A total of 15 patients received MCT. The median age of these patients was 65 years (range: 48-80). The Eastern Cooperative Oncology Group Performance Status was 0-1 in seven patients (46.7%), while it was 2 in eight patients (53.3%). The primary sites of tumor were predominantly oral cavity, 11 (73.4%). Prior to MCT, treatment with palliative radiation therapy was given in 11 patients and curative treatment in two patients. The best response post-MCT was complete remission in two patients, partial remission in seven patients, stable disease in four patients, and progressive disease in two patients. The median estimated PFS was 148 days (95% confidence interval 95.47-200.52 days). For a median follow-up of 181 days, there were only three deaths. Grade 3-4 toxicity was seen in six patients (40%). Dose reduction was required in four patients (26.7%).

CONCLUSION

The addition of erlotinib to an MCT schedule of methotrexate and celecoxib resulted in a promising PFS and should be tested in future studies.

Second-line treatment of recurrent HNSCC: tumor debulking in combination with high-dose-rate brachytherapy and a simultaneous cetuximab-paclitaxel protocol

BACKGROUND AND PURPOSE

After the failure of first-line treatment, the clinical prognosis in head and neck cancer (HNSCC) deteriorates. Effective therapeutic strategies are limited due to the toxicity of previous treatments and the diminished tolerance of surrounding normal tissue. This study demonstrates a promising second-line regimen, with function preserving surgical tumor debulking, followed by a combination of postoperative interstitial brachytherapy and a simultaneous protocol of cetuximab and taxol.

PATIENTS AND METHODS

From January 2006 to May 2013, 197 patients with HNSCC were treated with brachytherapy at the University Hospital Schleswig-Holstein Campus Lübeck, including 94 patients due to recurrent cancer. Within these, 18 patients were referred to our clinic because of early progressive disease following first- or second-line treatment failure. They received the new palliative regimen. A matched-pair analysis including recurrent tumor stage, status of resection margins, tissue invasion and previous therapy was performed to evaluate this treatment retrospectively. Overall survival (OS), disease-free survival (DFS), functional outcome and treatment toxicity was analyzed on the basis of medical records and follow-up data.

RESULTS

DFS and OS of the study group were 8.7 and 14.8 months. Whereas, DFS and OS of the control group, treated only by function preserving tumor debulking and brachytherapy, was 3.9 and 6.1 months respectively. This demonstrates a positive trend through the additional use of the cetuximab-taxane protocol. Furthermore, no increase of therapy induced toxicities was displayed.

CONCLUSION

Pre-treated patients with a further relapse benefit from the 'cetuximab-taxane recurrency scheme'. It seems to be a valuable complement to interdisciplinary and multimodal tumor therapy, which improves OS and results in acceptable toxicity.

Gefitinib, Methotrexate and Methotrexate plus 5-Fluorouracil as palliative treatment in recurrent head and neck squamous cell carcinoma

This study compared the efficacy and toxicity of Gefitinib, Methotrexate and Methotrexate plus 5-Fluorouracil (5-FU) in patients of recurrent squamous cell carcinoma of head and neck (SCCHN) treated with palliative intent. Patients with recurrent SCCHN not amenable to curative treatment were randomly assigned to Gefitinib, Methotrexate or Methotrexate plus 5-FU arm. The primary end point was overall survival. Secondary end points of interest were objective response rate, toxicity and quality of life. Total 117 patients were analyzed. Median overall survival and objective response rates were 8.8 months, 7.8 months and 8.1 months and 7.7%, 5.0% and 7.9% in Gefitinib, Methotrexate and Methotrexate plus 5-FU arms respectively with no statistically significant difference between 3 arms. Gefitinib had different toxicity profile compared with other arms. Majority of toxicities were Grade 1 or Grade 2. Gefitinib had significant improvement in quality of life during initial months over Methotrexate. There was no suggestion that Gefitinib significantly prolonged overall survival compared with Methotrexate and Methotrexate plus 5-FU. However, improved Quality of Life with manageable toxicities was observed.

Production of Uniform 3D Microtumors in Hydrogel Microwell Arrays for Measurement of Viability, Morphology, and Signaling Pathway Activation

Despite significant investments in cancer research and drug discovery/development, the rate of new cancer drug approval is ≤5% and most cases of metastatic cancer remain incurable. Ninety-five percent of new cancer drugs fail in clinical development because of a lack of therapeutic efficacy and/or unacceptable toxicity. One of the major factors responsible for the low success rate of anticancer drug development is the failure of preclinical models to adequately recapitulate the complexity and heterogeneity of human cancer. For throughput and capacity reasons, high-throughput screening growth inhibition assays almost exclusively use two-dimensional (2D) monolayers of tumor cell lines cultured on tissue culture-treated plastic/glass surfaces in serum-containing medium. However, these 2D tumor cell line cultures fail to recapitulate the three-dimensional (3D) context of cells in solid tumors even though the tumor microenvironment has been shown to have a profound effect on anticancer drug responses. Tumor spheroids remain the best characterized and most widely used 3D models; however, spheroid sizes tend to be nonuniform, making them unsuitable for high-throughput drug testing. To circumvent this challenge, we have developed defined size microwell arrays using nonadhesive hydrogels that are applicable to a wide variety of cancer cell lines to fabricate size-controlled 3D microtumors. We demonstrate that the hydrogel microwell array platform can be applied successfully to generate hundreds of uniform microtumors within 3-6 days from many cervical and breast, as well as head and neck squamous cell carcinoma (HNSCC) cells. Moreover, controlling size of the microwells in the hydrogel array allows precise control over the size of the microtumors. Finally, we demonstrate the application of this platform technology to probe activation as well as inhibition of epidermal growth factor receptor (EGFR) signaling in 3D HNSCC microtumors in response to EGF and cetuximab treatments, respectively. We believe that the ability to generate large numbers of HNSCC microtumors of uniform size and 3D morphology using hydrogel arrays will provide more physiological in vitro 3D tumor models to investigate how tumor size influences signaling pathway activation and cancer drug efficacy.

Long-term remission of locally recurrent oropharyngeal cancer after docetaxel-based chemotherapy plus cetuximab

BACKGROUND

In recurrent head and neck squamous cell carcinoma ineligible for resection or irradiation, treatment aims primarily at symptom control and quality of life enhancement with an expected outcome of 6-12 months.

METHODS

In 2005, a male patient, born in 1944, with a second local recurrence of human papillomavirus negative tonsil cancer was enrolled in the EXTREME trial, and randomized to platinum/5-fluorouracil/cetuximab arm resulting in partial remission with progression-free survival of 12 months. The second-line systemic therapy comprised 5 cycles of 3-weekly docetaxel/cisplatin/5-fluorouracil regimen plus weekly cetuximab.

RESULTS

As confirmed on imaging and repeated biopsies, complete response was achieved with disease-free survival of 8 years and follow-up period of 12 years. Severe acute toxicities during the taxane-based chemotherapy plus cetuximab included grade 4 anorexia and grade 3 febrile neutropenia.

CONCLUSIONS

Poor tumor differentiation, no weight loss, oropharyngeal location, white race, and particularly the induced complete response were most likely the key favorable prognostic factors in the reported patient. The possibility of a synergistic interaction between taxanes and cetuximab should be further explored.

A prospective randomized phase II study comparing metronomic chemotherapy with chemotherapy (single agent cisplatin), in patients with metastatic, relapsed or inoperable squamous cell carcinoma of head and neck

BACKGROUND

Cetuximab based treatment is the recommended chemotherapy for head and neck squamous cell cancers in the palliative setting. However, due to financial constraints, intravenous (IV) chemotherapy without cetuximab is commonly used in lesser developed countries. We believe that oral metronomic chemotherapy may be safer and more effective in this setting.

METHODS

We conducted an open label, superiority, parallel design, randomized phase II trial comparing oral MCT [daily celecoxib (200mg twice daily) and weekly methotrexate (15mg/m(2))] to intravenous single agent cisplatin (IP) (75mg/m(2)) given 3 weekly. Eligible patients had head and neck cancers requiring palliative chemotherapy with ECOG PS 0-2 and adequate organ functions who could not afford cetuximab. The primary end point was progression-free survival.

RESULTS

110 Patients were recruited between July 2011 to May 2013, 57 randomized to the MCT arm and 53 to the IP arm. Patients in the MCT arm had significantly longer PFS (median 101 days, 95% CI: 58.2-143.7 days) compared to the IP arm (median 66 days, 95% CI; 55.8-76.1 days) (p=0.014). The overall survival (OS) was also increased significantly in the MCT arm (median 249 days, 95% CI: 222.5-275.5 days) compared to the IP arm (median 152 days, 95% CI: 104.2-199.8 days) (p=0.02). There were fewer grade 3/4 adverse effects with MCT, which was not significant. (18.9% vs. 31.4%, P=0.14).

CONCLUSION

Oral metronomic chemotherapy has significantly better PFS and OS than single agent platinum in the palliative setting.

Afatinib: first global approval

Afatinib, an irreversible inhibitor of the ErbB family of tyrosine kinases, is under development with Boehringer Ingelheim for the once-daily, oral treatment of cancer. Afatinib downregulates ErbB signalling by covalently binding to epidermal growth factor receptor (EGFR), human epidermal growth factor receptor (HER) 2 and HER4, irreversibly inhibiting tyrosine kinase autophosphorylation. It also inhibits transphosphorylation of HER3. Oral afatinib (Gilotrif™) has been approved in the US for the first-line treatment of patients with metastatic non-small-cell lung cancer (NSCLC) who have tumours with EGFR exon 19 deletions or exon 21 (L858R) substitution mutations as detected by a US FDA-approved test. Afatinib has also been approved in Taiwan for the first-line treatment of patients with EGFR mutation-positive NSCLC. In addition, the European Medicines Agency's Committee for Medicinal Products for Human Use has recommended the approval of afatinib (Giotrif®) for the treatment of patients with locally advanced or metastatic NSCLC with activating EGFR mutations who are EGFR tyrosine kinase inhibitor naïve. Afatinib is also under regulatory review in Canada, Japan and other Asian countries. This article summarizes the milestones in the development of afatinib, leading to this first approval in patients with metastatic NSCLC.

Clinical update on cancer: molecular oncology of head and neck cancer

Head and neck cancers encompass a heterogeneous group of tumours that, in general, are biologically aggressive in nature. These cancers remain difficult to treat and treatment can cause severe, long-term side effects. For patients who are not cured by surgery and/or (chemo)radiotherapy, there are few effective treatment options. Targeted therapies and predictive biomarkers are urgently needed in order to improve the management and minimise the treatment toxicity, and to allow selection of patients who are likely to benefit from both nonselective and targeted therapies. This clinical update aims to provide an insight into the current understanding of the molecular pathogenesis of the disease, and explores the novel therapies under development and in clinical trials.

High-content pSTAT3/1 imaging assays to screen for selective inhibitors of STAT3 pathway activation in head and neck cancer cell lines

The oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) is hyperactivated in most cancers and represents a plausible therapeutic target. In the absence of STAT3-selective small-molecule inhibitors, we sought to develop pSTAT3/1 high-content imaging (HCS) assays to screen for selective inhibitors of STAT3 pathway activation in head and neck squamous cell carcinomas (HNSCC) tumor cell lines. Based on the expression of the interleukin-6 (IL-6)Rα and gp130 subunits of the IL-6 receptor complex and STAT3, we selected the Cal33 HNSCC cell line as our model. After developing image acquisition and analysis procedures, we rigorously investigated the cytokine activation responses to optimize the dynamic ranges of both assays and demonstrated that the pan-Janus kinase inhibitor pyridone 6 nonselectively inhibited pSTAT3 and pSTAT1 activation with 50% inhibition concentrations of 7.19 ± 4.08 and 16.38 ± 8.45 nM, respectively. The optimized pSTAT3 HCS assay performed very well in a pilot screen of 1,726 compounds from the Library of Pharmacologically Active Compounds and the National Institutes of Health clinical collection sets, and we identified 51 inhibitors of IL-6-induced pSTAT3 activation. However, only three of the primary HCS actives selectively inhibited STAT3 compared with STAT1. Our follow-up studies indicated that the nonselective inhibition of cytokine induced pSTAT3 and pSTAT1 activation by G-alpha stimulatory subunit-coupled G-protein-coupled receptor agonists, and forskolin was likely due to cyclic adenosine monophosphate-mediated up-regulation of suppressors of cytokine signaling 3. Azelastine, an H1 receptor antagonist approved for the treatment of seasonal allergic rhinitis, nonallergic vasomotor rhinitis, and ocular conjunctivitis, was subsequently confirmed as a selective inhibitor of IL-6-induced pSTAT3 activation that also reduced the growth of HNSCC cell lines. These data illustrate the power of a chemical biology approach to lead generation that utilizes fully developed and optimized HCS assays as phenotypic screens to interrogate specific signaling pathways.

Alterations in the expression pattern of MTHFR, DHFR, TYMS, and SLC19A1 genes after treatment of laryngeal cancer cells with high and low doses of methotrexate

Inter-individual variations to methotrexate (MTX) outcome have been attributed to different expression profiles of genes related to folate metabolism. To elucidate the mechanisms of variations to MTX outcome, we investigated MTHFR, DHFR, TYMS, and SLC19A1 gene expression profiles by quantifying the mRNA level of the genes involved in folate metabolism to MTX response in laryngeal cancer cell line (HEP-2). For this, three different concentrations of MTX (0.25, 25, and 75 μmol) were added separately in HEP-2 cell line for 24 h at 37 °C. Apoptotis quantification was evaluated with fluorescein isothiocyanate-labeled Bcl-2 by flow cytometry. Real-time quantitative PCR technique was performed by quantification of gene expression with TaqMan® Gene Expression Assay. ANOVA and Bonferroni's post hoc tests were utilized for statistical analysis. The results showed that the numbers of apoptotic HEP-2 cells with 0.25, 25.0, and 75.0 μmol of MTX were 14.57, 77.54, and 91.58%, respectively. We found that the expression levels for MTHFR, DHFR, TYMS, and SLC19A1 genes were increased in cells with 75.0 μmol of MTX (p < 0.05). Moreover, SLC19A1 gene presented lower expression in cells treated with 0.25 μmol of MTX (p < 0.05). In conclusion, our data suggest that MTHFR, DHFR, TYMS, and SLC19A1 genes present increased expression after the highest application of MTX dose in laryngeal cancer cell line. Furthermore, SLC19A1 gene also presents decreased expression after the lowest application of MTX dose in laryngeal cancer cell line. Significant alterations of expression of these studied genes in cell culture model may give support for studies in clinical practice and predict interesting and often novel mechanisms of resistance of MTX chemotherapy.

Differential expression of growth factor receptors and membrane-bound tumor markers for imaging in male and female breast cancer

Introduction

Male breast cancer accounts for 0.5–1% of all breast cancers and is generally diagnosed at higher stage than female breast cancers and therefore might benefit from earlier detection and targeted therapy. Except for HER2 and EGFR, little is known about expression of growth factor receptors in male breast cancer. We therefore investigated expression profiles of growth factor receptors and membrane-bound tumor markers in male breast cancer and gynecomastia, in comparison with female breast cancer.

Methods

Tissue microarrays containing 133 male breast cancer and 32 gynecomastia cases were stained by immunohistochemistry for a panel of membrane-bound targets and compared with data on 266 female breast cancers.

Results

Growth factor receptors were variably expressed in 4.5% (MET) up to 38.5% (IGF1-R) of male breast cancers. Compared to female breast cancer, IGF1-R and carbonic anhydrase 12 (CAXII) were more frequently and CD44v6, MET and FGFR2 less frequently expressed in male breast cancer. Expression of EGFR, HER2, CAIX, and GLUT1 was not significantly different between male and female breast cancer. Further, 48.1% of male breast cancers expressed at least one and 18.0% expressed multiple growth factor receptors. Since individual membrane receptors are expressed in only half of male breast cancers, a panel of membrane markers will be required for molecular imaging strategies to reach sensitivity. A potential panel of markers for molecular imaging, consisting of EGFR, IGF1-R, FGFR2, CD44v6, CAXII, GLUT1, and CD44v6 was positive in 77% of male breast cancers, comparable to female breast cancers.

Conclusions

Expression patterns of growth factor receptors and hypoxia membrane proteins in male breast cancer are different from female breast cancer. For molecular imaging strategies, a putative panel consisting of markers for EGFR, IGF1-R, FGFR2, GLUT1, CAXII, CD44v6 was positive in 77% of cases and might be considered for development of molecular tracers for male breast cancer.

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

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

Head and neck squamous carcinomas with exophytic and endophytic type of growth have the same prognosis after surgery and adjuvant radiotherapy

Head and neck squamous cell carcinomas (HNSCC) are characterized by exophytic or endophytic growth. We hypothesized that the growth pattern predicts outcome and associates with distinct clinical and immunological profiles. Tumors obtained from 60 HNSCC patients treated with surgery and adjuvant radiotherapy were identified as exophytic or endophytic. Recurrence-free survival (RFS) at 42 months was determined. In a subsets of 30 patients (22 exophytic and 8 endophytic) tumor stroma and parenchyma were evaluated for infiltrating CD4(+) and CD8(+) T, dendritic, myeloid and FOXP3(+) regulatory T cells (Treg) and expression of immunosuppressive cytokines by immunohistochemistry. The localization and frequency of positive cells were determined microscopically and analyzed by hierarchical clustering to distinguish exophytic versus endophytic tumors. 34/60 patients had exophytic and 26/60 endophytic tumors. No differences in clinicopathologic data, disease progression or RFS were seen between the two cohorts. Infiltrates of CD3(+)CD8(+) T cells were larger in endophytic than exophytic tumors, while FOXP3(+) Treg, TGF-β(+), IL-10(+), Arg-1(+), CD11b(+) cells were equally prominent in both. FOXP3(+) Treg accumulated in endophytic tumor nests, while the exophytic tumor stroma was enriched in IL-10(+) cells (both at p < 0.05). Hierarchical clustering based on immunophenotyping failed to identify different clusters in these two tumor types. However, CD68(+) macrophages and FOXP3(+) Treg showed a distinct distribution. The HNSCC growth pattern did not predict RFS. Although higher numbers and differences in localization of immunosuppressive cells in endophytic versus exophytic tumors were observed, no significant relationship was established between the growth pattern and the immune profile of infiltrating lymphocytes.