Recent new approaches to the treatment of head and neck cancer

Acute severe hypokalemia caused by treatment of tongue squamous cell carcinoma with docetaxel and cisplatin: A case report

BACKGROUND

The tongue squamous cell carcinoma (TSCC) is an oral malignant tumor arising from the squamous epithelium of the tongue mucosa, characterized by a high malignant degree, invasive growth, early lymph node metastasis, and poor prognosis. Paclitaxel, represented by docetaxel, is now the standard first-line treatment for head and neck squamous cell carcinoma. Docetaxel, which belongs to the class of drugs known as paclitaxel, is an antitumor drug that inhibits cell mitosis and proliferation. Its adverse effects include myelosuppression, hair loss, gastrointestinal reactions, fluid retention, and allergic reactions. However, hypokalemia is rare, most cases are mild or moderate, and severe hypokalemia is seldom reported.

CASE SUMMARY

During chemotherapy with docetaxel and cisplatin, a patient with TSCC developed severe hypokalemia. His potassium level was found to have been reduced to 1.85 mmol/L at the most critical situation. The patient had grade 1 muscle strength in all four limbs and could not perform any action, which was considered to be a sign of severe hypokalemia. Measures taken included intravenous infusion via micro-pump, intravenous injection, and oral potassium supplement, which gradually improved muscle strength and serum potassium levels. The patient survived the critical period of severe hypokalemia after chemotherapy. He was generally in good condition following treatment and discharged in stable condition.

CONCLUSION

Docetaxel may cause severe hypokalemia with hypomagnesemia and the mechanism for this is not yet known to researchers yet. This means that nurses specializing in chemotherapy must exercise a high degree of responsibility, closely observe the patient’s reaction to the anticancer medication, notice any symptoms of adverse effects early. It is necessary to be considerate regarding individual differences between patients when selecting chemotherapy regimens and adhere to the principle of individualized treatment. Following multiple cycles of chemotherapy, patients should be aware of the accumulation of toxic side effects and receive blood tests reviewed within 24 hours of completion. It is essential to monitor electrolyte levels in patients suffering from severe gastrointestinal reactions to avoid complications that may result in death.

MicroRNA-145-5p aggravates cell apoptosis and oxidative stress in tongue squamous cell carcinoma

MicroRNA-145-5p (miR-145-5p) is expressed in a variety of tumors, but the mechanism underlying miR-145-5p in tongue squamous cell carcinoma (TSCC) is not fully understood. Therefore, the present study investigated the role of miR-145-5p in TSCC. miR-145-5p expression levels in TSCC tissues were analyzed via reverse transcription-quantitative PCR. miR-145-5p mimics and inhibitors were transfected into SCC9 and Cal27 cells. The stability and invasion of SCC9 and Cal27 cells were analyzed by performing Transwell assays, while PI and Annexin V were used to detect cell apoptosis. Oxidative stress levels of superoxide dismutase, malondialdehyde and glutathione peroxidase were measured via ELISA. PI3K/AKT signaling pathway-associated protein expression levels were evaluated using western blotting. miR-145-5p was consistently downregulated in TSCC tissues compared with healthy tissues. miR-145-5p overexpression decreased cell stability and invasion, but promoted cell apoptosis and oxidative stress. In addition, PI3K, AKT and phosphorylated-AKT expression levels were significantly diminished. The results indicated that miR-145-5p overexpression inhibited SCC9 and Cal27 cell stability and invasion, promoted SCC9 and Cal27 cell apoptosis and oxidative stress, and inhibited the PI3K/AKT signaling pathway. The results of the present study suggested that miR-145 may serve as a molecular marker of TSCC.

Resident CD34-positive cells contribute to peri-endothelial cells and vascular morphogenesis in salivary gland after irradiation

Salivary gland (SG) hypofunction is a common post-radiotherapy complication. Besides the parenchymal damage after irradiation (IR), there are also effects on mesenchymal stem cells (MSCs) which were shown to contribute to regeneration and repair of damaged tissues by differentiating into stromal cell types or releasing vesicles and soluble factors supporting the healing processes. However, there are no adequate reports about their roles during SG damage and regeneration so far. Using an irradiated SG mouse model, we performed certain immunostainings on tissue sections of submandibular glands at different time points after IR. Immunostaining for CD31 revealed that already one day after IR, vascular impairment was induced at the level of capillaries. In addition, the expression of CD44—a marker of acinar cells—diminished gradually after IR and, by 20 weeks, almost disappeared. In contrast, the number of CD34-positive cells significantly increased 4 weeks after IR and some of the CD34-positive cells were found to reside within the adventitia of arteries and veins. Laser confocal microscopic analyses revealed an accumulation of CD34-positive cells within the area of damaged capillaries where they were in close contact to the CD31-positive endothelial cells. At 4 weeks after IR, a fraction of the CD34-positive cells underwent differentiation into α-SMA-positive cells, which suggests that they may contribute to regeneration of smooth muscle cells and/or pericytes covering the small vessels from the outside. In conclusion, SG-resident CD34-positive cells represent a population of progenitors that could contribute to new vessel formation and/or remodeling of the pre-existing vessels after IR and thus, might be an important player during SG tissue healing.

Transcriptome analysis of tongue cancer based on high‑throughput sequencing

Tongue cancer is one of the most common types of cancer, but its molecular etiology and pathogenesis remain unclear. The aim of the present study was to elucidate the pathogenesis of tongue cancer and investigate novel potential diagnostic and therapeutic targets. Four matched pairs of tongue cancer and paracancerous tissues were collected for RNA sequencing (RNA-Seq), and the differentially expressed genes were analyzed. The RNA-Seq data of tongue cancer tissues were further analyzed using bioinformatics and reverse transcription-quantitative PCR analysis. The sequenced reads were quantified and qualified in accordance with the analysis demands. The transcriptomes of the tongue cancer tissues and paired paracancerous tissues were analyzed, and 1,700 upregulated and 2,249 downregulated genes were identified. Gene Ontology analysis uncovered a significant enrichment in the terms associated with extracellular matrix (ECM) organization, cell adhesion and collagen catabolic processes. Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that these differentially expressed genes were mainly enriched in the focal adhesion pathway, ECM-receptor interaction pathway, phosphoinositide 3-kinase (PI3K)-Akt pathway, and cell adhesion molecules. Comprehensive analyses of the gene tree and pathway network revealed that the majority of cell cycle genes were upregulated, while the majority of the genes associated with intracellular response, cell adhesion and cell differentiation were downregulated. The ECM-receptor interaction, focal adhesion kinase (FAK) and PI3K-Akt pathways were closely associated with one another and held key positions in differential signaling pathways. The ECM-receptor, FAK and PI3K-Akt signaling pathways were found to synergistically promote tongue cancer occurrence and progression, and may serve as potential diagnostic and therapeutic targets for this type of cancer.

Prognostic value of immune checkpoint molecules in head and neck cancer: a meta-analysis

Immune checkpoint molecules are important targets in cancer immunotherapy, but their association with prognosis in patients with head and neck cancer is controversial. In this meta-analysis, we searched for 12 immune checkpoint molecules in the PubMed, Embase and Cochrane Library databases and retrieved 52 studies with 7127 participants. Among the molecules included in the search, indoleamine 2, 3-dioxygenase (IDO), programmed death ligand 1 (PD-L1), and programmed death 1 (PD-1) met the inclusion criteria for further analysis. Higher expression of IDO was associated with poorer overall survival in head and neck cancer patients (P = 0.011), but higher expression of PD-L1 correlated with better overall survival specifically in nasopharyngeal carcinoma patients (P = 0.01). In a sensitivity analysis, higher PD-L1 expression correlated with better progression-free survival (P = 0.043), and was associated with better overall survival in Caucasian subjects (P = 0.02), nasopharyngeal carcinoma patients (P = 0.015), and studies with small sample sizes (P = 0.001). PD-1 had no prognostic significance. There was no publication bias affecting the results. Thus, among the immune checkpoint molecules, IDO and PD-L1 are potential prognostic predictors in head and neck cancer.

Analysıs of gene copy number changes ın head and neck cancer

OBJECTIVE

Chromosomal alterations and copy number changes are frequent events in tumors, leading to amplification of focal regions containing several oncogenes. Gains and losses of several regions have been reported in head and neck cancer (HNC) but the copy number changes of the individual genes located in these regions have not been analyzed so far. In this study we aimed to analyze the copy number variations in patients with HNC.

DESIGN

Prospective study SETTING: University hospital PARTICIPANTS: 50 patients with squamous cell carcinoma of the head and neck METHODS: Copy number changes and amplifications of 22 genes in tumors and matched tissue were analyzed by MLPA which allows simultaneous analysis of gene copy numbers in multiple genetic regions.

RESULTS

Amplifications were observed in 52% and losses were detected in 20% of the samples. Chromosome 8 was found to harbor the most frequent copy number alterations. The most frequently amplified genes were CCND1 and the MED1 genes followed by the MTDH and MYC genes on the long arm and ZNF703 on the short arm of chromosome 8. Amplification of the ZNF703, PRDM14 and MYC genes were highly correlated suggesting that the genes displaying high copy number changes on chromosome 8 collaborate during carcinogenesis.

CONCLUSIONS

The alterations found in our study supports the contribution of gene amplifications and indicate cooperation between certain oncogenes in the pathogenesis of HNSCC. Correlations between amplification of less familiar genes and known oncogenes warrant further investigation. This article is protected by copyright. All rights reserved.

Targeting Toll-like receptor 2 inhibits growth of head and neck squamous cell carcinoma

Infection-driven inflammation has been proposed to be involved in the tumorigenesis of head and neck squamous cell carcinoma (HNSCC). Oral HNSCC is often colonized with microbes such as gram-positive bacteria and yeast, where ligands derived from their wall components have been shown to specifically bind to Toll-like receptor 2 (TLR2). Although TLR2 has been described to be expressed in oral HNSCC, its function has not been well characterized. Here, we show the expression of TLR2 in both HNSCC cell lines and primary patient-derived HNSCC xenograft tumors. Activation of TLR2 with a yeast-derived ligand of TLR2, zymosan, promoted organoid formation in an ex vivo model of tumor growth, while blockade with anti-TLR2 antibodies inhibited organoid formation. Zymosan also induced phosphorylation of ERK and the p65 subunit of NF-κB, which was inhibited in the presence of anti-TLR2 antibodies, indicating that this receptor is functional in HNSCC and that the signaling through these pathways is intact. TLR2 blockade also inhibited growth of human xenografted tumors in immunodeficient mice. In summary, our data show that TLR2 is a functional receptor expressed in human HNSCC that plays a direct pro-tumorigenic role, and that it can be therapeutically targeted with blocking antibodies to reduce tumor growth.

Immune alterations and immunotherapy prospects in head and neck cancer

INTRODUCTION

Several literature sources have suggested that subjects with head and neck squamous cell carcinoma (HNSCC) display significant abnormalities of immunocompetent cells and cytokine secretion. Serious side effects and only a limited success with traditional therapies in HNSCC dictate the need for newer therapies.

AREAS COVERED

This article comprehensively reviews the immune system alterations in HNSCC and the rationale behind various experimental immunotherapies, aiming at keeping this disease under control. Relevant publications were identified through the PubMed database search. The ongoing clinical trials regarding experimental immunotherapy agents in HNSCC were accessed at www.clinicaltrials.gov . The obtained information was thoroughly analyzed and systematized.

EXPERT OPINION

Important and severe immune defects including T-cell dysfunction, cytokine alterations and antigen presentation defects are present in patients with HNSCC. In addition, tumor microenvironment was shown to play a critical role in the HNSCC progression. These discoveries have triggered a growing interest in immunotherapy as a potential treatment strategy for HNSCC. Effective immunotherapy could avoid the toxic side effects plaguing the current management of HNSCC. It is also hoped that immunotherapy will have long-lasting effects due to induction of immunologic memory. Promising directions include nonspecific immune stimulation, targeting specific HNSCC tumor antigens and therapeutic vaccines among others. These new agents may expand the existing therapy options for HNSCC in future.

Simultaneous methylation profiling of tumor suppressor genes in head and neck cancer

Head and neck cancer (HNC) is a common cancer, and its prognosis has not changed during the last decades. Detection of the disease at an early stage is crucial for successful treatment, as early diagnosis can significantly increase the survival rate. Methylation of tumor suppressor genes is an early event in cancer responsible for incorrect gene silencing. Since methylation changes are reversible, they also provide a promising target for therapy. So far, only individual genes have been analyzed for aberrant methylation in HNC. In this study, we analyzed the methylation status of 24 tumor suppressor genes simultaneously by methylation-specific multiplex ligation-dependent probe amplification in matched tumor and normal tissue samples from patients with HNC. CHFR, RARβ, DAPK1, and RASFF1 genes were the most frequently methylated genes in tumor tissue. Eight genes were not methylated in any sample. The methylation frequencies for individual genes ranged from 0% to 19%. Our results indicate that methylation of tumor suppressor genes is not high as previously reported by methylation-specific polymerase chain reaction and is confined to a smaller but significant fraction of the tumors. Whether this group represents a unique entity in the disease spectrum warrants further studies.

The search for new COX-2 inhibitors: a review of 2002 - 2008 patents

BACKGROUND

Two COX isoenzymes are known, COX-1 and COX-2, for which the main inhibitors are the NSAIDs. The common anti-inflammatory drugs (such as aspirin, ibuprofen and naproxen) all act by blocking the action of both the COX-1 and COX-2 enzymes. The COX-2 inhibitors represent a new class of drugs that do not affect COX-1 but selectively block COX-2. This selective action provides the benefits of reducing inflammation without irritating the stomach and cardiovascular effects.

OBJECTIVE

This review focuses on patents published in the field during 2002 - 2008, paying particular attention to promising COX-2 inhibitors.

CONCLUSION

Structural analogues of the COX-2 inhibitors celecoxib and valdecoxib, and novel potential pyridazine, triazole, indole and thione derivatives emerge as promising leads for the treatment of inflammation, pain and other diseases.

Expression of a novel marker, Ubc9, in squamous cell carcinoma of the head and neck

BACKGROUND

Ubiquitin-conjugating enzyme (Ubc9) is a novel enzyme involved in posttranslational modification of cellular proteins. The objective of this study was to determine the expression of Ubc9 in squamous cell carcinoma of the head and neck (SCCHN).

METHODS

SCCHN specimens were stained with anti-Ubc9 antibodies, scored using a semiquantitative method, and statistically analyzed.

RESULTS

Forty-six tumors were stained, 26 of which included adjacent mucosa. Ubc9 was significantly upregulated in the malignant and peritumoral tissues compared with mucosa from normal individuals. In peritumoral tissues, Ubc9 expression was detected in the basal and suprabasal epithelial layers. No Ubc9 was detected in epithelial cells in normal mucosa. These differences in Ubc9 expression were statistically significant (p < .0001). Tumor Ubc9 expression significantly correlated with clinical and pathologic stage.

CONCLUSIONS

Ubc9 is significantly overexpressed in the primary SCCHN tumors and peritumoral mucosa compared with normal epithelial cells. These findings suggest that Ubc9 may play an important role in tumorigenesis and tumor progression of SCCHN.

Sensitivity of salivary glands to radiation: from animal models to therapies

Radiation therapy for head and neck cancer causes significant secondary side-effects in normal salivary glands, resulting in diminished quality of life for these individuals. Salivary glands are exquisitely sensitive to radiation and display acute and chronic responses to radiotherapy. This review will discuss clinical implications of radiosensitivity in normal salivary glands, compare animal models used to investigate radiation-induced salivary gland damage, address therapeutic advances, and project future directions in the field.

Angiogenic growth factors in tissue homogenates of HNSCC: expression pattern, prognostic relevance, and interrelationships

Head and neck squamous cell carcinoma has still a poor prognosis. Since angiogenesis is crucial for tumor growth, a better understanding of the potential clinical relevance as well as the interactions between the numerous proangiogenic growth factors is essential to develop improved therapeutic strategies in these tumors. Expression levels of eight growth factors known to induce angiogenesis (HGF, bFGF, VEGF-A, VEGF-D, PDGF-AB, PDGF-BB, G-CSF, and GM-CSF) were quantitatively measured by ELISA in homogenates of 41 head and neck squamous cell carcinomas. In addition, microvessel density and protein localization of growth factors were assessed by immunohistochemistry. Statistical analysis was performed to assess interrelationships between growth factors analyzed and to correlate protein levels with patient outcome. In 90% of the tissues at least 4/8 growth factors analyzed were detectable. Highest amounts and most frequent expression were found for HGF, bFGF and VEGF-A while PDGF-AB and PDGF-BB were present in two-thirds and G-CSF and GM-CSF in approximately half of the cases. Although there was no significant relation to microvessel density, we identified significant associations for bFGF with HGF and G-CSF as well as of PDGF-AB with those of VEGF-A and PDGF-BB. For the first time we demonstrate that expression levels of HGF as well as that of bFGF and G-CSF in head and neck squamous tumors are negative prognostic factors for patient survival. Our data indicate a network of interrelated and prognostically relevant growth factors in these tumors that have to be taken into consideration when planning an antiangiogenic and antitumor therapy.

P21 Cip1/WAF1 expression is strongly associated with HPV-positive tonsillar carcinoma and a favorable prognosis

Human papillomavirus is involved in the carcinogenesis of tonsillar squamous cell carcinomas. Here, we investigated the expression and the prognostic value of key cell cycle proteins in the pRb and p53 pathways in both human papillomavirus type 16-positive and -negative tonsillar squamous cell carcinomas. Using immunohistochemistry, 77 tonsillar squamous cell carcinomas with known human papillomavirus type 16 status and clinical outcome were analyzed for expression of Ki67, p16(INK4A,) cyclin D1, pRb, p14(ARF), MDM2, p53, p21(Cip1/WAF1), and p27(KIP1). Results were correlated with each other and with clinical and demographic patient data. A total of 35% of tonsillar carcinomas harbored integrated human papillomavirus type 16 DNA and p16(INK4A) overexpression, both being considered essential features for human papillomavirus association. These tumors also showed the overexpression of p14(ARF) (P<0.0001) and p21(Cip1/WAF1) (P=0.001), and downregulation of pRb (P<0.0001) and cyclin D1 (P=0.027) compared with the human papillomavirus-negative cases. Univariate Cox regression analyses revealed a favorable survival rate for non-smokers (P=0.006), as well as for patients with T1-2 tumors (P<0.0001) or tumors showing low expression of cyclin D1 (P=0.028), presence of human papillomavirus and overexpression of p16(INK4A) (P=0.01), p14(ARF) (P=0.02) or p21(Cip1/WAF1) (P=0.004). In multivariate regression analyses, smoking and tumor size, as well as expression of cyclin D1 and p21(Cip1/WAF1), were found to be independent prognostic markers. We conclude that human papillomavirus positivity in tonsillar squamous cell carcinomas strongly correlates with p21(Cip1/WAF1) and p14(ARF) overexpression and downregulation of pRb and cyclin D1. In particular p21(Cip1/WAF1) overexpression is an excellent favorable prognosticator in tonsillar squamous cell carcinomas.

Human head and neck squamous cell carcinoma cells are both targets and effectors for the angiogenic cytokine, VEGF

Former vascular endothelial growth factor (VEGF)-head and neck squamous cell carcinoma (HNSCC) studies have focused on VEGF's contributions toward tumor-associated angiogenesis. Previously, we have shown that HNSCC cells produce high levels of VEGF. We therefore hypothesized that VEGF serves a biphasic role, that is, pro-angiogenic and pro-tumorigenic in HNSCC pathogenesis. Western blots confirmed the presence of VEGF's primary mitogenic receptors, VEGFR-2/KDR and VEGFR-1/Flt-1 in cultured HNSCC cells. Subsequent studies evaluated VEGF's effects on HNSCC intracellular signaling, mitogenesis, invasive capacities, and matrix metalloproteinases (MMPs) activities. Introduction of hrVEGF(165) initiated ROS-mediated intracellular signaling, resulting in kinase activation and phosphorylation of KDR and Erk1/2. As high endogenous VEGF production rendered HNSCC cells refractory to exogenous VEGF's mitogenic effects, siRNA was employed, inhibiting endogenous VEGF production for up to 96 h. Relative to transfection vector matched controls, siRNA treated HNSCC cells showed a significant decrease in proliferation at both 30 and 50 nM siRNA doses. Addition of exogenous hrVEGF(165) (30 and 50 ng/ml) to siRNA-silenced HNSCC cells resulted in dose-dependent increases in cell proliferation. Cell invasion assays showed VEGF is a potent HNSCC chemoattractant and demonstrated that VEGF pre-treatment enhanced invasiveness of HNSCC cells. Conditioned media from VEGF challenged HNSCC cells showed a moderate increase in gelatinase activity. Our results demonstrate, for the first time, that HNSCC cells are both targets and effectors for VEGF. These data introduce the prospect that VEGF targeted therapy has the potential to fulfill both anti-angiogenic and anti-tumorigenic functions.

Frequently methylated tumor suppressor genes in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a very aggressive cancer. In advanced stages, the patient has poor chances of receiving effective treatment, and survival rates are low. To facilitate timely diagnosis and improve treatment, elucidation of early detection markers is crucial. DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable mark. A genome-wide screen using Restriction Landmark Genomic Scanning found a set of genes that are most commonly methylated in head and neck cancers. Five candidate genes: septin 9 (SEPT9), sodium-coupled monocarboxylate transporter 1 (SLC5A8), functional smad-suppressing element on chromosome 18 (FUSSEL18), early B-cell factor 3 (EBF3), and iroquois homeobox 1 (IRX1) were methylated in 27% to 67% of the HNSCC patient samples tested. Furthermore, approximately 50% of the methylated tumor samples shared methylation between two of the five genes (most commonly between EBF3 and IRX1), and 15% shared methylation between three of the five genes. Expression analysis revealed candidate gene down-regulation in 25% to 93% of the HNSCC samples, and 5-aza-2'-deoxycytidine treatment was able to restore expression in at least 2 of 5 HNSCC cell lines for all of the genes tested. Overexpression of the three most frequently down-regulated candidates, SLC5A8, IRX1, and EBF3, validated their tumor suppressor potential by growth curve analysis and colony formation assay. Interestingly, all of the candidates identified may be involved in the transforming growth factor beta signaling pathway, which is often disrupted in HNSCC.

Molecular mechanisms of head and neck cancer

Despite advances in understanding the underlying genetics, squamous cell carcinoma of the head and neck (SCCHN) remains a major health risk and one of the leading causes of mortality in the world. Current standards of treatment have significantly improved long-term survival rates of patients, but second tumors and metastases still remain the most frequent cause of high mortality in SCCHN patients. A better understanding of the underlying genetic mechanisms of SCCHN tumorigenesis will help in developing better diagnostics and, hence, better cures. In this article we will briefly outline the current state of diagnostics and treatment and our understanding of the molecular causes of SCCHN.

Tumor suppressor activity of CCAAT/enhancer binding protein alpha is epigenetically down-regulated in head and neck squamous cell carcinoma

Tumor suppressor CCAAT enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in cell cycle control and cellular differentiation. In a recent study, microarray expression profiling on head and neck squamous cell carcinoma (HNSCC) samples identified significant C/EBPalpha down-regulation, correlating with poor prognosis. However, the mechanisms of C/EBPalpha down-regulation remained elusive. C/EBPalpha has been previously found to provide an antiproliferative role in lung cancer, and our laboratory showed that its down-regulation involves epigenetic mechanisms. This prompted us to investigate the involvement of epigenetics in down-regulating C/EBPalpha in HNSCC. Here, we show that C/EBPalpha is down-regulated in HNSCC by loss of heterozygosity and DNA methylation, but not by gene mutation. We found a consistently methylated upstream regulatory region (-1,399 bp to -1,253 bp in relation to the transcription start site) in 68% of the HNSCC tumor samples, and DNA demethylation using 5-aza-2'-deoxycytidine treatment was able to significantly restore C/EBPalpha mRNA expression in the HNSCC cell lines we tested. In addition, C/EBPalpha overexpression in a HNSCC cell line (SCC22B) revealed its ability to provide tumor suppressor activity in HNSCC in vitro and in vivo. In conclusion, we showed for the first time not only that C/EBPalpha has tumor suppressor activity in HNSCC, but also that it is down-regulated by DNA promoter methylation.

Evidence-based radiation oncology in head and neck squamous cell carcinoma

BACKGROUND AND PURPOSE

Historically, radiation therapy (RT) has been an available treatment option for patients with early resectable head and neck squamous cell carcinoma (HNSCC) and the sole therapy for those with unresectable or inoperable disease. Recently, four noteworthy strategies have emerged for the improvement of therapeutic outcome in the curative treatment of HNSCC: they include the development of altered fractionation radiotherapy, integration of chemotherapy with radiotherapy, incorporation of intensity-modulated radiotherapy and the introduction of targeted biological therapy. These strategies are briefly reviewed in an effort to help interpret evidence-based data and to facilitate clinical-decision making in a clinical context.

MATERIALS AND METHODS

For patients with early stage HNSCC no level 1 study exists in which radiation therapy is compared with conservative surgery for the evaluation of local control or survival. Only evidence from prospective and retrospective cohort studies is available to evaluate the role external radiotherapy and/or brachytherapy currently play in limited disease. For patients with locally advanced HNSCC the recommendations to address the questions about better treatment in resectable and unresectable tumors are based on more than 100 randomized Phase III trials included in six meta-analyses on chemo-radiotherapy and/or altered fractionation. Data from phase II trials and cohort studies help interpret the advances in intensity-modulated radiotherapy.

RESULTS

External radiotherapy and/or brachytherapy are crucial treatment options in patients with early stage HNSCC. For patients with locally advanced HNSCC, where outcome with conventional radiotherapy is poor, meta-analyses and collective data showed that loco-regional control may be improved at high level of evidence by altered fractionation radiotherapy, chemo-radiotherapy with concomitant approach or association of selected hypoxic cell radiosensitizer with radiotherapy. For these patients, overall survival may be improved at high level of evidence by concomitant chemo-radiotherapy or hyperfractionated RT delivered with increased total dose. Also EGFR-inhibitors (cetuximab)-radiotherapy strategy offers at a lower level of evidence better loco-regional control and overall survival than radiotherapy alone. Chemo-radiotherapy programs can achieve an improved larynx-function preservation program without the risk of overall survival reduction, for patients with larynx or hypopharynx tumors who are candidates to radical surgery followed by radiotherapy. Recently, strong evidence for an improved outcome for high-risk resected patients has been shown by the use of adjuvant concomitant chemo-radiotherapy. Despite improved results, a higher severe toxicity has been largely evidenced with concomitant chemo-radiotherapy by reducing the gain in the therapeutic index with new treatment strategies. Three-dimensional conformal radiotherapy is the minimal standard of technique in HNSCC: however, as advances are promising, intensity-modulated radiotherapy should be largely implemented.

CONCLUSIONS

Stepwise improvements in HNSCC non-surgical therapy have shown favorable impact on loco-regional control and overall survival. However, despite hundreds of clinical trials in patients with advanced disease, there is no absolute consensus about patient selection for altered fractionation regimens, type of chemo-radiotherapy association, radiation or chemotherapy dose schedule. Nevertheless, many well-conducted clinical studies have expanded therapy options besides standard radiotherapy and have contributed to defining the evolving standard of care for patients with HNSCC.

Role of cytokines in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma is one of the most frequent cancers and standard treatment has only marginally improved the 5-year survival rate of patients with this disease in the last few decades. It is supposed that cytokine alterations in immune, inflammatory and angiogenetic regulatory routes within the head and neck squamous cell carcinoma microenvironment play a critical role in tumor aggressiveness, its response to chemo- and radiation therapies, as well as the development of immune escape mechanisms.