Poor prognosis in human papillomavirus-positive oropharyngeal squamous cell carcinomas that overexpress hypoxia inducible factor-1α

Development of 18F-Fluoromisonidazole Hypoxia PET/CT Diagnostic Interpretation Criteria and Validation of Interreader Reliability, Reproducibility, and Performance

Tumor hypoxia, an integral biomarker to guide radiotherapy, can be imaged with 18F-fluoromisonidazole (18F-FMISO) hypoxia PET. One major obstacle to its broader application is the lack of standardized interpretation criteria. We sought to develop and validate practical interpretation criteria and a dedicated training protocol for nuclear medicine physicians to interpret 18F-FMISO hypoxia PET. Methods: We randomly selected 123 patients with human papillomavirus-positive oropharyngeal cancer enrolled in a phase II trial who underwent 123 18F-FDG PET/CT and 134 18F-FMISO PET/CT scans. Four independent nuclear medicine physicians with no 18F-FMISO experience read the scans. Interpretation by a fifth nuclear medicine physician with over 2 decades of 18F-FMISO experience was the reference standard. Performance was evaluated after initial instruction and subsequent dedicated training. Scans were considered positive for hypoxia by visual assessment if 18F-FMISO uptake was greater than floor-of-mouth uptake. Additionally, SUVmax was determined to evaluate whether quantitative assessment using tumor-to-background ratios could be helpful to define hypoxia positivity. Results: Visual assessment produced a mean sensitivity and specificity of 77.3% and 80.9%, with fair interreader agreement (κ = 0.34), after initial instruction. After dedicated training, mean sensitivity and specificity improved to 97.6% and 86.9%, with almost perfect agreement (κ = 0.86). Quantitative assessment with an estimated best SUVmax ratio threshold of more than 1.2 to define hypoxia positivity produced a mean sensitivity and specificity of 56.8% and 95.9%, respectively, with substantial interreader agreement (κ = 0.66), after initial instruction. After dedicated training, mean sensitivity improved to 89.6% whereas mean specificity remained high at 95.3%, with near-perfect interreader agreement (κ = 0.86). Conclusion: Nuclear medicine physicians without 18F-FMISO hypoxia PET reading experience demonstrate much improved interreader agreement with dedicated training using specific interpretation criteria.

Advances and residual knowledge gaps in the neck management of head and neck squamous cell carcinoma patients with advanced nodal disease undergoing definitive (chemo)radiotherapy for their primary

PURPOSE

Substantial changes have been made in the neck management of patients with head and neck squamous cell carcinomas (HNSCC) in the past century. These have been fostered by changes in cancer epidemiology and technological progress in imaging, surgery, or radiotherapy, as well as disruptive concepts in oncology. We aimed to review changes in nodal management, with a focus on HNSCC patients with nodal involvement (cN+) undergoing (chemo)radiotherapy.

METHODS

A narrative review was conducted to review current advances and address knowledge gaps in the multidisciplinary management of the cN+ neck in the context of (chemo)radiotherapy.

RESULTS

Metastatic neck nodes are associated with poorer prognosis and poorer response to radiotherapy, and have therefore been systematically treated by surgery. Radical neck dissection (ND) has gradually evolved toward more personalized and less morbid approaches, i.e., from functional to selective ND. Omission of ND has been made feasible by use of positron-emission tomography/computed tomography to monitor the radiation response in cN+ patients. Human papillomavirus-driven oropharyngeal cancers and their cystic nodes have shown dramatically better prognosis than tobacco-related cancers, justifying a specific prognostic classification (AJCC) creation. Finally, considering the role of lymph nodes in anti-tumor immunity, de-escalation of ND and prophylactic nodal irradiation in combination are intense areas of investigation. However, the management of bulky cN3 disease remains an issue, as aggressive multidisciplinary strategies or innovative combined treatments have not yet significantly improved their prognosis.

CONCLUSION

Personalized neck management is an increasingly important aspect of the overall therapeutic strategies in cN+ HNSCC.

Aspartate-β-hydroxylase and hypoxia marker expression in head and neck carcinomas: implications for HPV-associated tumors

BACKGROUND

A proportion of head and neck carcinomas (HNSCCs) are induced by high-risk human papillomaviruses (HPVs) and are associated with better patient outcomes compared to patients with HNSCCs related to tobacco and alcohol abuse. In the microenvironment of solid tumors, including HNSCCs, oxygen levels are often reduced, and a hypoxic state is induced. This can lead to a poor treatment response and a worse patient prognosis. One of the hypoxia-responsive genes is aspartate-β-hydroxylase (ASPH), whose activity promotes the growth, invasiveness, and metastasis of many types of solid tumors.

METHODS

In our study, HNSCC samples were analyzed for the expression of ASPH and selected endogenous hypoxia markers by real-time PCR and/or multiplex fluorescence immunohistochemistry.

RESULTS

Except for the EPAS1 gene, which had higher mRNA expression in the HPV-negative group of HNSCC (p < 0.05), we found no other differences in the expression of the tested genes that were related to HPV status. On the contrary, a statistically significantly higher number of cells producing ASPH (p < 0.0001), HIF1A (p < 0.0001), GLUT1 (p < 0.0001), and MMP13 (p < 0.05) proteins were detected in the HPV-positive tumor group than in the HPV-negative sample group. All the evaluated markers, except for MMP9/13, were more abundant in the tumor parenchyma than in the tumor stroma. The Cox proportional hazard models showed that increased numbers of cells with GLUT1 and HIF1A protein expression were positive prognostic markers for overall and disease-specific survival in patients independent of HPV tumor status.

CONCLUSION

The study examined HNSCC samples and found that elevated ASPH and hypoxia marker proteins, typically associated with poor prognosis, may actually indicate active HPV infection, the strongest prognostic factor in HNSCC patients. In cases where HPV status is uncertain, increased expression of HIF1A and GLUT1 can serve as positive prognostic factors.

PPARα Agonism Enhances Immune Response to Radiotherapy While Dietary Oleic Acid Results in Counteraction

PURPOSE

Head and neck cancer (HNC) improvements are stagnant, even with advances in immunotherapy. Our previous clinical trial data show that altered fatty acid (FA) metabolism correlates with outcome. We hypothesized that pharmacologic and dietary modulation of FA catabolism will affect therapeutic efficacy.

EXPERIMENTAL DESIGN

We performed in vivo and in vitro experiments using PPARα agonism with fenofibrate (FF) or high oleic acid diets (OAD) with radiotherapy, generating metabolomic, proteomic, stable isotope tracing, extracellular flux analysis, and flow-cytometric data to investigate these alterations.

RESULTS

FF improved antitumor efficacy of high dose per fraction radiotherapy in HNC murine models, whereas the OAD reversed this effect. FF-treated mice on the control diet had evidence of increased FA catabolism. Stable isotope tracing showed less glycolytic utilization by ex vivo CD8+ T cells. Improved efficacy correlated with intratumoral alterations in eicosanoid metabolism and downregulated mTOR and CD36.

CONCLUSIONS

Metabolic intervention with increased FA catabolism improves the efficacy of HNC therapy and enhances antitumoral immune response.

Hypoxia-Directed Treatment of Human Papillomavirus-Related Oropharyngeal Carcinoma

PURPOSE

Standard curative-intent chemoradiotherapy for human papillomavirus (HPV)-related oropharyngeal carcinoma results in significant toxicity. Since hypoxic tumors are radioresistant, we posited that the aerobic state of a tumor could identify patients eligible for de-escalation of chemoradiotherapy while maintaining treatment efficacy.

METHODS

We enrolled patients with HPV-related oropharyngeal carcinoma to receive de-escalated definitive chemoradiotherapy in a phase II study (ClinicalTrials.gov identifier: NCT03323463). Patients first underwent surgical removal of disease at their primary site, but not of gross disease in the neck. A baseline 18F-fluoromisonidazole positron emission tomography scan was used to measure tumor hypoxia and was repeated 1-2 weeks intratreatment. Patients with nonhypoxic tumors received 30 Gy (3 weeks) with chemotherapy, whereas those with hypoxic tumors received standard chemoradiotherapy to 70 Gy (7 weeks). The primary objective was achieving a 2-year locoregional control (LRC) of 95% with a 7% noninferiority margin.

RESULTS

One hundred fifty-eight patients with T0-2/N1-N2c were enrolled, of which 152 patients were eligible for analyses. Of these, 128 patients met criteria for 30 Gy and 24 patients received 70 Gy. The 2-year LRC was 94.7% (95% CI, 89.8 to 97.7), meeting our primary objective. With a median follow-up time of 38.3 (range, 22.1-58.4) months, the 2-year progression-free survival (PFS) and overall survival (OS) rates were 94% and 100%, respectively, for the 30-Gy cohort. The 70-Gy cohort had similar 2-year PFS and OS rates at 96% and 96%, respectively. Acute grade 3-4 adverse events were more common in 70 Gy versus 30 Gy (58.3% v 32%; P = .02). Late grade 3-4 adverse events only occurred in the 70-Gy cohort, in which 4.5% complained of late dysphagia.

CONCLUSION

Tumor hypoxia is a promising approach to direct dosing of curative-intent chemoradiotherapy for HPV-related carcinomas with preserved efficacy and substantially reduced toxicity that requires further investigation.

Clinical and prognostic significance analysis of glycolysis-related genes in HNSCC

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) represents one of the most malignant cancers worldwide, with poor survival. Experimental evidence implies that glycolysis/hypoxia is associated with HNSCC. In this study, we aimed to construct a novel glycolysis-/hypoxia-related gene (GHRG) signature for survival prediction of HNSCC.

METHODS

A multistage screening strategy was used to establish the GHRG prognostic model by univariate/least absolute shrinkage and selection operator (LASSO)/step multivariate Cox regressions from The Cancer Genome Atlas cohort. A nomogram was constructed to quantify the survival probability. Correlations between risk score and immune infiltration and chemotherapy sensitivity were explored.

RESULTS

We established a 12-GHRG mRNA signature to predict the prognosis in HNSCC patients. Patients in the high-risk score group had a much worse prognosis. The predictive power of the model was validated by external HNSCC cohorts, and the model was identified as an independent factor for survival prediction. Immune infiltration analysis showed that the high-risk score group had an immunosuppressive microenvironment. Finally, the model was effective in predicting chemotherapeutic sensitivity.

CONCLUSIONS

Our study demonstrated that the GHRG model is a robust prognostic tool for survival prediction of HNSCC. Findings of this work provide novel insights for immune infiltration and chemotherapy of HNSCC, and may be applied clinically to guide therapeutic strategies.

The Effects of Gross Cranial Nerve Invasion on Oncologic Outcomes in Patients with HPV(+)OPSCC

OBJECTIVES

This study examines oncologic outcomes in patients with HPV-related oropharyngeal squamous cell carcinoma (HPV(+)OPSCC) who had evidence of gross cranial nerve invasion (CNI) identified at the time of surgery.

STUDY DESIGN

Retrospective cohort study comparing demographics, clinical features, and outcomes of HPV(+)OPSCC patients with and without gross CNI.

METHODS

Patients with biopsy proven HPV(+)OPSCC involving the base of tongue, tonsil, or unknown primary site, who underwent surgery as a part of their treatment between 1/1/2006-12/31/2020 (n = 874), were included in this study. Gross CNI was identified during operative intervention (n = 36). Statistical analyses were performed using SAS version 9.4 and R version 3.6.2. P-values <0.05 were considered statistically significant.

RESULTS

HPV(+)OPSCC patients with gross CNI were nearly 5 times as likely to suffer death by cancer (HR = 5.41, 95% CI 2.51 to 11.67, p < 0.0001), over 4 times as likely to see disease progression (HR = 4.25, 95% CI 2.31 to 7.84, p < 0.0001), and nearly 5 times as likely to experience metastasis (HR = 4.46, 95% CI 2.20 to 9.06, p < 0.0001) when compared to patients without CNI. Patients with gross CNI had significantly lower overall survival, cancer-specific survival, progression-free survival, and distant-metastasis free survival (p < 0.0001). Patients with gross CNI were significantly more likely to present with higher clinical N stage, higher pathological N stage and extracapsular spread than patients without gross CNI.

CONCLUSIONS

Our findings indicate that the presence of CNI is associated with significantly poorer oncologic outcomes in HPV(+)OPSCC patients.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:170-177, 2024.

Diagnostic, Prognostic, and Therapeutic Role for Angiogenesis Markers in Head and Neck Squamous Cell Carcinoma: A Narrative Review

Despite refinements to diagnostic and therapeutic approaches over the last two decades, the outcome of patients with head and neck squamous cell carcinoma (HNSCC) has not shown substantial improvements, especially regarding those with advanced-stage disease. Angiogenesis is believed to be a turning point in the development of solid tumors, being a premise for mass growth and potential distant dissemination. Cancer-induced angiogenesis is a result of increased expression of angiogenic factors, decreased expression of anti-angiogenic factors, or a combination of both. The assessment of angiogenesis has also emerged as a potentially useful biological prognostic and predictive factor in HNSCC. The aim of this review is to assess the level of current knowledge on the neo-angiogenesis markers involved in the biology, behavior, and prognosis of HNSCC. A search (between 1 January 2012 and 10 October 2022) was run in PubMed, Scopus, and Web of Science electronic databases. After full-text screening and application of inclusion/exclusion criteria, 84 articles are included. The current knowledge and debate on angiogenesis in HNSCC presented in the eligible articles are stratified as follows: (i) diagnostic markers; (ii) prognostic markers; (iii) predictive markers; and (iv) markers with a potential therapeutic role. Angiogenesis is a biological and pathological indicator of malignancies progression and has negative implications in prognosis of some solid tumors; several signals capable of tripping the "angiogenic switch" have also been identified in HNSCC. Although several studies suggested that antiangiogenic agents might be a valuable adjunct to conventional chemo-radiation of HNSCC, their long-term therapeutic value remains uncertain. Further investigations are required on combinations of antiangiogenic agents with conventional chemotherapeutic ones, immunotherapeutic and molecularly targeted agents in HNSCC. Additional data are necessary to pinpoint which patients could benefit most from these treatments.

Prognostic histological markers in oral tongue squamous cell carcinoma patients treated with (chemo)radiotherapy

Treatment of oral tongue squamous cell carcinoma (OTSCC) frequently includes surgery with postoperative radiotherapy (RT) or chemoradiotherapy (CRT). Resistance to RT or CRT remains a major clinical challenge and highlights the need to identify predictive markers for it. We included 71 OTSCC patients treated with surgery combined with RT or CRT. We evaluated the association between tumor budding, tumor-stroma ratio (TSR), depth of invasion (DOI), tumor-infiltrating lymphocytes (TILs), hypoxia-inducible factor-1alpha (HIF-1alpha) expression, octamer-binding transcription factor 4 (OCT4) expression, high-endothelial venules (HEVs), and disease-free survival (DFS) using uni- and multivariate analyses. No significant association was observed between the different histological and molecular markers (TSR, DOI, TILs, HEV, HIF-1alph, OCT4) and DFS. However, an associative trend between DOI, budding, and DFS was noted. Further studies with larger cohorts are needed to explore the prognostic value of DOI and budding for OTSCC patients treated with postoperative RT or CRT.

Establishment and validation of a redox-related long non-coding RNAs prognostic signature in head and neck squamous cell carcinoma

Reduction and oxidation (redox) reactions occur in living organisms as part of normal cellular metabolism. Here, we established a novel redox-related long non-coding RNAs (rrlncRNAs) signature to predict the prognosis and therapeutic response in Head and neck squamous cell carcinoma (HNSCC). The expression profile and clinical information were obtained from the TCGA project. In total, 10 differently expressed rrlncRNAs associated with prognosis were identified and involved in a prognostic risk score signature by the least absolute shrinkage and selection operator penalized Cox analysis. The area under the receiver operating characteristic curves of the survival rates predicted by the rrlncRNAs signature over one, two, and three years were found to be 0.651, 0.670, and 0.679. Following the completion of the Kaplan-Meier survival study, we discovered that the lower-risk cohort exhibited a much longer overall survival period in contrast with the higher-risk cohort. Univariate and multivariable Cox regression analyses demonstrated that the risk score independently served as a significant predictive factor. GO annotation and KEGG pathway analyses illustrated that the rrlncRNAs signature was strongly associated with immune-related functions as well as signaling pathways. The tumor-infiltrating immune cells, tumor microenvironment, immune-related functions, HLA gene family expression, immune checkpoint genes expression, and somatic variants differed substantially between the low- and high-risk cohorts. Moreover, patients in low-risk group were predicted to present a favorable immunotherapy responsiveness, while in contrast, the high-risk group patients might have a stronger sensitivity to "docetaxel". According to our findings, the rrlncRNAs signature showed an excellent prognosis predictive value and might indicate therapeutic response to immunotherapy in HNSCC.

Defining the optimal threshold and prognostic utility of pre-treatment hemoglobin level as a biomarker for survival outcomes in head and neck cancer patients receiving chemoradiation

OBJECTIVES

We sought to define the optimal threshold for anemia in North American head and neck cancer patients and evaluate its role as a prognostic biomarker.

MATERIALS AND METHODS

A single-institution database was queried for patients with head and neck cancer who underwent chemoradiation from January 2005 to April 2021. An optimal threshold of hemoglobin (Hgb) level was defined based on maximum log-rank test statistic. Cox multivariable analysis (MVA), Kaplan-Meier, and propensity score matching were performed to evaluate treatment outcomes.

RESULTS

A total of 496 patients were identified. Threshold for Hgb was determined to be 11.4 for both overall survival (OS) and progression-free survival (PFS). Low Hgb was associated with worse OS (adjusted hazards ratio [aHR] 2.41, 95 % confidence interval [CI] 1.53-3.80, p < 0.001) and PFS (aHR 2.01, 95 % CI 1.30-3.11, p = 0.002). Similar findings were observed among 39 matched pairs for OS (5-year OS 22.3 % vs 49.0 %; HR 2.22, 95 % CI 1.23-4.03, p = 0.008) and PFS (5-year PFS 24.3 % vs 39.1 %; HR 1.78, 95 % CI 1.02-3.12, p = 0.04). Among those with HPV-negative tumors, low Hgb was associated with worse OS (aHR 13.90, 95 % CI 4.66-41.44, p < 0.001) and PFS (aHR 5.24, 95 % CI 2.09-13.18, p < 0.001). However, among those with HPV-positive tumors, low Hgb was not associated with both OS (aHR 1.75, 95 % CI 0.60-5.09, p = 0.31) and PFS (aHR 1.13, 95 % CI 0.41-3.14, p = 0.82).

CONCLUSION AND RELEVANCE

Low Hgb below 11.4 was an independent adverse prognostic factor for worse survival. It was also prognostic among patients with HPV-negative tumors, but not for HPV-positive tumors.

Radioimmunotherapy in HPV-Associated Head and Neck Squamous Cell Carcinoma

HPV-associated head and neck squamous cell carcinoma (HNSCC) is a cancer entity with unique biological and clinical characteristics that requires more personalized treatment strategies. As the backbone of conventional therapeutics, radiation is now harnessed to synergize with immunotherapy in multiple malignancies. Accumulating preclinical and clinical data have suggested the potential of radioimmunotherapy in eliciting local and systemic anti-tumor response via direct killing of tumor cells and immunogenic cell death. However, this effect remains uncertain in HPV-associated HNSCC. Owing to its intrinsic radiosensitivity and distinct tumor microenvironment, HPV-associated HNSCC may represent a good candidate for radioimmunotherapy. In this review, we provide a detailed illustration of the biology, the genomic features, and immune landscapes of HPV-associated HNSCC that support the synergism between radiation and immune agents. The interaction between radiotherapy and immunotherapy is described. We also highlight the present evidence as well as ongoing trials using different combination strategies in the recurrent/metastatic or definitive settings. In addition, we have summarized the challenges and outlook for future trial design, with special emphasis on radiotherapy optimization and novel therapeutic options to incorporate.

Effect of Glut-1 and HIF-1α double knockout by CRISPR/CAS9 on radiosensitivity in laryngeal carcinoma via the PI3K/Akt/mTOR pathway

Hypoxic resistance is the main obstacle to radiotherapy for laryngeal carcinoma. Our previous study indicated that hypoxia-inducible factor 1α (HIF-1α) and glucose transporter 1 (Glut-1) double knockout reduced tumour biological behaviour in laryngeal carcinoma cells. However, their radioresistance mechanism remains unclear. In this study, cell viability was determined by CCK8 assay. Glucose uptake capability was evaluated by measurement of ¹⁸ F-fluorodeoxyglucose radioactivity. A tumour xenograft model was established by subcutaneous injection of Tu212 cells. Tumour histopathology was determined by haematoxylin and eosin staining, immunohistochemical staining, and TUNEL assays. Signalling transduction was evaluated by Western blotting. We found that hypoxia induced radioresistance in Tu212 cells accompanied by increased glucose uptake capability and activation of the PI3K/Akt/mTOR pathway. Inhibition of PI3K/Akt/mTOR activity abolished hypoxia-induced radioresistance and glucose absorption. Mechanistic analysis revealed that hypoxia promoted higher expressions of HIF-1α and Glut-1. Moreover, the PI3K/Akt/mTOR pathway was a positive mediator of HIF-1α and/or Glut-1 in the presence of irradiation. HIF-1α and/or Glut-1 knockout significantly reduced cell viability, glucose uptake and PI3K/Akt/mTOR activity, all of which were induced by hypoxia in the presence of irradiation. In vivo analysis showed that knockout of HIF-1α and/or Glut-1 also inhibited tumour growth by promoting cell apoptosis, more robustly compared with the PI3K inhibitor wortmannin, particularly in tumours with knockout of both HIF-1α and Glut-1. HIF-1α and/or Glut-1 knockout also abrogated PI3K/Akt/mTOR signalling transduction in tumour tissues, in a manner similar to wortmannin. HIF-1α and/or Glut-1 knockout facilitated radiosensitivity in laryngeal carcinoma Tu212 cells by regulation of the PI3K/Akt/mTOR pathway.

Correlation and colocalization of HIF-1α and pimonidazole staining for hypoxia in laryngeal squamous cell carcinomas: A digital, single-cell-based analysis

OBJECTIVE

Tumor hypoxia results in worse local control and patient survival. We performed a digital, single-cell-based analysis to compare two biomarkers for hypoxia (hypoxia-inducible factor 1-alpha [HIF-1α] and pimonidazole [PIMO]) and their effect on outcome in laryngeal cancer patients treated with accelerated radiotherapy with or without carbogen breathing and nicotinamide (AR versus ARCON).

MATERIALS AND METHODS

Immunohistochemical staining was performed for HIF-1α and PIMO in consecutive sections of 44 laryngeal cancer patients randomized between AR and ARCON. HIF-1α expression and PIMO-binding were correlated using digital image analysis in QuPath. High-density areas for each biomarker were automatically annotated and staining overlap was analyzed. Kaplan-Meier survival analyses for local control, regional control and disease-free survival were performed to predict a response benefit of ARCON over AR alone for each biomarker.

RESULTS

106 Tissue fragments of 44 patients were analyzed. A weak, significant positive correlation was observed between HIF-1α and PIMO positivity on fragment level, but not on patient level. A moderate strength correlation (r = 0.705, p < 0.001) was observed between the number of high-density staining areas for both biomarkers. Staining overlap was poor. HIF-1α expression, PIMO-binding or a combination could not predict a response benefit of ARCON over AR.

CONCLUSION

Digital image analysis to compare positive cell fractions and staining overlap between two hypoxia biomarkers using open-source software is feasible. Our results highlight that there are distinct differences between HIF-1α and PIMO as hypoxia biomarkers and therefore suggest co-existence of different forms of hypoxia within a single tumor.

More than a Bubble: Extracellular Vesicle microRNAs in Head and Neck Squamous Cell Carcinoma

Simple Summary

Head and neck squamous cell carcinoma (HNSCC) is an aggressive and lethal disease. Despite diagnostic and therapeutic advances, the overall survival of patients with advanced HNSCC remains poor. Recently, microRNAs in extracellular vesicles (EV-miRNAs) have been proposed as essential regulatory molecules involved in HNSCC. EV-miRNAs may serve as disease biomarkers and represent a novel therapeutic target. This review summarizes the current understanding of the role of EV-miRNAs in HNSCC as well as their potential future clinical applications.

Abstract

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that play a pivotal regulatory role in a broad variety of biological processes. Dysregulation of miRNAs is associated with several human diseases, particularly cancer. Extracellular vesicles (EVs) are crucial components in intercellular communication. As part of the cargo of EVs, miRNAs are involved in EV-mediated cell-to-cell interactions, including promotion or suppression of tumor development. The knowledge on the molecular mechanisms and clinical importance of EV-miRNAs in head and neck squamous cell carcinoma (HNSCC) has rapidly grown over the past years. In the present review, the current understanding regarding the effect of EV-miRNAs on HNSCC tumorigenesis is summarized, which includes effects on tumor proliferation, angiogenesis, invasion and metastasis, the tumor microenvironment, immune modulation, and treatment resistance. EV-miRNA-based biomarkers in liquid biopsies such as blood and saliva may open up new possibilities for employing EV-miRNAs for screening and early diagnostics as well as disease monitoring. Future perspectives include the promise of EV-miRNAs as a novel therapeutic target.

Hypoxia induces radioresistance, epithelial‑mesenchymal transition, cancer stem cell‑like phenotype and changes in genes possessing multiple biological functions in head and neck squamous cell carcinoma

Hypoxia has been linked with increased resistance to treatment in various solid tumors, including head and neck squamous cell carcinoma (HNSCC). The aim of the present study was to identify genes involved in hypoxia‑mediated responses to radiotherapy in HNSCC. A total of three HNSCC cell lines with an epithelial phenotype were selected for this study and cultured under normoxic (21% O₂) or hypoxic (1% O₂) conditions. The sensitivity of the HNSCC cells to radiotherapy was assessed by a crystal violet assay. Western blotting (for protein expression), cDNA microarrays and reverse transcription‑quantitative PCR (for gene expression) were also applied. Small interfering RNA silencing was used to knock down target genes. The results revealed that hypoxia negatively affected the response of HNSCC cells to radiotherapy. Of note, increased levels of N‑cadherin, vimentin and fibronectin, as well as stem cell‑associated transcription factors, were observed under hypoxia. The microarray analysis revealed a number of hypoxia‑regulated genes that were involved in multiple biological functions. However, downregulation of hypoxia‑regulated genes did not affect sensitivity to radiotherapy of the investigated cell lines. Taken together, the present findings indicated several important pathways and genes that were involved in hypoxia and radiotherapy resistance. It is hypothesized that panels of reported hypoxia‑regulated genes may be useful for the prediction of radiotherapy responses in patients with HNSCC.

Hypoxia and Its Influence on Radiotherapy Response of HPV-Positive and HPV-Negative Head and Neck Cancer

Head and neck squamous cancers are a heterogeneous group of cancers that arise from the upper aerodigestive tract. Etiologically, these tumors are linked to alcohol/tobacco abuse and infections with high-risk human papillomavirus (HPV). HPV-positive HNSCCs are characterized by a different biology and also demonstrate better therapy response and survival compared to alcohol/tobacco-related HNSCCs. Despite this advantageous therapy response and the clear biological differences, all locally advanced HNSCCs are treated with the same chemo-radiotherapy schedules. Although we have a better understanding of the biology of both groups of HNSCC, the biological factors associated with the increased radiotherapy response are still unclear. Hypoxia, i.e., low oxygen levels because of an imbalance between oxygen demand and supply, is an important biological factor associated with radiotherapy response and has been linked with HPV infections. In this review, we discuss the effects of hypoxia on radiotherapy response, on the tumor biology, and the tumor microenvironment of HPV-positive and HPV-negative HNSCCs by pointing out the differences between these two tumor types. In addition, we provide an overview of the current strategies to detect and target hypoxia.

SOHLH2 Suppresses Angiogenesis by Downregulating HIF1α Expression in Breast Cancer

SOHLH2 has been demonstrated the downregulation in various cancers and the involvement in tumor growth and metastasis. However, the function of SOHLH2 on tumor angiogenesis and the underlying molecular mechanisms have not been interrogated. IHC staining results revealed that SOHLH2 was negatively associated with microvessel density (MVD), tumor size, histology grade, and metastasis. Overexpression of SOHLH2 inhibited the angiogenic behavior of human umbilical vein endothelial cells (HUVEC) by a tumor cell-mediated paracrine signal, while knockdown of SOHLH2 promoted HUVEC angiogenic behavior. Ectopic SOHLH2 expression remarkably suppressed tumor growth and MVD in xenograft tumors, downregulated the expression of hypoxia inducible factor-1 alpha (HIF1α)-mediated proangiogenic genes in vivo and in vitro, while knockdown of SOHLH2 had an opposite result. Furthermore, we found that upregulation of HIF1α reversed SOHLH2-induced suppression of breast cancer angiogenesis, while KC7F2, the inhibitor of HIF1α, could attenuate the promotion of angiogenesis by SOHLH2 silencing. Using Chromatin immunoprecipitation and luciferase reporter assays, we validated that SOHLH2 could directly bind to HIF1α promoter and repress its transcriptional activity. Collectively, SOHLH2 suppresses breast cancer angiogenesis by downregulating HIF1α transcription and may be a potential biomarker for anti-angiogenesis therapy. IMPLICATIONS: SOHLH2 directly represses HIF1α-mediated angiogenesis and serves as an important inhibitor of angiogenesis in breast cancer.

Prognostic value of glycolysis markers in head and neck squamous cell carcinoma: a meta-analysis

Glycolysis markers including glucose transporter 1 (GLUT1), monocarboxylate transporter 4 (MCT4), hexokinase 2 (HK2), pyruvate kinase M2 (PKM2) and glucose transporter 4 (GLUT4) play vital roles in head and neck squamous cell carcinoma (HNSCC). However, their prognostic value in HNSCC is still controversial. In this meta-analysis, we searched the PubMed, Web of Science and Cochrane Library databases and included thirty-seven studies (3272 patients) that met the inclusion criteria. Higher expression levels of the glycolysis markers in tumor tissues correlated with poorer overall survival (OS; P < 0.001), disease-free survival (DFS; P = 0.03) and recurrence-free survival (RFS; P < 0.001) of HNSCC patients. Subgroup and sensitivity analyses demonstrated that higher expression levels of GLUT1 (P < 0.001), MCT4 (P = 0.002), HK2 (P = 0.002) and PKM2 (P < 0.001) correlated with poorer OS among HNSCC patients. Higher expression of MCT4 (P < 0.001) and PKM2 (P = 0.008) predicted poorer DFS among HNSCC patients. However, GLUT4 expression levels did not associate with clinical outcomes in HNSCC patients. These results demonstrate that glycolysis markers, such as GLUT1, MCT4, HK2 and PKM2, are potential prognostic predictors and therapeutic targets in HNSCC.

Precision Radiotherapy: Reduction in Radiation for Oropharyngeal Cancer in the 30 ROC Trial

BACKGROUND

Patients with human papillomavirus-related oropharyngeal cancers have excellent outcomes but experience clinically significant toxicities when treated with standard chemoradiotherapy (70 Gy). We hypothesized that functional imaging could identify patients who could be safely deescalated to 30 Gy of radiotherapy.

METHODS

In 19 patients, pre- and intratreatment dynamic fluorine-18-labeled fluoromisonidazole positron emission tomography (PET) was used to assess tumor hypoxia. Patients without hypoxia at baseline or intratreatment received 30 Gy; patients with persistent hypoxia received 70 Gy. Neck dissection was performed at 4 months in deescalated patients to assess pathologic response. Magnetic resonance imaging (weekly), circulating plasma cell-free DNA, RNA-sequencing, and whole-genome sequencing (WGS) were performed to identify potential molecular determinants of response. Samples from an independent prospective study were obtained to reproduce molecular findings. All statistical tests were 2-sided.

RESULTS

Fifteen of 19 patients had no hypoxia on baseline PET or resolution on intratreatment PET and were deescalated to 30 Gy. Of these 15 patients, 11 had a pathologic complete response. Two-year locoregional control and overall survival were 94.4% (95% confidence interval = 84.4% to 100%) and 94.7% (95% confidence interval = 85.2% to 100%), respectively. No acute grade 3 radiation-related toxicities were observed. Microenvironmental features on serial imaging correlated better with pathologic response than tumor burden metrics or circulating plasma cell-free DNA. A WGS-based DNA repair defect was associated with response (P = .02) and was reproduced in an independent cohort (P = .03).

CONCLUSIONS

Deescalation of radiotherapy to 30 Gy on the basis of intratreatment hypoxia imaging was feasible, safe, and associated with minimal toxicity. A DNA repair defect identified by WGS was predictive of response. Intratherapy personalization of chemoradiotherapy may facilitate marked deescalation of radiotherapy.

Hypoxia Inducible Factor-1alpha (HIF-1A) plays different roles in Gallbladder Cancer and Normal Gallbladder Tissues

Purpose: Hypoxia-inducible factor-1alpha (HIF-1A) is a transcription factor that plays an “angiogenic switch” role especially under hypoxia microenvironment in solid tumor. However, the functions and clinical significance of HIF-1A in gallbladder cancer (GBC) are still controversial, and it has not been studied in normal gallbladder tissues. In this study, we sought to clarify the role of sub-cellular localization of HIF-1A expression in GBC and normal gallbladder tissues.

Methods: The expressions of HIF-1A and CD34 in 127 GBC and 47 normal gallbladder tissues were evaluated by immunohistochemistry. Cox's proportional hazards model analysis and Kaplan-Meier method analysis were used to assess the correlations between these factors and clinicopathological features and prognosis.

Results: HIF-1A was expressed in both cytoplasm and nucleus of GBC and normal control tissues, and was significantly correlated with microvessel density (MVD). GBC tissues with positive nuclear HIF-1A expression had higher MVD compared to that with positive cytoplasmic HIF-1A expression; however, in normal gallbladder tissues, samples with positive cytoplasmic HIF-1A had higher MVD compared to that with positive nuclear HIF-1A expression. Moreover, GBC with nuclear HIF-1A expression tended to be more poorly differentiated and had larger tumor size compared to that with cytoplasm HIF-1A expression. Furthermore, GBC patients with nuclear HIF-1A positive were significantly correlated with worse overall survival (OS) compared with cytoplasmic HIF-1A positive. Multivariate Cox regression analysis identified lymph node metastasis and nuclear HIF-1A expression to be independent prognostic parameter in GBC.

Conclusions: Our findings provide evidence for the first time that HIF-1A is expressed in normal gallbladder tissues. Nuclear HIF-1A and cytoplasm HIF-1A plays different roles in GBC and normal gallbladder tissues.

PD-L1 in Combination with CD8+TIL and HIF-1α are Promising Prognosis Predictors of Head and Neck Squamous Cell Carcinoma

Objective

The aim of this study was to evaluate the prognosis effect of PD-L1 in combination with CD8⁺ tumor-infiltrating lymphocyte (TIL) or HIF-1α in head and neck squamous cell carcinoma (HNSCC).

Methods

A total of 63 patients who underwent surgical resection were included in this study. The level of PD-L1, CD8⁺ TIL, and HIF-1α was determined by immunohistochemical analysis. The survival of patients was evaluated by Kaplan–Meier analysis. The prognostic power of these parameters was evaluated by C-index.

Results

We observed that the survival of patients, who had a high level of PD-L1 in tumor cells, was significantly shorter than those who had a low level of PD-L1. However, the survival of patients who had a high level of PD-L1 in tumor microenvironment was significantly longer than patients with a low level of PD-L1 in tumor microenvironment. In addition, high level of CD8⁺ tumor-infiltrating lymphocyte or low level of HIF-1α level suggests a better prognosis. Moreover, we observed that PD-L1 in combination with CD8⁺ tumor-infiltrating lymphocyte and HIF-1α could significantly improve the prognostic effect of current TNM stage.

Conclusion

The results of this study suggest that the level of PD-L1, CD8⁺TIL, and HIF-1α are useful prognostic biomarkers for patients with HNSCC. Incorporating these biomarkers into current TNM stage of HNSCC improve the discriminatory capability of TNM stage.

The predictive power of CD3+ T cell infiltration of oral squamous cell tumors is limited to non-diabetic patients

Diabetes mellitus type II (DM) and immune cell infiltration determine patient outcome in many tumor entities. Here we studied a possible link between the metabolic and immune cell status of OSCC patients. Glucose transporter (GLUT) 1 mRNA expression was elevated in all tumor samples, whereas other glycolytic markers such as lactate dehydrogenase (LDH) A or monocarboxylate transporter (MCT) 1 were increased in tumor samples from patients with diabetes and these patients had a significantly worse prognosis compared to non-diabetic patients. Analyses of immune cell infiltration in tumors from diabetic and non-diabetic patients revealed an increased leukocyte (CD45⁺) infiltration compared to normal mucosa only in non-diabetic patients. In line, the amount of CD3⁺ T cells per mm² tumor tissue, was elevated in patients without diabetes and crucial for patient outcome in OSCC patients without diabetes, as compared to healthy mucosa using fluorescence immunohistochemistry in tissue microarrays of 229 patients. Our results demonstrate that diabetes is a prognostic factor for OSCC patients and associates with decreased leukocyte and CD3⁺ infiltration indicating that metabolic differences between diabetic and non-diabetic patients may alter tumor-infiltrating T cells and thereby determine patient outcome.

Head and neck squamous cell carcinoma

Most head and neck cancers are derived from the mucosal epithelium in the oral cavity, pharynx and larynx and are known collectively as head and neck squamous cell carcinoma (HNSCC). Oral cavity and larynx cancers are generally associated with tobacco consumption, alcohol abuse or both, whereas pharynx cancers are increasingly attributed to infection with human papillomavirus (HPV), primarily HPV-16. Thus, HNSCC can be separated into HPV-negative and HPV-positive HNSCC. Despite evidence of histological progression from cellular atypia through various degrees of dysplasia, ultimately leading to invasive HNSCC, most patients are diagnosed with late-stage HNSCC without a clinically evident antecedent pre-malignant lesion. Traditional staging of HNSCC using the tumour-node-metastasis system has been supplemented by the 2017 AJCC/UICC staging system, which incorporates additional information relevant to HPV-positive disease. Treatment is generally multimodal, consisting of surgery followed by chemoradiotherapy (CRT) for oral cavity cancers and primary CRT for pharynx and larynx cancers. The EGFR monoclonal antibody cetuximab is generally used in combination with radiation in HPV-negative HNSCC where comorbidities prevent the use of cytotoxic chemotherapy. The FDA approved the immune checkpoint inhibitors pembrolizumab and nivolumab for treatment of recurrent or metastatic HNSCC and pembrolizumab as primary treatment for unresectable disease. Elucidation of the molecular genetic landscape of HNSCC over the past decade has revealed new opportunities for therapeutic intervention. Ongoing efforts aim to integrate our understanding of HNSCC biology and immunobiology to identify predictive biomarkers that will enable delivery of the most effective, least-toxic therapies.

HIF-1a expression and differential effects on survival in patients with oral cavity, larynx, and oropharynx squamous cell carcinomas

BACKGROUND

Hypoxia is a negative prognostic factor in head and neck squamous cell carcinomas. Under hypoxia, the hypoxia-inducible factor (HIF)-1a transcription factor is overexpressed. We investigated whether there were site differences in HIF-1a expression and its effect on patient outcomes per subsite.

DESIGN/METHOD

A total of 941 patients with HNSCC in the squamous cell carcinoma of the oropharynx (OPSCC, n = 302), oral cavity (OSCC, n = 391), or larynx (LSCC, n = 248) were included. Expression of HIF-1a in tissue samples was investigated using immunohistochemistry. Overall survival (OS), disease-free survival (DFS), and locoregional control (LRC) were analyzed.

RESULTS

HIF-1a expression was higher in OSCC than in LSCC and OPSCC. High HIF-1a expression led to worse prognosis in OPSCC (OS P = .029, DFS P = .085) and LSCC (OS P = .041, DFS P = .011) and better in OSCC (OS P = .055, DFS P = .012). There was no association between HIF-1a and LRC.

CONCLUSIONS

High HIF-1a expression is related to poor outcome in OPSCC and LSCC and better outcome in OSCC.

AKT inhibition as a strategy for targeting hypoxic HPV-positive HNSCC

BACKGROUND AND PURPOSE

Hypoxia negatively affects treatment outcome in both Human papillomavirus (HPV)-positive and -negative head and neck squamous cell carcinomas (HNSCC). Despite HPV-positive patients having a relatively good prognosis, hypoxic HPV-positive tumours are associated with poor treatment outcome, and do not respond to hypoxia modification. Earlier, we showed that hypoxia induces the pro-survival AKT pathway. In this study, we aim to investigate whether AKT inhibition affects the response to radiotherapy under hypoxia, and determine whether this is a viable treatment strategy for HNSCC patients with hypoxic HPV-positive tumours.

MATERIALS AND METHODS

Nine HPV-negative and 4 HPV-positive HNSCC cell lines were characterized. AKT activation was assessed by western blot. Survival in response to hypoxic incubation, AKT inhibition and/or irradiation was assessed using CCK8 assays and colony forming assays.

RESULTS

AKT was activated under hypoxia in both HPV-negative and -positive cell lines, which could be abrogated by the AKT inhibitor MK2206. HPV-positive cell lines were highly sensitive to MK2206 at normoxia. In all HNSCC cell lines, AKT inhibition was significantly more effective in inhibiting cell growth during hypoxic conditions than under normoxia. Hypoxia significantly reduced radiosensitivity irrespective of HPV-status, yet specifically in HPV-positive cells this could be efficiently reversed by AKT inhibition.

CONCLUSIONS

These data suggest that HNSCC tumours are dependent on AKT to survive hypoxia, and that AKT inhibition is specifically effective in radioresistant hypoxic HPV-positive cells. Targeting AKT may thus be a potential way to overcome hypoxia induced radioresistance, particularly in HPV-positive HNSCC tumours.

'Good cancer gone bad': a narrative review of HPV oropharyngeal cancer and potential poor outcomes

PURPOSE

Oropharyngeal cancer (OPC) remains a significant health burden and about 15-30% of these have been attributed to the human papillomavirus (HPV). Human papillomavirus-related oropharyngeal cancer (HPV OPC) includes tumours which are detected to be p16INK4A positive or have the HPV DNA detected by in situ hybridisation or polymerase chain reaction. HPV OPC is generally believed to have a relatively good prognosis. More recently, there is a recognised pattern of atypical spread in a highly aggressive subset of HPV OPC. These are HPV OPCs which develop distant metastasis or recurrence. This review raises awareness of this subset of HPV OPC and factors associated with poor outcomes.

METHODS

A review of the literature available on HPV OPC was carried out. Studies were sourced from PubMed with searching of relevant headings and sub-headings and cross-referencing.

RESULTS

Factors associated with highly aggressive HPV OPC include nodal stage and nodal morphology, alcohol and tobacco use, age and biological characteristics. Treatment options in cases of disease recurrence include salvage resection radiotherapy and/or chemotherapy and management options vary depending on the nature of recurrence and initial treatment. Recent updates in HPV OPC staging have made staging and treatment of tumours more accurate.

CONCLUSION

While HPV OPC overall carries a relatively good prognosis, it is important for clinicians to be aware of potentially highly aggressive cases of HPV OPC and to be aware of factors that should prompt close monitoring.

Clinico-pathological peculiarities of human papilloma virus driven head and neck squamous cell carcinoma: A comprehensive update

AIMS

The current article provides a detailed account of the current understanding of molecular and clinico-pathological aspects of Human papilloma virus (HPV) driven head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

The literature review included most of the landmark trials and clinical studies related to the HPV driven HNSCC.

KEY FINDINGS

HPV positive HNSCC differ distinctly from HPV negative tobacco-related HNSCC, especially in oropharyngeal region. Therefore, the American joint committee on cancer`s latest manual for classification and staging of cancer suggests a separate staging system for HPV positive oropharyngeal cancers. Despite the younger patients being affected and the high propensity for cervical metastasis, the HPV positive oropharyngeal cancers respond much better to the treatment. The association with wild type TP53 and low EGFR expression confers the favorable prognosis in HPV driven HNSCC. Since the association is not universal, we suggest checking for p53 and EGFR expression status before considering de-intensification of therapy. In addition, the presence of matted lymph nodes and five or more nodes could mean relatively poorer prognosis, and are not suitable for de-intensification of therapy. The same is also true probably with higher T stage and co-existing tobacco use. The methods for the detection of p16, HPV DNA, HPV E6/E7 mRNA, anti-E6/E7 antibodies, in tissue, in serum and in saliva of patients, along with their clinical implications are also discussed.

SIGNIFICANCE

This article provides latest developments on the HPV driven HNSCC. 'Diagnosis of transcriptionally active HPV infection,' 'Modalities for surveillance,' 'Implication of de-escalation of therapy' are some of the critical issues that could serve the medical, the research as well as the patient communities.

Correlative analyses between tissue-based hypoxia biomarkers and hypoxia PET imaging in head and neck cancer patients during radiochemotherapy-results from a prospective trial

PURPOSE

Tumor hypoxia impairs the response of head-and-neck cancer (HNSCC) patients to radiotherapy and can be detected both by tissue biomarkers and PET imaging. However, the value of hypoxia biomarkers and imaging for predicting HNSCC patient outcomes are incompletely understood, and potential correlations between tissue and PET data remain to be elucidated. Here, we performed exploratory analyses of potential correlations between tissue-based hypoxia biomarkers and longitudinal hypoxia imaging in a prospective trial of HNSCC patients.

METHODS

Forty-nine patients undergoing chemoradiation for locally advanced HNSCCs were enrolled in this prospective trial. They underwent baseline biopsies and [¹⁸F]FDG PET imaging and [¹⁸F]FMISO PET at weeks 0, 2, and 5 during treatment. Immunohistochemical analyses for p16, Ki67, CD34, HIF1α, CAIX, Ku80, and CD44 were performed, and HPV status was assessed. Biomarker expression was correlated with biological imaging information and patient outcome data.

RESULTS

High HIF1α tumor levels significantly correlated with increased tumor hypoxia at week 2 as assessed by the difference in the [¹⁸F]FMISO tumor-to-background ratios, and high HIF1α and CAIX expressions were both associated with a deferred decrease in hypoxia between weeks 2 and 5. Loco-regional recurrence rates after radiotherapy were significantly higher in patients with high CAIX expression and also increased for high levels of the DNA repair factor Ku80. HPV status did not correlate with any of the tested hypoxia biomarkers, and HPV-positive patients showed higher loco-regional control rates and progression-free survival independent of their hypoxia dynamics.

CONCLUSION

In this exploratory trial, high expression of the tissue-based hypoxia biomarkers HIF1α and CAIX correlated with adverse hypoxia dynamics in HNSCCs during chemoradiation as assessed by PET imaging, and high CAIX levels were associated with increased loco-regional recurrence rates. Hence, hypoxia biomarkers warrant further investigations as potential predictors of hypoxia dynamics and hypoxia-associated radiation resistance.

mTOR Signalling in Head and Neck Cancer: Heads Up

The mammalian target of rapamycin (mTOR) signalling pathway is a central regulator of metabolism in all cells. It senses intracellular and extracellular signals and nutrient levels, and coordinates the metabolic requirements for cell growth, survival, and proliferation. Genetic alterations that deregulate mTOR signalling lead to metabolic reprogramming, resulting in the development of several cancers including those of the head and neck. Gain-of-function mutations in EGFR, PIK3CA, and HRAS, or loss-of-function in p53 and PTEN are often associated with mTOR hyperactivation, whereas mutations identified from The Cancer Genome Atlas (TCGA) dataset that potentially lead to aberrant mTOR signalling are found in the EIF4G1, PLD1, RAC1, and SZT2 genes. In this review, we discuss how these mutant genes could affect mTOR signalling and highlight their impact on metabolic processes, as well as suggest potential targets for therapeutic intervention, primarily in head and neck cancer.

Prognostic role of glycolysis for cancer outcome: evidence from 86 studies

OBJECTIVE

The abnormal expression of the key enzymes in glycolytic pathways, including glucose transporter-1, glucose transporter-3, hexokinase-II, lactate dehydrogenase 5, pyruvate kinase M2, glucose-6-phosphate dehydrogenase, transketolase-like protein 1 and pyruvate dehydrogenase kinase-1 was reported to be associated with poor prognosis of various cancers. However, the association remains controversial. The objective of this study was to investigate the prognostic significance of glycolysis-related proteins.

MATERIALS AND METHODS

We searched MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, using Pubmed and Ovid as search engines and Google Scholar from inception to April 2017. Eighty-six studies with 12,002 patients were included in the study.

RESULTS

Our pooled results identified that glycolysis-related proteins in cancers were associated with shorter overall survival of colorectal cancer (HR 2.33, 95% CI 1.38-3.93, P = 0.002), gastric cancer (HR 1.55, 95% CI 1.31-1.82, P < 0.001), cancer of gallbladder or bile duct (HR 2.16, 95% CI 1.70-2.75, P < 0.001), oral cancer (HR 2.07, 95% CI 1.32-3.25, P < 0.001), esophageal cancer (HR 1.66, 95% CI 1.25-2.21, P = 0.01), hepatocellular carcinoma (HR 2.04, 95% CI 1.64-2.54, P < 0.001), pancreatic cancer (HR 1.72, 95% CI 1.39-2.13, P < 0.001), breast cancer(HR 1.67, 95% CI 1.34-2.08, P < 0.001), and nasopharyngeal carcinoma (HR 3.59, 95% CI 1.75-7.36, P < 0.001). No association was found for lung cancer, ovarian cancer or melanoma. The key glycolytic transcriptional regulators (HIF-1α, p53) were analyzed in parallel to the glycolysis-related proteins, and the pooled results identified that high-level expression of HIF-1α was significantly associated with shorter overall survival (HR 0.57, 95% CI 0.42-0.79, P < 0.001) Furthermore, glycolysis-related proteins linked with poor differentiated tumors (OR 1.81, 95% CI 1.46-2.25, P < 0.001), positive lymph node metastasis (OR 2.73, 95% CI 2.16-3.46, P < 0.001), positive vascular invasion (OR 2.05, 95% CI 1.37-3.07, P < 0.001), large tumor size (OR 2.06, 95% CI 1.80-2.37, P < 0.001), advanced tumor stage (OR 1.58, 95% CI 1.19-2.09, P < 0.001), and deeper invasion (OR 2.37, 95% CI 1.93-2.91, P < 0.001).

CONCLUSION

Glycolytic transcriptional regulators and glycolysis-related proteins in cancers were significantly associated with poor prognosis, suggesting glycolytic status may be potentially valuable prognostic biomarkers for various cancers.

HPV, hypoxia and radiation response in head and neck cancer

Over the last decades, the incidence of human papilloma virus (HPV) positive head and neck squamous-cell carcinoma (HNSCC) has significantly increased. Infection with high-risk HPV types drives tumourigenesis through expression of the oncoproteins E6 and E7. Currently, the primary treatment of HNSCC consists of radiotherapy, often combined with platinum-based chemotherapeutics. One of the common features of HNSCC is the occurrence of tumour hypoxia, which impairs the efficacy of radiotherapy and is a negative prognostic factor. Therefore, it is important to detect and quantify the severity of hypoxia, as well as develop strategies to specifically target hypoxic tumours. HPV-positive tumours are remarkably radiosensitive compared to HPV-negative tumours and consequently the HPV-positive patients have a better prognosis. This provides an opportunity to elucidate mechanisms of radiation sensitivity, which may reveal targets for improved therapy for HPV-negative head and neck cancers. In this review, we will discuss the differences between HPV-positive and HPV-negative head and neck tumours and methods of hypoxia detection and targeting in these disease types. Particular emphasis will be placed on the mechanisms by which HPV infection impacts radiosensitivity.

Warburg effect, lactate dehydrogenase, and radio/chemo-therapy efficacy

The anaerobic metabolism of glucose by cancer cells, even under well-oxygenated conditions, has been documented by Otto Warburg as early as 1927. Micro-environmental hypoxia and intracellular pathways activating the hypoxia-related gene response, shift cancer cell metabolism to anaerobic pathways. In the current review, we focus on a major enzyme involved in anaerobic transformation of pyruvate to lactate, namely lactate dehydrogenase 5 (LDH5). The value of LDH5 as a marker of prognosis of cancer patients, as a predictor of response to radiotherapy (RT) and chemotherapy and, finally, as a major target for cancer treatment and radio-sensitization is reported and discussed. Clinical, translational and experimental data supporting the uniqueness of the LDHA gene and its product LDH5 isoenzyme are summarized and future directions for a metabolic treatment of cancer are highlighted.

Prognostic value of GLUT-1 expression in oral squamous cell carcinoma: A prisma-compliant meta-analysis

BACKGROUND

A variety of studies have evaluated the correlation between glucose transporter-1 (GLUT-1) expression and prognosis of oral squamous cell carcinoma (OSCC); however, the results were inconsistent and inconclusive. A meta-analysis was performed to assess the prognostic significance of GLUT-1 in OSCC.

METHODS

Electronic databases of PubMed, Embase, and Web of Science were searched for relevant studies. The last search was updated on July 2016. Odds ratio (OR) and 95% confidence interval (CI) were pooled to evaluate the relationship between GLUT-1 and clinical features and hazard ratio (HR) and 95% CI were combined to measure the effect of GLUT-1 on overall survival (OS). P value < 0.05 was considered as statistically significant.

RESULTS

A total of 13 studies with 1301 subjects were included for meta-analysis. The pooled data showed that high GLUT-1 expression was associated with advanced tumor stages (n = 7, OR = 2.99, 95% CI: 2.01-4.46, P < 0.001), higher tumor grade (n = 5, OR = 3.34, 95%CI: 1.12-9.94, P = 0.031), tumor size (n = 5, OR = 3.36, 95%CI: 2.04-5.51, P < 0.001), lymph node metastasis (n = 5, OR = 3.15, 95%CI: 1.89-5.25, P < 0.001), tobacco use (n = 3, OR = 2.18, 95%CI: 1.18-4.01, P = 0.013), and distant metastasis (n = 2, OR = 3.06, 95%CI: 1.19-7.9, P = 0.02). Furthermore, increased GLUT-1 expression was also correlated with shorter OS (n = 8, HR = 1.88, 95%CI: 1.51-2.33, P < 0.001). No significant publication bias was detected in this meta-analysis.

CONCLUSION

GLUT-1 overexpression was in connection with aggressive clinical features and worse OS in OSCC. However, further studies are still needed to verify whether GLUT-1 could serve as a prognostic biomarker for OSCC.