Expression of Glut-1 in primary and recurrent head and neck squamous cell carcinomas, and compared with 2-[18F]fluoro-2-deoxy-D-glucose accumulation in positron emission tomography

Strategies to Overcome Intrinsic and Acquired Resistance to Chemoradiotherapy in Head and Neck Cancer

Definitive chemoradiotherapy (CRT) is a cornerstone of treatment for locoregionally advanced head and neck cancer (HNC). Research is ongoing on how to improve the tumor response to treatment and limit normal tissue toxicity. A major limitation in that regard is the growing occurrence of intrinsic or acquired treatment resistance in advanced cases. In this review, we will discuss how overexpression of efflux pumps, perturbation of apoptosis-related factors, increased expression of antioxidants, glucose metabolism, metallotheionein expression, increased DNA repair, cancer stem cells, epithelial-mesenchymal transition, non-coding RNA and the tumour microenvironment contribute towards resistance of HNC to chemotherapy and/or radiotherapy. These mechanisms have been investigated for years and been exploited for therapeutic gain in resistant patients, paving the way to the development of new promising drugs. Since in vitro studies on resistance requires a suitable model, we will also summarize published techniques and treatment schedules that have been shown to generate acquired resistance to chemo- and/or radiotherapy that most closely mimics the clinical scenario.

18F-FDG PET cannot predict expression of clinically relevant histopathological biomarkers in head and neck squamous cell carcinoma: a meta-analysis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a common cancer. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) is a widely used imaging modality in HNSCC.

PURPOSE

To provide evident data about associations between 18F-FDG PET and histopathology in HNSCC.

MATERIAL AND METHODS

The MEDLINE database was screened for associations between maximum standard uptake values (SUV_max) derived from 18F-FDG PET and histopathological features in HNSCC up to May 2020. Only papers containing correlation coefficients between SUV_max and histopathology were acquired. Overall, 23 publications were collected.

RESULTS

The following correlations were calculated: KI 67: 12 studies (345 patients), pooled correlation coefficient (PCC): 0.23 (95% confidence interval [CI] 0.06-0.40); hypoxia-inducible factor-1α: eight studies (240 patients), PCC: 0.24 (95% CI 0.06-0.42); microvessel density: three studies (64 patients), PCC: 0.33 (95% CI 0.02-0.65); vascular endothelial growth factor: two studies (59 cases), PCC: 0.27 (95% CI 0.02-0.51); tumor suppressor protein p53: four studies (159 patients), PCC: 0.05 (95% CI -0.41 to 0.51); epidermal growth factor receptor: two studies (124 patients), PCC: 0.21 (95% CI 0.05-0.37); tumor cell count: three studies (67 patients), PCC: 0.18 (95% CI -0.06 to 0.42); tumor cell apoptosis: two studies (40 patients), PCC: 0.07 (95% CI = -0.85 to 0.99); B-cell lymphoma-2 protein: two studies (118 patients); PCC: 0.04 (95% CI -0.65 to 0.74); glucose-transporter 1: 10 studies (317 patients), PCC: 0.20 (95% CI 0.10-0.30).

CONCLUSION

SUV_max derived from 18F-FDG PET cannot reflect relevant histopathological features in HNSCC.

The Role of Glucose Transporters in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a prevalent malignancy associated with a poor prognosis. The Warburg effect can be observed in OSCCs, with tumours requiring a robust glucose supply. Glucose transporters (GLUTs) and sodium-glucose co-transporters (SGLTs) are overexpressed in multiple malignancies, and are correlated with treatment resistance, clinical factors, and poor overall survival (OS). We conducted a systematic review to evaluate the differences in GLUT/SGLT expression between OSCC and normal oral keratinocytes (NOK), as well as their role in the pathophysiology and prognosis of OSCC. A total of 85 studies were included after screening 781 papers. GLUT-1 is regularly expressed in OSCC and was found to be overexpressed in comparison to NOK, with high expression correlated to tumour stage, treatment resistance, and poor prognosis. No clear association was found between GLUT-1 and tumour grade, metastasis, and fluorodeoxyglucose (FDG) uptake. GLUT-3 was less thoroughly studied but could be detected in most samples and is generally overexpressed compared to NOK. GLUT-3 negatively correlated with overall survival (OS), but there was insufficient data for correlations with other clinical factors. Expression of GLUT-2/GLUT-4/GLUT-8/GLUT-13/SGLT-1/SGLT-2 was only evaluated in a small number of studies with no significant differences detected. GLUTs 7 and 14 have never been evaluated in OSCC. In conclusion, the data demonstrates that GLUT-1 and GLUT-3 have a role in the pathophysiology of OSCC and represent valuable biomarkers to aid OSCC diagnosis and prognostication. Other GLUTs are comparatively understudied and should be further analysed because they may hold promise to improve patient care.

FDG PET correlates weakly with HIF-1 expression in solid tumors: a meta-analysis

BACKGROUND

Hypoxia-inducible factor (HIF)-1α plays a key role in hypoxic adaptation of tumor cells. Overexpression of HIF-1α is associated with tumor aggressiveness and worse prognosis in several malignancies. Presumably, expression of HIF-1a may be reflected by positron emission tomography with 2-deoxy-2 [fluorine-18] fluoro-D-glucose (18F-FDG PET). There are inconsistent data about relationships between FDG PET and HIF-1α.

PURPOSE

To provide evident data about associations between maximum standardized uptake value (SUV_max) and HIF-1α expression in solid tumors.

MATERIAL AND METHODS

MEDLINE, SCOPUS, and EMBASE databases were screened for relationships between SUV and HIF-1α up to August 2019. Overall, 21 studies with 1154 patients were identified. The following data were extracted from the literature: authors; year of publication; number of patients; and correlation coefficients.

RESULTS

Correlation coefficients between SUV_max and HIF-1α were in the range of -0.51-0.71. The pooled correlation coefficient was 0.27 (95% confidence interval [CI] = 0.14-0.41). Furthermore, correlation coefficients for some tumor entities were calculated. For this sub-analysis, data for primary tumors with >2 reports were included. The calculated correlation coefficients in the analyzed subgroups were as follows: head and neck squamous cell carcinoma: ρ = 0.25 (95% CI = 0.07-0.42); non-small lung cell cancer: ρ = 0.27 (95% CI = -0.14-0.67); uterine cervical cancer: ρ = -0.09 (95% CI = -0.89-0.71); thymic tumors: ρ = 0.39 (95% CI = 0.04-0.58).

CONCLUSION

SUV_max of FDG PET correlated weakly with expression of HIF-1α both in overall sample and tumor subgroups. Therefore, FDG PET cannot be used for prediction of hypoxia in clinical practice.

A Novel Prognostic Index Based on the Analysis of Glycolysis-Related Genes in Head and Neck Squamous Cell Carcinomas

Aims

The preferential dependence on glycolysis as a pathway of energy metabolism is a hallmark of cancer cells. However, the prognostic significance of glycolysis-related genes in head and neck squamous cell carcinoma (HNSCC) remains obscure. The purpose of this study was to identify glycolysis-related genes of prognostic value in HNSCC.

Results

Transcriptional and clinical data of 544 HNSCC samples were obtained from The Cancer Genome Atlas (TCGA) dataset. By gene set enrichment analysis (GSEA) and by employing a univariate and subsequently a stepwise multivariate Cox proportional regression model, eight glycolysis-related genes of prognostic significance in HNSCC (KIF2A, JMJD8, HMMR, STC2, HK1, EXT2, GPR8, and STC1) were identified. The patients were clustered into two groups (high and low risk) based on the expression of these genes. High-risk patients had significantly a shorter overall survival than low-risk patients. Furthermore, a new prognostic indicator based on selected glycolysis-related genes was developed by multivariate Cox analysis that proved to be a better predictor of patient outcome compared to other clinical factors.

Conclusion

Our findings provide new insights into the role of glycolysis in HNSCC. The identified genes predict the patient prognosis and might substantially contribute to the development of individualized treatments.

Histometabolic Tumor Imaging of Hypoxia in Oral Cancer: Clinicopathological Correlation for Prediction of an Aggressive Phenotype

Introduction

Fluorodeoxyglucose-positron emission tomography (FDG-PET) is a widely used imaging tool for oral squamous cell carcinoma (OSCC). Preliminary studies indicate that quantification of tumor metabolic uptake may correlate with tumor hypoxia and aggressive phenotypes.

Methods

Retrospective review of a consecutive cohort of OSCC (n = 98) with available pretherapeutic FDG-PET/CT, treated at the University Hospital Zurich. Clinico-pathologico-radiological correlation between maximum standard uptake value (SUV_max) of the primary tumor, immunohistochemical staining for hypoxia-related proteins glucose transporter 1 (GLUT1) and hypoxia-inducible factor 1-alpha (HIF1a), depth of invasion (DOI), lymph node metastasis, and outcome was examined.

Results

Positive staining for GLUT1 and HIF1a on immunohistopathological analysis correlated with increased SUV_max on pretherapeutic imaging and with increased DOI (Kruskal–Wallis, P = 0.037, and P = 0.008, respectively). SUV_max and DOI showed a strong positive correlation (Spearman Rho, correlation coefficient = 0.451, P = 0.0003). An increase in SUV_max predicted nodal metastasis (Kruskal–Wallis, P = 0.017) and poor local control (log rank, P = 0.047).

Conclusion

In OSCC, FDG-PET-derived metabolic tumor parameter SUV_max serves as a surrogate marker for hypoxia and can be used to predict tumor aggressiveness, with more invasive phenotypes and poorer local control.

Associations Between [18F]FDG-PET and Complex Histopathological Parameters Including Tumor Cell Count and Expression of KI 67, EGFR, VEGF, HIF-1α, and p53 in Head and Neck Squamous Cell Carcinoma

PURPOSE

Head and neck squamous cell carcinoma (HNSCC) is one of common cancers worldwide. Positron emission tomography (PET) with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) is increasingly used for diagnosing and staging, as well as for monitoring of treatment of HNSCC. PET parameters like maximum and mean standard uptake values (SUV_max, SUV_mean) can predict the behavior of HNSCC. The purpose of this study was to analyze possible associations between these PET parameters and clinically relevant histopathological features in patients with HNSCC.

PROCEDURES

Overall, 22 patients, mean age, 55.2 ± 11.0 years, with different HNSCC were acquired. Low grade (G1/2) tumors were diagnosed in 10 cases (45 %) and high grade (G3) tumor in 12 (55 %) patients. In all cases, whole body PET was performed. For this study, the following specimen stainings were performed: MIB-1 staining (KI 67 expression), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), tumor suppressor protein p53, hypoxia-inducible factor (HIF)-1α, and human papilloma virus (p16 expression). All stained specimens were digitalized and analyzed by using the ImageJ software 1.48v. Spearman's correlation coefficient (ρ) was used to analyze associations between investigated parameters. P values <0.05 were taken to indicate statistical significance.

RESULTS

P16-negative tumors showed statistically significant higher SUV_max (ρ = 0.006) and SUV_mean values (ρ = 0.002) in comparison to p16-positive carcinomas. No significant differences were identified in the analyzed parameters between poorly and moderately/well-differentiated tumors. In overall sample, there were no statistically significant correlations between the [¹⁸F]FDG-PET and histopathological parameters. Also, in G1/2 tumors, no significant correlations were identified. In G3 carcinomas, cell count correlated statistical significant with SUV_max (p = 0.580, P = 0.048) and SUV_mean (ρ = 0.587, P = 0.045).

CONCLUSION

Associations between [¹⁸F]FDG-PET parameters and different histopathological features in HNSCC depend significantly on tumor grading. In G1/2 carcinomas, there were no significant correlations between [¹⁸F]FDG-PET parameters and histopathology. In G3 lesions, SUV_max and SUV_mean reflect tumor cellularity.

Associations between GLUT expression and SUV values derived from FDG-PET in different tumors-A systematic review and meta analysis

PURPOSE

Fluorodeoxyglucose-Positron-emission tomography (FDG-PET), quantified by standardized uptake values (SUV), is one of the most used functional imaging modality in clinical routine. It is widely acknowledged to be strongly associated with Glucose-transporter family (GLUT)-expression in tumors, which mediates the glucose uptake into cells. The present systematic review sought to elucidate the association between GLUT 1 and 3 expression with SUV values in various tumors.

METHODS

MEDLINE library was screened for associations between FDG-PET parameters and GLUT correlation cancer up to October 2018.

RESULTS

There were 53 studies comprising 2291 patients involving GLUT 1 expression and 11 studies comprising 405 patients of GLUT 3 expression. The pooled correlation coefficient for GLUT 1 was r = 0.46 (95% CI 0.40-0.52), for GLUT 3 was r = 0.35 (95%CI 0.24-0.46). Thereafter, subgroup analyses were performed. The highest correlation coefficient for GLUT 1 was found in pancreatic cancer r = 0.60 (95%CI 0.46-0.75), the lowest was identified in colorectal cancer with r = 0.21 (95% CI -0.57-0.09).

CONCLUSION

An overall only moderate association was found between GLUT 1 expression and SUV values derived from FDG-PET. The correlation coefficient with GLUT 3 was weaker. Presumably, the underlying mechanisms of glucose hypermetabolism in tumors are more complex and not solely depended on the GLUT expression.

Roles of GLUT-1 and HK-II expression in the biological behavior of head and neck cancer

The Warburg effect plays an important role in the proliferation and invasion of malignant tumors. Glucose transporter 1 and hexokinase II are two key energy transporters involved in mediating the Warburg effect. This review will analyze the mechanisms of these two markers in their effects on the biological behavior of head and neck cancer.

18F-FDG-PET Can Predict Microvessel Density in Head and Neck Squamous Cell Carcinoma

Aim: Positron emission tomography (PET) with ¹⁸F-fluordeoxyglucose (¹⁸F-FDG) plays an essential role in the staging and tumor monitoring of head and neck squamous cell carcinoma (HNSCC). Microvessel density (MVD) is one of the clinically important histopathological features in HNSCC. The purpose of this study was to analyze possible associations between ¹⁸F-FDG-PET findings and MVD parameters in HNSCC. Materials and Methods: Overall, 22 patients with a mean age of 55.2 ± 11.0 and with different HNSCC were acquired. In all cases, whole-body ¹⁸F-FDG-PET was performed. For each tumor, the maximum and mean standardized uptake values (SUV_max; SUV_mean) were determined. The MVD, including stained vessel area and total number of vessels, was estimated on CD105 stained specimens. All specimens were digitalized and analyzed by using ImageJ software 1.48v. Spearman's correlation coefficient (r) was used to analyze associations between investigated parameters. p-values of <0.05 were taken to indicate statistical significance. Results: SUV_max correlated with vessel area (r = 0.532, p = 0.011) and vessel count (r = 0.434, p = 0.043). Receiver operating characteristic analysis identified a threshold SUV_max of 15 to predict tumors with high MVD with a sensitivity of 72.7% and specificity of 81.8%, with an area under the curve of 82.6%. Conclusion: ⁸F-FDG-PET parameters correlate statistically significantly with MVD in HNSCC. SUV_max may be used for discrimination of tumors with high tumor-related MVD.

Combined Metabolo-Volumetric Parameters of 18F-FDG-PET and MRI Can Predict Tumor Cellularity, Ki67 Level and Expression of HIF 1alpha in Head and Neck Squamous Cell Carcinoma: A Pilot Study

BACKGROUND: Our purpose was to evaluate associations of combined ¹⁸F-FDG-PET and MRI parameters with histopathological features in head and neck squamous cell carcinoma (HNSCC). METHODS: Overall, 22 patients with HNSCC were acquired (10 with G1/2 tumors and 12 with G3 tumors).¹⁸F-FDG-PET/CT and MRI was performed and maximum standardized uptake value (SUV_max), total lesion glycolysis (TLG) and metabolic tumor volume (MTV) were estimated. Neck MRI was obtained on a 3 T scanner. Diffusion weighted imaging was performed with estimation of apparent diffusion coefficient (ADC). Perfusion parameters K_trans,V_e, and K_ep were derived from dynamic contrast-enhanced (DCE) imaging. Different combined PET/MRI parameters were calculated as ratios: PET parameters divided by ADC or DCE MRI parameters. The following histopathological features were estimated: Ki 67, EGFR, VEGF, p53, hypoxia-inducible factor (HIF)-1α, and cell count. Spearman's correlation coefficient (p) was used for correlation analysis. P < .05 was taken to indicate statistical significance. RESULTS: In overall sample, cellularity correlated with SUV_max/ADC_min (P = .558, P = .007), TLG/ADC_min (P = .546, P = .009), and MTV/ADC_min (P = .468, P = .028). MTV/K_ep correlated with expression of HIF-1α (P = .450, P = 0,047). In G1/2 tumors, SUV_max/ADC_min correlated with HIF-1α (P = −.648, P = .043); MTV/K_ep (P = −.669, P = .034) and TLG/K_ep (P = −.644, P = .044) with Ki67. In G3 tumors, cellularity correlated with SUV_max/ADC_min (P = .832, P = .001), SUV_max/ADC_mean (P = .741, P = .006), and TLG/ADC_min (P = .678, P = .015). MTV/ADC_min and TLG/ADC_min tended to correlate with HIF-1α. CONCLUSION: Combined parameters of ¹⁸F-FDG-PET and MRI can reflect Ki 67, tumor cellularity and expression of HIF-1α in HNSCC. Associations between parameters of ¹⁸F-FDG-PET and MRI and histopathology depend on tumor grading.

Correlation between the malignancy and prognosis of oral squamous cell carcinoma in the maximum standardized uptake value

Positron emission tomography/computed tomography (PET/CT) examinations are indispensable in determining the stage, evaluating the treatment response, and diagnosing recurrence and metastasis during oral cancer treatment. In this study, we examined the correlation between the maximum standardized uptake value (SUVmax) for ¹⁸F-FDG PET/CT and the progressive factors, biological characteristics, and prognosis of oral cancer. We included 52 cases of oral squamous cell carcinoma with surgery as the initial treatment. Inclusion criteria included tumor diameter of ≥ 1 cm excluding superficial cancer. We performed 18F-FDG PET/CT examinations before surgery and determined the correlation between SUVmax and clinicopathological factors, such as histological grade, Ki-67 expression, as well as progress factors. SUVmax was significantly correlated with clinical T stage, vascular invasion, lymphatic invasion, Ki-67 expression, and postoperative event (recurrence or metastasis) in Student's t test. Using a cut-off SUVmax of 8.0, clinical T stage, lymph node metastasis, vascular invasion, infiltrative pattern, and Ki-67 expression significantly correlated in chi-squared test. Although observed and expected 3-year overall survival rates were not significantly different, observed and expected 3-year disease-free survival rates were significantly different. Analyzing each clinicopathological factor using various data obtained from ¹⁸F-FDG PET/CT scans may be useful to determine prognosis during oral cancer treatment.

Regulation of glycolysis in head and neck squamous cell carcinoma

Glycolysis is highly upregulated in head and neck squamous cell carcinoma (HNSCC). HNSCC glycolysis is an important contributor to disease progression and decreases sensitivity to radiation or chemotherapy. Despite therapeutic advances, the survival rates for HNSCC patients remain low. Understanding glycolysis regulation in HNSCC will facilitate the development of effective therapeutic strategies for this disease. In this review, we will evaluate the regulation of altered HNSCC glycolysis and possible therapeutic approaches by targeting glycolytic pathways.

Cutaneous and Subcutaneous Metastases From Atypical Laryngeal Carcinoids: Case Report and Review of the Literature

The incidence of cutaneous and subcutaneous metastases from atypical laryngeal carcinoids is approximately 20%. However, the pathogenesis and natural history of, and prognostic factors for, the condition remain poorly understood. We reported a 54-year-old female presented with cutaneous and subcutaneous metastases from atypical laryngeal carcinoid. Laryngoscopy revealed a 0.5 × 1.5-cm reddish mass on the laryngeal surface of the epiglottis. Under general anesthesia, a biopsy sample was obtained via suspension laryngoscopy. Routine pathology revealed atypical laryngeal carcinoid. Immunohistochemical staining of the sections of primary tumor was positive for cytokeratin, chromogranin A, synaptophysin, hypoxia-inducible factor-1α, P53, and CD56. GLUT-1, p-Akt, and PI3K were negative. The Ki-67 index was 15%. Supraglottic laryngectomy and selective right-neck dissection were performed. After 6 months, the patient complained of pain in the right wall of the chest; multiple cutaneous and subcutaneous nodules were evident at that site and in the abdomen. An abdominal nodule was biopsied and pathology revealed that the atypical metastatic carcinoid had metastasized to both cutaneous and subcutaneous areas of the abdomen. Chemotherapy was then prescribed. Currently, the intrathecal drug delivery system remains in place. No local recurrence has been detected. Furthermore, we systematically reviewed clinical manifestations of the disease, pathogenesis, prognostic factors, and treatment. The metastasis rate (cutaneous and subcutaneous) was approximately 12.2%. Thirty patients (62.5%) with cutaneous and subcutaneous metastases exhibited contemporaneous lymph node invasion. The 3-, 5-, and 10-year survival rates were 44.0%, 22.0%, and 13.0%, respectively. The prognosis of patients with atypical laryngeal carcinoids was poor. Relevant prognostic factors included the level of p53, human papilloma virus status, certain hypoxic markers, and distant metastasis. No optimal treatment for such metastases has yet been defined.

The association of (18)F-FDG PET and glucose metabolism biomarkers GLUT1 and HK2 in p16 positive and negative head and neck squamous cell carcinomas

OBJECTIVES

To investigate the relationship between FDG-PET maximum standard uptake value (SUVmax), p16, EGFR, GLUT1 and HK2 expression in head and neck squamous cell carcinomas (HNSCC).

MATERIALS AND METHODS

Immunohistochemical staining of p16, EGFR, GLUT1 and HK2 was performed on primary tumor tissue from 97 locally advanced HNSCC patients treated with definitive chemoradiation. SUVmax along with p16, EGFR, GLUT1 and HK2 expression were analyzed for associations including local control, locoregional control and disease free survival.

RESULTS

Pretreatment SUVmax in primary tumors did not differ when stratified by p16, EGFR or GLUT1 expression but SUVmax was significantly higher in HK2 expressing tumors (p=0.021) and in tumors with higher T-stage (p=0.022). GLUT1 expression was significantly higher in p16 negative (p<0.001) and EGFR positive tumors (p<0.01). HK2 expressing tumors were associated with EGFR positive tumors (p=0.022) but not with p16 or GLUT1 expression. EGFR positive, p16 negative and high GLUT1 expressing tumors were associated with worse local control and disease free survival on univariate analyses. After adjusting for patient and treatment characteristics p16 status was the only factor that predicted for outcome on multivariate analysis.

CONCLUSIONS

High GLUT1 expression was associated with EGFR positive and p16 negative HNSCC tumors. GLUT1 maybe an important biomarker in HNSCC but its expression appears dependent on p16 status.

Distribution of Hypoxia-Inducible Factor-1α and Glucose Transporter-1 in Human Tongue Cancers

PURPOSE

Oral squamous cell carcinomas have the potential for rapid and unlimited growth. Therefore, hypoxic tissue areas are common in these malignant tumors and contribute to cancer progression, therapy resistance, and poor outcomes. The aim of the present study was to analyze the gene product distribution of hypoxia-inducible factor-1α (HIF-1α) and glucose transporter-1 (GLUT-1) in cases of tongue squamous cell carcinoma (TSCC) and to identify a preliminary correlation between these proteins and clinical staging and Brynes's histologic grading system (HGS).

MATERIALS AND METHODS

The sample included 57 cases of TSCC. Histologic sections of 3 μm were submitted to the immunoperoxidase method and semiquantitative analysis. The association between HIF-1α and GLUT-1 expression in TSCC and the clinical stage and the HGS of Bryne (1998) was evaluated using the χ(2) test, with the significance level set at 0.05 (α = 0.05).

RESULTS

HIF-1α was mainly expressed in the nucleus/cytoplasm of neoplastic cells, most specimens exhibited diffuse staining in neoplastic cells (84.2%), and focal staining was only observed in perinecrotic areas (15.8%). GLUT-1 was expressed in the cytoplasm and membrane of malignant cells, and diffuse staining was observed in all cases. The intensity of HIF-1α expression correlated significantly with clinical stage (P = .011) and HGS (P = .002). A significant association was observed between the distribution of HIF-1α expression and metastasis (P = .040). Immunoexpression of GLUT-1 correlated significantly with clinical stage (P = .002) and HGS (P = .000). GLUT-1 expression in the peripheral island was predominant in most low-grade tumors (78.6%); in the high-grade cases, the expression prevailed in the location center/periphery (55.8%). Comparison of the location of the tumor island in the different histologic grades showed a statistically significant difference (P = .025).

CONCLUSION

The expression of HIF and GLUT proteins within TSCC appears to be associated with disease stage, grade, and the presence of metastases. Additional studies are needed to evaluate the diagnostic and prognostic uses of these proteins in the treatment of TSCC.

Hypoxia, blood flow and metabolism in squamous-cell carcinoma of the head and neck: correlations between multiple immunohistochemical parameters and PET

Background

The relationship between the uptake of [¹⁸F]fluoroerythronitroimidazole ([¹⁸F]FETNIM), blood flow ([¹⁵O]H₂O) and 2-[¹⁸F]fluoro-2-deoxyglucose ([¹⁸F]FDG) and immunohistochemically determined biomarkers was evaluated in squamous-cell carcinomas of the head and neck (HNSCC).

Methods

[¹⁸F]FETNIM and [¹⁸F]FDG PET were performed on separate days on 15 untreated patients with HNSCC. Hypoxia imaging with [¹⁸F]FETNIM was coupled with measurement of tumor blood flow using [¹⁵O]H₂O. Uptake of [¹⁸F]FETNIM was measured as tumor-to-plasma ratio (T/P) and fractional hypoxic volume (FHV), and that of [¹⁸F]FDG as standardized uptake value (SUV) and the metabolically active tumor volume (TV). Tumor biopsies were cut and stained for GLUT-1, Ki-67, p53, CD68, HIF-1α, VEGF_sc-152, CD31 and apoptosis. The expression of biomarkers was correlated to PET findings and patient outcome.

Results

None of the PET parameters depicting hypoxia and metabolism correlated with the expression of the biomarkers on a continuous scale. When PET parameters were divided into two groups according to median values, a significant association was detected between [¹⁸F]FDG SUV and p53 expression (p =0.029) using median SUV as the cut-off. There was a significant association between tumor volume and the amount of apoptotic cells (p =0.029). The intensity of VEGF stained cells was associated with [¹⁸F]FDG SUV (p =0.036). Patient outcome was associated with tumor macrophage content (p =0.050), but not with the other biomarkers. HIF-1α correlated with GLUT-1 (r_s =0.553, p =0.040) and Ki-67 with HIF-1α (r_s =506, p =0.065). p53 correlated inversely with GLUT-1 (r_s = −618, p =0.019) and apoptosis with Ki-67 (r_s = −638, p =0.014).

Conclusions

A high uptake of [¹⁸F]FDG expressed as SUV is linked to an aggressive HNSCC phenotype: the rate of apoptosis is low and the expressions of p53 and VEGF are high. None of the studied biomarkers correlated with perfusion and hypoxia as evaluated with [¹⁵O]H₂O-PET and [¹⁸F]FETNIM-PET. Increased tumor metabolism evaluated with PET may thus signify an aggressive phenotype, which should be taken into account in the management of HNSCC.

GLUT-1(+)/TKTL1(+) coexpression predicts poor outcome in oral squamous cell carcinoma

OBJECTIVE

Tumor hypoxia is a crucial negative prognostic factor associated with outcome of oral squamous cell carcinoma (OSCC).

STUDY DESIGN

Expression of glucose transporter 1 (GLUT-1) (solute carrier family 2 [facilitated glucose transporter], member 1 [SLC2A1]) was analyzed in OSCC specimen (n = 161) and cancer cell lines by immunohistochemistry and Western blotting. GLUT-1 expression on protein level was correlated with transketolase-like 1 (TKTL1) expression, clinical characteristics, and effect on survival. Subgroup analysis was performed for GLUT-1/TKTL1 coexpression.

RESULTS

GLUT-1 expression was significantly correlated with TKTL1 expression (P < .0001) and recurrence of the tumor (P = .001). Multivariate analysis did not find GLUT-1 expression to be an independent prognostic factor (P = .2478). GLUT-1(+)/TKTL1(+) subgroup showed the worst effect on survival compared with the GLUT-1(-)/TKTL1(-) subgroup (P = .0002).

CONCLUSIONS

This study provides evidence that tumors linked with combined enhanced glucose uptake (GLUT-1(+)) and hypoxia-related glucose metabolism (TKTL1(+)) characteristics (GLUT-1(+)/TKTL1(+) coexpression) are associated with shorter survival in OSCC.

Inhibition of Glucose Transporter 1 (GLUT1) Chemosensitized Head and Neck Cancer Cells to Cisplatin

Glucose transporter 1 (GLUT1) facilitates the cellular uptake of glucose and is overexpressed in most cancers. The altered expression of GLUT1 may influence the sensitivity of tumor cells to chemotherapy. This study investigated whether the knockdown of GLUT1 expression to sensitize head and neck cancer cells to the chemotherapy drug cisplatin in vitro. Anti-GLUT1 antibody was used to block activity of GLUT1 protein, and GLUT1-shRNA was used to knock down its mRNA expression in Cal27 cells. Immunocytochemistry, Western blot, and qRT-PCR were used to detect expression of GLUT1 mRNA and protein, respectively. Lentivirus was used to carrying GLUT1-shRNA to knockdown GLUT1 expression in Cal27 cells for MTT and flow cytometry analyses of cell viability and apoptosis, respectively. Glucose uptake assay was used to assess the changes in glucose levels in Cal27 cells. It showed that GLUT1 mRNA and protein were expressed in Cal27 cells, and GLUT1 protein was localized on the cell membrane. Both anti-GLUT1 antibody and GLUT1-shRNA sensitized Cal27 cells to cisplatin treatment under both normoxia and hypoxia conditions. Anti-GLUT1 antibody and GLUT1-shRNA inhibited tumor cell growth in vitro and induced them to undergo apoptosis. GLUT1-shRNA also suppressed tumor cell uptake of glucose into the cells. Our findings suggest that inhibition of GLUT1 activity and expression can sensitize Cal27 cells to cisplatin treatment in both normoxic and hypoxic conditions. These data could be further verified in animal xenografts before potential application as a clinical adjuvant or neoadjuvant therapy of head and neck cancer with cisplatin.

Diagnostic usefulness of ¹⁸F-FAMT PET and L-type amino acid transporter 1 (LAT1) expression in oral squamous cell carcinoma

PURPOSE

L-[3-(18)F]-α-Methyltyrosine ((18)F-FAMT) was developed as an amino acid tracer for PET imaging to provide better specificity than 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) PET for cancer diagnosis. We investigated the diagnostic usefulness of (18)F-FAMT in oral squamous cell carcinoma (OSCC). The correlation between tumour uptake of (18)F-FAMT and L-type amino acid transporter 1 (LAT1) expression was determined.

METHODS

The study group comprised 68 OSCC patients who underwent both (18)F-FAMT and (18)F-FDG PET. Resected tumour sections were stained by immunohistochemistry for LAT1, CD98 and Ki-67, and microvessel density was determined in terms of CD34 and p53 expression.

RESULTS

The sensitivity of primary tumour detection by (18)F-FAMT and (18)F-FDG PET was 98 % and 100 %, respectively. The sensitivity, specificity and accuracy of (18)F-FAMT PET for detecting malignant lymph nodes were 68 %, 99 % and 97 %, respectively, and equivalent values for (18)F-FDG PET were 84 %, 94 % and 94 %, respectively. The specificity and accuracy of (18)F-FAMT were significantly higher than those of (18)F-FDG. The uptake of (18)F-FAMT was significantly correlated with LAT1 expression, cell proliferation and advanced stage. The expression of LAT1 in OSCC cells was closely correlated with CD98 levels, cell proliferation and angiogenesis.

CONCLUSION

(18)F-FAMT PET showed higher specificity for detecting malignant lesions than (18)F-FDG PET. The uptake of (18)F-FAMT by OSCC cells can be determined by the presence of LAT1 expression and tumour cell proliferation.

Optical molecular imaging of multiple biomarkers of epithelial neoplasia: epidermal growth factor receptor expression and metabolic activity in oral mucosa

Biomarkers of cancer can indicate the presence of disease and serve as therapeutic targets. Our goal is to develop an optical imaging approach using molecularly targeted contrast agents to assess several centimeters of mucosal surface for mapping expression of multiple biomarkers simultaneously with high spatial resolution. The ability to image biomarker expression level and heterogeneity in vivo would be extremely useful for clinical cancer research, patient selection of personalized medicine, and monitoring therapy. In this proof-of-concept ex vivo study, we examined correlation of neoplasia with two clinically relevant biomarkers: epidermal growth factor receptor (EGFR) and metabolic activity. Two hundred eighty-six unique locations in nine samples of freshly resected oral mucosa were imaged after topically applying optical imaging agents EGF-Alexa 647 (to target EGFR) and 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (to target metabolic activity). Quantitative features were calculated from resulting fluorescence images and compared with tissue histopathology maps. The EGF-Alexa 647 signal correlated well with EGFR expression as indicated by immunohistochemistry. A classification algorithm for presence of neoplasia based on the signal from both contrast agents resulted in an area under the curve of 0.83. Regions with a posterior probability from 0.80 to 1.00 contained more than 50% neoplasia 99% (84/85) of the time. This study demonstrates a proof-of-concept of how noninvasive optical imaging can be used as a tool to study expression levels of multiple biomarkers and their heterogeneity across a large mucosal surface and how biomarker characteristics correlate with presence of neoplasia. Applications of this approach include predicting regions with the highest likelihood of disease, elucidating the role of biomarker heterogeneity in cancer biology, and identifying patients who will respond to targeted therapy.

Correlations between SUVmax and expression of GLUT1 and growth factors inducing lymphangiogenesis

RATIONALE AND OBJECTIVES

The purpose of this study was to assess the correlations between the maximum standardized uptake value (SUVmax) of colorectal carcinoma and hepatocyte growth factor (HGF), vascular endothelial growth factor C (VEGF-C), and their respective receptors using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT).

METHODS

Fluorine-18-FDG PET/CT scans were performed on 33 patients with colorectal carcinoma before any treatment. The SUVmax of colorectal carcinoma and the clinicopathologic data associated with lymphatic metastases were analyzed. The expression of glucose transporter 1 (GLUT1), HGF, c-Met, VEGF-C, and vascular endothelial growth factor receptor 3 (VEGFR-3) in tumor tissues was analyzed using immunohistochemical methods. Lymphatic endothelial cells were marked with D2-40, and lymphatic vessel density (LVD) was recorded. The correlations were analyzed among the SUVmax of colorectal carcinoma, LVD, and the expression of GLUT1, HGF, c-Met, VEGF-C, and VEGFR-3 in tumor tissues.

RESULTS

SUVmax and LVD in 15 patients with lymphatic metastases were 13.00 ± 4.51 and 6.25 ± 1.54, respectively, whereas in 18 patients with nonmetastatic nodes, SUVmax and LVD were 9.66 ± 4.82 and 4.54 ± 1.02, respectively. The differences of SUVmax and LVD between metastatic and nonmetastatic patients were statistically significant (F = 4.153, P = .025, and F = 14.501, P = .001, respectively). There were no statistical differences of SUVmax and LVD in variably differentiated colorectal carcinoma (F = 0.708, P = .502, and F = 0.311, P = .735, respectively). The expression rates of GLUT1 in neoplastic and normal tissue were 72.7% (24 of 33) and 21.2% (seven of 33), respectively (P = .001). Moreover, the expression rates of GLUT1 in metastatic and nonmetastatic tissue were 93.33% (14 of 15) and 61.11% (11 of 18), respectively (P = .038). LVD and the integrated optical density of GLUT1 were 5.31 ± 1.53 and 8.21 × 10(4) ± 4.30 × 10(4), respectively, in tumor tissue, and there were linear correlations between SUVmax and LVD (r = 0.373, P = .033) and between SUVmax and expression of GLUT1 (r = 0.428, P = .013). The differences of SUVmax in HGF, c-Met, and VEGF-C groups with different expressions were statistically significant (P = .007, P = .009, and P = .030, respectively). No correlation was found between the expression of VEGFR-3 and SUVmax. The expression of GLUT1 and HGF as well as of GLUT1 and VEGF-C was rank correlated (r = 0.521, P = .002, and r = 0.505, P = .003, respectively). No rank correlations were found between the expression of GLUT1 and c-Met, GLUT1, and VEGFR-3.

CONCLUSIONS

The SUVmax of colorectal carcinoma was significantly higher in metastatic patients; the uptake of colorectal carcinoma was associated with LVD and the expression of HGF and VEGF-C but not with the expression of VEGFR-3.

Role of FDG-PET as a biological marker for predicting the hypoxic status of tongue cancer

BACKGROUND

To determine whether 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) could serve as a useful technique predicting tumor hypoxia and prognosis in tongue cancer, we assessed the relationship between FDG uptake and the levels of hypoxia-related markers.

METHODS

Tumor uptake of FDG in 33 patients with T2 tongue cancer was assessed by measuring maximum standardized uptake values (SUVmax). Expression of hypoxia-inducible factor (HIF)-1α, carbonic anhydrase (CA)-9, glucose transporter (GLUT)-1, and erythropoietin receptor (EPOR), was determined by immunohistochemical staining. Correlation between SUVmax and the expression of hypoxia-related markers was assessed and multivariate analysis was performed to determine what parameters affected clinical outcomes.

RESULTS

We observed strong correlations between SUVmax and expression of HIF-1α (p < .05), CA-9 (p < .01), and GLUT-1 (p < .01). SUVmax, HIF-1α expression, and tumor grade were significant independent predictors of disease-free survival (DFS).

CONCLUSION

SUVmax may be a good noninvasive biomarker for prediction of hypoxic status and prognosis of patients with T2 tongue cancer.

Altered metabolism in head and neck squamous cell carcinoma: an opportunity for identification of novel biomarkers and drug targets

Tumor cells were first shown to exhibit a distinct metabolic phenotype over 80 years ago. Since then, it has become clear that multiple oncogenic events contribute to the development of a metabolic phenotype that supports rapid proliferation. Because this phenotype represents an essential component of tumorigenesis and disease progression, it also represents a potential source of biomarkers associated with aggressive disease. In addition, the addiction of tumor cells to specific nutrients and the up-regulation of key metabolic enzymes provide unique opportunities for pharmacologic manipulation. Despite the use of multimodality treatment, survival rates for patients with advanced head and neck squamous cell carcinoma (HNSCC) remain low, partially attributed to the development of drug resistance. In this review, we evaluate the role of altered HNSCC metabolism as both a source of novel biomarkers and a means to bypass resistance mechanisms to conventional forms of therapy.

Preclinical and clinical evidence that Deoxy-2-[18F]fluoro-D-glucose positron emission tomography with computed tomography is a reliable tool for the detection of early molecular responses to erlotinib in head and neck cancer

PURPOSE

There is a clinical need to identify predictive markers of the responses to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). Deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography with computed tomography ((18)FDG-PET/CT) could be a tool of choice for monitoring the early effects of this class of agent on tumor activity.

EXPERIMENTAL DESIGN

Using models of human head and neck carcinoma (CAL33 and CAL166 cell lines), we first tested in vitro and in vivo whether the in vivo changes in (18)FDG-PET/CT uptake were associated with the molecular and cellular effects of the EGFR-TKI erlotinib. Then, the pathologic and morphologic changes and the (18)FDG-PET/CT uptake before and after erlotinib exposure in patients were analyzed.

RESULTS

Erlotinib strongly inhibited extracellular signal-regulated kinase-1/2 (ERK-1/2) phosphorylation both in the preclinical models and in patients. Western blotting, immunofluorescence, and immunohistochemistry showed that erlotinib did not modify Glut-1 expression at the protein level either in cell line models or in tumor tissue from mouse xenografts or in patients. Phospho-ERK-1/2 inhibition was associated with a reduction in (18)FDG uptake in animal and human tumors. The biological volume was more accurate than the standardized uptake value for the evaluation of the molecular responses.

CONCLUSION

These results show that the (18)FDG-PET/CT response is a reliable surrogate marker of the effects of erlotinib in head and neck carcinoma.