Impact of aminopenicillin administration routes on antimicrobial effects of platelet-rich fibrin: An in-vitro investigation

INTRODUCTION

The aim of the study was to investigate the impact of different aminopenicillin administration routes on the antimicrobial effects of platelet-rich fibrin (PRF).

METHODS

We enrolled patients undergoing treatment with amoxicillin/clavulanic acid (AMC) orally or ampicillin/sulbactam (SAM) intravenously. AMC was applied in a single oral dose (875/125 mg), or in a double oral dose (1750/250 mg), and SAM in a dose of 2000/1000 mg. Blood was obtained one hour after the intake of AMC or 15 min after the infusion of SAM ended. Antimicrobial effects were investigated in agar diffusion tests with fresh PRF, PRF stored for 24, and PRF stored for 48 h. Agar diffusion tests were performed with Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Porphyromonas gingivalis. Inhibition zones (IZs) around a 6 mm PRF disc were measured after 24 h.

RESULTS

IZs for fresh PRF and the single oral dose of AMC were 0.0, 4.7, 15.2, 2.3, and 0.9 mm (E. coli, S. aureus, S. pneumoniae, H. influenzae, and P. gingivalis, respectively). For the double oral dose, these values were 0.0, 11.4, 20.0, 8.1, and 7.4 mm. IZs for SAM were 11.9, 18.2, 24.7, 20.3, and 22.1 mm. Differences between parenteral and oral application as well as between different oral doses were significant (p<0.0001, one-way ANOVA).

DISCUSSION

The results of our study demonstrate that oral administration is a suitable route to load PRF with these drugs. This could expand the scope of PRF application to prevent infections at the surgical site, especially in an outpatient setting in which drugs are normally applied orally.

Performance of cone-beam computed tomography (CBCT) in comparison to conventional computed tomography (CT) and magnetic resonance imaging (MRI) for the detection of bone invasion in oral squamous cell cancer (OSCC): a prospective study

BACKGROUND

Oral squamous carcinoma (OSCC) is often diagnosed at late stages and bone erosion or invasion of the jawbone is frequently present. Computed tomography (CT) and magnetic resonance imaging (MRI) are known to have high diagnostic sensitivities, specificities, and accuracies in detecting these bone affections in patients suffering from OSCC. To date, the existing data regarding the impact of cone-beam computed tomography (CBCT) have been weak. Therefore, this study aimed to investigate whether CBCT is a suitable tool to detect bone erosion or invasion in patients with OSCC.

METHODS

We investigated in a prospective trial the impact of CBCT in the diagnosis of bone erosion or invasion in patients with OSCC who underwent surgery. Every participant received a CBCT, CT, and MRI scan during staging. Imaging modalities were evaluated by two specialists in oral and maxillofacial surgery (CBCT) and two specialists in radiology (CT and MRI) in a blinded way, to determine whether a bone affection was present or not. Reporting used the following 3-point system: no bony destruction ("0"), cortical bone erosion ("1"), or medullary bone invasion ("2"). Histological examination or a follow-up served to calculate the sensitivities, specificities, and accuracies of the imaging modalities.

RESULTS

Our results revealed high diagnostic sensitivities (95.6%, 84.4%, and 88.9%), specificities (87.0%, 91.7%, and 91.7%), and accuracies (89.5%, 89.5%, and 90.8%) for CBCT, CT, and MRI. A pairwise comparison found no statistical difference between CBCT, CT, and MRI.

CONCLUSION

Our data support the routine use of CBCT in the diagnosis of bone erosion and invasion in patients with OSCC as diagnostic accuracy is equal to CT and MRI, the procedure is cost-effective, and it can be performed during initial contact with the patient.

Multimodal artificial intelligence-based pathogenomics improves survival prediction in oral squamous cell carcinoma

In this study, we aimed to develop a novel prognostic algorithm for oral squamous cell carcinoma (OSCC) using a combination of pathogenomics and AI-based techniques. We collected comprehensive clinical, genomic, and pathology data from a cohort of OSCC patients in the TCGA dataset and used machine learning and deep learning algorithms to identify relevant features that are predictive of survival outcomes. Our analyses included 406 OSCC patients. Initial analyses involved gene expression analyses, principal component analyses, gene enrichment analyses, and feature importance analyses. These insights were foundational for subsequent model development. Furthermore, we applied five machine learning/deep learning algorithms (Random Survival Forest, Gradient Boosting Survival Analysis, Cox PH, Fast Survival SVM, and DeepSurv) for survival prediction. Our initial analyses revealed relevant gene expression variations and biological pathways, laying the groundwork for robust feature selection in model building. The results showed that the multimodal model outperformed the unimodal models across all methods, with c-index values of 0.722 for RSF, 0.633 for GBSA, 0.625 for FastSVM, 0.633 for CoxPH, and 0.515 for DeepSurv. When considering only important features, the multimodal model continued to outperform the unimodal models, with c-index values of 0.834 for RSF, 0.747 for GBSA, 0.718 for FastSVM, 0.742 for CoxPH, and 0.635 for DeepSurv. Our results demonstrate the potential of pathogenomics and AI-based techniques in improving the accuracy of prognostic prediction in OSCC, which may ultimately aid in the development of personalized treatment strategies for patients with this devastating disease.

Investigation of clindamycin concentrations in human plasma and jawbone tissue in patients with osteonecrosis of the jaw: A prospective trial

The aim of this study was to investigate the jawbone concentration of clindamycin (CLI) in patients with an osteonecrosis of the jaw (ONJ). Patients with medication-related ONJ (MRONJ) and osteoradionecrosis (ORN) with an antibiotic treatment with CLI were included. Plasma, vital and necrotic bone samples were collected. Plasma and jawbone samples were analyzed by liquid chromatography-tandem mass spectrometry. Patients with MRONJ exhibited a mean plasma CLI concentration of 9.6 μg/mL (SD ± 3.6 μg/mL) and mean concentrations of 2.3 μg/g CLI (SD ± 1.4 μg/g) and 2.1 μg/g CLI (SD ± 2.4 μg/g) in vital and necrotic bone samples, without statistical significance (p = 0.79). In patients with ORN, mean concentration in plasma was 12.0 μg/mL (SD ± 2.6 μg/mL), in vital bone 2.1 μg/g (SD ± 1.5 μg/g), and in necrotic bone 1.7 μg/g (SD ± 1.2 μg/g). Vital and necrotic bone concentrations did not differ significantly (p = 0.88). The results demonstrate that CLI concentrations are considerably lower than in plasma, but sufficient for most bacteria present in ONJ. Within the limitations of the study, it seems that CLI is a relevant alternative to other antibiotics in the treatment of ONJ because it reaches adequate concentrations in jawbone.

Successful microvascular surgery in patients with thrombophilia in head and neck surgery: a case series

BACKGROUND

In this case series, a perioperative anticoagulation protocol for microvascular head and neck surgery in patients with thrombophilia is presented. Microvascular free-flap surgery is a standard procedure in head and neck surgery with high success rates. Nevertheless, flap loss-which is most often caused by thrombosis-can occur and has far-reaching consequences, such as functional impairment, prolonged hospitalization, and increased costs. The risk of flap loss owing to thrombosis is significantly increased in patients with thrombophilia. Therefore, perioperative anticoagulation is mandatory. To date, no perioperative anticoagulation protocol exists for these high-risk patients.

CASE PRESENTATION

We present three exemplary male Caucasian patients aged 53-57 years with free flap loss owing to an underlying, hidden thrombophilia.

CONCLUSION

We present a modified anticoagulation protocol for microvascular surgery in these high-risk patients, enabling successful microsurgical reconstruction.

Realizing in-house algorithm-driven free fibula flap set up within 24 hours: a pilot study evaluating accuracy with open-source tools

Objective

This study aims to critically evaluate the effectiveness and accuracy of a time safing and cost-efficient open-source algorithm for in-house planning of mandibular reconstructions using the free osteocutaneous fibula graft. The evaluation focuses on quantifying anatomical accuracy and assessing the impact on ischemia time.

Methods

A pilot study was conducted, including patients who underwent in-house planned computer-aided design and manufacturing (CAD/CAM) of free fibula flaps between 2021 and 2023. Out of all patient cases, we included all with postoperative 3D imaging in the study. The study utilized open-source software tools for the planning step, and three-dimensional (3D) printing techniques. The Hausdorff distance and Dice coefficient metrics were used to evaluate the accuracy of the planning procedure.

Results

The study assessed eight patients (five males and three females, mean age 61.75 ± 3.69 years) with different diagnoses such as osteoradionecrosis and oral squamous cell carcinoma. The average ischemia time was 68.38 ± 27.95 min. For the evaluation of preoperative planning vs. the postoperative outcome, the mean Hausdorff Distance was 1.22 ± 0.40. The Dice Coefficients yielded a mean of 0.77 ± 0.07, suggesting a satisfactory concordance between the planned and postoperative states. Dice Coefficient and Hausdorff Distance revealed significant correlations with ischemia time (Spearman's rho = -0.810, p = 0.015 and Spearman's rho = 0.762, p = 0.028, respectively). Linear regression models adjusting for disease type further substantiated these findings.

Conclusions

The in-house planning algorithm not only achieved high anatomical accuracy, as reflected by the Dice Coefficients and Hausdorff Distance metrics, but this accuracy also exhibited a significant correlation with reduced ischemia time. This underlines the critical role of meticulous planning in surgical outcomes. Additionally, the algorithm's open-source nature renders it cost-efficient, easy to learn, and broadly applicable, offering promising avenues for enhancing both healthcare affordability and accessibility.

Performance of artificial intelligence-based algorithms to predict prolonged length of stay after head and neck cancer surgery

Background

Medical resource management can be improved by assessing the likelihood of prolonged length of stay (LOS) for head and neck cancer surgery patients. The objective of this study was to develop predictive models that could be used to determine whether a patient's LOS after cancer surgery falls within the normal range of the cohort.

Methods

We conducted a retrospective analysis of a dataset consisting of 300 consecutive patients who underwent head and neck cancer surgery between 2017 and 2022 at a single university medical center. Prolonged LOS was defined as LOS exceeding the 75th percentile of the cohort. Feature importance analysis was performed to evaluate the most important predictors for prolonged LOS. We then constructed 7 machine learning and deep learning algorithms for the prediction modeling of prolonged LOS.

Results

The algorithms reached accuracy values of 75.40 (radial basis function neural network) to 97.92 (Random Trees) for the training set and 64.90 (multilayer perceptron neural network) to 84.14 (Random Trees) for the testing set. The leading parameters predicting prolonged LOS were operation time, ischemia time, the graft used, the ASA score, the intensive care stay, and the pathological stages. The results revealed that patients who had a higher number of harvested lymph nodes (LN) had a lower probability of recurrence but also a greater LOS. However, patients with prolonged LOS were also at greater risk of recurrence, particularly when fewer (LN) were extracted. Further, LOS was more strongly correlated with the overall number of extracted lymph nodes than with the number of positive lymph nodes or the ratio of positive to overall extracted lymph nodes, indicating that particularly unnecessary lymph node extraction might be associated with prolonged LOS.

Conclusions

The results emphasize the need for a closer follow-up of patients who experience prolonged LOS. Prospective trials are warranted to validate the present results.

Investigation of three common centrifugation protocols for platelet-rich fibrin (PRF) as a bio-carrier for ampicillin/sulbactam: a prospective trial

OBJECTIVES

Different platelet-rich fibrin (PRF) protocols exist and are known to differ in resulting mechanical and bioactive properties. Centrifugation parameters may also influence drug release, in particular antibiotics, when using PRF as a bio-carrier. We thus evaluated three common protocols regarding effects on the bio-carrier properties.

MATERIALS AND METHODS

In a prospective trial comprising 33 patients, we compared different protocols for PRF as a bio-carrier for ampicillin/sulbactam (SAM). Blood samples were taken shortly after a single dose of ampicillin/sulbactam (2 g/1 g) was administered to patients intravenously. PRF was obtained by centrifugation and three protocols were used: protocol A (1300 rpm, 8 min, RCF-max = 208 g), B (2300 rpm, 12 min, RCF-max = 652 g), and C (1500 rpm, 14 min, RCF-max = 276 g). The antibacterial activity of PRF was investigated against five oral species in vitro, based on agar diffusion methodology.

RESULTS

The study demonstrates that a single dose of SAM is sufficient to reach high concentrations in PRF in all protocols (150 µg/ml), which is comparable to the plasma SAM concentration. Antibacterial activity was inferred from the diameter of inhibition zones seen in agar diffusion tests using PRF discs. Protocol B resulted in the largest inhibition zones. One-way ANOVA revealed statistically improved results for protocol B for some bacteria.

CONCLUSIONS

The study provides valuable data on PRF antibiotic enrichment, notably SAM. A single dose of SAM is sufficient to reach clinically relevant concentrations in PRF.

CLINICAL RELEVANCE

These findings potentially extend the application of PRF, for example in patients with osteonecrosis of the jaw or in oral surgery (e.g., stick bone).

Bone Concentration of Ampicillin/Sulbactam: A Pilot Study in Patients with Osteonecrosis of the Jaw

Osteonecrosis of the jaw (ONJ) occurs typically after irradiation of the head and neck area or after the intake of antiresorptive agents. Both interventions can lead to compromised bone perfusion and can ultimately result in infection and necrosis. Treatment usually consists of surgical necrosectomy and prolonged antibiotic therapy, usually through beta-lactams such as ampicillin/sulbactam. The poor blood supply in particular raises the question as to whether this form of antibiosis can achieve sufficient concentrations in the bone. Therefore, we investigated the antibiotic concentration in plasma and bone samples in a prospective study. Bone samples were collected from the necrosis core and in the vital surrounding bone. The measured concentrations in plasma for ampicillin and sulbactam were 126.3 ± 77.6 and 60.2 ± 35.0 µg/mL, respectively. In vital bone and necrotic bone samples, the ampicillin/sulbactam concentrations were 6.3 ± 7.8/1.8 ± 2.0 µg/g and 4.9 ± 7.0/1.7 ± 1.7 µg/g, respectively. These concentrations are substantially lower than described in the literature. However, the concentration seems sufficient to kill most bacteria, such as Streptococci and Staphylococci, which are mostly present in the biofilm of ONJ. We, therefore, conclude that intravenous administration of ampicillin/sulbactam remains a valuable treatment in the therapy of ONJ. Nevertheless, increasing resistance of Escherichia coli towards beta-lactam antibiotics have been reported and should be considered.

Oral-Health-Related Quality of Life in Patients with Medication-Related Osteonecrosis of the Jaw: A Prospective Clinical Study

Medication-related osteonecrosis of the jaw (MRONJ) represents an adverse side effect of antiresorptive and antiangiogenic medications. It is associated with impaired quality of life, oral health, and oral function and can be classified into various stages. The purpose of this prospective clinical study is to evaluate the impact of stages I and II MRONJ on oral-health-related quality of life (OHRQoL) and related parameters. Patients' OHRQoL, satisfaction with life, oral discomfort, and oral health were assessed using the German version of the Oral Health Impact Profile (OHIP-G49), visual analog scales (VAS), and Satisfaction with Life Scale (SWLS) at baseline (T0), 10 days (T1), and 3 months after treatment (T2) in 36 patients. Data were analyzed using Kolmogorov-Smirnov test, two-way mixed ANOVAs, and follow-up Mann-Whitney U tests. The impact of treatment effects on the original seven OHIP domain structures and the recently introduced four-dimensional OHIP structure were evaluated using linear regression analysis. Thirty-six patients received surgical MRONJ treatment. Before treatment, patients' perceived OHRQoL, oral discomfort, oral health, and satisfaction with life were negatively affected by MRONJ. Surgical treatment significantly improved OHRQoL and related parameters (all p ≤ 0.012). This improvement was greater in patients with higher impairment at T0. OHRQoL and oral restrictions were still impaired after treatment in patients who needed prosthetic treatment. The four-dimensional structure revealed valuable information beyond the standard seven OHIP domains. Increased awareness of MRONJ risks and an interdisciplinary treatment approach for MRONJ patients are needed.

PKM2 Modulation in Head and Neck Squamous Cell Carcinoma

The enzyme pyruvate kinase M2 (PKM2) plays a major role in the switch of tumor cells from oxidative phosphorylation to aerobic glycolysis, one of the hallmarks of cancer. Different allosteric inhibitors or activators and several posttranslational modifications regulate its activity. Head and neck squamous cell carcinoma (HNSCC) is a common disease with a high rate of recurrence. To find out more about PKM2 and its modulation in HNSCC, we examined a panel of HNSCC cells using real-time cell metabolic analysis and Western blotting with an emphasis on phosphorylation variant Tyr105 and two reagents known to impair PKM2 activity. Our results show that in HNSCC, PKM2 is commonly phosphorylated at Tyrosine 105. Its levels depended on tyrosine kinase activity, emphasizing the importance of growth factors such as EGF (epidermal growth factor) on HNSCC metabolism. Furthermore, its correlation with the expression of CD44 indicates a role in cancer stemness. Cells generally reacted with higher glycolysis to PKM2 activator DASA-58 and lower glycolysis to PKM2 inhibitor Compound 3k, but some were more susceptible to activation and others to inhibition. Our findings emphasize the need to further investigate the role of PKM2 in HNSCC, as it could aid understanding and treatment of the disease.

Targeting fibroblast activation protein in newly diagnosed squamous cell carcinoma of the oral cavity - initial experience and comparison to [18F]FDG PET/CT and MRI

Purpose

While [¹⁸F]-fluorodeoxyglucose ([¹⁸F]FDG) is the standard for positron emission tomography/computed tomography (PET/CT) imaging of oral squamous cell carcinoma (OSCC), diagnostic specificity is hampered by uptake in inflammatory cells such as neutrophils or macrophages. Recently, molecular imaging probes targeting fibroblast activation protein α (FAP), which is overexpressed in a variety of cancer-associated fibroblasts, have become available and might constitute a feasible alternative to FDG PET/CT.

Methods

Ten consecutive, treatment-naïve patients (8 males, 2 females; mean age, 62 ± 9 years) with biopsy-proven OSCC underwent both whole-body [¹⁸F]FDG and [⁶⁸Ga]FAPI-04 (FAP-directed) PET/CT for primary staging prior to tumor resection and cervical lymph node dissection. Detection of the primary tumor, as well as the presence and number of lymph node and distant metastases was analysed. Intensity of tracer accumulation was assessed by means of maximum (SUV_max) and peak (SUV_peak) standardized uptake values. Histological work-up including immunohistochemical staining for FAP served as standard of reference.

Results

[¹⁸F]FDG and FAP-directed PET/CT detected all primary tumors with a SUV_max of 25.5 ± 13.2 (FDG) and 20.5 ± 6.4 (FAP-directed) and a SUV_peak of 16.1 ± 10.3 ([¹⁸F]FDG) and 13.8 ± 3.9 (FAP-directed), respectively. Regarding cervical lymph node metastases, FAP-directed PET/CT demonstrated comparable sensitivity (81.3% vs. 87.5%; P = 0.32) and specificity (93.3% vs. 81.3%; P = 0.16) to [¹⁸F]FDG PET/CT. FAP expression on the cell surface of cancer-associated fibroblasts in both primary lesions as well as lymph nodes metastases was confirmed in all samples.

Conclusion

FAP-directed PET/CT in OSCC seems feasible. Future research to investigate its potential to improve patient staging is highly warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05422-z.

Accuracy of 18-F Fluorodeoxyglucose Positron Emission Tomographic/Computed Tomographic Imaging in Primary Staging of Squamous Cell Carcinoma of the Oral Cavity

IMPORTANCE

Squamous cell carcinoma (SCC) of the oral cavity is one of the most common tumor entities worldwide. Precise initial staging is necessary to determine a diagnosis, treatment, and prognosis.

OBJECTIVE

To examine the diagnostic accuracy of preoperative 18-F fluorodeoxyglucose (FDG) positron emission tomographic/computed tomographic (PET/CT) imaging in detecting cervical lymph node metastases.

DESIGN, SETTING, AND PARTICIPANTS

This prospective diagnostic study was performed at a single tertiary reference center between June 1, 2013, and January 31, 2016. Data were analyzed from April 7, 2018, through May 31, 2019. Observers of the FDG PET/CT imaging were blinded to patients' tumor stage. A total of 150 treatment-naive patients with clinical suspicion of SCC of the oral cavity were enrolled.

EXPOSURES

All patients underwent FDG PET/CT imaging before local tumor resection with selective or complete neck dissection.

MAIN OUTCOMES AND MEASURES

The accuracy of FDG PET/CT in localizing primary tumor, lymph node, and distant metastases was tested. Histopathologic characteristics of the tissue samples served as the standard of reference.

RESULTS

Of the 150 patients enrolled, 135 patients (74 [54.8%] men) with a median age of 63 years (range, 23-88 years) met the inclusion criteria (histopathologically confirmed primary SCC of the oral cavity/level-based histopathologic assessment of the resected lymph nodes). Thirty-six patients (26.7%) in the study cohort had neck metastases. Use of FDG PET/CT detected cervical lymph node metastasis with 83.3% sensitivity (95% CI, 71.2%-95.5%) and 84.8% specificity (95% CI, 77.8%-91.9%) and had a negative predictive value of 93.3% (95% CI, 88.2%-98.5%). The specificity was higher than for contrast-enhanced cervical CT imaging (67.0%; 95% CI, 57.4%-76.7%; P < .01) and cervical magnetic resonance imaging (62.6%; 95% CI, 52.7%-72.6%; P < .001). Ipsilateral lymph node metastasis in left- or right-sided primary tumor sites was detected with 78.6% sensitivity (95% CI, 63.4%-93.8%) and 83.1% specificity (95% CI, 75.1%-91.2%), and contralateral metastatic involvement was detected with 66.7% sensitivity (95% CI, 28.9%-100.0%) and 98.6% specificity (95% CI, 95.9%-100.0%). No distant metastases were observed.

CONCLUSIONS AND RELEVANCE

In this study, FDG PET/CT imaging had a high negative predictive value in detecting cervical lymph node metastasis in patients with newly diagnosed, treatment-naive SCC of the oral cavity. Routine clinical use of FDG PET/CT might lead to a substantial reduction of treatment-related morbidity in most patients.

Sensitization of head and neck squamous cell carcinoma to apoptosis by combinational SMAC mimetic and Fas ligand-Fc treatment in vitro

This study aimed to investigate the in vitro efficacy of three different SMAC mimetics for pro-apoptotic sensitization of HNSCC cells. We evaluated BV-6 in comparison to Birinapant and LCL161, for which pro-apoptotic sensitization effects have been demonstrated. Concentration-dependent response was measured for BV-6 in each cell line with an average IC₅₀ value 8-fold lower than of aforementioned SMAC mimetics. Combination treatment of FasL (log2) and BV-6 (IC₁₀) showed highly significant cell count reductions even in the lowest applied concentration in five cell lines (PCI-1: p = 0.0002, PCI-13: p = 0.0002, Detroit 562: p: p < 0.0001, FaDu: p < 0.0001, SCC-25: p = 0.0047). Synergistic effects (y < 1) were evident in eight out of 10 cell lines (PCI-1, PCI-9, PCI-13, PCI-68, Detroit 562, FaDu, SCC-25 and HaCaT). Annexin V assays revealed in nine cell lines very highly significant (p < 0.001) pro-apoptotic effects of BV-6. Western blots showed a heterogeneous IAP expression following SMAC mimetic treatment. Except for two cell lines, at least the cellular inhibitor of apoptosis protein 1 (cIAP1) was degraded in response to BV-6. For prospective targeted HNSCC therapy, this study identifies SMAC mimetics, particularly BV-6 as the compound with the highest pro-apoptotic potency, as promising antitumor agents.

Multi-kinase inhibitors and cisplatin for head and neck cancer treatment in vitro

Multidrug resistance (MDR) remains one of the major causes of suboptimal outcome following therapy in head and neck squamous cell carcinoma (HNSCC). ATP-binding cassette (ABC) transporters are overexpressed in HNSCC, which contributes to the limited effect of chemotherapeutic treatment. In addition to their named function, tyrosine kinase inhibitors (TKIs) have been revealed to impact on ABC transporter activity and expression. Therefore, the present study aimed to investigate the effects of combination therapy using different TKIs combined with cisplatin. Reverse transcription-quantitative PCR was used to characterize ABC transporter and receptor expression in 5 HNSCC cell lines treated with 3 different TKIs (pazopanib, dovitinib, nintedanib) and cisplatin. Treatment efficacy was analyzed using a crystal violet staining assay. Analysis of ABC transporter (ABCB1, ABCC1 and ABCG2) genetic alterations was performed using The Cancer Genome Atlas. Statistical analysis was conducted to evaluate the effects of mono- and combination treatment. With the exception of ABCB1, all of the investigated ABC transporters were expressed in each cell line. The additive effects of TKI + cisplatin combination treatment were observed for pazopanib in three cell lines, nintedanib in four cell lines, and were not observed for dovitinib in any of the cell lines investigated. The combination of multi-kinase inhibitors and conventional chemotherapy in HNSCC may strengthen the use of current therapeutic strategies; nintedanib appears to be the most suitable TKI for combination therapy. Further efforts are required to classify TKI efficacy with regard to cisplatin resistance.

Osteoporosis therapy in patients with inflammatory rheumatic diseases and osteonecrosis of the jaw

BACKGROUND AND OBJECTIVES

The aim of the present study was to assess the prevalence of medication-related osteonecrosis of the jaw (MRONJ) in osteoporosis patients suffering from inflammatory rheumatic diseases, as well as to assess the prevalence of relevant dental, behavioral, and medical risk factors for MRONJ.

MATERIALS AND METHODS

A total of 198 patients with inflammatory rheumatic diseases and osteoporosis therapy were recruited from a tertiary rheumatological/immunological referral center between June 2015 and September 2016. They were assessed using a structured interview. A maxillofacial surgeon later examined patients complaining of possible symptoms of osteonecrosis. In cases of osteonecrosis, dental records were obtained and evaluated. Preventive measures taken and dental as well as other clinical risk factors were evaluated.

RESULTS

Of the 198 patients, three suffered from osteonecrosis of the jaw, none of whom had any history of malignant disease or radiation therapy, resulting in a prevalence of 1.5%. Of these three patients, only one was given bisphosphonates intravenously (i.v.), whereas all three had been treated orally. All three diagnoses of MRONJ had been previously known to the patients and their maxillofacial surgeons. Two of the patients had rheumatoid arthritis, and one patient suffered from large vessel vasculitis. Long anti-osteoporotic treatment duration, low functional status, and low bone density of the femur were significantly associated with MRONJ development.

CONCLUSION

Inflammatory rheumatic diseases constitute a risk factor for MRONJ in patients treated with bisphosphonates for osteoporosis. Patients should be counseled accordingly and should be offered dental screening and regular dental check-ups.

MicroRNA expression correlates with disease recurrence and overall survival in oral squamous cell carcinoma

OBJECTIVES

Locoregional disease recurrence and metastatic events are the leading causes of death and the most important prognostic factors in patients with head and neck squamous cell carcinoma (HNSCC). A major goal of oncology is the identification of clinical and molecular parameters to evaluate the individual risk of recurrence. MicroRNAs (miRNAs) have been shown to correlate well with tumor size and differentiation. Therefore, they are candidate biomarkers for estimating clinical outcomes.

MATERIALS AND METHODS

In this study, the expression levels of distinct miRNAs extracted from formalin-fixed, paraffin-embedded (FFPE) samples of oral squamous cell carcinoma were compared.

RESULTS

Statistical analysis revealed significant correlations between distinct miRNAs and disease recurrence (miR-99*, miR-194*; p < 0.05) and overall survival (miR-99*; p < 0.05). The results were then validated via data from The Cancer Genome Atlas (TCGA).

CONCLUSIONS

Our data show that miR-99* and miR-194* can possibly serve as biomarkers for clinical outcome in HNSCC. These findings may help to identify high-risk patients, who could profit from a more individualized treatment and follow-up.

Apoptosis-sensitizing activity of birinapant in head and neck squamous cell carcinoma cell lines

Inhibitor of apoptosis proteins, which are overexpressed in head and neck squamous cell carcinoma (HNSCC), may cause therapeutic resistance. Using SMAC mimetic compounds, including birinapant, to degrade and/or inhibit these proteins and sensitize apoptosis may enhance therapies in HNSCC. Fas expression was analyzed in nine HNSCC cell lines and one keratinocyte cell line via flow cytometry. These cell lines were treated with Fas ligand-Fc (FasL) and birinapant, a bivalent SMAC mimetic, in mono and combination therapies. Cytotoxicity was measured using a crystal violet assay. Annexin V assay was performed for detection of apoptosis. The treatment efficacy of mono and combination therapies was statistically analyzed. Nonlinear regression analysis was performed to determine the inhibitory concentration (IC₁₀) of birinapant. Fas expression was detected in each cell line tested. Mono treatment with FasL revealed minor to no apoptotic effects in the majority of the cell lines. Crystal violet and Annexin V staining revealed increased apoptosis rates for all cell lines following incubation with birinapant in mono treatment. Combination treatment with FasL and birinapant (IC₁₀) revealed additional and synergistic effects in eight out of the ten cell lines. To the best of our knowledge, the present study provided the first evidence of the apoptosis-sensitizing activity of combination treatment with FasL and birinapant in HNSCC cell lines.

Nutrition management for head and neck cancer patients improves clinical outcome and survival

Up to 80% of patients with head and neck cancers are malnourished because of their lifestyle and the risk factors associated with this disease. Unfortunately, nutrition management systems are not implemented in most head and neck cancer clinics. Even worse, many head and neck surgeons as well as hospital management authorities disregard the importance of nutrition management in head and neck cancer patients. In addition, the often extensive resection and reconstruction required for tumors in the upper aerodigestive tract pose special challenges for swallowing and sufficient food intake, placing special demands on nutrition management. This article presents the basics of perioperative metabolism and nutrition management of head and neck cancer patients and makes recommendations for clinical practice. Implementing a nutrition management system in head and neck cancer clinics will improve the clinical outcome and the survival of the patients.

Targeting VEGFR and FGFR in head and neck squamous cell carcinoma in vitro

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease characterized by a tumor microenvironment (TME) that overexpresses vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), which can lead to neovascularization, tumor growth and metastasis. Therapeutic strategies inhibiting these signaling pathways might lead to innovative HNSCC treatments. Five HNSCC cell lines were characterized based on VEGFR1-3 and FGFR1-4 expression by sqRT-PCR and treated with three different tyrosine kinase inhibitors (TKIs) (nintedanib, dovitinib and pazopanib), all of which are effective against VEGFR and FGFR family members. Crystal violet assays were performed to analyze the effect of the treatments on cell growth (viability). Additionally, VEGFR1-3 and FGFR1-4 expression data were retrieved from The Cancer Genome Atlas (TCGA), and statistical analyses were performed to investigate the receptor expression level in the different cell lines and the efficacy of the single-agent treatments. A correlation analysis was performed to quantify the degree of relationship between receptor expression and drug efficacy. With the exception of VEGFR2, the targeted receptors were expressed at different levels in all of the cell lines. The cell lines exhibited concentration-dependent responses with cell line-specific differences toward two of the three TKIs (nintedanib and dovitinib). Notably, all of the cell lines were resistant to pazopanib. TKIs have potential as therapeutic agents for HNSCC. Cell line-specific differences were observed in our in vitro experiments. The observed pazopanib resistance could be explained by receptor expression. Further investigation is required to determine TKI efficacy in HNSCC.

Mandibular intraosseous pseudocarcinomatous hyperplasia: a case report

Background

Mandibular pseudocarcinomatous hyperplasia is a rare and generally benign pathology. We report on one of these rare cases.

Case presentation

The case history of a 73-year-old white man stated that he had a carcinoma of the oropharynx, which was primarily treated with radiotherapy and chemotherapy 4 years prior. As a result of radiotherapy he developed an osteoradionecrosis of his mandible and a consecutive pathological fracture of his left mandibular angle. Subsequent osteosynthesis was performed with a reconstruction plate. When we first saw him, his reconstruction plate was partially exposed with intraoral and extraoral fistulation. The resected bone of his defect-bordering jaw showed the typical pathohistological findings of an intraosseous mandibular pseudocarcinomatous hyperplasia. After a first reconstruction attempt with an iliac crest graft failed, definitive reconstruction of his mandible with a microvascular anastomosed fibula graft was achieved.

Conclusions

Intraosseous pseudocarcinomatous hyperplasia of the mandible is a rare differential diagnosis in maxillofacial surgery. Besides other benign epithelial neoplasms, such as calcifying epithelial odontogenic tumor, squamous odontogenic tumor, or different forms of ameloblastoma, the far more frequent invasive squamous cell carcinoma needs to be excluded. A misinterpretation of pseudocarcinomatous hyperplasia as squamous cell carcinoma must be avoided because it can lead to a massive overtreatment.

The prognostic value of GLUT-1 staining in the detection of malignant transformation in oral mucosa

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) ranks as the sixth most common tumor entity worldwide. Unfortunately, the multimodal treatment consisting of surgery, radiation, and chemotherapy does not show the desired efficacy. The intent of this study was to evaluate the sensitivity and specificity of an oral brush biopsy in combination with glucose transporter (GLUT)-1 staining in identifying premalignant and malignant lesions.

METHODS

A total of 72 patients were included in the study, divided into four diagnostic subgroups (24 healthy, 15 carcinoma, 18 leukoplakia, 15 oral lichen planus). Oral brush biopsies were taken and analyzed for GLUT-1 expression by immunocytologic staining. Incisional biopsy served as the gold standard.

RESULTS

Twelve (80 %) of the 15 carcinomas, nine (50 %) of the 18 leukoplakia, nine (60 %) of the 15 oral lichen planus, and none of the healthy specimens stained positive for GLUT-1. This resulted in a sensitivity rate of 80 % and a specificity rate of 68.42 %. Diagnostic accuracy was 70.83 % based on the correct diagnoses in 51 of 72 patients.

CONCLUSION

An oral brush biopsy can easily be performed throughout the entire oral cavity, is noninvasive, and shows high sensitivity and specificity rates with conventional cytology or computer-assisted analysis.

CLINICAL RELEVANCE

The significance of GLUT-1-specific staining with an oral brush biopsy is more limited than expected but could be used as an additional tool in detecting malignant transformation in the oral cavity.

Contrary melanoma-associated antigen-A expression at the tumor front and center: A comparative analysis of stage I and IV head and neck squamous cell carcinoma

There is a growing body of evidence indicating that several melanoma-associated antigen-A (MAGE-A) subgroups contribute to the malignancy of head and neck cancer. The present study retrospectively analyzed the expression of all known MAGE-A subgroups in the tumor front and center of 38 head and neck cancer patients (Union for International Cancer Control stage I or IV) by immunohistochemistry. MAGE-A1, -A6, -A8, -A9 and -A11 were expressed at significantly higher levels at the tumor front of stage IV specimens compared with the tumor front of stage I specimens. In stage I cancer, the tumor center and front ratio (C/F ratio) for each subgroup was >1.0. In stage IV cancer, the C/F ratio was <1.0 in 9/11 subgroups. The most significant change in the expression pattern was observed for MAGE-A11. These results indicated that there is a marked alteration and shift to the invasive front of almost all MAGE-A subgroups, but particularly MAGE-A11, during the progression of head and neck squamous cell carcinoma.

Cytotoxic effects of SMAC-mimetic compound LCL161 in head and neck cancer cell lines

OBJECTIVES

Head and neck squamous cell carcinoma (HNSCC) is one of the most common tumor entities worldwide. Unfortunately, recent drug developments in other fields of oncology have yielded no efficacy in the treatment of oral squamous cell carcinoma. As a new starting point, we investigated the impact of Fas ligand (FasL) and the SMAC-mimetic compound LCL161 in mono- and combination treatment in HNSCC cell lines.

METHODS

Five different cell lines of HNSCC were treated with FasL and LCL161 in mono- and combination treatment. Cytotoxicity was measured via a crystal violet assay. The cell lines were characterized for CD95 (FasL receptor) expression via flow cytometry. The degradation of cellular inhibitor of apoptosis protein 1 (cIAP1) was detected via Western blot.

RESULTS

Incubation with FasL led to a significant decrease in three out of five cell lines. Combination treatment with LCL161 enhanced cytotoxicity significantly. Two cell lines were FasL resistant, but one of them could be resensitized with LCL161. In all cell lines, Western blot analysis showed degradation of cIAP1 after LCL161 application. However, one cell line showed only minor vulnerability to the FasL and LCL161 combination.

CONCLUSION

This is the first study investigating combination treatment of FasL and LCL161 in head and neck cancer cell lines. Pro-apoptotic effects of the combination were detected in the majority of the cell lines. Interestingly, one of two FasL-resistant cell lines was sensitive to the combination therapy with FasL and LCL161.

CLINICAL RELEVANCE

SMAC-mimetic compounds show promising results in the treatment of other tumor entities in vitro and might be useful drugs to improve HNSCC therapy.

Expression of MAGE-A1-A12 subgroups in the invasive tumor front and tumor center in oral squamous cell carcinoma

MAGE-A proteins are highly expressed in oral squamous cell carcinoma (OSCC) and are promising targets for cancer immunotherapy. This study examined the presence of MAGE-A expression within the tumor center (TC) and tumor invasive front (TIF) and evaluated its relationship to poor prognosis. The expression rate of each MAGE-A subtype, A1-A12, was examined in 68 OSCCs at the TIF and TC. Slides (1-µm) of tissue microarrays (diameter =0.6 mm) were immunohistochemically stained, and the findings were correlated to clinical data. Approximately 95% of the tumors had MAGE-A expression. Higher expression in the TC was shown significantly for MAGE-A1, -A5, -A6, -A9 and -A12 (P<0.05). MAGE-A2 and -A3 exhibited the opposite behavior (not significant, P>0.05). Age, tumor size, grade and survival time were not associated with the expression of certain MAGE-A subgroups. When expression in the whole tumor tissue was considered, only MAGE-A1 was expressed at a significantly higher rate in male patients (P=0.034). At the TIF, MAGE-A9 and the UICC disease stage were significantly correlated (P=0.0263), and MAGE-A6 and the UICC disease stage exhibited a strong trend (P=0.0596). The expression of MAGE-A3, -A4, -A5, -A9 and -A11 was significantly associated with lymph node metastasis, while MAGE-A4 was expressed in all regions of the tumors (TIF and TC). This study showed that higher expression of most MAGE-A antigens occurred at the TC rather than at the TIF. MAGE‑A1, -A3, -A4, -A5, -A9 and -A11 were significantly associated with clinically advanced stages of disease and seem to be of particular interest.

Co-treatment of wild-type EGFR head and neck cancer cell lines with afatinib and cisplatin

Treatment of head and neck squamous cell carcinoma (HNSCC) remains challenging. Non‑surgical approaches typically comprise radiotherapy and antineoplastic chemotherapy, of which platinum‑based agents are the most common. Similar to other malignancies, targeted therapies have an increasing role in the treatment of head and neck cancer. The overexpression of epidermal growth factor receptor (EGFR) is a useful target for specific therapeutic strategies. Resistance to EGFR‑directed therapies, including cetuximab, is partly mediated by the activation of alternative receptors and pathways. Therefore, other members of the ErbB family, including human epidermal growth factor receptor (HER)2 and HER4, may have important therapeutic roles. The aim of the present study was to investigate the efficacy of afatinib, an EGFR/HER2/HER4 tyrosine kinase inhibitor, in combination with cisplatin in HNSCC cell lines. The cisplatin concentration used was set at cell line‑specific half maximal inhibitory concentration values. Since the vast majority of head and neck cancers do not exhibit any EGFR tyrosine kinase domain mutations, five human EGFR wild‑type HNSCC cell lines were used in the present study. For statistical analyses, non‑parametric Mann‑Whitney tests were conducted. The present study detected a concentration‑dependent efficacy of afatinib. In three out of the five cell lines (PCI‑9, PCI‑52 and PCI‑68), 0.625 µM afatinib in combination with cisplatin exerted significant antiproliferative effects. In the two other cell lines (PCI‑1 and PCI‑13), significant effects were observed following treatment with ≥1.25 µM afatinib. Notably, compared with the findings of previous studies, cell lines (PCI-9 and PCI-52) less vulnerable to erlotinib or gefitinib were more vulnerable to the afatinib/cisplatin combination, and vice versa. Differences in the treatment success of erlotinib/gefitinib (targeting only EGFR) and afatinib (targeting EGFR, HER2 and HER4) may be explained by mutations in the EGFR. Therefore, afatinib treatment may be considered an important therapeutic option for patients failing cetuximab treatment. In addition, the present study demonstrated significant enhancement of platinum‑based therapies upon the addition of various afatinib concentrations. These results provide preclinical evidence to advocate further in vivo studies and clinical trials.

Oral brush biopsy and melanoma-associated antigens A (MAGE-A) staining in clinically suspicious lesions

PURPOSE

In oral cancer and in other tumor entities, melanoma-associated antigens are present. These antigens contribute to tumor progression and poor prognosis, and reduce the cytotoxicity of antineoplastic drugs. The aim of this study was to investigate the diagnostic potential of these antigens in combination with oral brush biopsies.

MATERIAL AND METHODS

We analyzed 72 oral brush biopsy specimens for melanoma-associated antigens A (MAGE-A) expression by immunocytologic staining with the MAGE-A 57B antibody. A total of 24 healthy specimens, 15 lichen ruber cases, 18 leukoplakia cases, and 15 invasive carcinomas were studied. Incisional biopsy served as the gold standard.

RESULTS

In total, 66 of 72 specimens (91.6%) could be assessed. Twelve of 15 (80%) carcinomas stained positive for MAGE-A. MAGE-A staining was detected in four of 51 nonmalignant specimens, resulting in a false-positive rate of 7.8%. However, MAGE-A positive staining was significantly correlated with oral squamous cell carcinoma (p < 0.0005). Sensitivity and specificity for MAGE-A staining and carcinoma were 80% and 92.2%, respectively. The diagnostic accuracy was 89.4%.

CONCLUSION

Our results indicate that oral brush biopsy with MAGE-A staining serves as an additional tool for use in oral cancer diagnosis. These findings might help to facilitate an easier and more representative surveillance of the mucosa, particularly for large areas of altered mucosa.

Melanoma-associated antigen expression and the efficacy of tyrosine kinase inhibitors in head and neck cancer

Melanoma-associated antigen (MAGE) has been identified in a variety of types of cancer. The expression of several MAGE subgroups is correlated with poor prognosis and chemotherapeutic resistance. One target of chemotherapeutic treatment in head and neck cancer is the epidermal growth factor receptor (EGFR). The efficacy of tyrosine kinase inhibitors (TKI) in the context of melanoma-associated antigens is discussed in the present study. Five human squamous cell carcinoma cell lines were treated with the EGFR TKIs, erlotinib and gefitinib. The efficacy of these agents was measured using a crystal violet assay. Furthermore, the expression levels of MAGE-A1, -A5, -A8, -A9, -A11 and -A12 were determined by reverse transcription-quantitative polymerase chain reaction. The association between TKI efficacy and MAGE-A expression was analyzed by linear regression. The cell lines revealed inhomogeneous expression patterns for the MAGE-A subgroups. Four of the five cell lines demonstrated a good response to erlotinib and gefitinib. However, treatment with erlotinib induced better results than those of gefitinib, and revealed a concentration-dependent effect. The expression of MAGE-A5 and -A11 were significantly correlated with lower efficacy of erlotinib and gefitinib. By contrast, MAGE-A12 was associated with a superior response to these two drugs. One cell line, which expressed all investigated MAGE-A subgroups, was entirely resistant to the two TKIs. These results revealed a notable correlation between MAGE-A5 and -A11 and lower efficacy of EGFR TKIs. Pretreatment analysis of MAGE-A status may therefore aid improvement of chemoprevention using erlotinib and gefitinib in head and neck cancer.

MAGE-A expression clusters and antineoplastic treatment in head and neck cancer

The nonsurgical treatment of head and neck squamous cell carcinoma (HNSCC) usually consists of radiation and chemotherapy. In general, the treatment efficacy of chemotherapy in head and neck cancer is limited. Apart from the placenta, testis and fetal keratinocytes, melanoma-associated antigens-A (MAGE-A) are only found in malignancies. Even though their molecular role remains unclear, several subgroups have been found to contribute to resistance to different chemotherapeutic agents. In the present study, established human squamous cell carcinoma cell lines were incubated with various concentrations of cisplatin, 5-fluorouracil, paclitaxel, docetaxel, cetuximab and panitumumab for 5, 10, 20 and 40 h. The treatment efficacy was measured dynamically by real-time cell analysis (RTCA). In addition, we determined the expression of all known MAGE-A subgroups (MAGE-A1 to MAGE-A12, excluding pseudogene MAGE-A7) by reverse transcription quantitative polymerase chain reaction. Of note, one cell line showed only a marginal expression of MAGE-A antigens, whereas another cell line showed a distinct expression of almost all the MAGE-A subgroups. The expression pattern varied in the other cell lines. MAGE-A4 was the most highly expressed of all the subgroups, and MAGE-A8 could not be detected. With the exception of MAGE-A6, -A8, -A9 and -A10, the expression levels differed significantly between the cell lines. Factor analysis suggested simplifying the MAGE-A expression level into two groups. Spearman's rank correlation revealed a significant association between MAGE-A expression and treatment efficacy for 20.8% (25/120) of the experiments. In 100% of these cases (25/25), Spearman's Rho revealed a positive correlation between clustered MAGE-A expression and poor treatment efficacy. Our data highlight the fact that higher a MAGE-A expression correlates with a poorer outcome of antineoplastic treatment. Clustered MAGE-A expression analysis may help to identify patients who are at a higher risk of antineoplastic treatment failure.

Influence of epidermal growth factor receptor expression on the cetuximab and panitumumab response rates of head and neck carcinoma cells

OBJECTIVES

To examine the impact of epidermal growth factor receptor (EGFR) expression level on the efficacy of monoclonal antibodies against the EGFR.

METHODS

In four human head and neck carcinoma cell lines, epidermal growth factor expression was knocked down by lentiviral RNA interference. Next, the efficacies of cetuximab and panitumumab at concentrations of 4, 40, and 400 μg/ml were measured by real time cell analysis for a 48-h duration. Finally, the different response rates to the drugs were statistically analyzed.

RESULTS

The lentiviral EGFR knockdown efficiency ranged from 18 to 54 % across all of the cell lines. All original cell lines exhibited rather poor or inverse responses with regard to EGFR-AB treatment. In contrast, inhibiting EGFR expression in the same cell lines yielded statistically significant better responses to cetuximab or panitumumab treatment.

CONCLUSIONS

The cell lines used in this study responded poorly to cetuximab and panitumumab. Better anti-EGFR treatment efficacy was related to lower EGFR expression in head and neck cancer cell lines. These findings might influence the selection of patients to receive cetuximab and panitumumab treatment for head and neck cancer.

Correlation of MAGE-A tumor antigens and the efficacy of various chemotherapeutic agents in head and neck carcinoma cells

OBJECTIVES

The present study examined the relationship between MAGE-A tumor antigens and the efficacy of diamindichloridoplatin (DDP), 5-fluorouracil (5-FU), docetaxel, and paclitaxel for in vitro treatment of head and neck cancer.

METHODS

In the present study, five cell lines of human squamous cell carcinomas were treated with DDP (25-400 μM), 5-FU (0.75-12 mM), docetaxel (1.56-25 nM), and paclitaxel (1.56-25 nM) for a period of 24 or 48 h. The efficacy of the agents was observed dynamically using real-time cell analysis. Subsequently, the expression levels of MAGE-A1, MAGE-A5, MAGE-A8, MAGE-A9, MAGE-A11, and MAGE-A12 were determined by quantitative real-time polymerase chain reaction. Chemosensitivity and MAGE-A-expression were correlated by linear regression.

RESULTS

The tumor cell lines showed a highly differentiated response to the chemotherapeutic agents. Expression of MAGE-A11 was significantly associated with a poorer response to treatment with DDP, 5-FU, docetaxel, and paclitaxel. Two cell lines, one of which was MAGE-A11-positive, showed a significant and concentration-dependent cisplatin-induced growth spurt during the first 24 h after treatment. MAGE-A5 was connected to a positive effect on treatment with paclitaxel within the first 24 h after application. In association with docetaxel treatment, MAGE-A8 was connected to a poorer susceptibility.

CONCLUSIONS

The results describe, for the first time, a correlation between these MAGE-A tumor antigens and the susceptibility of head and neck cancer cells to DDP, 5-FU, docetaxel, and paclitaxel.

CLINICAL RELEVANCE

These findings could affect the antineoplastic treatment of patients with MAGE-A11-positive tumors.

Efficacy of cetuximab and panitumumab in oral squamous cell carcinoma cell lines: prognostic value of MAGE-A subgroups for treatment success

BACKGROUND

Over-expression of epidermal growth factor receptor (EGFR) has been observed in a variety of epithelial tumours. The selective inhibition of the associated signalling pathway using monoclonal antibodies appears to be a promising therapeutic target. Individual differences in response rates, particularly against highly selective chemotherapeutic agents, underline the need for further research of the molecular basis of this process. Previously described resistance mechanisms are not able to explain all refractory responses. Several subgroups of the melanoma-associated antigens (MAGE) tumour antigens were described in connection with regulatory functions relating to the cell cycle and chemosensitivity.

METHODS

In the present study, five cell lines of human squamous cell carcinomas were treated with cetuximab and panitumumab (0.01-100 μg/ml) over a period of 24 or 48 h. The efficacy of the agents used was measured dynamically using real-time cell analysis (RTCA). Subsequently, the expression levels of MAGE-A1, -A5, -A8, -A9, -A11 and -A12 were determined by RT-qPCR. A correlation between chemosensitivity and MAGE-A expression was investigated.

RESULTS

The tumour cell lines exhibited a very low overall response to the chemotherapy drugs. Only one cell line showed a cytostatic effect after treatment with cetuximab and panitumumab. This effect, however, was significant only for panitumumab. The expression of MAGE-A12 was significantly associated with greater efficacy of panitumumab. The expression of MAGE-A5 and -A8 was associated with poorer response rates after panitumumab treatment. Due to an insignificant effect of cetuximab on the number of viable cells, no correlation with the MAGE-A levels was observed.

CONCLUSION

For the first time, these results show a correlation between the efficacies of EGFR inhibitors and various MAGE-A subgroups in the treatment of HNSCC. Determining the MAGE-A status could help to improve the success of anti-tumour drug therapy. In addition, evaluating MAGE-A levels might be an important tool in the development of patient-specific treatment protocols.