Radiogenomic markers enable risk stratification and inference of mutational pathway states in head and neck cancer

PURPOSE

Head and neck squamous cell carcinomas (HNSCCs) are a molecularly, histologically, and clinically heterogeneous set of tumors originating from the mucosal epithelium of the oral cavity, pharynx, and larynx. This heterogeneous nature of HNSCC is one of the main contributing factors to the lack of prognostic markers for personalized treatment. The aim of this study was to develop and identify multi-omics markers capable of improved risk stratification in this highly heterogeneous patient population.

METHODS

In this retrospective study, we approached this issue by establishing radiogenomics markers to identify high-risk individuals in a cohort of 127 HNSCC patients. Hybrid in vivo imaging and whole-exome sequencing were employed to identify quantitative imaging markers as well as genetic markers on pathway-level prognostic in HNSCC. We investigated the deductibility of the prognostic genetic markers using anatomical and metabolic imaging using positron emission tomography combined with computed tomography. Moreover, we used statistical and machine learning modeling to investigate whether a multi-omics approach can be used to derive prognostic markers for HNSCC.

RESULTS

Radiogenomic analysis revealed a significant influence of genetic pathway alterations on imaging markers. A highly prognostic radiogenomic marker based on cellular senescence was identified. Furthermore, the radiogenomic biomarkers designed in this study vastly outperformed the prognostic value of markers derived from genetics and imaging alone.

CONCLUSION

Using the identified markers, a clinically meaningful stratification of patients is possible, guiding the identification of high-risk patients and potentially aiding in the development of effective targeted therapies.

HS-173, a selective PI3K inhibitor, induces cell death in head and neck squamous cell carcinoma cell lines

BACKGROUND

The selective PI3K (Phosphatidylinositol 3-kinase) inhibitor HS-173 has anticancer activity in non-small cell lung cancer and pancreatic cancer cells. Of all head and neck squamous cell carcinomas (HNSCC) 20% harbor specific mutations in the genome. The aim of this study was to investigate the effect of HS-173 on HNSCC cell lines.

METHODS

The cell lines SCC25, CAL27 and FaDu were incubated with HS-173. Its antiproliferative effect was determined using the CCK‑8 cell proliferation assay. Combined incubation with cisplatin was performed and combination index analysis was conducted. To investigate its effect on radiotherapy, cells were irradiated with 2, 4, 6 and 8 Gy, respectively. Synergistic effects of radiation and HS-173 were measured by proliferation assays and clonogenic survival.

RESULTS

The use of HS-173 induced significant reduction of cell proliferation across all cell lines. Most interestingly, it showed a synergistic effect with cisplatin treatment. Clonogenic survival revealed a radiosensitizing effect in CAL27 and FaDu cells. The HS-173 caused significant induction of apoptosis in SCC25 and FaDu cells.

CONCLUSION

The selective PI3K inhibitor HS-173 is a potent chemosensitizing and also radiosensitizing drug in treatment of HNSCC cell lines and could be an effective treatment in PI3K-mutated HNSCC.

Expression of inhibitors of apoptosis proteins in salivary gland adenoid cystic carcinoma: XIAP is an independent marker of impaired cause-specific survival

Objectives

Inhibitors of apoptosis proteins are crucial to carcinogenesis since their expression results in evasion of apoptosis. Overexpression of inhibitors of apoptosis has repeatedly been associated with resistance to treatment and poor prognosis in various cancers. The role of inhibitors of apoptosis in adenoid cystic carcinoma of the salivary gland is still unclear. The aim of this study was to investigate the expression of inhibitors of apoptosis and their potential prognostic value in adenoid cystic carcinoma.

Design, setting and participants

Forty‐nine patients, diagnosed with adenoid cystic carcinoma of the salivary gland between 1996 and 2016, were retrospectively included in this study. The expression of cIAP1, cIAP2, XIAP, Birc6, Livin and Survivin was assessed using immunohistochemistry, and their association of survival and prognosis was evaluated during a median follow‐up of 6.4 years.

Main outcome measure

Cause‐specific survival and recurrence‐free survival rates.

Results

XIAP, cIAP2, Livin and nuclear Survivin showed high expression levels in adenoid cystic carcinoma in most patients. There was no significant association of cIAP1, cIAP2, Livin, Birc6 and Survivin with outcome. However, high XIAP expression was associated with worse cause‐specific survival and worse response to radiotherapy and proved to be an independent marker in multivariable analysis.

Conclusion

Our data indicate that high expression of XIAP may be used as a prognosticator for poor survival and poor response to radiotherapy in adenoid cystic carcinoma patients.

Cross-sectional study on the occurrence of Frey's syndrome following superficial parotidectomy or extracapsular dissection

BACKGROUND

Most studies that examine postoperative outcomes after parotidectomy in patients with benign parotid gland tumors are based on retrospective chart reviews. Data about long-term results in patients with parotid gland surgery with patient contact are still sparsely published.

METHODS

During the period of 1960-2005, a total of 127 patients underwent either extracapsular dissection (ECD) or superficial parotidectomy (SP) and were available for interview. Patients were questioned about their postoperative outcome after parotid gland surgery.

RESULTS

The mean follow-up was 21.5 years. A total of 42 and 85 patients underwent ECD and SP, respectively. No significant differences were observed in the rates of permanent facial paralysis (SP 1.2% vs. ECD 7.1%; p = 0.1053) or recurrence (SP 4.7% vs. ECD 11.9%; p = 0.1557), and Frey's syndrome was diagnosed only after SP (10.6% vs. 0% after ECD, p = 0.0293). Frey's syndrome was detected more often compared to retrospective chart analysis.

CONCLUSION

We conclude that Frey's syndrome is underdiagnosed after SP without standardized follow-up examinations. Long-term follow-up should be applied to detect and treat gustatory sweating.

Impact of pretherapeutic neutrophil-to-lymphocyte ratio, serum albumin, body-mass index, and advanced lung cancer inflammation index on clinical outcome in sinonasal squamous cell carcinoma

BACKGROUND

Squamous cell carcinoma of the nasal cavity and paranasal sinuses is a rare and aggressive cancer entity with poor survival rates. Data on this group of head and neck tumors are scarce. Inflammation and cachexia-based markers and their impact on clinical outcome have been studied in several cancer groups. The aim of this study was to evaluate their prognostic potential in sinonasal squamous cell carcinoma.

PATIENTS AND METHODS

This retrospective analysis included all patients treated for sinonasal squamous cell carcinoma at a tertiary referral center between 2002 and 2015. Patients were divided into groups with low and high pretherapeutic values based on the values of serum albumin (ALB, median 41.6 g/l), neutrophil-to-lymphocyte ratio (NLR, median 3.5), body-mass index (BMI, median 24.7), or advanced lung cancer inflammation index (ALI, median 29.5). Main outcome measures were overall survival (OS) and disease-free survival (DFS). Statistical analysis included calculation of survival differences using log-rank tests, hazard ratios (HR), and respective 95% confidence intervals (CI).

RESULTS

41 patients were included. Low ALB values did not influence OS (median OS not reached in both groups; p = 0.59, HR = 0.75, CI = 0.3-2.1) or DFS (median DFS 0.9 years vs 2.2 years; p = 0.6, HR = 0.8, CI = 0.4-1.8). High NLR was significantly associated with worse OS rates (median OS not reached vs 1.7 years, p = 0.02, HR = 3.4, CI = 1.0-108) but with no influence on DFS (median DFS 3.1 years vs 0.8 years; p = 0.15, HR = 1.8, CI = 0.8-4.2). Similar results were observed for patients with low ALI (median OS 1.7 years vs not reached; p = 0.03, HR = 0.3, CI = 0.1-0.9 and median DFS 0.8 years vs 2.2 years; p = 0.58, HR = 0.8, CI = 0.3-1.8). BMI was the strongest prognosticator in our study. Low pretherapeutic BMI was linked to significantly worse OS (median OS 1.4 years vs not reached; p = 0.003, HR = 0.2, CI = 0.0-0.6) and DFS (median DFS 0.8 years vs not reached; p = 0.02, HR = 0.4, CI = 0.2-0.8). In multivariate analysis BMI was revealed as an independent marker for OS (p = 0.015). No marker reached the level of significance in regard to DFS in multivariate analysis.

CONCLUSION

Pretherapeutic BMI had a superior prognostic value in patients with sinonasal squamous cell carcinoma in comparison with other tested variables. BMI may be a simple tool for estimating clinical outcome in SNSCC. However, larger studies are necessary to validate our results.

Evaluation of the cancer stem cell marker DCLK1 in patients with lymph node metastases of head and neck cancer

BACKGROUND

Lymph node metastases are frequently detected in head and neck squamous cell carcinoma (HNSCC) patients. Little is known about biomarkers expressed in lymph node metastases or their influence on clinical outcome. Doublecortin-like kinase 1 (DCLK1) is one marker that might be associated with outcome, owing to its correlation with stem cell-like characteristics.

METHODS

We assessed the expression of DCLK1 in 74 postoperatively irradiated patients in histologically confirmed HNSCC lymph node metastases. Statistical analysis of the association with DCLK1 on clinical outcomes was performed.

RESULTS

DCLK1 was expressed in 63.5% of our patient cohort. DCLK1(+) HNSCC patients, compared with those without DCLK1 expression, showed a significantly poorer time to recurrence. Moreover, we observed a significantly poorer time to recurrence in HPV(-) HNSCC patients, and significantly shorter overall and disease-free survival rates in HPV(-) oropharyngeal cancer patients, compared with HPV(+) patients with these cancers. HPV(+) patients showed no significant differences in survival time according to DCLK1 expression. However, recurrent disease occurred in only DCLK1(+) patients. Mulitivariate analysis showed that DCLK1 expression in lymph node metastases is an independent marker for recurrence.

CONCLUSION

DCLK1 expression might be associated with poorer clinical outcomes in HNSCC patients, specifically in HPV(-) move patients. However, larger studies are required to verify our results.

Impact of anatomic origin of primary squamous cell carcinomas of the nasal cavity and ethmoidal sinus on clinical outcome

PURPOSE

Since squamous cell carcinomas (SCCs) of the nasoethmoidal complex are rare and aggressive malignancies, the purpose of this study was to evaluate whether anatomic subsites of SCCs of the nasal cavity and ethmoid sinuses affect clinical outcome.

METHODS

We retrospectively analyzed data from 47 patients with primary SCCs of the nasal cavity and ethmoid sinuses who were treated at the Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, between 1993 and 2018. The impact of anatomic subsites of nasoethmoidal SCCs was evaluated with respect to tumor and nodal classification, disease-free survival (DFS) and disease-specific survival (DSS).

RESULTS

Of the 47 cases, 17 SCCs (36.2%) originated from lateral nasal wall followed by 13 (27.7%) tumors of the edge of naris to mucocutaneous junction, 11 (23.4%) SCCs of the nasal septum, 3 tumors of the nasal floor (6.4%) and 3 SCCs of the ethmoid sinuses (6.4%), respectively. SCCs of the nasal septum were associated with significantly higher rates of neck node metastasis (p = 0.007), which represented a significantly worse prognostic factor for DSS (HR 7.87; p < 0.001). Moreover, advanced tumor stage (HR 5.38; p = 0.014) and tumor origin of nasal septum (HR 4.05; p = 0.025) were also significantly worse prognostic factors for DSS. Fourteen patients (29.8%) developed recurrent disease, including eight local (17.0%), five regional (10.6%) and one distant (2.1%) recurrence. Elective neck dissection (ND) was associated with lower (0 vs. 20.0%) but not significantly different regional and distant DFS (p = 0.075).

CONCLUSION

Anatomic origin of nasal SCC has significant impact on clinical outcome. SCCs of the nasal septum were associated with higher rates of positive neck nodes and worse outcome.

PD-1 and PD-L1 expression in HNSCC primary cancer and related lymph node metastasis - impact on clinical outcome

AIMS

Expression profiles and clinical impact of programmed cell death ligand 1 (PD-L1) and programmed cell death 1 (PD-1) expressing tumour infiltrating lymphocytes (TILs) in head and neck squamous cell carcinoma (HNSCC) are not elucidated fully. This study evaluates expression patterns in primary HNSCC and related lymph node metastasis and the impact on patients' clinical outcome.

METHODS AND RESULTS

Immunohistochemical staining patterns of PD-L1 and PD-1 were evaluated in 129 specimens of primary HNSCC and 77 lymph node metastases. Results were correlated with patients' clinical data. PD-L1 expression was observed in 36% of primary carcinoma and 33% of lymph node metastasis, and correlates significantly with decreased overall survival (OS) (P = 0.01) and disease-free survival (DFS) (P = 0.001) in oral cavity squamous cell carcinoma patients. PD-L1 expression was associated with presence of lymph node metastasis (P = 0.0223). Infiltration of PD-1-expressing lymphocytes correlates significantly with favourable OS (P = 0.001) and DFS (P = 0.001) in oropharyngeal cancer and hypopharyngeal cancer patients OS (P = 0.007) and DFS (P = 0.001). Presence of PD-1 TILs also correlates significantly with better OS (P = 0.005) and DFS (P = 0) in the human papilloma virus (HPV)-negative cohort. Cox regression multivariate analysis revealed PD-1 TIL expression as an independent prognostic marker for OS (P = 0.004) and DFS (P = 0.001) and T stage was validated as negative prognostic marker for OS (P = 0.011). PD-1-expressing lymphocytes (P = 0.0412) and PD-L1 expression (P = 0.0022) patterns correlate significantly in primary cancers and matched lymph node metastases.

CONCLUSIONS

Our results characterise the expression profiles of PD-1 axis proteins in HNSCC which might serve as possible clinical prognostic markers.

Low SOX2 expression marks a distinct subset of adenoid cystic carcinoma of the head and neck and is associated with an advanced tumor stage

Introduction

The transcription factor SOX2 has been identified as a lineage survival oncogene in squamous cell carcinoma and copy number gain is a common event in several human malignancies including head and neck cancer. However, the regulation and function of SOX2 during carcinogenesis as well as its prognostic value appears to be highly context dependent. As an example, high SOX2 expression in lung squamous cell carcinoma (SCC) is related to a favorable prognosis, while it is associated with poor outcome in lung adenocarcinoma. More recently, higher SOX2 levels and improved survival was also reported for head and neck SCC (HNSCC), and silencing of SOX2 expression in HNSCC cell lines revealed a mesenchymal-like phenotype with prominent vimentin expression. So far, SOX2 expression and its clinical relevance for other head and neck cancers, such as adenoid cystic carcinoma (HNACC) have not been sufficiently investigated.

Material and methods

SOX2, vimentin and E-cadherin expression was assessed by immunohistochemical staining on serial sections from formalin fixed and paraffin embedded tissue samples of a patient cohort (n = 45) with primary ACC and correlated with patient and tumor characteristics as well as survival.

Results

High SOX2 expression was found in 14 (31%) primary tumor specimens and was significantly correlated with a N0 lymph node status (p = 0.04), while low SOX2 expression was correlated with a solid growth pattern (p = 0.031). Of the 45 patients, 27 tumor samples resembled an EMT-like phenotype, as assessed by high vimentin and low E-cadherin levels. However, in HNACC SOX2 levels were neither correlated with vimentin nor with E-cadherin expression, further supporting a context dependent regulation and function of SOX2 in distinct tumor entities.

Conclusion

The absence of SOX2 was predominantly found in solid HNACC, which are characterized by a more aggressive phenotype in ACC. However, the underlying molecular mechanisms of SOX2 regulation and function in distinct HNACC subgroups remain to be fully elucidated.

6-shogaol induces apoptosis and enhances radiosensitivity in head and neck squamous cell carcinoma cell lines

Ginger (Zingiber officinale Roscoe) is used for a wide array of conditions in traditional medicine in Asia, but little is known about the effect on head and neck cancer. In this study, the effect of two major pharmacologically active compounds of ginger, 6-gingerol and 6-shogaol, were studied on head and neck cancer cell lines. Furthermore, experiments in combination with established treatment methods for head and neck cancer were performed. Proliferation assays showed a dose-dependent reduction of cell viability. Flow cytometry analysis revealed the induction of apoptosis. Western blot analysis indicated that the antiapoptotic protein survivin was suppressed after treatment. Although a combination of 6-shogaol with cisplatin exhibited no synergistic effect, the combination with irradiation showed a synergistic reduction of clonogenic survival. In conclusion, ginger compounds have many noteworthy effects on head and neck cancer cell lines. In particular, the enhancement of radiosensitivity is remarkable.

Effect of thymoquinone on head and neck squamous cell carcinoma cells in vitro: Synergism with radiation

Thymoquinone (TQ) is the main bioactive constituent present in black seed oil (Nigella sativa); it has shown anti-inflammatory and anti-neoplastic effects in various cancer cell types. The aim of the present study was to investigate the effects of TQ on head and neck squamous cell carcinoma (HNSCC) cell lines, on its own and in combination with radiation and cisplatin, respectively. The SCC25 and CAL27 HNSCC cell lines were treated with TQ alone and in combination with cisplatin or radiation, respectively. Proliferation assays and clonogenic assays were performed. Apoptosis was detected by flow cytometry. TQ exhibited dose-dependent cytotoxicity via apoptosis in the investigated cell lines. In combination with cisplatin, TQ resulted in no significant increase in cytotoxicity. Combined with radiation, TQ significantly reduced clonogenic survival compared with each treatment method alone. TQ is a promising agent in the treatment of head and neck cancer due to its anti-proliferative and radiosensitizing properties. However, the combination of TQ with cisplatin showed no therapeutic benefit in vitro.

AZD5582, an IAP antagonist that leads to apoptosis in head and neck squamous cell carcinoma cell lines and is eligible for combination with irradiation

CONCLUSION

On the one hand, AZD5582, an inhibitor of inhibitor of apoptosis family proteins (IAP), leads to cellular growth arrest and induction of apoptosis in head and neck squamous cell carcinoma (HNSCC) cell lines. On the other hand, it is a viable candidate for combination therapy with irradiation.

OBJECTIVES

The aim and purpose of this study was to evaluate the effects of AZD5582 on HNSCC cell lines.

METHODS

HNSCC cell lines SCC25, Cal27, and FaDu were used for all cell culture experiments. Proliferation assays were used to assess a potential inhibitory effect of AZD5582 and a combination therapy of the IAP inhibitor and irradiation. Colony forming assays were used to determine long-term effects of a combined treatment. Apoptosis was measured via flow cytometry and wound-healing assays were performed.

RESULTS

All three cell lines showed a dose-dependent cytotoxic effect after treatment with AZD5582. It was possible to observe a synergistic and additive effect after short-term treatment of AZD5582 and irradiation in Ca27 and FaDu cells, respectively. All test cell lines showed a significant inhibition of colony formation after combined treatment. Treatment of AZD5582 resulted in apoptosis in SCC25, Cal27, and FaDu cells.

Effect of the histone deacetylase inhibitor resminostat on head and neck squamous cell carcinoma cell lines

BACKGROUND

Carcinogenesis is determined by various epigenetic events, such as histone deacetylation. The purpose of this study was to investigate the effect of the new histone deacetylase inhibitor resminostat on head and neck squamous cell carcinoma (HNSCC) cell lines.

METHODS

The cytotoxicity of resminostat and cisplatin on HNSCC cell lines SCC25, CAL27, and FaDu was determined using CCK-8 cell proliferation assay and combination index analysis. Cells were irradiated with 2 to 8 Gray. Apoptosis was measured using flow cytometry and expression of Mcl-1, p-AKT, and survivin was investigated.

RESULTS

Treatment with resminostat showed a decrease of cell proliferation of HNSCC cell lines. In addition, a synergistic effect with cisplatin as well as with radiation treatment could be observed. Induction of cell death and dose-dependent downregulation of survivin was evident in all cell lines.

CONCLUSION

Resminostat is a promising treatment of HNSCC because of its antiproliferative, chemosensitizing, and radiosensitizing effects. © 2017 Wiley Periodicals, Inc. Head Neck 39: 900-907, 2017.

ELMO3 predicts poor outcome in T1 laryngeal cancer

OBJECTIVES

Despite the excellent overall survival of 92%-97% in early glottic cancer, recurrence rates of 13%-20% have not improved in the last decades. The engulfment and cell motility protein 3 (ELMO3) have been described as prognostic marker in patients with lung cancer. The aim of this study was to investigate the expression of ELMO3 in early laryngeal cancer patients treated with TLM and to evaluate its prognostic significance on clinical outcome.

DESIGN, SETTING AND PARTICIPANT

Forty-eight patients with glottic carcinoma (T1N0M0) that underwent primary treatment with TLM between 1994 and 2012 were analysed. ELMO3 expression of the tumour was assessed using immunohistochemistry and correlated with clinical data.

MAIN OUTCOME MEASURE

Overall survival, disease-specific survival (DSS) and disease-free survival (DFS) rates RESULTS: Positive ELMO3 expression was found in 23% of the patients and was correlated with poor DSS and DFS (P<.05).

CONCLUSION

This is the first study to show a prognostic effect of positive ELMO3 expression in early glottic carcinoma patients.

ELMO3 expression indicates a poor prognosis in head and neck squamous cell carcinoma - a short report

PURPOSE

Previously, the engulfment and cell motility 3 (ELMO3) protein has been reported to be involved in cell migration and cytoskeletal remodeling. As of yet, nothing is known about the role of ELMO3 in head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to asses ELMO3 expression in postoperatively irradiated HNSCC patients and to evaluate a possible correlation between this expression and patient survival.

METHODS

125 postoperatively irradiated HNSCC patients were included in this study. ELMO3 expression was assessed using immunohistochemistry (IHC). The expression of ELMO3 in the respective HNSCC tumor tissues and its lymph node metastases was correlated with patient survival using Kaplan-Meier curve analyses.

RESULTS

Through IHC, ELMO3 expression was detected in 71.2% of the HNSCC cases tested. We found significantly increased overall and disease-free survival rates and decreased recurrence rates in patients with no detectable ELMO3 expression. In reverse, we found that ELMO3 expression served as an independent marker for a decreased overall and disease-free survival.

CONCLUSION

Our data indicate that in the surgically treated and postoperatively irradiated patients tested, ELMO3 expression serves as a predictive marker for reduced survival.

Impact of Sonic Hedgehog Pathway Expression on Outcome in HPV Negative Head and Neck Carcinoma Patients after Surgery and Adjuvant Radiotherapy

INTRODUCTION

HPV positive patients suffering from head and neck cancer benefit from intensified radiotherapy when applied as a primary as well as an adjuvant treatment strategy. However, HPV negative patients treated with surgery and adjuvant radiotherapy lack validated prognostic biomarkers. It is therefore important to define prognostic biomarkers in this particular patient population. Especially, ´high-risk groups´ need to be defined in order to adapt treatment protocols. Since dysregulation of the sonic hedgehog pathway plays an important role in carcinogenesis, we aimed to assess whether members of the sonic hedgehog-signaling pathway may act as prognostic factors in patients with HPV negative head and neck squamous cell carcinoma.

MATERIALS AND METHODS

In this prospective study, pretreatment tumor biopsies of patients with head and neck squamous cell carcinoma were taken during panendoscopy (2005 to 2008). All patients were treated with surgery and postoperative radiotherapy. After assessment of HPV and p16 status, protein expression profiles of the Sonic hedgehog-signaling pathway were determined by immunohistochemistry and tissue microarray analyses in 36 HPV negative tumor biopsies. Expression profiles of Sonic hedgehog, Indian hedgehog, Patched, Smoothened, Gli-1, Gli-2 and Gli-3 were correlated with patients´ clinical data, local-control rate, disease-free as well as overall survival. Data from The Cancer Genome Atlas databank were used for external validation of our results.

RESULTS

Gli-1 (p = 0.04) and Gli-2 (p = 0.02) overexpression was significantly linked to improved overall survival of HPV negative patients. Gli-2 (p = 0.04) overexpression correlated significantly with prolonged disease-free survival. Cox-multivariate analysis showed that overexpression of Gli-2 correlated independently (HR 0.40, 95% CI 0.16-0.95, p = 0.03) with increased overall survival.

DISCUSSION

Gli-1 and Gli-2 overexpression represents a substantial prognostic factor for overall and disease-free survival in patients with locally advanced HPV negative head and neck cancer undergoing surgery and postoperative radiotherapy.

Effects of neratinib and combination with irradiation and chemotherapy in head and neck cancer cells

OBJECTIVE

Prognosis of patients with head and neck squamous cell carcinoma (HNSCC) is still poor. Novel therapeutic approaches are of great interest to improve the effects of radiochemotherapy. We evaluated the effects of tyrosine kinase inhibitor neratinib on HNSCC cell lines CAL27, SCC25 and FaDu as a single agent and in combination with irradiation and chemotherapy.

METHODS

Effects of neratinib were evaluated in HNSCC cell lines CAL27, SCC25 and FaDu. Effect on cell viability of neratinib and combination with cisplatin and irradiation was measured using CCK-8 assays and clonogenic assays. Western blot analysis was performed to distinguish the effect on epithelial growth factor receptor and HER2 expression. Apoptosis was evaluated by flow cytometry analysis.

RESULTS

Growth inhibition was achieved in all cell lines, whereas combination of cisplatin and neratinib showed greater inhibition than each agent alone. Apoptosis was induced in all cell lines. Combination of neratinib with irradiation or cisplatin showed significantly increased apoptosis. In clonogenic assays, significant growth inhibition was observed in all investigated cell lines.

CONCLUSION

Neratinib, as a single agent or in combination with chemo-irradiation, may be a promising treatment option for patients with head and neck cancer.

Overexpression of DCLK1 is predictive for recurrent disease in major salivary gland malignancies

Salivary gland carcinomas are a rare malignancy. Therefore, little is known about biomarkers and cancer stem cells in salivary gland malignancies. Double cortin-like kinase 1 (DCLK1) is a promising therapeutic target and cancer stem cell marker, predominantly investigated in pancreatic and colorectal cancer. The purpose of this study was to investigate the expression of DCLK1 in major and minor salivary gland carcinomas and its influence on survival. We examined a total of 80 patients with major or minor salivary gland cancer in this retrospective study. Immunohistochemistry with anti-DCLK1 antibody was applied to assess the expression of DCLK1. Moreover, we evaluated the impact of DCLK1 on overall and disease-free survival. DCLK1 expression could be detected in 66.3 % of all examined cases. Overexpression of DCLK1 was associated with reduced overall and disease-free survival in patients with major salivary gland cancer. Disease-free survival reached statistical significance (p = 0.0107). However, expression of DCLK1 had no influence on survival in patients with minor salivary gland cancer. Since treatment of recurrent disease in oncologic patients is utterly challenging, DCLK1 may be a promising prognostic biomarker that helps to identify patients with a high risk for recurrence of major salivary gland carcinoma.

Evaluation of Polo-like kinase 1 as a potential therapeutic target in Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive malignancy of the skin. Treatment options for MCC include surgery, radiotherapy, and chemotherapy. The purpose of this study was to assess the expression of Polo-like kinase 1 (PLK1) in MCC and the role of the inhibitor, BI2536, as a potential therapeutic option in MCC.

METHODS

PLK1 expression was assessed in tissue samples from 28 patients with MCC and 5 healthy skin samples via immunohistochemistry and furthermore in the 2 MCC cell lines, MCC13 and MCC26, via immunoblotting. The impact of increasing doses of BI2536 alone and in combination with cisplatin or irradiation on cell viability was measured using the CCK-8 assay. Colony forming assays were performed to evaluate long-term effects of combination treatments. Additionally, the induction of apoptotic cell death was measured via flow cytometry.

RESULTS

PLK1 is moderately to strongly expressed in 75% of the patients with MCC. The PLK1 inhibitor, BI2536, demonstrated marked inhibition of cell proliferation with IC50 in the low nM range (from 10.07-12.39 nM). Furthermore, BI2536 induces apoptosis in MCC cell lines and acts synergistically in combination with irradiation and cisplatin.

CONCLUSION

Because of the marked upregulation of PLK1 in MCC tumor samples and potent inhibition of cell proliferation using a specific clinically available inhibitor, targeting of PLK1 qualifies as a potential novel therapeutic strategy in MCC. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1918-E1925, 2016.

Evaluation of spheroid head and neck squamous cell carcinoma cell models in comparison to monolayer cultures

Two-dimensional (2D) monolayer cell culture models are the most common method used to investigate tumor cells in vitro. In the few last decades, a multicellular spheroid model has gained attention due to its adjacency to tumors in vivo. The aim of the present study was to investigate immunohistochemical differences between these two cell culture systems. The FaDu, CAL27 and SCC25 head and neck squamous cell carcinoma (HNSCC) cell lines were seeded out in monolayer and multicellular spheroids. The FaDu and SCC25 cells were treated with increasing doses of cisplatin and irradiation. CAL27 cells were not used in theproliferation experiments, since the spheroids of CAL27 cells were not able to process the reagent in CCK-8 assays. Furthermore, they were stained to present alterations of the following antigens: Ki-67, vascular endothelial growth factor receptor, epithelial growth factor and survivin. Differences in growth rates and expression patterns were detected in certain HNSCC cell lines. The proliferation rates showed a significant divergence of cells grown in the three-dimensional model compared with cells grown in the 2D model. Overall, multicellular spheroids are a promising method to reproduce the immunohistochemical aspects and characteristics of tumor cells, and may show different response rates to therapeutic options.

The prognostic significance of β-catenin, cyclin D1 and PIN1 in minor salivary gland carcinoma: β-catenin predicts overall survival

Minor salivary gland carcinoma is a rare and heterogeneous type of cancer. Molecular prognostic and predictive markers are sparse. The aim of this study was to identify new prognostic and predictive markers in minor salivary gland carcinoma. 50 tissue samples of carcinomas of the minor salivary glands (adenoid cystic carcinoma n = 23, mucoepidermoid carcinoma n = 12, adenocarcinoma n = 10, carcinoma ex pleomorphic adenoma n = 2, salivary duct carcinoma n = 1, clear cell carcinoma n = 1, basal cell carcinoma n = 1) were immunohistochemically stained for β-catenin, cyclin D1 and PIN1. Expression patterns were analyzed and correlated to clinical outcome of 37 patients with complete clinical data. High expression of membranous β-catenin was linked to significantly better overall survival in patients with adenoid cystic carcinoma (log rank test, χ (2) = 13.3, p = .00397, Bonferroni corrected p = .024). PIN1 and cyclin D1 did not show any significant correlation to patients' clinical outcome. Expression of β-catenin in adenoid cystic carcinoma of the minor salivary glands significantly correlates with better overall survival. Hence, evaluation of β-catenin might serve as a clinical prognostic marker.

Improved survival in HPV/p16-positive oropharyngeal cancer patients treated with postoperative radiotherapy

INTRODUCTION

In the literature, HPV infection and/or p16 positivity have been consistently demonstrated to correlate with improved response rates in oropharyngeal squamous cell carcinoma (OPSCC) patients treated with primary radiotherapy (RT) alone and in combination with chemotherapy. However, the exact role of HPV/p16 positivity in patients treated with postoperative RT is still unclear.

METHODS

We analyzed tumor samples for HPV-DNA and p16 expression and correlated these variables with treatment outcome in a series of 63 consecutively treated oropharyngeal cancer patients (95% stage III/IV). HPV and p16 analysis were performed using validated test systems. Survival was estimated by the Kaplan-Meier method. Cox proportional hazard regression models were applied to compare the risk of death among patients stratified according to risk factors.

RESULTS

Expression of p16 or high-risk HPV-DNA was detected in 60.3% and 39.6% of the tumors, respectively. p16 expression [overall survival (OS) at 2 years: 91%] as well as HPV infection (OS at 2 years: 95%) was associated with improved OS. Mean survival in p16-positive patients was 112 months compared to 64.6 months in case of p16 negativity. All HPV-positive tumors stained positive for p16. In a multivariable analysis, p16 positivity was associated with improved OS and with disease-free survival.

CONCLUSION

p16 expression and HPV infection are strongly associated with the outcome of postoperatively irradiated OPSCC patients. HPV and p16 double-negative OPSCC patients should be regarded as a distinct "very high-risk patient group" that may benefit from intensified or novel treatment combinations.

Correlation of β-catenin, but not PIN1 and cyclin D1, overexpression with disease-free and overall survival in patients with cancer of the parotid gland

BACKGROUND

Malignant tumors of the salivary glands comprise about 3% to 5% of all head and neck carcinomas. The purpose of our study was to find possible predictive and/or prognostic markers for parotid cancer.

METHODS

A total of 46 tissue samples of carcinomas of the parotid gland were immunohistochemically stained for ß-catenin, cyclin D1, and PIN1. The factors were analyzed regarding their prognostic value for disease-free and overall survival.

RESULTS

An overexpression of the cytoplasmatic ß-catenin was linked to a statistically significant worse outcome regarding disease-free (p = .0296) and overall survival (p = .0416). The 5-year overall survival was 83.9% in patients without and 0% in patients presenting with overexpression of cytoplasmatic ß-catenin. Additionally, Union Internationale Contre le Cancer (UICC) stage correlated with overall survival (p = .0306) and disease-free survival (DFS; p = .0473).

CONCLUSION

Multivariate analysis showed that overexpression of cytoplasmatic ß-catenin and the UICC stage are 2 independent prognostic markers for survival in patients with parotid cancer.