Kolja Freier

Recurrent copy number gain of transcription factor SOX2 and corresponding high protein expression in oral squamous cell carcinoma

Gene copy number aberrations are involved in oral squamous cell carcinoma (OSCC) development. To delineate candidate genes inside critical chromosomal regions, array‐CGH was applied to 40 OSCC specimens using a microarray covering the whole human genome with an average resolution of 1 Mb. Gene copy number gains were predominantly found at 1q23 (9 cases), 3q26 (11), 5p15 (13), 7p11 (7), 8q24 (17), 11q13 (15), 14q32 (8), 19p13 (8), 19q12 (7), 19q13 (8), and 20q13 (9), whereas gene copy number losses were detected at 3p21‐3p12 (15), 8p32 (11), 10p12 (8), and 18q21‐q23 (10). Subsequent mRNA expression analyses by quantitative real time polymerase chain reaction found high mRNA expression of candidate genes SOX2 in 3q26.33, FSLT3 in 19p13.3, and CCNE1 in 19q12. Tissue microarray (TMA) analyses in a representative OSCC collection found gene copy number gain for SOX2 in 52% (115/223) and for CCNE1 in 31% (72/233) of the tumors. Immunohistochemical analyses on TMA sections of the corresponding proteins detected high expression of SOX2 in 18.1% (49/271) and of CyclinE1 in 23.3% (64/275) of tumors analyzed. These findings indicate that SOX2 and CCNE1 might be activated via gene copy number gain and participate in oral carcinogenesis. The combination of array‐CGH with TMA analyses allows rapid pinpointing of novel promising candidate genes, which might be used as therapeutic stratification markers or target molecules for therapeutic interference.

Recurrent coamplification of cytoskeleton-associated genes EMS1 and SHANK2 with CCND1 in oral squamous cell carcinoma.

Chromosomal band 11q13 is frequently amplified in oral squamous cell carcinoma (OSCC) and assumed to be critically involved in tumor initiation and progression by proto‐oncogene activation. Though cyclin D1 (CCND1) is supposed to be the most relevant oncogene, several additional putative candidate genes are inside this chromosomal region, for which their actual role in tumorigenesis still needs to be elucidated. To characterize the 11q13 amplicon in detail, 40 OSCCs were analyzed by comparative genomic hybridization to DNA microarrays (matrix‐CGH) containing BAC clones derived from chromosomal band 11q13. This high‐resolution approach revealed a consistent amplicon about 1.7 Mb in size including the CCND1 oncogene. Seven BAC clones covering FGF3, EMS1, and SHANK2 were shown to be frequently coamplified inside the CCND1 amplicon. Subsequent analysis of tissue microarrays by FISH revealed amplification frequencies of 36.8% (88/239) for CCND1, 34.3% (60/175) for FGF3, 37.4% (68/182) for EMS1, and 36.3% (61/168) for SHANK2. Finally, quantitative mRNA expression analysis demonstrated consistent overexpression of CCND1 in all tumors and of EMS1 and SHANK2 in a subset of specimens with 11q13 amplification, but no expression of FGF3 in any of the cases. Our study underlines the critical role of CCND1 in OSCC development and additionally points to the functionally related genes EMS1 and SHANK2, both encoding for cytoskeleton‐associated proteins, which are frequently coamplified with CCND1 and therefore could cooperatively contribute to OSCC pathogenesis.

Diagnostic imaging in the management of craniosynostoses

Craniosynostoses are the most frequent craniofacial malformations. However, with a prevalence of 3–6 cases per 10,000 live births they are amongst the rarely seen diseases and their definite diagnosis thus poses a challenge to the physician. When an abnormal calvarial configuration is detected, a radiological evaluation is necessary to characterize the deformity and to guide the corrective surgical procedure. The demand for clear diagnostic criteria is justified by the severity of the disease and the possible consequences of delayed diagnosis. In addition to the clinical signs (deformation of the head), conventional skull X-rays show typical radiological alterations and are used for basic diagnostics. Diagnostic tests that may be performed to confirm the diagnosis and assess the extent of the problem, include computed tomography (CT), 3D-CT, magnetic resonance imaging (MRI) scans, and ultrasonography. In the present review we will describe the most important clinical and radiological characteristics of craniosynostosis by means of clinical, radiological and operative situs examples.

Amplification of Cyclin L1 is associated with lymph node metastases in head and neck squamous cell carcinoma (HNSCC).

Overrepresentation of chromosomal bands 3q25–q29 has been associated with shortened disease-specific survival in head and neck squamous cell carcinoma (HNSCC). To assess the prevalence of copy number gains (>4 signals per cell) and high-level amplifications (>8 signals per cell) from putative oncogenes in this chromosomal region (CCNL1, SNO, PIK3CA, TP73L), tissue microarray analysis was applied on 280 HNSCCs by fluorescence in situ hybridization. Overall frequency of additional copy numbers was 34.3% for CCNL1, 31.8% for SNO, 39.0% for PIK3CA and 38.3% for TP73L, respectively. In general, gains were more frequently detected in stage IV compared to stage I–III tumours. Performing multivariate logistic regression analysis, a significant association of CCNL1 gains and the presence of lymph node metastases was found, which was independent of anatomical site and T-stage of the primary tumour (P=0.049). Site-specific subgroup analysis further showed that copy number gains of CCNL1 and SNO occurred more frequently in oral carcinomas in advanced clinical stages as compared to N0 oral lesions (CCNL1: P=0.03; SNO: P=0.03). Finally, Kaplan–Meier analysis revealed that high-level amplifications of CCNL1 correlated with shorter overall survival of the patients. Our results indicate that CCNL1 plays a critical role in the loco-regional progression of HNSCC and may serve as an indicator for occult advanced tumour stages.

P16INK4a/Ki-67 co-expression specifically identifies transformed cells in the head and neck region

p16INK4a immunohistochemical overexpression is an overall reliable surrogate marker of human papillomavirus (HPV)‐associated head and neck squamous cell carcinomas (HNSCC). However, cases of ambiguous p16INK4a overexpression are regularly detected in the head and neck: p16INK4a expression can be observed in non‐malignant tissue, such as tonsillar crypt epithelium and a proportion of branchial cleft cysts. Additionally, diverse patterns of p16INK4 expression can complicate interpretation of “p16INK4a‐positivity”. These aspects impede the unrestricted application of p16INK4a as a diagnostic marker in the head and neck. We hypothesized that combined detection of p16INK4a and the proliferation marker Ki‐67 could support clarification of ambiguous p16INK4a expression in the head and neck by specifically indicating p16INK4a‐expressing cells with proliferative activity. p16INK4a/Ki‐67 co‐expression in a combined staining procedure was correlated to distinct p16INK4a expression patterns and HPV status (HPV DNA followed by E6*I oncogene mRNA detection) in 147 HNSCC and 50 non‐malignant head and neck samples. p16INK4a/Ki‐67 co‐expression only occurred in transformed cells of the head and neck. Co‐expression was never detected in non‐transformed cells. Combined p16INK4a/Ki‐67 expression was stringently associated with a diffuse p16INK4a expression pattern. All HPV oncogene‐expressing HNSCC showed p16INK4a/Ki‐67 co‐expression. We demonstrate that p16INK4a/Ki‐67 co‐expression occurs exclusively in transformed cells of the head and neck. Our findings indicate a substantial impact of combined p16INK4a/Ki‐67 expression in the assessment of ambiguous p16INK4a expression in the head and neck by specifically identifying p16INK4a‐expressing cells with proliferative activity. This property will be of considerable significance for head and neck histo‐ and cytopathology.

Lack of evidence of human papillomavirus-induced squamous cell carcinomas of the oral cavity in southern Germany

OBJECTIVES The aim of the present study was to identify HPV-attributable SCC of the oral cavity (OSCC) in a cohort of patients from southern Germany. MATERIALS AND METHODS A sensitive PCR-enzyme immunoassay (EIA) was followed by a more specific in situ hybridization (ISH) to detect high risk human papillomavirus (HPV). An immunohistochemical dual-staining for p16(INK4a) and the proliferation marker Ki-67 was used to assess whether co-expression of p16(INK4a)/Ki-67 is a better surrogate marker for HPV in OSCC than p16(INK4a) alone, based on the hypothesis that combined p16(INK4a) and Ki-67 expression might specifically discriminate oncogene-induced p16(INK4a) expression from cell-cycle arrest-inducing senescence-associated p16(INK4a) expression. RESULTS HPV-DNA by PCR-EIA could be detected in 25.1% (69/275) of the tumors, but ISH was negative in all of them. Diffuse p16(INK4a) overexpression was detected in 11 HPV PCR-positive tumors, but also in 6 HPV PCR-negative tumors. p16(INK4a)-expressing cells in diffusely positive tumors co-expressed Ki-67, irrespective of the HPV status. Neither the sole HPV status nor combined HPV/p16(INK4a) status nor the sole p16(INK4a) status was significantly associated with disease free or overall survival, however a trend towards better overall survival of patients whose tumor expressed p16(INK4a) in a focal pattern (=p16(INK4a)-positive/Ki-67-negative cells) compared to no p16(INK4a) expression (p=0.09) was observed. CONCLUSION Viral DNA can be detected in some tumors by a sensitive PCR, but absence of ISH signals indicates that the HPV-attributable fraction is smaller than estimated from PCR positivity. p16(INK4a)/Ki-67 co-expression is detectable in a fraction of OSCC irrespective of the HPV status.

Cetuximab and radiation for primary and recurrent squamous cell carcinoma of the head and neck (SCCHN) in the elderly and multi-morbid patient: a single-centre experience

BackgroundChemoradiotherapy for head and neck cancer (SCCHN) is challenging in elderly, multi-morbid patients. Radioimmunotherapy (RIT) with cetuximab provides an option to enhance efficacy of radiotherapy without increased toxicity. We present a single-centre experience of RIT these patients.MethodsToxicity and outcome was retrospectively analysed in patients treated with radiotherapy and cetuximab between 2006 and 2009. Treatment response was analysed at first follow-up, outcome was estimated using Kaplan-Meier analyses.Results73 patients with primary/recurrent SCCHN were treated (re-irradiation: 22 patients). CTC grade 3 allergic reactions occurred in 4 patients, grade 3 acneiforme skin reactions leading to discontinuation of cetuximab in 3 patients.Overall response rate was 59,4%, median locoregional and overall progression-free survival (PFS) was 18 and 15 months, overall survival (OS) 18 months.ConclusionRIT is a feasible treatment option for elderly and multi-morbid patients with promising therapeutic activity. Long-term disease control can also be achieved in patients receiving RIT for re-irradiation.

High-LET radiotherapy for adenoid cystic carcinoma of the head and neck: 15 years' experience with raster-scanned carbon ion therapy.

PURPOSE Locoregional control (LC) in malignant salivary gland tumors is dose-dependent, initial results with particle therapy were promising. We report our experience with raster-scanned, intensity-controlled carbon ion therapy (C12) and IMRT in 309 patients with pathologically confirmed adenoid cystic carcinoma (ACC) of the head and neck. PATIENTS AND METHODS Treatment records of patients treated with C12 between 08/1998 and 05/2013 were evaluated regarding tumor stage, treatment, toxicity (CTCAE v3), LC, progression-free survival (PFS) and overall survival (OS). Response assessment was carried out according to RECIST1.1. RESULTS Tumor stages were mostly advanced (T4a/b: 60%, macroscopic disease: 71%), most common sites of origin were the paranasal sinus (37%). At a median follow-up at 33.9 months, LC, PFS, and OS at 3 and 5 year estimates are 83.7%/58.5%, 67.8%/56.1%, and 88.9%/74.6%. LC correlates with T-stage but neither nodal stage, age, relapse state, nor margin status. RECIST did not correlate with LC or survival rates. CONCLUSION IMRT plus C12 boost results in good control and survival rates at moderate toxicity. Margin status did not correlate with LC in T4 tumors, extensive and potentially mutilating surgical procedures may have to be re-evaluated. RECIST assessment did not correlate with either LC or survival rates; potentially more meaningful radiological parameters need to be developed.

Cytogenetic characterization of head and neck squamous cell carcinoma cell lines as model systems for the functional analyses of tumor-associated genes

Head and neck squamous cell carcinoma (HNSCC) is a solid malignant neoplasm exhibiting aggressive phenotypes and high recurrence rates. To improve its clinical management, understanding the molecular basis of HNSCC development is of critical importance. For the investigation of tumor-associated genes, functional analyses in well-characterized tumor cell systems are required. To establish an experimental platform, a set of 20 HNSCC cell lines was screened for genetic imbalances by chromosomal comparative genomic hybridization (cCGH). Frequent DNA copy number gains were detected on 3q26.3-qter, 5p, 7p11-p13, 8q23-qter, 9p11-p13, 9q31-qter, 11q13 and 20q13.1, whereas copy number losses were found on 3p, 4p, 4q32.1-qter, 8p11-p12 and 18q22 in agreement with previous observations on genetic aberrations detected in primary HNSCC specimens. Subsequent mRNA expression analysis of 11q13 candidate genes CCND1 and CTTN revealed that HNSCC cell lines exhibiting a DNA copy number gain on 11q13 had a higher transcript level of CCND1 and CTTN compared with HNSCC cell lines without 11q13 copy number gain (P = 0.014 and P = 0.009, respectively). Furthermore, CCND1 and CTTN amplification as detected by fluorescence in situ hybridization correlated with protein expression as assessed by immunocytochemistry. In summary, the cytogenetic characterization illustrates that this set of HNSCC cell lines is representative for the HNSCC genome and provides tumor model systems for detailed analysis of genes with a possible role in the pathomechanism of head and neck tumors.

Oral health-related quality of life and depression/anxiety in long-term recurrence-free patients after treatment for advanced oral squamous cell cancer

This report focuses on the association between oral health-related quality of life (OHRQoL) and depression/anxiety of a homogeneous group of cancer patients who were recurrence-free for 8 years after treatment for advanced oral squamous cell. Participants were 24 patients (mean age 55 years, 75% men) treated with neoadjuvant concurrent radiochemotherapy followed by surgery with a mean recurrence-free period of 95 months (from 39 to 164 months). The OHRQoL (OHIP) and the anxiety/depression (HADS) were assessed twice (1 year between t1 and t2). OHRQoL was impaired in this group (mean OHIP score 65 units). In cross-lagged correlation analysis, the correlation between OHRQoL to t1 and depression to t2 was significant and greater than the non-significant correlation for depression to t1 and OHRQoL to t2 indicating that OHRQoL predicts depression better than vice versa. However, the difference in the correlation coefficients was not significant (ZPF-test). The same was true for OHRQoL and anxiety. The OHRQoL measured with the OHIP was impaired in comparison to the normal population. In the limitations of the study design and bearing the small sample size in mind, the results give evidence that OHRQoL predicts psychological outcomes, namely depression and anxiety, better than vice versa.