Florian Sommerer

SOCS-3 is frequently methylated in head and neck squamous cell carcinoma and its precursor lesions and causes growth inhibition.

The suppressors of cytokine signaling (SOCS) are inhibitors of cytokine signaling that function via the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. Recently, methylation of SOCS-1 and SOCS-3 has been implicated in the tumorigenesis of liver and lung cancer. This study was performed to elucidate the role of SOCS-1 and SOCS-3 in squamous cell carcinoma of the head and neck (HNSCC) and its precursor lesions. HNSCC of 94 patients and corresponding normal mucosa, lymph node metastases as well as 16 high- and 21 low-grade squamous cell dysplasias were studied by using methylation-specific PCR (MSP) for the SOCS-1 and SOCS-3 promoter after microdissection. The presence of SOCS-3 mRNA transcripts was confirmed by semiquantitative real-time PCR, and the SOCS-3 protein was analysed immunohistochemically. SOCS-3 hypermethylation was found in 85/94 HNSCC (90%) and in 10/16 high-grade and 9/21 low-grade dysplasias (63 and 43%, respectively). SOCS-1 promoter hypermethylation was detected in 10/94 HNSCC samples (11%) and in 2/16 high-grade and 1/21 low-grade dysplasias (13 and 5%, respectively). Lymph node metastases exhibited an identical methylation status as the primary tumors. Methylation of the SOCS-3 promoter correlated with downregulation of SOCS-3 transcripts and protein expression in these tumors and various cell lines. In the cell lines tested, SOCS-3 and SOCS-1 transcripts increased upon treatment with the demethylation compound 5-aza-2-deoxycytidine (5-AZA-DC). Overexpression of wild-type SOCS-3 in carcinoma cells with methylated SOCS-3 resulted in the induction of apoptosis and growth suppression as well as downregulation of STAT3, bcl-2 as well as bcl-xL. Our data suggest that promoter methylation and subsequent transcript downregulation of SOCS-3 transcripts and, to a much lesser extent, SOCS-1 are involved in the multistep carcinogenesis of HNSCC. During its involvement in tumor growth, restoration of SOCS-3 may hold treatment potential for HNSCC.

Mutations of the BRAF gene in squamous cell carcinoma of the head and neck

The RAF/MEK/ERK (MAPK) signal transduction cascade is an important mediator of a number of cellular fates including growth, proliferation and survival. The BRAF gene, one of the human isoforms of RAF, is activated by oncogenic RAS, leading to cooperative effects in cells responding to growth factor signals. This study was performed to elucidate a possible function of BRAF in squamous cell carcinoma of the head and neck (HNSCC). Mutations of BRAF and KRAS2 were evaluated in 89 HNSCC and corresponding normal mucosa by direct DNA sequencing analyses after microdissection. The results obtained were correlated with histopathological variables. Activating BRAF missense mutations were identified in 3/89 HNSCC (3%). KRAS2 mutations were found in five out of 89 (6%) HNSCC examined. There were no mutations of KRAS2 and BRAF in non-neoplastic mucosa. We failed to observe a correlation between BRAF or KRAS2 mutations and histopathological factors. Our data indicate that BRAF gene mutations are relatively rare events in HNSCC. Although uncommon, BRAF mutations may identify a subset of patients with HNSCC sensitive to targeted therapy.

The Impact of Real-Time Elastography Guiding a Systematic Prostate Biopsy to Improve Cancer Detection Rate: A Prospective Study of 353 Patients

PURPOSE We evaluated whether real-time elastography guided biopsy improves prostate cancer detection compared to conventional systematic gray scale ultrasound guidance. MATERIALS AND METHODS A total of 353 consecutive patients suspicious for prostate cancer were prospectively randomized for real-time elastography (178) or gray scale ultrasound (175). Each patient enrolled in the study underwent a 10-core prostate biopsy. Six lateral prostate sectors (base, mid, apex) were scanned for cancer suspicious areas, defined as stiffer blue lesions using real-time elastography and hypoechoic lesions using gray scale ultrasound. Suspicious areas were sampled by a single targeted biopsy and considered representative of a defined prostate sector. If real-time elastography or gray scale ultrasound did not visualize a suspicious area in a sector, the biopsy core was taken systematically. Imaging findings were correlated with histopathological reports. Real-time elastography and gray scale ultrasound cases were compared in terms of cancer detection rate and imaging guidance accuracy. RESULTS Characteristics of patients undergoing real-time elastography and gray scale ultrasound, including age, prostate specific antigen, prostate volume and digital rectal examination, were not significantly different (p>0.05). Prostate cancer was detected in 160 of 353 patients (45.3%). The prostate cancer detection rate was significantly higher in patients who underwent biopsy with the real-time elastography guided approach compared to the gray scale ultrasound guided biopsy at 51.1% (91 of 178) vs 39.4% (69 of 175) (p=0.027). Overall sensitivity and specificity to detect prostate cancer was 60.8% and 68.4% for real-time elastography vs 15% and 92.3% for gray scale ultrasound, respectively. CONCLUSIONS Sensitivity to visualize and detect prostate cancer improved using real-time elastography in addition to gray scale ultrasound during prostate biopsy. Overall sensitivity did not reach levels to omit a systematic biopsy approach.

Mutations of BRAF and KRAS2 in the development of Barrett's adenocarcinoma

Activation of the Raf/MEK/ERK (MAPK) signal transduction cascade by RAS mutations has been found in a variety of human cancers. Mutations of BRAF provide an alternative route for activation of this signalling pathway. To determine the role of mutations in BRAF and KRAS2 in the neoplastic progression of Barretts adenocarcinoma, we analysed both genes for common mutations. After microdissection, DNA of 19 Barretts adenocarcinomas, 56 Barretts intraepithelial neoplasias (n=29 low-grade intraepithelial neoplasia (LGIN) and n=27 high-grade intraepithelial neoplasia (HGIN)), 30 Barretts mucosa without neoplasia and normal squamous, as well as gastric epithelium, were analysed for BRAF and KRAS2 mutation. Activating BRAF mutations were identified in 2/19 Barretts adenocarcinomas (11%) and in 1/27 HGIN (4%). KRAS2 mutations were found in four out of 19 (21%) Barretts adenocarcinomas examined and in three cases of HGIN (11%). In LGIN as well as in normal gastric or oesophageal mucosa, neither BRAF nor KRAS2 mutations were detected. All lesions with KRAS2 mutations had an intact BRAF gene. The status of mismatch-repair proteins was neither related to BRAF nor KRAS2 mutations. These data indicate that RAS or BRAF mutations are detected in about 32% of all Barretts adenocarcinomas. We conclude that the disruption of the Raf/MEK/ERK (MAPK) kinase pathway is a frequent but also early event in the development of Barretts adenocarcinoma.

Comparison of real-time elastography with grey-scale ultrasonography for detection of organ-confined prostate cancer and extra capsular extension: a prospective analysis using whole mount sections after radical prostatectomy

Study Type – Diagnostic (exploratory cohort) Level of Evidence 2b

Multiparametric ultrasound of the prostate: adding contrast enhanced ultrasound to real-time elastography to detect histopathologically confirmed cancer.

PURPOSE We prospectively assessed whether a combined approach of real-time elastography and contrast enhanced ultrasound would improve prostate cancer visualization. MATERIAL AND METHODS Between June 2011 and January 2012, 100 patients with biopsy proven prostate cancer underwent preoperative transrectal multiparametric ultrasound combining real-time elastography and contrast enhanced ultrasound. After initial elastographic screening for suspicious lesions, defined as blue areas with decreased tissue strain, each lesion was allocated to the corresponding prostate sector. The target lesion was defined as the largest cancer suspicious area. Perfusion was monitored after intravenous injection of contrast agent. Target lesions were examined for hypoperfusion, normoperfusion or hyperperfusion. Imaging results were correlated with final pathological evaluation on whole mount slides after radical prostatectomy. RESULTS Of 100 patients 86 were eligible for final analysis. Real-time elastography detected prostate cancer with 49% sensitivity and 73.6% specificity. Histopathology confirmed malignancy in 56 of the 86 target lesions (65.1%). Of these 56 lesions 52 (92.9%) showed suspicious perfusion, including hypoperfusion in 48.2% and hyperperfusion in 48.2%, while only 4 (7.1%) showed normal perfusion patterns (p = 0.001). The multiparametric approach decreased the false-positive value of real-time elastography alone from 34.9% to 10.3% and improved the positive predictive value of cancer detection from 65.1% to 89.7%. CONCLUSIONS Perfusion patterns of prostate cancer suspicious elastographic lesions are heterogeneous. However, the combined approach of real-time elastography and contrast enhanced ultrasound in this pilot study significantly decreased false-positive results and improved the positive predictive value of correctly identifying histopathological cancer.

Intraoperative Frozen Section of the Prostate Decreases Positive Margin Rate While Ensuring Nerve Sparing Procedure During Radical Prostatectomy

PURPOSE We evaluated whether intraoperative frozen section analysis of the prostate surface might provide significant information to ensure nerve sparing and minimize the positive margin rate. MATERIALS AND METHODS In 236 patients treated with radical prostatectomy between June 2011 and September 2012 whole surface frozen section analysis of the removed prostate was done intraoperatively. The apex and base were circumferentially dissected as well as the whole posterolateral tissue corresponding to the neurovascular bundles. Multiple perpendicular sections were cut systematically for frozen section analysis. Pathology results were reported to navigate the procedure. RESULTS Frozen section analysis identified positive surgical margins in 22% of cases, including the neurovascular bundles in 56.9%, apex in 34.5% and base in 8.6%. Of positive frozen section cases 92.3% could be converted to negative status, while 7.7% remained positive. The final positive margin rate in the total cohort was 3%, including a false-negative frozen section rate of 1.6%. In 14.8% of cases the initial nerve sparing plan was changed intraoperatively due to the positive frozen section and the secondary resected specimen detected cancer in 25%. Final pathology results showed Gleason upgrading or up-staging in 40.7% of cases compared to preoperative variables. When comparing patients with positive vs negative frozen sections, preoperative variables did not significantly differ, while postoperatively pathological stage, tumor volume, operative time and final margin status differed significantly. Of patients with exclusively unilateral positive biopsies 13% had a positive surgical margin intraoperatively on the opposite, biopsy negative side. CONCLUSIONS The surface frozen section technique is associated with a low false-negative surgical margin rate. It might allow for safer preservation of functional anatomical structures in misclassified patients or even patients at higher preoperative risk.

Cryopreserved human amniotic membrane for soft tissue repair in rats.

Fresh amniotic membrane has been used in medicine since 1910. The reconstruction of immunologic privileged ocular surfaces with cryopreserved amniotic membrane was introduced in the 1990s. The aim of this study was to analyze the use of cryopreserved human amniotic membrane (HAM) as a surgical patch in immunologic unprivileged anatomic sites. In part I of the investigation, the abdominal wall muscle of 36 rats was covered with mono- and multilayered HAM. After 3, 14, and 28 days, respectively, these grafts were evaluated macro- and microscopically. Multilayer samples displayed slower degradation and less inflammation compared with monolayer coverage. In part II of the study, abdominal wall closure with multilayer HAM and with polypropylene mesh was conducted in 20 rats. All rats showed sufficient closure after 21 days, but significantly lower intraabdominal adhesion formation was observed in the HAM rats. The results of this study might pave the way for the use of cryopreserved HAM as graft material in reconstructive surgery.

Impact of Real-Time Elastography on Magnetic Resonance Imaging/Ultrasound Fusion Guided Biopsy in Patients with Prior Negative Prostate Biopsies

PURPOSE The fusion of multiparametric resonance imaging and ultrasound has been proven capable of detecting prostate cancer in different biopsy settings. The addition of real-time elastography promises to increase the precision of the outcome of targeted biopsies. We investigated whether real-time elastography improves magnetic resonance imaging/transrectal ultrasound fusion targeted biopsy in patients after previous negative biopsies. MATERIALS AND METHODS Prospectively 121 men underwent 3T magnetic resonance imaging. Using magnetic resonance imaging/real-time elastography fusion every suspicious lesion was characterized according to its tissue density and sampled by 2 fusion guided targeted biopsies. Additionally, all patients underwent 12-core systematic biopsy. The detection rate of clinically significant and insignificant cancers was compared between targeted und systematic biopsies. The accuracy to predict high grade prostate cancer was evaluated for with the PI-RADS scoring system and compared to the magnetic resonance imaging/real-time elastography fusion score. RESULTS Overall prostate cancer was detected in 52 patients (43%). Targeted fusion guided biopsy revealed prostate cancer in 32 men (26.4%) and systematic biopsy in 46 (38%). The proportion of clinically significant cancers was higher for targeted biopsy (90.6%) compared to systematic biopsy (73.9%). The detection rate per core was higher for targeted biopsies (14.7%) compared to systematic biopsies (6.5%, p <0.001). The prediction of biopsy result according to magnetic resonance imaging/real-time elastography fusion was better (AUC 0.86) than magnetic resonance imaging alone (AUC 0.79). Sensitivity and specificity for magnetic resonance imaging/real-time elastography fusion was 77.8% and 77.3% vs 74.1% and 62.9% for magnetic resonance imaging. CONCLUSIONS Magnetic resonance imaging/transrectal ultrasound fusion enhances the likelihood of detecting clinically significant cancers in a repeat biopsy setting. Adding real-time elastography to magnetic resonance imaging supports the characterization of cancer suspicious lesions.

Open radical retropubic prostatectomy gives favourable surgical and functional outcomes after transurethral resection of the prostate.

To assess the peri‐ and postoperative outcome of patients treated with open radical retropubic prostatectomy (RRP) for prostate cancer and who had previously undergone transurethral resection of the prostate (TURP).