Johannes Wikner

Prognostic Relevance of Circulating Tumor Cells in Blood and Disseminated Tumor Cells in Bone Marrow of Patients with Squamous Cell Carcinoma of the Oral Cavity

Purpose: Current staging methods for squamous cell carcinomas (SCC) of the oral cavity (OSCC) need to be improved to predict the risk of individual patients. Because hematogenous tumor cell dissemination is a key event in tumor progression, we assessed the prognostic significance of disseminated tumor cells (DTC) in bone marrow and circulating tumor cells (CTC) in peripheral blood from patients with OSCC. Experimental Design: From 110 patients with OSCC, tumors were surgically resected (R0) without neoadjuvant therapy. The CellSearch system was used to enumerate CTCs. Bone marrow was aspirated from the iliac crest, and mononuclear cells (MNC) were enriched by Ficoll density gradient centrifugation. To detect DTCs, MNCs were immunostained with the pan-keratin antibody A45-B/B3. Results were correlated with clinicopathologic parameters and clinical outcome such as recurrence and death during follow-up time (mean 916 days). Results: Ten of 80 patients (12.5%) harbored CTCs in peripheral blood, whereas in 18 of 90 patients (20.0%) DTCs in bone marrow could be detected. Surprisingly, in only 2 patients (1.8%) CTCs and DTCs were detected simultaneously. Significant correlations could be found for CTCs and tumor size (P = 0.04), nodal status and DTCs (P = 0.02), and distant metastasis with CTCs (P = 0.004) and DTCs (P = 0.005). Univariate and multivariate analyses revealed that CTCs and DTCs were significant and independent predictors of recurrence-free survival (P < 0.001). Conclusions: Both DTCs and CTCs are independent prognostic markers in patients with OSCC, predicting relapse with higher sensitivity at various disease stages than routine staging procedures. Bone marrow might be an interesting target organ for future therapeutic interventions. Clin Cancer Res; 20(2); 425–33. ©2013 AACR.

Intraoperative efficiency of fluorescence imaging by Visually Enhanced Lesion Scope (VELscope®) in patients with bisphosphonate related osteonecrosis of the jaw (BRONJ)

OBJECTIVES The purpose of this study was to determine the potential of tissue fluorescence imaging by using Visually Enhanced Lesion Scope (VELscope) for the detection of osteonecrosis of the jaw induced by bisphosphonates (BRONJ). METHODS We investigated 20 patients (11 females and 9 males; mean age 74 years, standard deviation ± 6.4 years), over a period of 18 month with the diagnosis of BRONJ in this prospective cohort study. All patients received doxycycline as a fluorescending marker for osseous structures. VELscope has been used intraoperatively using the loss of fluorescence to detect presence of osteonecrosis. Osseous biopsies were taken to confirm definite histopathological diagnosis of BRONJ in each case. RESULTS Diagnosis of BRONJ was confirmed for every patient. In all patients except one, VELscope was sufficient to differentiate between healthy and necrotic bone by visual fluorescence retention (VFR) and visual fluorescence loss (VFL). 19 cases out of a total of 20 showed no signs of recurrence of BRONJ during follow-up (mean 12 months, range 4-18 months). CONCLUSION VELscope examination is a suitable tool to visualize necrotic areas of the bone in patients with bisphosphonate related osteonecrosis of the jaw. Loss of fluorescence in necrotic bone areas is useful intraoperatively as a tool for fluorescence-guided bone resection with relevant clinical interpretation.

Immunohistochemical and FISH analysis of EGFR and its prognostic value in patients with oral squamous cell carcinoma

OBJECTIVES To study immunohistochemical expression of the epithelial growth factor receptor (EGFR) in oral carcinomas and the head and neck region to examine possible associations with various features of the tumors and survival of the patients. MATERIALS AND METHODS Sections were made from two tissue arrays composed of 206 oral squamous cell carcinomas and 427 squamous cell carcinomas of the head and neck region, respectively, and examined for EGFR expression and Ki-67 labeling index by means of immunohistochemistry, and for EGFR gene amplification by means of fluorescence in situ hybridization. Correlation between resulting parameters and with clinical features was evaluated using chi-square test and Kaplan-Meyer analysis. RESULTS A statistically significant association was observed for strong EGFR immunohistochemical (IHC) expression with advanced lymph node involvement (P = 0.02). EGFR immunohistochemical expression did not significantly correlate with patient disease specific (DS) or overall survival (OS). EGFR gene amplification was not correlated with any of the tumor features nor to survival of the patients (DS and OS). DISCUSSION Epithelial growth factor receptor IHC expression and gene amplification might be suitable to predict locoregional control in oral squamous cell carcinoma patients but an inappropriate predictor for patients survival.

Squamous cell carcinoma of the oral cavity and circulating tumour cells.

Due to a lack of substantial improvement in the outcome of patients suffering from oral squamous cell carcinoma (OSCC) during the past decades, current staging methods need to be revised. This disease is associated with poor survival rates despite considerable advances in diagnosis and treatment. The early detection of metastases is an important indicator of survival, prognosis and relapse. Therefore, a better understanding of the mechanisms underlying metastasis is crucial. Exploring alternative measures apart from common procedures is needed to identify new prognostic markers. Similar to previous findings predominantly for other solid tumours, recently published studies demonstrate that circulating tumour cells (CTCs) and disseminated tumour cells (DTCs) might serve as prognostic markers and could supplement routine staging in OSCC. Thus, the detection of CTCs/DTCs is a promising tool to determine the individual need for therapeutic intervention. Encouraging results and new approaches point to the future use of targeted therapies for OSCC, an exceedingly heterogeneous subgroup of head and neck cancer. This review focuses on summarising technologies currently used to detect CTCs/DTCs. The translational relevance for OSCC is highlighted. The inherent challenges in detecting CTCs/DTCs will be emphasised.

Intraosseous heat generation during sonic, ultrasonic and conventional osteotomy.

OBJECTIVES To assess heat generation in osteotomies during application of sonic and ultrasonic saws compared to conventional bur. METHODS Two glass-fiber isolated nickel-chromium thermocouples, connected to a recording device, were inserted into fresh bovine rib bone blocks and kept in 20 ± 0.5 °C water at determined depths of 1.5 mm (cortical layer) and 7 mm (cancellous layer) and 1.0 mm away from the planned osteotomy site. Handpieces, angulated 24-32°, were mounted in a vertical drill stand, and standardized weights were attached to their tops to exert loads of 5, 8, 15 and 20 N. Irrigation volumes of 20, 50 and 80 ml/min were used for each load. Ten repetitions were conducted using new tips each time for each test condition. The Mann-Whitney-U test was used for statistical analysis (p < 0.05). RESULTS Both ultrasonic and sonic osteotomies were associated with significantly lower heat generation than conventional osteotomy (p < 0.01). Sonic osteotomy showed non-significantly lower heat generation than ultrasonic osteotomy. Generated heat never exceeded the critical limit of 47 °C in any system. Variation of load had no effect on heat generation in both bone layers for all tested systems. An increased irrigation volume resulted in lower temperatures in both cortical and cancellous bone layers during all tested osteotomies. CONCLUSION Although none of the systems under the conditions of the present study resulted in critical heat generation, the application of ultrasonic and sonic osteotomy systems was associated with lower heat generation compared to the conventional saw osteotomy. Copious irrigation seems to play a critical role in preventing heat generation in the osteotomy site.

Long-term biomechanical analysis of donor site morbidity after radial forearm free flap.

BACKGROUND Although the radial forearm free flap (RFF) is a commonly used microvascular graft for head and neck reconstruction, long-term biomechanical results regarding donor site morbidity are rare. PATIENTS AND METHODS In a prospective panel study, 32 patients were included. Biomechanical assessment was performed preoperatively, three months postoperatively and two years postoperatively. The primary endpoint of the study was grip strength. In addition, the Mayo wrist score, DASH score (disabilities of the arm, shoulder and hand score), fine motor skill strengths (tip pinch, key pinch, palmar pinch) and the range of motion were analysed. Primary defects were closed with local full-thickness skin grafts (FTSG) from the donor site forearm avoiding a secondary defect site. RESULTS In the long-term analysis, grip strength was reduced in both arms. A significant improvement over time was found only for the donor arm. A persistent deficit of tip pinch strength and dorsal extension was recorded. Persistent sensory limitations occurred in four cases. Patient contentment after two years of follow-up was high and daily life routine was not restricted. CONCLUSION Gross and fine motor skill limitations are reversible short-term effects after RFF harvesting and do not restrict daily routine in the long term. These findings substantiate the value of the RFF as a workhorse in reconstructive surgery.

Postoperative Bleeding Risk for Oral Surgery under Continued Clopidogrel Antiplatelet Therapy

Object. To determine the incidence of postoperative bleeding for oral osteotomy carried out under continued monoantiplatelet therapy with clopidogrel and dual therapy with clopidogrel/aspirin. Design. Retrospective single center observatory study of two study groups and a control group. Methods. A total of 64 and 60 oral osteotomy procedures carried out under continued monoclopidogrel therapy and dual clopidogrel/aspirin therapy, respectively, were followed for two weeks for postoperative bleeding. Another 281 similar procedures were also followed as a control group. All oral osteotomy procedures were carried out on an outpatient basis. Results. We observed postoperative bleeding in 2/281 (0.7%) cases in the control group, in 1/64 (1.6%) cases in the clopidogrel group, and in 2/60 (3.3%) cases in the dual clopidogrel/aspirin group. The corresponding 95% confidence intervals are 0–1.7%, 0–4.7%, and 0–7.8%, respectively, and the incidences did not differ significantly among the three groups (P > 0.09). Postoperative hemorrhage was treated successfully in all cases with local measures. No changes of antiplatelet medication, transfusion, nor hospitalisation were necessary. No major cardiovascular events were recorded. Conclusions. Our results indicate that minor oral surgery can be performed safely under continued monoantiplatelet medication with clopidogrel or dual antiplatelet medication with clopidogrel/aspirin.

Linear accuracy and reliability of volume data sets acquired by two CBCT-devices and an MSCT using virtual models : A comparative in-vitro study

Abstract Objective. To discriminate clinically relevant aberrance, the accuracy of linear measurements in three-dimensional (3D) reconstructed datasets was investigated. Materials and methods. Three partly edentulous human skulls were examined. Landmarks were defined prior to acquisition. Two CBCT-scanners and a Quad-slice CT-scanner were used. Actual distances were physically measured with calipers and defined as a reference. Subsequently, from digital DICOM datasets, 3D virtual models were generated using maximum intensity projections (MIPs). Linear measurements were performed by semi-automated image analysis. Virtual and analogue linear measurements were compared using repeated measurements in a mixed model (p ≤ 0.05). Results. No significant difference was found among all of the digital measurements when compared to one another, whereas a significant difference was found in matched-pairs analysis between CBCT and calipers (p = 0.032). All digitally acquired data resulted in lower mean values compared to the measurements via calipers. A high level of inter-observer reliability was obtained in the digital measurements (inter-rater correlation = 0.988–0.993). Conclusions. The reconstructed datasets led to highly consistent values among linear measurements. Yielding sub-millimeter precision, these modalities are assumed to reflect reality in a clinically irrelevant altered manner. During data acquisition and evaluation, a maximum of precision must be achieved.

Prospective biomechanical evaluation of donor site morbidity after radial forearm free flap.

Although the radial forearm free flap (RFF) is a commonly-used microvascular flap for orofacial reconstruction, we are aware of few prospective biomechanical studies of the donor site. We have therefore evaluated the donor site morbidity biomechanically of 30 consecutive RFF for orofacial reconstruction preoperatively and three months postoperatively. This included the Mayo wrist score, the Disabilities of the Arm, Shoulder and Hand (DASH) score, grip strength, followed by tip pinch, key pinch, palmar pinch, and range of movement of the wrist. Primary defects were all closed with local full-thickness skin grafts from the donor site forearm, thereby circumventing the need for a second defect. Postoperative functional results showed that there was a reduction in hand strength measured by (grip strength: -24.1%, in tip pinch: -23.3%, in key pinch: -16.5, and in palmar pinch: -19.3%); and wrist movement measured by extension (active=14.3% / passive= -11.5%) and flexion = -14.8% / -8.9%), and radial (-9.8% / -9.8%) and ulnar (-11.0% / -9.3%) abduction. The Mayo wrist score was reduced by 9.4 points (-12.9%) and the DASH score increased by 16.1 points (+35.5%) compared with the same forearm preoperatively. The local skin graft resulted in a robust wound cover with a good functional result. Our results show that the reduction in hand strength and wrist movement after harvest of a RFF is objectively evaluable, and did not reflect the subjectively noticed extent and restrictions in activities of daily living. Use of a local skin graft avoids a second donor site and the disadvantages of a split-thickness skin graft.

Thromboelastometry: A contribution to perioperative free-flap management

BACKGROUND Microvascular tissue transfer is a fundamental part of reconstructive surgery. Different perioperative anticoagulation regimens exist, influencing hemostatic parameters. Since bleeding and thrombosis are major reasons for revision procedures and flap loss, current practice regarding anticoagulative treatment needs further refinement. Thromboelastometry has been demonstrated as worthwhile in the determination of alterations of the anticoagulation cascade. We evaluated this aspect of thromboelastometry for free flap surgery. METHODS Thirty-five patients undergoing free-flap surgery were enrolled in this study. Blood samples were obtained at three time points: at the beginning of surgery, at time of anastomosis and after 24 h. At each time point, thromboelastometry with special regard to clotting times for the intrinsic and extrinsic paths of coagulation was immediately performed. Global coagulation markers and clinical parameters were collected simultaneously. RESULTS Hemostatic changes were deducible using thromboelastometry perioperatively. Measured parameters differed significantly over time (p < 0.05). Heparin therapy showed a significant effect on the measured slope of INTEM-clotting times (p < 0.001). Altered values of thromboelastometry suggested non-inferiority to standard testing. Neither standard testing nor thromboelastometry were capable of predicting adverse events such as thrombosis, bleeding or flap loss (p > 0.05). CONCLUSIONS Thromboelastometry monitors hemostatic effects almost in real-time and could serve as a supplementary tool in microvascular tissue transfer once its use has been standardized. The utilization of thromboelastometry allows for assessment of the anticoagulation needs of individual patients undergoing free flap surgery, which is frequently accompanied by hemostatic changes in the perioperative setting. Our findings implicate further validation of thromboelastometry in free-flap surgery.