Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1)—A Prospective Multicentric Cohort Study

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55–1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15–0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19–0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

Clinical and radiographic performance of self-locking conical connection implants in the posterior mandible: Five-year results of a two-centre prospective study

OBJECTIVE

This prospective study aims to assess the 5-year clinical performance of implants with internal conical connection and platform-switched abutments in the posterior mandible.

MATERIAL AND METHODS

Healthy adults missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent implants. After a transmucosal healing period single crown restorations were cemented on platform-switched abutments. Changes in marginal bone levels were investigated in standardized periapical radiographs from surgery and loading (baseline) to 60-months post-loading.

RESULTS

Twenty-four patients received 52 implants. Bone remodelling took place between surgery and loading (mean:-0.5, SD:±0.4 mm). From loading to 60 months, there was a mean bone change of 0.27 (SD:±0.47 mm) which stabilized 24 months after prosthesis delivery (mean:0.2, SD:±0.46 mm). 71.7% of all implants presented bone preservation at 60 months irrespective of the initial insertion depth. Two implants were lost after 5 years and the success rate was 95.1%. Patient enquiry revealed high satisfaction.

CONCLUSION

Internal conical connection implants with platform-switched abutments presented a high success rate and preservation of marginal bone levels at the implant shoulder after 5 years of loading.

Peri-implant marginal bone loss reduction with platform-switching components: 5-Year post-loading results of an equivalence randomized clinical trial

AIM

To compare the clinical performance and marginal bone levels of implants restored with platform-switching (PS) or platform-matching (PM) abutments.

MATERIALS AND METHODS

Adult patients missing two or more adjacent teeth in the posterior mandible received 2-4 CAMLOG SCREW-LINE implants and were randomly allocated to the PM or PS group, receiving the corresponding prosthetic components from surgery onwards. Implants were conventionally loaded with single cemented crowns. Patients were followed annually for 5 years. Outcome measures were marginal bone level changes, implant survival, performance of the prosthetic components and clinical parameters plaque index, sulcus bleeding index and pocket probing depth.

RESULTS

Thirty-three patients received 72 implants in the PM group, and thirty-five patients received 74 implants in the PS group. Sixty patients attended the final appointment, 31 had received PS components and 29 had received PM components with 65 and 63 implants, respectively. Global survival rate was 96.6% with no differences between groups (p = 0.647). After 5 years of functional loading, PS restored implants presented 0.23mm (95% CI: [0.03, 0.43], p = 0.025) lower marginal bone level changes. The two groups were declared non-equivalent.

CONCLUSION

Patients requiring implant supported restorations in healed bounded or free end edentulous gaps of the mandible benefit from the use of PS components in terms of peri-implant marginal bone level maintenance, though it may not be clinically noticeable.

Integration of Perforator Vessels in CAD/CAM Free Fibula Graft Planning: A Clinical Feasibility Study

Introduction

Commercial CAD/CAM planning of free osteocutaneous microvascular fibula flap does not support integration of soft tissue structures including perforator vessel anatomy. Therefore, in a clinical trial, a method for such a combined hard- and soft tissue 3D-fibula planning was assessed.

Materials and Methods

In a clinical study on 24 patients needing reconstruction with osteocutaneous fibula graft, skin perforators of the respective leg were detected via Doppler sonography and documented on a measurement device. Each of the perforators' localization was transferred to a CAD/CAM planning software and included in each planning step as well as in the surgical cutting guide. A comparison between sonography and clinical localization, damage to perforator vessels during surgery as well as a subjective evaluation of feasibility and usefulness of the procedure was carried out.

Results

In total, 19 skin paddles were placed orally, 2 extraorally and 3 at both sites at once. Survival rate was 92% (22/24). In addition, 3 skin paddles were lost complete and 2 partially. Anatomical sites of perforator vessels were never < 1 cm from planned positions and not damaged at all (n = 75). Planning was judged useful for skin paddle design and positioning of osteotomies. In accordance, surgical guides were always implemented successfully without the need of changing planned procedures during surgery.

Conclusion

Integration of skin perforators into 3D planning of microvascular fibular graft is feasible and may even decrease involuntary dissection of perforator vessels. Even so, clinical studies for comparison are needed.

Predictive values of resonance frequency analysis as a diagnostic tool in palatal implant loss

OBJECTIVES

To determine the diagnostic value of resonance frequency analysis (RFA) in predicting palatal implant (PI) loss.

MATERIALS AND METHODS

RFA values of 32 patients (study center at Mainz and Dresden) were evaluated in a prospective randomized controlled trial addressing clinical performance of two loading concepts on PI (Orthosystem, Straumann, Basel, Switzerland). Group 1: conventional loading after a 12-week healing period vs group 2: immediate loading within one week after insertion. Stability was assessed by RFA after surgical insertion (T1), one week (T2), and 12 weeks (T3) later.

RESULTS

All 32 PI were clinically stable after surgical insertion; 14 PI were loaded conventionally and 18 immediately. One implant in group 1 was lost 6 weeks after insertion. One drop-out was registered in group 2. One false positive and three false negative implant stability quotients (ISQ) were observed. ISQ values of clinically stable PI in group 1 were 67.2 (SD ± 9.5) at T1, 62.3 (SD ± 11.7) at T2, and 68.2 (SD ± 5.5) at T3. Group 2 showed 67.1 (SD ± 11.7) at T1, 65.4 (SD ± 10.4) at T2, and 72.3 (SD ± 5.6) at T3. Differences between groups were not statistically significant for starting time (P = .88) and change from T1 to T2: 0.08 but were significant from T1 to T3: P = .04; (regression analysis).

CONCLUSIONS

RFA had no sensitivity for prediction of stability. General decrease after primary stability and increase with secondary stability gives support for specificity. Within the limits of the study, only the diagnostic value of RFA identifying stable palatal implants could be confirmed.

Immediate and flapless implant insertion and provisionalization using autogenous bone grafts in the esthetic zone: 5-year results

OBJECTIVES

As the 2-year results for immediately inserted and provisionalized implants have been reported, it remained an open issue, whether the initially high success rates and the esthetic outcome remain stable for longer observation periods. Therefore, this prospective study examines the 5-year hard and soft tissue changes at implants placed in the anterior maxilla.

MATERIAL AND METHODS

Meanwhile, 37 microthreaded implants were placed in 21 patients into extraction sockets with and without facial bone deficiencies by a flapless approach. Facial gaps and bony defects were grafted with autogenous bone chips. The implants were immediately provisionalized. The primary outcome parameters were the interproximal marginal bone level and the thickness of the facial bony wall. Implant success and Pink Esthetic Score (PES) were considered as secondary outcome parameters.

RESULTS

Two patients with four implants withdrew from the study (dropouts), and the remaining 33 implants were still in function at a follow-up period of 68 months. Marginal bone height averaged 0.04 mm coronal to the implant shoulder. The thickness of the facial bony lamellae increased significantly between pre-op examination and 1-year follow-up (p = .002) and thereafter remained stable. Within 5 years of follow-up, 24 of 33 implants were clinically stable, free of signs and symptoms, and showed bone loss less than 1 mm. The mean PES ratings improved slightly from 10.7 pre-operatively to 11.7 at the last follow-up (p = .02).

CONCLUSIONS

Interproximal marginal bone levels, survival rates, and esthetic results remain stable at the 5-year follow-up in implants used in an immediate insertion, reconstruction, and provisionalization concept. Facial marginal bone levels decreased slightly; however, this reduction did not affect the PES so far.

Leech related Aeromonas veronii complex infection after reconstruction with a microvascular forearm flap

Medical leeches (Hirudo medicinalis) in plastic and reconstructive surgery are often used for the treatment of vascular failure after microvascular surgery. Leeches are a reservoir for bacteria of the Aeromonas group that help digesting the blood meal. In some cases these bacteria are able to cause severe wound infections that can lead to loss of tissue transplants. We report about a patient with a common microvascular forearm flap after resection of an oral squamous cell carcinoma which got infected by Aeromonas spp. after treatment with medical leeches. Most of these species are resistant for common antibiotic treatment after surgery. This report shows the importance of an early concomitant antibiotic prophylaxis in the treatment of venous congestion with medical leeches.

Clinical outcome of alveolar ridge augmentation with individualized CAD-CAM-produced titanium mesh

Background

The augmentation of the jaw has been and continues to be a sophisticated therapy in implantology. Modern CAD-CAM technologies lead to revival of old and established augmentation techniques such as the use of titanium mesh (TM) for bone augmentation. The aim of this retrospective study was to evaluate the clinical outcome of an individualized CAD-CAM-produced TM based on the CT/DVT-DICOM data of the patients for the first time.

Methods

In 17 patients, 21 different regions were augmented with an individualized CAD-CAM-produced TM (Yxoss CBR®, Filderstadt, Germany). For the augmentation, a mixture of autologous bone and deproteinized bovine bone mineral (DBBM) or autologous bone alone was used. Reentry with explantation of the TM and simultaneous implantation of 44 implants were performed after 6 months. Preoperative and 6-month postoperative cone beam computed tomographies (CBCT) were performed to measure the gained bone height.

Results

The success rate for the bone grafting procedure was 100%. Thirty-three percent of cases presented an exposure of the TM during the healing period. However, premature removal of these exposed meshes was not necessary. Exposure rate in augmentations performed with mid-crestal incisions was higher than in augmentations performed with a modified poncho incision (45.5 vs. 20%, p = 0.221). In addition, exposure rates in the maxilla were significantly higher than in the mandible (66.7 vs. 8.3%, p = 0.009). Gender, smoking, periodontal disease, gingiva type, used augmentation material, and used membrane had no significant influence on the exposure rate (p > 0.05). The mean vertical augmentation was 6.5 ± 1.7 mm, and the mean horizontal augmentation was 5.5 ± 1.9 mm. Implant survival rate after a mean follow-up of 12 ± 6 months after reentry was 100%.

Conclusion

Within the limits of the retrospective character of this study, this study shows for the first time that individualized CAD-CAM TM provide a sufficient and safe augmentation technique, especially for vertical and combined defects. However, the soft tissue handling for sufficient mesh covering remains one of the most critical steps using this technique.

Biofunctionalization of porcine-derived collagen matrix using enamel matrix derivative and platelet-rich fibrin: influence on mature endothelial cell characteristics in vitro

OBJECTIVES

The present study evaluated the effect of an enamel matrix derivative (EMD) and platelet-rich fibrin (PRF)-modified porcine-derived collagen matrix (PDCM) on human umbilical vein endothelial cells (HUVEC) in vitro.

MATERIALS AND METHODS

PDCM (mucoderm®) was prepared to 6 mm (±0.1 mm) diameter discs. PDCM samples were incubated with either EMD, PRF, or control solutions for 100 min at 4 °C before the experiments. Cell-inducing properties of test materials on HUVEC cells were tested with cell proliferation assays (MTT, PrestoBlue®), a cytotoxicity assay (ToxiLight®), a Boyden chamber migration assay, and a cell attachment assay. Scanning electron microscopy (SEM) imaging was performed to determine the surface and the architecture of the modified matrices.

RESULTS

Cell proliferation was elevated in the EMD and PRF groups compared with control (p each ≤0.046). PRF modification increased HUVEC migration ability by 8-fold compared with both control and EMD groups (p each <0.001). Both treatments significantly promoted the cell attachment of HUVEC to PDCM, as assessed by direct cell counts on the matrices (p each <0.001).

CONCLUSIONS

HUVEC cell characteristics were overall improved by EMD- and PRF- modified PDCM. Adsorbed bioactive molecules to the PDCM surface may have contributed to a more preferable environment to surrounding cells.

CLINICAL RELEVANCE

The results may give evidence that PDCM modification with EMD or PRF, respectively, might be a useful approach to improve clinical outcomes, to prevent inflammatory reactions and wound-healing disturbances, and to expand the clinical application area of PDCM.

Accelerated workflow for primary jaw reconstruction with microvascular fibula graft

Introduction

Major facial defects due to cancer or deformities can be reconstructed through microvascular osteocutaneous flaps. Hereby CAD/CAM workflows offer a possibility to optimize reconstruct and reduce surgical time. We present a retrospectiv observational study regarding the developement of an in-house workflow allowing an accelerated CAD/CAM fibula reconstruction without outsourcing.

Case description

Workflow includes data acquisition through computertomography of head and legs, segmentation of the data and virtual surgery. The virtual surgery was transferred into surgical guides and prebent osteosynthesis plate. Those were sterilized and used in surgery.

Evaluation

The workflow was used in 30 cases. Minimum planning period took 4 days from CT to surgery, average time was 8 days. Planning could be transferred to surgery every time. Intraoperative complications regarding osteotomy, assembly and fixation did not occur.

Discussion/Conclusion

An in-house workflow for CAD/CAM fibula reconstruction is feasible within a few days providing an accelerated procedure even in urgent cases.

Effect of platform switching on crestal bone levels around implants in the posterior mandible: 3 years results from a multicentre randomized clinical trial

Objective

Evaluation of differences in the clinical performance and crestal bone levels between implants restored with single crowns with platform‐matched or platform‐switched abutments after 3 years.

Material and Methods

The study enrolled adult patients missing two or more adjacent teeth in the posterior mandible with natural teeth mesial to the implant site. Randomization followed open‐flap implant insertion and the corresponding matching or switching healing abutments placed at surgery. Conventional loading was made with cemented crowns. Clinical follow‐up took place annually after loading up to 3 years. Bone level changes were measured in standardized radiographs as the variation in crestal bone from one evaluation to the next.

Results

Sixty‐three patients with a total of 135 implants (66 platform matching, 69 platform switching) were analysed. From surgery to 36 months, mean bone loss was 0.28 ± 0.56 mm for the platform‐switching group and 0.68 ± 0.64 mm for the platform‐matching group. A statistically significant difference was found between groups (p = 0.002) with an estimate of 0.39 mm (0.15–0.64, 95% CI) in favour of platform switching.

Conclusions

After 3 years, platform‐switching restorations showed a significant effect in the preservation of marginal bone levels compared to platform‐matching restorations.

Radiographic evaluation of conical tapered platform-switched implants in the posterior mandible: 1-year results of a two-center prospective study

OBJECTIVE

Long-term success of dental implants depends on healthy peri-implant soft tissues and adequate bone levels. This prospective study aims to assess bone level changes around implants with internal conical connection and platform-switching abutments in the posterior mandible.

MATERIAL AND METHODS

Adult patients missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent internal conical connection implants. After a minimum transmucosal healing period of 8 weeks, single crown restorations were cemented over platform-switching abutments. Changes in marginal bone levels were measured in standardized periapical radiographs from surgery and loading (baseline) to 12 months post-loading.

RESULTS

Twenty-four patients received 52 implants. Bone remodeling took place between surgery and loading (-0.53 ± 0.40 mm). From loading to 12 months, there was a mean bone gain of 0.12 ± 0.42 mm which occurred mainly in the first 6 months after prosthesis delivery (0.11 ± 0.36 mm) and stabilized afterward. A total of 71.7% of all implants presented bone preservation or gain. No implant was lost at 1 year and the success rate was 100%. Patient inquiry revealed high satisfaction.

CONCLUSION

Internal conical connection implants with platform-switching abutments presented high success rate and enhancement or preservation of marginal bone levels after 1 year of loading.

Platform switch versus platform match in the posterior mandible – 1-year results of a multicentre randomized clinical trial

Objective

The purpose of this ongoing randomized study was to assess differences in bone level changes and success rates using implants supporting single crowns in the posterior mandible either with platform matched or platform switched abutments.

Material and Methods

Patients aged 18 and above, missing at least two teeth in the posterior mandible and with a natural tooth mesial to the most proximal implant site were enrolled. Randomization followed implant placement. Definitive restorations were placed after a minimum transgingival healing period of 8 weeks. Changes in crestal bone level from surgery and loading (baseline) to 12-month post-loading were radiographically measured. Implant survival and success were determined.

Results

Sixty-eight patients received 74 implants in the platform switching group and 72 in the other one. The difference of mean marginal bone level change from surgery to 12 months was significant between groups (p < 0.004). Radiographical mean bone gain or no bone loss from loading was noted for 67.1% of the platform switching and 49.2% of the platform matching implants. Implant success rates were 97.3% and 100%, respectively.

Conclusions

Within the same implant system the platform switching concept showed a positive effect on marginal bone levels when compared with restorations with platform matching.

Chronic periodontitis and its possible association with oral squamous cell carcinoma - a retrospective case control study

Introduction

Different inflammatory processes may trigger the development of malignancies. Therefore, the aim of the present study was to evaluate a potential association between radiological determined chronic periodontitis (CPA) and oral squamous cell carcinoma (OSCC).

Methods

In a retrospective study, OSCC-patients and a control group without malignant tumors were radiographically examined for bone loss. Via telephone survey and questionnaire, general clinical data on the individual oral hygiene and concomitant diseases together with tobacco and alcohol use were assessed and data were compared between the groups.

Results

178 OSCC-patients and 123 controls were included. In univariate analysis, a statistically relevant higher mean bone loss was seen in the OSCC group (4.3 mm (SD: 1.8; 95% confidence interval (CI): 4-4.6) vs. 2.9 mm (SD: 0.7; 95% CI: 2.8-3); p < 0.001)). This was confirmed in a multivariate regression model (OR: 2.4, 95% CI: 1.5-3.8; p < 0.001). A history of periodontal treatment was associated with significantly reduced OSCC risk (p < 0.001; OR: 0.2, CI: 0.1-0.5).

Conclusions

CPA is a common disease and the monitoring as well as the treatment of such a chronic oral inflammation may be beneficial in reducing one potential cause of OSCC. Therefore, further clinical studies on oral neoplasms should consider clinical periodontal parameters as well.

Influence of osteotomy procedure and surgical experience on early complications after orthognathic surgery in the mandible

INTRODUCTION

This study evaluated the influence of osteotomy procedure and surgical experience on early complication rates following orthognathic surgery in the mandible.

MATERIALS AND METHODS

In a retrospective study, patients who underwent a mandibular osteotomy (Obwegeser-Dal Pont (ODP) and Hunsuk-Epker (HE)) were included. Incidence of "bad splits", "bleeding episodes", "delayed wound healing", "failed osteosynthesis" and "nerve lesions" at 2 months post-operatively were recorded. Surgical experience was classified as: beginner (<10), intermediate (10-40) and expert (>40). Complications were correlated to the surgical approach and the experience level of the surgeon.

RESULTS

400 patients were included. 200 underwent a bimaxillary approach. 186 patients were operated using the ODP technique, 214 according to HE. Multivariate analysis confirmed significantly more unwanted fractures and bleeding events for ODP when compared to HE (p = 0.28, p = 0.003). Experienced surgeons had more osteosynthesis failures (0.047) and significantly more nerve lesions than the other groups (p = 0.01).

DISCUSSION

The HE osteotomy showed a more reliable fracture mechanism with less relevant bleeding episodes. Differences between the surgeons of varying training status were marginal with exception of a higher rate of osteosynthesis failure and temporary hypoesthesia in the experienced group.

Comparison of point-of-care methods for preparation of platelet concentrate (platelet-rich plasma)

PURPOSE

This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production.

MATERIALS AND METHODS

The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay.

RESULTS

The principal differences between the analyzed PRP production methods (blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte, and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor β1 (TGF-β1) showed no differences with regard to age or gender. Platelet counts and TGF-β1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies.

CONCLUSIONS

TGF-β1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i.

Overexpression of p63 is associated with radiation resistance and prognosis in oral squamous cell carcinoma

BACKGROUND

The tumor suppressor homologue p63 is expressed in basal and parabasal layers of intraoral mucosa. Full length transcripts with transactivational domain (TA forms) present with homology to p53 and implicate functions governing cell proliferation, differentiation and apoptosis control. To date studies show an increase of p63 expression in oral dysplasia and additionally high expression levels correlated with poor prognosis for patients with OSCC, whereas a possible link to radiation resistance of tumors has not been investigated yet. In the present study we tested the hypothesis for p63 being a marker of radioresistance and overall survival in OSCC.

METHODS

p63 Expression was labeled by immunohistochemistry in pre-treatment biopsies collected from 33 patients with OSCC. Quantification of the labeling index (Li) based on the relation of p63 positive cells to overall tumor cell count. Histological examination of the resection specimen allowed categorization of the radiation response. Statistical analyses of the association between Li and radiation response were performed. Survival analysis utilized Kaplan-Meier estimates and additionally a Cox regression model was built for p63 (Li), T stage, N-stage and chemotherapy and presented as hazard ratios.

RESULTS

All tumors had enhanced p63 expression. The median Li was 63.1% (range 36-87%). Tumors with a p63 positive cell count>63.1% showed increased resistance to radiation (p=0.027). Overall survival was higher (p=0.001) for patients with low Li (<median value) than those with high Li (>median value) and multivariate Cox regression analysis confirmed the significance of p63 as a prognostic marker of survival.

CONCLUSIONS

The results of this analysis advocate p63 expression in pre-treatment tumor tissue to be a marker of radiation resistance in OSCC, with high expression levels being associated with poor radiation response and shorter survival. The promising results of this biomarker should now be confirmed by a study with larger patient counts.

Effectiveness of adjuvant radiotherapy in patients with oropharyngeal and floor of mouth squamous cell carcinoma and concomitant histological verification of singular ipsilateral cervical lymph node metastasis (pN1-state)--a prospective multicenter randomized controlled clinical trial using a comprehensive cohort design

Background

Modern radiotherapy plays an important role in therapy of advanced head and neck carcinomas. However, no clinical studies have been published addressing the effectiveness of postoperative radiotherapy in patients with small tumor (pT1, pT2) and concomitant ipsilateral metastasis of a single lymph node (pN1), which would provide a basis for a general treatment recommendation.

Methods/Design

The present study is a non-blinded, prospective, multi-center randomized controlled trial (RCT). As the primary clinical endpoint, overall-survival in patients receiving postoperative radiation therapy vs. patients without adjuvant therapy following curative intended surgery is compared. The aim of the study is to enroll 560 adult males and females for 1:1 randomization to one of the two treatment arms (irradiation/no irradiation). Since patients with small tumor (T1/T2) but singular lymph node metastasis are rare and the amount of patients consenting to randomization is not predictable in advance, all patients rejecting randomization will be treated as preferred and enrolled in a prospective observational study (comprehensive cohort design) after giving informed consent. This observational part of the trial will be performed with maximum consistency to the treatment and observation protocol of the RCT. Because the impact of patient preference for a certain treatment option is not calculable, parallel design of RCT and observational study may provide a maximum of evidence and efficacy for evaluation of treatment outcome. Secondary clinical endpoints are as follows: incidence and time to tumor relapse (locoregional relapse, lymph node involvement and distant metastatic spread), Quality of life as reported by EORTC (QLQ-C30 with H&N 35 module), and time from operation to orofacial rehabilitation. All tumors represent a homogeneous clinical state and therefore additional investigation of protein expression levels within resection specimen may serve for establishment of surrogate parameters of patient outcome.

Conclusion

The inherent challenges of a rare clinical condition (pN1) and two substantially different therapy arms would limit the practicality of a classical randomized study. The concept of a Comprehensive Cohort Design combines the preference of a randomized study, with the option of careful data interpretation within an observational study.

Trial registration

ClinicalTrials.gov: NCT00964977

Overexpression of GLUT-1 is associated with resistance to radiotherapy and adverse prognosis in squamous cell carcinoma of the oral cavity

This study tested the hypothesis that GLUT-1 is a marker of radioresistance in oral squamous cell carcinomas (OSCC). A GLUT-1 labeling index (LI) was determined by immunohistochemistry in 40 pretreatment OSCC biopsies. Radiation responses were categorized by histopathology of the resection specimens. Associations between the LI and radiation response, Kaplan-Meier survival estimates and Cox regression analysis for the variables GLUT-1, T-stage, N-stage and chemotherapy were examined. The median LI was 64.2% (range 14-100%). Tumors with >65% of GLUT-1+cells were more resistant to radiation (p=0.023). Overall survival was higher (p=0.044) for subjects with low LI (<median value) than those with high LI (>median value). The Cox regression analysis confirmed the prognostic significance of GLUT-1. Our results indicate that pre-treatment GLUT-1 expression in the tumor is a marker of radioresistance in OSCC, with high expression being associated with poor radiation response and shorter survival.

[Chronic cutaneous infiltration with abscess and fistula formation. A type of clinical course in atypical mycobacteriosis]

BACKGROUND

Cutaneous lesions of atypical mycobacteriosis are very rare in Western Europe. Both the slow disease progression and the rather unspecific clinical appearance of the chronic infiltration render cutaneous mycobacteriosis a diagnostic challenge. In this communication, we present an uncommon, biphasic course of a cutaneous atypical mycobacteriosis.

CASE REPORT

A 3-year-old child was referred to our institution due to submandibular cutaneous infiltration together with subcutaneous abscess formation. There was no carious lesion or other odontogenic potential source of infection. First-line therapy was incision of the abscess and local curettage to obtain a specimen for histologic and microbiologic evaluation, which revealed atypical mycobacteria. In spite of local curettage, only partial remission of the cutaneous infiltration was achieved. When the child was readmitted 9 months later, the lesion had progressed to a scrofulosis-like appearance even though specific antibiotic treatment had been administered. Complete surgical excision of the affected skin and extirpation of the respective lymph node and fistula was performed as second-line therapy. Complete remission was achieved without further adjuvant treatment.

DISCUSSION

Our case demonstrates the problems that may arise with this rare type of mycobacterial infection. In all probability, scratch artifacts due to atopic dermatitis provided the source/entry of the infection in this specific case. Both histopathologic findings and clinical appearance were suggestive of classic cutaneous tuberculosis (tuberculosis cutis colliquativa), although it was in fact an atypical mycobacteriosis. Furthermore, obstinate persistence after minor surgical intervention and even after specific (triple) antibiotic treatment illustrates the difficulties of limited, minimally invasive treatment.