Screening of TGFBR1, TGFBR2, and FLNA in familial mitral valve prolapse

So far only mutations in the filamin A gene (FLNA) have been identified as causing familial mitral valve prolapse (MVP). Previous studies have linked dysregulation of the transforming growth factor beta (TGF-β) cytokine family to MVP. We investigated whether mutations in the TGF-β receptors genes type I (TGFBR1) and II (TGFBR2) underlie isolated familial MVP cases. Eight families with isolated familial MVP were evaluated clinically and genetically. Ventricular arrhythmias were present in five of the eight families and sudden cardiac death occurred in six patients. Tissue obtained during mitral valve surgery or autopsy was available for histological examination in six cases; all demonstrated myxomatous degeneration. A previously described FLNA missense mutation (p.G288R) was identified in one large family, but no mutations were discovered in TGFBR1 or TGFBR2. An FLNA missense mutation was identified in one family but we found no TGFBR1 or TGFBR2 mutations. Our results suggest that TGFBR1 and TGFBR2 mutations do not play a major role in isolated myxomatous valve dystrophy. Screening for FLNA mutations is recommended in familial myxomatous valvular dystrophy, particularly if X-linked inheritance is suspected.

Simultaneous targeting of insulin-like growth factor-1 receptor and anaplastic lymphoma kinase in embryonal and alveolar rhabdomyosarcoma: a rational choice

BACKGROUND

Rhabdomyosarcoma (RMS) is an aggressive soft tissue tumour mainly affecting children and adolescents. Since survival of high-risk patients remains poor, new treatment options are awaited. The aim of this study is to investigate anaplastic lymphoma kinase (ALK) and insulin-like growth factor-1 receptor (IGF-1R) as potential therapeutic targets in RMS.

PATIENTS AND METHODS

One-hundred-and-twelve primary tumours (embryonal RMS (eRMS)86; alveolar RMS (aRMS)26) were collected. Expression of IGF-1R, ALK and downstream pathway proteins was evaluated by immunohistochemistry. The effect of ALK inhibitor NVP-TAE684 (Novartis), IGF-1R antibody R1507 (Roche) and combined treatment was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in cell lines (aRMS Rh30, Rh41; eRMS Rh18, RD).

RESULTS

IGF-1R and ALK expression was observed in 72% and 92% of aRMS and 61% and 39% of eRMS, respectively. Co-expression was observed in 68% of aRMS and 32% of eRMS. Nuclear IGF-1R expression was an adverse prognostic factor in eRMS (5-year survival 46.9 ± 18.7% versus 84.4 ± 5.9%, p=0.006). In vitro, R1507 showed diminished viability predominantly in Rh41. NVP-TAE684 showed diminished viability in Rh41 and Rh30, and to a lesser extent in Rh18 and RD. Simultaneous treatment revealed synergistic activity against Rh41 and Rh30.

CONCLUSION

Co-expression of IGF-1R and ALK is detected in eRMS and particularly in aRMS. As combined inhibition reveals synergistic cytotoxic effects, this combination seems promising and needs further investigation.

Feasibility of vascular endothelial growth factor imaging in human atherosclerotic plaque using (89)Zr-bevacizumab positron emission tomography

Intraplaque angiogenesis is associated with the occurrence of atherosclerotic plaque rupture. Cardiovascular molecular imaging can be used for the detection of rupture-prone plaques. Imaging with radiolabeled bevacizumab, a monoclonal anti-vascular endothelial growth factor (VEGF)-A, can depict VEGF levels corresponding to the angiogenic status in tumors. We determined the feasibility of 89Zr-bevacizumab imaging for the detection of VEGF in carotid endarterectomy (CEA) specimens. Five CEA specimens were coincubated with 89Zr-bevacizumab and aspecific 111In-labeled IgG to determine the specificity of bevacizumab accumulation. In 11 CEA specimens, 89Zr-bevacizumab micro-positron emission tomography (PET) was performed following 2 hours of incubation. Specimens were cut in 4 mm wide segments and were stained for VEGF and CD68. In each segment, the mean percent incubation dose per gram of tissue (%Inc/g) and tissue to background ratio were determined. A 10-fold higher accumulation of 89Zr-bevacizumab compared to 111In-IgG uptake was demonstrated by gamma counting. The mean %Inc/ghot spot was 2.2 ± 0.9 with a hot spot to background ratio of 3.6 ± 0.8. There was a significant correlation between the segmental tissue to background uptake ratio and the VEGF score (ρ  =  .74, p < .001). It is feasible to detect VEGF tissue concentration within CEA specimens using 89Zr-bevacizumab PET. 89Zr-bevacizumab accumulation in plaques is specific and correlates with immunohistochemistry scores.

Application of the ThinPrep imaging system in urine cytology: a prospective study

BACKGROUND

In this prospective study, for the first time, the authors compared the accuracy of reading urine specimens using the ThinPrep Imager System (TIS) with the accuracy of conventional screening for the detection of abnormal urine cells.

METHODS

ThinPrep slides were made from 1455 urine specimens and were read with conventional screening and with TIS. Findings were categorized as "unsatisfactory or failure to read the slide," "benign," or "abnormal." The Cohen κ coefficient was calculated to determine inter-rater agreement between both methods. Urine samples that were followed by biopsies were used to compare the sensitivity, specificity, positive predictive value, and negative predictive value of both methods. From 22 urine specimens, the screening times were measured and compared.

RESULTS

There was substantial agreement between both methods (κ score, 0.77). Of 175 urine specimens that were followed by bladder biopsies, for conventional screening, the sensitivity was 51.3%, specificity was 68.4%, the positive predictive value was 77.2%, and the negative predictive value was 40.2%; for TIS screening, the respective values were 54.6%, 68.4%, 78.3%, and 41.9%. The average time was 5.2 minutes for conventional screening and 3.9 minutes for TIS.

CONCLUSIONS

With a κ score of 0.77, the current study demonstrated a good correlation between reading urine specimens with conventional screening and with TIS. Using TIS resulted in slightly increased sensitivity, positive predictive value, and negative predictive value compared with conventional screening and had the same specificity. These results indicate that reading urine specimens using TIS is equally reliable as conventional cytology.

Effective application of the methanol-based PreservCyt(™) fixative and the Cellient(™) automated cell block processor to diagnostic cytopathology, immunocytochemistry, and molecular biology

We studied the feasibility of immunocytochemistry (ICC), in situ hybridization (ISH), and polymerase chain reaction (PCR) after Cellient(™) automated cell block processing, and tested whether methanol-based PreservCyt(™) fixation could replace formalin fixation, in an attempt to eliminate toxic formaldehyde vapors. Immunostaining with 30 different antibodies was performed on cell blocks from 73 FNA specimens and 42 body cavity fluid specimens prepared by Cellient(™) automated processing that uses the methanol-based fixative (PreservCyt(™) ). For each antibody we evaluated ICC in at least three different cell block specimens and compared it with immunohistochemistry (IHC) in formalin-fixed, paraffin-embedded (FFPE) histological sections from the corresponding tumors. The quality of DNA and RNA in Cellient(™) blocks was analyzed by ISH, applying a SYT gene break-apart assay and EBER probes, respectively. Moreover, DNA quality was analyzed by PCR by using primer sets for DNA products of 100, 200, 300, 400, 500, and 600 base pairs, and evaluated by gel electrophoresis. When compared with IHC results in corresponding FFPE tumor tissue from the same patient, 24 out of 30 antibodies showed concordant ICC results. With FISH, distinctive hybridization signals were observed for SYT DNA sequences and EB virus RNA sequences. With PCR, DNA products, up to 600 base pairs in size, were readily observed after gel electrophoresis. The antibodies that showed concordant immunostaining in Cellient(™) blocks could be applied to diagnostic algorithms that proved to be helpful in the discrimination of major tumor types (carcinoma, lymphoma, melanoma, and germ cell tumors), discrimination of carcinoma subtypes, and determination of primary tumor site in cases of metastatic carcinoma. In a separate study, we found that the application of ICC to this cell block technique provided additional diagnostic and clinically important information in 24% of 100 consecutive cases. The high quality of DNA and RNA in Cellient(™) cell blocks allowed sensitive and specific molecular biologic analysis, in particular FISH and PCR.

[Limb perfusion in soft tissue sarcomas: twenty years of experience]

OBJECTIVE

To evaluate the long-term results of 20 years of experience with isolated limb perfusion (ILP) with tumour necrosis factor α (TNF-α) and melphalan, followed by surgical resection and adjuvant radiotherapy, for the treatment of advanced soft tissue sarcomas of the extremities.

DESIGN

Retrospective cohort study.

METHOD

From 1991 to 2011, 113 patients with primary irresectable soft tissue sarcomas underwent 117 ILPs at the University Medical Centre Groningen. 96 ILPs (82%) were performed in the lower limb, and 21 (18%) in the upper limb. The dosages used were 1-4 mg TNF-α and 10-13 mg/l melphalan.

RESULTS

After a median follow up of 8 (range 2-15) weeks after ILP, 107 tumours were resected: 81 (76%) of the resection margins were tumor-free. After the resection, 69 patients (61%) received adjuvant radiotherapy. In total, 85 ILPs resulted in a tumoural response; 16 patients (14%) developed a local recurrence and after 46 treatments (39%), distant metastases had developed. After a median follow-up of 51 months, the limb had been spared in 88 patients (78%). The 10- year disease-specific survival was 53.8%. There was a median follow-up period of 76 months (range: 7-234); still alive at the end of this period were 56 patients (50%). A total of 83 perfusion- or resection-related complications occurred from 58 ILPs (50%): 55 (66%) early and 28 (34%) late treatment-related complications. None of the patients died as a result of the treatment.

CONCLUSION

ILP is a safe and effective procedure in the treatment of advanced primary irresectable soft tissue sarcoma that can prevent amputation in many cases. It is however associated with significant morbidity and is burdensome for the patient.

The impact of age on outcome of embryonal and alveolar rhabdomyosarcoma patients. A multicenter study

BACKGROUND

The prognosis of rhabdomyosarcoma (RMS) in children and adolescents has improved since the introduction of multi-agent chemotherapy. However, outcome data of adults with RMS are scarce. This multicenter retrospective study investigated the effect of age on outcome of RMS.

PATIENTS AND METHODS

Data were collected from three Dutch University Medical Centers between 1977-2009. The effect of age and clinical prognostic factors on relapse-free and disease-specific survival (DSS) were analyzed.

RESULTS

Age as a continuous variable predicted poor survival in multivariate analysis. Five-year DSS was highest for non-metastatic embryonal RMS, followed by non-metastatic alveolar RMS and was poor in metastatic disease. Higher age correlated with unfavorable histological subtype (alveolar RMS) and with metastatic disease at presentation in embryonal RMS. In non-metastatic embryonal RMS and in all alveolar RMS, higher age was an adverse prognostic factor of outcome.

CONCLUSION

This study indicates that age is a negative predictor of survival in patients with embryonal and alveolar RMS.

Phospholamban R14del mutation in patients diagnosed with dilated cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy: evidence supporting the concept of arrhythmogenic cardiomyopathy

AIMS

To investigate whether phospholamban gene (PLN) mutations underlie patients diagnosed with either arrhythmogenic right ventricular cardiomyopathy (ARVC) or idiopathic dilated cardiomyopathy (DCM).

METHODS AND RESULTS

We screened a cohort of 97 ARVC and 257 DCM unrelated index patients for PLN mutations and evaluated their clinical characteristics. PLN mutation R14del was identified in 12 (12 %) ARVC patients and in 39 (15 %) DCM patients. Haplotype analysis revealed a common founder, estimated to be between 575 and 825 years old. A low voltage electrocardiogram was present in 46 % of R14del carriers. Compared with R14del- DCM patients, R14del+ DCM patients more often demonstrated appropriate implantable cardioverter defibrillator discharge (47 % vs. 10 % , P < 0.001), cardiac transplantation (18 % vs. 2 % , P < 0.001), and a family history for sudden cardiac death (SCD) at < 50 years (36 % vs. 16 % , P = 0.007). We observed a similar pattern in the ARVC patients although this was not statistically significant. The average age of 26 family members who died of SCD was 37.7 years. Immunohistochemistry in available myocardial samples revealed absent/depressed plakoglobin levels at intercalated disks in five of seven (71 %) R14del+ ARVC samples, but in only one of nine (11 %) R14del+ DCM samples (P = 0.03).

CONCLUSIONS

The PLN R14del founder mutation is present in a substantial number of patients clinically diagnosed with DCM or ARVC. R14del+ patients diagnosed with DCM showed an arrhythmogenic phenotype, and SCD at young age can be the presenting symptom. These findings support the concept of 'arrhythmogenic cardiomyopathy'.

Prognostic value of the standardized uptake value for (18)F-fluorodeoxyglucose in patients with stage IIIB melanoma

Purpose

FDG PET/CT is an excellent tool to detect melanoma metastases and also allows quantification of FDG uptake using standardized uptake value (SUV). The aim of this study was to prospectively investigate the potential prognostic value of SUV for disease-free survival (DFS) and disease-specific survival (DSS) for patients with stage IIIB melanoma.

Methods

From November 2003 to March 2008, all consecutive patients were included in the present study. Inclusion criteria were: palpable, histology- or cytology-proven lymph node metastases of melanoma, and referred to the University Medical Centre Groningen for FDG PET and CT examination. Patients without distant metastases were evaluated. Multivariable survival analysis was performed to determine whether SUV was associated with DFS and DSS (Cox proportional hazard analysis).

Results

In 80 patients (without distant metastases, 65 %) SUV could be measured. Overall 5-year DFS was 41 % (95% CI 26–56 %) and 24 % (95% CI 12–38 %) in patients with a low and high SUVmean (p = 0.02), respectively. Overall 5-year DSS was 48 % (95% CI 31–62 %) and 30 % (95% CI 17–45 %) in patients with a low and high SUVmean (p = 0.04), respectively. In the multivariable analysis, SUVmean was associated with DFS (hazard ratio 1.7; p = 0.048), but was not associated with DSS (hazard ratio 1.6; p = 0.1). The number of positive nodes, extranodal growth and gender were also associated with survival.

Conclusion

FDG uptake in clinically overt nodal melanoma metastases is inversely associated with DFS. Univariate analysis showed an association with DSS. However, after adjustment for potential confounders this association was no longer significant. If these findings are confirmed in larger studies, SUVmean could potentially be used (in addition to the number of positive nodes, tumour size and extranodal growth) as a factor in deciding on adjuvant systemic treatment.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-012-2182-0) contains supplementary material, which is available to authorized users.

'Big'-insulin-like growth factor-II signaling is an autocrine survival pathway in gastrointestinal stromal tumors

New treatment targets need to be identified in gastrointestinal stromal tumors (GISTs) to extend the treatment options for patients experiencing failure with small-molecule tyrosine kinase inhibitors, such as imatinib. Insulin-like growth factor (IGF)-II acts as an autocrine factor in several tumor types by binding to IGF receptor type 1 (IGF-1R) and/or the insulin receptor (IR) isoform A. The aim of the present study was to investigate the putative role of unprocessed pro-IGF-II, called 'big'-IGF-II, in GISTs. The imatinib-sensitive GIST882 and imatinib-resistant GIST48 cell lines secrete high levels of big-IGF-II as demonstrated by ELISA and Western blotting analyses. IR isoform A mRNA and protein expression, but not that of IGF-1R, was found in these KIT mutant cell lines and in KIT and platelet-derived growth factor receptor α-mutant GIST specimens. Down-regulation of either big-IGF-II or IR affected AKT and MAPK signaling and reduced survival in both cell lines. Disruption of big-IGF-II signaling in combination with imatinib had additive cytotoxic effects on GIST882 cells. IGF-II mRNA as determined by in situ hybridization was present in 91% of 60 primary GISTs. Immunohistochemical analysis of big-IGF-II protein expression was associated with moderate- to high-risk tumors compared with tumors with a lower risk classification (P < 0.028). Our data put forth the big-IGF-II/IR isoform A axis as an autocrine survival pathway and potential therapeutic target in GISTs.

NR4A3 rearrangement reliably distinguishes between the clinicopathologically overlapping entities myoepithelial carcinoma of soft tissue and cellular extraskeletal myxoid chondrosarcoma

Myoepithelial carcinoma of soft tissue (MEC) and cellular extraskeletal myxoid chondrosarcoma (cEMC) share striking similarities. In this paper, we compare ten MECs with five cEMCs. MEC patients had an equal gender distribution. The age range was 15–76 years (mean, 42 years). Tumours were located on extremities, pelvic girdle, vulva and neck. Follow-up, available for nine patients, ranged from 4 to 85 months (mean, 35 months). Five patients were alive without evidence of disease, two were alive with disease and two died 8 months after the initial diagnosis. cEMCs were from three males and two females with an age range of 37–82 years (mean, 57 years); they presented in extremities, shoulder and paravertebral/cervical. Follow-up, available for four patients, ranged from 6 to 220 months (mean, 61 months). All patients were alive, two with recurrences and/or metastases and two without evidence of disease. Morphologically, the distinction between these two entities was difficult since all cases exhibited features typically seen in myoepithelial tumours. Immunohistochemically, MECs expressed pan-keratin (80 %), epithelial membrane antigen (EMA; 57 %), S100 (50 %), alpha-smooth muscle actin (ASMA; 75 %), calponin (67 %) and p63 (25 %). S100 and EMA were expressed in 40 % of cEMC cases respectively with additional immunoreactivity for p63, ASMA and glial fibrillary acidic protein in one case. Pan-keratin was negative in all neoplasms. NR4A3 rearrangement was present in four of four cEMCs and in none of the MECs. In contrast, three of nine (33 %) MECs and four of five (80 %) cEMCs showed an EWSR1 rearrangement. In summary, MECs and cEMCs share clinical, morphological, immunohistochemical and genetic characteristics. The pathognomic rearrangement of NR4A3 is a useful diagnostic feature in identifying cEMCs.

Radiation-associated angiosarcoma after breast cancer: high recurrence rate and poor survival despite surgical treatment with R0 resection

Background

Secondary angiosarcoma of the breast is a rare but severe long-term complication of breast cancer treated with breast-conserving surgery and radiotherapy. We characterized a population-based cohort of patients with secondary angiosarcomas from two tertiary hospitals to investigate this complication with respect to surgical treatment and outcome.

Methods

We identified 35 patients with a history of radiation for breast cancer that developed angiosarcoma in the irradiated field from 1990 to 2009. Of these, 31 underwent surgery and were included for analysis.

Results

Angiosarcoma developed after median 7 years (range 3–25 years). R0 resection was obtained in 23 of 31 patients after primary treatment. Local recurrence developed in 19 patients after median 6 months (range 1–89 months). Regional and distant metastases occurred in 13 patients after median 17 months (range 2–50 months); nine which also had local recurrence. Patients whose local recurrence could be operated on had a better survival after treatment than those who were not considered for surgical treatment, median 34 months (range 6–84 months) compared with 6 months (range 5–24 months). The median disease-free survival and disease-specific survival was 16 and 37 months, respectively.

Conclusions

Despite R0 resection, two-thirds of the patients developed a local recurrence. Survival among those with local recurrence was better if the patient could be treated with surgery. Overall, the prognosis was dismal and median DSS was just over 3 years.

Use of S-100B to evaluate therapy effects during bevacizumab induction treatment in AJCC stage III melanoma

AIM

To investigate the feasibility of using bevacizumab to improve the survival of American Joint Committee on Cancer (AJCC) stage III melanoma patients, we investigated how a single bevacizumab treatment affected nodal disease and a panel of biomarkers in clinically fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT)-staged, stage III melanoma patients, prior to therapeutic lymph node dissection (TLND).

METHODS

Four weeks before TLND, nine patients (median age 50, range 28.8-62.1 years; two male, seven female) with palpable lymph node metastases received 7.5 mg/kg bevacizumab. Before and after this treatment, all patients were assessed by measurements of the maximum standardized uptake value (SUVmax) by FDG-PET scan, and serum S-100B and lactate dehydrogenase (LDH). After TLND, the dissection specimen was analyzed for number of removed lymph nodes, number of metastatic lymph nodes, and tumor necrosis.

RESULTS

Median follow-up was 15.5 (2.2-32.9) months. Histopathological analysis revealed tumor necrosis in six patients, of whom five had an S-100B decline and one had an unchanged S-100B level after bevacizumab. The other three patients showed an S-100B increase and no necrosis. Tumor necrosis was correlated with S-100B decrease (P = 0.048). No association was found between necrosis and the markers SUVmax and LDH. No wound healing disturbances were encountered.

CONCLUSION

Tumor necrosis in dissection specimens was associated with declining S-100B levels, while elevated S-100B was only found in cases with no necrosis. Bevacizumab might be useful in treating AJCC stage III melanoma patients prior to TLND, and S100-B appears to be a useful marker for assessment of treatment effects.

Procedure-related, false-positive cytology results during EUS-guided FNA in patients with esophageal cancer

BACKGROUND

EUS is a standard staging procedure in esophageal cancer. For adequate staging, FNA of suspicious lymph nodes is recommended. Based on optimal staging, sophisticated treatment can be applied more properly. The working channel of the endoscope can potentially be contaminated by cancer cells derived from the luminal surface of esophageal cancer during EUS-guided FNA, which may result in false-positive cytology results of EUS-guided FNA of celiac lymph nodes.

OBJECTIVE

To determine whether passing an endoscope through intraluminal esophageal cancer can lead to contamination of the working channel with tumor cells.

DESIGN

An ex vivo assessment of contamination of endoscope working channels.

SETTING

University hospital.

PATIENTS

This study involved 13 patients with esophageal cancer.

INTERVENTION

Working channels of endoscopes that had been used in patients with intraluminal esophageal cancer were studied immediately after EUS. A routine ex vivo FNA was performed through the endoscope on 8 patients. The same procedure was performed through the endoscope on 5 other patients after the working channel had been cleaned by extensive flushing.

MAIN OUTCOME MEASUREMENTS

Semiquantitative scoring of cytology smears.

RESULTS

Six of 8 specimens contained carcinoma cells. No contamination by carcinoma cells or normal cells was observed when the working channel was flushed with tap water prior to the sham FNA procedure.

LIMITATIONS

This was an ex vivo study of a limited group of patients.

CONCLUSION

The working channel of the endoscope can be contaminated during the EUS-guided FNA procedure. Cancer cell contamination can be avoided by flushing the endoscope.

Mitral valve surgery for mitral regurgitation caused by Libman-Sacks endocarditis: a report of four cases and a systematic review of the literature

Libman-Sacks endocarditis of the mitral valve was first described by Libman and Sacks in 1924. Currently, the sterile verrucous vegetative lesions seen in Libman-Sacks endocarditis are regarded as a cardiac manifestation of both systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). Although typically mild and asymptomatic, complications of Libman-Sacks endocarditis may include superimposed bacterial endocarditis, thromboembolic events, and severe valvular regurgitation and/or stenosis requiring surgery. In this study we report two cases of mitral valve repair and two cases of mitral valve replacement for mitral regurgitation (MR) caused by Libman-Sacks endocarditis. In addition, we provide a systematic review of the English literature on mitral valve surgery for MR caused by Libman-Sacks endocarditis. This report shows that mitral valve repair is feasible and effective in young patients with relatively stable SLE and/or APS and only localized mitral valve abnormalities caused by Libman-Sacks endocarditis. Both clinical and echocardiographic follow-up after repair show excellent mid- and long-term results.

Hip fracture after radiofrequency ablation therapy for bone tumors: two case reports

Radiofrequency ablation (RFA) has become a valuable therapeutic modality in cancer treatment over the last decade. In orthopedic surgery, RFA is used for the treatment of benign bone tumors and bone metastases. Complications are rare and, to our knowledge, bone fracture as a complication due solely to RFA has not been reported to date. In this report we describe two patients with a fracture in the calcar region of the femur as a complication of RFA treatment for bone malignancies. Since RFA is applied increasingly often, it is important to report this risk of fracture as a complication of treatment of lesions in the femoral calcar.

[18F]FLT-PET and [18F]FDG-PET in the evaluation of radiotherapy for laryngeal cancer

The evaluation of response to radiotherapy in patients with laryngeal cancer is a challenge because of the difficulty to differentiate between post-therapy changes and recurrent or residual tumor. Positron emission tomography is a non-invasive imaging tool that may be helpful in this differentiation. In this study, [(18)F]-fluoro-3'-deoxy-L-thymidine ([(18)F]FLT), a proliferation tracer is compared with 2-[(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]FDG). Patients with primary laryngeal cancer, scheduled to undergo radiotherapy were included in this study. Patients underwent both [(18)F]FLT-PET and [(18)F]FDG-PET shortly before radiotherapy. Ten patients underwent [(18)F]FLT-PET and [(18)F]FDG-PET 2-3 months after radiotherapy. Scans were analyzed visually for areas of increased tracer uptake. The standardized uptake value (SUV) was measured as a semi-quantitative value of tracer uptake. Fourteen patients, all male, were included in this study. Both [(18)F]FLT-PET and [(18)F]FDG-PET showed increased tracer uptake in 12 out of 14 patients (86%). [(18)F]FDG uptake was significantly higher than [(18)F]FLT uptake (SUV(max): 4.5 vs. 2.4 (P=0.002); SUV(mean): 3.4 vs. 1.9 (P=0.002)). After radiotherapy, 3 patients had histologically proven residual or recurrent laryngeal cancer. [(18)F]FDG was true positive in 2 out of 3 patients, whereas [(18)F]FLT showed increased tracer uptake in only one. Of the remaining 7 patients, [(18)F]FLT was true negative in all, whereas [(18)F]FDG showed increased uptake in one (false positive). [(18)F]FLT-PET is feasible in visualizing laryngeal cancer and its evaluation of treatment. The overall uptake of this tracer is significantly lower as compared with [(18)F]FDG, but tumor to background ratios are comparable.

Desmoglein-2 and desmocollin-2 mutations in dutch arrhythmogenic right ventricular dysplasia/cardiomypathy patients: results from a multicenter study

BACKGROUND

This study aimed to evaluate the prevalence and type of mutations in the major desmosomal genes, Plakophilin-2 (PKP2), Desmoglein-2 (DSG2), and Desmocollin-2 (DSC2), in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients. We also aimed to distinguish relevant clinical and ECG parameters.

METHODS AND RESULTS

Clinical evaluation was performed according to the Task Force Criteria (TFC). We analyzed the genes in (a) 57 patients who fulfilled the ARVD/C TFC (TFC+), (b) 28 patients with probable ARVD/C (1 major and 1 minor, or 3 minor criteria), and (c) 31 patients with 2 minor or 1 major criteria. In the TFC+ ARVD/C group, 23 patients (40%) had PKP2 mutations, 4 (7%) had DSG2 mutations, and 1 patient (2%) carried a mutation in DSC2, whereas 1 patient (2%) had a mutation in both DSG2 and DSC2. Among the DSG2 and DSC2 mutation-positive TFC+ ARVD/C probands, 2 carried compound heterozygous mutations and 1 had digenic mutations. In probable ARVD/C patients and those with 2 minor or 1 major criteria for ARVD/C, mutations were less frequent and they were all heterozygous. Negative T waves in the precordial leads were observed more (P<0.002) among mutation carriers than noncarriers and in particular in PKP2 mutation carriers.

CONCLUSIONS

Mutations in DSG2 and DSC2 are together less prevalent (10%) than PKP2 mutations (40%) in Dutch TFC+ ARVD/C patients. Interestingly, biallelic or digenic DSC2 and/or DSG2 mutations are frequently identified in TFC+ ARVD/C patients, suggesting that a single mutation is less likely to cause a full-blown ARVD/C phenotype. Negative T waves on ECG were prevalent among mutation carriers (P<0.002).

The insulin-like growth factor system and sarcomas

Sarcomas are a diverse group of malignant mesenchymal tumours arising from bone and soft tissues. The identification of critical cellular signalling pathways in sarcomas is an important issue for the development of new targeted therapies. This review highlights the experimental and clinical evidence supporting the role of the insulin-like growth factor (IGF) signalling system in the cellular transformation and progression of several types of sarcoma, including rhabdomyosarcoma, synovial sarcoma, leiomyosarcoma, Ewing's sarcoma and osteosarcoma. Preclinical data suggest that the IGF system could be a promising target for therapy in these sarcomas. Currently, therapies interrupting IGF signalling have been or are being developed. In recent phase 1 clinical studies with humanized monoclonal antibodies directed against IGF receptor type 1 (IGF-1R), objective tumour responses were observed in several patients with Ewing's sarcoma, encouraging further clinical testing in Ewing's sarcoma and other sarcoma (sub)types. Moreover, the occasional occurrence of paraneoplastic hypoglycaemia as a result of the secretion of incompletely processed forms of pro-IGF-II by sarcomas is discussed.

Insulin-like growth factors and insulin-like growth factor-binding proteins in relation to disease status and incidence of hypoglycaemia in patients with a gastrointestinal stromal tumour

OBJECTIVE

Patients with a gastrointestinal stromal tumour (GIST) suffering from non-islet cell tumour-induced hypoglycaemia (NICTH), being associated with increased plasma levels of pro-insulin-like growth factor (IGF)-IIE[68-88], have been reported occasionally. We studied the clinical relevance of pro-IGF-IIE[68-88] and other IGF-related proteins in GIST patients.

PATIENTS AND METHODS

Twenty-four patients were included. Plasma samples were collected before 1 week and median 5 months after start of treatment with imatinib, and levels of IGF-I, total IGF-II, pro-IGF-IIE[68-88], insulin-like growth factor-binding protein (IGFBP)-2, -3 and -6 were determined. GIST specimens from 17 patients and tumour cyst fluid from two patients were analysed for IGF-II and IGFBP-2.

RESULTS

Before treatment and/or during follow-up, 3 of 24 (13%) patients showed increased plasma levels of pro-IGF-IIE[68-88]. All three developed NICTH. Overall, patients with metastatic disease, elevated serum lactate dehydrogenase activity or total tumour size >12 cm had the highest pro-IGF-IIE[68-88] levels. Most patients had increased plasma IGFBP-2 levels and these levels were significantly higher in patients with progressive disease. (Pro-)IGF-II was expressed in 82% of GISTs and IGFBP-2 only in one case.

CONCLUSION

We identified pro-IGF-IIE[68-88] as a marker that may be used in the surveillance of GIST.

Incidence and clinical consequences of distal embolization on the coronary angiogram after percutaneous coronary intervention for ST-elevation myocardial infarction

AIMS

We investigated the incidence and sequelae of angiographically visible distal embolization (AVDE) after primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction patients treated with aspirin, heparin, clopidogrel, and glycoprotein-IIb/IIIa inhibitors.

METHODS AND RESULTS

As part of TAPAS, AVDE was a predefined secondary endpoint. We compared angiographic and clinical characteristics, and outcomes of patients with and without AVDE after PCI. AVDE was present on 6.3% of 883 post-procedural angiograms. Angiographically visible distal embolization was associated with significantly worse outcomes, as expressed by lower myocardial blush grade, impaired ST-segment resolution, and higher enzyme levels (all P </= 0.001). Mortality 1 year after PCI was 4 of 56 (7.1%) in patients with AVDE and 43 of 827 (5.2%) in patients without AVDE (P= ns), re-infarction occurred in 5 of 56 (8.9%), and 25 of 827 (3.0%) patients (P = 0.018). The thrombus aspirate more often contained erythrocytes in patients with AVDE than in patients without AVDE (50.0% vs. 15.7%, P < 0.001), and the size of the aspirated thrombus was larger in patients with AVDE (P = 0.002).

CONCLUSION

In patients with triple anti-platelet therapy, the incidence of AVDE after PCI is low, compared with previous reports. Nevertheless, AVDE is associated with impaired myocardial reperfusion and poor outcome. Thrombus composition and size are related to AVDE after PCI.

Abundant Fas expression by gastrointestinal stromal tumours may serve as a therapeutic target for MegaFasL

Although the tyrosine kinase inhibitor imatinib has been shown to be an active agent in patients with gastrointestinal stromal tumours (GIST), complete remissions are almost never seen and most patients finally experience disease progression during their course of treatment. An alternative therapeutic option is to target death receptors such as Fas. We showed that a panel of imatinib-sensitive (GIST882) and imatinib-resistant (GIST48, GIST430 and GIST430K-) cell lines expressed Fas. MegaFasL, a recently developed hexameric form of soluble Fas ligand (FasL), appeared to be an active apoptosis-inducing agent in these cell lines. Moreover, MegaFasL potentiated the apoptotic effects of imatinib. Immunohistochemical evaluations, in 45 primary GISTs, underscored the relevance of the Fas pathway: Fas was expressed in all GISTs and was expressed strongly in 93%, whereas FasL was expressed at moderate and strong levels in 35 and 53% of GISTs, respectively. Fas and FasL expression were positively correlated in these primary GISTs, but there was no association between Fas or FasL expression and primary site, histological subtype, tumour size, mitotic index, risk classification, and KIT mutation status. The abundant immunohistochemical Fas and FasL expression were corroborated by western blot analysis. In conclusion, our data implicate Fas as a potential therapeutic target in GIST.