Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment

In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [(18)F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg(-1)) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover, longitudinal PET allows non-invasive assessment of individual plaque-load kinetics, thereby accommodating inter-animal variations.

Endothelial microparticles reduce ICAM-1 expression in a microRNA-222-dependent mechanism

Endothelial microparticles (EMP) are released from activated or apoptotic endothelial cells (ECs) and can be taken up by adjacent ECs, but their effect on vascular inflammation after engulfment is largely unknown. We sought to determine the role of EMP in EC inflammation. In vitro, EMP treatment significantly reduced tumour necrosis factor-α-induced endothelial intercellular adhesion molecule (ICAM)-1 expression on mRNA and protein level, whereas there was no effect on vascular cell adhesion molecule-1 expression. Reduced ICAM-1 expression after EMP treatment resulted in diminished monocyte adhesion in vitro. In vivo, systemic treatment of ApoE−/− mice with EMP significantly reduced murine endothelial ICAM-1 expression. To explore the underlying mechanisms, Taqman microRNA array was performed and microRNA (miR)-222 was identified as the strongest regulated miR between EMP and ECs. Following experiments demonstrated that miR-222 was transported into recipient ECs by EMP and functionally regulated expression of its target protein ICAM-1 in vitro and in vivo. After simulating diabetic conditions, EMP derived from glucose-treated ECs contained significantly lower amounts of miR-222 and showed reduced anti-inflammatory capacity in vitro and in vivo. Finally, circulating miR-222 level was diminished in patients with coronary artery disease (CAD) compared to patients without CAD. EMPs promote anti-inflammatory effects in vitro and in vivo by reducing endothelial ICAM-1 expression via the transfer of functional miR-222 into recipient cells. In pathological hyperglycaemic conditions, EMP-mediated miR-222-dependent anti-inflammatory effects are reduced.

Surgical staging and prognosis in serous borderline ovarian tumours (BOT): a subanalysis of the AGO ROBOT study

BACKGROUND

Incomplete surgical staging is a negative prognostic factor for patients with borderline ovarian tumours (BOT). However, little is known about the prognostic impact of each individual staging procedure.

METHODS

Clinical parameters of 950 patients with BOT (confirmed by central reference pathology) treated between 1998 and 2008 at 24 German AGO centres were analysed. In 559 patients with serous BOT and adequate ovarian surgery, further recommended staging procedures (omentectomy, peritoneal biopsies, cytology) were evaluated applying Cox regression models with respect to progression-free survival (PFS).

RESULTS

For patients with one missing staging procedure, the hazard ratio (HR) for recurrence was 1.25 (95%-CI 0.66-2.39; P=0.497). This risk increased with each additional procedure skipped reaching statistical significance in case of two (HR 1.95; 95%-CI 1.06-3.58; P=0.031) and three missing steps (HR 2.37; 95%-CI 1.22-4.64; P=0.011). The most crucial procedure was omentectomy which retained a statistically significant impact on PFS in multiple analysis (HR 1.91; 95%-CI 1.15-3.19; P=0.013) adjusting for previously established prognostic factors as FIGO stage, tumour residuals, and fertility preservation.

CONCLUSION

Individual surgical staging procedures contribute to the prognosis for patients with serous BOT. In this analysis, recurrence risk increased with each skipped surgical step. This should be considered when re-staging procedures following incomplete primary surgery are discussed.

MicroRNA expression in circulating microvesicles predicts cardiovascular events in patients with coronary artery disease

Background

Circulating microRNAs (miRNAs) are differentially regulated and selectively packaged in microvesicles (MVs). We evaluated whether circulating vascular and endothelial miRNAs in patients with stable coronary artery disease have prognostic value for the occurrence of cardiovascular (CV) events.

Methods and Results

Ten miRNAs involved in the regulation of vascular performance—miR‐126, miR‐222, miR‐let7d, miR‐21, miR‐20a, miR‐27a, miR‐92a, miR‐17, miR‐130, and miR‐199a—were quantified in plasma and circulating MVs by reverse transcription polymerase chain reaction in 181 patients with stable coronary artery disease. The median duration of follow‐up for major adverse CV event–free survival was 6.1 years (range: 6.0–6.4 years). Events occurred in 55 patients (31.3%). There was no significant association between CV events and plasma level of the selected miRNAs. In contrast, increased expression of miR‐126 and miR‐199a in circulating MVs was significantly associated with a lower major adverse CV event rate. In univariate analysis, above‐median levels of miR‐126 in circulating MVs were predictors of major adverse CV event–free survival (hazard ratio: 0.485 [95% CI: 0.278 to 0.846]; P=0.007) and percutaneous coronary interventions (hazard ratio: 0.458 [95% CI: 0.222 to 0.945]; P=0.03). Likewise, an increased level of miR‐199a in circulating MVs was associated with a reduced risk of major adverse CV events (hazard ratio: 0.518 [95% CI: 0.299 to 0.898]; P=0.01) and revascularization (hazard ratio: 0.439 [95% CI: 0.232 to 0.832]; P=0.01) in univariate analysis. miRNA expression analysis in plasma compartments revealed that miR‐126 and miR‐199a are present mainly in circulating MVs. MV‐sorting experiments showed that endothelial cells and platelets were found to be the major cell sources of MVs containing miR‐126 and miR‐199a, respectively.

Conclusion

MVs containing miR‐126 and miR‐199a but not freely circulating miRNA expression predict the occurrence of CV events in patients with stable coronary artery disease.

Age-dependent differences in borderline ovarian tumours (BOT) regarding clinical characteristics and outcome: results from a sub-analysis of the Arbeitsgemeinschaft Gynaekologische Onkologie (AGO) ROBOT study

BACKGROUND

Approximately one-third of all borderline ovarian tumours (BOT) are diagnosed in patients with child-bearing potential. Detailed information regarding their specific characteristics and prognostic factors is limited.

METHODS

Clinical parameters of BOT patients treated between 1998 and 2008 in 24 German centres were retrospectively investigated. Central pathology review and prospective follow-up were carried out. Patients <40 versus ≥40 years were analysed separately and then compared regarding clinico-pathological variables and prognosis.

RESULTS

A total of 950 BOT patients with a median age of 49.1 (14.1-91.5) years were analysed [280 patients <40 years (29.5%), 670 patients ≥40 years (70.5%)]. Fertility-preserving surgery was carried out in 53.2% (149 of 280) of patients <40 years with preservation of the primarily affected ovary in 32 of these 149 cases (21.5%). Recurrence was significantly more frequent in patients <40 years (19.0% versus 10.1% 5-year recurrence rate, P < 0.001), usually in ovarian tissue, whereas disease-specific overall survival did not differ between the subgroups. In case of recurrent disease, malignant transformation was less frequent in younger than in older patients (12.0% versus 66.7%, P < 0.001), mostly presenting as invasive peritoneal carcinomatosis. Multivariate analysis for patients <40 years identified advanced International Federation of Gynecology and Obstetrics (FIGO) stage and fertility-sparing approach as independent prognostic factors negatively affecting progression-free survival (PFS) while, for patients ≥40 years, higher FIGO stage and incomplete staging was associated with impaired PFS.

CONCLUSIONS

Despite favourable survival, young BOT patients with child-bearing potential are at higher risk for disease recurrence. However, relapses usually remain BOT in the preserved ovaries as opposed to older patients being at higher risk for malignant transformation in peritoneal or distant localisation. Therefore, fertility-sparing approach can be justified for younger patients after thorough consultation.

Abstract P2-18-14: MarginProbe® - Final results of the German post-market study in breast conserving surgery of ductal carcinoma in situ

Background: Surgical margins in breast conserving surgery (BCS) of ductal carcinoma in situ (DCIS) as well as invasive cancer are a subject of intense discussion. A positive margin is still one of the strongest predictor for risk of local recurrence of intraductal and invasive breast cancer. Intraoperative margin assessment of DCIS is difficult and existing options are unsatisfying.

Aim of our study was to evaluate the performance of MarginProbe®(Dune Medical Devices, Boston, MA, USA) in assessing surgical margins for DCIS and the contribution to lowering the re-excision rate after initial BCS.

Material and methods: The device includes a disposable hand-held probe and a console, is based on radiofrequency spectroscopy, and detects differences in dielectric properties between normal and malignant breast tissue.

The multicentre single arm, post market study was performed on 55 patients at 3 German sites under approval of institutional review boards. MarginProbe® was used as an adjunctive tool to the current practice. All specimens were sent for paraffin embedded pathological analysis.

The procedure success was defined as both: negative margins after initial BCS; and early identification of an extended lesion, with conversion to mastectomy instead of performing a re-excision BCS.

Results: From September 2009 - May 2010, 42/55 patients were eligible for this analysis. In comparison with a historical re-excision rate of 39% for DCIS patients undergoing BCS, use of MarginProbe® led to a reduction of the re-excision rate by 56%, down to 17% (p = 0.018) (surgical margin width of 5 mm). The procedure success was also significantly improved by more than 3-fold (p&lt;0.0001), from 14% (6/42) by standard of care (SOC) alone, to 57% (24/42) with use of the device. In 21% (9/42) of the cases use of the device led to a direct conversion to mastectomy due to extensive disease identified, sparing an additional re-excision BCS. Resected average main specimen tissue volume was 34.6 cc. Tissue volume associated with false positive margins was, on average, 7.5 cc per patient. Cosmetic outcomes were not different.

Discussion: In synopsis with the other two clinical trials (MAST and US pivotal study) we found our data consistent. Each trial reported a reduction of the re-resection rate by more than 50%.

Our results demonstrate that adjunctive use of the device is effective in achieving procedure success and reducing re-excisions for DCIS patients. Several options for intraoperative margin assessment exist, but for DCIS they are time-consuming and insufficient (frozen section, touch prep cytology) or experimental (near-infrared fluorescence optical imaging, high-frequency ultrasound). Usually, the pathologist provides final analysis of the lesion extension and margin assessment several days after operation.

Conclusion: MarginProbe® is a device that provides a fast and effective technique for intraoperative margin assessment that is already used in daily routine. It lowers the re-excision rate for both DCIS and invasive cancer significantly, by &gt;50%, without any influence on patient's cosmesis. It may allow the surgeon to perform oncoplastic or reconstructive breast surgery and IORT more safely in the future.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-18-14.