Treatment-related changes in neurobehavioral symptoms

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Background: Neurobehavioral outcomes, such as fatigue and neurocognitive dysfunction, are disabling side effects in a subgroup of breast cancer (BC) patients. Longitudinal studies with appropriate controls to dissociate treatment-related effects from those experienced by healthy post-menopausal women are sparse, and virtually all define “pre-treatment” baseline as prior to adjuvant therapy, but following surgery. Given the phenomenon of “postoperative cognitive dysfunction” reported in older patients undergoing major surgery, we are evaluating treatment-related impact using pre-surgery assessment as the baseline.

Methods: Eligible post-menopausal BC patients are assessed prior to any local or systemic treatment and one month after completion of treatment (surgery, radiation and/or chemotherapy). Healthy controls (HC) are age-matched 1:2-3 and tested at similar time intervals. Currently 130 BC and 60 HC are enrolled; results for 80 BC and 30 HC who have reached Time 2 are available (Mean time between assessments = 143 days, SD = 93).

Results: Interim analyses using repeated measures ANOVA, controlling for age and education differences, show that the BC group declined in verbal memory functioning post-treatment relative to baseline, while the HC group improved due to practice effects (F(1, 102) = 3.43, p = .061). A similar interaction effect is observed for executive functioning, where the BC group failed to benefit from practice effects to the same degree as did HC (F(1, 102) = 6.04, p = .016). Anxiety but not depression was significantly elevated at baseline and decreased post treatment in BC patients treated with and without chemotherapy (F (1, 102) = 6.85, p = .010). Fatigue did not significantly change for the BC group; however, it was significantly higher than HC at baseline (t =2.77, p = .01) and remained high at the post-treatment measurement.

Conclusions: Significant declines in neurocognitive functioning soon after completion of BC treatment were observed compared to healthy post-menopausal women. This observation did not appear to be due to mood disturbance, as anxiety and depression decreased following treatment. Our data also suggest that fatigue is present even prior to any cancer treatment.

Prognostic significance of histopathological parameters in sentinel nodes of melanoma patients

AIMS

The presence of micrometastases in the sentinel lymph node (SLN) is an important prognostic parameter for melanoma patients. The aim was to determine the prognostic relevance of histopathological characteristics of micrometastases in the SLN, which has not been adequately addressed thus far.

METHODS AND RESULTS

In 169 melanoma patients with positive SLN, histopathological features of the SLN were correlated with overall survival (OS) and relapse-free survival (RFS). Tumour burden, expansion of melanoma cells in the periphery (infiltration of capsule) and towards the centre of the SLN [tumour penetrative depth (TPN)] were of prognostic significance for OS and RFS on univariate analysis. Multivariate analysis revealed three independent significant parameters which predict a poor prognosis: presence of infiltration of the SLN capsule, TPN > or = 2 mm and size of the largest tumour deposit > or = 30 cells.

CONCLUSIONS

Histopathological analysis of SLN allows the identification of patients with a poor prognosis depending on the location of melanoma cells and tumour burden.

The proteasome inhibitor bortezomib acts differently in combination with p53 gene transfer or cytotoxic chemotherapy on NSCLC cells

In this report, the effects of a combined treatment with the proteasome inhibitor bortezomib and either a recombinant adeno-associated virus type 2 (rAAV-2)-mediated p53 gene transfer or chemotherapeutic agents, docetaxel and pemetrexed, were tested on p53 positive and p53negative non-small cell lung cancer (NSCLC) cell lines. The combination of bortezomib and rAAV-p53 led to a significant synergistic inhibition of cell growth between 62-82% depending on the p53 status of the cell line and drug concentration. Surviving cells of the combined treatment showed a significant reduced ability to form colonies. Enhanced cell toxicity was associated with a 5.3-14.4-fold increase of the apoptotic rate and intracellular p53 level up to 50.4% following vector-mediated p53 restoration and bortezomib treatment. In contrast, an antagonistic effect on tumor cell growth and colony formation was observed for the combination of bortezomib and docetaxel or pemetrexed as a reduction of cell growth between 31 and 48% was found in comparison to 50% using the single agents. Lower cytotoxic effects were associated with significantly reduced apoptosis and an increase of clonogenic growth. The observed antagonistic effects between bortezomib and docetaxel or pemetrexed might influence clinical trials using these compounds. Conversely, p53 restoration and bortezomib treatment led to enhanced, synergistic tumor cell toxicity.

Evaluation of oxidative stress measurements in obstructive sleep apnea syndrome

Assessment of reactive oxygen species (ROS) is highly important in neurodegenerative disorders and neuroleptic treatment. However, conflicting results have been reported, which may arise from methodological difficulties. Obstructive sleep apnea (OSA) syndrome with episodic hypoxia-reoxygenation is proposed as a human model for the investigation of ROS measurements. Despite a broad analytical approach comprising lipid peroxidation and amino acid oxidation products, oxidative DNA damage, and activity of the antioxidant defense, only plasma malondialdehyde (MDA) and urinary o,o'-dityrosine seemed to be appropriate, robust biomarkers of oxidative stress, which are also simple enough for routine clinical use. MDA concentrations correlated with a duration of nocturnal desaturation below 85% (r = 0.77, p<0.0005), and o,o'-dityrosine levels decreased after therapy (p<0.05) as a function of baseline concentrations (r = -0.61, p<0.05). Gender effects in ROS generation also have to be considered. At present, we recommend the application of several oxidative stress measurements at different time points, preferably involving plasma MDA and urinary o,o'-dityrosine.

Electrooptic modulation up to 40 GHz in a barium titanate thin film waveguide modulator

The high frequency operation of a low-voltage electrooptic modulator based on a strip-loaded BaTiO3 thin film waveguide structure has been demonstrated. The epitaxial BaTiO3 thin film on an MgO substrate forms a composite structure with a low effective dielectric constant of 20.8 at 40 GHz. A 3.9 V half-wave voltage with a 3.7 GHz 3-dB bandwidth and a 150 pm/V effective electrooptic coefficient is obtained for the 3.2mm-long modulator at 1.55 ?m. Broadband modulation up to 40 GHz is measured with a calibrated detection system. Numerical simulations indicate that the BaTiO3 thin film modulator has the potential for a 3-dB operational bandwidth in excess of 40 GHz through optimized design.