Structural dynamics associated with intermediate formation in an archetypal conformational disease

In conformational diseases, native protein conformers convert to pathological intermediates that polymerize. Structural characterization of these key intermediates is challenging. They are unstable and minimally populated in dynamic equilibria that may be perturbed by many analytical techniques. We have characterized a forme fruste deficiency variant of α₁-antitrypsin (Lys154Asn) that forms polymers recapitulating the conformer-specific neo-epitope observed in polymers that form in vivo. Lys154Asn α₁-antitrypsin populates an intermediate ensemble along the polymerization pathway at physiological temperatures. Nuclear magnetic resonance spectroscopy was used to report the structural and dynamic changes associated with this. Our data highlight an interaction network likely to regulate conformational change and do not support the recent contention that the disease-relevant intermediate is substantially unfolded. Conformational disease intermediates may best be defined using powerful but minimally perturbing techniques, mild disease mutants, and physiological conditions.

The addition of bevacizumab to temozolomide and radiation therapy followed by bevacizumab, temozolomide, and oral topotecan for newly diagnosed glioblastoma multiforme (GBM)

2090^

Background: The prognosis for newly-diagnosed GBM is dismal. The addition of temozolomide to radiation therapy improved the median overall survival (OS) to 14.6 months (mos). GBM’s have the highest levels of vascular endothelial growth factor (VEGF). Hypoxia inducing factor-1 alpha (HIF-1 alpha) is an important regulator of VEGF, and topotecan may inhibit HIF-1 alpha. Methods: We performed a phase II trial in newly diagnosed GBM by adding bevacizumab and topotecan to standard therapy. 80 newly diagnosed GBM patients were enrolled between January 2010 and January 2011. Patients received standard radiation therapy and temozolomide. Bevacizumab at 10 mg/kg every 14 days was added a minimum of 4 weeks post-op. Two weeks after radiation therapy was completed, 12 monthly cycles of temozolomide at 150 mg/m2 /d days 1-5, oral topotecan at 1.5 mg/m2 for patients not on an enzyme inducing anti-epileptic drug (EIAED) and 2.0 mg/m2 for patients on an EIAED days 2-6, and bevacizumab at 10 mg/kg on days 1 and 15. Results: The addition of bevacizumab to standard radiation therapy and daily temozolomide was safe. Of the 80 patients, 76 completed radiation therapy. Four patients did not complete radiation, two with clinical decline, one each with a bone flap infection, and a pulmonary embolus. Fifteen patients came off study for toxicity, five with recurrent grade IV thrombocytopenia, three with grade III fatigue, two each with grade 2 CNS hemorrhage, and wound dehiscence requiring surgery and one each with GI perforation, pulmonary embolism and an aortic thrombus. Of the 80 patients, 56 have progressed and 37 have died. The median progression-free survival (PFS) and OS are 11.1 mos (95% CI: 9.4-13.6) and 17.2 mos (95% CI: 15.2) at a median follow-up of 18.4 months. The two year OS is 45.3%. Conclusions: The addition of bevacizumab to temozolomide and radiation followed by temozolomide, bevacizumab and oral topotecan is tolerable. The median PFS and OS are encouraging. The randomized phase III trials with bevacizumab for newly diagnosed GBM patients are essential.

Safety and efficacy of the addition of bevacizumab to temozolomide and radiation therapy followed by bevacizumab, temozolomide, and irinotecan for newly diagnosed glioblastoma multiforme

2094^

Background: Glioblastoma (GBM) has a very poor prognosis, and the majority of patients die within 2 years of diagnosis. GBMs have high concentrations of vascular endothelial growth factor (VEGF), and the more VEGF, the worse the prognosis. Bevacizumab is a humanized antibody to VEGF and is active in recurrent GBMs. The study aims to improve the survival of newly diagnosed GBM patients by incorporating an anti-angiogenic agent with radiation and temozolomide, and adding a topoisomerase I inhibitor, and an anti-angiogenic agent to temozolomide post-radiation therapy. Methods: Patients received standard radiation and temozolomide at 75 mg/m2/day, with bevacizumab at 10 mg/kg every 14 days beginning a minimum of 28 days post-operatively. Following the completion of radiation therapy, patients received 6-12 cycles of bevacizumab, temozolomide and irinotecan. Each cycle was 28 days. Bevacizumab was given at a dose of 10 mg/kg days 1 and 15, temozolomide 200 mg/m2 days 1-5 and irinotecan on days 1 and 15 at 125 mg/m2 for patients not on an enzyme inducing anti-epileptic (EIAED) and 340 mg/m2 for patients on an EIAED. The statistical design was a goal of 60% overall survival at 16 months. Results: 125 patients were enrolled between 8/07 and 3/09. All the patients have completed therapy. Nine patients had thromboembolic complications (DVT or PE). Two patients had wound dehiscence, one bowel perforation, one secondary AML and two pneumocystis carinii pneumonias (PCP). Seventeen had grade 4 hematologic toxicity requiring dose decrements. There were 4 toxic deaths, one each with a myocardial infarction PCP, PE and sepsis. At a median follow-up of 40 mos, the median overall survival was 20.9 mos, the median progression-free survival was 13.8 mos and the 2-year overall survival was 42.4%. Conclusions: Adding bevacizumab to temozolomide and radiation therapy followed by bevacizumab, temozolomide with irinotecan is tolerable and efficacious.

Summary report on the graded prognostic assessment: an accurate and facile diagnosis-specific tool to estimate survival for patients with brain metastases

PURPOSE

Our group has previously published the Graded Prognostic Assessment (GPA), a prognostic index for patients with brain metastases. Updates have been published with refinements to create diagnosis-specific Graded Prognostic Assessment indices. The purpose of this report is to present the updated diagnosis-specific GPA indices in a single, unified, user-friendly report to allow ease of access and use by treating physicians.

METHODS

A multi-institutional retrospective (1985 to 2007) database of 3,940 patients with newly diagnosed brain metastases underwent univariate and multivariate analyses of prognostic factors associated with outcomes by primary site and treatment. Significant prognostic factors were used to define the diagnosis-specific GPA prognostic indices. A GPA of 4.0 correlates with the best prognosis, whereas a GPA of 0.0 corresponds with the worst prognosis.

RESULTS

Significant prognostic factors varied by diagnosis. For lung cancer, prognostic factors were Karnofsky performance score, age, presence of extracranial metastases, and number of brain metastases, confirming the original Lung-GPA. For melanoma and renal cell cancer, prognostic factors were Karnofsky performance score and the number of brain metastases. For breast cancer, prognostic factors were tumor subtype, Karnofsky performance score, and age. For GI cancer, the only prognostic factor was the Karnofsky performance score. The median survival times by GPA score and diagnosis were determined.

CONCLUSION

Prognostic factors for patients with brain metastases vary by diagnosis, and for each diagnosis, a robust separation into different GPA scores was discerned, implying considerable heterogeneity in outcome, even within a single tumor type. In summary, these indices and related worksheet provide an accurate and facile diagnosis-specific tool to estimate survival, potentially select appropriate treatment, and stratify clinical trials for patients with brain metastases.

Micropuncture needles combined with ultrasound guidance for unusual central venous cannulation: desperate times call for desperate measures--a new trick for old anesthesiologists

Central vascular access can be a very challenging task in patients with skeletal deformities such as ankylosing spondylitis, kyphosis, and chin-on-chest deformity. The use of traditional methods of accessing the central venous circulation in these patients can require multiple attempts and may lead to significant complications such as bleeding, pneumothorax, and vascular injury. Ultrasound-guided central venous access has become a very common procedure in the United States and Europe; its efficacy and safety have been demonstrated, and together with the use of micropuncture needles, the technique can facilitate central venous access in complicated cases.

The effect of tumor subtype on survival and the graded prognostic assessment (GPA) for patients with breast cancer and brain metastases

238

Background: The Diagnosis-Specific Graded Prognostic Assessment (DS-GPA) was published to clarify prognosis for patients with brain metastases. This study refines the existing Breast GPA by analyzing a larger cohort and tumor subtype.

Methods: A multi-institutional retrospective database of 400 breast cancer patients treated for newly-diagnosed brain metastases was generated. Prognostic factors significant for survival were analyzed by multivariate Cox regression (MCR) and recursive partitioning analysis (RPA). Factors were weighted by magnitude of their regression coefficients to define the GPA index. A GPA score of 4.0 represents the best prognosis, 0.0, the worst.

Results: Significant prognostic factors by MCR and RPA were Karnofsky Performance Status (KPS), HER2, ER/PR status, and the interaction between ER/PR and HER2. RPA showed age was significant for patients with KPS 60-80. The median survival time (MST) overall was 13.8 months, and for GPA scores of 0-1.0, 1.5-2.0, 2.5-3.0 and 3.5-4.0 was 3.4 (n=23), 7.7 (n=104), 15.1 (n=140) and 25.3 (n=133) months, respectively (p < 0.0001). See table. Among HER2-negative patients, being ER/PR-positive improved MST from 6.4 to 9.7 months whereas in HER2-positive patients, being ER/PR-positive improved MST from 17.9 to 20.7 months. The log-rank statistic (predictive power) was 110 for the Breast-GPA versus 55 for tumor subtype.

Conclusions: The Breast-GPA documents wide variation in prognosis and shows clear separation between subgroups of patients with breast cancer and brain metastases. This tool will aid clinical decision-making and stratification of clinical trials. These data confirm the effect of tumor subtype on survival and show the Breast-GPA offers significantly more predictive power than the tumor subtype alone.

[Table: see text]

Radiation dose-volume effects of optic nerves and chiasm

Publications relating radiation toxicity of the optic nerves and chiasm to quantitative dose and dose-volume measures were reviewed. Few studies have adequate data for dose-volume outcome modeling. The risk of toxicity increased markedly at doses >60 Gy at approximately 1.8 Gy/fraction and at >12 Gy for single-fraction radiosurgery. The evidence is strong that radiation tolerance is increased with a reduction in the dose per fraction. Models of threshold tolerance were examined.

Diagnosis-specific prognostic factors, indexes, and treatment outcomes for patients with newly diagnosed brain metastases: a multi-institutional analysis of 4,259 patients

PURPOSE

Controversy endures regarding the optimal treatment of patients with brain metastases (BMs). Debate persists, despite many randomized trials, perhaps because BM patients are a heterogeneous population. The purpose of the present study was to identify significant diagnosis-specific prognostic factors and indexes (Diagnosis-Specific Graded Prognostic Assessment [DS-GPA]).

METHODS AND MATERIALS

A retrospective database of 5,067 patients treated for BMs between 1985 and 2007 was generated from 11 institutions. After exclusion of the patients with recurrent BMs or incomplete data, 4,259 patients with newly diagnosed BMs remained eligible for analysis. Univariate and multivariate analyses of the prognostic factors and outcomes by primary site and treatment were performed. The significant prognostic factors were determined and used to define the DS-GPA prognostic indexes. The DS-GPA scores were calculated and correlated with the outcomes, stratified by diagnosis and treatment.

RESULTS

The significant prognostic factors varied by diagnosis. For non-small-cell lung cancer and small-cell lung cancer, the significant prognostic factors were Karnofsky performance status, age, presence of extracranial metastases, and number of BMs, confirming the original GPA for these diagnoses. For melanoma and renal cell cancer, the significant prognostic factors were Karnofsky performance status and the number of BMs. For breast and gastrointestinal cancer, the only significant prognostic factor was the Karnofsky performance status. Two new DS-GPA indexes were thus designed for breast/gastrointestinal cancer and melanoma/renal cell carcinoma. The median survival by GPA score, diagnosis, and treatment were determined.

CONCLUSION

The prognostic factors for BM patients varied by diagnosis. The original GPA was confirmed for non-small-cell lung cancer and small-cell lung cancer. New DS-GPA indexes were determined for other histologic types and correlated with the outcome, and statistical separation between the groups was confirmed. These data should be considered in the design of future randomized trials and in clinical decision-making.