Retrospective analysis of clinico-pathological features and outcomes of 2,686 hormone receptors-positive breast cancer (HR+) patients in a consecutive mono-institutional series

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Background: Clinico-pathological patterns, management and outcomes of HR+ vs HR- have been evaluated in a retrospective study. Methods: A series of 2686 BC patients (pts), treated at our institution from 1988 to 2000 with known immunohistochemical receptor status was investigated. Correlation between HR status and tumour size (T), nodal status (N), grading (G), mib-1, HER-2 and p53 and was evaluated by χ square test. Statistical analysis was performed to test the interaction between HR status and Disease Free Survival (DFS) and with specific and overall survival, using the log-rank test. Results: Among 2686 patients, 467 HR- (17%) and 2219 (83%) HR+ (364 pre and 1855 postmenopausal) were observed, with 1586 ER+PgR+, 555 ER+PgR-, 78 ER-PgR+. Pts with positive HR status showed a statistically significant correlation with lower T, G, mib-1, HER-2 and p53 expression.Chemotherapy was administered to 681 HR+BC (31% ) and to 301 HR-BC (65%), according to stage, age, and G. Tamoxifen based endocrine therapy was administered to 1167 HR+BC (53%) (associated to chemotherapy in 428 and alone in 739 pts). At a median follow up of 108 months, 499 relapses occurred in HR+ (22%) , and 141 in HR- pts (30%), with a 5,10, 15y DFS of 83%,72%, 62% in HR+ and 72%,66%, 57% respectively in HR- pts. More frequent sites of relapse were soft tissue (46%) and bone (35%) in HR+ and soft tissue (50%) and visceral (30%) in HR- pts. Seven hundred sixty pts have died: 576 HR+ (26%) and 184 HR- (39%), with a 5, 10, 15y specific survival of 90%, 84%, 75% which was significantly superior to the 78%, 73%, 69% respectively of HR-. However, considering that 230 HR+ and 44 HR- pts died without relapse, the 5,10,15y overall survival was 90%, 75% 61% for HR+ and 78%, 67%, 60% respectively for HR-. It appears therefore that the specific survival advantage in early years in favour of HR+ is progressively reduced by non specific mortality in late years which results in similar 15 y OS rates among HR+ and HR- pts. Conclusions: Our series appear to confirm the relationship between HR+ status and other more favourable clinical-pathological features, although long term OS is not apparently affected.

No significant financial relationships to disclose.

Clinical presentation and outcomes of 2,924 early breast cancer patients (br.ca. pts) treated in a single institution in a 10-year period with a long follow up

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Background: A consecutive series of br.ca. pts, treated between Jan 1st 1990 to Dec 31st 1999 in our Department, is the basis of our retrospective study, aimed to create a data base on routinary clinical management of early br.ca. pts, to which compare similar series and literature data. Methods: All Clinical Records were reviewed and computerized. Disease free and overall survival were estimated using the product-limit method of Kaplan and Meier. The log-rank test was used to compare prognosis between different subgroups. Results: Among 2924 consecutive br.ca. pts, 836 were younger than 50 years (med. age 44) and 2088 older (med. age 63). Regional nodes were negative (N−) in 1754, positive (N+) in 1027 and unknown in the remaining pts. So, 2593 pts were stage I-II and 301 stage IIIA-B. Hormonal Receptor status (available on 2560 pts) was positive for Estrogen (ER+) in 2021 pts and for Progesterone (PgR+) in 1649 pts. Moreover, 1571 pts were ER+Pgr+, 539 ER-PgR−, 78 ER-PgR+ and 461 ER+PgR−. HER2 was overexpressed in 262/1426 (18%) pts. Tumor grading (available on 2176 cases) was G1–2 in 1411 and G3–4 in 765 cases. After surgery, 731 pts received adjuvant Tamoxifen, 507 pts CMF ± Antracyclines chemotherapy, 434 pts both chemotherapy and Tamoxifen and 958 pts none. (no therapy data are available for the remaining 334 pts). At a median f.up of 9.8 years, 993/2924 pts (33.9%) have recurred, (med. DFS 137 mos) with a 5, 10 and 15 y probability of recurrence of 26, 44 and 63% respectively. Corresponding figures of recurrence for N− pts were 14, 30 and 50% (med. DFS 168 mos), while for N+ pts were 41, 61 and 77% (med DFS 81 mos). For younger N+ pts treated with chemotherapy, the 5 years probability of recurrence was 34% while it was 24% for older ER+ pts treated with hormonal therapy. So far, 794/2924 (27.5%) pts have died, with a 5, 10 and 15 y probability of death of 13, 27 and 41%. This was 5, 16 and 28% for N- pts and 22, 41 and 56% for N+ pts. For younger N+ pts treated with chemotherapy, the 5 y probability of death was 14%, as it was for older ER+ pts treated with Tamoxifen. Conclusions: Although this data are not yet conclusive, it appears that large part of the clinical improvements reported in clinical trials may be achieved in the routine management of breast cancer pts.

No significant financial relationships to disclose.

A model-based study of passive joint properties on muscle effort during static stance

This study examined the impact of lower extremity joint stiffnesses and simulated joint contractures on the muscle effort required to maintain static standing postures after a spinal cord injury (SCI). Static inverse computer simulations were performed with a three-dimensional 15 degree of freedom musculoskeletal model placed in 1600 different standing postures. The required lower extremity muscle forces were calculated through an optimization routine that minimized the sum of the muscle stresses squared, which was used as an index of the muscle effort required for each standing posture. Joint stiffnesses were increased and decreased by 100 percent of their nominal values, and contractures were simulated to determine their effects on the muscle effort for each posture. Nominal muscle and passive properties for an individual with a SCI determined the baseline muscle effort for comparisons. Stiffness changes for the ankle plantar flexion/dorsiflexion, hip flexion/extension, and hip abduction/adduction directions had the largest effect on reducing muscle effort by more than 5 percent, while changes in ankle inversion/eversion and knee flexion/extension had the least effect. For erect standing, muscle effort was reduced by more than 5 percent when stiffness was decreased at the ankle plantar flexion/dorsiflexion joint or hip flexion/extension joint. With simulated joint contractures, the postural workspace area decreased and muscle effort was not reduced by more than 5 percent for any posture. Using this knowledge, methods can be developed through the use of orthoses, physical therapy, surgery or other means to appropriately augment or diminish these passive moments during standing with a neuroprosthesis.

Pressure-induced formation of diblock copolymer "micelles" in supercritical fluids. A combined study by small angle scattering experiments and mean-field theory. II. Kinetics of the unimer-aggregate transition

We developed a simple time-dependent mean-field theory to describe the phase separation kinetics of either homopolymers or AB-diblock copolymers in supercritical (SC) fluids. The model, previously used to describe the phase behavior of AB-block copolymers under the assumption of strong solvent selectivity for just one copolymer chain, has been extended to study the kinetics of the phase separation process. Time resolved small angle x-ray scattering (TR-SAXS) measurements have been performed on different AB-diblock copolymers containing a perfluorinated chain and dissolved in SC-CO2. The data obtained over a wide range of pressure and temperature confirm our theoretical predictions. Particularly interesting is the presence of two relaxation frequencies for the homogeneous solution --> spherical aggregate transition, where the two relaxation processes depend on the depth of the pressure jump and on temperature. The whole phenomenon could be explained as an initial SC solvent/polymer phase separation followed by a slow reorientation process to form spherical aggregates driven by the copolymer solvophilic moiety.

Pressure-induced formation of diblock copolymer “micelles” in supercritical fluids. A combined study by small angle scattering experiments and mean-field theory. I. The critical micellization density concept

We developed a simple mean-field theory to describe polymer and AB diblock copolymer phase separation in supercritical (SC) fluids. The highly compressible SC fluid has been described by using a phenomenological hole theory, properly extended to consider the solvent/polymer/vacancy pseudoternary mixture. The model has been applied to describe the phase behavior of AB-diblock copolymers under the assumption of a strong solvent selectivity for just one copolymer chain. In our model the solvent selectivity is a strong function of the external pressure because in compressible fluids vacancies reduce the number of favorable solvent-polymer contacts. The combined effect of the pressure on the average solvent quality and selectivity for a single polymer chain makes the phase behavior of a diblock copolymer in SC fluids quite complex. Small angle neutron and x-ray scattering (SANS and SAXS) measurements have been performed on SC-CO2 solutions of different AB-diblock copolymers containing a perfluorinated chain. The data obtained over a wide range of pressure and temperature confirm our theoretical predictions.

SAXS investigation on aggregation phenomena in supercritical CO2

Synchrotron Small-Angle X-Ray scattering (SAXS) measurements on aggregate formation of a Polyvinyl acetate- b-Perfluoro octyl acrylate (PVAc- b-PFOA) block copolymer in supercritical CO(2) are here reported. Experiments were carried out for a series of different thermodynamic conditions, changing the solvent density by profiling both the pressure at constant temperature and the temperature at constant pressure. This block copolymer and in general fluorocarbon-hydrocarbon di-blocks form aggregates depending on the value of CO(2) density. A sharp transition between monomers dissolved as random coils and micelles characterized by a solvophilic shell and a solvophobic core occurs when the CO(2) density reaches a critical value. Results of critical micellization density (CMD) derived from pressure and temperature ramps experiment along with the comparison with previous SANS results are here reported to give additional experimental support to the solvent density-driven aggregation process.

Effects of stimulated hip extension moment and position on upper-limb support forces during FNS-induced standing--a technical note

This study explores the effects of active hip extension moment produced by electrical stimulation on the support forces the arms must exert through an assistive device during quiet erect standing with functional neuromuscular stimulation (FNS) in individuals with spinal cord injuries (SCI). A static sagittal plane biomechanical model of human standing was developed to predict the effects of stimulated hip extension moment and sagittal plane hip angle on the arm support necessary to maintain an upright posture. Two individuals with complete thoracic SCI were then tested while they stood with continuous stimulation to the knee and trunk extensors. The steady-state active extension moment exerted at the hip was varied by activating different combinations of hip extensor muscles with continuous stimulation while steady-state support forces applied to the arms and feet during standing were measured. The steady-state support forces imposed on the arms during quiet standing decrease with increased stimulated hip extension moment and are highly dependent upon hip flexion angle, as predicted by the biomechanical simulations. Experimentally, the combination of gluteus maximus and semimembranosus stimulation produced three times more steady-state hip extension moment than did stimulation of the gluteus maximus and adductor magnus. This resulted in a ten-fold decrease in body weight supported on the arms. More vertical postures (smaller hip flexion angles) improve the effectiveness of the hip extensor muscles in reducing the support forces placed on the arms. A single Newton-meter of stimulated hip extension moment with the hips fixed at 5 degrees of flexion results in almost five times the reduction in arm support forces as with the hips at 20 degrees. To minimize the forces applied by the arms on an assistive device for support while standing with FNS, these preliminary results suggest that (1) efforts should be made to assume the most erect postures possible and (2) muscles and stimulation paradigms that maximize active hip extension moment should be chosen.

Defective neurogenesis in citron kinase knockout mice by altered cytokinesis and massive apoptosis

Citron-kinase (Citron-K) has been proposed by in vitro studies as a crucial effector of Rho in regulation of cytokinesis. To further investigate in vivo its biologic functions, we have inactivated Citron-K gene in mice by homologous recombination. Citron-K-/- mice grow at slower rates, are severely ataxic, and die before adulthood as a consequence of fatal seizures. Their brains display defective neurogenesis, with depletion of specific neuronal populations. These abnormalities arise during development of the central nervous system due to altered cytokinesis and massive apoptosis. Our results indicate that Citron-K is essential for cytokinesis in vivo but only in specific neuronal precursors. Moreover, they suggest a novel molecular mechanism for a subset of human malformative syndromes of the CNS.

Critical micellization density: A small-angle-scattering structural study of the monomer-aggregate transition of block copolymers in supercritical CO2

In this paper we report a small-angle neutron-scattering investigation of micelle formation by the fluorocarbon-hydrocarbon block copolymer, polyvinyl acetate-b-poly (1,1,2, 2-tetrahydroperfluoro-octyl acrylate) in supercritical CO2 (scCO(2)) at 313 K. At high pressure the copolymer is in a monomeric state with a random coil structure, while at low pressure the polymer forms spherical aggregates stable in a wide range of thermodynamic conditions. By profiling pressure, a sharp monomer-micelle transition is obtained due to the tuning of the solvating ability of scCO(2). We confirm the previous finding that this aggregate-monomer transition is driven by the gradual penetration of CO2 molecules toward the core of the aggregate and is critically related to the density of the solvent, thus giving additional support to the concept of a critical micellization density reported earlier on a similar polymer.