Surgery for breast cancer in the elderly--how relevant?

Studies suggest that elderly women receive less aggressive treatment, experience higher disease progression and mortality from breast cancer. We report on an experience of 256 consecutive cases of symptomatic breast cancer in a population of over 75 years of age. 142/256 patients underwent surgical intervention in the form of breast conserving surgery or mastectomy, 114/256 did not. Mean follow up was 6.4 years. Our results show a statistically significant association between surgery and survival (p = 0.05, CI 0.00046-0.19641) and a strong statistically significant association between surgery and disease progression/recurrence (p = 0.001, CI 0.08713-0.03145). Women treated conservatively are significantly less fit hence suffering high cancer unrelated mortality; as a consequence they suffer higher disease related progression and mortality. In our study surgical treatment with adjuvant endocrine and/or radiotherapy was associated with a statistically significant advantage in terms of disease related mortality and local disease control.     

Numerical Simulations of Particle Sedimentation Using the Immersed Boundary Method

We study the settling of solid particles in a viscous incompressible fluid contained within a two-dimensional channel, where the mass density of the particles is greater than that of the fluid. The fluid-structure interaction problem is simulated numerically using the immersed boundary method, where the added mass is incorporated using a Boussinesq approximation. Simulations are performed with a single circular particle, and also with two particles in various initial configurations. The terminal particle settling velocity and drag coefficient correspond closely with other theoretical, experimental and numerical results, and the particle trajectories reproduce the expected behavior qualitatively. In particular, simulations of a pair of interacting particles similar drafting-kissing-tumbling dynamics to that observed in other experimental and numerical studies.     

Clinical/pathologic features and patient outcome in early onset endometrial carcinoma: a population based analysis and an institutional perspective from the Detroit metropolitan area, Michigan

Objective

Analyze tumor characteristics and outcomes in patients with endometrial carcinoma (EC) < 40 years of age and compare them to the characteristics of patients ≥ 40 years of age.

Methods

10,700 patients (305 patients < 40 years of age) diagnosed between 1988 and 2007 with EC from the Metropolitan Detroit Cancer Surveillance System (MDCSS), and 884 patients (42 patients < 40 years of age) diagnosed between 1996 and 2008 with EC from our institutional database were identified. Differences in clinical and demographic variables by age (< 40 vs. ≥ 40) were assessed for statistical significance by chi-square tests. Cox proportional hazards models were used to calculate adjusted hazard ratios (HR) and their 95% confidence intervals (95% CI) to assess the risk of death from all causes.

Results

MDCSS based analysis: Patients < 40 were more likely to present with low grade tumors (p < 0.0001) and endometroid histology (p = 0.0004) but less likely to undergo surgery (p = 0.0007) or radiotherapy (p = 0.0007). A multivariate analysis confirmed the significance of age, grade, and stage in all patients, and that of histologic type, surgery, and race in patients ≥ 40 as independent prognostic factors for overall survival. Institution based analysis: Patients < 40 had a higher proportion of patients with BMI ≥ 30 (p = 0.04), and presented with a higher frequency of well differentiated (p = 0.04) endometrioid tumors (p = 0.004) that are less prone to have deep myometrial invasion (p = 0.008).

Conclusion

This study supports the hypothesis of a disease that is biologically and genetically heterogeneous among women of different ages and ethnicities.     

Simulating Biofilm Deformation and Detachment with the Immersed Boundary Method

We apply the immersed boundary (or IB) method to simulate deformation and detachment of a periodic array of wall-bounded biofilm colonies in response to a linear shear flow. The biofilm material is represented as a network of Hookean springs that are placed along the edges of a triangulation of the biofilm region. The interfacial shear stress, lift and drag forces acting on the biofilm colony are computed by using fluid stress jump method developed by Williams, Fauci and Gaver [Disc. Contin. Dyn. Sys. B 11(2):519–540, 2009], with a modified version of their exclusion filter. Our detachment criterion is based on the novel concept of an averaged equivalent continuum stress tensor defined at each IB point in the biofilm which is then used to determine a corresponding von Mises yield stress; wherever this yield stress exceeds a given critical threshold the connections to that node are severed, thereby signalling the onset of a detachment event. In order to capture the deformation and detachment behaviour of a biofilm colony at different stages of growth, we consider a family of four biofilm shapes with varying aspect ratio. For each aspect ratio, we varied the spacing between colonies to investigate role of spatial clustering in offering protection against detachment. Our numerical simulations focus on the behaviour of weak biofilms (with relatively low yield stress threshold) and investigate features of the fluid-structure interaction such as locations of maximum shear and increased drag. The most important conclusions of this work are: (a) reducing the spacing between colonies reduces drag by from 50 to 100% and alters the interfacial shear stress profile, suggesting that even weak biofilms may be able to grow into tall structures because of the protection they gain from spatial proximity with other colonies; (b) the commonly employed detachment strategy in biofilm models based only on interfacial shear stress can lead to incorrect or inaccurate results when applied to the study of shear induced detachment of weak biofilms. Our detachment strategy based on equivalent continuum stresses provides a unified and consistent IB framework that handles both sloughing and erosion modes of biofilm detachment, and is consistent with strategies employed in many other continuum based biofilm models.     

Vacuolated cell pattern of pancreatobiliary adenocarcinoma: a clinicopathological analysis of 24 cases of a poorly recognized distinctive morphologic variant important in the differential diagnosis

Pancreatic ductal adenocarcinoma (PDCA) is characterized by well-defined tubular units in the vast majority of the cases; however, variations in this theme do occur. It is important to recognize the morphologic spectrum of PDCA to avoid misdiagnosis especially in small specimens and also in metastatic foci. Here, we document a morphologic variant of PDCA that is characterized by a distinctive pattern of infiltrating cribriform nests in a distinctive “microcystic” or “secretory” pattern. Twenty-four cases of PDCA have been identified in a review of 505 cases diagnosed with PDCA. Histologically, this pattern was characterized by infiltrating nests of tumor cells with large vacuoles and “signet-ring” like appearance imparting a cribriform growth pattern. The vacuoles were one to five cells in size, often merging to form multilocular spaces separated by a thin rim of cell membrane. Many of these spaces contained CA19.9 positive granular secretory material. The nuclei were often pushed to the periphery and compressed in a pattern resembling adipocytes, although the nuclei were often densely hyperchromatic and displayed significant atypia. Especially in biopsies from the peripancreatic fat and peritoneum, these neoplastic cells had been misdiagnosed as degenerating adipocytes, and in the lymph nodes, they had been misinterpreted as lipogranulomas. Clinical findings of the patients were similar to that of conventional PDCA, except higher incidence of history of smoking (83% vs. 60%; p = 0.034). In conclusion, vacuolated cell adenocarcinoma is a distinct morphologic variant of PDCA, and the presence of this peculiar pattern in a metastatic site, although not specific, should raise the suspicion of a PDCA.     

Fine needle aspiration of head and neck masses in the operating room: accuracy and potential benefits

Fine needle aspiration (FNA) in the operating room is a convenient optional diagnostic approach. Our objective of this study was to evaluate the accuracy and study the potential benefits of fine needle aspiration in the operating room. Retrospective review of all intraoperative FNA that were requested and performed by pathologists over 20-month period was carried out. Immediate smears were interpreted by the cytopathology team after staining with Diff Quik stain. All cases were reviewed and correlation with subsequent tissue diagnosis was done. Accuracy was calculated and potential benefits were discussed. The number of aspirates was 32. Adequate material for immediate and final interpretation was achieved in 31 cases (sensitivity 97%). In 20 cases (63%), malignancy was diagnosed while a benign diagnosis was rendered in 12 (37%). All cases had a follow up tissue diagnosis. No false-positive cases were identified (specificity 100%). The information gained from this approach was considered helpful to the surgeons. We concluded that FNA of head and neck masses in the operating room is an accurate and sensitive diagnostic approach. The service provides helpful information to surgeons and is an additional optional diagnostic approach.     

High-field magnetic resonance imaging of brain iron in Alzheimer disease

OBJECTIVES: Increased iron deposition in the brain may occur in several neurodegenerative diseases, including Alzheimer disease (AD). Iron deposits shorten T2 relaxation times on T2-weighted magnetic resonance (MR) images. Iron-dependent contrast increases with magnetic field strength. We hypothesized that T2 mapping using 3 T MR imaging (MRI) can disclose differences between normal controls and AD subjects. METHODS: High-resolution brain imaging protocols were developed and applied to 24 AD patients and 20 age-matched controls using 3 T MRI. Eight anatomical regions of interest were manually segmented, and T2 histograms were computed. A visual analysis technique, the heat map, was modified and applied to the large image data sets generated by these protocols. RESULTS: A large number (163) of features from these histograms were examined, and 38 of these were significantly different (P < 0.05) between the groups. In the hippocampus, evidence was found for AD-related increases in iron deposition (shortened T2) and in the concentration of free tissue water (lengthened T2). Imaging of a section of postmortem brain before and after chemically extracting the iron established the presence of MRI-detectable iron in the hippocampus, cortex, and white matter in addition to brain regions traditionally viewed as containing high iron concentrations.