Patterns of Recurrence after Neoadjuvant Therapy in Early Breast Cancer, according to the Residual Cancer Burden Index and Reductions in Neoadjuvant Treatment Intensity.

BACKGROUND: The prognostic performance of the residual cancer burden (RCB) score is a promising tool for breast cancer patients undergoing neoadjuvant therapy. We independently evaluated the prognostic value of RCB scores in an extended validation cohort. Additionally, we analyzed the association between chemotherapy dose reduction and RCB scores. METHODS: In this extended validation study, 367 breast cancer patients with available RCB scores were followed up for recurrence-free survival (RFS), distant disease-free survival (DDFS), and overall survival (OS). We also computed standardized cumulative doses of anthracyclines and taxanes (A/Ts) to investigate a potential interaction between neoadjuvant chemotherapy dose reduction and RCB scores. RESULTS: Higher RCB scores were consistently associated with adverse clinical outcomes across different molecular subtypes (HR for RFS = 1.60, 95% CI 1.33-1.93, p < 0.0001; HR for DDFS = 1.70, 95% CI 1.39-2.05, p < 0.0001; HR for OS = 1.67, 95% CI 1.34-2.08, p < 0.0001). The adverse impact prevailed throughout 5 years of follow-up, with a peak for relapse risk between 1-2 years after surgery. Clinical outcomes of patients with RCB class 1 did not differ substantially at 5 years compared to RCB class 0. A total of 180 patients (49.1%) underwent dose reduction of neoadjuvant A/T chemotherapy. We observed a statistically significant interaction between dose reduction and higher RCB scores (interaction p-value = 0.042). CONCLUSION: Our results confirm RCB score as a prognostic marker for RFS, DDFS, and OS independent of the molecular subtype. Importantly, we show that lower doses of cumulative neoadjuvant A/T were associated with higher RCB scores in patients who required a dose reduction.

Tailored disorder: a self-organized photonic contact for light trapping in silicon-based tandem solar cells.

We present a process development leading to efficient rear side light trapping structures with the purpose of enhancing the infrared response of a silicon-based tandem solar cell. To this end, we make use of phase separation effects of two immiscible polymers, polystyrene and poly(methyl methacrylate), resulting in a non-periodic polystyrene structure on silicon with a well-defined size distribution. Onto this pattern, we evaporate silver as a scattering rear side mirror and contact layer. Average feature sizes and periods can be tuned by varying material properties (e.g. molar weights or ratios of the polymers) as well as processing conditions during the spin coating. This way a favorable pseudo period of approx. 1 µm for these disordered structure features was realized and successfully implemented into a silicon solar cell. The structure shows a ring-shaped scattering distribution which is beneficial for light trapping in solar cells. External quantum efficiency measurements show that a gain in short circuit current density of 1.1 mA/cm2 compared to a planar reference can be achieved, which is in the same range as we achieved using nanoimprint lithography in a record triple-junction III/V on a silicon device.

Validation of Residual Cancer Burden as Prognostic Factor for Breast Cancer Patients After Neoadjuvant Therapy.

BACKGROUND: Assessing the residual cancer burden (RCB) predictive performance, the potential subgroup effects, and time-dependent impact on breast cancer patients who underwent neoadjuvant therapy in a developer's independent cohort is essential for its usage in clinical routine. METHODS: Between 2011 and 2016, the RCB scores of 184 female breast cancer patients were prospectively collected, and subsequent clinicopathological and follow-up data were obtained retrospectively. Recurrence-free survival (RFS), overall survival (OS), as well as subgroup analysis, and time-dependent variables were calculated with multivariate, complex, or linear statistical models. RESULTS: A total of 184 patients (HER2 33%, TNBC 27%), with a mean follow-up time of 4 years, treated with neoadjuvant systemic therapy (92% anthracycline-taxane based) were analyzed revealing 43 events (38 recurrences, 28 deaths). High RCB scores were associated with recurrence (median index: 2.34 vs. 1.39 points, rank-sum p < 0.0001), decreased RFS (hazard ratio [HR] = 1.80, 95% confidence interval [CI] 1.44-2.24, p < 0.0001) and reduced OS (HR 1.96, 95% CI 1.49-2.59, p < 0.0001). The RCB score showed proportionality of hazards (interaction HR with linear follow-up time = 1.00, p = 0.896) and good discriminating power (Harrell's c index 0.7). CONCLUSIONS: Our results confirm the RCB score as externally valid prognostic marker and being independent of molecular subtype for RFS and OS in a clinical setting.

Broadband antireflection Mie scatterers revisited-a solar cell and module analysis.

Reflectance, reduction, and light trapping enhancement are essential to maximize the absorption of silicon solar cells. The industrial state of the art method to improve the solar cell optics is wet chemical texturization of the front surface in combination with the deposition of antireflection coatings. This work analyzes an alternative route, namely a TiO2 pillar structure on the front side of a planar silicon solar cell encapsulated in ethylene vinyl acetate (EVA) and glass. It focuses on parameter variations of the structured TiO2 layer while taking the module encapsulation into account. It is shown that internal reflections at the front interface of the module play a crucial role for the structure design. This leads to optimized structures working in a different optical regime. While state of the art structures optimized for a half infinite encapsulation act as effective media, structures optimized for the full module show an improved performance by making use of diffractive effects. It could be shown that weighted reflectance of 4.7% can be reached for a solar module with TiO2 pillar structure on top of the silicon surface compared to 5.5% for a two-layer ARC with a TiO2 bottom layer and 2.3% for an isotexture, which is the state of the art structure for multicrystalline silicon cells.

Optical simulation of photovoltaic modules with multiple textured interfaces using the matrix-based formalism OPTOS.

The OPTOS formalism is a matrix-based approach to determine the optical properties of textured optical sheets. It is extended within this work to enable the modelling of systems with an arbitrary number of textured, plane-parallel interfaces. A matrix-based system description is derived that accounts for the optical reflection and transmission interaction between all textured interfaces. Using OPTOS, we calculate reflectance and absorptance of complete photovoltaic module stacks, which consist of encapsulated silicon solar cells featuring textures that operate in different optical regimes. As exemplary systems, solar cells with and without module encapsulation are shown to exhibit a considerable absorptance gain if the random pyramid front side texture is combined with a diffractive rear side grating. A variation of the sunlight's angle of incidence reveals that the grating gain is almost not affected for incoming polar angles up to 60°. Considering as well the good agreement with alternative simulation techniques, OPTOS is demonstrated to be a versatile and efficient method for the optical analysis of photovoltaic modules.

3D optical simulation formalism OPTOS for textured silicon solar cells.

In this paper we introduce the three-dimensional formulation of the OPTOS formalism, a matrix-based method that allows for the efficient simulation of non-coherent light propagation and absorption in thick textured sheets. As application examples, we calculate the absorptance of solar cells featuring textures on front and rear side with different feature sizes operating in different optical regimes. A discretization of polar and azimuth angle enables a three-dimensional description of systems with arbitrary surface textures. We present redistribution matrices for 3D surface textures, including pyramidal textures, binary crossed gratings and a Lambertian scatterer. The results of the OPTOS simulations for silicon sheets with different combinations of these surfaces are in accordance with both optical measurements and results based on established simulation methods like ray tracing. Using OPTOS, we show that the integration of a diffractive grating at the rear side of a silicon solar cell featuring a pyramidal front side results in absorption close to the Yablonovitch Limit enhancing the photocurrent density by 0.6 mA/cm2 for a 200 µm thick cell.

Matrix formalism for light propagation and absorption in thick textured optical sheets.

In this paper, we introduce a simulation formalism for determining the Optical Properties of Textured Optical Sheets (OPTOS). Our matrix-based method allows for the computationally-efficient calculation of non-coherent light propagation and absorption in thick textured sheets, especially solar cells, featuring different textures on front and rear side that may operate in different optical regimes. Within the simulated system, the angular power distribution is represented by a vector. This light distribution is modified by interaction with the surfaces of the textured sheets, which are described by redistribution matrices. These matrices can be calculated for each individual surface texture with the most appropriate technique. Depending on the feature size of the texture, for example, either ray- or wave-optical methods can be used. The comparison of the simulated absorption in a sheet of silicon for a variety of surface textures, both with the results from other simulation techniques and experimentally measured data, shows very good agreement. To demonstrate the versatility of this newly-developed approach, the absorption in silicon sheets with a large-scale structure (V-grooves) at the front side and a small-scale structure (diffraction grating) at the rear side is calculated. Moreover, with minimal computational effort, a thickness parameter variation is performed.

Nanoimprinted diffraction gratings for crystalline silicon solar cells: implementation, characterization and simulation.

Light trapping is becoming of increasing importance in crystalline silicon solar cells as thinner wafers are used to reduce costs. In this work, we report on light trapping by rear-side diffraction gratings produced by nano-imprint lithography using interference lithography as the mastering technology. Gratings fabricated on crystalline silicon wafers are shown to provide significant absorption enhancements. Through a combination of optical measurement and simulation, it is shown that the crossed grating provides better absorption enhancement than the linear grating, and that the parasitic reflector absorption is reduced by planarizing the rear reflector, leading to an increase in the useful absorption in the silicon. Finally, electro-optical simulations are performed of solar cells employing the fabricated grating structures to estimate efficiency enhancement potential.

[Consensus statement haemorrhoidal disease]. / Konsensusbericht Hämorrhoidalleiden.

Haemorrhoidal disease belongs to the most common benign disorders in the lower gastrointestinal tract. Treatment options comprise conservative as well as surgical therapy still being applied arbitrarily in accordance with the surgeon's expertise. The aim of this consensus statement was therefore to assess a stage-dependent approach for treatment of haemorrhoidal disease to derive evidence-based recommendations for clinical routine. The most common methods are discussed with respect of haemorrhoidal disease in extraordinary conditions like pregnancy or inflammatory bowel disease and recurrent haemorrhoids. Tailored haemorrhoidectomy is preferable for individualized treatment with regard to the shortcomings of the traditional Goligher classification in solitary or circular haemorrhoidal prolapses.

Juvenile polyposis of the stomach causing recurrent upper gastrointestinal bleeding.

We present the case of a 42-year-old man who suffered from recurrent severe upper gastrointestinal bleeding starting from February 2003. Endoscopy showed multiple glassy polyps in the stomach, which corresponded to a diffuse mucosal thickening detected by endosonography. The duodenum was normal. In February 2006, life-threatening acute gastrointestinal bleeding prompted total gastrectomy. The resection specimen showed the gastric mucosa carpeted by numerous glassy pedunculated polyps, measuring 2 cm in largest diameter. Histologically, the polyps were characterized by an abundant loose stroma and by elongated, twisting foveolae, covered by hyperplastic epithelium. Colonoscopy including the terminal ileum revealed a single tubulovillous adenoma, but no hamartomatous polyps, rendering a final diagnosis of juvenile polyposis of the stomach. This case represents the first description of juvenile polyposis causing life-threatening gastric haemorrhage. Thus, although rare, the disease has to be considered in the differential diagnosis of patients with acute upper gastrointestinal tract bleeding.

Colliding / concomitant tumors of the intestine: report of 3 cases.

Collision/concomitant tumors of the intestine involving lymphomas are very rare. For these cases molecular genetic analyses are valuable diagnostic adjuncts. We report one collision tumor of the rectum (adenocarcinoma and peripheral T-cell lymphoma, unspecified), and two cases of concomitant tumors (carcinoma in the cecum and lymphoma in the ileum; carcinoma in the sigmoid and lymphoma in the ileum). The collision tumor (poorly differentiated adenocarcinoma and a peripheral T-cell lymphoma, unspecified) showed a variable proportion of the anaplastic tumor cells expressing lymphatic markers as well as cytokeratin. Only polymerase chain reaction (PCR) analysis revealing T-cell monoclonality of the anaplastic part of the colliding tumor allowed the correct diagnosis. In the second case, a moderately differentiated adenocarcinoma in the cecum with a concomitant B-cell Non-Hodgkin lymphoma in the ileum, PCR analysis was non contributory. In the third case (adenocarcinoma in the sigmoid colon and a follicular center lymphoma in the ileum) PCR analysis revealed gene rearrangement of the immunoglobulin heavy chain gene. We would like to emphasize that collision and concomitant tumors of the gut are rare and that molecular genetic analysis may be mandatory for correct diagnosis. It is our impression, that these tumors may be diagnosed more often in the intestinal tract if molecular genetic analysis and immunohistochemistry are used routinely, at least for all anaplastic tumors.