Comparison of Human Surrogate Responses in Underbody Blast Loading Conditions.

Impact biomechanics research in occupant safety predominantly focuses on the effects of loads applied to human subjects during automotive collisions. Characterization of the biomechanical response under such loading conditions is an active and important area of investigation. However, critical knowledge gaps remain in our understanding of human biomechanical response and injury tolerance under vertically accelerated loading conditions experienced due to underbody blast (UBB) events. This knowledge gap is reflected in anthropomorphic test devices (ATDs) used to assess occupant safety. Experiments are needed to characterize biomechanical response under UBB relevant loading conditions. Matched pair experiments in which an existing ATD is evaluated in the same conditions as a post mortem human subject (PMHS) may be utilized to evaluate biofidelity and injury prediction capabilities, as well as ATD durability, under vertical loading. To characterize whole body response in the vertical direction, six whole body PMHS tests were completed under two vertical loading conditions. A series of 50th percentile hybrid III ATD tests were completed under the same conditions. Ability of the hybrid III to represent the PMHS response was evaluated using a standard evaluation metric. Tibial accelerations were comparable in both response shape and magnitude, while other sensor locations had large variations in response. Posttest inspection of the hybrid III revealed damage to the pelvis foam and skin, which resulted in large variations in pelvis response. This work provides an initial characterization of the response of the seated hybrid III ATD and PMHS under high rate vertical accelerative loading.

Optical absorption of composition-tunable InGaAs nanowire arrays.

InGaAs nanowire (NW) arrays have emerged as important active materials in future photovoltaic and photodetector applications, due to their excellent electronic properties and tunable band gap. Here, we report a systematic investigation of the optical absorption characteristics of composition-tunable vertical InGaAs NW arrays. Using finite-difference time-domain simulations we first study the effect of variable composition (Ga-molar fraction) and NW array geometry (NW diameter, period, fill factor) on the optical generation rate. NWs with typical diameters in the range of ∼100-250 nm lead to generation rates higher than the equivalent bulk case for moderate fill factors (NW period of ∼0.3-0.8 µm), while slightly smaller fill factors and increased diameters are required to maintain high generation rates at increased Ga-molar fraction. The optical absorption was further measured using spectrally resolved ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy on NW arrays transferred to transparent substrates. Interestingly, large variations in Ga-molar fraction (0 < x(Ga) < 0.5) have a negligible influence, while minute changes in NW diameter of less than ±20 nm affect the absorption spectra very strongly, leading to pronounced shifts in the peak absorption energies by more than ∼700 meV. These results clearly highlight the much larger sensitivity of the optical absorption behavior to geometric parameters rather than to variations in the electronic band gap of the underlying NW array.

Porphyromonas gingivalis Impairs Oral Epithelial Barrier through Targeting GRHL2.

Oral mucosa provides the first line of defense against a diverse array of environmental and microbial irritants by forming the barrier of epithelial cells interconnected by multiprotein tight junctions (TJ), adherens junctions, desmosomes, and gap junction complexes. Grainyhead-like 2 (GRHL2), an epithelial-specific transcription factor, may play a role in the formation of the mucosal epithelial barrier, as it regulates the expression of the junction proteins. The current study investigated the role of GRHL2 in the Porphyromonas gingivalis (Pg)-induced impairment of epithelial barrier functions. Exposure of human oral keratinocytes (HOK-16B and OKF6 cells) to Pg or Pg-derived lipopolysaccharides (Pg LPSs) led to rapid loss of endogenous GRHL2 and the junction proteins (e.g., zonula occludens, E-cadherin, claudins, and occludin). GRHL2 directly regulated the expression levels of the junction proteins and the epithelial permeability for small molecules (e.g., dextrans and Pg bacteria). To explore the functional role of GRHL2 in oral mucosal barrier, we used a Grhl2 conditional knockout (KO) mouse model, which allows for epithelial tissue-specific Grhl2 KO in an inducible manner. Grhl2 KO impaired the expression of the junction proteins at the junctional epithelium and increased the alveolar bone loss in the ligature-induced periodontitis model. Fluorescence in situ hybridization revealed increased epithelial penetration of oral bacteria in Grhl2 KO mice compared with the wild-type mice. Also, blood loadings of oral bacteria (e.g., Bacteroides, Bacillus, Firmicutes, ß-proteobacteria, and Spirochetes) were significantly elevated in Grhl2 KO mice compared to the wild-type littermates. These data indicate that Pg bacteria may enhance paracellular penetration through oral mucosa in part by targeting the expression of GRHL2 in the oral epithelial cells, which then impairs the epithelial barrier by inhibition of junction protein expression, resulting in increased alveolar tissue destruction and systemic bacteremia.

Quantum Optomechanics in a Liquid.

We measure the quantum fluctuations of a single acoustic mode in a volume of superfluid He that is coupled to an optical cavity. Specifically, we monitor the Stokes and anti-Stokes light scattered by a standing acoustic wave that is confined by the cavity mirrors. The intensity of these signals (and their cross-correlation) exhibits the characteristic features of the acoustic wave's zero-point motion and the quantum backaction of the intracavity light. While these features are also observed in the vibrations of solid objects and ultracold atomic gases, their observation in superfluid He opens the possibility of exploiting the remarkable properties of this material to access new regimes of quantum optomechanics.

Increased exposure of plankton to arsenic in contaminated weakly-stratified lakes.

Arsenic, a priority Superfund contaminant and carcinogen, is a legacy pollutant impacting aquatic ecosystems in urban lakes downwind of the former ASARCO copper smelter in Ruston, WA, now a Superfund site. We examined the mobility of arsenic from contaminated sediments and arsenic bioaccumulation in phytoplankton and zooplankton in lakes with varying mixing regimes. In lakes with strong seasonal thermal stratification, high aqueous arsenic concentrations were limited to anoxic bottom waters that formed during summer stratification, and arsenic concentrations were low in oxic surface waters. However, in weakly-stratified lakes, the entire water column, including the fully oxic surface waters, had elevated concentrations of arsenic (up to 30µgL-1) during the summer. We found enhanced trophic transfer of arsenic through the base of the aquatic food web in weakly-stratified lakes; plankton in these lakes accumulated up to an order of magnitude more arsenic on multiple sampling days than plankton in stratified lakes with similar levels of contamination. We posit that greater bioaccumulation in weakly-stratified lakes was due to elevated arsenic in oxic waters. Aquatic life primarily inhabits oxic waters and in the oxic water column of weakly-stratified lakes arsenic was speciated as arsenate, which is readily taken up by phytoplankton because of its structural similarities to phosphate. Our study indicates that mobilization of arsenic from lake sediments into overlying oxic water columns in weakly-stratified lakes leads to increased arsenic exposure and uptake at the base of the aquatic food web.

Human Papillomavirus 16 E6 Induces FoxM1B in Oral Keratinocytes through GRHL2.

High-risk human papillomavirus (HPV) is a major risk factor for oral and pharyngeal cancers (OPCs), yet the detailed mechanisms by which HPV promotes OPCs are not understood. Forkhead box M1B (FoxM1B) is an oncogene essential for cell cycle progression and tumorigenesis, and it is aberrantly overexpressed in many tumors. We previously showed that FoxM1B was the putative target of an epithelial-specific transcription factor, Grainyhead-like 2 (GRHL2). In the current study, we demonstrate that HPV type 16 (HPV-16) E6 induces FoxM1B in human oral keratinocytes (HOKs) and tonsillar epithelial cells (TECs) in part through GRHL2. FoxM1B was barely detectable in cultured normal human oral keratinocytes (NHOKs) and progressively increased in immortalized HOKs harboring HPV-16 genome (HOK-16B) and tumorigenic HOK-16B/BaP-T cells. Retroviral expression of HPV-16 E6 and/or E7 in NHOKs, TECs, and hypopharyngeal carcinoma cells (FaDu) revealed induction of FoxM1B and GRHL2 by the E6 protein but not E7. Both GRHL2 and FoxM1B were strongly induced in the epidermis of HPV-16 E6 transgenic mice and HPV+ oral squamous cell carcinomas. Ectopic expression of FoxM1B led to acquisition of transformed phenotype in HOK-16B cells. Loss of FoxM1B by lentiviral short hairpin RNA vector or chemical inhibitor led to elimination of tumorigenic characteristics of HOK-16B/BaP-T cells. Luciferase reporter assay revealed that GRHL2 directly bound and regulated the FoxM1B gene promoter activity. Using epithelial-specific Grhl2 conditional knockout mice, we exposed wild-type (WT) and Grhl2 KO mice to 4-nitroquinolin 1-oxide (4-NQO), which led to induction of FoxM1B in the tongue tissues and rampant oral tumor development in the WT mice. However, 4-NQO exposure failed to induce tongue tumors or induction of FoxM1B expression in Grhl2 KO mice. Collectively, these results indicate that HPV-16 induces FoxM1B in part through GRHL2 transcriptional activity and that elevated FoxM1B level is required for oropharyngeal cancer development.

A novel pretherapeutic gene expression-based risk score for treatment guidance in gastric cancer.

Background: Perioperative chemotherapy is an established treatment of advanced gastric cancer patients. Treatment selection is based on clinical staging (cT). We aimed to establish and validate a prognostic score including clinical and molecular factors, to optimize treatment decisions for these patients. Patients and methods: We analyzed 626 carcinomas of the stomach and of the gastro-esophageal junction from two academic centers including primarily resected and pre-/perioperatively treated patients. Patients were divided into a training (N = 269) and validation (N = 357) set. Expression of 11 target genes was measured by quantitative PCR in resected tumors. A risk score to predict overall survival (OS) was generated and validated. Intra-tumoral heterogeneity was assessed by analyzing 50 tumor areas from 10 patients. Results: A risk score including the expression of CCL5, CTNNB1, EXOSC3 and LZTR1 and the clinical parameters cT, tumor localization and histopathologic type suggested two groups with a significant difference in OS [hazard ratio (HR) 0.30; 95% confidence interval (CI) 0.17-0.52]. The risk score was successfully validated in an independent cohort (HR 0.32; 95% CI 0.21-0.51; P < 0.001) as well as in subgroups of primarily resected (HR 0.30; 95% CI 0.17-0.54; P < 0.001) and pre-/perioperatively treated patients (HR 0.37; 95% CI 0.17-0.81; P = 0.009). A significant difference in OS of high- and low-risk patients was also found in primarily resected patients with intestinal (HR 0.45; 95% CI 0.23-0.90; P = 0.020) and nonintestinal-type carcinomas (HR 0.1; 95% CI 0.02-0.42; P < 0.001). Intra-tumor heterogeneity analysis indicated a classification reliability of 95% for a supposed analysis of three biopsies. Conclusion: The identified risk score could substantially contribute to an improved management of gastric cancer patients in the context of perioperative chemotherapy.

[Pacemaker, defibrillator and co : Perioperative handling of cardiac implantable electronic devices]. / Schrittmacher, Defi & Co : Der perioperative Umgang mit "cardiac implantable electronic devices".

The number of patients treated with cardiac implantable electronic devices (CIED) is continously increasing. Knowledge of the medical indications and technical mode of functioning of these devices is a basic prerequisite for the safe perioperative care of this patient cohort. The CIEDs are subjected to a multitude of disturbing influences in the perioperative setting. This can result in potentially dangerous complications, such as exit block and oversensing. The safe performance of interventions is possible as long as some basic rules are followed. An interdisciplinary approach involving all participating disciplines is necessary in order to adequately deal with the high demands placed on the logistics.

[Gastric stump carcinoma: frequency, treatment, complications and prognosis]. / Magenstumpfkarzinom: Häufigkeit, Therapie, Komplikationen und Prognose.

BACKGROUND: Gastric stump carcinoma develops in the gastric remnant after partial gastrectomy. While the frequency of gastric cancer is declining, the incidence of gastric stump carcinoma has remained stable due to the long latency period. As the surgical treatment of gastric ulcers by partial gastrectomy has become much less important, more and more gastric stump carcinomas develop after oncological resection. AIM: This study compared the surgical therapy of gastric stump carcinoma with the therapy of primary gastric cancer. MATERIAL AND METHODS: From 2001 to 2014 a total of 24 patients were surgically treated for gastric stump carcinoma in the University Hospital of Heidelberg. In the same time 428 patients underwent resection due to primary gastric cancer. Both groups were analyzed and compared with a focus on preoperative therapy, intraoperative differences, complications and overall survival. RESULTS: Patients with gastric stump carcinoma were older at disease onset (68 years vs. 62 years, p = 0.003). Compared with primary gastric cancer, patients with gastric stump carcinoma were more often suspected of having lymph node (cN+) involvement (51.4 % vs. 41.7 %, p < 0.001) but neoadjuvant therapy was applied less often (48.7 % vs. 14.3 %, p < 0.01). For resection of gastric stump carcinoma, extended resections were more often necessary (54.5 % vs. 28.2 %, p < 0.001). There were no significant differences in mean overall survival between the two patient groups (64.4 months vs. 45.8 months, p = 0.34) CONCLUSION: Despite the differences described, the treatment of gastric stump carcinoma does not essentially differ from that of primary gastric cancer. Carcinomas of the gastric stump are more often locally advanced and in our opinion a neoadjuvant therapy should be applied analogue to gastric cancer even if evidence-based data on this point are limited.

Biomarkers in acute kidney injury - pathophysiological basis and clinical performance.

Various biomarkers of acute kidney injury (AKI) have been discovered and characterized in the recent past. These molecules can be detected in urine or blood and signify structural damage to the kidney. Clinically, they are proposed as adjunct diagnostics to serum creatinine and urinary output to improve the early detection, differential diagnosis and prognostic assessment of AKI. The most obvious requirements for a biomarker include its reflection of the underlying pathophysiology of the disease. Hence, a biomarker of AKI should derive from the injured kidney and reflect a molecular process intimately connected with tissue injury. Here, we provide an overview of the basic pathophysiology, the cellular sources and the clinical performance of the most important currently proposed biomarkers of AKI: neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver-type fatty acid-binding protein (L-FABP), interleukin-18 (IL-18), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor of metalloproteinase 2 (TIMP-2) and calprotectin (S100A8/9). We also acknowledge each biomarker's advantages and disadvantages as well as important knowledge gaps and perspectives for future studies.

Surgery in oesophago-gastric cancer with metastatic disease: Treatment, prognosis and preoperative patient selection.

BACKGROUND: The role of surgical resection in metastatic oesophago-gastric adenocarcinomas (EGA) is not defined and regularly discussed in interdisciplinary tumour boards. Primary objective of this retrospective study was the outcome of patients after surgery. We additionally evaluated our preoperative prognostic score (PPS) based on tumour grading, clinical response to chemotherapy and presumed R-status. METHODS: 123 of 811 EGA patients were evaluated as cM1, either confirmed intraoperatively or by imaging. Response evaluation after chemotherapy was performed by endoscopy, CT-scan and histopathologically. The prospectively documented patient and outcome data were analysed retrospectively. RESULTS: 70 patients with adenocarcinoma of the oesophago-gastric junction and 53 patients with gastric cancer were included. The majority had one M1 site (n = 102). 72 received preoperative chemotherapy (CTx) and 51 underwent primary resection. 11 were explored without resection. 49/112 (40%) had multivisceral resections and 63/112 (56%) were completely resected (R0). 26/72 (36%) were clinical responders and 30 patients had a favourable PPS. Median survival was 20.0 months. Survival was significantly prolonged by resection, especially complete resection, and by preoperative CTx (all p = 0.001). Multivisceral resection, type or number of metastases, or primary tumour localization had no impact on survival. In patients undergoing preoperative CTx, clinical response and the PPS influenced survival significantly. In R0 resected patients, preoperative CTx, clinical response and the PPS remained prognostic. CONCLUSION: Primary resection without preoperative CTx is not appropriate for metastatic EGA. Subgroups of patients with a favourable PPS with response to CTx may be good candidates for surgical resection in metastatic oesophago-gastric cancer.

[Are There Gender-Specific Differences in Complications Following Abdominal Surgery?]. / Gibt es geschlechterspezifische Unterschiede bei Komplikationen in der offenen Viszeralchirurgie?

Studies in mice indicate gender-specific differences in surgical complications with a distinct advantage for females. In patient care, however, gender has been an underrated aspect of complication management in abdominal surgery as far. Proven differences between the sexes regarding anatomy, hormonal regulation, constitutional polymorphisms, immune response and psychology suggest different types and incidence of complications and seem to justify studies on the topic. This review aims to compare a selection of current original articles reporting on complications following abdominal surgery separately for the genders. However, data in the literature are sparse and in part very heterogeneous. With data on colorectal carcinoma being most comprehensive, for stomach, oesophagus and finally pancreas fewer data can be found. Summing up all organ systems, the following cautious conclusions can be drawn. Men tend to suffer from postoperative complications more frequently. Men have more cases of anastomotic leakage, whereas women suffer from anastomotic stenosis more often. Currently, however, existing data do not justify any adaptation of patient management. Thus, taking gender aspects into account in designing new trials is paramount in order to obtain robust gender-specific data on incidence and types of complications.

[Gender Aspects in Gastrointestinal Tumours and Their Prognosis in Regard to Multimodal Treatment Concepts]. / Genderaspekte bei Tumoren des Gastrointestinaltrakts und ihre Prognose, insbesondere im Rahmen multimodaler Therapiekonzepte.

Systematic analyses of gender effects in gastrointestinal malignancies are currently lacking, partly because sex and gender have not been used as stratification criteria in major studies on the topic. It is, however, indisputable that gastrointestinal tumours differ in risk factors, incidence and prognosis between the genders. This review summarises the most important findings on differences related to biological sex and sociocultural gender and discusses anatomic specifics with immediate significance for surgical interventions. Epidemiological differences in upper gastrointestinal malignancies are most prominent in regard to histological subtypes, directly affecting diagnostics, therapy, and prognosis. Women have a better prognosis in many of these tumour subtypes. For colorectal carcinoma, sex hormones, specifically oestrogens, appear to play a distinct role in tumourigenesis. Histopathological analysis of the expression of oestrogen receptor beta (ERß) in the tumour tissue has attracted interest since it was shown that women with low ERß expression have a better prognosis than men with comparable ERß status. Data on the higher incidence of right-sided colon carcinoma and non-polypoid neoplasms in women could lead to improved screening programmes. Men and women cite differing reasons for avoidance of screening colonoscopies, thus gender specific approaches could improve colon cancer prevention programmes. Data on differing bioavailability of 5-fluorouracil between the genders are useful to minimise adverse effects of chemotherapy and should be accounted for in dosage. Further systematic analysis of gender effects on gastrointestinal tumours is warranted and would be a substantial step towards personalised oncological surgery.

Material Parameter Determination of an L4-L5 Motion Segment Finite Element Model Under High Loading Rates.

Underbody blast (UBB) events impart vertical loads through a victim’s lumbar spine, resulting in fracture, paralysis, and disc rupture. Validated biofidelic lumbar models allow characterization of injury mechanisms and development of personal protective equipment. Previous studies have focused on lumbar mechanics under quasi-static loading. However, it is unclear how the role and response of individual spinal components of the lumbar spine change under dynamic loading. The present study leverages high-rate impacts of progressively dissected two-vertebra lumbar motion segments and Split-Hopkinson pressure bar tissue characterization to identify and validate material properties of a high-fidelity lumbar spine finite element model for UBB. The annulus fibrosus was modeled as a fiber-reinforced Mooney-Rivlin material, while ligaments were represented by nonlinear spring elements. Optimization and evaluation of material parameters was achieved by minimizing the root-mean-square (RMS) of compressive displacement and sagittal rotation for selected experimental conditions. Applying dynamic based material models and parameters resulted in a 0.42% difference between predicted and experiment axial compression during impact loading. This dynamically optimized lumbar model is suited for cross validation against whole-lumbar loading scenarios, and prediction of injury during UBB and other dynamic events.

[Salvage surgery in esophageal cancer : Feasibility in patients after definitive radiochemotherapy (> 50 Gy)]. / Salvage-Chirurgie bei Ösophaguskarzinomen : Sinnvoll bei Patienten nach definitiver Radio(chemo)therapie (> 50 Gy)?

BACKGROUND: Salvage surgery as an additional therapy option is currently discussed for an increasing number of patients with esophageal cancer after definitive radio(chemo)therapy after tumor progression, recurrence or on explicit request of the patient. OBJECTIVES: The objective of this study was an analysis of the surgical option of salvage esophagectomy after definitive radiation in patients with esophageal cancer. Additionally the current literature on this topic was evaluated. MATERIAL AND METHODS: A total of 92 patients with esophageal cancer from a prospective database were included in this study who underwent esophagectomy either after neoadjuvant radio(chemo)therapy (< 50 Gy) or definitive radio(chemo)therapy (> 50 Gy) between 2002 and 2012. The analysis was performed retrospectively. RESULTS: The median survival of the two groups of patients was not significantly different after initial diagnosis with 24.2 months (95 % CI 0.0-51.93) for patients undergoing definitive radio(chemo)therapy and 30.7 months (95 % CI 9.3-52.2) for patients after neoadjuvant therapy (p = 0.96). Both patient groups showed no differences in pretherapeutic characteristics and response to radio(chemo)therapy. Postoperative complications and perioperative mortality were not different. DISCUSSION: Salvage esophagectomy is now an additional treatment option after definitive radio(chemo)therapy in patients with esophageal cancer. In preselected patients with tumor recurrence, progression or with a strong wish for surgical therapy, salvage surgery should be discussed in interdisciplinary tumor boards after exclusion of distant metastases.

[Importance of PET in surgery of esophageal cancer]. / Bedeutung der PET für die Chirurgie des Ösophaguskarzinoms.

Perioperative or preoperative radiochemotherapy (RCTx) is nowadays standard for locally advanced esophageal cancer in Europe, as randomized studies have shown a significant survival benefit for patients with multimodal treatment. As responders and nonresponders have a significantly different prognosis, a response-based tailored preoperative treatment would be of utmost interest. An established method is a metabolic response evaluation by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). The level of metabolic response is known to be dependent on the localization, tumor entity and type of preoperative treatment. Association of FDG-PET with later response and prognosis was shown for absolute standardized uptake values (SUV) or a decrease of SUV levels before and after therapy but there are also contradictory findings in the literature and no prospective validation. However, neither time points nor cut-off for metabolic response evaluation have been defined so far. The most interesting approach seems to be early response monitoring during preoperative chemotherapy, which has shown promising results in prospective single center trials (MUNICON I/II) during chemotherapy of adenocarcinoma of the esophagogastric junction (AEG), but needs to be validated in prospective multicenter trails.

Prognostic factors for stereotactic radiosurgery-treated patients with cerebral metastasis: implications on randomised control trial design and inter-institutional collaboration.

INTRODUCTION: Defining key prognostic factors for patients with cerebral metastases who underwent stereotactic radiosurgery (SRS) treatment will greatly facilitate future clinical trial designs. METHODS: We adopted a two-phase study design where results from one cohort were validated in a second independent cohort. The exploratory analysis reviewed the survival outcomes of 1017 consecutive patients (with 3610 metastases) who underwent Gamma radiosurgery at the University of California, San Diego (UCSD)/San Diego Gamma Knife Center (SDGKC). Multivariate analysis was performed to identify prognostic factors. Results were validated using data derived from 2519 consecutive patients (with 17,498 metastases) treated with SRS at the Katsuta Hospital. RESULTS: For the SDGKC cohort, the median overall survival of patients following SRS was 7 months. Two year follow-up data were available for 85% of the patients. Multivariate analysis found that patient age, Karnofsky Performance Status, systemic cancer status, tumour histology, number of metastasis and cumulative tumour volume independently associated with overall survival (p<0.001). All statistical associations were validated by multivariate analysis of data derived from the Katsuta Hospital cohort. CONCLUSIONS: This is the first integrated study that defined prognostic factors for SRS-treated patients with cerebral metastases using an inter-institutional validation study design. The work establishes a model for collaborative interactions between large volume centers and provides prognostic variables that should be incorporated into future clinical trial design.

Prognostic value of histopathological regression in 850 neoadjuvantly treated oesophagogastric adenocarcinomas.

BACKGROUND: Recently, histopathological tumour regression, prevalence of signet ring cells, and localisation were reported as prognostic factors in neoadjuvantly treated oesophagogastric (junctional and gastric) cancer. This exploratory retrospective study analyses independent prognostic factors within a large patient cohort after preoperative chemotherapy including clinical and histopathological factors. METHODS: In all, 850 patients presenting with oesophagogastric cancer staged cT3/4 Nany cM0/x were treated with neoadjuvant chemotherapy followed by resection in two academic centres. Patient data were documented in a prospective database and retrospectively analysed. RESULTS: Of all factors prognostic on univariate analysis, only clinical response, complications, ypTNM stage, and R category were independently prognostic (P<0.01) on multivariate analysis. Tumour localisation and signet ring cells were independently prognostic only when investigator-dependent clinical response evaluation was excluded from the multivariate model. Histopathological tumour regression correlates with tumour grading, Laurén classification, clinical response, ypT, ypN, and R categories but was not identified as an independent prognostic factor. Within R0-resected patients only surgical complications and ypTNM stage were independent prognostic factors. CONCLUSIONS: Only established prognostic factors like ypTNM stage, R category, and complications were identified as independent prognostic factors in resected patients after neoadjuvant chemotherapy. In contrast, histopathological tumour regression was not found as an independent prognostic marker.