Improvement in the Assessment of Response to Preoperative Chemoradiotherapy for Rectal Cancer Using Magnetic Resonance Imaging and a Multigene Biomarker.

The response to preoperative chemoradiotherapy (PCRT) is correlated with oncologic outcomes in patients with locally advanced rectal cancer. Accurate prediction of PCRT response before surgery can provide crucial information to aid clinicians in further treatment planning. This study aimed to develop an evaluation tool incorporating a genetic biomarker and magnetic resonance imaging (MRI) to improve the assessment of response in post-CRT patients with locally advanced rectal cancer. A total of 198 patients who underwent PCRT followed by surgical resection for locally advanced rectal cancer between 2010 and 2016 were included in this study. Each patient's response prediction index (RPI) score, a multigene biomarker developed in our previous study, and magnetic resonance tumor regression grade (mrTRG) score were added to create a new predictive value for pathologic response after PCRT, called the combined radiation prediction value (cRPV). Based on the new value, 121 and 77 patients were predicted to be good and poor responders, respectively, showing significantly different cRPV values (p = 0.001). With an overall predictive accuracy of 84.8%, cRPV was superior to mrTRG and RPI for the prediction of pathologic chemoradiotherapy response (mrTRG, 69.2%; RPI, 77.3%). In multivariate analysis, cRPV was found to be the sole predictor of tumor response (odds ratio, 32.211; 95% confidence interval, 14.408-72.011; p = 0.001). With its good predictive value for final pathologic regression, cRPV may be a valuable tool for assessing the response to PCRT before surgery.

T2 gallbladder cancer shows substantial survival variation between continents and this is not due to histopathologic criteria or pathologic sampling differences.

Published data on survival of T2 gallbladder carcinoma (GBC) from different countries show a wide range of 5-year survival rates from 30-> 70%. Recently, studies have demonstrated substantial variation between countries in terms of their approach to sampling gallbladders, and furthermore, that pathologists from different continents apply highly variable criteria in determining stage of invasion in this organ. These findings raised the question of whether these variations in pathologic evaluation could account for the vastly different survival rates of T2 GBC reported in the literature. In this study, survival of 316 GBCs from three countries (Chile n = 137, South Korea n = 105, USA n = 74), all adequately sampled (with a minimum of five tumor sections examined) and histopathologically verified as pT2 (after consensus examination by expert pathologists from three continents), was analyzed. Chilean patients had a significantly worse prognosis based on 5-year all-cause mortality (HR: 1.89, 95% CI: 1.27-2.83, p = 0.002) and disease-specific mortality (HR: 2.41, 95% CI: 1.51-3.84, p < 0.001), compared to their South Korean counterparts, even when controlled for age and sex. Comparing the USA to South Korea, the survival differences in all-cause mortality (HR: 1.75, 95% CI: 1.12-2.75, p = 0.015) and disease-specific mortality (HR: 1.94, 95% CI: 1.14-3.31, p = 0.015) were also pronounced. The 3-year disease-specific survival rates in South Korea, the USA, and Chile were 75%, 65%, and 55%, respectively, the 5-year disease-specific survival rates were 60%, 50%, and 50%, respectively, and the overall 5-year survival rates were 55%, 45%, and 35%, respectively. In conclusion, the survival of true T2 GBC in properly classified cases is neither as good nor as bad as previously documented in the literature and shows notable geographic differences even in well-sampled cases with consensus histopathologic criteria. Future studies should focus on other potential reasons including biologic, etiopathogenetic, management-related, populational, or healthcare practice-related factors that may influence the survival differences of T2 GBC in different regions.

Amsterdam International Consensus Meeting: tumor response scoring in the pathology assessment of resected pancreatic cancer after neoadjuvant therapy.

Histopathologically scoring the response of pancreatic ductal adenocarcinoma (PDAC) to neoadjuvant treatment can guide the selection of adjuvant therapy and improve prognostic stratification. However, several tumor response scoring (TRS) systems exist, and consensus is lacking as to which system represents best practice. An international consensus meeting on TRS took place in November 2019 in Amsterdam, The Netherlands. Here, we provide an overview of the outcomes and consensus statements that originated from this meeting. Consensus (≥80% agreement) was reached on a total of seven statements: (1) TRS is important because it provides information about the effect of neoadjuvant treatment that is not provided by other histopathology-based descriptors. (2) TRS for resected PDAC following neoadjuvant therapy should assess residual (viable) tumor burden instead of tumor regression. (3) The CAP scoring system is considered the most adequate scoring system to date because it is based on the presence and amount of residual cancer cells instead of tumor regression. (4) The defining criteria of the categories in the CAP scoring system should be improved by replacing subjective terms including "minimal" or "extensive" with objective criteria to evaluate the extent of viable tumor. (5) The improved, consensus-based system should be validated retrospectively and prospectively. (6) Prospective studies should determine the extent of tissue sampling that is required to ensure adequate assessment of the residual cancer burden, taking into account the heterogeneity of tumor response. (7) In future scientific publications, the extent of tissue sampling should be described in detail in the "Materials and methods" section.

Shear Wave Elastography for Assessment of Steatohepatitis and Hepatic Fibrosis in Rat Models of Non-Alcoholic Fatty Liver Disease.

The purpose of this study was to evaluate shear wave elastography (SWE) as a method for determining the severity of non-alcoholic fatty liver disease (NAFLD) and the stage of hepatic fibrosis, as well as the major determinants of liver elasticity among the various histologic and biomolecular changes associated with NAFLD. Rat NAFLD models with various degrees of NAFLD severity were created and imaged using SWE. The explanted livers were subjected to histopathologic evaluation and RNA expression analysis. Among the histologic and biomolecular findings, the fibrosis stage and the collagen RNA level were significant independent factors associated with liver elasticity (p < 0.001). Liver elasticity was effective in detecting non-alcoholic steatohepatitis (NASH) and in determining fibrosis stage, and the corresponding areas under the receiver operating characteristic curves were 0.963 and 0.927-0.997, respectively. In conclusion, SWE is a potential non-invasive method for the detection of NASH and staging of hepatic fibrosis in patients with NAFLD.

Assessment of vascular endothelial growth factor in formalin fixed, paraffin embedded colon cancer specimens by means of a well-based reverse phase protein array.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a critical pro-angiogenic factor, found in a number of cancers, and a target of therapy. It is typically assessed by immunohistochemistry (IHC) in clinical research. However, IHC is not a quantitative assay and is rarely reproducible. We compared VEGF levels in colon cancer by IHC and a quantitative immunoassay on proteins isolated from formalin fixed, paraffin embedded tissues. RESULTS: VEGF expression was studied by means of a well-based reverse phase protein array (RPPA) and immunohistochemistry in 69 colon cancer cases, and compared with various clinicopathologic factors. Protein lysates derived from formalin fixed, paraffin embedded tissue contained measurable immunoreactive VEGF molecules. The VEGF expression level of well differentiated colon cancer was significantly higher than those with moderately and poorly differentiated carcinomas by immunohistochemistry (P = 0.04) and well-based RPPA (P = 0.04). VEGF quantification by well-based RPPA also demonstrated an association with nodal metastasis status (P = 0.05). In addition, the normalized VEGF value by well-based RPPA correlated (r = 0.283, P = 0.018). Furthermore, subgroup analysis by histologic type revealed that adenocarcinoma cases showed significant correlation (r = 0.315, P = 0.031) between well-based RPPA and IHC. CONCLUSIONS: The well-based RPPA method is a high throughput and sensitive approach, is an excellent tool for quantification of marker proteins. Notably, this method may be helpful for more objective evaluation of protein expression in cancer patients.