The role of neoadjuvant and adjuvant treatment for adenocarcinoma of the upper gastrointestinal tract

Both locally advanced adenocarcinoma of the stomach and gastro-esophageal junction are associated with poor prognosis due to the lack of effective treatment. Recently multimodal treatment consisting of neoadjuvant chemotherapy in combination with radiotherapy is reported to improve survival when compared to surgery alone. Neoadjuvant therapy in these locally advanced tumors allows for early tumor responses and the extent of tumor regression that can be achieved is considered a significant prognostic factor. This, in turn, increases the resectability of these tumors. Also due to the high frequency of lymph node metastasis, patients with locally advanced adenocarcinoma should undergo a D2 lymphadenectomy. Postoperative chemoradiation and perioperative chemotherapy have been studied in gastric adenocarcinomas and showed a survival benefit. However, the surgical techniques used in these trials are no longer considered to be standard by today's surgical practice. In addition, there are no standard recommendations for adjuvant chemotherapy or chemoradiation after R0 resection and adequate lymph node dissection

MicroRNA-199b-5p Impairs Cancer Stem Cells through Negative Regulation of HES1 in Medulloblastoma

BACKGROUND: Through negative regulation of gene expression, microRNAs (miRNAs) can function in cancers as oncosuppressors, and they can show altered expression in various tumor types. Here we have investigated medulloblastoma tumors (MBs), which arise from an early impairment of developmental processes in the cerebellum, where Notch signaling is involved in many cell-fate-determining stages. MBs occur bimodally, with the peak incidence seen between 3-4 years and 8-9 years of age, although it can also occur in adults. Notch regulates a subset of the MB cells that have stem-cell-like properties and can promote tumor growth. On the basis of this evidence, we hypothesized that miRNAs targeting the Notch pathway can regulated these phenomena, and can be used in anti-cancer therapies. METHODOLOGY/PRINCIPAL FINDINGS: In a screening of MB cell lines, the miRNA miR-199b-5p was seen to be a regulator of the Notch pathway through its targeting of the transcription factor HES1. Down-regulation of HES1 expression by miR-199b-5p negatively regulates the proliferation rate and anchorage-independent growth of MB cells. MiR-199b-5p over-expression blocks expression of several cancer stem-cell genes, impairs the engrafting potential of MB cells in the cerebellum of athymic/nude mice, and of particular interest, decreases the MB stem-cell-like (CD133+) subpopulation of cells. In our analysis of 61 patients with MB, the expression of miR-199b-5p in the non-metastatic cases was significantly higher than in the metastatic cases (P = 0.001). Correlation with survival for these patients with high levels of miR-199b expression showed a positive trend to better overall survival than for the low-expressing patients. These data showing the down-regulation of miR-199b-5p in metastatic MBs suggest a potential silencing mechanism through epigenetic or genetic alterations. Upon induction of de-methylation using 5-aza-deoxycytidine, lower miR-199b-5p expression was seen in a panel of MB cell lines, supported an epigenetic mechanism of regulation. Furthermore, two cell lines (Med8a and UW228) showed significant up-regulation of miR-199b-5p upon treatment. Infection with MB cells in an induced xenograft model in the mouse cerebellum and the use of an adenovirus carrying miR-199b-5p indicate a clinical benefit through this negative influence of miR-199b-5p on tumor growth and on the subset of MB stem-cell-like cells, providing further proof of concept. CONCLUSIONS/SIGNIFICANCE: Despite advances in our understanding of the pathogenesis of MB, one-third of these patients remain incurable and current treatments can significantly damage long-term survivors. Here we show that miR-199b-5p expression correlates with metastasis spread, identifying a new molecular marker for a poor-risk class in patients with MB. We further show that in a xenograft model, MB tumor burden can be reduced, indicating the use of miR199b-5p as an adjuvant therapy after surgery, in combination with radiation and chemotherapy, for the improvement of anti-cancer MB therapies and patient quality of life. To date, this is the first report that expression of a miRNA can deplete the tumor stem cells, indicating an interesting therapeutic approach for the targeting of these cells in brain tumors

Do insulin-like growth factor associated proteins qualify as a tumor marker? results of a prospective study in 163 cancer patients*

Abstract Objective Insulin-like growth factor (IGF)-1, -2 and Insulin like growth factor binding proteins (IGFBP) are involved in the proliferation and differentiation of cells. It has never been evaluated, if the IGF-system can serve as a tumor marker in neoplasms. Methods In our prospective study 163 patients with colorectal cancer (22), prostate cancer (21), head and neck tumors (17), lymphomas (20), lung cancer (34) and other entities (49) were analysed for their IGF and IGFBP serum levels at the beginning and the end of radiotherapy and compared to 13 healthy people. Subgroups of patients with local tumor disease versus metastatic disease, primary and recurrent therapy and curative versus palliative therapy were compared. Results The serum levels of IGF-2 were significantly elevated in patients with prostate and colorectal cancer. However, sensitivity and specificity were only 70%. IGFBP-2 serum levels were elevated in patients with head and neck tumors. Again sensitivity and specificity were only 73%. A difference between local disease and metastatic disease could not be found. A difference between IGF serum levels before and after radiotherapy could not be detected. Conclusion The IGF-system cannot serve as a new tumor marker. The detected differences are very small, sensitivity and specificity are too low. IGF measurement is not useful for the evaluation of the success of radiotherapy in malignancies.</p

Clinical validation of the automated characterization of cone size and center in keratoconic corneas

PURPOSE: To evaluate an automated method for detecting the cone shape characteristics and to assess the cornea specialists' subjective variability of these measures using different maps. METHODS: Topographic images of the anterior and posterior surface of each eye were presented to 12 clinicians in two different types of map: Tangential curvature and relative elevation to the best-fit sphere. They were asked to mark the cone center and its boundaries in the two maps without knowing that they belonged to the same patient. The results between the maps were compared to assess the subjective variability dependent on the map type and the automated method was compared against both estimations to assess its accuracy. RESULTS: Considering the results of anterior and posterior surfaces, there was low agreement between the cone center estimations using different types of maps for 10 of the 12 cases (P .05). There was high variability, up to 55%, among clinicians' estimations of the cone area. The results of the automated method were within the range of the expert's estimations. CONCLUSIONS: An objective, mathematically derived method of determining morphological dimensions of the cone was consistent with clinicians' evaluations. Although there was high variability among the experts' subjective estimates, which were highly influenced by the type of map, the objective method provided a reliable evaluation of the keratoconus shape independent of maps or color scale