Search for a dark matter annihilation signal from the galactic center halo with H.E.S.S

A search for a very-high-energy (VHE; ≥100  GeV) γ-ray signal from self-annihilating particle dark matter (DM) is performed towards a region of projected distance r∼45-150  pc from the Galactic center. The background-subtracted γ-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) γ-ray instrument in the energy range between 300 GeV and 30 TeV shows no hint of a residual γ-ray flux. Assuming conventional Navarro-Frenk-White and Einasto density profiles, limits are derived on the velocity-weighted annihilation cross section (σv) as a function of the DM particle mass. These are among the best reported so far for this energy range and in particular differ only little between the chosen density profile parametrizations. In particular, for the DM particle mass of ∼1  TeV, values for (σv) above 3×10(-25)  cm(3) s(-1) are excluded for the Einasto density profile.

Outcomes of endoscopic papillectomy in elderly patients with ampullary adenoma or early carcinoma

Outcomes for 14 elderly (age ≥ 70 years) patients (79.4 ± 1.0 years) who underwent endoscopic papillectomy for ampullary tumors were compared with those of 22 younger (age < 70 years) patients (52.5 ± 1.9 years). There were no differences in procedural success (100%), bleeding (5/14 vs. 6/22), adenoma recurrence (0/14 vs. 2/22) and median survival (24.0 vs. 25.5 months) between the elderly and younger patients. In younger patients, although adenoma recurrences (n=2) were managed endoscopically, invasive adenocarcinomas (n=3) were treated by pancreatoduodenectomy. All elderly patients with invasive (T2) tumors (n=5) were not surgically fit and underwent successful palliation with further endoscopic resection and stenting. Whilst all younger patients survived, five elderly patients died but three of these deaths were not cancer-related. Advanced age, therefore, did not adversely influence the outcomes of endoscopic papillectomy, suggesting it may be a treatment of choice for elderly patients with ampullary tumors or early cancer who are deemed unfit for surgery.

Narrow-band imaging in the evaluation of villous morphology: a feasibility study assessing a simplified classification and observer agreement

BACKGROUND AND STUDY AIMS

To determine the utility of narrow-band imaging with optical magnification (NBI-Z) in the evaluation of villous morphology.

PATIENTS AND METHODS

Patients considered at risk of having celiac disease were invited. After standard endoscopy, they underwent further evaluation with NBI-Z which was digitally recorded. Targeted biopsies of each area videoed with NBI-Z were performed and tissue sent for histopathological analysis. Two expert endoscopists then selected the best representative videos (developmental phase). Next, 41 representative images of these videos were classified as follows: villous patterns present (N) or absent (A). Images showing absence of villi were then classified as cerebriform (C) or flat (F), corresponding to partial or total villous atrophy respectively. Three NBI-Z-naïve endoscopists then graded the videos. They underwent an interactive training session (learning phase) with video and images from a digital library before embarking on the actual assessment. To test for reproducibility, all videos were randomly reordered and graded again after a week.

RESULTS

Forty-one videos (10 celiac disease, 31 normal) from 21 patients (3 celiac disease, 18 normal) were analyzed. The overall sensitivity and specificity in correctly distinguishing the presence or absence of villi were 93.3% and 97.8% respectively, with interobserver and intraobserver agreement (kappa, κ) at 0.82 and 0.86. The sensitivity and specificity in differentiating partial from total villous atrophy were 83.3% and 100%, κ at 0.73 and 0.68 respectively.

CONCLUSIONS

Using a simplified classification, we demonstrated the feasibility of using NBI-Z to detect villous atrophy in patients presenting with suspected celiac disease.

Expression of ERα and Aromatase in MDA-MB-231 Tumors by HDAC Inhibitor Entinostat Leads to Growth Inhibition by Aromatase Inhibitor Letrozole

The treatment for hormone receptor-positive breast cancer has improved significantly since the development of aromatase inhibitors (AIs). Nevertheless, AIs are ineffective in estrogen receptor-negative (ER-) tumors, which comprise of approximately 25% of breast cancers and tend to be more aggressive. Studies have shown that repression of ER in these hormone receptor-negative tumors may be due to epigenetic modifications. The discovery of recruitment of histone deacetylase enzymes in gene silencing provides a rationale for inhibition of HDAC activity to release transcriptional repression as a potential therapeutic strategy. The objective of the present study was to express ERα and aromatase with HDACI treatment and thereby sensitize tumors to growth inhibition with aromatase inhibitors. In this study we used ER negative, hormone refractory MDA-MB-231 human breast cancer cells. Treatment with HDAC inhibitor entinostat led to upregulation of ERα, aromatase and its activity in a dose dependent manner in cells and xenografts. MDA-MB-231 xenografts were grown in ovariectomized female nude mice. Mice were inoculated with 2.5 X 106 cells per site subcutaneously. When the tumors reached 150 mm3, the mice were grouped into 4 groups (n=10), so that the mean tumor volume was not statistically different across groups (p=0.88). Tumor volumes were measured twice weekly. The mice in the letrozole group had a mean tumor growth rate (β = 0.023 ± 0.014) that was not statistically different (p=0.76) from that of the control group (β = 0.038 ± 0.007). Also, the growth rate of entinostat group (β = 0.034 ± 0.011) was not significantly lower than that of the control (p=0.33). However, the growth rate of entinostat plus letrozole group ((β = -0.003 ± 0.013) was significantly lower than that of the control (p=0.01), entinostat (p=0.03) and letrozole (p=0.049) groups. The combined treatment of entinostat plus letrozole was significantly more effective than either agent alone. In addition, the ability of this combination to inhibit migration in vitro was examined by wound healing assay. The combination of entinostat plus letrozole provides superior inhibition of migration (p&lt;0.001) compared to control, entinostat and letrozole alone. To test the efficacy of this combination in preventing the outgrowth of tumor foci in the lung, mice received an inoculation of 3 X 106 cells intravenously via the tail vein. They were treated three weeks later with entinostat alone, letrozole alone, or the combination. Mice were treated for six weeks, and then euthanized. Treatment with entinostat alone or letrozole was not significantly effective, but the combination resulted in a significantly reduced number of both visible and micrometastases (p=0.03) compared to no treatment (control) and the entinostat alone group. Thus, up-regulation of ERα and aromatase resulted in sensitization of tumors to significant inhibition of growth, cell migration and formation of micro-metastases by the aromatase inhibitor letrozole.Our results provide the basis for possible use of AIs in combination with HDAC inhibitors for the treatment of hormone refractory ERα negative breast cancer. This could open a new avenue for the management of ER- breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 401.

Spatial trends and historical deposition of mercury in eastern and northern Canada inferred from lake sediment cores

Recent and historical deposition of mercury (Hg) was examined over a broad geographic area from southwestern Northwest Territories to Labrador and from the U.S. Northeast to northern Ellesmere Island using dated sediment cores from 50 lakes (18 in midlatitudes (41-50 degrees N), 14 subarctic (51-64 degrees N) and 18 in the Arctic (65-83 degrees N)). Distinct increases of Hg overtime were observed in 76% of Arctic, 86% of subarctic and 100% of midlatitude cores. Subsurface maxima in Hg depositional fluxes (microg m(-2) y(-1)) were observed in only 28% of midlatitude lakes and 18% of arctic lakes, indicating little recent reduction of inputs. Anthropogenic Hg fluxes adjusted for sediment focusing and changes in sedimentation rates (deltaF(adj,F)) ranged from -22.9 to 61 microg m(-2) y(-1) and were negatively correlated (r = -0.57, P < 0.001) with latitude. Hg flux ratios (FRs; post-1990)/pre-1850) ranged from 0.5 to 7.7. The latitudinal trend for Hg deltaF(adj,F) values showed excellent agreement with predictions of the global mercury model, GRAHM for the geographic location of each lake (r = 0.933, P < 0.001). The results are consistent with a scenario of slow atmospheric oxidation of mercury, and slow deposition of reactive mercury emissions, declining with increasing latitude away from emission sources in the midlatitudes, and support the view that there are significant anthropogenic Hg inputs in the Arctic.

Results of a phase II multicenter study of minimally invasive esophagectomy (Eastern Cooperative Oncology Group Study E2202)

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Background: The incidence of esophagogastric adenocarcinoma (EAC) is increasing at an alarming rate in the United States. Definitive treatment may require a combination of surgery (esophagectomy), chemotherapy and radiation. Operative mortality rates after esophagectomy have been reported as high as 8–23% (NEJM 2003). Minimally invasive esophagectomy (MIE) may decrease morbidity and mortality. Previous single institution studies have demonstrated successful outcomes with MIE. The primary aim of this cooperative group protocol ECOG 2202 was to assess the feasibility of MIE in a multi-institutional setting. Methods: We conducted a prospective phase II trial with a two-stage design. Thirty-five patients entered the first stage, followed by an interim analysis. Next, the study continued to the second stage and full accrual. The primary endpoint was 30-day mortality. Secondary endpoints included complications, duration of intensive care unit (ICU) stay, lymph node (LN) count and clinical outcomes at 3 years. Results: We entered 106 patients (men 84%; women 22%; median age 64, range 36–83) into the study from 16 institutions in the United States (ECOG, CALGB, ACOSOG). Neoadjuvant chemotherapy was administered in 35 (33%) and radiation in 26 (25%). MIE was performed in 99 patients. Final pathology included high-grade dysplasia (n=11), and EAC (n=88). Complications included an overall 30-day mortality rate of 2% (2/106),. Other major complications included pneumonia (4.9%) and anastomotic leak (7.8%). Median ICU stay was 2 days; median LN count was 20. At a mean follow-up of 19 months, the estimated 3-year overall survival for the entire cohort was 50% (95% Confidence interval 35–65%). Stage specific survival was similar to open series. Conclusions: This phase II study demonstrates that MIE is safe and feasible in a multi-center trial, with low perioperative mortality rate and morbidity. Oncologic outcomes are similar to open esophagectomy. This is the first report of a multicenter trial of minimally invasive esophagectomy.

No significant financial relationships to disclose.