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.

Constraints on Minute-Scale Transient Astrophysical Neutrino Sources

High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E^{-2.5} neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to <5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is <10^{52.5}  erg. For a harder E^{-2.13} neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is <10^{52}  erg. A hypothetical population of transient sources has to be more common than 10^{-5}  Mpc^{-3}  yr^{-1} (5×10^{-8}  Mpc^{-3}  yr^{-1} for the E^{-2.13} spectrum) to account for the complete astrophysical neutrino flux.

Search for neutrinos from decaying dark matter with IceCube: IceCube Collaboration

With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino 'track' events from the Northern Hemisphere, while the second analysis uses 2 years of 'cascade' events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than10 28 s at 90% CL for dark matter masses above 10 TeV .

[Intrathoracic anastomotic leakage following esophageal and cardial resection : Definition and validation of a new severity grading classification]

BACKGROUND

Anastomotic leakage is still the most frequent cause of postoperative mortality following esophageal and cardial surgery. The German Advanced Surgical Study Group recommended that endoscopy should be the first diagnostic method if leakage is suspected. The German Surgical Endoscopy Association developed and validated a definition and severity classification of anastomotic leakage following esophageal and cardial resection.

MATERIAL AND METHODS

In 2010 the international study group on insufficiency published a definition and severity grading of anastomotic leakage following anterior resection of the rectum, which was validated in 2013. The severity of anastomotic leakage should be graded according to the impact on clinical management: type I requires only conservative management, type II requires interventional radiological or endoscopic treatment and type III requires surgical revision. In contrast to the rectal classification type III is divided into a category without (type IIIa) or with (type IIIb) conduit resection and diversion. The validation was carried out on a 10-year collective from the university hospitals in Heidelberg and Tübingen.

RESULTS

From 2006-2015 all 92 patients who developed an anastomotic leakage following esophageal and cardial resection were enrolled in the study. We found a significant increase in the length of stay in the intensive care unit (ICU) with increasing classification type (p < 0.0143). Furthermore, there was a significant correlation with the general classification of postoperative complications according to Clavien-Dindo as well as with mortality (p < 0.001).

DISCUSSION

Standardized parameters are the prerequisite to be able to compare the results between hospitals and studies. The validation of the suggested classification shows that the differentiation between the groups is substantiated by the correlation to the length of ICU stay, Clavien-Dindo and mortality and will therefore contribute to a better comparability of data on leakage following esophageal resection in the future.

MRI and sonography in Legg-Calvé-Perthes disease: clinical relevance of containment and influence on treatment

PURPOSE

The containment orientated treatment of Legg-Calvé-Perthes disease (LCPD) affected hip joints is broadly accepted in the literature. The prerequisite is early recognition of loss of containment. An often-used quantitative MRI containment parameter is the cartilaginous acetabulum-head-index (CAHI). Based on ultrasound (US), we analyzed the newly created 'femoral head extrusion angle' (HA) as a containment parameter in comparison with the CAHI in severe LCPD.

METHODS

In a prospective study with 40 children (mean age 5.8 years sd 2.3) with unilateral LCPD classified as Catterall group III/IV, we measured the CAHI versus HA to assess the containment of the femoral head. HA in US was determined by the tangent from the bony acetabular rim to the cartilaginous cranio-lateral femoral head.

RESULTS

The HA was significantly higher in LCPD-affected hip joints (25° sd 7°) than in healthy ones (13° sd 5°; p < 0.001). Correlation analysis of all hip joints revealed a significant correlation between HA and CAHI (r = -0.69; p < 0.001). Hip joints with a low CAHI indicating loss of containment showed a higher HA in sonography.

CONCLUSION

The results of our study suggest that the HA in US is a reliable containment parameter in severe LCPD with a HA > 22° defining a pathologic value. In comparison with the CAHI, HA measurement in ultrasound is easier than the assessment of various parameters to calculate an index. Frequent sonographical follow-up assessment in critical joints is an alternative if MRI is not available, helping to detect an impending loss of containment early enough.

LEVEL OF EVIDENCE

Level II.

Diagnosis of anti-laminin γ-1 pemphigoid by immunoblot analysis

BACKGROUND

Anti-laminin-γ1 (lam-γ1) pemphigoid, a recently described immunobullous disorder sharing immune serological features of bullous pemphigoid and epidermolysis bullosa acquisita (EBA), is characterized by the detection of serum IgG autoantibodies against the lam-γ1 chain, a 200 kDa heterotrimeric component of the dermal-epidermal junction (DEJ).

OBJECTIVE

The aim of the study was to develop an easy-to-perform and reliable assay for the serological detection of anti-lam-γ1 IgG autoantibodies. The clinical appearance alone is not sufficient to establish diagnosis of anti-lam-γ1 pemphigoid and rather requires immune serological evidence of (i) IgG reactivity against the dermal portion of salt-split human skin; (ii) exclusion of IgG against other components of the DEJ; and (iii) IgG reactivity with a 200 kDa protein of dermal extracts by immunoblot analysis (IB).

METHODS

The sera of 55 patients with anti-lam-γ1 pemphigoid were tested by IB with two recombinant heterotrimers, laminin 111 (lam-111) and laminin 421 (lam-421), as well as with a recombinant lam-γ1 chain monomer. Additionally, a total of 41 control sera from patients with EBA (n = 15), psoriasis vulgaris (PV; n = 14), and healthy controls (HC; n = 12) were tested.

RESULTS

Immunoblot analysis revealed a positive reactivity with lam-111 and/or lam-421 in 46/55 (84%) of anti-lam-γ1 pemphigoid sera. Moreover, 8/9 of the initially non-reactive sera were positive with the lam-γ1 monomer, leading to an overall sensitivity of 98.2%. Analyses of 41 control sera with the three lam-γ1 recombinants led to a specificity of 88%. Specifically, 3/15 EBA sera, 1/14 PV serum and 1/12 HC serum reacted with the lam-γ1 monomer while only the 3 EBA sera reacted with lam-421.

CONCLUSIONS

Here we show a novel two-step IB assay using the two recombinant laminin trimers and lam-γ1 chain monomer for the detection of anti-lam-γ1 serum IgG with high sensitivity and specificity. This assay will facilitate the diagnosis and further characterization of this disease.

[Gastric stump carcinoma: frequency, treatment, complications and prognosis]

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.