[Neuroendocrine neoplasia of the stomach : What is new?]

INTRODUCTION

Neuroendocrine Neoplasms are classified according to the new WHO classification in (1.) well differentiated neuroendocrine tumors G1 (NET G1, Ki67 ≤ 2 or mitosis count <2) and (2.) well differentiated neuroendocrine tumors G2 (NET G2, Ki67 3-20 or mitosis count 2-20) and (3.) poorly differentiated neuroendocrine carcinomas G3 (NEC G3, Ki67 > 20 or mitosis count >20).

MATERIAL AND METHODS

In this study 310 NENs of the Ludwig-Maximilians-University in Munich were reevaluated according to the new WHO classification.

RESULTS

7% of the analyzed NENs were presented as neoplasias of the stomach. In NENs of the stomach three distinct subtypes are recognized: (1) type 1 associated with autoimmune chronic atrophic gastritis (2) type 2, associated with multiple endocrine neoplasia (MEN1) and Zollinger-Ellison Syndrom; and (3) type 3, sporadic tumors.

DISCUSSION

Precursor lesions (i. e. hyperplasia of the ECL cells) are found in patients with hypergastrinaemia (type 1 and 2). This article should provide insights into the diagnosis of NENs of the stomach with emphasis on the new international standard.

[HER2 testing in gastric cancer - results of a German expert meeting]

Valid HER2 testing is essential for optimal therapy of patients with HER2 positive gastric cancer and the correct use of first-line treatment. While each breast cancer is routinely being tested for the HER2 status, HER2 testing in gastric cancer has still not become part of the routine and is often only done upon request by the therapist. An interdisciplinary German expert group took the challenges of HER2 testing in gastric cancer as an opportunity to address essential aspects and questions for the practical use of HER2 testing in this indication from the perspective of pathologists and therapists. The recommendations made in this manuscript reflect the consensus of all participants and correspond to their opinions and long-term experience.

Outcome according to KRAS-, NRAS- and BRAF-mutation as well as KRAS mutation variants: pooled analysis of five randomized trials in metastatic colorectal cancer by the AIO colorectal cancer study group

In this pooled analysis of metastatic colorectal cancer patients, mutations in KRAS, and BRAF were associated with inferior progression-free and overall survival compared with patients with non-mutated tumors. KRAS exon 2 mutation variants were associated with heterogeneous outcome compared with unmutated tumors with KRAS G12C and G13D being associated with rather poor survival.

Background

To explore the impact of KRAS, NRAS and BRAF mutations as well as KRAS mutation variants in patients with metastatic colorectal cancer (mCRC) receiving first-line therapy.

Patients and methods

A total of 1239 patients from five randomized trials (FIRE-1, FIRE-3, AIOKRK0207, AIOKRK0604, RO91) were included into the analysis. Outcome was evaluated by the Kaplan–Meier method, log-rank tests and Cox models.

Results

In 664 tumors, no mutation was detected, 462 tumors were diagnosed with KRAS-, 39 patients with NRAS- and 74 patients with BRAF-mutation. Mutations in KRAS were associated with inferior progression-free survival (PFS) and overall survival (OS) [multivariate hazard ratio (HR) for PFS: 1.20 (1.02–1.42), P = 0.03; multivariate HR for OS: 1.41 (1.17–1.70), P < 0.001]. BRAF mutation was also associated with inferior PFS [multivariate HR: 2.19 (1.59–3.02), P < 0.001] and OS [multivariate HR: 2.99 (2.10–4.25), P < 0.001]. Among specific KRAS mutation variants, the KRAS G12C-variant (n = 28) correlated with inferior OS compared with unmutated tumors [multivariate HR 2.26 (1.25–4.1), P = 0.001]. A similar trend for OS was seen in the KRAS G13D-variant [n = 71, multivariate HR 1.46 (0.96–2.22), P = 0.10]. More frequent KRAS exon 2 variants like G12D [n = 152, multivariate HR 1.17 (0.86–1.6), P = 0.81] and G12V [n = 92, multivariate HR 1.27 (0.87–1.86), P = 0.57] did not have significant impact on OS.

Conclusion

Mutations in KRAS and BRAF were associated with inferior PFS and OS of mCRC patients compared with patients with non-mutated tumors. KRAS exon 2 mutation variants were associated with heterogeneous outcome compared with unmutated tumors with KRAS G12C and G13D (trend) being associated with rather poor survival.

CEA response is associated with tumor response and survival in patients with KRAS exon 2 wild-type and extended RAS wild-type metastatic colorectal cancer receiving first-line FOLFIRI plus cetuximab or bevacizumab (FIRE-3 trial)

BACKGROUND

To examine the relation of carcinoembryonic antigen (CEA) response with tumor response and survival in patients with (K)RAS wild-type metastatic colorectal cancer receiving first-line chemotherapy in the FIRE-3 trial comparing FOLFIRI plus cetuximab versus FOLFIRI plus bevacizumab.

PATIENTS AND METHODS

CEA response assessed as the percentage of CEA decrease from baseline to nadir was evaluated for its association with tumor response and survival. Receiver operating characteristic analysis revealed an optimal cut-off value of 75% using the maximum of sensitivity and specificity for CEA response to discriminate CEA responders from non-responders. In addition, the time to CEA nadir was calculated.

RESULTS

Of 592 patients in the intent-to-treat population, 472 were eligible for analysis of CEA (cetuximab arm: 230 and bevacizumab arm: 242). Maximal relative CEA decrease (%) significantly (P = 0.003) differed between the cetuximab arm (median 83.0%; IQR 40.9%-94.7%) and the bevacizumab arm (median 72.3%; IQR 26.3%-91.0%). In a longitudinal analysis, the CEA decrease occurred faster in the cetuximab arm and was greater than in the bevacizumab arm at all evaluated time points until 56 weeks after treatment start. CEA nadir occurred after 3.3 months (cetuximab arm) and 3.5 months (bevacizumab arm), (P = 0.49). In the cetuximab arm, CEA responders showed a significantly longer progression-free survival [11.8 versus 7.4 months; hazard ratio (HR) 1.53; 95% Cl, 1.15-2.04; P = 0.004] and longer overall survival (36.6 versus 21.3 months; HR 1.73; 95% Cl, 1.24-2.43; P = 0.001) than CEA non-responders. Analysis of extended RAS wild-type patients revealed similar results.

CONCLUSION

In the FIRE-3 trial, CEA decrease was significantly faster and greater in the cetuximab arm than in the bevacizumab arm and correlated with the prolonged survival observed in patients receiving FOLFIRI plus cetuximab.

CLINICAL TRIALS NUMBER

NCT00433927 (ClinicalTrials.gov); AIO KRK0306 FIRE-3.

[Molecular pathology of colorectal cancer]

In recent years, several predictive and prognostic biomarkers have been established in colorectal cancer (CRC). The RAS-mutation status is widely applied in the daily routine diagnostic as predictive biomarker for treatment with EGFR-inhibitors. A BRAF- mutation has no predictive value in this context. The detection of high-grade microsatellite instability (MSI-H) is a predictive biomarker for response to 5-Fluoruracil-monotherapy. Prognostic biomarkers in CRC are the MSI-status and the mutational status of BRAF. According to the current WHO classification poorly and undifferentiated CRC and MSI-associated special morphological subtypes are molecular graded depending on their MSI-status. The detection of a BRAF-mutation in the context of microsatellite stability (MSS) is associated with a very poor prognosis and thus represents the most aggressive molecular subtype of CRC. In patients with positive Bethesda criteria a stepwise immunohistochemical and molecular diagnostic scheme is proposed.

Influence of mRNA expression of epiregulin and amphiregulin on outcome of patients with metastatic colorectal cancer treated with 5-FU/LV plus irinotecan or irinotecan plus oxaliplatin as first-line treatment (FIRE 1-trial)

Our aim was to investigate the impact of EREG and AREG mRNA expression (by RT-qPCR) in patients with metastatic colorectal cancer (mCRC). In addition, epidermal growth factor receptor (EGFR) expression (by immunohistochemistry) as well as RAS-and PIK3CA-mutations (by pyrosequencing) were assessed. Tumors of 208 mCRC patients receiving 5-fluorouracil/leucovorin plus irinotecan (FUFIRI) or irinotecan plus oxaliplatin (mIROX) within the FIRE-1 trial were analyzed for mutations. Molecular characteristics were correlated with response, progression-free survival (PFS), overall survival (OS). mRNA expression was evaluated using ROC-analysis in 192 tumors (AREG high n = 31 vs. low n = 161; EREG high n = 89 vs. low n = 103). High versus low AREG expression was associated with PFS of 10.0 versus 8.0 months (HR = 0.62, 95% CI: 0.402-0.940, p = 0.03) and OS of 24.6 versus 18.7 months (HR = 0.72, 95% CI: 0.476-1.078, p = 0.11). High versus low EREG expression correlated with prolonged PFS (9.4 vs. 6.8 months, HR = 0.62, 95% CI: 0.460-0.846, p = 0.002) and OS (25.8 vs. 15.5 months, HR = 0.48, 95% CI: 0.351-0.657, p < 0.001). The positive prognostic effect of high EREG expression was confirmed in a multivariate analysis and was neither affected by EGFR expression nor by mutations of RAS- and PIK3CA-genes. EREG expression appears as an independent prognostic marker in patients with mCRC receiving first-line irinotecan-based chemotherapy.

Restructuring of the electrical double layer in ionic liquids upon charging

We have investigated the electrical double layer (EDL) structure at an interface between ionic liquid (IL) and charged surface using molecular dynamics simulations. We show that for three different models of ILs the EDL restructuring, driven by surface charging, can be rationalized by the use of two parameters--renormalized surface charge (κ) and charge excess in the interfacial layers (λ). Analysis of the relationship between the λ and κ parameters provides new insights into mechanisms of over-screening and charge-driven structural transitions in the EDL in ionic liquids. We show that the restructuring of the EDL upon charging in all three studied systems has two characteristic regimes: (1) transition from the bulk-like (κ(Ion) = 0) to the multilayer structure (κ(Ion) ≈ 0.5) through the formation of an ionic bilayer of counter- and co-ions; and (2) transition from the multilayer (κ(Ion) ≈ 0.5) to the crowded (κ(Ion) > 1) structure through the formation of a monolayer of counter-ions at κ(Ion) = 1.

Evasive behaviours of female dusky dolphins (Lagenorhynchus obscurus) during exploitative scramble competition

When males engage in scramble competition, are females non-evasive recipients of male coercion or evasive? Small groups of male dusky dolphins (Lagenorhynchus obscurus) engage in exploitative (non-interference) scramble competition for access to oestrous females near Kaikoura, New Zealand. We conducted behavioural sequence analyses of videos of 48 mating groups with continuous records and focal individual follows of females. We determined (1) the frequency and type of behaviours (non-evasive vs. evasive), (2) the variation in simple transition probabilities of behaviours leading to a copulatory position associated with female resistance and non-resistance and (3) the variation in female responses to male behaviours throughout focal follows. Females exhibited frequent active evasive manoeuvers following male behaviours. Copulation sequences were highly variable and most complex when terminated by females. Females altered responses to male signals, one aspect of mate choice potentially favouring male endurance.

[Colorectal carcinoma in consideration of the new German S3 guideline 2013]

In the current German S3 guidelines for colorectal carcinoma (CRC), morphologically based tumor grading is extended by molecular grading for poorly differentiated and undifferentiated carcinomas, as well as for special morphological subtypes. These CRC are classified as low-grade when microsatellite instability (MSI) is found. In routine diagnostics, immunohistochemistry for hMLH1 and hMSH2, capturing MSI-CRC with high sensitivity and specificity, can be used as an inexpensive substitute for molecular MSI-testing. In patients with positive Bethesda criteria, a stepwise immunohistochemical and molecular diagnostic scheme is proposed. The detection of a BRAF mutation in tumors with hMLH1 loss allows distinguishing between sporadic and HNPCC-associated MSI-CRC. For rectal cancer the residual tumor classification (R-status) is completed by the circumferential resection margin classification (CRM).

Left-sided primary tumors are associated with favorable prognosis in patients with KRAS codon 12/13 wild-type metastatic colorectal cancer treated with cetuximab plus chemotherapy: an analysis of the AIO KRK-0104 trial

Purpose

AIO KRK-0104 investigated first-line therapy of metastatic colorectal cancer (mCRC) with cetuximab, capecitabine and irinotecan versus cetuximab, capecitabine and oxaliplatin. This analysis investigated the impact of primary tumor location on outcome of patients.

Patients and methods

Left-sided primary tumors were defined as tumors from rectum to left flexure, while tumors in the remaining colon were regarded right sided. Overall survival (OS), progression-free survival (PFS) and response rate were correlated with primary tumor location. A Cox regression model was used to evaluate interaction between primary tumor location and KRAS mutation.

Results

Of 146 patients of the AIO KRK-0104 trial, 100 patients presented left-sided (of those 68 KRAS codon 12/13 wild-type) and 46 patients right-sided primary tumors (of those 27 KRAS codon 12/13 wild-type). Left-sided tumors were associated with significantly longer OS (p = 0.016, HR = 0.63) and PFS (p = 0.02, HR = 0.67) as compared to right-sided tumors. These effects were present in the KRAS codon 12/13 wild-type population (HR OS: 0.42; HR PFS: 0.54), while no impact of primary tumor location was evident in patients with KRAS codon 12/13 mutant tumors (HR OS: 1.3; HR PFS: 1.01). A significant interaction of KRAS status and primary tumor location concerning OS and PFS was observed.

Conclusion

Our findings suggest that primary tumor location and KRAS codon 12/13 mutational status interact on the outcome of patients with mCRC receiving cetuximab-based first-line therapy. Left-sided primary tumor location might be a predictor of cetuximab efficacy.

Endoscopic sinus surgery training courses: benefit and problems - a multicentre evaluation to systematically improve surgical training

BACKGROUND

The aim of this multicentre study was to systematically analyse the strengths and weaknesses in the surgical training for endoscopic sinus surgery (ESS) and identify measures that may improve training.

METHODOLOGY

Using a structured questionnaire, 133 participants of ESS courses in seven centres in Germany, Switzerland and Australia were asked about their experiences during their dissection courses and how they perceived their course could be improved.

RESULTS

Gaining confidence in handling of instruments and endoscopes was only a problem for participants with little experience in ESS. The majority of the participants, independent from their level of training, considered infundibulotomy and anterior ethmoidectomy as the easiest dissection steps, whilst surgery of the frontal sinus posed a considerable challenge for many surgeons even those with a higher level of training. Participants with and without ESS experience thought that emphasis on anatomy was the most important improvement that could be made during their surgical training. Virtually all participants stated that the course improved their anatomical knowledge, their surgical skills and their confidence when performing ESS.

CONCLUSIONS

ESS dissection courses are considered beneficial by surgical trainees. Participants felt that more emphasis on sinus anatomy in conjunction with private study is essential to maximize their skills in surgical dissection. For beginners with ESS, an infundibulotomy and anterior ethmoidectomy were thought to be the best initial procedures to help develop endoscopic surgical skills.