[Standardized and quality-assured predictive PD-L1 testing in the upper gastrointestinal tract. German version]

As a result of the high approval dynamics and the growing number of immuno-oncological therapy concepts, the complexity of therapy decisions and control in the area of carcinomas of the esophagus, gastroesophageal junction and stomach is constantly increasing. Since the treatment indication for PD‑1 inhibitors that are currently approved in the European Union is often linked to the expression of PD-L1 (programmed cell death-ligand 1), the evaluation of tissue-based predictive markers by the pathologist is of crucial importance for treatment stratification. Even though the immunohistochemical analysis of the PD-L1 expression status is one of the best studied, therapy-relevant biomarkers for an immuno-oncological treatment, due to the high heterogeneity of carcinomas of the upper gastrointestinal tract, there are challenges in daily clinical diagnostic work with regard to implementation, standardization and interpretation of testing. An interdisciplinary group of experts from Germany has taken a position on relevant questions from daily pathological and clinical practice, which concern the starting material, quality-assured testing and the interpretation of pathological findings, and has developed recommendations for structured reporting.

Standardized and quality-assured predictive PD-L1 testing in the upper gastrointestinal tract

As a result of the high approval dynamics and the growing number of immuno-oncological concepts, the complexity of treatment decisions and control in the area of cancers of the esophagus, gastroesophageal junction and stomach is constantly increasing. Since the treatment indication for PD-1 inhibitors that are currently approved in the European Union is often linked to the expression of PD-L1 (programmed cell death-ligand 1), the evaluation of tissue-based predictive markers by the pathologist is of crucial importance for treatment stratification. Even though the immunohistochemical analysis of the PD-L1 expression status is one of the best studied, therapy-relevant biomarkers for an immuno-oncological treatment, due to the high heterogeneity of carcinomas of the upper gastrointestinal tract, there are challenges in daily clinical diagnostic work with regard to implementation, standardization and interpretation of testing. An interdisciplinary group of experts from Germany has taken a position on relevant questions from daily pathological and clinical practice, which concern the starting material, quality-assured testing and the interpretation of pathological findings, and has developed recommendations for structured reporting.

Implications of crop model ensemble size and composition for estimates of adaptation effects and agreement of recommendations

Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.

Cecal Resection with Bipolar Sealing Devices in a Rat Model

Background: Bipolar sealing devices are routinely used to seal blood vessels. The aim of the study is to evaluate the feasibility and safety of colonic sealing with the use of the bipolar energy devices in rats as model for experimental appendectomy. Methods: Seventy-five male Wistar rats underwent a cecal resection with four different bipolar sealing devices or a linear stapler. The harvesting procedure was performed immediately or at postoperative day (POD) 7. The sealing front bursting pressure (BP) was measured in both groups. At POD7, the resection line was clinically examined and the hydroxyproline (HDP) levels were determined. Hematoxylin and Eosin (H&E) staining was used for histopathological evaluation of the sealing front as well. Results: There was no mortality and no insufficiency. The BPs between the bipolar sealing devices showed no statistical differences. The early phase of the seal (POD 0) provides a low BP with an 30.8% increase until POD 7. The BPs in the stapler group showed significant better values. The hydroxyproline levels did not differ statistically between the groups. Histopathologically, there were more signs of ischemic necrosis in the stapler group than in the sealing devices groups. Conclusion: The resection and sealing of the cecum as an experimental appendectomy model with the use of bipolar energy devices proved feasible and safe in rats. The different energy devices in this study produce comparable results. To justify clinical practice in humans, several studies on the underlying mechanisms of early stage wound healing are needed.

[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.

[Sexually transmitted infections as a cause for solid rectal pseudo tumors]

Two cases of symptomatic proctitis with rectal tumors suspicious for malignancy are presented. A florid regenerative proctitis was shown in the histological examination. In both cases a sexually transmitted infection (STI) was causing the symptoms. In rare cases STIs present as pseudo tumors mimicking malignancy in clinical examination and endoscopic/radiological analysis. A close collaboration between gastroenterologist and pathologist is necessary for a correct diagnosis and to prevent unnecessary surgical treatment.

[In situ hybridization in clinical pathology. Significance of polysomy 17 for HER2 determination and genetic tumor heterogeneity in breast cancer]

The introduction of total genome sequencing led to the confirmation that tumors show substantial genetic heterogeneity. This phenomenon, which describes the presence of different genetic cell clones within a tumor also complicates the diagnostics of HER2. This article gives a review of new knowledge on polysomy 17 and genetic tumor heterogeneity in connection with HER2 determination of breast cancer.

Triple-Negative Breast Cancers Express Receptors for GnRH and Can Be Effectively Targeted by the Orally Active GnRH-Antagonist AEZS 115

IntroductionAEZS-115* is an orally active peptidomimetic antagonist of GnRH, which has been shown to block the pituitary GnRH receptor. In various tumors an autocrine growth promoting loop consisting of GnRH secreted by the malignant cells and tumoral GnRH receptors has been described. The current study investigates the expression of GnRH-receptors in tumor samples of triple-negative breast cancers and evaluates the anti-tumor activity of the GnRH antagonist AEZS 115 in in vitro models of triple negative breast cancers.Study design17 human samples of triple negative breast cancers were tested for GnRH-receptor expression by immunohistochemistry. Human triple negative breast cancer cell lines MDA-MB 468, HCC 1806 and HCC 1937 were analyzed for GnRH receptor expression by immunocytochemistry and western blot analysis. These cell lines were incubated with increasing concentrations of AEZS-115, peptidic GnRH-antagonist Cetrorelix and GnRH-agonist Triptorelin (1, 10, 100 µm) for 48 hours and the number of viable cells was determined by crystal violet staining as well as by ATP-dependent luminometric assay.ResultsPositive staining for GnRH-receptors was detected in all tumor samples (2 high, 12 moderate, 3 weak). Cell lines MDA MB 468, HCC 1806 and HCC 1937 expressed GnRH receptors as demonstrated by immunocytochemistry and western blot analysis. GnRH-antagonist AEZS 115 dose dependently inhibited growth of all three cell lines, while GnRH-agonist Triptorelin and peptidic GnRH antagonist Cetrorelix showed marginal growth inhibition. At 10 µm AEZS-115 inhibited cell growth by 40-60%, at 100 µm growth inhibition was 60-80%. These results obtained by crystal violet staining were confirmed by additional luminometric evaluation of the ATP content after treatment with the respective substances.ConclusionsThe orally active, peptdidomimetic GnRH antagonist AEZS-115 showed substantial anti-tumor activity in these cell lines, while GnRH-agonist Triptorelin and peptidic antagonist Cetrorelix showed only minor growth inhibition. Thus, in triple negative breast cancers the peptidomimetic antagonist AEZS-115 was more potent than the decapeptide Cetrorelix. This finding could be explained by atypical GnRH-receptors on tumor tissue to which the different GnRH-antagonists might bind with different affinity. Due to high receptor expression the GnRH receptor is a promising target in triple negative breast cancers. The good antitumor-activity makes AEZS-115 a promising candidate for in vivo studies in this tumor entity.*Aeterna Zentaris GmbH, Frankfurt/M, Germany.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6108.

Influence of expression of EGFR and PTEN on outcome in patients with primary glioblastoma treated with standard radiochemotherapy and cetuximab: Interim analysis from the GERT-Protocol

2050

Background: The epidermal growth factor receptor (EGFR) is commonly amplified, overexpressed, and mutated in glioblastoma (GBM). Anti-EGFR treatments have shown to be associated with EGFR deletion mutant variant III (EGFRvIII) expression in presence of PTEN expression, suggesting a prognostic role of EGFRvIII expression. We determined molecular biomarkers and correlated these with outcome in the GERT trial. Methods: To date, 39 patients were treated within the GERT protocol (Combs SE et al., 2006) evaluating radiochemotherapy (RCHT) with temozolomide (TMZ) and weekly CTX. Pretreatment paraffin-embedded tumor tissue of 32 patients was available for molecular analysis. Twenty-three patients were male, 9 were female. Median age was 49 years. We analyzed amplification of EGFR, expression of EGFR, EGFRvIII, the tumor-suppressor PTEN and O(6)-methylguanine DNA methyltransferase (MGMT) gene promoter methylation. Results: Median follow-up was 12 months. Overall survival (OS) at 12 and 24 months was 89% and 42%. Progression-free survival (PFS) was 76% and 45% at 6 and 12 months, respectively. MGMT promoter hypermethylation was detected in 16/32 tumours. Methylated MGMT did not impact PFS or OS (p = 0.48 and p = 0.08). Data on EGFR copy number of 31/32 tumors showed EGFR gene amplification in 11 tumors. EGFR protein expression was found in 23/32 patients. EGFR-amplification did not impact PFS or OS (p = 0.56, p = 0.3). Patients with EGFR expression showed longer PFS (p = 0.05), but unaltered OS (p = 0.06). EGFRvIII was seen in 5/32 patients, only in tumors with EGFR amplification. Expression of EGFRvIII did not influence PFS (p = 0.26) or OS (p = 0.09). Reduced PTEN (22/32) did not influence PFS or OS (p = 0.27, p = 0.85). Outcome was not associated with coexpression of EGFRvIII and PTEN (n = 5); coexpression of EGFR and PTEN (n = 13) significantly influenced PFS (p = 0.005), but not OS (p = 0.10). Conclusions: Expression of EGFR, and coexpression of EGFR/PTEN is associated with significant increase in PFS after RCHT with TMZ and CTX. EGFR-amplification, reduction of PTEN expression and expression of EGFRvIII did not impact PFS nor OS. Randomized data in the primary treatment of GBM might help identify patients for anti-EGFR therapies.

[Table: see text]

TRAIL-mediated apoptosis in malignant glioma cells is augmented by celecoxib through proteasomal degradation of survivin

Celecoxib is a cyclooxygenase 2-selective nonsteroidal anti-inflammatory drug (NSAID) that exhibited therapeutic activity in cancer. In this study three malignant glioma, U87-MG, U251 and A172, were treated with celecoxib, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or the combination of both. Single treatment with celecoxib (25-100muM) for 24h resulted in a concentration-dependant decrease of cellular viability in U87-MG, U251 and A172. Combining subtoxic concentrations of celecoxib with TRAIL strongly increased cell death in human malignant glioma cells. After 8h treatment with celecoxib we found down-regulation of the inhibitor of apoptosis protein survivin that was mediated by proteasomal degradation. In addition, over-expression of survivin not only attenuated celecoxib-induced cytotoxicity but also cytotoxicity induced by the combination of celecoxib and TRAIL. Taken together, in malignant glioma survivin is a key regulator in celecoxib- and TRAIL-celecoxib-mediated cell death.

Sinushistiozytose mit massiver Lymphadenopathie (Rosai-Dorfman-Erkrankung)

Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare, painless lymphoproliferative disorder of unknown origin with a usually benign course. About 40% of the patients show an extranodal involvement with skin being the most common site in 27% of these patients. We describe a patient with widespread disease involving the respiratory tract, kidneys and skin. Histopathology revealed the characteristic features of SHML with emperipolesis and immunohistochemical positivity of histiocytes for S100 and macrophage-associated antigens.

[Type I neurofibromatosis and megadolichobasilar artery]

Intracranial vascular malformations are rare but tend to appear more frequently than usual in patients with type I neurofibromatosis (NFI). Aneurysms of the basilar artery have been described four times so far. We report two cases of 51- and 62-year-old patients with type I neurofibromatosis who showed long fusiform dilation of the basilar artery. Clinically both patients presented with locked-in syndrome and died 15 and 11 days after admission. The diagnosis was confirmed by autopsy. These are the first published cases of locked-in syndrome following thrombosis of a megadolichobasilar artery in association with neurofibromatosis I. Our results show that cerebral vascular malformations are found more frequently than random chance would predict in patients with NF I.

Central HER2 IHC and FISH analysis in a trastuzumab (Herceptin) phase II monotherapy study: assessment of test sensitivity and impact of chromosome 17 polysomy

AIMS

To investigate the correlation between centrally assessed human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH) results and response to treatment of patients with metastatic breast cancer enrolled in a first-line, phase II, open-label, 3-weekly trastuzumab (Herceptin) monotherapy trial (WO16229).

METHODS

Samples from participants in the WO16229 trial were collected and tumour HER2 status determined by IHC and FISH. HER2 test results were interpreted according to manufacturers' test kit protocols. Responders were defined as patients showing either partial or complete responses.

RESULTS

Response data were available for 103/105 patients; centrally confirmed HER2 status was available for 95 patients. Intra-laboratory concordance for central IHC and FISH results was 93%. Complete responses were seen in two patients; their samples were IHC 3+ and FISH positive. Partial responses were seen in 17 patients; all were IHC 3+ and 14 were FISH positive. IHC and FISH showed 100% and 84.2% sensitivity, respectively, in determining response to trastuzumab. Polysomy was observed in 27% of patients; six responded to trastuzumab treatment. All six responders showed HER2 overexpression (IHC 3+) and HER2 gene amplification; two were FISH negative due to chromosome 17 polysomy.

CONCLUSIONS

HER2 determination by IHC and FISH correlates with clinical response data in the WO16229 trial with high concordance of IHC and FISH results. Polysomy is the major cause of response in FISH-negative cases; polysomic cases should be retested by strictly standardised IHC.

[Receptors for luteinizing hormone releasing hormone expressed on melanoma, renal cell carcinoma and non Hodgkin lymphoma can be used for targeted chemotherapy with cytotoxic luteinizing hormone releasing hormone analogues]

AIMS

Cytotoxic luteinizing hormone releasing hormone (LHRH) analogues AN-152 and AN-207 consist of [D-Lys6] LHRH linked to doxorubicin or its hyperactive derivate AN-201 and bind with high affinity to LHRH receptors. We evaluated the use of AN-207 and AN-201 in a nude mice model. In order to provide a rationale for the possible use of cytotoxic LHRH analogues in different malignancies we investigated the expression of LHRH-R in human renal cell carcinoma (RCC), melanoma and non Hodgkin's Lymphoma (NHL).

METHODS

The expression of LHRH-R was examined in surgically removed human specimens of primary tumours and metastases from 37 RCC, 19 melanomas and 17 NHLs. In addition, human tumour cell lines expressing LHRH receptors were transplanted into nude mice and anti-tumour efficacy and systemic toxicity of AN-207 and its cytotoxic radical AN-201 were compared in various experiments.

RESULTS

Positive staining for LHRH receptors was found in all of the RCC (37/37) and the melanoma specimens (19/19) as well as in 100% (10/10) of the NHLs. In in vivo experiments AN-207 significantly inhibited tumour growth while the cytotoxic radical alone was ineffective. Furthermore, side effects were reduced with targeted therapy.

CONCLUSIONS

LHRH receptor expression was found to be very high in melanomas, RCCs and NHLs. Therefore targeted therapy with cytotoxic LHRH analogues may be a promising, novel therapy for advanced stages of these tumours. A first clinical trial with AN-152 was initiated recently in breast cancer patients.

[Her-2/neu analysis--new data?]

Her-2 status determination is an essential prerequisite before considering patient eligibility for treatment with trastuzumab. Currently the most common techniques to assess Her-2 status in routine practice are immunohistochemistry (IHC) and dual color FISH for receptor expression and gene amplification analysis, respectively. Despite both methods are well-established in breast cancer there are a variety of yet unsolved questions: 1. Do we really need IHC since interlab variation is still quite high (up to 30%)? 2. Are FISH and CISH equivalent techniques? 3. Are there any precautions to be taken if Her-2 is tested in non-breast cancer samples? 4. What is the value of Her-2 status in blood serum (ELISA)? 5. Do we get better response prediction if new Her2 antibodies, other techniques such as quantitative (q) RT-PCR or multiparameter assays according to downstream signalling pathways are applied? 6. Is Her-2 status still predictive when other therapeutic antibodies than trastuzumab (e. g. pertuzumab) or kinase inhibitors (e. g. lapatinib) are used? These questions will be discussed under the review of the recent literature and under own experiences obtained either by centralized Her-2 assessment in a variety of breast and non-breast cancer therapy studies and within international ring studies between reference labs from Australia (M. Bilous), Canada (W. Hanna), France (F. Penault-Llorcoa), Great Britain (M. Dowsett), Japan (R. Y. Osamura), and Netherlands (M. v. d. Vijver) in which we participated.

An animal model for anaplastic large cell lymphoma in the immunocompetent syngeneic C57Bl/6 mouse

We report on the analysis of a murine anaplastic lymphoid cell line TS1G6, established recently by interleukin (IL)-9 transfection. TS1G6 revealed a highly characteristic pattern of large anaplastic cells with mononuclear, binuclear, or multinuclear cells resembling Hodgkin (H) or Sternberg-Reed (SR) cells. This cell line is tumorigenous after injection of as few as 10(4) lymphoma cells into nude or immunocompetent C57Bl/6 mice and leads to death from progressive disease of all treated animals within a few weeks. The histological analysis of these tumors revealed a diffuse large cell malignant lymphoma that is morphologically almost identical to human anaplastic large cell lymphoma (ALCL). The lymphoma cells did not show overexpression of the anaplastic lymphoma kinase (ALK) gene, which is found in about 50% of the cases of human ALCL. Thus, this model may be an animal model for an important subset of human ALCL. The cytokine profile, which is of the T helper 2 type, showed strong parallels to the human lymphoma counterpart. Mice suffering from such lymphomas could not be cured with a regimen using high dose cyclophosphamide similar to many ALCL patients. Such an animal model for ALCL has not yet been recognized, but may provide the basis for investigating new antitumor immunotherapies in a fully immunocompetent host.