Martina Friess

PI3K/mTOR Signaling in Mesothelioma Patients Treated with Induction Chemotherapy Followed by Extrapleural Pneumonectomy

Introduction: The prognostic significance of activity biomarkers within the phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway was assessed in two independent cohorts of malignant pleural mesothelioma (MPM) patients uniformly treated with a multimodal approach. We specifically assessed expression signatures in a unique set of pre- and postchemotherapy tumor samples. Methods: Biomarker expression was assessed in samples of two independent cohorts of 107 (cohort 1) and 46 (cohort 2) MPM cases uniformly treated with platinum-based induction chemotherapy followed by extrapleural pneumonectomy from two different institutions, assembled on tissue microarrays. Expression levels of phosphatase and tensin homologue (PTEN), phospho-mTOR, and p-S6 in addition to marker of proliferation (Ki-67) and apoptosis (cleaved caspase-3) were evaluated by immunohistochemistry and correlated with overall survival (OAS) and progression-free survival (PFS). To assess PTEN genomic status, fluorescence in situ hybridization was performed. Results: Survival analysis showed that high p-S6 and Ki-67 expression in samples of treatment naïve patients of cohort 1 was associated with shorter PFS (p = 0.02 and p = 0.04, respectively). High Ki-67 expression after chemotherapy remained associated with shorter PFS (p = 0.03) and OAS (p = 0.02). Paired comparison of marker expression in samples before and after induction chemotherapy of cohort 1 revealed that decreased cytoplasmic PTEN and increased phospho-mTOR expression was associated with a worse OAS (p = 0.04 and p = 0.03, respectively). Conclusions: These novel data reveal a prognostic significance of expression changes of PI3K/mTOR pathway components during induction chemotherapy if confirmed in other patient cohorts and support the growing evidence to target the PI3K/mTOR pathway in the treatment of MPM.

EPIZOOTIOLOGIC INVESTIGATIONS OF SELECTED ABORTIVE AGENTS IN FREE-RANGING ALPINE IBEX (CAPRA IBEX IBEX ) IN SWITZERLAND

In the early 2000s, several colonies of Alpine ibex (Capra ibex ibex) in Switzerland ceased growing or began to decrease. Reproductive problems due to infections with abortive agents might have negatively affected recruitment. We assessed the presence of selected agents of abortion in Alpine ibex by serologic, molecular, and culture techniques and evaluated whether infection with these agents might have affected population densities. Blood and fecal samples were collected from 651 ibex in 14 colonies throughout the Swiss Alps between 2006 and 2008. All samples were negative for Salmonella spp., Neospora caninum, and Bovine Herpesvirus-1. Antibodies to Coxiella burnetii, Leptospira spp., Chlamydophila abortus, Toxoplasma gondii, and Bovine Viral Diarrhea virus were detected in at least one ibex. Positive serologic results for Brucella spp. likely were false. Overall, 73 samples (11.2%) were antibody-positive for at least one abortive agent. Prevalence was highest for Leptospira spp. (7.9%, 95% CI=5.0–11.7). The low prevalences and the absence of significant differences between colonies with opposite population trends suggest these pathogens do not play a significant role in the population dynamics of Swiss ibex. Alpine ibex do not seem to be a reservoir for these abortive agents or an important source of infection for domestic livestock in Switzerland. Finally, although interactions on summer pastures occur frequently, spillover from infected livestock to free-ranging ibex apparently is uncommon.

A New Prognostic Score Supporting Treatment Allocation for Multimodality Therapy for Malignant Pleural Mesothelioma: A Review of 12 Years' Experience

Introduction: Treatment of malignant pleural mesothelioma (MPM) remains a clinical challenge. The aim of this study was to identify selection factors for allocation of MPM patients to multimodal therapy based on survival data from 12 years of experience. Methods: Eligible patients had MPM of all histological subtypes with clinical stage T1–3 N0–2 M0. Induction chemotherapy consisted of cisplatin/gemcitabine (cis/gem) or cisplatin/pemetrexed (cis/pem), followed by extrapleural pneumonectomy (EPP). Multivariate analysis was performed to assess independent prognosticators for overall survival (OS). A Multimodality Prognostic Score was developed based on clinical variables available before surgery. Results: From May 1999 to August 2011, 186 MPM patients were intended to be treated with induction chemotherapy followed by EPP. Hematologic toxicity was significantly less frequent after cis/pem compared to cis/gem, but there was no difference in response or OS between the regimens. One hundred and twenty-eight patients underwent EPP with a 30-day mortality of 4.7%. Fifty-two percent of the patients received adjuvant radiotherapy. The median OS of patients undergoing EPP was significantly longer with 22 months (95% confidence interval: 20–24) when compared to 11 months (9–12) for patients treated without EPP. A prognostic score was defined considering tumor volume, histology, C-reactive protein level, and response to chemotherapy that identified patient groups not benefitting from multimodality treatment which was confirmed in an independent cohort. Conclusion: Patients receiving induction chemotherapy followed by EPP for MPM of all histological subtypes and irrespective of nodal status showed a median survival of 22 months. A prognostic score is proposed to help patient allocation for surgery after validation in an independent cohort.

Extrapleural Pneumonectomy After Induction Chemotherapy: Perioperative Outcome in 251 Mesothelioma Patients From Three High-Volume Institutions

BACKGROUND Several publications have suggested that induction chemotherapy followed by extrapleural pneumonectomy (EPP) for patients with malignant pleural mesothelioma (MPM) patients is associated with exceedingly high morbidity and mortality, and the role of EPP is controversially debated. The present retrospective study analyzed the perioperative outcome in 251 consecutively treated patients at three high-volume mesothelioma centers. METHODS 251 MPM patients completed EPP after platinum-based induction chemotherapy at three institutions for thoracic surgery over more than 10 years. The rates of 30-day and 90-day mortality and of major morbidities (pulmonary embolism, postoperative bleeding, acute respiratory distress syndrome, empyema, bronchopleural fistula (BPF), chylothorax, patch failure) were recorded. Perioperative outcome was correlated to risk factors such as smoking history (pack years), age at operation, body mass index, spirometry results, C-reactive protein, American Society of Anesthesiologists classification, chemotherapy regimen used, blood loss during operation, duration of operation, and characteristics of the tumor (laterality, histologic subtype, pT and pN stage) to find factors predicting 30-day and 90-day mortality or major morbidity. RESULTS The overall 30-day mortality was 5%. Within 90 days after operation, 8% of the patients died. The rates of 30-day and 90-day mortality were significantly higher in patients with high preoperative C-reactive protein values (p=0.001 and p<0.0005). The spirometry values forced expiratory volume in 1 second and forced vital capacity exhaled (FVCex) were both associated with 30-day and 90-day mortality (p=0.001 and p<0.0005; and p=0.002 and p<0.0005). Major morbidity occurred in 30% of the patients, significantly more often after right-sided EPP (p=0.01) and after longer operations (p<0.0005). Empyema (p<0.0005) and acute respiratory distress syndrome (p=0.02) were associated with longer duration of operation. CONCLUSIONS EPP after induction chemotherapy is a demanding procedure but can be performed with acceptable morbidity and mortality if patients are well selected and treated at dedicated high-volume MPM centers.

Low Merlin expression and high Survivin labeling index are indicators for poor prognosis in patients with malignant pleural mesothelioma

Alterations of the tumor suppressor Neurofibromatosis type II (NF2) have been reported in about 40% of Malignant pleural mesothelioma (MPM) patients. NF2 (Merlin) deficiency leads to alterations of the Hippo pathway; resulting in activation of the oncogenic Yes Associated Protein‐1 (YAP1). Our aim was to investigate the association between these alterations and clinical outcomes.

Relapse pattern and second-line treatment following multimodality treatment for malignant pleural mesothelioma.

OBJECTIVES To analyse the relapse pattern and influence of second-line treatment after recurrence of malignant pleural mesothelioma (MPM) in patients who had previously undergone multimodality treatment. METHODS Between September 1999 and December 2013, 136 patients underwent macroscopic complete resection (MCR) by extrapleural pneumonectomy after induction chemotherapy for MPM. We analysed 106 patients who presented with recurrent disease until October 2014. Data were retrieved from our mesothelioma database, with additional information regarding precise localization gathered by reviewing the imaging and medical records. RESULTS The overall recurrence rate was 78% (106/136 patients). The median freedom from recurrence was 9 months after surgery [95% confidence interval (95% CI) 7-10]. Local recurrence only was observed in 33 patients (31%), distant metastases only in 27 patients (26%) and simultaneous distant and local recurrence in 46 patients (43%). Local recurrence was observed significantly less frequently in patients having received adjuvant radiotherapy (19 vs 47%, P = 0.003), but there was no significant impact on overall survival (OS) [radiation: 22 months (95% CI 19-24); no-radiation: 23 months (95% CI 18-27), P = 0.6]. The median OS was 22 months (95% CI 21-24), median post-recurrence survival (PRS) was 7 months (95% CI 5-9) and patients with local recurrence only survived significantly longer (12 months, 95% CI 8-16) compared with patients with distant recurrence only (5 months, 95% CI 2-8) or distant plus local relapse (6 months, 95% CI 3-9; P = 0.04). A total of 78 patients received a second-line therapy after tumour recurrence: chemotherapy (n = 48), local radiotherapy (n = 9), surgery (n = 10) or a combination thereof (n = 11). Patients undergoing second-line treatment survived significantly longer compared with patients not receiving therapy (P < 0.0005). The median PRS after surgery was significantly longer than that of patients receiving chemo-, radio- or chemo-radiotherapy (P = 0.04). CONCLUSIONS Local recurrence of MPM remains the most frequent type of relapse even after multimodality treatment including MCR. In the present cohort, active treatment seems beneficial to the patient since surgical excision of local tumour relapse has good long-term outcome in selected patients. Thus, second-line treatment may prolong PRS; however, these results need to be confirmed in a prospective manner.

Propensity matched comparison of extrapleural pneumonectomy and pleurectomy/decortication for mesothelioma patients

OBJECTIVES The objective of this retrospective study was to assess perioperative outcomes, overall survival and freedom from recurrence after induction chemotherapy followed by extrapleural pneumonectomy (EPP) or pleurectomy/decortication (P/D) in patients with mesothelioma in a propensity score matched analysis. METHODS Between September 1999 and August 2015, 167 patients received multimodality treatment (platinum-based chemotherapy followed by EPP [ n =  141] or P/D [ n =  26]). We performed 2:1 propensity score matching for gender, laterality, epithelioid histological subtype and International Mesothelioma Interest Group (iMig) stage (52 EPP and 26 P/D). RESULTS Postoperative major morbidity (48% vs 58%, P =  0.5) was similar in both groups; however, the complication profile and severity were different and favoured P/D; the 90-day mortality (8% vs 0%, P =  0.3) rate was lower in P/D although not statistically significant. Prolonged air leak (≥10 days) occurred in 15 patients (58%) undergoing P/D. The intensive care unit stay was significantly longer after EPP ( P =  0.001). Freedom from recurrence was similar for both groups (EPP: median 15 months, 95% confidence interval [CI]: 10-21; P/D: 13 months, 95% CI: 11-17) ( P =  0.2). Overall survival was significantly longer for patients undergoing P/D (median 32 months, 95% CI: 29-35) compared to EPP (23 months, 95% CI: 21-25) ( P =  0.031), but in the P/D group many cases were censored (73%) and the follow-up time was relatively short. CONCLUSIONS P/D and EPP seem to have similar rates of major morbidity, although the profile of complications is different and more severe after EPP. Freedom from recurrence is comparable in both groups whereas improved overall survival needs to be confirmed in a large patient group with longer follow-up.

Expression of the Stem Cell Factor Nestin in Malignant Pleural Mesothelioma Is Associated with Poor Prognosis

Background The epithelioid and sarcomatoid histologic variants of malignant pleural mesothelioma (MPM) can be considered as E- and M-parts of the epithelial-mesenchymal transition (EMT) axis; the biphasic being an intermediate. EMT is associated with an increase of stem cell (SC) traits. We correlated the neural crest SC marker nestin and the EMT marker periostin with histology, type of neo-adjuvant chemotherapy (CT) and overall survival (OS) of MPM patients. Patients and Methods Tumor tissues of a historic cohort 1 (320 patients) and an intended induction chemotherapy followed by extrapleural pneumonectomy (EPP) cohort 2 (145 patients) were immunohistochemically H-scored (intensity of immunoreactivity multiplied by frequency of stained cells). Paired chemo-naïve biopsies and -treated surgical specimens were available for 105/145 patients. CT included platinum/gemcitabine (Pla/Gem) or platinum/pemetrexed (Pla/Pem). Results Expression of any cytosolic nestin progressively increased from epithelioid to biphasic to sarcomatoid MPM in cohort 1, whereas the diagnostic markers calretinin and podoplanin decreased. In cohort 2, Pla/Pem CT increased the expression level of nestin in comparison to Pla/Gem, whereas the opposite was found for periostin. In Pla/Pem treated patients, nestin was higher in biphasic MPM compared to epithelioid. In addition to non-epithelioid histology, any expression of nestin in chemo-naïve biopsies (median overall survival: 22 vs. 17 months) and chemo-treated surgical specimens (18 vs. 12 months) as well as high periostin in biopsies (23 vs. 15 months) were associated with poor prognosis. In the multivariate survival analysis, any nestin expression in chemo-naïve biopsies proved to be an independent prognosticator against histology. In both pre- and post-CT situations, the combination of nestin or periostin expression with non-epithelioid histology was particularly/ dismal (all p-values <0.05). Conclusions The SC marker nestin and the EMT marker periostin allow for further prognostic stratification among histologic variants of MPM. Their expression level is influenced by neo-adjuvant chemotherapy.

Two Different Macaviruses, ovine herpesvirus-2 and caprine herpesvirus-2, behave differently in water buffaloes than in cattle or in their respective reservoir species.

The ongoing global spread of “exotic” farm animals, such as water buffaloes, which carry their native sets of viruses, may bear unknown risks for the animals, into whose ecological niches the former are introduced and vice versa. Here, we report on the occurrence of malignant catarrhal fever (MCF) on Swiss farms, where “exotic” water buffaloes were kept together with “native” animals, i.e. cattle, sheep, and goats. In the first farm with 56 water buffaloes, eight cases of MCF due to ovine herpesvirus-2 (OvHV-2) were noted, whereas additional ten water buffaloes were subclinically infected with either OvHV-2 or caprine herpesvirus-2 (CpHV-2). On the second farm, 13 water buffaloes were infected with CpHV-2 and two of those succumbed to MCF. In neither farm, any of the two viruses were detected in cattle, but the Macaviruses were present at high prevalence among their original host species, sheep and goats, respectively. On the third farm, sheep were kept well separated from water buffaloes and OvHV-2 was not transmitted to the buffaloes, despite of high prevalence of the virus among the sheep. Macavirus DNA was frequently detected in the nasal secretions of virus-positive animals and in one instance OvHV-2 was transmitted vertically to an unborn water buffalo calf. Thus, water buffaloes seem to be more susceptible than cattle to infection with either Macavirus; however, MCF did not develop as frequently. Therefore, water buffaloes seem to represent an interesting intermediate-type host for Macaviruses. Consequently, water buffaloes in their native, tropic environments may be vulnerable and endangered to viruses that originate from seemingly healthy, imported sheep and goats.

Influence of inter-observer delineation variability on radiomics stability in different tumor sites

Abstract Background: Radiomics is a promising methodology for quantitative analysis and description of radiological images using advanced mathematics and statistics. Tumor delineation, which is still often done manually, is an essential step in radiomics, however, inter-observer variability is a well-known uncertainty in radiation oncology. This study investigated the impact of inter-observer variability (IOV) in manual tumor delineation on the reliability of radiomic features (RF). Methods: Three different tumor types (head and neck squamous cell carcinoma (HNSCC), malignant pleural mesothelioma (MPM) and non-small cell lung cancer (NSCLC)) were included. For each site, eleven individual tumors were contoured on CT scans by three experienced radiation oncologists. Dice coefficients (DC) were calculated for quantification of delineation variability. RF were calculated with an in-house developed software implementation, which comprises 1404 features: shape (n = 18), histogram (n = 17), texture (n = 137) and wavelet (n = 1232). The IOV of RF was studied using the intraclass correlation coefficient (ICC). An ICC >0.8 indicates a good reproducibility. For the stable RF, an average linkage hierarchical clustering was performed to identify classes of uncorrelated features. Results: Median DC was high for NSCLC (0.86, range 0.57–0.90) and HNSCC (0.72, 0.21–0.89), whereas it was low for MPM (0.26, 0–0.9) indicating substantial IOV. Stability rate of RF correlated with DC and depended on tumor site, showing a high stability in NSCLC (90% of total parameters), acceptable stability in HNSCC (59% of total parameters) and low stability in MPM (36% of total parameters). Shape features showed the weakest stability across all tumor types. Hierarchical clustering revealed 14 groups of correlated and stable features for NSCLC and 6 groups for both HNSCC and MPM. Conclusion: Inter-observer delineation variability has a relevant influence on radiomics analysis and is strongly influenced by tumor type. This leads to a reduced number of suitable imaging features.