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Background and purpose: In times of high-precision radiotherapy, the accurate and precise definition of the primary tumour localisation and its microscopic spread is of enormous importance. In glioblastoma, the microscopic tumour extension is uncertain and therefore population-based margins for clinical target volume (CTV) definition are clinically used, which could either be too small leading to increased risk of loco-regional recurrences or too large thus enhancing the probability of normal tissue toxicity. Therefore, the aim of this project is to investigate an individualized definition of the CTV in preclinical glioblastoma models, based on specific biological tumour characteristics. Material and methods: The microscopic tumour extensions of two different orthotopic brain tumour models (U87MG_mCherry; G7_mCherry) were evaluated before and during fractionated radiotherapy and correlated with corresponding histological data. Representative tumour slices were analysed using Matrix-assisted Laser Desorption/Ionization (MALDI) and stained for putative cancer stem cell markers as well as invasion markers (Nestin, MMP14, Musashi 1, CD44). Results: The edges of the tumour are clearly shown by the MALDI segmentation via unsupervised clustering of mass spectra and are consistent with the histologically defined border in H&E staining in both models. MALDI component analysis supposed specific peaks as potential markers for normal brain tissue (e.g. 1339 m/z), whereas other peaks demarcated the tumours very well (e.g. 1562 m/z for U87MG_mCherry) irrespective of treatment. MMP14 staining revealed only a few positive cells mainly in the tumour border, which could reflect the invasive front in both models. Conclusion: The results of this study indicate that a step towards an individualized CTV definition based on biological tumour characteristics, especially using MALDI information, in glioblastoma models seems possible. Visualization of tumour volume and protein heterogeneity

Dendritic cells (DCs) play a key role in the orchestration of antitumor immunity. Activated DCs efficiently enhance antitumor effects mediated by natural killer cells and T lymphocytes. Conversely, tolerogenic DCs essentially contribute to an immunosuppressive tumor microenvironment. Thus, DCs can profoundly influence tumor progression and clinical outcome of tumor patients. To gain novel insights into the role of human DCs in pancreatic ductal adenocarcinoma (PDAC), we explored the frequency, spatial organization, and clinical significance of conventional DCs type 1 (cDC1s) and type 2 (cDC2s) and plasmacytoid DCs (pDCs) in primary PDAC tissues. A higher density of whole tumor area (WTA)- and tumor stroma (TS)-infiltrating cDC1s was significantly associated with better disease-free survival (DFS). In addition, an increased frequency of intraepithelial tumor-infiltrating cDC2s was linked to better DFS and overall survival (OS). Furthermore, an increased density of WTA- and TS-infiltrating pDCs tended to improve DFS. Moreover, a higher frequency of WTA- and TS-infiltrating cDC1s and pDCs emerged as an independent prognostic factor for better DFS and OS. These findings indicate that tumor-infiltrating DCs can significantly influence the clinical outcome of PDAC patients and may contribute to the design of novel treatment options that target PDAC-infiltrating DCs.

Contains fulltext : 225895.pdf (publisher's version ) (Open Access), Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours with a hereditary background in over one-third of patients. Mutations in succinate dehydrogenase (SDH) genes increase the risk for PPGLs and several other tumours. Mutations in subunit B (SDHB) in particular are a risk factor for metastatic disease, further highlighting the importance of identifying SDHx mutations for patient management. Genetic variants of unknown significance, where implications for the patient and family members are unclear, are a problem for interpretation. For such cases, reliable methods for evaluating protein functionality are required. Immunohistochemistry for SDHB (SDHB-IHC) is the method of choice but does not assess functionality at the enzymatic level. Liquid chromatography-mass spectrometry-based measurements of metabolite precursors and products of enzymatic reactions provide an alternative method. Here, we compare SDHB-IHC with metabolite profiling in 189 tumours from 187 PPGL patients. Besides evaluating succinate:fumarate ratios (SFRs), machine learning algorithms were developed to establish predictive models for interpreting metabolite data. Metabolite profiling showed higher diagnostic specificity compared to SDHB-IHC (99.2% versus 92.5%, p = 0.021), whereas sensitivity was comparable. Application of machine learning algorithms to metabolite profiles improved predictive ability over that of the SFR, in particular for hard-to-interpret cases of head and neck paragangliomas (AUC 0.9821 versus 0.9613, p = 0.044). Importantly, the combination of metabolite profiling with SDHB-IHC has complementary utility, as SDHB-IHC correctly classified all but one of the false negatives from metabolite profiling strategies, while metabolite profiling correctly classified all but one of the false negatives/positives from SDHB-IHC. From 186 tumours with confirmed status of SDHx variant pathogenicity, the combination of the two methods resulted in 185 correct predictions, hi

Phaeochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumours with a hereditary background in over one third of patients. Mutations in succinate dehydrogenase (SDH) genes increase the risk for PPGLs and several other tumours. Mutations in subunit B (SDHB) in particular are a risk factor for metastatic disease, further highlighting the importance of identifying SDH mutations for patient management. Genetic variants of unknown significance, where implications for the patient and family members are unclear, are a problem for interpretation. For such cases, reliable methods for evaluating protein functionality are required. Immunohistochemistry for SDHB (SDHB-IHC) is the method of choice, but does not assess functionality at the enzymatic level. Liquid chromatography mass spectrometry-based measurements of metabolite precursors and products of enzymatic reactions provides an alternative method. Here, we compare SDHB-IHC with metabolite profiling in 189 tumours from 187 PPGL patients. Besides evaluating succinate:fumarate ratios (SFR), machine learning algorithms were developed to establish predictive models for interpreting metabolite data. Metabolite profiling showed higher diagnostic specificity compared to SDHB-IHC (99.2% vs 92.5%, p=0.021), whereas sensitivity was comparable. Application of machine learning algorithms to metabolite profiles improved predictive ability over that of the SFR, in particular for hard-to-interpret cases of head and neck paragangliomas (AUC 0.9821 vs. 0.9613, p=0.044). Importantly, the combination of metabolite profiling with SDHB-IHC has complementary utility, as SDHB-IHC correctly classified all but one of the false-negatives from metabolite profiling strategies while metabolite profiling correctly classified all but one of the false-negatives/positives from SDHB-IHC. From 186 tumours with confirmed status of SDHx variant pathogenicity, the combination of the two methods resulted in 185 correct predictions, highlighting th

Contains fulltext : 206791.pdf (publisher's version ) (Open Access), Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors with a strong hereditary background and a large genetic heterogeneity. Identification of the underlying genetic cause is crucial for the management of patients and their families as it aids differentiation between hereditary and sporadic cases. To improve diagnostics and clinical management we tailored an enrichment based comprehensive multi-gene next generation sequencing panel applicable to both analyses of tumor tissue and blood samples. We applied this panel to tumor samples and compared its performance to our current routine diagnostic approach. Routine diagnostic sequencing of 11 PPGL susceptibility genes was applied to blood samples of 65 unselected PPGL patients at a single center in Dresden, Germany. Predisposing germline mutations were identified in 19 (29.2%) patients. Analyses of 28 PPGL tumor tissues using the dedicated PPGL panel revealed pathogenic or likely pathogenic variants in known PPGL susceptibility genes in 21 (75%) cases, including mutations in IDH2, ATRX and HRAS. These mutations suggest sporadic tumor development. Our results imply a diagnostic benefit from extended molecular tumor testing of PPGLs and consequent improvement of patient management. The approach is promising for determination of prognostic biomarkers that support therapeutic decision-making.

Contains fulltext : 207090.pdf (publisher's version ) (Closed access), Multimodal primary treatment of localised adenocarcinoma of the stomach, the oesophagus and the oesophagogastric junction (AEG) was reviewed by a multidisciplinary expert panel in a moderated consensus session. Here, we report the key points of the discussion and the resulting recommendations. The exact definition of the tumour location and extent by white light endoscopy in conjunction with computed tomography scans is the backbone for any treatment decision. Their value is limited with respect to the infiltration depth, lymph node involvement and peritoneal involvement. Additional endoscopic ultrasound was recommended mainly for tumours of the lower oesophagogastric junction (i.e. AEG type II and III according to Siewert) and in early cancers before endoscopic resection. Laparoscopy to diagnose peritoneal involvement was thought to be necessary before the start of neoadjuvant treatment in all gastric cancers and in AEG type II and III. In general, perioperative multimodal treatment was suggested for all locally advanced oesophageal tumours and for gastric cancers with a clinical stage above T1N0. There was consensus that the combination of fluorouracil, folinic acid, oxaliplatin and docetaxel is now a new standard chemotherapy (CTx) regimen for fit patients. In contrast, the optimal choice of perioperative CTx versus neoadjuvant radiochemotherapy (neoRCTx), especially for AEG, was identified as an open question. Expert treatment recommendations depend on the tumour location, biology, the risk of incomplete (R1) resection, response to treatment, local or systemic recurrence risks, the predicted perioperative morbidity and patients' comorbidities. In summary, any treatment decision requires an interdisciplinary discussion in a comprehensive multidisciplinary setting.

Background and purpose Oesophageal mobility relative to bony anatomy is a major source of geometrical uncertainty in proton radiotherapy of oesophageal carcinoma. To mitigate this uncertainty we investigated the use of implanted fiducial markers for direct target verification in terms of safety, visibility, and stability. Materials and methods A total of 19 helical gold markers were endoscopically implanted in ten patients. Their placement at the proximal and distal tumour borders was compared to tumour demarcations derived from [18F]Fluorodeoxyglucose positron emission tomography, their visibility quantified via the contrast-to-noise ratio on daily orthogonal X-ray imaging, and their mobility relative to bony anatomy analysed by means of retrospective triangulation. Results Marker implantation proceeded without complications, but the distal tumour border could not be reached in two patients. Marker locations corresponded reasonably well with metabolic tumour edges (mean: 5.4 mm more distally). Marker visibility was limited but mostly sufficient (mean contrast-to-noise ratio: 1.5), and sixteen markers (84%) remained in situ until the end of treatment. Overall, marker excursions from their planned position were larger than 5(10) mm in 59(17)% of all analysed fractions. On one occasion severe target displacement was only identified via markers and was corrected before treatment delivery. Conclusion Implanted helical gold fiducial markers are a safe and reliable method of providing target-centric positioning verification in proton beam therapy of oesophageal carcinoma.

Neoadjuvant radiochemotherapy (nRCT) can significantly influence the tumor immune architecture that plays a pivotal role in regulating tumor growth. Whereas various studies have investigated the effect of nRCT on tumor-infiltrating T cells, little is known about its impact on the frequency and activation status of human dendritic cells (DCs). Plasmacytoid DCs (pDCs) essentially contribute to the regulation of innate and adaptive immunity and may profoundly influence tumor progression. Recent studies have revealed that higher pDC numbers are associated with poor prognosis in cancer patients. 6-sulfo LacNAc-expressing monocytes (slanMo) represent a particular proinflammatory subset of human non-classical blood monocytes that can differentiate into DCs. Recently, we have reported that activated slanMo produce various proinflammatory cytokines and efficiently stimulate natural killer cells and T lymphocytes. slanMo were also shown to accumulate in clear cell renal cell carcinoma and in metastatic lymph nodes from cancer patients. In the present study, we investigated the influence of nRCT on frequency and phenotype of rectal cancer-infiltrating pDCs and slanMo. When evaluating rectal cancer tissues obtained from patients after nRCT, a significantly higher frequency of pDCs in comparison to non-matched pre-nRCT tissue samples was found. In contrast, the density of slanMo was not significantly altered by nRCT. These findings were confirmed when analyzing matched pre-nRCT and post-nRCT rectal cancer specimens. Further studies revealed that nRCT significantly increases the percentage of mature CD83+ pDCs in rectal cancer tissues. Moreover, the proportion of pDCs locally expressing interferon-alpha, which plays a major role in antitumor immunity, was significantly higher in post-nRCT. In addition, nRCT markedly enhanced the percentage of inducible nitric oxide synthase- or tumor necrosis factor alpha-producing slanMo in rectal cancer tissues. These novel findings indicate th