[Application of FISH in the diagnosis of lung cancer]. / Anwendungen der FISH in der Diagnostik von Lungenkarzinomen.

Rapid advancements in the area of lung cancer therapy were determined by the discovery of molecular markers and the possibility of their therapeutic exploitation. Today's lung cancer diagnosis places high demands on pathologists. In the majority of cases, small tissue samples must suffice for diagnosis and testing of all relevant biomarkers. The minimum panel required for advanced non-small-cell lung carcinoma (NSCLC) with nonsquamous histology includes testing of EGFR, BRAF, ALK, ROS1, and PD-L1-expression. So far, only PD-L1-IHC (immunohistochemistry, IHC) is required for squamous cell carcinoma. If possible, newer biomarkers such as RET, MET, HER2, NTRK, and KRAS should be integrated in test panels. Fluorescence in situ hybridization (FISH) is a well-established molecular method for the detection of chromosomal aberrations, such as ALK-, ROS1-, and RET- translocations and amplifications, such as Her2/neu or MET. The relevance of MET-FISH for the detection of amplifications in the first-line setting is controversial, but of high importance in the recurrent setting. All equivocal or discrepant results should be validated using orthogonal methods. IHC is a suitable, thoroughly validated method for ALK and ROS1 aberration detection with the advantage of quick and cost-efficient test results and tissue conservation. All other translocations, or discrepancy between IHC and FISH, require a sequencing-based confirmation procedure. The low frequency of NTRK fusions, and high sensitivity of NTRK-IHC, suggest using IHC as a prescreening tool with subsequent sequencing-based analysis for IHC positive cases.

First reported case of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma: a case report.

BACKGROUND: Collision tumors are rare cases with two different tumor entities growing synchronously. While adenocarcinoma of the pancreas is the most common pancreatic tumor with an incidence of 10 per 100.000, retroperitoneal liposarcoma remains very rare. This is the first report of a collision tumor between these two tumor entities. CASE PRESENTATION: Demographic details: The tumor was diagnosed in a 64 male Caucasian patient. Besides atrial fibrillation, arterial hypertension and a hypothyroidism there is no relevant medical history especially no history of cancer. Clinical details: During a routine check-up an unclassified tumor of the pancreatic tail was diagnosed. The lab showed no pathologies. Tumor markers were negative for carbohydrate antigen 19-9 and 72-4 (CA 19-9, CA 72-4) and carcinoembryonic antigen (CEA). Alpha-fetoprotein (AFP) and neuron specific enolase (NSE) were both elevated (AFP 97kU/l, (< 5,8kU/l) and NSE 30,0 µg/l (16,4 µg/l)). A computed tomography-guided core needle biopsy was performed which revealed a low-grade liposarcoma (G1). A CT scan showed no metastases. A surgical resection was recommended by the interdisciplinary tumor board. INTERVENTIONS: A systematic left sided retroperitoneal compartment resection including en-bloc-left sided pancreatectomy, splenectomy, nephrectomy, hemicolectomy, adrenalectomy, partial gastrectomy and partial resection of the diaphragm was performed. Pathology revealed a collision tumor consisting of pancreatic adenocarcinoma that was classified pT3, pN2 (11/33 ece+) L1 V0 Pn0, R0; G2 [UICC Stage III] and a liposarcoma pT2, pN0 (0/33) L0 V0 Pn0, G1 [UICC Stage Ib]. The postoperative tumor board recommended an adjuvant chemotherapy with gemcitabine and capecitabine for the locally advanced pancreatic adenocarcinoma. OUTCOME: At the latest follow-up (1 year after surgery) the patient was in good clinical condition and without evidence of tumor recurrence. CONCLUSION: Collision tumors are rare and difficult to diagnose. This is the first description of a collision tumor composed of pancreatic adenocarcinoma and retroperitoneal liposarcoma. The reported case demonstrates that inconsistent diagnostic results (e.g. imaging and pathology) should raise suspicion concerning the diagnosis. Awareness of these rare cases might protect us from underdiagnosing patients and therefore leading to better patient care. There is evolving evidence that will lead to more personalized treatment options for somatic BRCA mutated pancreatic cancer.

Molecular In-Depth Characterization of Chondrosarcoma for Current and Future Targeted Therapies.

Chondrosarcoma (CHS) are heterogenous, but as a whole, represent the second most common primary malignant bone tumor entity. Although knowledge on tumor biology has grown exponentially during the past few decades, surgical resection remains the gold standard for the treatment of these tumors, while radiation and differentiated chemotherapy do not result in sufficient cancer control. An in-depth molecular characterization of CHS reveals significant differences compared to tumors of epithelial origin. Genetically, CHS are heterogenous, but there is no characteristic mutation defining CHS, and yet, IDH1 and IDH2 mutations are frequent. Hypovascularization, extracellular matrix composition of collagen, proteoglycans, and hyaluronan create a mechanical barrier for tumor suppressive immune cells. Comparatively low proliferation rates, MDR-1 expression and an acidic tumor microenvironment further limit therapeutic options in CHS. Future advances in CHS therapy depend on the further characterization of CHS, especially the tumor immune microenvironment, for improved and better targeted therapies.

FGFR2-amplified tumor clones are markedly heterogeneously distributed in carcinomas of the upper gastrointestinal tract.

BACKGROUND: FGFR2 is a therapy-relevant target in tumors of the upper gastrointestinal tract (GIT), and clinical trials are currently underway to test the efficacy of FGFR2 inhibitors. Tumor heterogeneity is one of the relevant causes of treatment failure. Almost nothing is known about the heterogeneous distribution of FGFR2-amplified clones in adenocarcinomas of the upper GIT. PATIENTS AND METHODS: To assess FGFR2 gene copy number alteration and intratumoral heterogeneity of upper GIT adenocarcinomas, we analyzed 893 patient-derived formalin-fixed paraffin-embedded tumor specimens, including primary operated and neoadjuvant-treated tumors (462 gastric carcinomas and 429 esophageal adenocarcinomas) as well as complementary lymph node and distant metastasis by fluorescence in situ hybridization. RESULTS: Twenty-six gastric tumors (5.6%) and 21 esophageal adenocarcinomas (4.9%) showed FGFR2 amplification. Overall, 93% of gastric carcinomas and 83% of esophageal carcinomas showed heterogeneous amplification. FGFR2 amplification was found in different histological growth patterns, including intestinal and diffuse type according to the Lauren classification. In the primary gastric carcinoma group, FGFR2 amplification was associated with poor prognosis (p = 0.005). CONCLUSION: Homogeneous FGFR2 amplification in tumors of the upper GIT is the exception. This has highly relevant implications in the nature of FGFR2 diagnostics (sufficient tumor cell number, determination of amplification at metastasis versus primary tumor, etc.) and on the response probability of appropriate inhibitors. It is relevant that the often poorly treatable and aggressive subtype of diffuse carcinomas (poorly cohesive carcinomas) also shows FGFR2 amplification and that an individualized therapy option with FGFR2 inhibitors could be an option in this group.

Resistance to MET inhibition in MET-dependent NSCLC and therapeutic activity after switching from type I to type II MET inhibitors.

OBJECTIVES: Resistance to MET inhibition occurs inevitably in MET-dependent non-small cell lung cancer and the underlying mechanisms are insufficiently understood. We describe resistance mechanisms in patients with MET exon 14 skipping mutation (METΔex14), MET amplification, and MET fusion and report treatment outcomes after switching therapy from type I to type II MET inhibitors. MATERIALS AND METHODS: Pre- and post-treatment biopsies were analysed by NGS (next generation sequencing), digital droplet PCR (polymerase chain reaction), and FISH (fluorescense in situ hybridization). A patient-derived xenograft model was generated in one case. RESULTS: Of 26 patients with MET tyrosine kinase inhibitor treatment, eight had paired pre- and post-treatment biopsies (Three with MET amplification, three with METΔex14, two with MET fusions (KIF5B-MET and PRKAR2B-MET).) In six patients, mechanisms of resistance were detected, whereas in two cases, the cause of resistance remained unclear. We found off-target resistance mechanisms in four cases with KRAS mutations and HER2 amplifications appearing. Two patients exhibited second-site MET mutations (p.D1246N and p. Y1248H). Three patients received type I and type II MET tyrosine kinase inhibitors sequentially. In two cases, further progressive disease was seen hereafter. The patient with KIF5B-MET fusion received three different MET inhibitors and showed long-lasting stable disease and a repeated response after switching therapy, respectively. CONCLUSION: Resistance to MET inhibition is heterogeneous with on- and off-target mechanisms occurring regardless of the initial MET aberration. Switching therapy between different types of kinase inhibitors can lead to repeated responses in cases with second-site mutations. Controlled clinical trials in this setting with larger patient numbers are needed, as evidence to date is limited to preclinical data and case series.

International Tumor Budding Consensus Conference criteria determine the prognosis of oesophageal adenocarcinoma with poor response to neoadjuvant treatment.

BACKGROUND: Neoadjuvant therapy regimens followed by surgery represent the current standard treatment of locally advanced oesophageal adenocarcinomas. Tumour regression determines prognosis, but more than half of patients do have more than 10% residual tumour after neoadjuvant therapy. In these cases, classical histopathological parameters for the determination of prognosis are of limited value. Therefore, we investigated whether tumour budding could be an additional prognostic factor for tumours with poor response to neoadjuvant therapy. METHODS: Tumour budding was assessed according to a standardized consensus quantification method as proposed by the International Tumor Budding Consensus Conference (ITBCC) in H&E-stained whole tissue slides of 278 formalin-fixed paraffin-embedded (FFPE) resected oesophageal adenocarcinomas with a poor response (> 10% vital residual tumour) to neoadjuvant therapy. RESULTS: We could demonstrate a strong positive correlation (p < 0.05) between the budding group, ypN stage and UICC tumour stage. Further, high numbers of tumour buds were a significant and independent negative prognostic marker for OS in all studied patients (HR = 1.039 (95% CI 1.012-1.066), p = 0.004). ITBCC budding groups were an independent prognostic parameter. CONCLUSIONS: Tumour budding assessed in accordance with the ITBCC criteria may aid in the prognostic stratification of locally advanced oesophageal adenocarcinoma with poor response to neoadjuvant treatment.

Cardiac metastasis causes paradoxical malignant embolism.

BACKGROUND: Embolic events play an important role in clinical everyday practice. Malignant arterial embolism is a rare nevertheless often fatal entity for cardiac, cerebral or systemic ischemia, requiring immediate diagnosis and treatment. CASE: This is a case report of a 65 years-old female, suffering from pulmonal adenocarcinoma, who was hospitalized due to neurological deficits caused by an acute ischemic stroke, followed by anterior myocardial infarction within 3 days. Diagnostic work-up revealed metastasis of the pulmonal adenocarcinoma in the right atrium and a patent foramen ovale. Histopathological examination of the coronary embolus verified paradoxical arterial embolism of the pulmonal adenocarcinoma into a coronary vessel and consequently cerebral arteries. CONCLUSION: The present case underlines the need for (i), consideration of malignant embolism, (ii) histopathological examination of the embolus to determine its etiology, and (iii) interdisciplinary discussion of individual therapeutic and prevention strategies in cancer patients with cerebral, cardiac or systemic embolic events.

Mismatch Repair Deficiency and Somatic Mutations in Human Sinonasal Tumors.

Due to limitations in local therapy approaches for sinonasal tumors, improvement in systemic therapies plays a pivotal role for prolongation of the patient's survival. The aim of this study was to examine potential biomarkers, including deficiency in mismatch repair proteins (dMMR)/microsatellite instability (MSI-H) in sinonasal cancers and their precancerous lesions. A comprehensive analysis of 10 sinonasal cancer cell lines by whole exome sequencing, screening 174 sinonasal tumors by immunohistochemistry (IHC) for mismatch repair deficiency and next generation sequencing (NGS) of 136 tumor samples revealed a dMMR/MSI-H sinonasal squamous cell carcinoma (SNSCC) cell line based on a somatic missense mutation in MLH1 and an overall frequency of dMMR/MSI-H SNSCC of 3.2% (4/125). Targetable EGFR mutations were found in 89.3% (25/28) of inverted sinonasal papilloma (ISP) and in 60% (6/10) of ISP-associated carcinomas. While PIK3CA and EGFR mutations were not mutually exclusive, KRAS mutated tumors were an EGFR-wildtype. The effect of potential driver mutations in FGFR2, FGFR3, BRAF, HRAS, MAP2K1, PTEN, NOTCH1 and CARD11 need further investigation. Our results suggest that biomarker testing, including MMR-IHC and NGS panel analysis, should be integrated into the diagnostics of clinically aggressive ISPs and SNSCC to assess prognosis and facilitate therapeutic decisions.

Tumor budding assessed according to the criteria of the International Tumor Budding Consensus Conference determines prognosis in resected esophageal adenocarcinoma.

Only few studies examined the prognostic effect of tumor budding in esophageal adenocarcinomas so far. However, different quantification approaches were used, so results cannot be directly compared. Recently, the International Tumor Budding Consensus Conference (ITBCC) published consensus criteria for the evaluation of tumor budding in colorectal cancer, which we applied in our study. Hematoxylin and eosin (H&E) and cytokeratin (AE1/AE3) stained whole tissue slides of 104 resected esophageal adenocarcinomas were evaluated. The mean count of tumor buds was analyzed in one high power field according to the ITBCC criteria and assigned to budding groups Bd1-3. Tumor budding was significantly associated with a worse overall survival. Regardless of the quantification approach, an increased number of tumor buds was significantly associated with reduced overall survival (OS) (H&E: HR = 1.05 (95% CI 1.029-1.073), p < 0.001; cytokeratin: HR = 1.073 (95% CI 1.045-1.101), p < 0.001). In multivariable analysis tumor budding according to ITBCC criteria on H&E stained slides was an independent prognostic factor. Tumor budding, according to ITBCC criteria, is an independent prognostic factor in resected esophageal adenocarcinoma. Prospective studies using ITBCC criteria are useful in the near future to validate our results.

Interdisciplinary assessment and management of a patient with a fibrous gingival enlargement of unknown origin: A case report.

A gingival enlargement of unclear cause could only be diagnosed after interdisciplinary cooperation as plasma cell gingivitis of unknown origin. Interdisciplinary approaches remain crucial when diagnosing rare gum diseases.

Intestinal manipulation affects mucosal antimicrobial defense in a mouse model of postoperative ileus.

AIM: To explore the effects of abdominal surgery and interleukin-1 signaling on antimicrobial defense in a model of postoperative ileus. METHODS: C57BL/6 and Interleukin-1 receptor type I (IL-1R1) deficient mice underwent intestinal manipulation to induce POI. Expression of mucosal IL-1α, IL-1ß and IL-1R1 and several antimicrobial peptides and enzymes were measured by quantitative PCR or ELISA, western blotting or immunohistochemistry. Bacterial overgrowth was determined by fluorescent in-situ hybridization and counting of jejunal luminal bacteria. Translocation of aerobic and anaerobic bacteria into the intestinal wall, mesenteric lymph nodes, liver and spleen was determined by counting bacterial colonies on agar plates 48h after plating of tissue homogenates. Antimicrobial activity against E. coli and B. vulgatus was analyzed in total and cationic fractions of small bowel mucosal tissue homogenates by a flow cytometry-based bacterial depolarization assay. RESULTS: Jejunal bacterial overgrowth was detected 24h after surgery. At the same time point, but not in the early phase 3h after surgery, bacterial translocation into the liver and mesenteric lymph nodes was observed. Increased antimicrobial activity against E. coli was induced within early phase of POI. Basal antimicrobial peptide and enzyme gene expression was higher in the ileal compared to the jejunal mucosa. The expression of lysozyme 1, cryptdin 1, cryptdin 4 and mucin 2 were reduced 24h after surgery in the ileal mucosa and mucin 2 was also reduced in the jejunum. Postoperative IL-1α and IL-1ß were increased in the postoperative mucosa. Deficiency of IL-1R1 affected the expression of antimicrobial peptides during homeostasis and POI. CONCLUSION: Small bowel antimicrobial capacity is disturbed during POI which is accompanied by bacterial overgrowth and translocation. IL-1R1 is partially involved in the gene expression of mucosal antimicrobial peptides. Altered small bowel antimicrobial activity may contribute also to POI development and manifestation in patients undergoing abdominal surgery.