[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.

[Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]

BACKGROUND

Autopsies are a valuable tool for understanding disease, including COVID-19.

MATERIALS AND METHODS

The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs.

RESULTS

The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy.

CONCLUSIONS

Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.

Rationale and design of the CRAFT (Continuous ReAssessment with Flexible ExTension in Rare Malignancies) multicenter phase II trial

BACKGROUND

Approvals of cancer therapeutics are primarily disease entity specific. Current molecular diagnostic approaches frequently identify actionable alterations in rare cancers or rare subtypes of common cancers for which the corresponding treatments are not approved and unavailable within clinical trials due to entity-related eligibility criteria. Access may be negotiated with health insurances. However, approval rates vary, and critical information required for a scientific evaluation of treatment-associated risks and benefits is not systematically collected. Thus clinical trials with optimized patient selection and comprehensive molecular characterization are essential for translating experimental treatments into standard care.

PATIENTS AND METHODS

Continuous ReAssessment with Flexible ExTension in Rare Malignancies (CRAFT) is an open-label phase II trial for adults with pretreated, locally advanced, or metastatic solid tumors. Based on the evaluation by a molecular tumor board, patients are assigned to combinations of six molecularly targeted agents and a programmed death-ligand 1 (PD-L1) antagonist within seven study arms focusing on (i) BRAF V600 mutations; (ii) ERBB2 amplification and/or overexpression, activating ERBB2 mutations; (iii) ALK rearrangements, activating ALK mutations; (iv and v) activating PIK3CA and AKT mutations, other aberrations predicting increased PI3K-AKT pathway activity; (vi) aberrations predicting increased RAF-MEK-ERK pathway activity; (vii) high tumor mutational burden and other alterations predicting sensitivity to PD-L1 inhibition. The primary endpoint is the disease control rate (DCR) at week 16; secondary and exploratory endpoints include the progression-free survival ratio, overall survival, and patient-reported outcomes. Using Simon's optimal two-stage design, 14 patients are accrued for each study arm. If three or fewer patients achieve disease control, the study arm is stopped. Otherwise, 11 additional patients are accrued. If the DCR exceeds 7 of 25 patients, the null hypothesis is rejected for the respective study arm.

CONCLUSIONS

CRAFT was activated in October 2021 and will recruit at 10 centers in Germany.

TRIAL REGISTRATION NUMBERS

EudraCT: 2019-003192-18; ClinicalTrials.gov: NCT04551521.

[Preoperative diagnostics and typing of abdominal soft tissue sarcomas]

BACKGROUND

Abdominal sarcomas are a heterogeneous group of rare soft tissue tumors and can be localized intraperitoneally or retroperitoneally. A pretherapeutic differentiated subtyping is essential for planning an individual, multimodal treatment concept in an interdisciplinary team of experts.

OBJECTIVE

The central aspects of histology acquisition, imaging diagnostics and (molecular) pathological subtyping of abdominal soft tissue sarcomas are described in detail.

MATERIAL AND METHODS

Imaging and pathological diagnostics are depicted based on the German S3 guidelines on adult soft tissue sarcomas, a current literature search and personal experiences at the Sarcoma Center at the National Center for Tumor Diseases in Dresden (NCT/UCC).

RESULTS

Preoperative imaging and (molecular) pathological subtyping of abdominal soft tissue sarcomas place high demands on surgeons, radiologists and pathologists. Genome analyses of sarcomas have the potential to identify points of attack for individualized treatment options. The limitations of resectability can only be assessed by experienced sarcoma surgeons at specialized centers.

CONCLUSION

The treatment of abdominal soft tissue sarcomas at an experienced center is associated with a better prognosis. Even at the first suspicion of an abdominal sarcoma, a referral to an experienced center should be made in order to guarantee optimal expertise in diagnostics and treatment.

High tumour mutational burden and EGFR/MAPK pathway activation are therapeutic targets in metastatic porocarcinoma

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare skin cancer arising from the eccrine sweat glands. Due to the lack of effective therapies, metastasis is associated with a high mortality rate.

OBJECTIVES

To investigate the drivers of EPC progression.

METHODS

We carried out genomic and transcriptomic profiling of metastatic EPC (mEPC), validation of the observed alterations in an EPC patient-derived cell line, confirmation of relevant observations in a large patient cohort of 30 tumour tissues, and successful treatment of a patient with mEPC under the identified treatment regimens.

RESULTS

mEPC was characterized by a high tumour mutational burden (TMB) with an ultraviolet signature, widespread copy number alterations and gene expression changes that affected cancer-relevant cellular processes such as cell cycle regulation and proliferation, including a pathogenic TP53 (tumour protein 53) mutation, a copy number deletion in the CDKN2A (cyclin dependent kinase inhibitor 2A) region and a CTNND1/PAK1 [catenin delta 1/p21 (RAC1) activated kinase 1] gene fusion. The overexpression of EGFR (epidermal growth factor receptor), PAK1 and MAP2K1 (mitogen-activated protein kinase kinase 1; also known as MEK1) genes translated into strong protein expression and respective pathway activation in the tumour tissue. Furthermore, a patient-derived cell line was sensitive to EGFR and MEK inhibition, confirming the functional relevance of the pathway activation. Immunohistochemistry analyses in a large patient cohort showed the relevance of the observed changes to the pathogenesis of EPC. Our results indicate that mEPC should respond to immune or kinase inhibitor therapy. Indeed, the advanced disease of our index patient was controlled by EGFR-directed therapy and immune checkpoint inhibition for more than 2 years.

CONCLUSIONS

Molecular profiling demonstrated high TMB and EGFR/MAPK pathway activation to be novel therapeutic targets in mEPC.

[Situation of the German university pathologies under the constraints of the corona pandemic-evaluation of a first representative survey]

Die deutschen Universitätspathologien sind durch die Corona-Pandemie und die entsprechenden Maßnahmen in allen Bereichen betroffen. Hierzu wurde eine Umfrage unter den 36 Deutschen Universitätspathologien durchgeführt (Rücklauf 83 %) und ausgewertet. Die Ergebnisse sind zusammengestellt und erlauben eine Bewertung der aktuellen Situation; sie zeigen erhebliche Einschränkungen vor allem im wissenschaftlichen und diagnostischen Bereich und eine hohe Bereitschaft zur Covid Obduktionstätigkeit.

Multicenter validation of cancer gene panel-based next-generation sequencing for translational research and molecular diagnostics

The simultaneous detection of multiple somatic mutations in the context of molecular diagnostics of cancer is frequently performed by means of amplicon-based targeted next-generation sequencing (NGS). However, only few studies are available comparing multicenter testing of different NGS platforms and gene panels. Therefore, seven partner sites of the German Cancer Consortium (DKTK) performed a multicenter interlaboratory trial for targeted NGS using the same formalin-fixed, paraffin-embedded (FFPE) specimen of molecularly pre-characterized tumors (n = 15; each n = 5 cases of Breast, Lung, and Colon carcinoma) and a colorectal cancer cell line DNA dilution series. Detailed information regarding pre-characterized mutations was not disclosed to the partners. Commercially available and custom-designed cancer gene panels were used for library preparation and subsequent sequencing on several devices of two NGS different platforms. For every case, centrally extracted DNA and FFPE tissue sections for local processing were delivered to each partner site to be sequenced with the commercial gene panel and local bioinformatics. For cancer-specific panel-based sequencing, only centrally extracted DNA was analyzed at seven sequencing sites. Subsequently, local data were compiled and bioinformatics was performed centrally. We were able to demonstrate that all pre-characterized mutations were re-identified correctly, irrespective of NGS platform or gene panel used. However, locally processed FFPE tissue sections disclosed that the DNA extraction method can affect the detection of mutations with a trend in favor of magnetic bead-based DNA extraction methods. In conclusion, targeted NGS is a very robust method for simultaneous detection of various mutations in FFPE tissue specimens if certain pre-analytical conditions are carefully considered.

The German quality assurance system for the molecular-pathological detection of KRAS-mutations in colorectal cancer

4018

Background: In the beginning of 2008 the EMEA (European Medicines Agency) approved with panitumumab for the first time an EGFR (epidermal growth factor receptor) targeting therapy for patients with metastatic colorectal cancer overexpressing the EGFR and showing wildtypic sequences in the KRAS gene as a predictive biomarker. Thus, the need for assuring the quality of laboratories emerged. The German Society for Pathology in cooperation with the Federation of the German Pathologist supported by an unrestricted financial grant of Amgen Germany arranged a quality assurance system (QAS). In this context two round- robin tests were carried out which results are presented here. Methods: Collection of results from two round -robin tests and their statistical analysis applying binary classification tests. Results: Test sets of 4 histological sections from ten different cases of colorectal tumors with known mutational status of the KRAS gene were prepared for the round-robin tests. The method for the mutation detection was unrestricted. A total of 74 participants from universities (44 - 59.5 %) or other institutions (30 - 40.5 %) attended the tests. 11 participants (14.8 %) failed the test (6 universities: 13.6 %, 5 institutions: 16.6 %). For the analysis didesoxy-sequencing (DDS: 55 - 66.2 %), ARMS®-PCR (8 - 10.4 %), melting-point analysis (MPA: 7 - 9.1 %), pyrosequencing (PS: 6 - 7.8 %), hybridization (HYB: 4 - 5.2 %), or SSCP (1 - 1.3 %) were used, in which some participants (3) used more than one method. It turned out that all methods employed for the testing gave similar results when comparing the rate of correct or wrong hits or the rate of false positive detection: DDS (0.92, 0.07, 0.02), ARMS®-PCR (0.91, 0.08, 0.05), MPA (0.94, 0.06, 0.04), PS (0.95, 0.05, 0.03) or HYB (0.90, 0.10, 0.08). Conclusions: The quality of the molecular-pathological detection of KRAS mutations as precondition for an EGFR targeted therapy should be tested since about 15 % of laboratories did not meet a sufficient grade. For the mutation detection no method seemed superior.

[Table: see text]

Are overexpressed alternative survivin transcripts in human bladder cancer suitable targets for siRNA-mediated in vitro inhibition?

In order to reduce side effects of survivin-inhibiting anticancer therapies, we determined the expression of the survivin transcripts survivin-wild-type (survivin-wt), survivin-DeltaEx3 (DeltaEx3) and survivin-2B (2B) in cryo-preserved tumor and non-malignant bladder tissues (18 tumor and 22 non-malignant samples, including 17 autologous tissue pairs) by quantitative PCR. Furthermore, we investigated the biological effects following specific inhibition of the alternative transcripts DeltaEx3 and 2B in bladder cancer (BCa) cells. In BCa and non-malignant bladder tissues survivin-wt was the quantitatively dominant transcript followed by DeltaEx3 and 2B. The mean mRNA expression of DeltaEx3 (0.37 vs. 0.06 zmol/amol GAPDH, respectively) and 2B (0.13 vs. 0.01 zmol/amol GAPDH, respectively) was significantly higher in BCa compared to non-malignant bladder tissues, indicating their accessibility for an expression inhibition in BCa cells. Effective and long-lasting small interfering RNA-mediated inhibition of one alternative survivin transcript caused lower cell growth reduction effects (apoptosis induction, cell cycle arrest, colony formation) compared to simultaneous inhibition of multiple survivin transcripts including survivin-wt. Inhibition of one alternative survivin transcript increased the apoptosis rate by 11% vs. 33-46% when reducing several survivin transcripts. We observed no G2/M arrest or reduction of cell colony formation after inhibiting one alternative survivin transcript. Reduction of cell viability by the chemotherapeutics cisplatin, mitomycin C or gemcitabine was stronger in combination with inhibition of several survivin transcripts than in combination with the reduction of one alternative survivin splice variant. Furthermore, reducing one alternative transcript caused chemosensitization to only one chemotherapeutic agent in contrast to inhibition of several survivin transcripts. Therefore, the alternative survivin transcripts DeltaEx3 and 2B do not represent reasonable targets for anticancer, at least BCa, treatment.

[1-(11)C]acetate uptake is not increased in renal cell carcinoma

PURPOSE

The purpose of this study was to investigate the potential of [1-(11)C]acetate (AC) as a metabolic tracer for renal cell cancer in human subjects.

METHODS

Twenty-one patients with suspected kidney tumours were investigated with AC and dynamic PET. AC uptake was scored on a five-step scale. Tumour localisation was known from CT/MRI. Histology was available in 18/21 patients. The results in these 18 patients are reported.

RESULTS

AC uptake by the tumour was less than (n=11), equal to (n=5) or higher than (n=2) uptake in the surrounding renal parenchyma. Histological tumour types showed a typical distribution, with a predominance of clear cell carcinomas (n=14) and only a small number of papillary cell carcinomas (n=2) and oncocytomas (n=2). Only the benign oncocytomas were highly positive with AC.

CONCLUSION

In most kidney tumours the AC accumulation was not higher than in normal kidney parenchyma. Therefore, AC PET cannot be recommend for the characterisation of a renal mass.

Prognostic relevance of p53 and bcl-2 immunoreactivity for early invasive pT1/pT2 gastric carcinomas: indicators for limited gastric resections?

BACKGROUND

Laparoscopic or endoscopic limited resection is intended to be an additional therapeutic option for the treatment of early gastric cancer. However, tumorbiologic markers to predict the outcome for patients after limited resections are missing. This study therefore investigated the prognostic relevance of p53 and bcl-2 immunoreactivity as well as the percentage of apoptotic tumor cells in early invasive pT1/pT2 tumors managed with standard operations for gastric adenocarcinoma.

METHODS

Histologic slides of 65 pT1/pT2 gastric carcinomas were investigated for bcl-2 and p53 immunoreactivity. For 35 patients, DNA fragmentation of tumor cell nuclei was determined by the terminal uridine 5'-triphosphate (UTP) nick end-labeling (TUNEL) method. Follow-up evaluation of the patients was prospectively documented for 53.4 +/- 4.1 months.

RESULTS

Findings showed that bcl-2 immunoreactivity was associated with tumors of the intestinal type according to Lauren s classification (p = 0.042), and that p53 immunoreactivity was increased in more invasive tumors (pT1 vs pT2 tumors; p = 0.047). Mean survival time was significantly longer for patients with bcl-2-negative tumors (74.3 +/- 6.8 months) than for patients with bcl-2-positive tumors (50.8 +/- 7.6 months; p = 0.024). The percentage of apoptotic tumor cell nuclei did not have prognostic relevance in the population studied and was not associated with several histopathologic parameters or bcl-2 and p53 immunoreactivity. Subgroup analysis indicated that the survival of patients with differentiated G2 and bcl-2-negative/p53-negative tumors was significantly longer (82 +/- 6 months) than the survival of patients with G2 bcl-2- and/or p53-positive tumors (41.8 +/- 12.5 months; p = 0.005), with independent prognostic relevance determined by multivariate analysis (p = 0.024).

CONCLUSION

The data reported indicate that the analysis of bcl-2 and p53 immunoreactivity seems to have prognostic implications for early invasive (pT1/pT2) gastric adenocarcinomas and may subclassify patients for minimally invasive laparoscopic or endoscopic gastric resections.

Detection of occult high graded microsatellite instabilities in MMR gene mutation negative HNPCC tumors by addition of complementary marker analysis

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant tumor syndrome predisposing to predominantly colorectal and endometrial cancer. In 90% of the cases, molecular analyses reveal microsatellite instabilities due to germline mutations in DNA mismatch repair (MMR) genes, mainly MLH1, MSH2, among these tumors.

PATIENTS AND METHODS

Tumors from 40 HNPCC index patients (31 Amsterdam positive, 9 Bethesda positive; 21 females, 19 males; mean age 48.0 +/- 13.2 years) were examined. In contrast to the classical constellation, their tumors revealed only a microsatellite stable (MSS, n=31)--or low instable (MSI-L, n=9)--tumor phenotype following the international reference panel of 5 microsatellites. No MLH1 and MSH2 mutations were detectable. Complementary microsatellites (BAT40, D10S197, D13S153, D18S58, MYCL1) were investigated by PCR and fragment analysis to find other instabilities which might hint to the MIN-pathway of the tumors.

RESULTS

Due to ten microsatellites in total tumors were now reclassified in 4 MSI-H (10%), 24 MSI-L (60%) and 12 in MSS (30%) phenotypes. The mean age of onset for CRCs was the lowest in the MSI-H group with 45.7 +/- 9.6 years (vs. 48.7 +/- 14.3 and 49.0 +/- 12.9 years in MSI-L and MSS group). MSI-H-and MSI-L tumors were often localized in the proximal colon (50 and 52%), whereas MSS tumors were preferentially localized in the distal colon (77%). -

CONCLUSION

Complementary microsatellites help to subdive "non-classical" HNPCC in subgroups with different clinical appearance. It allows to detect occult MSI-H tumors with up to 10% and to confirm MSS tumors who seem to have a similar biological behaviour like sporadic CRC. Maybe that this genetic reclassification influence the decision of whether to offer patients chemotherapy or not, since it is known that patients with instable tumors do not benefit from chemotherapy as well as patients with microsatellite stable tumors.

Severe pulmonary hypertension in chronic idiopathic myelofibrosis

BACKGROUND

Chronic myeloproliferative disorders (CMPD) seem to be associated with an increased risk for pulmonary hypertension (PH).

CASE REPORT

A patient with history of chronic idiopathic myelofibrosis (CIMF) presented with progressive dyspnea (New York Heart Association class III). Until this time he had not received specific treatment for CIMF. Echocardiography and rightheart catheterization confirmed PH. Further diagnostic procedures excluded a specific cause of PH. Therefore, primary PH was assumed. 2 years later he presented again with progressive dyspnea due to a progress of PH. A few days later the patient died from acute posterior myocardial infarction. Pathologic examination of the lung showed an obstruction of the small vessels by conglomerates of megakaryocytes.

DISCUSSION

We conclude that PH developed secondarily due to CMPD. PH should be suspected in patients with CMPD and should influence the decision for treatment of CMPD.

Low-level microsatellite instability phenotype in sporadic glioblastoma multiforme

PURPOSE

Genetic instability is a hallmark of glioblastoma multiforme (GBM). Microsatellite instability (MSI) is a significant event in the tumorigenesis of many sporadic malignancies. The aim of our investigation was to study microsatellite instability in newly diagnosed glioblastomas.

METHODS

MSI was investigated in 109 GBMs with 15 microsatellite markers. Immunohistochemistry was performed for the mismatch repair (MMR) proteins hMLH1, hMSH2, hPMS2, and hMSH6 in cases showing MSI. Sequence and promoter methylation status of hMLH1 were analyzed in the case of a decreased hMLH1 protein expression as well. To further investigate MSI(+) GBMs we carried out studies of LOH at selected chromosome regions, EGFR amplification, and sequence of p53 and PTEN.

RESULTS

MSI was observed in six GBMs (5.5%) and it was more frequent in GBMs with a previous lower grade astrocytoma (18.8% vs. 3.2%). MMR protein staining was positive in all MSI(+) GBMs except in one case, which showed an aberrant expression of hMLH1 and hPMS2 without hMLH1 inactivation. Among MSI(+) GBMs, one tumor corresponded to the GBM molecular type 1 (p53 mutation, no EGFR amplification), another tumor to type 2 (wild-type p53, EGFR amplification), and four tumors to neither type (wild-type p53, no EGFR amplification). None of the six tumors carried a PTEN mutation.

CONCLUSIONS

MSI in GBM might be caused by inactivation of minor MMR genes rather than by a deficiency of hMLH1 or hMSH2 and it appears not to play a decisive role in the pathogenesis of these tumors. MSI(+) GBMs predominantly showed a profile which included wild-type of p53 and PTEN and absence of EGFR amplification but MSI occurred in all GBM molecular subtypes.

Extended microsatellite analysis in microsatellite stable, MSH2 and MLH1 mutation-negative HNPCC patients: genetic reclassification and correlation with clinical features

BACKGROUND

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant disorder predisposing to predominantly colorectal cancer (CRC) and endometrial cancer frequently due to germline mutations in DNA mismatch repair (MMR) genes, mainly MLH1, MSH2 and also MSH6 in families seen to demonstrate an excess of endometrial cancer. As a consequence, tumors in HNPCC reveal alterations in the length of simple repetitive genomic sequences like poly-A, poly-T, CA or GT repeats (microsatellites) in at least 90% of the cases.

AIM OF THE STUDY

The study cohort consisted of 25 HNPCC index patients (19 Amsterdam positive, 6 Bethesda positive) who revealed a microsatellite stable (MSS)--or low instable (MSI-L)--tumor phenotype with negative mutation analysis for the MMR genes MLH1 and MSH2. An extended marker panel (BAT40, D10S197, D13S153, D18S58, MYCL1) was analyzed for the tumors of these patients with regard to three aspects. First, to reconfirm the MSI-L phenotype found by the standard panel; second, to find minor MSIs which might point towards an MSH6 mutation, and third, to reconfirm the MSS status of hereditary tumors. The reconfirmation of the MSS status of tumors not caused by mutations in the MMR genes should allow one to define another entity of hereditary CRC. Their clinical features were compared with those of 150 patients with sporadic CRCs.

RESULTS

In this way, 17 MSS and 8 MSI-L tumors were reclassified as 5 MSS, 18 MSI-L and even 2 MSI-H (high instability) tumors, the last being seen to demonstrate at least 4 instable markers out of 10. Among all family members, 87 malignancies were documented. The mean age of onset for CRCs was the lowest in the MSI-H-phenotyped patients with 40.5 +/- 4.9 years (vs. 47.0 +/- 14.6 and 49.8 +/- 11.9 years in MSI-L- and MSS-phenotyped patients, respectively). The percentage of CRC was the highest in families with MSS-phenotyped tumors (88%), followed by MSI-L-phenotyped (78%) and then by MSI-H-phenotyped (67%) tumors. MSS tumors were preferentially localized in the distal colon supposing a similar biologic behavior like sporadic CRC. MSH6 mutation analysis for the MSI-L and MSI-H patients revealed one truncating mutation for a patient initially with an MSS tumor, which was reclassified as MSI-L by analyzing the extended marker panel.

CONCLUSION

Extended microsatellite analysis serves to evaluate the sensitivity of the reference panel for HNPCC detection and permits phenotype confirmation or upgrading. Additionally, it confirms the MSS status of hereditary CRCs not caused by the common mutations in the MMR genes and provides hints to another entity of hereditary CRC.

[Midterm results after treatment of liposarcoma in the extremities]

PURPOSE

In this retrospective analysis, survival time, local recurrence and rate of metastasis were appraised in patients with primary liposarcoma of the extremities depending upon the applied primary and adjuvant therapy procedures. Furthermore, we compared the representativity of histological results of the biopsy with the final histology of the resected tumour.

MATERIAL AND METHOD

Between 1990 and 1998, 27 patients were surgically treated who suffered from a primary liposarcoma of the extremities. At the mean follow-up time of 62.4 months (39-141 months) postoperative survival rate, rate of metastasis and local recurrence were determined. The results were analysed with regard to intraoperative resection distance, tumour size and localisation as well as histological classification of previous biopsy and finally resected tumour. The influence of radiotherapy on the results was also determined.

RESULTS

In 5 patients (18.5%) the amputation and in 22 cases (81.5%) the limb sparing resection of the liposarcoma was performed. 6 patients underwent a marginal resection and one patient an intralesional resection. At follow-up we observed a local recurrence rate of 22.2% (n = 6) and a survival rate of 74.1%. 18.5% of the patients had metastases. After adjuvant radiotherapy three patients (50%) showed local recurrence after marginal resection. In only 8 cases (29.6%) the results of primary biopsy and final tumour classification (entity, subtype and grading) were identical.

CONCLUSION

The development of metastases (often pulmonary) and local recurrences even after long tumour-free interval makes adequate follow-up investigations mandatory in liposarcoma patients. With regard to the problems in assessing liposarcoma biopsies, MRI-orientated biopsies from several tumour areas via one biopsy approach are recommended.

Extramedullary blast crisis of chronic myeloid leukemia after allogeneic hematopoietic stem cell transplantation mimicking aggressive, translocation t(14;18)-positive B-cell lymphoma

We report the case of a 42-year-old male patient who was diagnosed with a large tumor of the right thoracic aperture 30 months after unrelated hematopoietic stem cell transplantation (HSCT) for accelerated phase of Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML). Biopsy revealed an immature lymphoid neoplasia with blastic tumor cell morphology and immunoreactivity for CD34, CD79a, CD43, and CD30 as well as slight positivity for TdT and CD20. Bcr-Abl rearrangement was found in interphase tumor cell nuclei by fluorescence in situ hybridization (FISH). Furthermore, a translocation t(14;18)(q32;q21) was amplified by polymerase chain reaction (PCR). Bone marrow (BM) examination showed regular hematopoiesis including a negative FISH analysis for Bcr-Abl and complete donor chimerism. Nested PCR from peripheral blood (PB), but not conventional PCR, was positive for the b3a2 Bcr-Abl transcript. Neither radiation nor intensive chemotherapy was capable of achieving a tumor remission, and the patient died from progressive disease 6 months later. Postmortem examinations showed a shift of immunophenotype with appearance of myeloperoxidase-positive tumor cells and loss of lymphoid antigens. In addition, there were characteristic cytogenetic findings of multiple Ph chromosomes and a clonal loss of P53 tumor suppressor gene. The latter was already deleted before HSCT. We conclude that lymphoid neoplasia occurring in our patient should be interpreted as an extramedullary, very immature blast crisis of CML expressing lymphoid differentiation markers rather than a true de novo NHL.

Tissue factor deficiency causes cardiac fibrosis and left ventricular dysfunction

Exposure of blood to tissue factor (TF) activates the extrinsic (TF:FVIIa) and intrinsic (FVIIIa:FIXa) pathways of coagulation. In this study, we found that mice expressing low levels of human TF ( approximately 1% of wild-type levels) in an mTF(-/-) background had significantly shorter lifespans than wild-type mice, in part, because of spontaneous fatal hemorrhages. All low-TF mice exhibited a selective heart defect that consisted of hemosiderin deposition and fibrosis. Direct intracardiac measurement demonstrated a 30% reduction (P < 0.001) in left ventricular function in 8-month-old low-TF mice compared with age-matched wild-type mice. Mice expressing low levels of murine FVII ( approximately 1% of wild-type levels) exhibited a similar pattern of hemosiderin deposition and fibrosis in their hearts. In contrast, FIX(-/-) mice, a model of hemophilia B, had normal hearts. Cardiac fibrosis in low-TF and low-FVII mice appears to be caused by hemorrhage from cardiac vessels due to impaired hemostasis. We propose that TF expression by cardiac myocytes provides a secondary hemostatic barrier to protect the heart from hemorrhage.

Myomectomy as a pregnancy-preserving option in the carefully selected patient

OBJECTIVES

To present the indications for myomectomy during pregnancy and to discuss complications possibly related and unrelated to the procedure.

METHOD AND RESULTS

A 33-year-old patient at 18 weeks of gestation underwent removal of a 1,570-gram symptomatic fundic myoma. Histologically the patient had a leiomyomatous neoplasm of uncertain malignant potential. The pregnancy was continued under sequential observation with magnetic resonance imaging and ultrasound. At 36 weeks of gestation a healthy girl with an upper extremity limb defect was born via cesarean section. Follow-up of the mother and the child was uneventful.

CONCLUSIONS

Certain known risk factors in pregnant women with myomas can predispose to complications during pregnancy. Women with such risk factors or women who have failed medical therapy should be offered the option of undergoing myomectomy as a pregnancy-preserving procedure.

Sixteen rare sequence variants of the hMLH1 and hMSH2 genes found in a cohort of 254 suspected HNPCC (hereditary non-polyposis colorectal cancer) patients: mutations or polymorphisms?

5-8% of all colorectal cancer cases are assumed to be due to germline mutations in DNA mismatch repair genes. Mutation analysis of these genes in affected families enables one to identify subjects with an inborn susceptibility to colorectal tumorogenesis and to offer presymptomatic testing to family members at risk, provided that the mutation detected is a truncating one or a missense mutation that has either been judged as disease causing in other families or segregates with the disease and results in a microsatellite instability of the corresponding tumor. Segregation analysis within the family or microsatellite analysis of the tumor is, however, not always possible. In these cases, assessment of the relevance of the sequence variation identified is very difficult. On the other hand, discrimination between inactivating mutations and innocuous sequence polymorphisms is of extreme importance for clinical and genetic counseling of affected families. Here we report 16 rare sequence variants of the hMLH1 and hMSH2 genes including 11 different missense variations found in a cohort of 254 suspected HNPCC patients. We provide evidence, that missense variations in hMLH1 do not necessarily result in microsatellite instability of the corresponding tumor DNA. These patients would have been missed had one followed the recommendations of using only microsatellite analysis for the selection of patients at high risk of hereditary non-polyposis colorectal cancer for mutation analysis.

Prognostic factors and long-term results after surgery for gallbladder carcinoma: a retrospective study of 127 patients

BACKGROUND

The surgical management of gallbladder cancer is controversial, especially as to the indications for reoperation, extended resection, and aggressive treatment in advanced tumor stages.

METHODS

Records and follow-ups of 127 patients with gallbladder carcinoma who underwent surgery between 1980 and 1997 were examined according to the pTNM and Nevin staging systems. Factors predictive for survival were obtained from histopathologic staging and surgical procedures.

RESULTS

Surgery for gallbladder cancer was associated with an overall 5-year survival rate of 6.6%. Curative resection was possible in 35.5% of cases, which resulted in 5-year survival rates of 20%. Noncurative surgery revealed poor prognosis, with median survival time limited to 3.2 months, independently of macroscopic or microscopic tumor residues. None of the latter patients survived longer than 24 months. Surgery of stage I/II cancer showed a 5-year survival rate of 64.5%. In stage III/IV tumors, resectability was only 20.4%. However, curative surgery in advanced stages significantly increased median survival from 3.2 to 19.4 months.

CONCLUSIONS

Only complete tumor resection can provide long-term survival, even in advanced stages. Because negative surgical margins and UICC stage are the strongest predictors for survival, reoperation is required with all incidental findings above the T1b stage.

Hepatitis C virus-specific CD4+ T cell response after liver transplantation occurs early, is multispecific, compartmentalizes to the liver, and does not correlate with recurrent disease

The role of hepatitis C virus (HCV)-specific CD4+ T cells in recurrent HCV infection after orthotopic liver transplantation (OLTx) is unclear. In parallel, 73 intrahepatic and 73 blood-derived T cell lines were established from 34 patients. At a single cell level, virus-specific interferon (IFN)-gamma production to various HCV proteins was determined by ELISPOT assay: 45 (62%) of 73 liver- or blood-derived T cell lines produced IFN-gamma in response to one of the HCV antigens. HCV specificity was detected mainly in the liver (47% vs. 23% in the blood; P<.05, chi(2) test) and was detectable earlier (< or =6 months) significantly more often than later (>6 months) after OLTx (78% vs 49%; P<.05, chi(2) test). Histology, histologic activity index, liver enzymes, and virus load did not correlate with the occurrence of HCV-specific CD4+ T cells. Despite strong immunosuppressive treatment, OLTx recipients can develop an early, multispecific, preferentially intrahepatic CD4+ T cell response that decreases over time, making it a potential candidate target for novel therapeutic approaches in the transplant setting.

Liver-derived hepatitis C virus (HCV)-specific CD4(+) T cells recognize multiple HCV epitopes and produce interferon gamma

Virus-specific CD4(+) T-cell response at the site of inflammation is believed to play a decisive role for the course of viral disease. In hepatitis C virus (HCV) infection, the majority of studies focused on the peripheral blood T-cell response. In this study we analyzed intrahepatic virus-specific CD4(+) T-cell response and compared this with that in the peripheral blood. Liver and blood-derived T-cell lines were studied in 36 patients (18 with chronic hepatitis C and 18 with HCV-associated cirrhosis). Virus-specific interferon gamma (IFN-gamma) production at a single cell level to various HCV-proteins (core, nonstructural [NS] 3/4, NS5) were determined by enzyme-linked immunospot (ELIspot). Phenotyping was done by fluorescent-activated cell sorter analysis. In approximately half (16 of 36 [44%]) of intrahepatic T-cell lines a significant number of IFN-gamma spots were observed, whereas this was the case in only 19% (7 of 36 T-cell lines) in the blood. In relative terms, core and nonstructural proteins were recognized with the same frequency in both compartments, but HCV-specificity was significantly more often detected in liver tissue compared with the blood. Hepatitis activity index, viral load, and alanine transaminase levels did not correlate with the detection of HCV-specific CD4(+) T cells. All T-cell lines were dominated by CD4(+) T cells. In conclusion, HCV-specific CD4(+) T cells are multispecific, compartmentalize to the liver, and produce IFN-gamma. We speculate that our data would support the concept of compartmentalization of specific T cells at the site of inflammation and that a low frequency of specific T cells is associated with failure to clear the virus and a chronic course of disease.

Novel germline mutation (300-305delAGTTGA) in the human MSH2 gene in hereditary non-polyposis colorectal cancer (HNPCC)

Hereditary non-polyposis colorectal cancer (HNPCC) is a common hereditary syndrome characterized by the high incidence and early onset of colorectal cancer. The majority of the HNPCC families carry germline mutations in either the MSH2 or the MLH1 mismatch repair gene. A 46 year-old female patient whose family history fulfilled the Amsterdam criteria for HNPCC was diagnosed with undifferentiated adenocarcinoma of the transverse colon. Recognizing the Lynch 2 syndrome (the existance of multiple HNPCC related cancers in a pedigree), we used polymerase chain reaction followed by direct sequencing to screen the coding regions of both the MSH2 and the MLH1 genes for germline mutations in DNA from the patient. We detected a novel germline mutation (300-305delAGTTGA) in exon 2 of human MSH2. We noted microsatellite instability in four microsatellite loci. Immunohistochemistry showed a lack of expression of the MSH2 gene product in the tumor, suggesting that the mutation is a disease-causing mutation.

Prognostic significance of apoptosis and associated factors in oral squamous cell carcinoma

Tumour progression is characterised by an imbalance between cell proliferation and apoptosis. The aim of our study was to estimate the importance of proliferation and apoptosis associated parameters in primary squamous cell carcinomas (SCCs) of the oral cavity and oropharynx. For determination of apoptosis, the enzymatic labelling of DNA fragmentation with a terminal transferase reaction was used in 156 tissue samples of 107 patients, including corresponding lymph-node metastases in nine cases. P53, bcl-2, and Ki-67 were determined immunohistologically. P53 was detectable in 50.5% of the cases. Positive staining was associated significantly with decreased apoptosis (P<0.003). Bcl-2 was upregulated in 31.8% of the cases depending on the tumour grading (P<0.001) and correlated negatively with apoptosis (P<0.001). Proliferation (P<0.006) and apoptosis (P<0.03) were enhanced in larger tumours, though a direct correlation between these two parameters was not proven. Nevertheless, in contrast to the conventional tumour staging and grading, neither the expression of p53 or bcl-2 nor the apoptosis or Ki-67 measurements were able to predict survival or recurrence-free survival of the patients suffering from a SCC in the oral cavity or oropharynx. Our observations suggest that the function of wild-type p53 to induce apoptosis is lost in at least half of the SCCs under study and that the physiological function of bcl-2 as potent inhibitor of apoptosis is widely preserved in oral SCC.

Myocardial gene transfer by selective pressure-regulated retroinfusion of coronary veins

Catheter-based percutaneous transluminal gene delivery (PTGD) into the coronary artery still falls behind the expectations of an efficient myocardial gene delivery system. In this study gene delivery was applied by selective pressure-regulated retroinfusion through the coronary veins to prolong adhesion of replication defective adenovirus within the targeted myocardium. Adenoviral vectors consisted either of luciferase (Ad.rsv-Luc) or beta-galactosidase (Ad.rsv-betaGal) reporter gene under control of an unspecific promotor derived from the Rous sarcoma virus (RSV). In this pig model, selective retrograde gene delivery into the anterior cardiac vein during a brief period of ischemia substantially increased reporter gene expression in the targeted myocardium (LAD region) compared with antegrade delivery as a control. Repeated retrograde delivery during two periods of brief ischemia resulted in a more homogeneous transmural expression predominantly observed in cardiomyocytes (X-gal-staining). In the nontargeted myocardium (CX region) there was no evidence for adenoviral transfection. From our data we infer that selective pressure-regulated retroinfusion is a promising approach for efficient percutaneous transluminal gene delivery to the myocardium. Gene Therapy (2000) 7, 232-240.