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Biomedical subjects

G Leder

Publications and source records attributed to G Leder.

78 records · Page 5Linked to original sources

Surgery and multimodal treatments in pancreatic cancer--a review on the basis of future multimodal treatment concepts.

BACKGROUND: To improve the surgical outcome after resection of pancreatic adenocarcinomas, multimodal treatment concepts need to be applied and improved. In spite of several positive studies, and the fact that multimodality treatment is the standard concept in major centers for pancreatic cancer surgery, a recent trial shed some doubt on the positive effect of adjuvant radiochemotherapy, so that the majority with reservations about multimodal treatment feel confirmed in their opinion that surgical treatment alone is sufficient therapy for resectable pancreatic cancer. The controversy among those for and against adjuvant treatment need an up-to-date review of the indications and results achievable with various treatment modalities. PATIENTS/METHODS: The literature on the indications and results of adjuvant/neoadjuvant therapies in pancreatic cancer was reviewed to provide a solid base for current recommendations and future developments. A special view was concentrated on the biology of the disease in the spontaneous course, after surgery and during/after various palliative and adjuvant/neoadjuvant treatment modalities, to characterize the disease for an optimally targeted treatment in conjunction with surgical removal of the tumor. The results of systemic and regional chemotherapy and radiotherapy either alone or in combination, before, during, and after surgery, were critically analyzed with respect to the oncological possibilities and pitfalls of each treatment method. RESULTS: In two randomized trials, one testing postoperative radiochemotherapy (GITSG), and one postoperative chemotherapy (Bakkevold), the adjuvant treatment achieved a significant prolongation of the median survival time. The 5- and 10-year survival rates were improved in the GITSG study. The EORTC-GITCCG trial could not confirm the benefit of adjuvant radiochemotherapy. This study had a different design than the GITSG trial. Several historical control studies supported the beneficial effect of postoperative radiochemotherapy. In three historical control trials using regional chemotherapy, one with intraoperative radiotherapy, the survival times were improved vs. surgery alone. Intraoperative or postoperative radiotherapy as single modalities might reduce local relapses, but a survival advantage is still debated. Preoperative neoadjuvant radiochemotherapy has several advantages (downstaging, devitalizing margins and lymph node metastases, compatibility of treatment vs. postoperative radiochemotherapy), and does not seem to increase the postoperative morbidity. Several trials have confirmed the feasibility of this concept, but no survival advantage has yet been proven. Systemic and regional chemotherapy is able to downstage primarily nonresectable pancreatic cancers. CONCLUSIONS: Postoperative adjuvant radiochemotherapy with up-to-date protocols can be recommended for routine treatment, if the surgeon or the patient desires to improve the usually remote prognosis after surgery alone. For those being undecisive or against adjuvant therapy, the participation in trials, e.g., ESPAC 1 and 2 studies, is strongly recommended. Regarding our own positive experience with adjuvant regional chemotherapy and in view of the postresectional progression pattern, we currently favour adjuvant radiochemotherapy, with the chemotherapy delivered regionally via the celiac axis. This concept will be tested vs. surgery alone in the ESPAC 2 trial. Neoadjuvant therapies have a great potential, but should be conducted within studies, such as pre-, intra-, or postoperative radiotherapy.

Adenocarcinoma↗

Resection and radiochemotherapy of pancreatic cancer--the future?

BACKGROUND: To improve the surgical outcome after resection of pancreatic adenocarcinomas, multimodal treatment concepts need to be applied and improved. The controversies among those being pro and contra adjuvant treatment need an up-to-date review of the indications and results achievable with various treatment modalities. PATIENTS/METHODS: The literature regarding the indications and results of adjuvant/neoadjuvant therapies in pancreatic cancer was reviewed to provide a solid base for current recommendations and future developments. The biology of the disease in the spontaneous course, after surgery and during/after various palliative and adjuvant/neoadjuvant treatment modalities was focussed on, to characterise the disease for an optimally targeted treatment in conjunction with surgical removal of the tumour. The results of systemic and regional chemotherapy and radiotherapy, either alone or in combination, before, during and after surgery were critically analysed with respect to the oncological possibilities and pitfalls of each treatment method. RESULTS: In two randomised trials, one testing postoperative radiochemotherapy (GITSG), and one postoperative chemotherapy, the adjuvant treatment achieved a significant prolongation of the median survival time. The 5-year and 10-year survival rates were improved in the GITSG study. The EORTC-GITCCG trial could not confirm the benefit of adjuvant radiochemotherapy. This study had a different design than the GITSG trial. Several historical control studies supported the beneficial effect of postoperative radiochemotherapy. In three historical control trials using regional chemotherapy, one with intraoperative radiotherapy, the survival times were improved compared with surgery alone. Intraoperative or postoperative radiotherapy as single modalities might reduce local relapses, but a survival advantage is still debated. Preoperative neoadjuvant radiochemotherapy has several advantages (downstaging, devitalising margins and lymph node metastases, compatibility of treatment vs. postoperative radiochemotherapy), and does not seem to increase the postoperative morbidity. Several trials have confirmed the feasibility of this concept, but no survival advantage has yet been proven. Systemic and regional chemotherapy is able to downstage primarily nonresectable pancreatic cancers. CONCLUSIONS: Postoperative adjuvant radiochemotherapy with up-to-date protocols can be recommended for routine treatment, if the surgeon or the patient desires to improve the usually remote prognosis after surgery alone. For those being indecisive or against adjuvant therapy, the participation in trials, e.g. the ESPAC 1 and 2 studies, is strongly recommended. Regarding our own positive experience with adjuvant regional chemotherapy and in view of the postresectional progression pattern, we currently favour adjuvant radiochemotherapy, with the chemotherapy delivered regionally via the celiac axis. This concept will be tested against surgery alone in the ESPAC 2 trial. Neoadjuvant therapies have a great potential, but should be conducted within studies, such as pre-, intra-, or postoperative radiotherapy.

Adenocarcinoma↗

Host immune response in renal cell cancer: interleukin-4 (IL-4) and IL-10 mRNA are frequently detected in freshly collected tumor-infiltrating lymphocytes.

Human renal cell cancer (RCC) is clearly responsive to immunotherapy. Clinical responses may be mediated by "non-specific" (e.g. natural killer, NK, cells) or "specific" MHC-class-I-restricted tumor-specific CD8+ T lymphocytes. Typically RCC progresses, however, despite significant infiltration of various lymphoid cells. We examined freshly isolated RCC tumor-infiltrating lymphocytes (TIL) derived from seven RCC patients for cytokine expression by the polymerase chain reaction (PCR). Established RCC tumor cell lines derived from these RCC patients were negative for interleukin-2 (IL-2), IL-4, IL-10, and interferon gamma and found to be positive for tumor necrosis factor alpha (TNF alpha), IL-6, IL-1 beta, granulocyte/macrophage-colony-stimulating factor (GM-CSF), and transforming growth factor beta 1 (TGF beta 1) message as detected by PCR. An identical pattern of cytokine mRNA expression was identified in other long-term RCC lines and in normal human kidney cells upon culture, but not in two Wilms tumor cell lines tested. Short-term-, and long-term-established RCC lines, but not Wilms tumor lines, secreted substantial levels of GM-CSF, TNF alpha, IL-1 beta, and IL-6 as detected by enzyme-linked immunosorbent assay. Both RCC lines and Wilms tumor lines secreted TGF beta 1. In comparison, normal kidney cells secreted IL-6 and GM-CSF, but not IL-1 beta, or TFG beta 1 under identical in vitro cell culture conditions. We applied PCR-based methods to characterize the cytokine mRNA expression pattern in immune cells infiltrating into renal cell cancer without the need for expansion of such effector cells in vitro. Examining freshly collected RCC TIL by PCR from patients with primary cell cell cancer, we could demonstrate that such cells, but not lympho-mononuclear cells harvested from normal human kidney tissue, typically exhibit IL-4 and IL-10 mRNA expression.

Base Sequence↗

Which granules can be stained with azure B and eosin?

The standardized stain composed of pure azure B and eosin, as published by Wittekind and colleagues in 1986, demonstrated granules in neutrophilic leucocytes that were much coarser than those seen after staining with conventional Romanowsky-Giemsa methods. These granules belong to at least two classes. Their identification cannot be achieved by means of the morphologic characteristics of single granules; a multivariate analysis of the granulation as a whole, and a comparison with specifically stained primary granules is required. In particular, this study on unbiased cell samples showed that with Wittekind's method, the primary granules in peripheral neutrophils are stained. Further study of clinical smears revealed an enhanced dye uptake by the secondary granules. The staining behavior of the granules is related to the leukocyte count.

Azure Stains↗

In vitro concentration response studies and in vitro phase II tests as the experimental basis for regional chemotherapeutic protocols.

The theoretical pharmacologic benefit of regional vs. systemic chemotherapy is defined and the concentration response behavior of cytostatic drugs and their optimal exposure times are described with human cancer cell lines (HT29, NMG64/84) and fresh human tumor cell suspensions in the human tumor colony assay (HTCA). The theoretical pharmacological advantages are 5.8 to 6 for adriamycin (ADM), 8 for cisplatinum (CDDP), 6.3 for epidoxorubicin (EPI), 22 to 58 for 5-fluorouracil (5FU), 4.6 for mitomycin C (MMC), and 6.3 for mitoxantrone (NOV). The drugs differed in their cytotoxic potency in vitro and thus also potential efficacy for regional chemotherapy; however, all but 5-fluorodeoxyuridine (5FUDR) exerted cytotoxicity dependent on exposure time and concentration. On average, elevation of the test concentrations by 1 lg doubled responses in fresh human tumor cell suspensions. From these results and clinical considerations, optimal times were defined for the regional chemotherapy strategies of hepatic artery infusion, intraperitoneal instillation, and chemoembolisation as performed at our institution.

Antineoplastic Agents↗