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Background: To test the effect of variant histology relative to urothelial histology on stage at presentation, cancer specific mortality (CSM) and overall mortality (OM) after chemotherapy use, in urethral cancer.
Materials and Methods: Within the Surveillance, Epidemiology and End Results (2004–2016) database, we identified 1,907 primary variant histology urethral cancer patients. Kaplan-Meier plots, Cox regression analyses, cumulative incidence-plots, multivariable competing-risks regression models and propensity score matching for patient and tumor characteristics were used.
Results:Of 1,907 eligible urethral cancer patients, urothelial histology affected 1,009 (52.9%) vs. squamous cell carcinoma (SCC) 455 (23.6%) vs. adenocarcinoma 278 (14.6%) vs. other histology 165 (8.7%) patients. Urothelial histological patients exhibited lower stages at presentation than SCC, adenocarcinoma or other histology patients. In urothelial histology patients, five-year CSM was 23.5% vs. 34.4% in SCC (Hazard Ratio (HR) 1.57) vs. 40.7% in adenocarcinoma (HR 1.69) vs. 43.4% in other histology (HR 1.99, p<0.001). After matching in multivariate competing-risks regression models, variant histology exhibited 1.35-fold higher CSM than urothelial. Finally, in metastatic urethral cancer, lower OM was recorded after chemotherapy in general, including metastatic adenocarcinoma and other variant histology subtypes, except metastatic SCC.
Conclusion: Adenocarcinoma, SCC and other histology subtypes affect fewer patients than urothelial histology. Presence of variant histology results in higher CSM. Finally, chemotherapy for metastatic urethral cancer improves survival in adenocarcinoma and other variant histology subtypes, but not in SCC.
Despite the success of immune checkpoint blockade in cancer, the number of patients that benefit from this revolutionary treatment option remains low. Therefore, efforts are being undertaken to sensitize tumors for immune checkpoint blockade, which includes combining immune checkpoint blocking agents such as anti-PD-1 antibodies with standard of care treatments. Here we report that a combination of chemotherapy (doxorubicin) and immune checkpoint blockade (anti-PD-1 antibodies) induces superior tumor control compared to chemotherapy and immune checkpoint blockade alone in the murine autochthonous polyoma middle T oncogene-driven (PyMT) mammary tumor model. Using whole transcriptome analysis, we identified a set of genes that were upregulated specifically upon chemoimmunotherapy. This gene signature and, more specifically, a condensed four-gene signature predicted favorable survival of human mammary carcinoma patients in the METABRIC cohort. Moreover, PyMT tumors treated with chemoimmunotherapy contained higher levels of cytotoxic lymphocytes, particularly natural killer cells (NK cells). Gene set enrichment analysis and bead-based ELISA measurements revealed increased IL-27 production and signaling in PyMT tumors upon chemoimmunotherapy. Moreover, IL-27 signaling improved NK cell cytotoxicity against PyMT cells in vitro. Taken together, our data support recent clinical observations indicating a benefit of chemoimmunotherapy compared to monotherapy in breast cancer and suggest potential underlying mechanisms.
Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality. In a cohort of 189 patients with CRC, we recently showed that expression of the cytoskeletal scaffolding protein non-erythroid spectrin αII (SPTAN1) was lower in advanced metastatic tumours. The aim of the present study was to clarify the association of intratumoural SPTAN1 expression levels with treatment and survival outcomes in patients with CRC. The analysis was based on histologic assessment of SPTAN1 protein levels in our own CRC cohort, and transcriptome data of 573 CRC cases from The Cancer Genome Atlas (TCGA). We first establish that high intratumoural levels of SPTAN1 protein and mRNA associate with favourable survival outcomes in patients with CRC. Next, a response prediction signature applied to the TCGA data reveals a possible link between high SPTAN1 transcript levels and improved patient responses to FOLFOX chemotherapy. Complementary in vitro experiments confirm that SPTAN1 knockdown strains of the colon cancer cell lines HT-29, HCT116 mlh1-2 and Caco-2 are less responsive to FOLFOX chemotherapy compared with SPTAN1-proficient control strains. Taken together, we identify SPTAN1 as a novel prognostic biomarker in CRC and show that SPTAN1 expression levels may predict patient responses to chemotherapy. These investigations illustrate how an affordable, histology-based diagnostic test could directly impact therapeutic decision-making at the bedside.
Clonal hematopoiesis of indeterminate potential (CHIP) is caused by recurrent somatic mutations leading to clonal blood cell expansion. However, direct evidence of the fitness of CHIP-mutated human hematopoietic stem cells (HSCs) in blood reconstitution is lacking. Because myeloablative treatment and transplantation enforce stress on HSCs, we followed 81 patients with solid tumors or lymphoid diseases undergoing autologous stem cell transplantation (ASCT) for the development of CHIP. We found a high incidence of CHIP (22%) after ASCT with a high mean variant allele frequency (VAF) of 10.7%. Most mutations were already present in the graft, albeit at lower VAFs, demonstrating a selective reconstitution advantage of mutated HSCs after ASCT. However, patients with CHIP mutations in DNA-damage response genes showed delayed neutrophil reconstitution. Thus, CHIP-mutated stem and progenitor cells largely gain on clone size upon ASCT-related blood reconstitution, leading to an increased future risk of CHIP-associated complications.
Six p53 wild-type cancer cell lines from infrequently p53-mutated entities (neuroblastoma, rhabdomyosarcoma, and melanoma) were continuously exposed to increasing concentrations of the murine double minute 2 inhibitor nutlin-3, resulting in the emergence of nutlin-3-resistant, p53-mutated sublines displaying a multi-drug resistance phenotype. Only 2 out of 28 sublines adapted to various cytotoxic drugs harboured p53 mutations. Nutlin-3-adapted UKF-NB-3 cells (UKF-NB-3rNutlin10 μM, harbouring a G245C mutation) were also radiation resistant. Analysis of UKF-NB-3 and UKF-NB-3rNutlin10 μM cells by RNA interference experiments and lentiviral transduction of wild-type p53 into p53-mutated UKF-NB-3rNutlin10 μM cells revealed that the loss of p53 function contributes to the multi-drug resistance of UKF-NB-3rNutlin10 μM cells. Bioinformatics PANTHER pathway analysis based on microarray measurements of mRNA abundance indicated a substantial overlap in the signalling pathways differentially regulated between UKF-NB-3rNutlin10 μM and UKF-NB-3 and between UKF-NB-3 and its cisplatin-, doxorubicin-, or vincristine-resistant sublines. Repeated nutlin-3 adaptation of neuroblastoma cells resulted in sublines harbouring various p53 mutations with high frequency. A p53 wild-type single cell-derived UKF-NB-3 clone was adapted to nutlin-3 in independent experiments. Eight out of ten resulting sublines were p53-mutated harbouring six different p53 mutations. This indicates that nutlin-3 induces de novo p53 mutations not initially present in the original cell population. Therefore, nutlin-3-treated cancer patients should be carefully monitored for the emergence of p53-mutated, multi-drug-resistant cells.
This study presents comprehensive real-world data on the use of anti-human epidermal growth factor receptor 2 (HER2) therapies in patients with HER2-positive metastatic breast cancer (MBC). Specifically, it describes therapy patterns with trastuzumab (H), pertuzumab + trastuzumab (PH), lapatinib (L), and trastuzumab emtansine (T-DM1). The PRAEGNANT study is a real-time, real-world registry for MBC patients. All therapy lines are documented. This analysis describes the utilization of anti-HER2 therapies as well as therapy sequences. Among 1936 patients in PRAEGNANT, 451 were HER2-positive (23.3%). In the analysis set (417 patients), 53% of whom were included in PRAEGNANT in the first-line setting, 241 were treated with H, 237 with PH, 85 with L, and 125 with T-DM1 during the course of their therapies. The sequence PH → T-DM1 was administered in 51 patients. Higher Eastern Cooperative Oncology Group (ECOG) scores, negative hormone receptor status, and visceral or brain metastases were associated with more frequent use of this therapy sequence. Most patients received T-DM1 after treatment with pertuzumab. Both novel therapies (PH and T-DM1) are utilized in a high proportion of HER2-positive breast cancer patients. As most patients receive T-DM1 after PH, real-world data may help to clarify whether the efficacy of this sequence is similar to that in the approval study.
Intrahepatic cholangiocarcinoma (iCCA) is the most frequent subtype of cholangiocarcinoma (CCA), and the incidence has globally increased in recent years. In contrast to surgically treated iCCA, data on the impact of fibrosis on survival in patients undergoing palliative chemotherapy are missing. We retrospectively analyzed the cases of 70 patients diagnosed with iCCA between 2007 and 2020 in our tertiary hospital. Histopathological assessment of fibrosis was performed by an expert hepatobiliary pathologist. Additionally, the fibrosis-4 score (FIB-4) was calculated as a non-invasive surrogate marker for liver fibrosis. For overall survival (OS) and progression-free survival (PFS), Kaplan–Meier curves and Cox-regression analyses were performed. Subgroup analyses revealed a median OS of 21 months (95% CI = 16.7–25.2 months) and 16 months (95% CI = 7.6–24.4 months) for low and high fibrosis, respectively (p = 0.152). In non-cirrhotic patients, the median OS was 21.8 months (95% CI = 17.1–26.4 months), compared with 9.5 months (95% CI = 4.6–14.3 months) in cirrhotic patients (p = 0.007). In conclusion, patients with iCCA and cirrhosis receiving palliative chemotherapy have decreased OS rates, while fibrosis has no significant impact on OS or PFS. These patients should not be prevented from state-of-the-art first-line chemotherapy.
Background: No North-American study tested the survival benefit of chemotherapy in de novo metastatic prostate cancer according to race/ethnicity. We addressed this void.
Methods: We identified de novo metastatic prostate cancer patients within the Surveillance, Epidemiology, and End Results database (2014–2015). Separate and specific Kaplan–Meier plots and Cox regression models tested for overall survival differences between chemotherapy-exposed versus chemotherapy-naïve patients in four race/ethnicity groups: Caucasian versus African-American versus Hispanic/Latino vs Asian. Race/ethnicity specific propensity score matching was applied. Here, additional landmark analysis was performed.
Results: Of 4232 de novo metastatic prostate cancer patients, 2690 (63.3%) were Caucasian versus 783 (18.5%) African-American versus 504 (11.8%) Hispanic/Latino versus 257 (6.1%) Asian. Chemotherapy rates were: 21.3% versus 20.8% versus 21.0% versus 20.2% for Caucasians versus African-Americans versus Hispanic/Latinos versus Asians, respectively. At 30 months of follow-up, overall survival rates between chemotherapy-exposed versus chemotherapy-naïve patients were 61.5 versus 53.2% (multivariable hazard ratio [mHR]: 0.76, 95 confidence interval [CI]: 0.63–0.92, p = 0.004) in Caucasians, 55.2 versus 51.6% (mHR: 0.76, 95 CI: 0.54–1.07, p = 0.11) in African-Americans, 62.8 versus 57.0% (mHR: 1.11, 95 CI: 0.73–1.71, p = 0.61) in Hispanic/Latinos and 77.7 versus 65.0% (mHR: 0.31, 95 CI: 0.11–0.89, p = 0.03) in Asians. Virtually the same findings were recorded after propensity score matching within each race/ethnicity group.
Conclusions: Caucasian and Asian de novo metastatic prostate cancer patients exhibit the greatest overall survival benefit from chemotherapy exposure. Conversely, no overall survival benefit from chemotherapy exposure could be identified in either African-Americans or Hispanic/Latinos. Further studies are clearly needed to address these race/ethnicity specific disparities.
Introduction: Over the last decade, multiple clinical trials demonstrated improved survival after chemotherapy for metastatic prostate cancer (mPCa). However, real-world data validating this effect within large-scale epidemiological data sets are scarce. We addressed this void. Materials and Methods: Men with de novo mPCa were identified and systemic chemotherapy status was ascertained within the Surveillance, Epidemiology, and End Results database (2004–2016). Patients were divided between historical (2004–2013) versus contemporary (2014–2016). Chemotherapy rates were plotted over time. Kaplan–Meier plots and Cox regression models with additional multivariable adjustments addressed overall and cancer-specific mortality. All tests were repeated in propensity-matched analyses. Results: Overall, 19,913 patients had de novo mPCa between 2004 and 2016. Of those, 1838 patients received chemotherapy. Of 1838 chemotherapy-exposed patients, 903 were historical, whereas 905 were contemporary. Chemotherapy rates increased from 5% to 25% over time. Median overall survival was not reached in contemporary patients versus was 24 months in historical patients (hazard ratio [HR]: 0.55, p < 0.001). After propensity score matching and additional multivariable adjustment (age, prostate-specific antigen, GGG, cT-stage, cN-stage, cM-stage, and local treatment) a HR of 0.55 (p < 0.001) was recorded. Analyses were repeated for cancer-specific mortality after adjustment for other cause mortality in competing risks regression models and recorded virtually the same findings before and after propensity score matching (HR: 0.55, p < 0.001). Conclusions: In mPCa patients, chemotherapy rates increased over time. A concomitant increase in survival was also recorded.
Effect of chemotherapy on overall survival in contemporary metastatic prostate cancer patients
(2021)
Introduction: Randomized clinical trials demonstrated improved overall survival in chemotherapy exposed metastatic prostate cancer patients. However, real-world data validating this effect with large scale epidemiological data sets are scarce and might not agree with trials. We tested this hypothesis.
Materials and Methods: We identified de novo metastatic prostate cancer patients within the Surveillance, Epidemiology, and End Results (SEER) database (2014-2015). Kaplan-Meier plots and Cox regression models tested for overall survival differences between chemotherapy-exposed patients vs chemotherapy-naïve patients. All analyses were repeated in propensity-score matched cohorts. Additionally, landmark analyses were applied to account for potential immortal time bias.
Results: Overall, 4295 de novo metastatic prostate cancer patients were identified. Of those, 905 (21.1%) patients received chemotherapy vs 3390 (78.9%) did not. Median overall survival was not reached at 30 months follow-up. Chemotherapy-exposed patients exhibited significantly better overall survival (61.6 vs 54.3%, multivariable HR:0.82, CI: 0.72-0.96, p=0.01) at 30 months compared to their chemotherapy-naïve counterparts. These findings were confirmed in propensity score matched analyses (multivariable HR: 0.77, CI:0.66-0.90, p<0.001). Results remained unchanged after landmark analyses were applied in propensity score matched population.
Conclusions: In this contemporary real-world population-based cohort, chemotherapy for metastatic prostate cancer patients was associated with better overall survival. However, the magnitude of overall survival benefit was not comparable to phase 3 trials.
Medulloblastoma is a rare brain malignancy. Patients after puberty are rare and bear an intermediate prognosis. Standard treatment consists of maximal resection plus radio-chemotherapy. Treatment toxicity is high and produces disabling long-term side effects. The sonic hedgehog (SHH) subgroup is highly overrepresented in the post-pubertal and adult population and can be targeted by smoothened (SMO) inhibitors. No practice-changing prospective randomized data have been generated in adults. The EORTC 1634-BTG/NOA-23 trial will randomize patients between standard-dose vs. reduced-dosed craniospinal radiotherapy and SHH-subgroup patients between the SMO inhibitor sonidegib (OdomzoTM, Sun Pharmaceuticals Industries, Inc., New York, USA) in addition to standard radio-chemotherapy vs. standard radio-chemotherapy alone to improve outcomes in view of decreased radiotherapy-related toxicity and increased efficacy. We will further investigate tumor tissue, blood, and cerebrospinal fluid as well as magnetic resonance imaging and radiotherapy plans to generate information that helps to further improve treatment outcomes. Given that treatment side effects typically occur late, long-term follow-up will monitor classic side effects of therapy, but also health-related quality of life, cognition, social and professional outcome, and reproduction and fertility. In summary, we will generate unprecedented data that will be translated into treatment changes in post-pubertal patients with medulloblastoma and will help to design future clinical trials.
Novel insights into the synergistic interaction of Bortezomib and TRAIL: tBid provides the link
(2011)
The proteasome inhibitor Bortezomib has been identified as a potent enhancer of TRAIL-induced apoptosis in several human cancers. However, the identification of the underlying molecular mechanisms of this synergistic cell death induction has been ongoing over the last years. A recent study identifies a new mechanism of action for the synergism of TRAIL and Bortezomib.
Background: Long-term survival in patients with esophageal cancer remains dismal despite the recent improvements in surgery, the advances in radiotherapy (RT) technology, and the refinement of systemic treatments, including the advent of targeted therapies. Although surgery constitutes the treatment of choice for early-stage disease (stage I), a multimodal approach, including preoperative or definitive chemoradiotherapy (CRT) and perioperative chemotherapy, is commonly pursued in patients with locally advanced disease. Methods: A review of the literature was performed to assess the role of RT, alone or in combination with chemotherapy, in the management of esophageal cancer. Results: Evidence from large, randomized phase III trials and meta-analyses supports the application of perioperative chemotherapy alone or preoperative concurrent CRT in patients with lower esophageal and esophagogastric junction adenocarcinomas. Preoperative CRT but not preoperative chemotherapy alone is now routinely used in patients with locally advanced squamous cell carcinoma (SCC). Additionally, definitive CRT without surgery has also emerged as a valuable approach in the management of resectable esophageal SCC to avoid surgery-related morbidity and mortality, whereas salvage surgery is reserved for those with persistent disease. Furthermore, brachytherapy offers a valuable option in the palliative treatment of patients with locally advanced, unresponsive disease. Fluorodeoxyglucose-positron emission tomography (FDG-PET) can facilitate a more accurate treatment response assessment and patient selection. Finally, the development of modern RT techniques, such as intensity-modulated and image-guided RT as well as FDG-PET-based RT planning, could further increase the therapeutic ratio of CRT. Conclusion: Altogether, CRT constitutes an important tool in the treatment armamentarium for esophageal cancer. Further optimization of CRT using modern technology and imaging, targeted therapies, and newer chemotherapeutic agents is a major challenge and should be the goal of future research and clinical trials.
Hematotoxicity is one of the major side effects of chemotherapy. The aim of this study was to examine the association between single nucleotide polymorphisms (SNPs) and hematotoxicity in breast cancer patients in a subset of patients of the SUCCESS prospective phase III chemotherapy study. All patients (n = 1678) received three cycles of 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) followed by three cycles of docetaxel or docetaxel/gemcitabine, depending on randomization. Germline DNA was genotyped for 246 SNPs selected from a previous genome-wide association study (GWAS) in a panel of lymphoblastoid cell lines, with gemcitabine toxicity as the phenotype. All SNPs were tested for their value in predicting grade 3 or 4 neutropenic or leukopenic events (NLEs). Their prognostic value in relation to overall survival and disease-free survival was also tested.
None of the SNPs was found to be predictive for NLEs during treatment with docetaxel/gemcitabine. Two SNPs in and close to the PIGB gene significantly improved the prediction of NLEs after FEC, in addition to the factors of age and body surface area. The top SNP (rs12050587) had an odds ratio of 1.38 per minor allele (95% confidence interval, 1.17 to 1.62). No associations were identified for predicting disease-free or overall survival.
Genetic variance in the PIGB gene may play a role in determining interindividual differences in relation to hematotoxicity after FEC chemotherapy.
Clonal hematopoiesis of indeterminate potential (CHIP) is caused by recurrent somatic mutations leading to clonal blood cell expansion. However, direct evidence of the fitness of CHIP-mutated human hematopoietic stem cells (HSCs) in blood reconstitution is lacking. Because myeloablative treatment and transplantation enforce stress on HSCs, we followed 81 patients with solid tumors or lymphoid diseases undergoing autologous stem cell transplantation (ASCT) for the development of CHIP. We found a high incidence of CHIP (22%) after ASCT with a high mean variant allele frequency (VAF) of 10.7%. Most mutations were already present in the graft, albeit at lower VAFs, demonstrating a selective reconstitution advantage of mutated HSCs after ASCT. Thus, CHIP-mutated stem and progenitor cells largely gain on clone size upon ASCT-related blood reconstitution, leading to an increased future risk of CHIP-associated complications. CHIP increase with age and is also associated with atherosclerosis and inflammation. Age and inflammation are the major risk factors for heart failure, yet the association of CHIP with chronic ischemic heart failure (CHF) in humans is unknown. Therefore, we analyzed bone marrow-derived mononuclear cells from 200 patients with CHF by NGS to detect the presence of CHIP and associated such with long-term prognosis in patients with CHF. Forty-seven mutations with a VAF of at least 2% were found in 18.5% of 200 patients with CHF. The mutations most commonly occurred in the genes DNMT3A and TET2. During a median follow-up of 4.4 years, a significantly worse clinical outcome for patients with either DNMT3A or TET2 mutations compared with non-CHIP carriers was notable. Importantly, there was a significant dose-response association between VAF and clinical outcome. Our data suggest that somatic mutations in hematopoietic cells, may be significantly associated with the progression and poor prognosis of CHF.
Chemotherapy and diffuse low-grade gliomas : a survey within the European Low-Grade Glioma Network
(2018)
Background: Diffuse low-grade gliomas (DLGGs) are rare and incurable tumors. Whereas maximal safe, functional-based surgical resection is the first-line treatment, the timing and choice of further treatments (chemotherapy, radiation therapy, or combined treatments) remain controversial.
Methods: An online survey on the management of DLGG patients was sent to 28 expert centers from the European Low-Grade Glioma Network (ELGGN) in May 2015. It contained 40 specific questions addressing the modalities of use of chemotherapy in these patients.
Results: The survey demonstrated a significant heterogeneity in practice regarding the initial management of DLGG patients and the use of chemotherapy. Interestingly, radiation therapy combined with the procarbazine, CCNU (lomustine), and vincristine regimen has not imposed itself as the gold-standard treatment after surgery, despite the results of the Radiation Therapy Oncology Group 9802 study. Temozolomide is largely used as first-line treatment after surgical resection for high-risk DLGG patients, or at progression.
Conclusions: The heterogeneity in the management of patients with DLGG demonstrates that many questions regarding the postoperative strategy and the use of chemotherapy remain unanswered. Our survey reveals a high recruitment potential within the ELGGN for retrospective or prospective studies to generate new data regarding these issues.
Bloodstream infections (BSI) are a severe complication of antineoplastic chemotherapy or hematopoietic stem cell transplantation (HSCT), especially in the presence of antibiotic resistance (AR). A multinational, multicenter retrospective study in patients aged ≤ 18 years, treated with chemotherapy or HSCT from 2015 to 2017 was implemented to analyze AR among non-common skin commensals BSI. Risk factors associated with AR, intensive care unit (ICU) admission and mortality were analyzed by multilevel mixed effects or standard logistic regressions. A total of 1291 BSIs with 1379 strains were reported in 1031 patients. Among Gram-negatives more than 20% were resistant to ceftazidime, cefepime, piperacillin-tazobactam and ciprofloxacin while 9% was resistant to meropenem. Methicillin-resistance was observed in 17% of S. aureus and vancomycin resistance in 40% of E. faecium. Previous exposure to antibiotics, especially to carbapenems, was significantly associated with resistant Gram-negative BSI while previous colonization with methicillin-resistant S. aureus was associated with BSI due to this pathogen. Hematological malignancies, neutropenia and Gram-negatives resistant to >3 antibiotics were significantly associated with higher risk of ICU admission. Underlying disease in relapse/progression, previous exposure to antibiotics, and need of ICU admission were significantly associated with mortality. Center-level variation showed a greater impact on AR, while patient-level variation had more effect on ICU admission and mortality. Previous exposure to antibiotics or colonization by resistant pathogens can be the cause of AR BSI. Resistant Gram-negatives are significantly associated with ICU admission and mortality, with a significant role for the treating center too. The significant evidence of center-level variations on AR, ICU admission and mortality, stress the need for careful local antibiotic stewardship and infection control programs.
Objectives: To describe changes in costs of managing hospitalised patients with acute myeloid leukaemia (AML) after chemotherapy in Germany over 3 yr, with a special focus on prophylaxis and treatment patterns as well as resource use related to invasive fungal infections (IFI).
Methods: The study was conducted as a retrospective, single-centre chart review in patients with AML hospitalised for chemotherapy, neutropenia and infections after myelosuppressive chemotherapy from January 2004 to December 2006 in Germany. The following resource utilisation data were collected: inpatient stay, mechanical ventilation, parenteral feeding, diagnostics, systemic antifungal medication and cost-intensive concomitant medication. Direct medical costs were calculated from hospital provider perspective.
Results: A total of 471 episodes in 212 patients were included in the analysis. Occurrence of IFI decreased from 5.9% in 2004 to 1.9% in 2006. Mean (± standard deviation) hospital stay decreased from 28.7 ± 17.9 d in 2004 to 22.4 ± 11.8 d in 2006. From 2004 to 2006, the use of a single antifungal drug increased from 30.4% to 46.9%, whereas the use of multiple antifungal drugs decreased from 24.4% to 13.1%. The use of liposomal amphotericin B declined between 2004 and 2006 (21.4% vs. 3.8%) and caspofungin between 2005 and 2006 (19.3% vs. 8.1%). Total costs per episode declined from €19051 ± 19024 in 2004 to €13531 ± 9260 in 2006; major reductions were observed in the use of antimycotics and blood products as well as length of hospital stay.
Conclusion: Analysis of real-life data from one single centre in Germany demonstrated a change in antifungal management of patients with AML between 2004/2005 and 2006, accompanied by a decline in total costs.
Die Herstellung von Poly(butylcyanoacrylat)-Nanopartikeln (PBCA-NP) ist seit fast 25 Jahren bekannt. Sie erfolgt meist durch anionische Emulsionspolymerisation von Butylcyanoacrylat unter Verwendung von Dextran 70.000 als Stabilisator. Vereinzelt wurde in früheren Arbeiten bereits Pluronic® F68 als Emulgator für die Polymerisationsreaktion verwendet. Diese Arbeit hat ihren Schwerpunkt in der Herstellung von PBCA-NP mit F68 als Stabilisator. Es konnte gezeigt werden, dass sich mit diesem Hilfsstoff ebenfalls nanopartikuläre Trägersysteme reproduzierbar und im gewünschten Größenbereich um 200 nm herstellen lassen. Diese Partikel besitzen im Gegensatz zu Dextran-stabilisierten NP eine sehr enge Größenverteilung. Im Rahmen dieser Arbeit wurden die hergestellten NP im Bezug auf ihr Molekulargewicht und ihre Dichte charakterisiert. Ein Partikel besitzt die Masse von ca. 2,5 * 109 Dalton und hat eine Dichte von etwa 1,148 g/cm³. Bei einem PBCA-Nanopartikel handelt es sich jedoch nicht um ein Riesenmolekül, vielmehr wird er durch Agglomeration von relativ kurzen Polymerketten gebildet. Ein Partikel besteht aus ca. einer Million Polymerketten, welche ein Molekulargewicht von ca. 2500 g/mol besitzen. Der Einfluss der Herstellungsparameter auf leere und arzneistoffbeladene Partikel wurde untersucht. Die Partikel wurden hierbei durch die Parameter Partikelgröße, Polydispersität, Partikelausbeute, Zetapotential und Molekulargewicht charakterisiert. Neben der Herstellung durch anionische Emulsionspolymerisation wurden NP durch radikalische Emulsionspolymerisation und Nanopräzipitation erhalten. Auch unter Verwendung dieser Verfahren wurden Trägersysteme im gewohnten Größenbereich um 200 nm gebildet. Zusätzlich zur Herstellung von NP hat sich diese Arbeit auch mit den Charakterisierungsmethoden für kleinpartikuläre Arzneiformen auseinandergesetzt. Es konnte gezeigt werden, dass die häufig angewendete dynamische Lichtstreuung ein geeignetes Verfahren zur Ermittlung des mittleren Partikeldurchmessers darstellt. Die Ergebnisse dieser Methode stimmen weitgehend mit den Resultaten der zusätzlich verwendeten mikroskopischen Verfahren und der analytischen Ultrazentrifugation überein. Der Einsatz der analytischen Ultrazentrifugation lieferte die best aufgelöste Partikelgrößenverteilung und ermöglichte darüber hinaus die Bestimmung der Dichte der Partikel. Neben der mittleren Größe der Trägersysteme wurde auch das mittlere Molekulargewicht der gebildeten Polymerketten bestimmt. Die hierfür als Standard eingesetzte Gel-Permeations-Chromatographie wurde mit einem relativ neuen Verfahren, der MALDI TOF Massenspektrometrie verglichen. Beide Verfahren lieferten ein zahlenmittleres Molekulargewicht der Polymerketten von 2500 – 3000 Da. Lediglich im Bezug auf das gewichtsmittlere Molekulargewicht zeigten sich größere Unterschiede zwischen beiden Messverfahren, welche jedoch auf das zugrunde liegende Messprinzip und nicht auf das untersuchte PBCA zurückzuführen sind. Mit Hilfe der Massenspektrometrie konnte die chemische Struktur der Polymerketten näher aufgeklärt werden. Neben den Produkten des seit langem postulierten Reaktionsmechanismus finden sich Derivate des Polymers, welche formal durch Abspaltung bzw. Anlagerung von Formaldehyd entstehen. Die Menge an frei vorliegendem Formaldehyd scheint jedoch so gering zu sein, dass sie kaum die Hauptursache für die relative Toxizität der PACA-NP darstellen kann. Darüber hinaus ist es möglich, durch Wahl der Reaktionsbedingungen die Bildung von Derivaten des Ursprungspolymers und von Formaldehyd zu minimieren. Die Ergebnisse in der Herstellung und Charakterisierung von leeren Pluronic® F68-stabilisierten PBCA-NP ließen die Verwendung von Doxorubicin-beladenen NP unter Verwendung dieses Stabilisators für die Gehirntumor-Therapie viel versprechend erscheinen. Die hergestellten Nanopartikel zeigten eine im Vergleich zu Dextran-stabilisierten Doxorubicin-NP signifikant niedrigere Arzneistoffbeladung. Die dessen ungeachtet durchgeführte experimentelle Chemotherapie an Glioblastom-tragenden Ratten lieferte jedoch ermutigende Ergebnisse. Die neu entwickelte Zubereitung führte zu einem vergleichbaren Prozentsatz an Remissionen wie die bisherige Standard-PBCA-Formulierung. Die F68-stabilisierte Formulierung und die bisherige Standard-Formulierung mit Polysorbat 80 zeigten nach Inkubation mit humanem Plasma ein vergleichbares Adsorptionsmuster an Plasmaproteinen. Auf Basis der vorangegangenen Studien und dieser Arbeit erscheint es möglich, eine potente nanopartikuläre Doxorubicin-Zubereitung zu entwickeln, welche ausreichend charakterisiert ist, um ihre Anwendung am Menschen zu vertreten.