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Dive into the research topics where Martin Janssen is active.

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Featured researches published by Martin Janssen.


BMC Cancer | 2012

Validation of CRP as prognostic marker for renal cell carcinoma in a large series of patients

Sandra Steffens; Astrid Köhler; Raphael Rudolph; Hendrik Eggers; Christoph Seidel; Martin Janssen; Gerd Wegener; Mark Schrader; Markus A. Kuczyk; A.J. Schrader

BackgroundTo evaluate the prognostic significance of the pre-operative C-reactive protein (CRP) serum level in patients with renal cell cancer (RCC).MethodsWe evaluated 1,161 RCC patients with complete patient and tumour specific characteristics as well as information about their pre-operative CRP-level, who had undergone either radical nephrectomy or nephron-sparing surgery at two German high-volume centres (University Hospitals of Hannover and Ulm). The mean follow-up was 54 months.ResultsThe CRP-level, stratified to three subgroups (CRP ≤ 4, 4–10, and >10 mg/l), correlated significantly with tumour stage (p < 0.001), the risk of presenting nodal disease (2.1, 3.1, and 16.4%) and distant metastasis (2.9, 8.6, and 30.0%; p < 0.001). The Kaplan-Meier 5-year cancer specific survival (CSS) rates were 89.4, 77.9, and 49.5%, respectively (p < 0.001). Multivariate analysis identified CRP as an independent prognosticator for CSS as well as overall survival (p < 0.001). Patients with a CRP of 4–10 and >10 mg/l had a 1.67 and 2.48 fold higher risk of dying due to their RCC compared to those with a pre-operative CRP ≤4 mg/l, respectively.ConclusionsA high preoperative serum CRP level is an independent predictor of poor survival in patients with RCC. Its routine use could allow better risk stratification and risk-adjusted follow-up of RCC patients.


European Urology | 2011

Short-Term Functional and Oncologic Outcomes of Nephron-Sparing Surgery for Renal Tumours ≥7 cm

Frank Becker; F. Roos; Martin Janssen; Walburgis Brenner; C. Hampel; S. Siemer; Joachim W. Thüroff; M. Stöckle

BACKGROUND Nephron-sparing surgery (NSS) for renal tumours preserves renal function and has become the standard approach for small renal tumours. Little is known about perioperative and oncologic outcomes of patients following NSS in renal tumours ≥ 7 cm in the presence of a healthy contralateral kidney. OBJECTIVE To analyse oncologic outcomes and perioperative morbidity in patients treated by NSS for renal tumours ≥ 7 cm. DESIGN, SETTING, AND PARTICIPANTS In total, 5767 patients were treated for renal tumours at two institutions from 1984 to 2009. In 91 patients, elective NSS was performed for renal tumours ≥ 7 cm. MEASUREMENTS Complication rates were assessed in detail and stratified using the Clavien-Dindo score (CDS). Oncologic outcomes for overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Logistic regression analysis was used to identify clinical risk factors for complications and prognosticators that have an oncologic impact on OS. RESULTS AND LIMITATIONS The median follow-up was 28 mo (range: 1-247 mo). Twenty-seven patients (29.6%) had perioperative complications and, of these, 89.1% had CDS grade 1 and 2. Twenty-seven percent of the 91 patients had benign lesions. Seven patients (10.6%) died from cancer-related causes. The 5- and 10-yr rates for OS, CSS, and PFS were 88% and 64%, 97% and 83%, and 91% and 78%, respectively. None of the analysed parameters had an impact on morbidity or OS in the univariate analysis. Limitations of this study were its retrospective nature and the relatively short follow-up period for oncologic outcome. CONCLUSIONS NSS for renal tumours ≥ 7 cm can be performed with acceptable complication rates and with oncologic outcomes comparable to radical nephrectomy studies. Our findings support NSS whenever technically feasible to reduce the loss of renal function.


European Journal of Cancer | 2012

Incidence and long-term prognosis of papillary compared to clear cell renal cell carcinoma – A multicentre study

Sandra Steffens; Martin Janssen; Frederik C. Roos; Frank Becker; Simon Schumacher; Christoph Seidel; Gerd Wegener; Joachim W. Thüroff; R. Hofmann; M. Stöckle; S. Siemer; Mark Schrader; Arndt Hartmann; Markus A. Kuczyk; Kerstin Junker; Andres J. Schrader

AIM OF THE STUDY Papillary renal cell carcinoma (pRCC) is the second most common subtype of RCC after the conventional clear cell type (cRCC). However, its characteristics and prognosis have been less intensively investigated. The aim of our study was to examine the tumour characteristics and long-term prognosis of pRCC compared to clear cell RCC (cRCC). METHODS In total, 4941 evaluable patients were subjected to either radical nephrectomy or nephron-sparing surgery for pRCC or cRCC at five centres in Germany (University Hospitals of Hannover, Homburg/Saar, Mainz, Ulm and Marburg) between 1990 and 2010. RESULTS pRCC (n=565) and cRCC (n=4376) patients were comparable with regard to mean age, clinical symptoms, tumour differentiation and regional lymph node metastases. Patients with pRCC had a significantly higher rate of organ confined tumours (pT1-2, N/M0; 74.9% versus 62.9%), less synchronic visceral metastases (9.6% versus 15.2%), and a higher 5-year CSS rate than those with cRCC (85.1% versus 76.9%). Multivariate analysis identified the papillary subtype as a significant positive prognostic factor in localised (HR, 0.45) but as a negative prognostic factor in metastatic tumour stages (HR, 1.37). CONCLUSION pRCC can apparently be differentiated into two subgroups: an organ-confined/localised subgroup with a significantly better prognosis and an advanced/metastatic subgroup with a worse prognosis compared to cRCC.


Kidney International | 2009

Differential kinetics of effector and regulatory T cells in patients on calcineurin inhibitor–based drug regimens

Daniela Presser; Urban Sester; Janine Mohrbach; Martin Janssen; Hans Köhler; Martina Sester

Besides iatrogenic immunosuppression, endogenous suppression by regulatory T cells (Tregs) may also mediate inhibition of effector T cells after transplantation. Here we determined the effect of common immunosuppressive drug regimens on both Treg and effector T cells. Tregs and cytomegalovirus (CMV)-specific T cells were quantified in 88 renal transplant recipients, 58 hemodialysis patients, and 22 controls. T cell dynamics were longitudinally assessed within 20 weeks after transplantation. The number of Tregs was quantified by measurement of CD25 and/or FOXP3-positive cells and by functional assays. CMV-specific T cells were quantified by stimulation-induced intracellular cytokine analysis. Treg frequencies in transplant recipients were significantly lower compared to those in hemodialysis patients and controls. These lower Treg levels were associated with a less pronounced suppression of effector function. Treg levels decreased within the first weeks after transplantation and remained low in the long term. In contrast, although decreased at early post-transplant, long-term levels of CMV-specific T cells normalized to levels found in hemodialysis patients and controls. These studies suggest that there is an initial decrease of Tregs and effector T cells as a consequence of a direct inhibitory effect of immunosuppressive drugs. In the long term, persistently low Treg levels may favor normalization of effector T cells to ensure sufficient pathogen control.


European Journal of Cancer | 2014

Small renal cell carcinomas - How dangerous are they really? Results of a large multicenter study

Sandra Steffens; Kerstin Junker; Frederik C. Roos; Martin Janssen; Frank Becker; Daniela Henn; Gerd Wegener; S. Siemer; R. Hofmann; Mark Schrader; M. Stöckle; Joachim W. Thüroff; Arndt Hartmann; Markus A. Kuczyk; Andres J. Schrader

AIM OF THE STUDY Modern diagnostic ultrasound and cross-sectional imaging has enabled the detection of increasing numbers of renal tumours. The aim of this study was to investigate the tumour- and patient-specific characteristics and prognosis of small renal cell carcinomas (RCCs) after surgical resection. METHODS The study included 2197 patients who underwent surgical resection of histologically confirmed RCC ⩽ 4 cm between 1990 and 2011. Median (mean) follow-up was 56.2 (65.5) months. RESULTS At the time of surgery, tumours were staged as pT ⩾ 3a in 175 (8.0%) cases, 134 (6.2%) were poorly differentiated and 75 (3.5%) were metastasised. The larger the tumour size, the higher was the risk of presenting with stage pT ⩾ 3a (p<0.001), poor tumour differentiation (p = 0.004), microscopic vascular involvement (p = 0.001) and collecting system invasion (p = 0.03). The 5-year cancer-specific survival (CSS) rate was 93.8% for stage pT1a versus 79.4% for stage pT ⩾ 3a (p<0.001), and it was 93.7% for G1-2 versus 76.8% for G3-4 differentiation (p<0.001). Multivariate analysis identified age in years (hazard ratio (HR) 1.04, p<0.001), metastatic disease (HR 12.5, p < 0.001), tumour differentiation (HR 2.8, p<0.001) and non-clear cell histology (HR 0.51, p = 0.02) as independent prognosticators for CSS in patients with small RCC. Interestingly, the 5-year cancer-specific mortality rate for pT1a N/M0 patients was 5.8%. CONCLUSIONS This large multicenter study has clearly shown that, though most small RCC have a low pathological stage and a good prognosis, there is also a small but significant subgroup of these tumours that are already locally advanced or poorly differentiated.


Urologia Internationalis | 2016

da Vinci and Open Radical Prostatectomy: Comparison of Clinical Outcomes and Analysis of Insurance Costs

Christina Niklas; Matthias Saar; Britta Berg; Katrin Steiner; Martin Janssen; S. Siemer; M. Stöckle; Carsten-Henning Ohlmann

Purpose: To assess clinical outcomes and reimbursement costs of open and robotic-assisted radical prostatectomies in Germany. Methods: Perioperative data of 499 open (2003-2006) and 932 (2008-2010) robotic-assisted radical prostatectomies as well as longitudinal reimbursement costs of an anonymized health insurance research database from Germany containing data of patients who underwent robotic-assisted or open radical prostatectomy were retrospectively analysed in a single-centre study. Results: Significantly better outcomes after robotic-assisted vs. open prostatectomy were observed in regards to positive surgical margins (13.3 vs. 22.4%; p < 0.0001), intraoperative transfusions (0.1 vs. 2.6%; p < 0.0001), hospitalization (8.7 vs. 15.2 days; p < 0.0001) and duration of catheter (6.6 vs. 12.8 days; p < 0.0001). Operating time was significantly longer with robotic-assisted radical prostatectomy when compared to open surgery (184.4 vs. 128.0 min; p < 0.0001), while intraoperative complications showed a similar occurrence between both groups. Significant fewer postoperative complications were observed after robotic-assisted radical prostatectomy (26.5 vs. 42.5%; p < 0.0001) and rate of re-admission was lower for the robotic patients (13.6 vs. 19.4%; p = 0.0050). While insurance costs were higher in the 2 years before radical prostatectomy for the patients who underwent a robotic procedure (4,241.60 vs. 3,410.23 €; p = 0.202), additive costs of care of the year of surgery plus the 2 following years were less for the robotic cohort when compared to the costs incurred by the open group (21,673.71 vs. 24,512.37 €; p = 0.1676). Conclusions: The observed clinical advantages of robotic-assisted radical prostatectomy seem to result in reduced health insurance cost postoperatively when compared to open surgery. This should be taken into consideration regarding reimbursement and implementation of a clinically superior method.


PLOS ONE | 2013

Antigen-Specific CD4 T Cells Are Induced after Intravesical BCG-Instillation Therapy in Patients with Bladder Cancer and Show Similar Cytokine Profiles as in Active Tuberculosis

Julia Elsäßer; Martin Janssen; Frank Becker; Henrik Suttmann; Kai-Uwe Schmitt; Urban Sester; M. Stöckle; Martina Sester

Specific T cell immunity in patients with active tuberculosis is associated with a decrease in multifunctionality. However, it is unknown whether cytokine profiles differ in patients with primary infection and those with prior contact. We therefore used intravesical immunotherapy with attenuated live Bacille Calmette–Guérin (BCG) in patients with urothelial carcinoma as a model to characterise the induction of systemic immunity towards purified protein derivate (PPD) and to study whether cytokine profiles differ depending on pre-existing immunity. Eighteen patients with non-muscle invasive bladder cancer were recruited during the BCG-induction course. Fifty-four healthy individuals served as controls. Interferon (IFN)-γ and interleukin (IL)-2 producing PPD-specific CD4 T cells were analysed longitudinally before each instillation using a rapid flow-cytometric whole blood immunoassay. Baseline levels of IFN-γ producing PPD-specific T cells were comparable to controls. T cells showed a 5-fold increase to 0.23% by week 2/3, and further increased 8-fold by week 4/5 (to 0.42%, p=0.0007). Systemic immunity was induced in all patients, although the increase was less pronounced in patients with pre-existing immunity. As in active TB, cytokine profiling during therapy revealed a lower percentage of multifunctional IFN-γ/IL-2 double-positive T cells compared to controls (60.2% vs. 71.9%, p=0.0003). Of note, when comparing patients with and without pre-existing immunity, cytokine profiles in patients with primary immunity were shifted towards IL-2 single producing T cells (p=0.02), whereas those in patients with pre-existing immunity were shifted towards IFN-γ single-positivity (p=0.01). In conclusion, systemic T cell responses were induced after BCG-therapy, and their kinetics and cytokine profile depended on pre-existing immunity. Decreased functionality is a typical feature of specific immunity in both patients with active tuberculosis and BCG-therapy. Among patients with active infection, a shift towards IL-2 or IFN-γ single-positive cells may allow distinction between patients with primary infection and cases with boosted immunity after prior contact, respectively.


European Urology | 2018

Robot-assisted Kidney Transplantation: The European Experience

A. Breda; A. Territo; Luis Gausa; V. Tugcu; Antonio Alcaraz; M. Musquera; Karel Decaestecker; Liesbeth Desender; M. Stöckle; Martin Janssen; Paolo Fornara; Nasreldin Mohammed; Giampaolo Siena; Sergio Serni; Luis Guirado; Carma Facundo; N. Doumerc

BACKGROUND Robot-assisted kidney transplantation (RAKT) has recently been introduced to reduce the morbidity of open kidney transplantation (KT). OBJECTIVE To evaluate perioperative and early postoperative RAKT outcomes. DESIGN, SETTING AND PARTICIPANTS This was a multicenter prospective observational study of 120 patients who underwent RAKT, predominantly with a living donor kidney, in eight European institutions between July 2015 and May 2017, with minimum follow-up of 1 mo. The robot-assisted surgical steps were transperitoneal dissection of the external iliac vessels, venous/arterial anastomosis, graft retroperitonealization, and ureterovesical anastomosis. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Descriptive analysis of surgical data and their correlations with functional outcomes. RESULTS AND LIMITATIONS The median operative and vascular suture time was 250 and 38min, respectively. The median estimated blood loss was 150ml. No major intraoperative complications occurred, although two patients needed open conversion. The median postoperative estimated glomerular filtration rate was 21.2, 45.0, 52.6, and 58.0ml/min on postoperative day 1, 3, 7, and 30, respectively. Both early and late graft function were not related to overall operating time or rewarming time. Five cases of delayed graft function (4.2%) were reported. One case (0.8%) of wound infection, three cases (2.5%) of ileus, and four cases of bleeding (3.3%; three of which required blood transfusion), managed conservatively, were observed. One case (0.8%) of deep venous thrombosis, one case (0.8%) of lymphocele, and three cases (2.5%) of transplantectomy due to massive arterial thrombosis were recorded. In five cases (4.2%), surgical exploration was performed for intraperitoneal hematoma. Limitations of the study include selection bias, the lack of an open control group, and failure to report on patient cosmetic satisfaction. CONCLUSIONS When performed by surgeons with robotic and KT experience, RAKT is safe and reproducible in selected cases and yields excellent graft function. PATIENT SUMMARY We present the largest reported series on robot-assisted kidney transplantation. Use of a robotic technique can yield low complication rates, rapid recovery, and excellent graft function. Further investigations need to confirm our promising data.


Journal of Clinical Virology | 2010

Successful outcome of kidney transplantation from a HBV-DNA positive donor into recipients with cleared HBV-infection using a pre-emptive therapy approach

Janine Mohrbach; Martin Janssen; Gunnar H. Heine; Barbara Gärtner; Danilo Fliser; Martina Sester; Urban Sester

BACKGROUND Donor-derived transmission of hepatitis B virus (HBV) may cause serious complications after transplantation. To date, transplantation from HBV-infected donors to HBV-infected recipients seems feasible, although this is recommended with prophylaxis with specific drugs and antibodies only, whereas pre-emptive strategies are rarely used. OBJECTIVES Here, we assessed the success of transplantation of kidneys from a chronically HBV-infected deceased donor (HBs-antigen positive, anti-HBc positive, HBV-DNA positive) to two recipients with cleared HBV-infection (HBs-antigen negative, anti-HBc positive, anti-HBs >100 IU/l) where risk-assessment was performed using a pre-emptive approach in the absence of prophylaxis. STUDY DESIGN Pre-emptive monitoring included assessment for evidence of infection by analysis of liver enzymes, viral load, and humoral and cellular immunity against HBV and CMV. RESULTS In line with undetectable HBV-load, HBc-specific T-cell frequencies remained stable (mean 0.46+/-0.10% and 0.06+/-0.03%), whereas CMV-specific T-cell frequencies in one patient showed dynamic changes that coincided with CMV-viremia. Likewise, HBV-specific antibody titres were stable. Liver enzymes demonstrated absence of liver-cell injury and renal function was good (creatinine 1.8 and 0.8 mg/dl at last follow-up after 39 and 38 months, respectively). CONCLUSIONS When combined with careful HBV-monitoring, kidneys from HBV-infected donors may be transplanted into HBV-immune recipients without the need for specific prophylaxis.


Human Pathology | 2014

The Fuhrman grading system has no prognostic value in patients with nonsarcomatoid chromophobe renal cell carcinoma

Sandra Steffens; Martin Janssen; Frederik C. Roos; Frank Becker; Julie Steinestel; Mahmoud Abbas; Konrad Steinestel; Gerd Wegener; S. Siemer; Joachim W. Thüroff; R. Hofmann; M. Stöckle; Mark Schrader; Arndt Hartmann; Andrea Hasenfus; Markus A. Kuczyk; Kerstin Junker; Andres J. Schrader

The prognostic value of the Fuhrman nuclear grading system has been questioned for chromophobe renal cell carcinoma (chRCC) because this subtype frequently displays nuclear and nucleolar pleomorphism. The present study reevaluates this grading system in a series of patients with nonsarcomatoid chRCC. We identified 176 patients (3.6%) with nonsarcomatoid chRCC in a total of 4897 patients who underwent surgery for renal cell carcinoma at 5 centers in Germany between 1990 and 2010. The mean follow-up was 51.1 months. The 3 groups (G1 versus G2 versus G3/4) were comparable in terms of age, sex, tumor diameter, and lymph node metastasis. They only differed significantly in tumor stage (P = .01) and the incidence of synchronous visceral metastasis (P = .04). The 5-year cancer-specific survival rates were 84.4% for G1 (n = 32), 84.3% for G2 (n = 108), and 74.1% for G3/4 tumors (n = 33) (P = .58). Accordingly, multivariate analysis including age, sex, tumor stage, and metastatic disease did not identify Fuhrman grading as an independent predictor of cancer-specific survival in patients with chRCC (P = .4). We were able to demonstrate in a large multicenter cohort that the Fuhrman grading system does not qualify as a prognostic tool in patients with chRCC.

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Arndt Hartmann

University of Erlangen-Nuremberg

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