Biomedical subjects

Andres Jan Schrader

Publications and source records attributed to Andres Jan Schrader.

8 recordsLinked to original sources

PubMed2006

Biochemical markers of bone turnover in patients with localized and metastasized prostate cancer.

OBJECTIVE: To evaluate and compare the value of several markers of bone turnover in different stages of prostate cancer, as bone metastases are a common feature in this disease, and for assessing bone metastases both bone formation and bone resorption markers are diagnostic. PATIENTS AND METHODS: The prospective study included 219 men, i.e. 129 undergoing radical retropubic prostatectomy (RRP) and 25 with bone metastases due to prostate cancer, and 65 with benign urological disorders who served as controls. Before any treatment the concentrations of alkaline phosphatase (ALP), osteocalcin, serum C-terminal telopeptide of type I collagen (S-CTX) and tartrate-resistant acid phosphatase type 5b (TRACP5b) were determined. RESULTS: Men undergoing RRP were divided into those with lymph node-negative, localized (pT3, 101) and lymph node-positive (28) disease, after histological examination. The controls had the lowest marker levels while patients with bone metastases due to prostate cancer had the highest levels, with significance for ALP, osteocalcin and TRACP5b. Patients with lymph node-positive cancer had significantly high serum levels of TRACP5b and ALP but not for osteocalcin and S-CTX. CONCLUSIONS: Bone turnover markers represent a new diagnostic tool in prostate cancer; the present data show that both bone resorption and bone formation are crucial for detecting bone metastases in prostate cancer. The value of bone turnover markers in high-risk patients should be evaluated in a longitudinal study.

Adult↗

PubMed2006

Impact of evidence-based interdisciplinary guidelines on testis cancer management.

BACKGROUND: In 1999, interdisciplinary evidence-based guidelines were elaborated for treatment of germ cell tumors in Germany. The aims of the current study were to analyze failures in diagnosis and therapy and to demonstrate the influence of guidelines on individual therapeutic approaches and clinical outcome. Therefore, patient collectives treated before the introduction of guidelines (Group A, 1990-1999, n = 234) and those thereafter (Group B, 2000-2002, n = 84) were compared for recurrence and survival. METHODS: In both groups, medical and/or surgical treatment and clinical outcome were evaluated for therapeutic mistakes and violations of guidelines. These were analyzed for their clinical consequences. RESULTS: There was no significant difference between groups concerning median age of patients or clinical stage before therapy. Altogether, 27.8% and 8.3% of all patients in Group A and B, respectively, displayed therapeutic mistakes (P < 0.005); 63% of these patients in Group A and 100% of these patients in Group B received an overtreatment. In Group A, 19/234 (8.1%) patients relapsed and 53% of these patients had been treated insufficiently (P < 0.005). Advanced disease caused the death of 3/234 patients in this study. As of this writing, only 3 of 84 (3.6%) patients in Group B have relapsed, and no patient has died because of tumor or consecutive treatment. CONCLUSIONS: The integration of interdisciplinary evidence-based guidelines for treatment of testicular germ cell tumors has led to significant reduction of both overtreatment and treatment failure and/or relapse that were due to inappropriate primary therapy. Evidence-based guidelines should serve as internal quality controls in all institutions treating patients with testicular germ cell tumors.

Adolescent↗

PubMed2006

Clinical significance of a prostate-specific antigen flare phenomenon in patients with hormone-refractory prostate cancer receiving docetaxel.

Docetaxel has shown promise for the treatment of hormone-refractory prostate cancer and has become the standard of care. The flare phenomenon is a known entity in androgen-deprivation therapy of advanced prostate cancer and it has also been described in palliative chemotherapy of hormone-refractory prostate cancer. The aim of this study was to evaluate the clinical impact of a prostate-specific antigen flare phenomenon in docetaxel-treated hormone-refractory prostate cancer patients. From December 2002 to August 2005, we treated 44 patients with hormone-refractory prostate cancer applying docetaxel-based regimens. Prostate-specific antigen levels were determined before therapy and weekly thereafter. Patients were divided into three groups: response (group 1), progression (group 2) and flare (group 3). Flare was defined as initially rising prostate-specific antigen under therapy, dropping thereafter to values below baseline. The groups were compared for overall survival by Kaplan-Meier analysis. We observed a prostate-specific antigen flare phenomenon in eight (18%) of 44 evaluable patients; 24 (54.5%) patients were primary responders and 12 (27.3%) experienced progressive disease. In group 3, prostate-specific antigen levels rose to 107-180% from baseline and then dropped to 21-68%. Kaplan-Meier analysis showed significantly better overall median survival for groups 1 (18 months, P=0.0005) and 3 (19 months, P=0.006) than for group 2 (7 months). Survival in groups 1 and 3 was comparable. Grade 3 and 4 toxicity was below 5% and equally distributed between the 3 groups. In our limited patient cohort, prostate-specific antigen flare phenomenon does not seem to be a clinically relevant issue in terms of overall survival. Thus, an initial rise of prostate-specific antigen under docetaxel therapy in hormone-refractory prostate cancer does not indicate therapeutic failure and should not lead to early withdrawal from therapy in the absence of clinical signs of progression.

Androgens↗

PubMed2006

Laparoscopic peritoneal drainage of symptomatic lymphoceles after pelvic lymph node dissection using methylene blue instillation.

BACKGROUND: Lymphoceles are frequent complications of pelvic lymph node dissection. While small lymphoceles often remain undetected, larger ones can cause complications and require further treatment, e.g. percutaneous tube drainage alone or in combination with sclerotherapy. However, recurrence rates are considerable, and long-lasting drainage may lead to infection, prolonged hospitalization, and as a consequence, increased overall costs. We report the results of a simplified laparoscopic approach to drain lymphoceles after radical prostatectomy plus pelvic lymphadenectomy using methylene blue instillation. METHODS: 13 patients with large symptomatic pelvic/retroperitoneal lymphoceles refractory to percutaneous tube drainage and doxycycline sclerotherapy received a laparoscopic transperitoneal marsupialization following instillation of a sterile diluted methylene blue solution into the drained cavity to refill and mark the lymphocele. RESULTS: All lymphoceles were sterile and ranged in size from 7 x 6 x 4 to 15 x 12 x 6 cm. Clinical symptoms included lower abdominal swelling, tenderness in the iliac fossa, ipsilateral lymphedema, deep venous thrombosis, wound fistula, and hydronephrosis due to ureteral obstruction. After methylene blue instillation, the lymphoceles were easily identified and opened. Median total operative time was 50 (range 25-70) min; blood loss was negligible. There was one complication in the form of a metachronous infection in the operating field and no relapses. Patients were discharged 1-5 (median 3) days after the surgical procedure. CONCLUSIONS: Laparoscopic peritoneal drainage requires greater operative skill than percutaneous approaches. However, the instillation of a methylene blue solution simplifies this procedure as the extent and location of the lymphoceles can be precisely identified during laparoscopy. We recommend early application of laparoscopic peritoneal drainage following methylene blue instillation for patients with sterile lymphoceles after pelvic lymph node dissection in whom temporary percutaneous drainage and sclerotherapy failed to resolve the lymph fluid collection.

Drainage↗

PubMed2005

Expression and functional influence of cellular retinoic acid-binding protein II in renal cell carcinoma.

INTRODUCTION: Retinoic acid (RA) and its derivates possess antiproliferative and tumor-suppressive abilities and are successfully used in the treatment of various malignancies. However, in metastatic renal cell carcinoma (RCC), its application did not meet first expectations. As the exact mechanisms of RA action and especially the role of the cellular retinoic acid-binding proteins (CRABP) still remain unclear, we studied the expression of CRABP-II and its potential influence on RA response in RCC. MATERIALS AND METHODS: We used the real-time RT-PCR methodology to investigate CRABP-II expression in 12 RCC samples and corresponding normal kidney tissue. Moreover, CRABP-II was cloned and overexpressed in CAKI-2 RCC cells. CRABP-II (un)transfected CAKI-2 cells were stimulated with all-trans RA (ATRA) and 9-cis RA, and their antiproliferative effects were evaluated using 3H-thymidine-proliferation assays. RESULTS: Using RPS9 and RPLP0 to normalize its expression, the median tumor/kidney ratio for CRABP-II expression was 0.16 and 0.12, respectively. Using proliferation assays, CRABP-II overexpressing CAKI-2 cells did not exhibit a significant change in RA sensitivity, but appeared to be less sensitive toward RA-stimulation compared to CAKI-2 cells expressing naturally low levels of CRABP-II (maximum difference, 59% at 3 microM ATRA). CONCLUSIONS: We were able to demonstrate a downregulation of CRABP-II expression in primary RCC tumor samples compared to the corresponding normal kidney tissue. However, CRABP-II overexpression in CAKI-2 RCC cells did not significantly influence RA associated antiproliferative actions. Further experiments are necessary to define the exact role of CRABP-II and its downregulation in RCC including its influence and dependence on other molecules involved in RA signalling and metabolism.

Aged↗

PubMed2003

Giant hydronephrosis mimicking progressive malignancy.

BACKGROUND: Cases of giant hydronephroses are rare and usually contain no more than 1-2 litres of fluid in the collecting system. We report a remarkable case of giant hydronephrosis mimicking a progressive malignant abdominal tumour. CASE PRESENTATION: A 78-year-old cachectic woman presented with an enormous abdominal tumour, which, according to the patient, had slowly increased in diameter. Medical history was unremarkable except for a hysterectomy >30 years before. A CT scan revealed a giant cystic tumour filling almost the entire abdominal cavity. It was analysed by two independent radiologists who suspected a tumour originating from the right kidney and additionally a cystic ovarian neoplasm. Subsequently, a diagnostic and therapeutic laparotomy was performed: the tumour presented as a cystic, 35 x 30 x 25 cm expansive structure adhesive to adjacent organs without definite signs of invasive growth. The right renal hilar vessels could finally be identified at its basis. After extirpation another tumourous structure emerged in the pelvis originating from the genital organs and was also resected. The histopathological examination revealed a >15 kg hydronephrotic right kidney, lacking hardly any residual renal cortex parenchyma. The second specimen was identified as an ovary with regressive changes and a large partially calcified cyst. There was no evidence of malignant growth. CONCLUSION: Although both clinical symptoms and the enormous size of the tumour indicated malignant growth, it turned out to be a giant hydronephrosis. Presumably, a chronic obstruction of the distal ureter had caused this extraordinary hydronephrosis. As demonstrated in our case, an accurate diagnosis of giant hydronephrosis remains challenging due to the atrophy of the renal parenchyma associated with chronic obstruction. Therefore, any abdominal cystic mass even in the absence of other evident pathologies should include the differential diagnosis of a possible hydronephrosis. Diagnostic accuracy might be increased by a combination of endourological techniques such as retrograde pyelography and modern imaging modalities.

Aged↗

PubMed2003

Application of real-time reverse transcriptase-polymerase chain reaction in urological oncology.

PURPOSE: During the last decade numerous different reverse transcriptase-polymerase chain reaction (RT-PCR) techniques have been described. However, the lack of highly sensitive, quantitative and reliable methodology has been responsible for its limited use in modern urology. Early semiquantitative RT-PCR techniques often proved not to produce consistent results and have a high failure rate due to complicated working models. In this article we provide a comprehensive and intelligible description of real-time PCR technology, which is a novel quantitative methodology to analyze gene expression. In addition, we report the first preclinical and clinical applications in molecular urology. MATERIALS AND METHODS: The current literature was reviewed in regard to different current real-time RT-PCR protocols and their use in modern urological oncology. RESULTS: Real-time RT-PCR is a reliable, rapid and relatively inexpensive technique that can be easily adapted for standardized preclinical and clinical applications at different centers. Its sensitivity equals at least that of conventional RT-PCR and the option of exact quantification of gene expressions allows proper differentiation among high, low and illegitimate RNA transcription. It eliminates post-PCR processing of PCR products, thereby, increasing throughput and decreasing the chance of carryover contamination. CONCLUSIONS: Although the application of real-time RT-PCR has gained wide acceptance in urological research, its routine clinical use is still in its infancy. However, due to its high sensitivity and exact quantitation real-time RT-PCR may be the method of choice for modern preclinical and clinical studies in the future.

Humans↗

PubMedDate not supplied

Detection of circulating tumor cells in patients with renal cell carcinoma by reverse transcriptase polymerase chain reaction for G250/MNCA-9: results of a prospective trial.

OBJECTIVES: Radical nephrectomy displays the standard procedure for patients with localized renal cell carcinoma. The transperitoneal approach is often favored compared to the retroperitoneal approach because of the early ligation of the renal vessels, thereby tumor cell shedding by manipulation of the tumor is thought to be avoided. The aim of our study was to investigate the influence of the surgical technique on intraoperative tumor cell shedding. Furthermore, we evaluated the clinical course of the patients being operated on with either method in terms of complications, postoperative recovery, and hospital stay. METHODS: A total of 55 consecutive patients with renal tumors suspicious for malignancies were evaluated for this study. Peripheral blood samples were obtained from 44 patients at admission, intraoperatively (before and after kidney removal), and before discharge. Ribonucleic acid was extracted, converted to complementary deoxyribonucleic acid, and reverse transcriptase polymerase chain reaction (RT-PCR) with primers specific for G250/MNCA-9 was performed. Data regarding the clinical course of the patients were analyzed retrospectively by reviewing patient files. RESULTS: The clinical course for patients undergoing retroperitoneal nephrectomy was statistically different compared to the transperitoneal approach group regarding operating time and duration of drains, favoring the retroperitoneal approach group. Evaluation of MNCA-9 RT-PCR revealed no difference according to operative technique, tumor-nodes-metastasis, or clinical tumor stage. Despite this result, we found positive RT-PCR signals for MNCA-9 in patients with transitional cell cancer of the renal pelvis and benign renal lesions. CONCLUSIONS: There is no clinical relevant difference between the transperitoneal and retroperitoneal approaches for radical nephrectomy. Furthermore, the retroperitoneal approach does not bear the risk of intraoperative tumor cell shedding by the handling of the tumor.

Aged↗