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Biomedical subjects

G Bartsch

Publications and source records attributed to G Bartsch.

At least 127 records · Page 7Linked to original sources
PubMed1999

Extracorporeal shock wave lithotripsy versus ureteroscopy for distal ureteral calculi: a prospective randomized study.

PURPOSE: We performed a prospective randomized study to determine appropriate first line treatment for distal ureteral stones. MATERIAL AND METHODS: Between January 1996 and October 1997, 80 patients with distal ureteral stones (40 smaller than 5 mm. and 40 larger than 5 mm.) were randomized and treated with extracorporeal shock wave lithotripsy or ureteroscopy with a 9.5 or 6.5F semirigid ureteroscope. RESULTS: Ureteroscopy was significantly better in terms of operative time, fluoroscopy time and time to achieve a stone-free state. The smaller the stones, the greater the difference between the 2 treatment modalities. CONCLUSIONS: For distal ureteral stones we recommend ureteroscopy as first line treatment.

Adult↗
PubMed1999

Cytogenetic characterization of 22 human renal cell tumors in relation to a histopathological classification.

In this study, cytogenetic and fluorescence in situ hybridization analyses were performed on 22 sporadic, unilateral primary renal cell tumors. The tumors were classified according to cell types, growth patterns, and grades of malignancy. A feeder layer technique was used for the cell culture of 13 clear-cell carcinomas, 4 chromophilic carcinomas, 3 chromophobe carcinomas, 1 oncocytoma, and 1 spindle-shaped pleomorphic carcinoma. Eighty-six percent (19/22) of renal tumors showed clonal abnormalities. The most frequent finding in the 15 male patients was loss of chromosome Y (9/15). In 3/15, it was the only observed aberration. The second most visible aberration was regional loss or entire loss of chromosome 9, which was detected in 36% (8/22) of the cases. Four cases showed loss of chromosome 9 and 4 cases a deletion of the short arm with breakpoints on 9p11 and 9p21. Loss of 3p material was observed in 32% (7/22) of the cases but only in 2/13 patients with clear-cell carcinoma. Gain of chromosome 12 or 12p was observed in 27% (6/22). In 23% (5/22) of the patients, gain of whole or partial chromosomes 2, 5, and 7 was found. Less-frequent findings were loss of chromosomes 8, 14, and 21; gain of chromosome 16; and structural abnormalities of chromosome 1 (each 18%; 4/22). Only some of the karyotypes described as typical for the various renal tumor types were confirmed. In contrast with previous reports, chromosome 3 and 9 aberrations did not allow differentiation between tumor types in our study.

Aged↗
PubMed1999

Molecular mechanisms of the effects of sildenafil (VIAGRA).

The molecular mechanisms of the effects of sildenafil, a specific inhibitor of cyclic guanosine monophosphate (cGMP) phosphodiesterases are briefly reviewed. The second messenger cGMP as well as its molecular targets (with the exception of the photoreceptor signal transduction machinery) have long played an underdog role compared with cyclic adenosine monophosphate and other signalling molecules such as inositoltrisphosphate. The same holds for guanylyl cyclase, which, albeit being the main effector molecule of the gaseous neurotransmitters carbon monoxide and nitric oxide (NO), has received much less attention relative to its activators and their synthases. Stimulation of the arginine --> NO --> cGMP pathway by bypassing NO-synthase is a well-established pharmacological principle in the treatment of cardiovascular disorders. In contrast, local application of NO-donors or oral feeding of excessive amounts of precursor amino acid L-arginine to treat erectile dysfunction were met with variable success or failure. The advent of a new principle, amplification of the NO-signaling cascade by means of target organ selective phosphodiesterase inhibition, has renewed interest in phosphodiesterases and cGMP.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1999

Switch from antagonist to agonist of the androgen receptor bicalutamide is associated with prostate tumour progression in a new model system.

Advanced prostate cancer is treated by androgen ablation and/or androgen receptor (AR) antagonists. In order to investigate the mechanisms relevant to the development of therapy-resistant tumours, we established a new tumour model which closely resembles the situation in patients who receive androgen ablation therapy. Androgen-sensitive LNCaP cells were kept in androgen-depleted medium for 87 passages. The new LNCaP cell subline established in this manner, LNCaP-abl, displayed a hypersensitive biphasic proliferative response to androgen until passage 75. Maximal proliferation of LNCaP-abl cells was achieved at 0.001 nM of the synthetic androgen methyltrienolone (R1881), whereas 0.01 nM of this compound induced the same effect in parental cells. At later passages (> 75), androgen exerted an inhibitory effect on growth of LNCaP-abl cells. The non-steroidal anti-androgen bicalutamide stimulated proliferation of LNCaP-abl cells. AR protein expression in LNCaP-abl cells increased approximately fourfold. The basal AR transcriptional activity was 30-fold higher in LNCaP-abl than in LNCaP cells. R1881 stimulated reporter gene activity in LNCaP-abl cells even at 0.01 nM, whereas 0.1 nM of R1881 was needed for induction of the same level of reporter gene activity in LNCaP cells. Bicalutamide that acts as a pure antagonist in parental LNCaP cells showed agonistic effects on AR transactivation activity in LNCaP-abl cells and was not able to block the effects of androgen in these cells. The non-steroidal AR blocker hydroxyflutamide exerted stimulatory effects on AR activity in both LNCaP and LNCaP-abl cells; however, the induction of reporter gene activity by hydroxyflutamide was 2.4- to 4-fold higher in the LNCaP-abl subline. The changes in AR activity were associated neither with a new alteration in AR cDNA sequence nor with amplification of the AR gene. Growth of LNCaP-abl xenografts in nude mice was stimulated by bicalutamide and repressed by testosterone. In conclusion, our results show for the first time that the nonsteroidal anti-androgen bicalutamide acquires agonistic properties during long-term androgen ablation. These findings may have repercussions on the natural course of prostate cancer with androgen deprivation and on strategies of therapeutic intervention.

Androgen Antagonists↗
PubMed1999

[Assessment of renal resistance index in children with vesico-ureteral reflux].

AIM: To assess the value of the renal resistive index (RI) in evaluating renal perfusion in children with vesicoureteral reflux (VUR). METHOD: We investigated 92 kidneys in 46 children with VUR with a mean age of 6 +/- 4 years. The RI was measured at the level of the interlobar-/arcuate-arteries using a color Doppler unit Acuson 128 XP/10 (Mountain View, Cal.). The results of the RI-measurement were correlated to the findings in renal scintigraphy. RESULTS: Children with VUR grade I-III showed RI-values less than the normal physiological upper limit of 0.7. Patients with VUR grade IV-V demonstrated a significant increased RI-value of 0.77 +/- 0.07 (p < 0.0001). The correlation of the RI-measurements with the scintigraphic findings revealed a correlation-coefficient of r2 = 0.61. CONCLUSION: Changes of renal perfusion were only found in high-grade VUR, demonstrating a good correlation with the scintigraphic findings. Therefore color Doppler ultrasound seems to be helpful in the follow-up of patients with high-grade reflux.

Child↗
PubMed1999

Crossing vessels at the ureteropelvic junction: detection with contrast-enhanced color Doppler imaging.

PURPOSE: To investigate the feasibility of imaging crossing vessels at the ureteropelvic junction (UPJ) preoperatively by means of contrast agent-enhanced color Doppler imaging (CDI). MATERIALS AND METHODS: Twenty-nine patients (13 female patients, 16 male patients; age range, 17-76 years; mean age, 45 years) with symptomatic UPJ obstruction were examined with CDI before and after intravenous infusion of the contrast agent. The type (i.e., arterial or venous) and position of the vessel relative to the UPJ (i.e., anterior or posterior) were assessed. The CDI findings were correlated with the surgical findings at laparoscopic pyeloplasty. RESULTS: Among the 29 patients, crossing vessels were detected with nonenhanced CDI in 15 patients, with enhanced CDI in 22 patients, and with laparoscopy in 23 patients. Enhanced CDI depicted crossing vessels in 22 (96%) of the 23 laparoscopically confirmed cases compared with nonenhanced CDI, which depicted 15 (65%) of the 23 cases. The rate of detecting crossing vessels increased significantly with use of the contrast agent (P < .016, McNemar test). CONCLUSION: Compared with nonenhanced CDI, contrast-enhanced CDI significantly improves the detection of crossing vessels at the UPJ and is useful in the presurgical evaluation of UPJ obstruction.

Adolescent↗
PubMed1999

Prostate cancer screening in Tyrol, Austria: experience and results.

BACKGROUND: This article summarizes the experience and results of different prostate carcinoma screening projects using total prostate-specific antigen (PSA) and percent free PSA as the initial test. METHODS: The twelve projects studied included: (1) a mass screening study using PSA as the initial test in 21,079 volunteers; (2) an investigation of the usefulness of normal and age-referenced PSA cut-offs in 1,618 men; (3) a PSA-based screening study of 2,272 asymptomatic blood donors; (4) an investigation of the evidence and significance of transition zone carcinoma in 340 men with negative digital rectal examination findings; (5) determination of percent free PSA in one retrospective and two prospective studies to determine the appropriate cutpoints for percent free PSA; (6) evaluation of the diagnostic benefit of PSA transition zone density in 308 screening volunteers; (7) a study of the impact of PSA-based screening on the percentage of incidental prostate carcinoma in 1, 543 men undergoing transurethral resection of the prostate; (8) an evaluation of the changes in total PSA and pathologic stages in radical prostatectomy over 5 years in a PSA-based mass screening program; (9) a study evaluating the probability of having prostate cancer given the patient's age, total PSA and digital rectal examination findings; (10) an evaluation of the correlation between preoperative predictors and pathologic features in radical prostatectomy specimens; (11) an investigation of the correlation of total PSA with pathologic stage and tumor volume in patients undergoing radical prostatectomy with low PSA cut-off level, and (12) a study whether age has an impact on the extension of prostate cancer. RESULTS: (1) of the 21,079 volunteers, 1,618 (8%) had elevated PSA levels. Of these men, 778 (48%) underwent biopsies; 197 biopsies were positive for prostate carcinoma and 135 underwent radical prostatectomy. Ninety-five were found to be organ-confined. (2) A PSA cut-off of 2.5 ng/ml in men aged 45-49 years and of 3.5 ng/ml in men aged 50-59 years resulted in an 8% increase in the detection rate of organ-confined disease. (3) Of the 2,272 men, 284 had elevated PSA levels and prostate carcinoma was detected in 62 men. All patients underwent radical prostatectomy and histologic examination revealed organ-confined tumor in all but 8 men. (4) Ninety-eight of 340 men had biopsies positive for carcinoma; 28 of these patients (28.5%) had carcinoma that originated in the transition zone only. (5) In the retrospective study, receiver-operating characteristic curve analysis showed that by using a percent free PSA of 18% as a biopsy criterion, 37% of the negative biopsies could be eliminated although 94% of all carcinomas would still be detected. In the first prospective study, 106 of 158 men with elevated PSA levels <10.0 ng/ml were further evaluated and 37 prostate carcinomas were detected. By using a % free PSA of <22% as a biopsy criterion, 30% of the negative biopsies could be eliminated although 98% of the carcinomas would still be detected. In the second prospective study, 120 of 465 men with total PSA levels between 1.25 and 6.49 ng/ml and a % free PSA <18% were further evaluated and 27 (22.5%) were found to have prostate carcinomas. (6) Receiver-operating characteristic curve analysis for PSA transition zone density showed that by using a PSA transition zone density of >22 ng/ml/cm3 as a biopsy criterion, 24.4% of negative biopsies could be avoided without missing a single carcinoma. (7) In the prescreening era the incidence of T1a grade 1 and 2 carcinomas was 3.1% and the incidence of T1a grade 3 and T1b carcinoma was 2.3% whereas in the years after the establishment of PSA-based screening the incidence was 4.6 and 1.03% respectively. (8) The rate of organ-confined tumors increased from 28.7% in 1993 to 65.7% in 1997. (9) In this evaluation a new approach to proceed with a prostate biopsy based upon the individual risk of having prostate cancer rath

Adult↗
PubMed1999

Mechanism of androgen receptor activation and possible implications for chemoprevention trials.

Androgens are pivotal regulators of prostate cell growth, differentiation and function, and their actions are believed to be involved in prostate cancer development. The androgen-signaling pathway in the prostate gland is therefore one of the possible sites of intervention in prostate cancer prevention efforts. The central element of androgen signaling in the cell is the androgen receptor (AR), a member of the superfamily of nuclear receptors. Binding of androgen to its ligand-binding domain transforms the receptor to an active transcription factor that regulates gene expression by interacting with specific regulatory elements in the promoters of genes. In addition to this genomic action, the AR also interacts with other signaling pathways through protein-protein interaction, for example with AP-1 or Ets transcription factors. It is not only the action of androgenic hormones, but also the interactions with growth factor and protein kinase A-signaling pathways that can induce activation of AR. Moreover, these ligand-independent activators act synergistically together with low concentrations of androgens. The effects of long-term androgen deprivation on androgen signaling have been investigated in the LNCaP cell culture system. Long-term culture in a steroid-free medium results in a subline showing a hyperreactive AR characterized by increased AR expression and enhanced AR transcriptional activity in an environment with low levels of androgen hormones. It is not yet clear if similar changes also occur in normal or premalignant prostate epithelial cells and are thus relevant for prevention trials which interfere with androgen hormone signaling.

Antineoplastic Agents↗
PubMed1999

Importance of the renal resistive index in children suffering from vesicoureteral reflux.

OBJECTIVE: in our study, we wanted to assess changes and values of the renal resistive index (RI) in children with vesicoureteral reflux (VUR) using color Doppler ultrasound (CDUS) techniques. METHODS: We investigated 92 kidney units in 46 children (mean age 6 +/- 4 years) with VUR by means of CDUS. The RI was measured at the level of the interlobar and/or arcuate arteries using a color Doppler unit Acuson 128 XP/10. The CDUS findings were correlated with those obtained using standard renal scintigraphy. RESULTS: Children with VUR grades I-III showed a RI of 0.6 +/- 0.07, whereas patients suffering from VUR grades IV and V demonstrated a significantly increased RI of 0.77 +/- 0.07 (p < 0.0001). The correlation of the CDUS measurements with the scintigraphic findings revealed a positive correlation coefficient of r2 = 0.61. CONCLUSIONS: CDUS seems to be a helpful, radiation-free, noninvasive, and inexpensive tool in children with VUR, demonstrating a significant change in the RI especially in high-grade reflux. Moreover, the RI findings represent a good correlation with standard renal scintigraphy. Therefore, CDUS with assessment of the RI allows a perfect follow-up study of affected children.

Age Factors↗
PubMed1999

Cryptorchidism, open processus vaginalis, and associated hernia: laparoscopic approach to the internal inguinal ring.

OBJECTIVES: A nonpalpable testis was the first indication for laparoscopy in urology. This primarily diagnostic procedure has evolved to complete laparoscopic orchidopexy. An associated inguinal hernia due to an open processus vaginalis is reported in 26% of cryptorchidism cases. Simultaneous laparoscopic orchidopexy and herniorrhaphy are therefore the next logical step. METHODS: Between 1992 and 1998, 61 children underwent laparoscopy for pathology of the internal inguinal ring. In 48 boys the operation was performed for a nonpalpable testis and in 13 boys laparoscopic transection of the processus vaginalis was performed because of clinical hydrocele. RESULTS: In 25 of the 48 cases an intra-abdominal location was found with 18 existing and 7 vanishing testicles. Laparoscopic orchidopexy was performed either as a two-stage Fowler-Stephens technique (n = 6) or as a direct one-stage repair (n = 12). In 6 boys with cryptorchidism a direct inguinal hernia was associated, which received simultaneous laparoscopic herniorrhaphy. In 23 cases of cryptorchidism with an inguinal location of the testis, 3 vanishing testicles were found. In 20 cases with normal testicular vessels, an inguinal exploration followed. In 4 of the hydrocele cases additional herniorrhaphy had to be performed. In all cases the operation could be performed as planned without complications. After orchidopexy all testicles were in the normal position and well perfused as revealed by flow Doppler sonography. All hydroceles disappeared within several days. There was no inguinal hernia recurrence. CONCLUSIONS: Laparoscopic dissection of the internal inguinal ring allows perfect delineation of the anatomic structures and their relationship. Transection of the processus vaginalis can be performed without disturbance of the inguinal canal. Hernias can be closed with essentially the same technique as used in open surgery. Morbidity was minimal in all patients.

Child, Preschool↗
PubMed1999

Mature dendritic cells induce T-helper type-1-dominant immune responses in patients with metastatic renal cell carcinoma.

We performed a pilot study on a dendritic cell (DC)-based vaccine in 4 patients with advanced renal cell carcinoma. The vaccine consisted of cultured blood DCs loaded with autologous tumor cell lysate plus keyhole limpet hemocyanin (KLH) and matured with a combination of tumor necrosis factor alpha and prostaglandin E(2). We describe the immune response against KLH induced by DC-based immunization in a patient undergoing an objective partial response and compare it with the responses observed in patients with either stable or progressive disease. The patient with the clinical response developed strong delayed-type hypersensitivity (DTH) against KLH after a single vaccination with antigen-loaded DCs, whereas the other patients failed to develop DTH reactivity even after repeated vaccinations. Antigenic stimulation of mononuclear cells (MNCs) induced proliferation and IFN-gamma but not IL-4 production as well as expression of the chemokine receptor CXCR3 consistent with a T-helper (Th) type-1 bias. Exogenous IL-12 enhanced and exogenous IL-4 diminished IFN-gamma production. In the 2 patients with stable disease two or more vaccinations were required to induce maximal MNC responses. In the patient with progressive disease MNC responses were hardly detectable. Anti-KLH antibodies appeared with different kinetics but could be detected in the serum of all patients. Isotype analysis revealed the presence of IgM, IgG(1), IgG(2) and IgG(3) as well as IgA and complete absence of IgE. The patient with progressive disease also developed IgG(4) antibodies indicative of a deviation towards Th2. Cultured blood DCs can be a potent vaccine for the antigen-specific immunization of patients with advanced kidney cancer. KLH serves as a tracer molecule which allows determination of the magnitude, kinetics and Th bias of the cellular and humoral immune response induced by DC-based immunization. The data also suggest that Th type-1-dominant immune responses involving DTH reaction are required for the induction of tumor regression.

Adjuvants, Immunologic↗
PubMed1999

Cellular and humoral immune responses in patients with metastatic renal cell carcinoma after vaccination with antigen pulsed dendritic cells.

PURPOSE: Dendritic cells are the most potent stimulators of immune responses including antitumor responses. We performed a pilot study of cultured antigen loaded dendritic cells in patients with metastatic renal cell carcinoma. MATERIALS AND METHODS: Dendritic cells were obtained by culturing plastic adherent mononuclear cells from peripheral blood for 5 days in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4. Day 5 dendritic cells were loaded with cell lysate from cultured autologous tumor cells and with the immunogenic protein keyhole-limpet hemocyanin (KLH) which serves as a helper antigen and as a tracer molecule. During the antigen pulse dendritic cells were activated with a combination of tumor necrosis factor-alpha and prostaglandin E2. Dendritic cells were administered by 3 intravenous infusions at monthly intervals. Cellular and humoral immune responses to KLH and cell lysate were measured in vitro before and after the vaccinations. RESULTS: Preparation of 12 dendritic cell vaccines from patients with advanced renal cell carcinoma was successful. Treatment with fully activated CD83+ dendritic cells was well tolerated with moderate fever as the only side effect. Potent immunological responses to KLH and, most importantly, against cell lysate could be measured in vitro after the vaccinations. CONCLUSIONS: Our data demonstrate that a dendritic cell based vaccine can induce antigen specific immunity in patients with metastatic renal cell carcinoma. Dendritic cell based immunotherapy represents a feasible, well tolerated and promising new approach for the treatment of advanced renal cell carcinoma.

Aged↗
PubMed1999

Development of a new biodegradable intravascular polymer stent with simultaneous incorporation of bioactive substances.

OBJECTIVE: Due to the thrombogenicity and permanent implant nature of metallic stents, bioresorable synthetic polymers have been proposed for stents and local drug delivery systems. Bioresorbable polyesters like poly(D,L-lactide) demonstrated excellent biocompatibility in various tissues. This paper describes a novel method for the molding of these polymers. The specific CESP-process (Controlled Expansion of Saturated Polymers) is characterised by the use of the plasticizer carbon dioxide and allows the incorporation of bioactive substances at physiologic temperatures into the polymer bulk and the production of complex designed implants. METHODS: The CESP-process is characterised by the exposure of an amorphous polymer to an inert gas at high pressure with a significant lower glass transition point. The plasticizing effect makes it possible to process polylactides at a temperature close to room temperature. The low process temperature constitutes a key advantage for thermally sensitive polymers and allows the incorporation of thermally sensitive pharmaceutical additives. To obtain some preliminary information on the biocompatibility, in vitro cell toxicity testing as well as drug release assessment was performed. RESULTS: Different polymer sheets were produced using the CESP-process. Cytotoxicity was not observed in any molded polymer material. According to the mechanical and biocompatibility results Poly(D,L-lactide) (P-DL-LA) was investigated in the CESP-process. Finite element analysis was used to test the possible geometry of an adequate stent. A helical design was chosen and a stent-prototype was produced using the CESP-process. Peroxidase activity as an incorporated marker enzyme could be measured over 6 weeks. Different drug release profiles were obtained due to various pore sizes of the polymer. CONCLUSIONS: The new CESP-process can be used to process biodegradable polymers and to mold different stent geometries without inducing cytotoxic effects to the material. Furthermore, this procedure permits the simultaneous incorporation of bioactive substances during the molding process. Drug release kinetics can be regulated by different pore sizes of the material.

Absorbable Implants↗
PubMed1999

Laparoscopic retroperitoneal lymphadenectomy after chemotherapy for stage IIB nonseminomatous testicular carcinoma.

PURPOSE: We investigated laparoscopic retroperitoneal lymphadenectomy after chemotherapy for stage IIB testicular carcinoma in terms of operative feasibility, overall morbidity and tumor control. MATERIALS AND METHODS: Between February 1995 and April 1998, 24 patients underwent laparoscopic retroperitoneal lymphadenectomy following initial chemotherapy for stage IIB (2 to 5 cm.) solitary or unilateral lymph node metastases. Mean tumor diameter was 2.4 cm. before and 1.1 cm. after chemotherapy. Laparoscopic retroperitoneal lymphadenectomy was performed in all patients, including those with complete remission. RESULTS: Laparoscopic retroperitoneal lymphadenectomy could be completed as planned in all patients and there was no need for conversion to open surgery. Operative time was 150 to 300 minutes (mean 240). Blood loss was minimal and no blood transfusions were required. The only postoperative complications were chylous ascites (5 patients) which resolved with conservative management (low fat diet) and a small asymptomatic lymphocele. Histological examination revealed necrosis in 71%, mature teratoma in 25% and active tumor in 4% of patients. Antegrade ejaculation was preserved in all patients. Mean postoperative hospital stay was 4 days, return to normal activities between 1 and 3 weeks, and time to complete recovery between 5 and 10 weeks. All patients were well without evidence of disease at a mean followup of 24.4 months. CONCLUSIONS: Laparoscopic retroperitoneal lymphadenectomy after chemotherapy proved feasible in select patients presenting with solitary or unilateral lymph node metastases and was associated with a low morbidity. Tumor control was not compromised by the laparoscopic approach.

Adolescent↗
PubMed1998

Videoimaging of prostatic stromal-cell contraction: an in vitro model for studying drug effects.

BACKGROUND: Stromal-cell contractility is known to play an important role in the development of bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH). An in vitro model of single-cell contraction was developed to investigate the effect of alpha1-adrenoceptor agonists and antagonists. METHODS: Human prostatic stromal cells were isolated from prostatectomy and cystoprostatectomy specimens. The cells were cultured in a selective medium supplemented with growth factors and steroid hormones. The culture flasks were coated with a viscous agent to allow cell contraction. Contractions were visualized by means of a cell-culture microscope fitted with a time-lapse video system. For quantitative analysis, the percentage of contracting cells was evaluated. RESULTS: Nineteen percent of the cells were found to contract without stimulation. Following incubation with doxazosin (10 nM, 100 nM, and 1 mM), there was a slight dose-dependent decrease in the number of spontaneously contracting cells, whereas adrenergic stimulation using 10 microM of phenylephrine led to a significant increase in the percentage of contracting cells (55%). Following incubation with 100 nM of doxazosin, the phenylephrine-induced effect was significantly reduced. CONCLUSIONS: This simple in vitro model of cell contraction in the prostate provides a useful means of investigating drug effects on prostatic stromal cells.

Adrenergic alpha-Agonists↗
PubMed1998

Improvement of specificity in PSA-based screening by using PSA-transition zone density and percent free PSA in addition to total PSA levels.

BACKGROUND: The clinical value of prostate-specific antigen (PSA) density in differentiating between prostate cancer and benign prostatic hyperplasia has been the subject of several studies. In this context the question has been raised about the diagnostic benefit of PSA transition-zone density (PSA-TZ density = total PSA/transition-zone volume) in the detection of prostate cancer. In the following study the value of PSA-TZ density alone and in combination with free PSA was investigated. METHODS: Between August 1995-May 1996, 308 first-line screening volunteers with elevated total PSA levels ranging from 2.5-10.0 ng/ml were evaluated. All patients underwent digital rectal examination, transrectal ultrasound, and transrectal ultrasound-guided biopsy of the prostate. Prior to these investigations, serum was obtained and total as well as free PSA levels were obtained. PSA transition-zone density (PSA-TZ density) was defined as follows: PSA-TZ density = total PSA/transition-zone volume. RESULTS: ROC curve analyses for PSA-TZ density showed that by using a PSA-TZ density of more than 0.22 ng/ml/cc as a biopsy criterion, 24.4% of negative biopsies could be avoided; ROC curve analyses for free PSA showed that by using percent free PSA <20% as a biopsy criterion, 45.5% of negative biopsies could be eliminated. When combining these two diagnostic tests, 54.2% of negative biopsies could be avoided. CONCLUSIONS: We conclude that PSA-TZ density, in addition to total and free PSA, is a new opportunity which renders it possible to calculate the likelihood of detecting prostate cancer on repeat biopsies in an individual patient.

Biopsy↗