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Alan W Partin

Publications and source records attributed to Alan W Partin.

At least 91 records · Page 5Linked to original sources
PubMed2003

PSA markers in prostate cancer detection.

The PSA revolution that has occurred over the previous 2 decades has positively impacted the detection and treatment of men with prostate cancer. Although methods to improve specificity have shown promise (eg, PSAD, age-specific PSA, and PSA velocity), meaningful interpretation has yet to be uniformly accepted within clinical practice. The identification of other molecular forms of PSA within serum has led to a new era in PSA markers. Initial application employing %fPSA has provided improved discrimination between benign and malignant prostatic disease; however, questions remain regarding the ultimate threshold value. The discovery of various free forms of PSA--such as proPSA, BPSA, and iPSA--also have introduced the potential for improved specificity in detection. Although early results are encouraging, further evaluation is anticipated. The development of improved methods to detect and measure cPSA has demonstrated provocative results, and exhibits the potential to replace PSA as a standard diagnostic test in cancer screening.

Humans↗
PubMed2003

Biochemical (prostate specific antigen) recurrence probability following radical prostatectomy for clinically localized prostate cancer.

PURPOSE: We retrospectively reviewed the clinical followup for a large series of men with clinically localized prostate cancer who underwent radical retropubic prostatectomy to identify clinical and/or pathological indicators of biochemical (prostate specific antigen [PSA]) recurrence. We then used those indicators to develop multivariate models for determination of recurrence probability following radical retropubic prostatectomy. MATERIALS AND METHODS: From 1982 to 1999, 2,091 consecutive men underwent radical retropubic prostatectomy and pelvic lymphadenectomy for clinically localized adenocarcinoma of the prostate (clinical stage T1c or T2 disease with Gleason score 5 or greater). Actuarial analysis was performed comparing freedom from biochemical recurrence after radical retropubic prostatectomy (PSA 0.2 ng./ml. or greater.) using the Kaplan-Meier method. Event time distributions for the time to recurrence were compared using the log rank statistic or the Cox proportional hazards regression model. The first model was developed using preoperative variables only and the second model using all available variables. Observed and predicted recurrence-free survival curves for different models were compared to select a model for calculation of predicted recurrence-free probabilities and confidence intervals. RESULTS: With a median followup of 5.9 years (range 1 to 17) 360 men (17%) had biochemical recurrence. Overall actuarial 5, 10 and 15-year biochemical recurrence-free survival rates were 84%, 72% and 61%, respectively. The relative risk of biochemical recurrence following surgery decreased with time, even after adjusted for other perioperative parameters. Variables identified for the preoperative model were biopsy Gleason score, clinical TNM stage and PSA. Variables identified for the postoperative model were prostatectomy Gleason score, PSA and pathological organ confinement status. Nomograms were generated and corrected for the decreasing relative risk of biochemical recurrence over time. CONCLUSIONS: Using 3 preoperative or postoperative parameters, these nomograms can easily be used to determine the 3, 5, 7 and 10-year biochemical recurrence-free survival probabilities among men who undergo radical retropubic prostatectomy for clinically localized prostate cancer in the modern era.

Adenocarcinoma↗
PubMed2003

Evaluation of proprostate specific antigen for early detection of prostate cancer in men with a total prostate specific antigen range of 4.0 to 10.0 ng/ml.

PURPOSE: In contemporary screening populations a major drawback of prostate specific antigen (PSA) is its relative lack of specificity, especially in the range of 4 to 10 ng/ml, where prostate cancer is found 25% of the time. ProPSA is a derivative of free PSA (fPSA) consisting of the truncated forms (eg [-2]proPSA, [-4]proPSA or the full-length [-7]proPSA). There is increasing evidence that proPSA is associated preferentially with prostate cancer. The objective of this study was to determine whether proPSA can influence the detection of early prostate cancer. MATERIALS AND METHODS: Archival serum samples obtained from 93 men who underwent a systematic 12-core prostate biopsy (total PSA range 4.0 to 10.0 ng/ml) were assayed for percent free PSA, total PSA and the 3 forms of proPSA (Hybritech Tandem Assays Beckman Coulter Access, Beckman Coulter, Inc., Brea, California). Free PSA, the cumulative sum of individual proPSA forms ([-2], [-4] and [-7], or sum-proPSA) and derivatives were determined. Of the 93 men assessed 41 (44%) had evidence of prostate cancer (76% Gleason 5/6, 19% Gleason 7 and 5% Gleason 8). Prostate volume was measured at systematic 12-core biopsy for the detection of prostate cancer. Results were analyzed using univariate and multivariate logistic regression (LR) nonparametric statistical methods. RESULTS: Using univariate LR, fPSA, percent fPSA (%fPSA), percent sum-proPSA and prostate volume significantly (p <0.05) differentiated men with prostate cancer from those with benign disease. However, applying stepwise backward multivariate LR, total PSA, %fPSA and sum-proPSA were retained and generated a receiver operator characteristic curve with an area under the curve of 76.6%. At 90% sensitivity these 3 variables collectively achieved a specificity of 44% for the detection of prostate cancer. Individually, the 3 retained variables had a specificity of 23% (total PSA), 33% (%fPSA) and 13% (sum-proPSA). CONCLUSIONS: Sum-proPSA, total PSA and %fPSA in combination improve the specificity of early prostate cancer detection in men with a total PSA of 4 to 10 ng/ml compared with the results of individual PSA molecular forms measured.

Adenocarcinoma↗
PubMed2003

The evolving role of docetaxel in the management of androgen independent prostate cancer.

PURPOSE: Androgen independent prostate cancer is an advanced disease with an extremely poor outcome. In view of this fact, a great deal of interest has recently been generated in the potential use of chemotherapeutic agents, particularly docetaxel. We reviewed the evolving role of docetaxel as a chemotherapeutic agent for the management of this disease. MATERIALS AND METHODS: The main emphasis of this review is discussion of the various clinical trials that have investigated the use of docetaxel alone or combined with other agents for androgen independent prostate cancer. RESULTS: Docetaxel, which acts primarily by inhibiting microtubular depolymerization, in combination with other agents has consistently demonstrated a palliative response, a decrease in serum prostate specific antigen levels by 50% or greater in more than 60% of patients, a decrease in measurable disease and the suggestion of improved survival. CONCLUSIONS: Docetaxel based regimens are moderately well tolerated and they have shown promising results in various phase 2 trials. The completion of ongoing phase III randomized trials are eagerly awaited since they may determine whether a definite beneficial impact on overall survival can be achieved.

Antineoplastic Agents, Phytogenic↗
PubMed2003

Complexed prostate specific antigen improves specificity for prostate cancer detection: results of a prospective multicenter clinical trial.

PURPOSE: Complexed (c) prostate specific antigen (PSA) has been shown to enhance specificity for prostate cancer (CaP) detection over total PSA (tPSA), although a large multi-institutional prospective evaluation was required to confirm these findings. We compared the clinical performance of cPSA with tPSA as a first line test for CaP detection and secondarily to determine if PSA ratios, namely percent free PSA (fPSA) and percent cPSA, can provide further enhancement in diagnostic performance over cPSA or tPSA. MATERIALS AND METHODS: Consecutive men scheduled for initial biopsy of the prostate were enrolled prospectively at each of 7 university centers and community based urology practices. Serum was collected and tested with the Immuno 1 (Bayer Diagnostics, Tarrytown, New York), tPSA and cPSA, and Access (Beckman, Inc., San Diego, California) fPSA and tPSA methods. RESULTS: A total of 831 patients were evaluated, of whom 313 (37.5%) were diagnosed with CaP. ROC curve analysis performed from the results of all samples and those within the clinically relevant cPSA ranges of 1.5 to 3.2, 1.5 to 5.1, 1.5 to 8.3 and 3.2 to 8.3 ng/ml (tPSA 2 to 4, 2 to 6, 2 to 10 and 4 to 10 ng/ml, respectively) indicated a significant improvement in the AUC ROC curve for cPSA compared with tPSA (p < or =0.001). Using cutoff points that provide a sensitivity of 80% to 95% for CaP detection within the 1.5 to 8.3 ng/ml cPSA range cPSA provided a statistically significant enhancement in specificity over tPSA of 6.2% to 7.9%. Within the cPSA range of 1.5 to 3.2 ng/ml using a cutoff point of 2.5 ng/ml for tPSA and 2.2 ng/ml for cPSA provided a specificity of 21.2% and 35%, respectively, and 85% sensitivity for CaP detection. PSA ratios provided no further enhancement in specificity over cPSA within these ranges. CONCLUSIONS: The use of cPSA as a single test provided improved specificity over tPSA. Percent fPSA and percent cPSA offered little to no additional benefit in the differentiation of benign and malignant disease at clinically relevant cPSA concentrations.

Aged↗
PubMed2003

Can prostate specific antigen derivatives and pathological parameters predict significant change in expectant management criteria for prostate cancer?

PURPOSE: A prior report established that pretreatment criteria based on clinical and biopsy pathology parameters can predict men who harbor small volume prostate cancer who might be followed expectantly. However, some of these men will exhibit disease progression with time and will need definitive therapy. To detect those in whom disease may progress, repeat prostate biopsies are performed at yearly intervals. Therefore, we determined whether biomarkers could be used to determine those in whom disease is likely to progress and thus those who require definitive therapy. MATERIALS AND METHODS: Initial and repeat biopsy information along with transrectal ultrasound measurements of gland volume, total prostate specific antigen (PSA), %free PSA (%fPSA) and total PSA velocity were evaluated in 78 men, 45 from the prior study, in whom disease was being managed expectantly. Univariate and multivariate logistic regression analyses determined variables that predicted a favorable tumor burden based on biopsy pathology status at each subsequent repeat biopsy. A Cox proportional hazards model was produced using 67 of 78 evaluable cases having adequate temporal data to predict hazard ratios for conversion from favorable to unfavorable tumor burden status. RESULTS: At time zero for 78 patients %fPSA, total PSA, and gland volume univariately and multivariately differentiated unfavorable and favorable tumor burden groups (p <0.05). The receiver operator characteristic area under the curve (ROC-AUC) was 83%. At the first followup biopsy 17 of 67 (25.4%) men converted to unfavorable tumor burden status. The %fPSA, PSA velocity and gland volume univariately distinguished these 2 groups (p <0.05) with 82% ROC-AUC. At second repeat biopsy 6 of 36 (16.7%) men converted to unfavorable tumor burden status and the ROC-AUC was 76%. Of the 14 men who had a third repeat biopsy all demonstrated favorable tumor burden status. A Cox proportional hazards model stratified the 67 of 78 men into high (48) and low risk (19) groups based on %fPSA at a 20% cutoff (p <0.01). Classification and regression tree analysis using logistic regression multivariately selected variables predicted favorable tumor burden status with an accuracy that ranged from 75% to 84% during our study. CONCLUSIONS: PSA velocity, %fPSA and gland volume information improves the prediction of men undergoing expectant management who are more likely to have small volume disease based on a 12-core biopsy interpretation within the time of our observations. %fPSA proved to be a valuable marker to stratify the 2 risk groups. Therefore, based on these factors it may be possible to consider deferment of repeat prostate biopsy until adverse results are detected. This rational approach to the management of prostate cancer in older men with small volume cancer seems to be a reasonable strategy.

Aged↗
PubMed2003

Standardization of two immunoassays for human glandular kallikrein 2.

BACKGROUND: Measurement of human kallikrein 2 (hK2) has improved early detection and staging of prostate cancer. However, reported concentrations of hK2 among currently used assays have not been standardized in any way. We compared two hK2 assays and five different recombinant hK2 variants (rhK2) and suggest a common calibrator as an important step and putative reference substance in hK2 assay standardization. METHODS: We measured 146 sera by two hK2 assays, using assay-specific calibrators to assess the difference between the two assays. Serial dilutions of five rhK2 preparations were measured repeatedly, with one preparation assigned as calibrator and the others as unknowns to define which variant provided the closest match between the two assays. This rhK2 variant was used to recalibrate both assays. We measured hK2 concentrations in the same 146 patients to evaluate the change in the difference. RESULTS: Use of assay-specific calibrators for comparison of the two assays yielded a Deming regression equation of: y = 0.789 (95% confidence interval, 0.674-0.922)x + 0.014 (0.004-0.025) micro g/L; R(2) = 0.667. Analysis of five rhK2 variants revealed that the enterokinase (ek)-rhK2 form provided the best match between both assays. Using the ek-rhK2 as a common calibrator, we observed a change in the slope of the regression curve to: y = 1.106 (0.872-1.340)x + 0.006 (-0.002 to 0.016) micro g/L; R(2) = 0.648, suggesting an increase in the mean estimate of agreement between the two assays. CONCLUSION: Calibration with a common calibrator substantially increased agreement between the assays. The ek-rhK2 variant provided the best performance of all tested rhK2 variants and should undergo mass spectrometry and amino acid analysis for exact mass determination and value assignment to evaluate its potential as a reference material for immunoassays for hK2.

Biomarkers, Tumor↗
PubMed2003

Management of high-risk populations with locally advanced prostate cancer.

Prostate cancer that extends beyond the confines of the prostatic gland on clinical and/or radiographic assessment, without evidence of lymph node or distant metastases, is regarded as locally advanced. The locally advanced prostate cancer patient population consists of a heterogeneous group of men, some of whom have tumors that may be amenable to primary curative intent with local definitive therapy associated with acceptable long-term cancer control rates. In order to optimally manage this group of patients, it is important to be able to recognize who is at a high risk of tumor recurrence after primary local therapy. In this brief review, we discuss the factors that contribute to the prediction of high risk in populations with locally advanced disease and the treatment options available.

Cause of Death↗
PubMed2003

Comparison of total prostate-specific antigen and derivative levels in a screening population of black, white, and Korean-American men.

Numerous studies have assessed serum total PSA (tPSA) levels among different races. We extended the serum biomarker profiling using prostate-specific antigen (PSA) derivatives in age-matched screening populations that included white, black, and Korean-American patients. The median ages were 61 years for white and black patients and 63 years for Korean-American patients. Serum samples from 70 men in each ethnic group were analyzed using 3 different tPSA assays (Tosoh AIA 600II, Bayer Immuno-1, Roche Elecsys 2010). The percentage of free PSA (fPSA) was measured directly by Roche Elecsys 2010 immunoassay and then calculated from complexed PSA (cPSA) and tPSA results determined with the Bayer Immuno-1. The percentage of cPSA was determined using cPSA and tPSA assayed by the Immuno-1 method. Statistical analyses included nonparametric Kruskal-Wallis and analysis of variance (ANOVA) evaluations. There were no differences noted in the tPSA values based on ANOVA among the 3 races irrespective of the assay platform methodology employed. Also, the PSA derivatives, percentages of fPSA and cPSA, evaluated using the Kruskal-Wallis test, showed no significant differences for either derivative assayed on 2 different assay platforms among the 3 groups. In a contemporary screening population comparing tPSA, percentage of fPSA, and percentage of cPSA levels in 3 races, there were no significant differences identified among the groups.

Black or African American↗
PubMed2003

Modern Tumor Marker Discovery in Urology: Surface Enhanced Laser Desorption and Ionization (SELDI).

During the last two decades, biomarker research has benefited from the introduction of new proteomic analytical techniques. In this article, we review the application of surface enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectroscopy in urologic cancer research. After reviewing the literature from MEDLINE on proteomics and urologic oncology, we found that SELDI-TOF is an emerging proteomic technology in biomarker discovery that allows for rapid and sensitive analysis of complex protein mixtures. SELDI-TOF is a novel proteomic technology that has the potential to contribute further to the understanding and clinical exploitation of new, clinically relevant biomarkers.

Journal Article↗
PubMed2002

Germline mutations and sequence variants of the macrophage scavenger receptor 1 gene are associated with prostate cancer risk.

Deletions on human chromosome 8p22-23 in prostate cancer cells and linkage studies in families affected with hereditary prostate cancer (HPC) have implicated this region in the development of prostate cancer. The macrophage scavenger receptor 1 gene (MSR1, also known as SR-A) is located at 8p22 and functions in several processes proposed to be relevant to prostate carcinogenesis. Here we report the results of genetic analyses that indicate that mutations in MSR1 may be associated with risk of prostate cancer. Among families affected with HPC, we identified six rare missense mutations and one nonsense mutation in MSR1. A family-based linkage and association test indicated that these mutations co-segregate with prostate cancer (P = 0.0007). In addition, among men of European descent, MSR1 mutations were detected in 4.4% of individuals affected with non-HPC as compared with 0.8% of unaffected men (P = 0.009). Among African American men, these values were 12.5% and 1.8%, respectively (P = 0.01). These results show that MSR1 may be important in susceptibility to prostate cancer in men of both African American and European descent.

Aged↗
PubMed2002

Validation of a biopsy-based pathologic algorithm for predicting lymph node metastases in patients with clinically localized prostate carcinoma.

BACKGROUND: The authors validated an algorithm for the preoperative prediction of lymph node (LN) metastases in patients with clinically localized prostate carcinoma. The algorithm was applied to sextant biopsy material and radical retropubic prostatectomy (RRP) stage obtained from a cohort of men who were treated at the authors' institution. METHODS: Four hundred forty-three patients underwent systematic sextant biopsy and RRP with staging lymphadenectomy. The original algorithm was based on systematic sextant biopsy data and classified patients into three risk groups for LN metastases based on the biopsy result. If > or = 4 of 6 biopsies contained any Gleason Pattern 4 disease, then the patient was at high risk for LN metastases (45%). Patients with > or = 1 of 6 biopsies with dominant Gleason Pattern 4 disease (excluding high-risk patients) had an intermediate predicted risk (19%) of LN metastases. All other patients had a low predicted risk of LN metastases (2.2%). The authors assed the percentage of patients who were positive and negative for LN metastases and calculated the specificity and negative predictive value in the series when patients were classified according to the original algorithm. RESULTS: Twenty of 443 patients had intraoperative LN metastases. When applied to the current data, the Hamburg algorithm classified 404 patients in the low-risk group, 30 patients in the intermediate-risk group, and 9 patients in the high risk group. The incidence of LN metastases was 2.47% in the low-risk group, 20% in the intermediate-risk group, and 44.4% in the high-risk group. The negative predictive value for the low-risk group was 97.52%, and the specificity was 94.14%. CONCLUSIONS: The Hamburg algorithm proved a valid tool for the prediction of lymphatic spread in this validation study on data from the authors' institution. The algorithm may serve as a tool to select patients who do not need to undergo pelvic lymphadenectomy at the time they undergo RRP, hence reducing morbidity and expense. More importantly, with the increasing numbers of men undergoing treatment options in whom LN dissection is not performed, this validated algorithm provides an important selection basis regarding the appropriateness of a therapy that does not routinely include LN staging.

Algorithms↗
PubMed2002

Clinical utility of indium 111-capromab pendetide immunoscintigraphy in the detection of early, recurrent prostate carcinoma after radical prostatectomy.

BACKGROUND: Despite the ability of radical prostatectomy to eradicate prostate carcinoma, biochemical evidence of recurrent prostate carcinoma may be seen in approximately 40% of patients 15 years after they undergo surgery. Localization of recurrent disease after radical prostatectomy is difficult and may greatly influence subsequent clinical management. The authors examined the utility of indium 111 ((111)In)-capromab pendetide immunoscintigraphy to detect recurrent prostate carcinoma radiographically in men with early biochemical evidence of failure (serum prostate specific antigen [PSA] < or = 4.0 ng/mL) and assessed the minimum serum PSA level necessary for imaging recurrent disease. METHODS: Between May 1987 and August 1995, 255 hormone-naïve men with a mean (+/- standard deviation) age of 65 years +/- 7 years who underwent radical prostatectomy for clinically localized prostate carcinoma were followed without adjuvant therapy until early PSA recurrence in this multicenter study. Preoperatively, all patients had negative bone scans and pathologically negative lymph nodes, and they did not undergo hormonal ablation, chemotherapy, or radiation therapy preoperatively or postoperatively until the (111)In-capromab pendetide scan was performed. All men in this study had postoperative serum PSA levels < or = 4.0 ng/mL at the time of radionuclide imaging. All men underwent imaging with the capromab pendetide scan to localize recurrent disease, and charts were reviewed to document clinical evidence of recurrence. RESULTS: Pathologic findings included mean Gleason scores of 6.7 +/- 1.2; pathologic tumors classified as pT2a (18%), pT2b (26%), pT3a (38%), pT3b (16%), and pT4a (2%); a pathologic lymph node status of pN0 (100%); positive surgical margins (44%); and perineural invasion (42%). Capromab pendetide uptake was seen in 72% of 255 men throughout a range of patients' postoperative serum PSA levels (0.1-4.0 ng/mL), with 31% of men having local uptake (prostatic fossa) only. Of 151 men who underwent additional imaging studies, 16 of 139 men (12%) and 15 of 92 men (16%) showed evidence of recurrent disease by bone scintigraphy and computed tomography scans, respectively. Gleason score, pathologic stage, perineural invasion, and margin status were not correlated significantly with the (111)In-capromab pendetide scan. CONCLUSIONS: Capromab pendetide imaging can localize early PSA recurrence and may guide appropriate treatment after patients undergo radical prostatectomy. No minimum serum PSA value was needed to potentially detect radiographic disease after surgery. Further confirmatory studies and long-term follow-up of this cohort documenting response to salvage therapy are needed to validate these imaging findings.

Aged↗