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P F Schellhammer

Publications and source records attributed to P F Schellhammer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Serum prostate specific antigen is a strong predictor of future prostate growth in men with benign prostatic hyperplasia. PROSCAR long-term efficacy and safety study.

PURPOSE: We analyze patterns of prostate growth in men diagnosed with benign prostatic hyperplasia (BPH) and treated with placebo during 4 years, and determine which baseline parameters were the strongest predictors of growth. MATERIALS AND METHODS: A total of 3,040 men were enrolled in the 4-year randomized, placebo controlled Proscar Long-Term Efficacy and Safety study. Of these men a subgroup of 10% underwent pelvic magnetic resonance imaging prostate volume measurement at baseline and yearly thereafter. Absolute and percent volume changes during 4 years were calculated in the 164 placebo treated men in the subgroup. The ability of age, baseline prostate volume and prostate specific antigen (PSA) to predict prostate growth in placebo treated patients was assessed by multiple linear regression analyses, receiver operator characteristics curves, and evaluations of growth stratified by tertiles of baseline serum PSA and decades of life. RESULTS: In placebo treated patients a steady increase in mean plus or minus standard deviation prostate volume from year to year was noted (2.5+/-6.1, 4.9+/-6.8, 6.4+/-8.5 and 7.2+/-8.8 ml. at years 1, 2, 3 and 4, respectively). Mean volume changes at 4 years ranged from -9 to +30 ml. Mean percent change from baseline ranged from 12.5% to 16.6% for men 50 to 59 years old to those 70 to 79 years old. Baseline serum PSA was a strong predictor of growth with 7.4% to 22.0% change at 4 years from the lowest to highest PSA tertiles. Annualized growth rates from baseline were 0.7 ml. per year for PSA 0.2 to 1.3, 2.1 for PSA 1.4 to 3.2 and 3.3 for PSA 3.3 to 9.9 ng./ml. Multiple linear regression analysis showed that serum PSA was a stronger predictor of prostate growth than age or baseline prostate volume. All but 1 man with baseline serum PSA greater than 2.0 ng./ml. had prostate growth during 4 years, and 32.6% of men with serum PSA less than 2.0 exhibited a decrease in volume. CONCLUSIONS: Serum PSA is a stronger predictor of growth of the prostate in placebo treated patients than age or baseline prostate volume. Since prostate volume is a risk factor for acute urinary retention and the need for BPH related surgery, the ability of PSA to predict prostate growth may be an important factor when considering individual treatment options for BPH. Such use of PSA represents a shift in paradigm away from focusing solely on symptoms of BPH toward a more comprehensive approach with consideration of predicting and preventing risk factors of BPH related outcomes.

Aged↗
PubMed2000

Outcomes after intravesical bacillus Calmette-Guerin are not affected by substaging of high grade T1 transitional cell carcinoma.

PURPOSE: Substaging of T1 bladder tumors into T1a and T1b based on invasion of the tumor superficial to and beyond the muscularis mucosa has been assigned prognostic significance. We determined whether outcomes after intravesical bacillus Calmette-Guerin (BCG) differ between stage T1a and T1b subcategories. MATERIALS AND METHODS: Retrospective pathological evaluation of the initial transurethral resection specimens of stage T1 bladder tumors was performed by 2 pathologists. Grade 1, 2 or 3 and stage T1a or T1b were assigned to each case. Followup was from the date of transurethral resection to date of death or the last visit. Kaplan-Meier probability and log rank test were used to evaluate recurrence and progression. RESULTS: Substaging was performed in 49 of the 55 patients (89%) with stage T1 disease. Disease was stage T1a in 32 (65%), stage T1b in 17 (35%), grade 3 in 45 (92%) and grade 2 in 4 (8%) cases. Maximum followup was 147 months (median 71) and 28 cases had a minimum of 5 years of followup. Recurrence was noted in 33 cases (67.3%), including 22 stage T1a (69%) and 11 stage T1b (65%), at a median followup of 11.3 and 8.6 months, respectively. Progression to a higher stage of disease was recorded in 12 cases (24.4%), including 7 (22%) stage T1a and 5 (29%) stage T1b, at a median followup of 108 and 120 months, respectively. The difference between T1a and T1b subcategories was not statistically significant in regard to recurrence-free (p = 0.7203) and progression-free (p = 0.574) outcomes. CONCLUSIONS: Substaging of T1 tumors did not affect response to BCG in regard to recurrence or progression. Therefore, intravesical BCG is effective for stages T1a and T1b disease.

Adjuvants, Immunologic↗
PubMed1999

Exploratory analysis on the effect of race on clinical outcome in patients with advanced prostate cancer receiving bicalutamide or flutamide, each in combination with LHRH analogues. The Casodex Combination Study Group.

BACKGROUND: Black race has been associated with a significantly increased risk of prostate cancer mortality. This exploratory analysis investigated the effect of race on the clinical outcome of combined androgen blockade (CAB). METHODS: Data for analysis were obtained from a double-blind, randomized, multicenter trial comparing CAB in the form of bicalutamide (50 mg once daily) or flutamide (250 mg three times daily) plus luteinizing hormone-releasing hormone analogs (LHRHa; goserelin acetate 3.6 mg, or leuprolide acetate 7.5 mg) in 813 patients with stage D(2) prostate cancer (median follow-up, 160 weeks). Patients were analyzed according to race (African American [AA], white, or other). The primary clinical events were disease progression and survival. RESULTS: Four hundred and four patients received bicalutamide/LHRHa and 409 received flutamide/LHRHa. Although treatment with bicalutamide/LHRHa resulted in slightly longer time to progression and survival time in white and AA males than treatment with flutamide/LHRHa, the differences between the treatment groups were not statistically significant. CONCLUSIONS: No marked effect of race on clinical outcome was observed regardless of antiandrogen, suggesting that similar treatment benefits are to be expected in either race.

Adenocarcinoma↗
PubMed1999

Conservative surgical therapy for penile and urethral carcinoma.

OBJECTIVES: Invasive penile and urethral tumors are traditionally treated with aggressive excision that requires involved organ and adjacent organ sacrifice. An alternative approach seeks to completely excise the tumor with adequate margins while preserving form and function of the organ. We present 6 patients who underwent such organ-sparing surgery. METHODS: Six selected cases (4 penile and 2 urethral) are presented with operative photographs and pertinent data. RESULTS: Three distal tumors of the penis were treated with excision limited to the glans with histopathologic findings of verrucous carcinoma, melanoma, and angiosarcoma. One patient with squamous cell carcinoma of the distal shaft refused partial penectomy and underwent a local wedge resection. A patient with locally advanced bulbourethral transitional cell carcinoma (TCC) refused cystourethrectomy and underwent an anterior urethrectomy and perineal urethrostomy. A 48-year-old woman with an adenocarcinoma contained in a very distal urethral diverticulum underwent simple diverticulectomy and excision of distal urethra. Postoperative voiding and sexual function were well preserved. Follow-up was 12 to 48 months. The patient with angiosarcoma died of lung metastases at 48 months with no local disease, and the patient with bulbourethral TCC developed pelvic disease at 12 months with no local recurrence and died of metastases at 25 months. CONCLUSIONS: Organ-sparing surgery is appropriate in selected patients on the basis of stage and location, high risk of distant failure, and patient disposition. Close follow-up is necessary. Comanagement with reconstructive and oncologic specialists optimizes results and outcomes.

Adult↗
PubMed1999

Does long-term finasteride therapy affect the histologic features of benign prostatic tissue and prostate cancer on needle biopsy? PLESS Study Group. Proscar Long-Term Efficacy and Safety Study.

OBJECTIVES: Finasteride, a common agent used to treat benign prostatic hyperplasia (BPH), inhibits 5-alpha-reductase. Testosterone is converted by 5-alpha-reductase to the more potent dihydrotestosterone, which is the primary androgen in the prostate. Leuprolide is a stronger antiandrogen that is used to downstage prostate cancer before radical prostatectomy. Leuprolide induces marked atrophy of prostate carcinoma cells, which sometimes makes pathologic diagnosis of cancer difficult, although evaluation at radical prostatectomy is easier than at biopsy. It is unknown whether finasteride produces similar changes, which would result in greater diagnostic difficulty because such changes would be seen on biopsy to rule out cancer in men with suspicious clinical findings treated for BPH. The current study investigated the histologic effects of finasteride therapy on human prostate cancer and benign prostatic tissue on needle biopsy. METHODS: In blinded manner, we reviewed 53 needle biopsy specimens showing prostate carcinoma (35 treated with finasteride, 18 with placebo). Also reviewed in blinded manner were 50 benign needle biopsy specimens (25 treated with finasteride, 25 with placebo). The Gleason score, number of cores involved, percentage cancer involvement in a core, percentage of atrophic changes in cancer cells, presence of mitoses, blue-tinged mucinous secretions, prominent nucleoli, and high-grade prostatic intraepithelial neoplasia were documented for each case in the cancer group. The percentage of atrophy, basal cell hyperplasia, transitional metaplasia, chronic inflammation, and stromal proliferation was documented for each case in the benign group. RESULTS: No significant histologic differences were present in either the benign or cancer group between cases treated with finasteride and placebo. CONCLUSIONS: We conclude that finasteride treatment for BPH does not cause difficulty in the diagnosis of cancer in prostate needle specimens. It is possible that there are severely atrophic areas resulting from finasteride treatment that are undersampled. However, the conclusion that cancer seen on needle biopsy in men treated with finasteride is unaltered and readily identified as cancer remains valid.

Aged↗
PubMed1999

Comparative quality-of-life analysis after radical prostatectomy or external beam radiation for localized prostate cancer.

OBJECTIVES: To determine and compare quality-of-life (QOL) evaluations from patients who received external beam radiation therapy or radical prostatectomy for the treatment of localized prostate cancer, and to compare differences in QOL assessments for urinary and sexual function after radical prostatectomy as reported by patient and physician. METHODS: Two hundred three patients treated by radical prostatectomy and 257 patients treated by external beam irradiation, all beyond 12-month follow-up after therapy, responded to a QOL questionnaire. The difference in responses with regard to bladder, bowel, and sexual function, overall satisfaction with treatment, and choice of the same treatment were assessed. Satisfaction with and choice of the same treatment were also specifically assessed according to bowel and bladder function and current disease status. The medical records of patients treated by radical prostatectomy were reviewed by an independent data manager to record the physician's assessment of continence and sexual function for comparison with that patient's assessment as noted in the questionnaire. RESULTS: Problems with urinary continence were more frequent among patients treated by radical prostatectomy; problems with gastrointestinal function were more frequent after irradiation. Sexual dysfunction was similar in both groups, although surgical patients experienced a greater impact on sexual relationships. The physician estimates of urinary continence were more favorable than the patient-reported outcomes. However, the physician estimate of sexual function closely approximated that of the patient. Preservation of sexual function among patients who underwent nerve-sparing surgery was disappointingly low. Only for the response to the question dealing with difficulty in achieving an erection was there a statistically significant benefit for patients receiving nerve-sparing versus non-nerve-sparing procedures. Patient satisfaction with and choice of the same treatment varied according to function and current disease status. Patients who had incontinence or bowel dysfunction or had evidence of recurrent disease were statistically less likely to choose the same treatment again when compared with functional and disease-free counterparts. Because irradiated patients were on average 6 years older than surgical patients, responses were adjusted for age; adjustment for age did not alter results. CONCLUSIONS: QOL is determined by the treatment received, by the assessment source, and by the patient's function and disease status at the time of assessment. Prospective and longitudinal studies will more accurately quantify immediate and chronic alterations in QOL. Uniformity of evaluation through consolidation of QOL instruments will permit more accurate cross-series and cross-treatment comparisons.

Adult↗
PubMed1999

Proteinchip(R) surface enhanced laser desorption/ionization (SELDI) mass spectrometry: a novel protein biochip technology for detection of prostate cancer biomarkers in complex protein mixtures.

Improving early detection, diagnosis, treatment monitoring and prognosis of cancer will require rapid and high throughput detection, identification, and measurement of multiple biomarkers. In this study, we demonstrate the versatility of the innovative SELDI ProteinChip(R) MS technology for the rapid, reproducible and simultaneous identification of four well-characterized prostate cancer-associated (PCA) biomarkers, prostate specific antigen (free and complexed forms), prostate specific peptide, prostate acid phophatase and prostate specific membrane antigen in cell lysates, serum and seminal plasma. Proteins corresponding to the mass of these biomarkers could readily be captured and detected using either chemically defined or antibody coated ProteinChip(R) arrays. Several (yet to be identified) proteins were found upregulated in cell lysates of pure populations of PCA cells procured by laser capture microdissection (LCM) when compared with mass spectra of normal cell lysates. Coupling LCM with SELDI provides tremendous opportunities to discover and identify the signature proteins associated with each stage of tumor development. Collectively, these observations demonstrate the potential of SELDI for the discovery and simultaneous detection of and clinical assay development for PCA biomarkers in complex biological mixtures.

Journal Article↗
PubMed1999

Endocrine effects, efficacy and tolerability of a 10.8-mg depot formulation of goserelin acetate administered every 13 weeks to patients with advanced prostate cancer.

OBJECTIVE: To determine the endocrine effects, efficacy and tolerability of a 10.8-mg depot formulation of Zoladextrade mark (goserelin acetate, Zeneca Pharmaceuticals, Wilmington, Delaware, USA), a luteinizing hormone-releasing hormone agonist analogue, when administration was extended from every 12 weeks to every 13 weeks in patients with advanced prostate cancer. PATIENTS AND METHODS: Between July 1995 and May 1996, 59 patients with either locally advanced (T3 or T4) or metastatic prostate cancer were enrolled in an open-label, multicentre trial. Primary efficacy endpoints were testosterone measurements, and assessments of prostate specific antigen (PSA) response, subjective and objective response. Quality of life (QoL) was a secondary efficacy endpoint. RESULTS: Mean testosterone concentrations decreased to < 0.3 microgram/L by week 4 and remained so for the duration of treatment. There were no statistically significant differences in mean testosterone levels between weeks 12 and 13, or weeks 25 and 26. Serum testosterone suppression was adequate in all 58 evaluable patients at week 13, and 51 of 52 (98%) patients at week 26. Of the 58 evaluable patients, 52 (90%) had a PSA response. A subjective response was recorded for six of 11 evaluable patients. Of 58 patients evaluable for objective response, 46 (79%) had a partial response, three (5%) had stable disease and nine (16%) had objective progression. Except for a significant (P=0.014) decrease in overall sexual interest, QoL was unchanged during therapy. The most common side-effects, regardless of causality, were hot flushes (67%), pain (31%) and pelvic pain (22%). Mild injection-site complaints occurred with only three of 221 (1.4%) depot injections. CONCLUSIONS: Zoladextrade mark 10.8-mg depot, administered every 13 weeks to patients with advanced prostatic cancer, is well tolerated, provides adequate suppression of serum testosterone and produces PSA, subjective and objective responses.

Aged↗
PubMed1999

The durability of external beam radiation therapy for prostate cancer: can it be identified?

PURPOSE: We establish criteria to identify a durable response to external beam radiation therapy by calculation of biochemical progression-free probability for patients who attained and maintained defined nadir prostate specific antigen (PSA) levels more than 5 years after treatment. MATERIALS AND METHODS: A total of 460 patients were treated with external beam radiation monotherapy from 1976 to 1995. Patients with PSA less than 0.5 (group 1) or 0.5 to 1.0 (group 2) ng./ml. more than 5 years after treatment were identified. Treatment failure was defined as 3 consecutive increases in PSA after nadir. Progression-free probability after 60 months was calculated for each group. A comparison was also made to patients achieving the same nadir levels anytime after treatment. RESULTS: Failure occurred at 133 months in 1 of 26 group 1 patients (4%) and at a median of 76 months in 5 of 26 group 2 patients (19%). At 10 years progression-free probability was 91% for group 1 compared to 72% for group 2 (p = 0.0575). These same nadir levels anytime after treatment were associated with higher failure rates of 55% for group 1 and 72% for group 2. CONCLUSIONS: If a PSA nadir of less than 0.5 ng./ml. was maintained 5 years after therapy, subsequent failure was rare. Although statistical significance was not reached (p = 0.0575), a higher failure rate was noted if the nadir PSA was 0.5 to 1.0 ng./ml. at 5 years. Thus, patients with PSA 0.5 to 1.0 ng./ml. require careful continued surveillance. Nadir levels less than 1.0 ng./ml. anytime before 5 years were associated with a substantial risk of subsequent progression.

Disease Progression↗
PubMed1999

Consensus statements on radiation therapy of prostate cancer: guidelines for prostate re-biopsy after radiation and for radiation therapy with rising prostate-specific antigen levels after radical prostatectomy. American Society for Therapeutic Radiology and Oncology Consensus Panel.

PURPOSE: To develop evidence-based guidelines for (1) prostate re-biopsy after radiation and (2) radiation therapy with rising prostate-specific antigen (PSA) levels after radical prostatectomy in the management of patients with localized prostatic cancer. DESIGN: The American Society of Therapeutic Radiology and Oncology (ASTRO) challenged a multidisciplinary consensus panel to address consensus on specific issues in each of the two topics. Four well-analyzed patient data sets were presented for review and questioning by the panel. The panel sought criteria that would be valid for patients in standard clinical practice as well as for patients enrolled in clinical trials. Subsequent to an executive session that followed these presentations, the panel presented its consensus guidelines. RESULTS AND CONCLUSIONS: Based on the data presented, the prostate re-biopsy negative rates ranged from 62% to 80% for patients with stage T1-2 tumors. The panel judged that prostate re-biopsy is not necessary as standard follow-up care and that the absence of a rising PSA level after radiation therapy is the most rigorous end point of total tumor eradication. Further, the panel judged that re-biopsy may be an important research tool. Based on the data presented, the long-term (5 years or more) PSA remission rate after salvage radiation therapy ranges from 27% to 45%. The panel requested results from prospective randomized trials to evaluate optimally this information. The panel judged that the total dose of radiation should be 64 Gy or slightly higher and that, in patients with or without radiation therapy, there is no standard role for androgen suppressant therapy for rising PSA values after prostatectomy.

Biopsy↗
PubMed1999

Prostate-specific membrane antigen levels in sera from healthy men and patients with benign prostate hyperplasia or prostate cancer.

Prostate-specific membrane antigen (PSMA) serum levels have been proposed to be of prognostic significance in patients with advanced prostate disease. The objective of the present study was to confirm PSMA serum expression by Western blot techniques, to determine whether such data could assist in the differentiation of benign from malignant prostatic disease, and to determine the suitability of serum PSMA measurements in predicting recurrent or progressive prostate malignancies. We measured PSMA, a transmembrane glycoprotein identified in prostate epithelial cells, in the sera of 236 normal individuals and cancer patients by Western blot analysis. Within the normal male population, PSMA levels increase with age and were found to be significantly elevated in subjects more than 50 years of age when compared to those of younger men. We did not confirm previous reports that serum PSMA measurements could distinguish late-stage prostate carcinoma from early-stage prostate carcinoma, nor did we find PSMA to be more effective than prostate-specific antigen in monitoring prostate cancer patient prognosis. Furthermore, we found elevated serum PSMA in healthy females, and, similar to the healthy male population, the levels increased with age, with the highest levels found in the sera from breast cancer patients. These latter observations further support that PSMA is not a specific biomarker for prostate cancer and that a variety of normal and diseased tissue may contribute to the serum levels of PSMA.

Adult↗
PubMed1998

Involvement of Shc in the signaling response of human prostate tumor cell lines to epidermal growth factor.

Autocrine growth factors for the epidermal growth factor receptor (EGFR) have been identified in prostate tumors, implicating a role for EGFR in the progression of prostate cancer. To investigate early signaling mechanisms used by the EGFR in prostate tumor cells, we have characterized the involvement of the Shc (src homology 2/x-collagen related) adapter protein in EGFR signaling in several human prostate tumor cell lines. In androgen-responsive lymph node-prostate cancer (LNCaP) cells and androgen-insensitive PC3, DU145 and PPC-I cells, Shc was identified as one of the most prominent phosphotyrosine proteins to be elevated in response to EGF. Equivalent levels of the 46- and 52-kDa Shc isoforms were detected in all of the tumor cell lines tested. However, levels of the 66-kDa isoform were variable among the cell lines. In all of the tumor cell lines, EGF caused an association between Shc and Grb2, another adapter protein linked to cellular ras activation. Additionally, several phosphotyrosine proteins, including a 115-120-kDa protein in EGF-treated LNCaP cells, co-associated with Shc. The profile of these Shc-associating proteins, however, differed among the tumor cell lines. Our results indicate that Shc is a common downstream element of EGFR signaling in prostate tumor cells and suggest multiple functions for Shc in prostate tumorigenesis.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Comparison of goserelin and leuprolide in combined androgen blockade therapy.

OBJECTIVES: To perform exploratory analyses of data from a controlled trial that assessed the efficacy and tolerability of two antiandrogens, bicalutamide and flutamide, each combined with monthly depot preparations of leuprolide or goserelin, in patients with Stage D2 prostate cancer. One analysis compared goserelin plus antiandrogen therapy with leuprolide plus antiandrogen therapy; a second analysis compared the four combined androgen blockade (CAB) regimens. METHODS: This was a randomized, multicenter trial, open-label for luteinizing hormone releasing hormone analogue (LHRH-A) therapy, double-blind for antiandrogen therapy, with a two-by-two factorial design. Eight-hundred thirteen patients were allocated in a ratio of 2:1 to goserelin therapy (3.6 mg every 28 days) or leuprolide therapy (7.5 mg every 28 days) and 1:1 to bicalutamide therapy (50 mg once a day) or flutamide therapy (250 mg three times a day). The end points of time to progression and survival were assessed with a median of 160 weeks of follow-up. RESULTS: The percentages of progression events (70.9% versus 73.3%) and deaths (54.3% versus 56.8%) were similar for goserelin plus antiandrogen and leuprolide plus antiandrogen therapies. The hazard ratios for goserelin plus antiandrogen therapy to leuprolide plus antiandrogen therapy were 0.99 (95% confidence interval [CI] 0.84 to 1.18; P = 0.92) and 0.91 (95% CI 0.75 to 1.11; P = 0.34) for time to progression and survival, respectively. Goserelin plus antiandrogen and leuprolide plus antiandrogen therapies were generally well tolerated, and the side effects associated with depot administration occurred with a low frequency in the two groups. There were no significant differences among the goserelin plus bicalutamide, goserelin plus flutamide, or leuprolide plus bicalutamide therapy groups, but leuprolide plus flutamide therapy had a significantly poorer outcome than the other three therapies. The side-effect profiles for the four CAB groups were generally similar; diarrhea was more common among patients treated with flutamide and hematuria was more common among patients treated with bicalutamide. CONCLUSIONS: Although the results of these exploratory analyses should be interpreted with caution, they indicate that goserelin plus antiandrogen and leuprolide plus antiandrogen therapies are similarly well tolerated and have equivalent time to progression and survival, and that leuprolide plus flutamide therapy appears to be the least effective of the four CAB regimens.

Adult↗
PubMed1998

Percent free prostate-specific antigen values in men with recurrent prostate cancer after radical prostatectomy.

OBJECTIVES: Patients with prostate cancer may have more of the complexed form of prostate-specific antigen (PSA) in the serum, whereas patients with benign prostatic hyperplasia have less of this complexed form and thus a higher proportion of the free form. However, the molecular basis for the lower percent of free PSA in patients with prostate cancer remains unknown, and considerable overlap in values exists. We examined this hypothesis in men with recurrent or persistent cancer after radical prostatectomy. These men, who have "pure" cancer in that they have no benign elements to their disease, should have very low percent free PSA values. METHODS: Forty-six men with recurrent (persistent) cancer as manifested by rising PSA values (mean [+/-SD] 2.4 +/- 2.5 ng/mL) after radical prostatectomy were available for analysis. Specimens were analyzed with the use of the Abbott AxSYM free and total PSA assays. The Mann-Whitney U test was used to compare percent free PSA values in this recurrent cancer group with values from a previously defined population of 413 men (225 with benign disease and 188 with prostate cancer before prostatectomy). RESULTS: Median values of percent free PSA in the recurrent cancer group (8.4%) were significantly lower than values in the preoperative cancer (11.7%) or benign (17.4%) groups (P < 0.0001 for both comparisons). Among patients in the "pure" cancer group, 30 (65%) had values less than 10%; however, 4 patients (9%) had values from 1 5% to 1 9%, and another 4 (9%) had values of 20% or greater. Pathologically, patients with higher values (15% or greater) had aggressive disease. All patients with values of 20% or greater had evidence of seminal vesicle involvement or nodal disease. CONCLUSIONS: Although most cancers exhibit low values of percent free PSA, a significant proportion of aggressive tumors will demonstrate high values. Until this latter phenomenon can be explained, the widespread use of percent free PSA to distinguish benign from malignant disease or to stage confirmed malignant disease should be approached with caution.

Humans↗