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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostate cancer is unique among the potentially lethal human malignancies in the wide discrepancy between the high prevalence of histologic changes recognizable as cancer and the much lower prevalence of the clinical disease. Despite the availability of effective tests for early detection and of effective treatment for cancers so detected, the diagnosis usually is not established until the tumor is locally advanced or metastatic. Yet, physicians hesitate to use these tests for fear that many cancers found would be latent, of little threat to the life or health of the host, and treatment could introduce inappropriate morbidity. Latent or "clinically unimportant" cancers can be distinguished from those that are clinically important by the larger volume, higher grade, and greater invasiveness of the latter. The available tests can detect only those cancers large enough to be palpable, visible on ultrasound, or capable of elevating the serum level of prostate-specific antigen. Such cancers are clinically important and should be treated for cure if the life expectancy of the patient is sufficiently long and the morbidity rate of therapy is low. Early detection of prostate cancer using the tests that are available today may widen the window of opportunity so that treatment indeed becomes possible in those for whom it is necessary.
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PMID:Early detection of prostate cancer. 137 77

OBJECTIVE--To identify the effect of digital rectal examination (DRE) on serum prostate-specific antigen (PSA) levels. DESIGN--A prospective trial before and after DRE. SETTING--Multicenter outpatient screening program. PATIENTS--A total of 2754 healthy men aged 40 years and older who presented to a prostate cancer screening program and consented to two phlebotomies. MAIN OUTCOME MEASURE--Changes in serum PSA levels after DRE. RESULTS--Patients were divided into four groups based on their initial serum PSA levels. The levels were chosen based on previous studies that showed different incidences of prostate cancer within these groups. The two groups with the lowest initial PSA values (0.1 through 4 micrograms/L and 4.1 through 10 micrograms/L) were found to have statistically insignificant changes in the serum PSA levels after DRE. The group with initial PSA levels of 10.1 through 20 micrograms/L had increases in serum PSA values that showed a trend toward statistical significance. The group with initial PSA levels of greater than 20 micrograms/L had statistically significant increases in serum PSA values after DRE. The alterations in serum PSA levels in the two groups with the highest PSA values were not clinically important as the patients' clinical treatment was not altered. CONCLUSIONS--No clinically important effects on serum PSA levels were noted after DRE.
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PMID:The effect of digital rectal examination on prostate-specific antigen levels. 137 45

Detection of persistent or recurrent prostate cancer by digital rectal examination (DRE) after definitive radiotherapy is difficult. With the availability of transrectal ultrasonography (TRUS), the detection of prostate cancer has improved substantially. Since 1987 we have used TRUS to evaluate the prostate after definitive radiotherapy. A hypoechoic lesion suggestive of cancer was identified in 45 of 56 patients (80%) studied. Sonographically directed transrectal needle biopsies were performed in 27 of these (60%), and 16 (59%) were positive for cancer. The presence of a palpable nodule suggestive of cancer (present in 7 patients) was not predictive of a positive biopsy specimen. In 14 patients ultrasound-guided and digitally-guided biopsies were performed at the same time; 8 (57%) of the ultrasound-guided biopsy specimens were positive compared with only 4 (29%) of the digitally-guided biopsy specimens. In all 7 patients with an elevated serum level of prostate-specific antigen (PSA) an ultrasound-guided biopsy result was positive. Random biopsies of sonographically normal (isoechoic) areas of the prostate were performed in 8 patients, but only 2 specimens (25%) were positive for cancer. Ultrasound-guided transrectal biopsy of hypoechoic lesions was a safe and effective technique for identifying residual cancer in the irradiated prostate, regardless of the palpable findings. In the presence of an elevated PSA level, such biopsies invariably identified residual cancer. The use of TRUS, ultrasound-guided biopsy, and the measurement of PSA, in addition to DRE, may aid in the detection of residual cancer after definitive radiotherapy.
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PMID:Detection of residual prostate cancer after radiotherapy by sonographically guided needle biopsy. 137 15

The potential prognostic significance of prostate-specific antigen (PSA) serum concentrations was evaluated in 171 patients with stages A2 to C adenocarcinoma of the prostate treated with external beam radiotherapy. After a median follow-up of 17 months, 12 patients sustained relapse of disease and PSA levels were found to be prognostically significant in three ways. (a) Pretreatment PSA level: none of 59 patients with a pretreatment PSA level less than or equal to 4 ng/ml relapsed to date and only one developed a subsequently rising PSA profile; 7 of 102 patients (7%) with a pretreatment PSA level in the range 4-40 ng/ml relapsed and 17 (17%) showed a rising PSA profile; 5 of 10 patients (50%) with a pretreatment PSA level greater than or equal to 40 ng/ml relapsed and six (60%) developed rising PSA values. The differences were significant and were maintained when patients were stratified by stage or grade. (b) PSA level at 6 months: for patients with pretreatment PSA levels in the range 4-40 ng/ml, a 6-month value greater than 2 ng/ml predicted a significantly worse outcome than a 6-month value less than 2 ng/ml. (c) Rising post-treatment PSA values: following a radiation-related nadir in PSA levels, 24 patients experienced rising PSA values and 8 (33%) relapsed at a median time of 5 months after onset of the rising values--a significantly higher relapse rate than observed in patients with non-rising PSA values. Whether the majority, or all, of the patients with rising PSA levels relapse, requires further follow-up. In conclusion, serum PSA levels are strong prognostic determinants of outcome following radiotherapy for prostate cancer and appear to add prognostic information independently of tumor stage and grade.
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PMID:Prostate-specific antigen as a prognostic factor for prostate cancer treated by external beam radiotherapy. 137 65

We describe a modification of the Yang Pros-check radioimmunoassay for prostate-specific antigen (PSA) that increases the analytical sensitivity of the assay approximately threefold (from a working range of 0.3-50 to 0.1-1.2 micrograms/L). It can detect PSA added to zero-concentration diluent (bovine serum albumin solution) at 0.10 microgram/L or added to zero-concentration control female serum at 0.20 microgram/L (P less than 0.05). In 26 patients tested after cystoprostatectomy for bladder cancer (who had normal prostates without cancer on histologic examination), PSA values by this ultrasensitive assay were all less than 0.10 microgram/L. Therefore, we propose this value as the upper limit of the 95% reference interval. In a retrospective study of two patients who developed recurrent prostate cancer, serum PSA values increased above the 0.1 microgram/L detection limit 175 and 581 days before increasing above the 0.3 microgram/L detection limit of the standard Yang assay. This ultrasensitive radioimmunoassay of PSA should prove more useful than current methods for detecting early recurrence of prostate cancer.
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PMID:Ultrasensitive radioimmunoassay of prostate-specific antigen. 137 91

The sensitivity and specificity of prostate-specific antigen (PSA) in prostatic carcinoma is of considerable interest. In this study, we have assessed PSA and also correlations between positive and negative predictive values of PSA and the prevalence of prostatic cancer. Firstly, cutoff point must be selected as a positivity criterion for prostatic cancer, according to the purpose of the test. Besides sensitivity, all the other operating characteristics are dependent upon the prevalence of the disease. Specificity and positive predictive value increase while negative predictive value decreases when prevalence increases. As the relationship between the age and the prevalence of prostatic carcinoma is well known, the age of the patient becomes a variable of prominent importance when assessing the test.
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PMID:Prostate-specific antigen test: operating characteristics and assessment criteria in the diagnosis of prostatic cancer. 137 76

Carcinoma of the prostate is the most commonly diagnosed cancer in men. The natural history and the biological aggressiveness are primarily determined by tumor volume. At the time of diagnosis, only one third of all tumors are pathologically confined to the prostate and eligible for curative therapy. Early detection by the general practitioner with prostate-specific antigen and digital rectal examination should be the primary goal. Currently, diagnosis is best established by transrectal ultrasound-guided biopsies. For the treatment of localized prostate cancer, men who undergo radical retropubic prostatectomy have been shown to have superior long-term results when compared to those who have received radiation therapy. With an improved understanding of the prostatic anatomy and nerve-sparing surgical techniques, morbidity from impotence and incontinence are minimal. In advanced carcinoma, 70 to 80% of men initially respond well to androgen withdrawal. Unfortunately, androgen-independent cells will continue to multiply, leading to tumor progression and death. Until effective chemotherapeutic agents are developed, we can only achieve palliation in advanced disease.
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PMID:[Prostate carcinoma--a current review]. 137 72

Prostate growth curves were estimated from serial prostate-specific antigen (PSA) measurements on frozen sera in three groups of men: (a) 16 men with no prostatic disease by urological history and examination; (b) 20 men with a histological diagnosis of benign prostatic hyperplasia (BPH) who had undergone simple prostatectomy; and (c) 18 men with a histological diagnosis of prostate cancer. The median number of repeated PSA measurements over an 8- to 26-yr period prior to histological diagnosis or exclusion of prostate disease was eight and 11 for noncancer and cancer subjects, respectively. Predicted rates of change in PSA (PSA velocity) were linear and curvilinear for control and BPH subjects, respectively. Subjects with cancer demonstrated both a linear and an exponential phase of PSA velocity. Based on time to double PSA, we estimated the epithelial doubling time for men without prostate disease to range from 54 +/- 13 yr at age 40 to 84 +/- 13 yr at age 70. For men with BPH, doubling times ranged from 2 +/- 13 yr at age 40 to 17 +/- 5 yr at age 85. Subjects with local/regional and advanced/metastatic cancer had similar PSA doubling times of 2.4 +/- 0.6 yr and 1.8 +/- 0.2 yr, respectively. These data are consistent with what is known about prostatic growth with age in men without prostate disease and BPH, and the kinetics of prostate cancer growth. Estimates of prostatic growth rate from changes in PSA may be useful clinically in management of men with prostate disease.
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PMID:Estimation of prostatic growth using serial prostate-specific antigen measurements in men with and without prostate disease. 137 67

Using gene-specific synthetic oligonucleotides the expression and regulation of kallikrein-like genes in the human prostatic cancer cell line LNCaP were studied. Prostate-specific antigen (PSA) and human glandular kallikrein (hGK-1) together constitute a subfamily of serine proteases exclusively produced in the human prostate. RNA analysis revealed that both genes are expressed in LNCaP cells with PSA basal levels being 2-fold higher than hGK-1 levels. Both mRNAs are induced over a period of 24 h in the presence of 3.3 nM of the synthetic androgen mibolerone. Stimulation of PSA RNA is about 5-fold, whereas hGK-1 stimulation is less pronounced. Nuclear run-on analysis revealed that androgen induction of kallikrein-like genes in LNCaP cells is a rapid event (less than 3 h) occurring at the level of transcription initiation. Treatment of cells with cycloheximide demonstrates that, while PSA/hGK-1 basal transcription strictly depends on continuous protein synthesis, transcriptional induction by androgen does not. This suggests the direct involvement of the androgen receptor in the induction process independent of additional labile protein factors necessary for kallikrein basal transcription. A binding motif is present in the PSA and hGK-1 promoters, closely resembling the consensus sequence for steroid-responsive elements. The androgen antagonist cyproterone acetate was also able to stimulate transcription of kallikrein-like genes in LNCaP cells. In contrast, androgen-dependent transcriptional suppression of the protooncogene c-myc was strongly counteracted by cyproterone acetate. Thus, antiandrogens act differentially on androgen-regulated prostate-specific (PSA, hGK-1) and growth-related (c-myc) gene expression in LNCaP cells.
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PMID:Transcriptional regulation of prostate kallikrein-like genes by androgen. 137 10

The biochemical markers alkaline phosphatase (Alk P), prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA) were measured 3-monthly in 61 patients with disseminated prostatic cancer who were treated with LHRH analogues. The decrease in Alk P and PSA during the first 6 months of treatment was significantly related to a better survival. In this follow-up study, only PSA was useful for monitoring prostatic cancer during hormonal treatment. Before it was visible on a bone scan, PSA gave an indication of tumor progression. PSA might permit omission of routine bone scanning. Consensus must be obtained about the cost-saving use of biochemical markers in the treatment of disseminated prostatic cancer. With the number of treatment options increasing, objective measures are of utmost importance. Biochemical markers can be used for prognosis and monitoring of the treatment of patients with disseminated prostatic cancer.
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PMID:Value of biochemical markers in the management of disseminated prostatic cancer. 137 92


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