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

The preliminary data we present in this report suggest that the ratio of polyclonal-monoclonal serum prostate-specific antigen levels may add clinically useful information to that obtained using serum prostate-specific antigen levels alone. We hypothesize that the diversity of prostate-specific antigen ratios observed in our data reflects a diversity in the antigenic and structural attributes of prostate-specific antigen molecules found in the sera of patients with prostate cancer. Further, this heterogeneity of molecules is a reflection of the diverse and altered metabolic state of human prostate cancer and appears to be related to biologic behavior in individual patients.
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PMID:Ratio of polyclonal-monoclonal prostate-specific antigen levels. Discrimination of nodal status in prostate tumors that produce low marker levels. 171 3

The success of a screening programme for cancer depends on the sensitivity of the tests used and on the proportion of the target population that comes forward for screening. To assess the value of digital rectal screening and prostate-specific antigen (PSA) measurement as screening measures, the 814 men in a city general practice aged between 55 and 70 were recruited in one of five different ways. Men with a palpably suspicious prostate or a serum PSA greater than 4 ng/ml were referred for transrectal ultrasonography and, if indicated, biopsy. 472 men (58%) were screened; of these 68 underwent transrectal ultrasonography and 29 biopsy. In 7 the biopsy specimen showed carcinoma. Serum PSA was better than digital examination as a screening test--all men with prostate cancer had raised concentrations of serum PSA, whereas only 1 had a palpably abnormal prostate. All 7 had localised disease, and 5 underwent radical prostatectomy. The best methods of patient recruitment were to send an appointment for screening and to "tag" the patient's notes.
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PMID:Pilot study of screening for prostate cancer in general practice. 171 3

Preoperative serum prostate-specific antigen (PSA) was measured in 63 men who had clinically localized, previously untreated adenocarcinoma of the prostate and underwent subsequent radical prostatectomy and bilateral pelvic lymph node dissection. Pathologic stage and grade were correlated to the serum PSA value. Patients with organ-confined (P1, P2) and extracapsular (P3, P3N +) prostate cancer had elevated preoperative serum PSA levels (greater than 4 ng/mL) in 61 and 90 percent of cases, respectively. Patients with low-grade and high-grade tumor histology had elevated preoperative PSA levels in 62 and 80 percent of cases, respectively. In distinguishing between organ-confined and extracapsular disease with a preoperative serum PSA of 10 ng/mL as a cutoff value, the sensitivity was 68 percent, the specificity was 66 percent, the positive predictive value was 46 percent, and the negative predictive value was 83 percent. Although there was a trend of increasing preoperative serum PSA levels with higher pathologic stage or grade, there was no significant difference in preoperative serum PSA values with pathologic stage and/or grade considered as a group or in determining stage and/or grade preoperatively on an individual basis.
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PMID:Preoperative prostate-specific antigen in predicting pathologic stage and grade after radical prostatectomy. 171 21

The American Cancer Society recommends annual digital rectal examination for men over forty years of age. We evaluated 414 men between forty and fifty-nine years of age with a questionnaire, digital rectal examination (DRE), and prostate-specific antigen (PSA) determination. One hundred ninety were forty to forty-nine years old, and 224 were fifty to fifty-nine years old. Four patients in the forty to forty-nine age group had elevated PSA determinations, and 7 had abnormal findings on DRE. Using prostate ultrasound and biopsy, no cases of prostate cancer were diagnosed. Ten patients in the fifty to fifty-nine age group had elevated PSA determinations, and 5 were diagnosed to have prostate cancer. These data suggest that PSA may have utility in detecting cancer in younger men.
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PMID:Prostate cancer screening in younger men: prostate-specific antigen and public awareness. 171 22

Immunologic measurements of the serum concentration of prostate-specific antigen (PSA), an abundant prostatic-secreted serine proteinase, are frequently used to monitor patients with prostate cancer, though it has not been ascertained whether this immunoreactivity represents a PSA zymogen, the active proteinase, or PSA complexed to extracellular proteinase inhibitors. To characterize the PSA immunoreactivity in serum, we used monoclonal antibodies produced against PSA and a polyclonal rabbit IgG against alpha 1-antichymotrypsin in the design of three noncompetitive PSA assays: assay T, which detected PSA both when present as the active proteinase and when complexed to alpha 1-antichymotrypsin; assay F, which recognized the active proteinase but most poorly detected PSA complexed to alpha 1-antichymotrypsin; and assay C, which was specific for PSA complexed to alpha 1-antichymotrypsin. We used the three assays to measure PSA immunoreactivity in 64 patients' sera and in the effluent after gel chromatography of sera from four patients. This identified an 80- to 90-kDa complex between PSA and alpha 1-antichymotrypsin as the predominant fraction of the PSA immunoreactivity in blood plasma; an immunoreactive 25- to 40-kDa compound was the minor fraction.
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PMID:Prostate-specific antigen in serum occurs predominantly in complex with alpha 1-antichymotrypsin. 2094 Mar 31

The authors reviewed the results and relationship of prebiopsy prostate-specific antigen (PSA) assay, digital rectal examination (DRE), and transrectal ultrasound (TRUS) in 124 consecutive patients who underwent a prostate biopsy because of abnormal results of either DRE or TRUS. Results of the three tests (PSA, DRE, and TRUS) showed abnormalities in 54%, 75%, and 84.6% of patients, respectively; biopsy results were positive for cancer in 45.2%. Cancer detection rate increased as the PSA value increased from less than or equal to 4 ng/ml (17.5%) to more than 4 ng/ml (68.7%) to more than 20 ng/ml (83.3%), and as the number of positive tests increased (6.9% for one, 32.7% for two, and 82.6% for three). The PSA assay was the most important parameter of the diagnostic triad. These results suggested that regardless of DRE and TRUS findings, PSA less than or equal to 4 ng/ml confers a low prostate cancer risk, PSA more than 4 ng/ml but less than or equal to 10 ng/ml confers an intermediate prostate cancer risk, and PSA more than 10 ng/ml confers a high prostate cancer risk. Regardless of other findings, all patients with a PSA value more than 10 ng/ml require biopsy because of the high likelihood of cancer. All patients with abnormal DRE or TRUS results still require biopsy despite a low index of suspicion of prostate cancer when the PSA value is less than or equal to 4 ng/ml.
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PMID:The role of prostate-specific antigen as part of the diagnostic triad and as a guide when to perform a biopsy. 171 34

Serum prostatic acid phosphatase (PAP), gamma-seminoprotein (gamma-Sm), and prostate-specific antigen (PA) levels were measured in 63 untreated patients with prostatic cancer. The sensitivities of PAP, gamma-Sm, and PA as markers of malignancy were 68%, 83%, and 77%, respectively. The latter two markers were more sensitive than PAP, especially in stage B disease. The specificities of PAP, gamma-Sm, and PA were 95%, 93%, and 93%, respectively. Patients with multiple positive markers were very likely to have prostatic cancer. In reactivation of the disease, positive rates for gamma-Sm and PA were higher than for PAP, indicating that the former two markers are more reliable for monitoring prostatic cancer.
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PMID:Multiple marker evaluation in prostatic cancer with prostatic acid phosphatase, gamma-seminoprotein and prostate-specific antigen. 171 22

Three hundred and ninety eight self-referred men with no histories of prostate problems were followed once each year for up to four years to determine the feasibility of early prostate cancer detection by digital rectal examination, transrectal ultrasound, and prostate-specific antigen. Evaluation of prostate-specific antigen was based on a polyclonal level of normal of 2.6 nanograms per milliliter by the Yang assay. Biopsies were performed when indicated by either transrectal ultrasound or digital rectal examination. The overall cancer detection rate for the four year period was 6.3 percent. A 3:1 cancer detection advantage of transrectal ultrasound over digital rectal examination was shown. Transrectal ultrasound and prostate-specific antigen each detected 92 percent of the proven cancers, and were complementary when either test was normal, together detecting 100 percent of the cancers. Thirty two percent (8/25) of all cancers were detected by digital examination, with digital exam having no predictive power after two study years. Prostate-specific antigen as an initial screening test for early prostate cancer may identify a suspicious group, whom may further be evaluated by transrectal ultrasound and digital exam. Results of this study lend credibility to the large scale randomized screening study proposed by the U.S. National Institutes of Health in which prostate-specific antigen and digital rectal examination are to be used as initial tests for prostate cancer detection.
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PMID:Transrectal ultrasound, digital rectal examination, and prostate-specific antigen: preliminary results of an early detection program for prostate cancer. 171 16

Markers of human prostatic cancer are important diagnostic aids in the management of this most common tumor among US men. A rapidly expanding body of basic and clinical knowledge about the properties and behavior of these unique organ-specific macromolecules bridges the gap between sophisticated immunochemistry and everyday practice. As a consequence, the patient benefits, because greater opportunities for early detection of prostatic cancer provide more freedom in selecting the most effective treatment modalities. Parallel improvement in quantitative assessment of an existing tumor mass allows earlier and more precise monitoring of the positive therapeutic responses and/or disease progression, as well as better overall prognosis. In addition, marker molecules can provide specific targets for antibody-directed therapeutic compounds active against prostatic cancer. This study focused on three such markers: prostatic acid phosphatase, prostate-specific antigen, and a new membrane-associated marker defined by a monoclonal antibody called 7E11-C5. A critical evaluation of clinical usefulness and prospects for future developments are presented.
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PMID:Lucy Wortham James Basic Research Award. Markers of prostatic carcinoma. 172 Sep 51

The effect of conjugation on the biodistribution of 111In-labelled antibodies was studied in nude mice carrying human prostatic cancer xenografts (PC-82). Two monoclonal antibodies and their fragments raised against human prostate-specific acid phosphatase (PAP) and prostate-specific antigen (PSA) were used. We used the cyclic anhydride of DTPA (CA-DTPA) as a chelating agent, or, alternatively, 1-(p-aminobenzyl)diethylenetriaminepentaacetic acid (NH2-Bz-DTPA) was attached as a linker to the carbohydrate components of the parent molecules. The conjugation method, the amount of circulating antigen and the size of the antibody component affected the blood clearance of the labelled derivatives. F(ab')2 fragments displayed a faster blood clearance than the corresponding derivatives of intact IgG1s. Aminobenzyl derivatives of anti-PAP-IgG1 showed a faster blood clearance than the corresponding CA-DTPA derivatives, but, in the case of derivatives of anti-PSA-IgG1, this was less clear, possibly due to the high PSA concentrations in the mouse sera. All the derivatives studied accumulated in the liver independently of the size of the antibody derivative, most probably due to the formation of antigen-antibody complexes. All CA-DTPA derivatives showed a higher kidney accumulation than the corresponding aminobenzyl derivatives. CA-DTPA-anti-PAP-F(ab')2 fragments showed a higher kidney uptake than the corresponding anti-PSA-F(ab')2 derivatives, since a large fraction of the latter are complexed with circulating antigen, thereby slowing down its reabsorption by the kidney. In addition, the lower kidney accumulation for anti-PSA-F(ab')2 fragments might be, at least partly, due to the electronegative charge of the molecule.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of conjugation on the biodistribution of 111In-labelled anti-PAP and anti-PSA monoclonal antibodies examined in nude mice with PC-82 human tumor xenografts. 172 16


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