Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostate specific antigen is an abundant prostate-derived serine protease in the seminal fluid. Low concentrations of the protein are normally released into blood, but above normal concentrations are frequently detected in prostate disease. The PSA-ACT complex is the predominant molecular form of serum PSA (up to approximately 95%) although complex formation is slow between the purified proteins in vitro. A free, noncomplexed form of PSA constitutes a minor fraction of the serum PSA, although serum ACT occurs in large molar excess. The free, noncomplexed form of serum PSA is reported to constitute a significantly smaller proportion of the PSA in untreated prostate cancer than in BPH. The molecular basis for this finding is unclear, but measurements of the proportion of the free form of serum PSA or the proportion of serum PSA-ACT may facilitate discrimination between prostate cancer and BPH.
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PMID:Significance of different molecular forms of serum PSA. The free, noncomplexed form of PSA versus that complexed to alpha 1-antichymotrypsin. 750 76

The association of estrogens with benign prostatic hyperplasia and prostatic cancer has been widely studied, but no conclusive evidence exists for a role of estrogens in prostatic disease. This paper reviews the literature and describes studies which have sought to show a correlation of estrogens and alterations in the prostates of humans and experimental animal models. Using the developmentally estrogenized mouse model, we propose an alternative role for estrogens as a predisposing factor for prostatic diseases: estrogen exposure during development may initiate cellular changes in the prostate which would require estrogens and/or androgens later in life for promotion to hyperplasia or neoplasia. Thus, the critical time for estrogen action would be during the development of the prostatic tissue. We further suggest that estrogen-sensitive cells may remain in the prostate and be more responsive to estrogens later in life or less responsive to the normal controlling mechanisms of prostatic growth.
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PMID:Developmental estrogenization and prostatic neoplasia. 750 22

The results of a mass screening examination for prostate cancer conducted from 1989 to 1993 at a local town, Kawagoe-cho, in Mie Prefecture were evaluated. Among the 216 examinees, 4 were found to have prostate cancer. The most accurate examination was the prostate specific antigen (PSA), which was followed by digital examination and transrectal ultrasound. The applicants for the prostate cancer screening accounted for only 8% of the Kawagoe-cho male residents over 40 years old. An educational campaign of prostate disease in the area must be started to increase the number of applicants. We concluded that the most effective modality for the screening program was a combination of PSA and digital examination in the field study, and transrectal ultrasound accompanied by systemic biopsy results in the second tool for screening.
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PMID:[Mass screening for prostate cancer at a local town--five-year results and screening system]. 751 44

Prostate Cancer Awareness Week was begun in 1989 to investigate whether men could be recruited to participate in free prostate cancer screening. Initially designed to raise public awareness of "the ignored male disease", it has become the largest single cancer screening program in the United States. In 1992, more than 500,000 men were examined by digital rectal examination (DRE) and more than half of these also by measuring prostate-specific antigen (PSA). Although the populations examined have been generally better educated than the national average, predominantly white, and typically (> 40%) experiencing some symptom of prostate disease, adherence to annual prostate examinations remains low among successive cohorts of participants. Prostate cancers detected through this program exhibit a more favorable stage distribution than the national average. From 1989 through 1992, many cancers were detected by using the effective combination of DRE and PSA testing, which resulted in more stage A disease being diagnosed and fewer stage B, C, and D tumors. Data from 1992 suggest that increasing sophistication is possible with PSA test results, and age-specific PSA reference ranges have been developed.
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PMID:Prostate Cancer Awareness Week, 1992: a summary of key findings. 751 33

Although prostate cancer and benign prostatic hyperplasia are major health problems in U.S. men, little is known about the early stages of the natural history of prostate disease. A molecular biomarker called prostate specific antigen (PSA), together with a unique longitudinal bank of frozen serum, now allows a historic prospective study of changes in PSA levels for decades prior to the diagnosis of prostate disease. Linear mixed-effects regression models were used to test whether rates of change in PSA were different in men with and without prostate disease. In addition, since the prostate cancer cases developed their tumours at different (and unknown) times during their periods of follow-up, a piece-wise non-linear mixed-effects regression model was used to estimate the time when rapid increases in PSA were first observable beyond the background level of PSA change. These methods have a wide range of applications in biomedical research utilizing repeated measures data such as pharmacokinetic studies, crossover trials, growth and development studies, aging studies, and disease detection.
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PMID:Mixed-effects regression models for studying the natural history of prostate disease. 751 70

Correct forecasting of prostatic carcinoma by means of serum PSA is limited. Prostatic carcinoma is said to increase PSA 10 times as much as prostatic adenoma. Therefore we evaluated whether PSA in the prostatic fluid is more specific for prostatic carcinoma than the level in the serum. In 31 consecutive patients with prostatic disease blood was taken for serum PSA first and then prostatic fluid (10 microliters) was expressed. The PSA was determined by the Pros-Check test in both the serum and in the prostatic fluid. The collection of the prostatic fluid failed in 7 (22.6%) patients. Of the remaining 24 patients, 5 had documented bacterial prostatitis, 4 had prostatic carcinoma and 15 had benign prostatic hyperplasia (BPH). The serum PSA was 5.6 +/- 5.0 micrograms/l in prostatitis, 148 +/- 208 micrograms/l in prostatic carcinoma and 6.9 +/- 6.8 micrograms/l in BPH. The serum PSA was significantly higher in prostatic cancer (P < or = 0.01) than in prostatitis and BPH. The PSA levels in the prostatic fluid were 14.0 +/- 25.7 x 10(6) micrograms/l in prostatitis, 7.6 +/- 9.7 x 10(6) micrograms/l in carcinoma and 14.0 +/- 14.6 x 10(6) micrograms/l in BPH. There were no statistically significant differences. In the expressed prostatic fluid no significantly different PSA was found in carcinoma, bacterial prostatitis or BPH. In contrast to this, the serum PSA was significantly higher in cancer patients than in prostatitis or BPH. Therefore PSA in the expressed prostatic fluid is no more specific than that in the serum.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[PSA in prostatic fluid]. 751 4

Until recently, the only information on the growth rate of prostate tumors has been derived from cross-sectional histological labeling studies, autopsy data and clinical studies of patients managed expectantly. However, serial measurements of prostate specific antigen (PSA) may now allow studies of the natural history of the earliest stages of prostate cancer. Frozen sera samples from the Baltimore Longitudinal Study of Aging have been used to compare the patterns of change in PSA levels in men with and without prostate cancer up to 25 years before the diagnosis of cancer. Men with no prostatic disease exhibited a slow linear increase in PSA levels, whereas benign prostatic hyperplasia cases showed a gradual acceleration in the rate of change in PSA. In contrast, cancer cases exhibited an early linear phase followed by an exponential phase of increase in PSA levels before diagnosis. On average, the exponential phase of PSA increases began 7 to 9 years before the tumors were detected clinically. Thus, there is a significant window of opportunity for early detection of prostate cancer. The changes in PSA observed in men with and without prostate cancer are consistent with available information on prostatic growth and the long natural history of prostate cancer. A better understanding of the various factors that affect serum PSA levels may allow more effective use of PSA measurements to detect early stage tumors and predict the biological potential of a tumor.
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PMID:Natural history of changes in prostate specific antigen in early stage prostate cancer. 752 17

Our knowledge of prostate cancer is less well-defined than our knowledge of cancers of other organs. In the colon, for example, morphological criteria to identify carcinomas in situ and some putative preneoplastic lesions are clear; phenotypic differences in the expression of enzymes and antigens are documented in experimental models and are starting to be defined in humans. Experimental models of cancer of the liver and colon show evidence that "enzyme-altered foci" are preneoplastic. In these organs, the "normal" context is much clearer than in the prostate. In contrast, in the prostates of men in the same age range as those who develop prostate cancer, morphological aberrations are almost always present, diverse, and poorly understood. Murphy and Gaeta said that, "in the study of prostatic disease..., almost every aspect remains controversial...[and].... many of the 'known facts' concerning prostatic disease are poorly documented..." While being aware that the definitions of all benign and malignant lesions of the prostate are based on complex morphological criteria which must form the contemporary context for comparisons, our laboratory is searching for markers that will permit the identification of putative preneoplastic lesions in the prostate. In our opinion, these changes will not be found most efficiently, if they are present at all, in long established cell lines, advanced carcinomas, or serially transplantable xenografts of primary prostatic carcinomas. Our preliminary data suggest that several enzyme histochemical and immunohistochemical approaches are worthy of study. Markers that show promise include acid phosphatase, 5'-nucleotidase, leucine aminopeptidase, and CD44.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Putative preneoplastic foci in the human prostate. 752 54

In an endeavor to identify marker(s) for prostatic cancer, proteins in prostatic fluids were analyzed by two-dimensional (2-D) gel electrophoresis. The fluids were obtained from five males who had no prostate lesions and five patients each with benign prostatic hyperplasia (BPH) and prostatic carcinoma (PCA). The specimens were collected directly over a mixture of protease inhibitors and centrifuged, and the supernatants were lyophilized and solubilized in sodium dodecyl sulfate mix. Identical amounts of proteins were pooled according to donors' prostate disease and the resulting samples were subjected to 2-D gel analysis employing the ISO-DALT system. The electrophoretograms were developed by silver or double stain. The samples of each group exhibited distinctive profiles with the exception of similar relative positions of major protein spots. A predominant protein occurring as several charge variants was consistently present in prostatic fluids of patients with PCA. This protein appeared to be a previously unknown constituent that we have called protein D (molecular weight approximately 22 kDa and isoelectric point approximately 4), and was undetectable in the fluids of "normal" men and patients with BPH. An analysis of pooled, unprocessed urine from PCA patients revealed that perhaps this protein is excreted in urine in very low quantities. These results strongly suggest that the potential of this protein as a marker for prostatic cancer should be further explored.
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PMID:Analysis of prostatic fluid: evidence for the presence of a prospective marker for prostatic cancer. 753 24

Great interest has been generated recently in preoperative androgen deprivation for clinical stage B ou C (T2 ou T3) prostate cancer. The influence of neoadjuvant hormonal therapy on down-staging and down-grading is still controversial. To assess the influence of preoperative androgen deprivation on serum PSA levels, we compared pre- and post-treatment serum PSA levels in 54 patients who received complete pre-operative androgen blockade (LHRH agonist + flutamide) 3 months prior to surgery. All patients with a pretreatment PSA > 20 ng/ml had extra-prostatic disease excepted two patients who presented lesions of acute prostatitis with adenocarcinoma. After hormonal deprivation, 51/54 patients experienced a return of PSA to normal values (< 4 ng/ml). Among this patient, 33 had undetectable PSA levels (< 0.25 ng/ml). 90% of the patients with undetectable had tumor confined to the gland (pT2/B). On the other hand, patients who still have PSA > 4 ng/ml after hormonal deprivation, had extra-prostatic cancer (pT3-pT4). Thus, PSA levels after 3 months neo-adjuvant hormonal treatment might have a useful predictive value in patients selection for radical surgery.
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PMID:[Predictive value of the serum PSA level in patients having undergone neo-adjuvant hormone treatment before radical prostatectomy]. 753 12


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