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

Serum values of prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) were determined in 180 patients prior to pelvic lymphadenectomy and radical prostatectomy and in 40 patients prior to pelvic lymphadenectomy alone. In all tumor stages, PSA was superior to PAP in detecting cancer of the prostate. By PSA determination using a cutoff level of 4 ng/ml (Tandem assay), 28.8% of the patients with prostate cancer, stage pT2pN0M0, and 17.8% of the cases with a stage pT3pN0M0 tumor could not be detected. All these tumors had been noticed, however, by digital rectal examination. This indicates that PSA determination cannot replace digital rectal examination as a screening method for prostate cancer. In this study, it was possible neither by PSA nor by PAP to define a practicable cutoff level for patients with and without lymph node metastases. A clear differentiation between the stages pT2pN0M0 and pT3pN0M0 was not possible by either PSA or PAP alone.
 ...
PMID:Prostate-specific antigen and prostatic acid phosphatase in the detection of early prostate cancer and in the prediction of regional lymph node metastases. 128 Nov 2

Transrectal ultrasound (TRUS) has shown some promise in the staging of prostate cancer, while prostate-specific antigen (PSA) alone is insufficient. By combining prospective TRUS evaluation with retrospective PSA analysis, we demonstrated an increased accuracy of this combined staging method over TRUS alone. In 48 men undergoing radical prostatectomy, TRUS was performed and PSA measured pre-operatively. On the basis of TRUS, tumours were classified as contained or uncontained. An "expected" PSA value was then calculated for each patient as follows: K x volume of hypoechoic area +0.07 x prostate volume where K = 2.1 if the combined Gleason score of the initial biopsy was > or = 7, or 4.2 if the score was < or = 6. If a patient's pre-operative PSA value was less than or equal to the expected PSA, his tumour was judged to be contained. Staging by both TRUS and PSA was combined, so that if the tumour was judged uncontained by either parameter, the combined prediction was uncontained. Results of the combined staging were: sensitivity 84%, specificity 82%, positive predictive value 94%, negative predictive value 60%, accuracy 83%. This PSA formula, which takes into account the size and grade of the lesion rather than an arbitrary cut-off value, enhances the local staging of prostate cancer by TRUS.
 ...
PMID:Staging of prostate cancer. Accuracy of transrectal ultrasound enhanced by prostate-specific antigen. 128 24

The early detection and staging of prostatic carcinoma are challenging the diagnostic acumen of urologists. Mass screening programmes of asymptomatic men are not justified, as only a small number of cases are diagnosed when the tumour is confined to the prostatic capsule. Diagnostic work-ups of symptomatic men yield a similarly low rate of detection. The most extensively used diagnostic methods include digital rectal examination (DRE), transrectal ultrasound (TRUS) and prostate-specific antigen (PSA) assay. Although DRE is an inexpensive technique that improves early detection, its sensitivity and specificity are low. The specificity and sensitivity of TRUS are higher, but false-positive and false-negative rates are significant. In a study of 566 patients, the rates were 86% and 84%, respectively. A determination of PSA may be informative in the early stages of prostatic cancer, but confirmation of the results by other methods is necessary. Thus, there is no safe method to achieve early diagnosis and precise staging of prostatic carcinoma. Only clinical trials comparing all the different methods will help to establish the definitive role of each one.
 ...
PMID:Diagnostic challenges of prostatic carcinoma. 128 31

Serum prostate-specific antigen (PSA) levels in patients with prostate cancer and benign prostate hypertrophy (BPH) were investigated with a newly developed enzyme immunoassay (MARKIT-M PA, Dainippon Pharmaceutical Co. Ltd., Osaka, Japan). Sensitivity of the assay system is 0.5 ng/ml and the detection range is 0.5-100 ng/ml. There was a high linear correlation (r = 0.987) between the assay and MARKIT-F PA, and values obtained with the assay were almost equal to those yielded by MARKIT-F PA assay. Using the BPH group as a negative control, the upper cut-off value in BPH patients was determined to be 3.6 ng/ml. Of the 48 patients with untreated prostate cancer, 77% was detectable by means of MARKIT-M PA assay. Using the BPH group as a negative control, specificity and efficiency were 93% and 86%, respectively. In another group of 27 BPH patients whose blood samples were taken immediately after digital prostatic examination, PSA was elevated in 15%. During follow-up of prostate cancer patients, PSA was elevated in 82% at the time of clinically detectable progression. In 15 patients whose disease was clinically well controlled, all levels of PSA were observed to be negative. These findings suggests that detection of serum PSA with this assay is of great use both in the diagnosis and monitoring of prostate cancer patients.
 ...
PMID:[Value of prostate-specific antigen measurements with newly developed enzyme immunoassay (MARKIT-M PA)]. 128 72

The value of digital rectal examination, computerized tomography, magnetic resonance imaging, prostate-specific antigen, transrectal ultrasonography, and systematic-sextant biopsy in the identification of lymph node-positive patients before radical prostatectomy was analyzed in 103 men who had pelvic lymph node dissection, CT had a sensitivity of only 7% and a specificity of 96% in detecting lymph nodes, whereas magnetic resonance imaging had a sensitivity of 50% and a specificity of 100%. To evaluate the use of tumor volume in predicting lymph node metastasis, we counted the number of positive core biopsies and compared the results with the incidence of positive lymph nodes. If fewer than 5 positive core biopsies were considered negative for predicting lymph node metastasis, the sensitivity would be 67% (12 of 18), and the specificity 94% (50 of 53). To investigate tumor volume more precisely, we measured the extent of tumor volume in every biopsy as a percentage of the total biopsy core and added the percentage for the 6 biopsies. The lowest score was 10% (10% prostatic cancer in 1 of 6 cores), the highest score 580% (4 cores with 100% each and 2 with 90% each). The score was analyzed for sensitivity and specificity in predicting lymph node metastasis. If a score of 280% was used as a cutoff point, the sensitivity was 71% (10 of 14) and the specificity 91% (52 of 57). When we include the grading system by multiplying the percentage of tumor volume with tumor grade, the difference between the lymph node-positive state and lymph node-negative state becomes even more readily apparent.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Digital rectal examination, imaging, and systematic-sextant biopsy in identifying operable lymph node-negative prostatic carcinoma. 128 72

The purpose of this study was to develop a reliable screening test for prostate cancer. Monoclonal antibodies specific to the prostate-specific antigen (PSA) were generated with an improved hybridoma technique. The hybrid cells were initially cultured in a semisolid medium containing methylcellulose and later transferred to a liquid medium for further subculture. Thirty-six out of a total 1,250 recovered colonies were shown to exhibit a high affinity to PSA by radioimmunobinding assay. Eight hybrid cell lines which secreted either IgG1 or IgG2a antibodies of a high affinity and specificity were established for evaluation. The association constants between PSA and these monoclonal antibodies were shown to range from 1 x 10(9) to 5 x 10(9) M-1. From the results of a matrix cross-matching procedure, pairs of monoclonal antibodies were identified and the corresponding epitopes assigned, and most of them could also be paired with rabbit anti-PSA in a typical sandwich enzyme immunoassay. The designated EIA procedure was performed over 90 minutes at room temperature in a two-stage incubation protocol with a sensitivity of 0.4 ng/mL. The EIA kit was shown to have little cross-reactivity with thyroid stimulating hormone, alpha-fetoprotein, carcinoembryonic antigen and prostate acid phosphatase. Preliminary evaluations with clinically defined patients' sera revealed that proper selections of antibody pairs in sandwich immunoassays are crucial to the adequate performance of the EIA kits.
 ...
PMID:Enzyme immunoassay for prostate-specific antigen and its diagnostic application in prostate cancer. 128 38

Prostate-specific antigen is a kallikrein-like serine protease that is produced exclusively by the epithelial cells of all types of prostatic tissue, benign and malignant. Physiologically, it is present in the seminal fluid at high concentration and functions to cleave the high molecular weight protein responsible for the seminal coagulum into smaller polypeptides. This action results in liquefaction of the coagulum. Prostate-specific antigen is also present in the serum and can be measured reliably by several different assays. Although the protein is prostate-specific, it is not prostate-cancer-specific. As a result, benign conditions such as benign prostatic hyperplasia, prostatitis and infarction, as well as prostatic intraepithelial neoplasia, can be associated with elevated serum levels of prostate-specific antigen. Approximately 25% of men with benign prostatic hyperplasia have an elevated serum value of prostate-specific antigen, whereas 35% to 40% of patients with organ-confined prostate cancer have a level within the reference range. Prostate-specific antigen can identify some cancers not detectable by digital rectal examination; alternatively, this examination can identify cancers not detectable from the serum prostate-specific antigen concentration. Thus, the most complete evaluation of the prostate gland is achieved when both the prostate-specific antigen value and the digital rectal examination are used. The density and the rate of change of serum prostate-specific antigen are new concepts to improve the ability of prostate-specific antigen to detect early prostate cancer. Preliminary results are encouraging, but additional studies are required to determine the true usefulness of these new variables. Thus, in 1992, determination of the prostate-specific antigen value is a valuable new tool for the practicing physician and will be instrumental in our campaign to diagnose clinically significant prostate cancer at an early, curable stage.
 ...
PMID:Prostate-specific antigen and diagnosing early malignancies of the prostate. 128 95

Prostate-specific antigen levels are increased in men with prostatic disease, including prostate cancer, and have been used clinically to monitor the response of prostate cancer to therapy. More recently, prostate-specific antigen levels, usually in combination with digital rectal examination or transrectal prostatic ultrasonography, have been suggested to be useful for the detection of prostate cancer. To evaluate the association between a single serum prostate-specific antigen level and the subsequent development of prostate cancer, we measured serum levels in 35 men who donated blood to a community-based serum bank in 1974 and who subsequently developed prostate cancer and in 35 matched controls from the same group of volunteers. Levels of prostate-specific antigen were significantly higher in men who went on to develop prostate cancer, up to 6 years prior to the time of diagnosis in the cases. The level of prostate-specific antigen decreased with increasing time to diagnosis. The mean level for prostate cancer cases diagnosed within the first 3 years of follow-up was 16.2 micrograms/liter compared to 2.4 micrograms/liter for controls (P = 0.002). The mean level for cancer cases diagnosed in years 4 through 6 following blood sampling was 9.6 micrograms/liter compared to 1.3 micrograms/liter for controls (P = 0.0002). The sensitivity and specificity of a prostate-specific antigen level > or = 4 micrograms/liter up to 3 years prior to the time of clinical diagnosis were both 75% and up to 6 years were 67% and 85%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Prostate-specific antigen levels and subsequent prostate cancer: potential for screening. 1882 Feb 78

Androgen ablation using hormonal manipulation is used extensively in metastatic prostate cancer; however, its use in localized disease combined with surgical extirpation of the gland has not been thoroughly and systematically investigated. The rationale for neoadjuvant therapy stems from the demonstrated effectiveness of androgen ablative therapy in metastatic disease and the high rate of "positive" surgical margins, especially in patients with Stage B2 disease. In addition, the essentially anecdotal clinical report of Scott and Boyd [1], using endocrine therapy plus radical prostatectomy in patients with Stage C disease, gives 15 year survival results comparable to those obtained by Jewett [2] in Stage 1 patients treated by radical prostatectomy. Finally, experimental observations in the androgen-sensitive mammary tumor (Shionogi) lend support to the concept of neoadjuvant hormonal manipulation. A pilot study of neoadjuvant endocrine therapy in 55 patients treated at Memorial Sloan-Kettering Cancer Center with 3 months of diethylstilbestrol (DES) (3 mg/day) prior to radical prostatectomy indicates marked reductions in prostate-specific antigen (PSA), although persistent evidence of adverse local tumor features was common. Some patients, however, exhibited evidence of significant downstaging. Whether or not any alteration in disease progression will accrue from demonstrated local downstaging is, of course, uncertain. However, clinical and laboratory effects of such treatment may provide a means for correlation with subsequent tumor behavior, and may prove useful in treatment decisions. Additionally, a decrease in the number of foci of grade 3 prostatic intraepithelial neoplasia (PIN-3) was noted in a small number of patients.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Neoadjuvant hormonal manipulation: a strategy for chemoprevention trials. 128 66

Both amplification and overexpression of c-erb B-2/neu have been associated with the progression and possible prognosis of a number of human cancers. In this study, we demonstrated that c-erb B-2/neu may also play an important role in human prostate cancer. Our conclusion is based on the following observations: (1) A monoclonal antibody raised against a peptide sequence from the C-terminal domain of the human c-erb B-2/neu gene product reacted positively with 68.7% (11 of 16) of the human prostatic cancer tissue extracts analyzed by western blot procedure. These results were supported by the immunohistochemical staining of the prostatic cancer specimens; 80% (12 of 15) showed positive staining, primarily around the plasma membranes of the prostatic cancer cells. c-erb B-2/neu oncoprotein was not detectable in normal prostate tissues (five examined by immunohistochemical staining and three by western blotting) or in human benign prostatic hyperplasia (two examined by immunohistochemical staining and six by western blotting) and was expressed less abundantly with lower intensity in "normal" human prostate tissues adjacent to cancerous prostate tissue (5 of 12 examined by immunohistochemical staining). We observed no evidence of c-erb B-2/neu gene amplification in 10 fresh human prostatic cancer specimens examined by Southern blotting and in the cultured human prostatic cancer cell lines PC-3, DU-145, and LNCaP. (2) The c-erb B-2/neu protein was detected in both androgen-receptor-positive (LNCaP) and -negative (PC-3 and DU-145) human prostate cancer cell lines. Positive immunostaining of c-erb B-2/neu protein was found to be associated predominantly with the plasma membranes of PC-3 cells, but was also found to be widespread in the cytoplasmic region of the LNCaP cells and in the perinuclear region of the DU-145 cells. (3) Like prostate-specific antigen (PSA) expression, c-erb B-2/neu mRNA expression was also positively regulated by androgen in androgen-receptor-positive LNCaP cells in vitro and LNCaP tumors in vivo. When LNCaP tumors were grown in castrated male hosts, levels of c-erb B-2/neu and PSA mRNA expression decreased initially, but rebounded at 3 wk to levels comparable to those expressed by tumors maintained in intact adult male hosts.
 ...
PMID:Expression of c-erb B-2/neu proto-oncogene in human prostatic cancer tissues and cell lines. 135 65


1 2 3 4 5 6 7 8 9 10 Next >>