Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 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.
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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

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)
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PMID:Digital rectal examination, imaging, and systematic-sextant biopsy in identifying operable lymph node-negative prostatic carcinoma. 128 72

Prostate cancer is a significant health problem for blacks. The incidence and mortality rates are higher in blacks than in whites; blacks often present with a higher stage. Prostate-specific antigen (PSA) is a very useful serum marker in prostate cancer. We analyzed data from a cohort of 161 patients to determine whether there were any racial differences in PSA levels prior to treatment in local-regional prostate cancer. The immunoradiometric method was used to determine the PSA values. The mean PSA levels were significantly higher in blacks than in whites (P = 0.022), and the difference remained significant in multivariate analysis after adjusting for stage and grade (P = 0.020). However, when analyzed further, the difference was statistically significant in one hospital (P = 0.001) and not in another (P = 0.493). Thus, our results are not unequivocal, but our data do suggest that racial differences in PSA levels not accounted for by tumor stage or grade may exist. Assuming that the data truly reflect a racial difference, the cause(s) of this difference remains to be determined. It may exist because, within each clinical stage, blacks are presenting with a higher tumor cell burden, or it may be indicative of more aggressive biological behavior. The possibility that racial differences are due to socioeconomic factors was considered by estimating median income level from zip code of residence; although a correlation between socioeconomic status and PSA level was found, racial differences remained borderline significant (P = 0.055) after adjusting for income level (in addition to stage and grade).
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PMID:Racial differences in prostate-specific antigen levels in patients with local-regional prostate cancer. 128 91

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)
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PMID:Neoadjuvant hormonal manipulation: a strategy for chemoprevention trials. 128 66

Cystosarcoma phyllodes of the prostate is a rare neoplasm, occurring in adult men. It closely resembles the not uncommon tumor of the female breast and usually behaves in a similar manner. This case of benign cystosarcoma phyllodes of the prostate occurred in a 53-year-old man who presented with increasing abdominal girth and underwent exploratory laparotomy and removal of the 11.2-kg tumor. It was remarkable for its very large size and the presence of foci of well-differentiated adenocarcinoma, prostatic acinar type. The glandular epithelium of both the phyllodes tumor and the carcinoma were immunoreactive for cytokeratin, epithelial membrane antigen, prostate-specific antigen, and prostate-specific acid phosphatase. The presence of typical prostatic type adenocarcinoma and this immunoreactivity pattern strongly supports a prostatic origin for this rare neoplasm.
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PMID:Giant cystosarcoma phyllodes of the prostate associated with adenocarcinoma. 131 Feb 47

An evaluation of the effects of blood transfusion on recurrence and survival after radical surgery for prostate cancer was performed. Between 1982 and 1986, 315 consecutive patients underwent radical retropubic prostatectomy by a single surgeon; of 309 patients for whom transfusion data were available, 94 received homologous blood (Group I) and 215 received autologous blood or no blood (Group II). At the time of surgery, there were no differences between Group I and Group II with respect to age, preoperative cancer stage, preoperative histologic grade (Gleason grade), prostatic acid phosphatase score, and preoperative potency. At discharge, the groups were similar in the status of neurovascular bundles, capsular involvement, seminal vesicle involvement, lymph node involvement, postoperative Gleason grade, and postoperative potency. No adjuvant hormone therapy or radiation therapy was administered until tumor recurrence. The patients were followed annually by physical examinations and measurements of prostate-specific antigen. Cancer recurrence was detected in 23 (24.5%) Group I patients and 49 (22.7%) Group II patients. These proportions were not significantly different in univariate or multivariate analysis, and the time to recurrence curves overlapped. It is concluded that homologous blood transfusions are not associated with more rapid tumor recurrence or death after radical surgery for prostate cancer than is seen with autologous transfusions. These results differ from previous reports, which suggested that transfusions may cause recurrence of cancer in patients with colorectal or prostate cancer because of the immunosuppressive effects of blood transfusions.
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PMID:Prostate cancer recurrence in radical surgery patients receiving autologous or homologous blood. 137 May 92

Prostate-specific antigen (PSA) is the most sensitive marker available for monitoring the progression of prostate cancer and response to therapy. In a previous study, we demonstrated tissue-specific expression of PSA glycoprotein and mRNA and its regulation through the androgen receptor. In this study, we examine the effects of protein kinase A (PKA) and protein kinase C (PKC) on the androgen regulation of PSA in a human adenocarcinoma cell line, LNCaP. Northern blot analysis demonstrated that forskolin, an activator of PKA, had no effect on the androgen regulation of PSA. However, the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA), a direct activator of PKC, showed a time- and dose-dependent repression of the androgen regulation of PSA glycoprotein and mRNA. The biologically inactive phorbol ester, 4 alpha-phorbol-12,13-didecanoate, had no effect. Staurosporine, a PKC inhibitor, blocked the TPA-mediated repression of the androgenic stimulation of PSA glycoprotein. In addition, the calcium ionophore, A23187, was able to simulate the actions of TPA, presumably through activation of PKC via calcium mobilization. In summary, the androgenic regulation of PSA protein and mRNA is repressed by tumor-promoting phorbol esters through the PKC pathway. This indicates that the effects of TPA may be secondary to repressed gene transcription or altered mRNA stability. In addition, this study emphasizes that the androgenic regulation of PSA is complex and may involve other extracellular transduction signals.
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PMID:Tumor-promoting phorbol ester down-regulates the androgen induction of prostate-specific antigen in a human prostatic adenocarcinoma cell line. 137 17

The ability of prostate-specific antigen (PSA) to predict tumor volume and stage in patients with prostate cancer would be improved if factors regulating its production and clearance were better defined. A thorough understanding of the pharmacokinetics (regulation of production, metabolism, and excretion) of PSA has been precluded, however, by the absence of an in vivo animal model. The purposes of this study are to develop a murine model for evaluating PSA pharmacokinetics in vivo and to assess factors that influence PSA production in vitro. The human prostate cancer cell line, LNCaP, was chosen because it is androgen sensitive and PSA positive. Although LNCaP cells are usually nontumorigenic when inoculated s.c. in athymic mice, coinoculation of 1 x 10(6) LNCaP cells with 1 x 10(6) human bone fibroblasts reliably produces PSA-secreting carcinomas. This LNCaP model provides accurate correlation between tumor volume and serum PSA levels (r = 0.94) and demonstrates that tumor volume and androgens are codeterminants of circulating PSA levels. Following castration, serum PSA levels decrease rapidly up to 8-fold and increase up to 20-fold following androgen supplementation, without detectable castration-induced tumor cell death or concomitant changes in tumor volume. Serum PSA levels increase 0.24 ng/ml/mm3 of tumor, which is approximately 5-fold less than that estimated for humans. Most likely this reduced PSA index (PSA:tumor volume ratio) results from a 7-fold faster clearance of PSA in athymic mice than in humans; other than this shorter half-life, PSA elimination in the murine model appears similar to that in humans, with both following first-order kinetics characteristic of a two-compartment model. Interestingly, following prolonged growth (greater than 21 days) in castrate hosts, LNCaP tumors are capable of adapting to an androgen-deprived environment whereby LNCaP tumors regain the ability to secrete PSA in amounts similar to the precastrate state. In LNCaP cells, androgens increase PSA mRNA levels 4-fold in vivo and in vitro. PSA mRNA expression is also altered by various growth factors. Changes in PSA production induced by androgens and growth factors do not always parallel changes in LNCaP cell growth rate induced by these factors, suggesting that PSA production occurs independently of cell growth rate and may be influenced by various interrelated factors, including hormonal and stromal milieu. Observations from this murine model suggest that androgens and tumor volume are independent determinants of serum PSA levels and imply that decreases in circulating PSA following antiandrogen therapy may not always reflect a corresponding reduction in tumor volume.
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PMID:Serum prostate specific antigen levels in mice bearing human prostate LNCaP tumors are determined by tumor volume and endocrine and growth factors. 137 18

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

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


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