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 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The proposal of an early diagnosis of prostate cancer through mass screening with digital rectal examination (DRE), transrectal ultrasound (TRUS) and serum tumor markers remains controversial: there is no high risk population. No study has proven that mass screening reduces the mortality from prostate cancer. However, when clinical and biological data give arguments for the presence of a cancer, every patient requires a prostate biopsy. We have studied the Positive Predictive Value (PPV) of each test in a selected population: 200 men over 50 years of age in which rectal examination or PSA assay was suspicious were investigated. Without any reference to the prostate volume, we considered that the PSA level was "suspicious" when it reached 3 times the upper reference value, or 12 ng/ml. DRE was suspicious in 73%, comprising 50% with prostate carcinoma. PSA assay was suspicious in 65%, comprising 61% with prostate carcinoma. 88% of cancers had a suspicious DRE or PSA assay. TRUS was suspicious in 89%, comprising 45% with prostate carcinoma. Ultrasound guided core biopsies were performed in each case, and allowed a positive diagnosis in 42% of cases, whereas bilateral fine-needle cyto-aspirates were positive in 87% of histologically proven carcinomas. Cytology alone was positive in 3 patients with negative biopsies. Both results show that the PPV of a suspicious DRE associated with an elevated PSA level is 84%. An increased PSA level is correlated with a cancer in 61%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Early diagnosis of prostatic cancer with digital rectal examination, PSA determination, and endorectal echography. Correlations with the morphologic diagnosis in 200 consecutive cases]. 128 56

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

The polyamines are normal cell constituents considered to have an important role in the regulation of proliferation and differentiation. DFMO is an irreversible, enzyme-activated, suicide inhibitor of ornithine decarboxylase (ODC), the enzyme responsible for the first and rate-limiting step in mammalian polyamine synthesis. Preliminary data show that DFMO inhibits tumor cell growth in vitro and in vivo, and that it demonstrates chemopreventive activity in a variety of animal tumors. The prostate contains some of the highest concentrations of polyamines and of polyamine-synthetic enzymes (including ODC) in the mammalian organism. ODC activity in the prostate was shown to be more susceptible to DFMO inhibition than in other organs. We have found the ODC activity of the Dunning R3327 rat prostatic carcinomas to be as sensitive to inhibition by DFMO as the normal rat prostate. Furthermore, DFMO was inhibitory to the growth of the tumor both in vitro and in vivo. Given the slow growth rate and long latency period of human prostate cancer and the preliminary DFMO data, we suggest that clinical trials to evaluate the chemopreventive potential of DFMO in prostatic carcinoma deserve serious consideration.
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PMID:Chemoprevention in prostate cancer: the role of difluoromethylornithine (DFMO). 128 67

All analyses of the efficacy of therapy for prostate cancer must control for the natural history of the disease. Over the past years, several long-term series involving several hundred patients have helped to describe the results of untreated disease. In general, most patients will not die of their disease, although approximately half of the patients will develop disease progression within 10 years. Predictors of progression include tumor stage, grade, and ploidy status.
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PMID:The natural history of adenocarcinoma of the prostate. 128 70

The nuclear DNA content of prostate cancer specimens, both needle biopsies and aspiration biopsy specimens as well as transurethral resection (TUR) chips and radical prostatectomy specimens, can now be reliably measured by standardized methods of flow and static image cytometry. For prostate carcinomas of every clinical stage (A1-D2), DNA diploid tumors have a better prognosis than tumors of a similar stage and grade which are non-diploid. Of particular importance to this symposium is the fact that DNA diploid stage D1 and D2 tumors treated early by androgen deprivation generally have a remarkably good prognosis. In contrast, those patients with DNA non-diploid tumors progress early despite androgen deprivation. Such a result suggests that DNA ploidy can be used to identify prostate cancers which are potentially sensitive to hormonal manipulation. Additional investigations from several groups indicate that early stage prostate malignant lesions, for example stages A1, A2, B1, and B2, are generally DNA diploid (about 75%). Swedish data suggest a steady progression of prostate cancer from early diploid to tetraploid, to non-tetraploid aneuploid, to multiple stemline aneuploid tumors with time and advancing stage. Taken together, these data suggest that the earliest detectable prostate carcinomas should be overwhelmingly DNA diploid. A large majority of these patients with early tumors should be candidates for "chemoprevention" by pharmacologic methods which reduce the effective androgen stimulation of prostate tumor cells.
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PMID:DNA ploidy: early malignant lesions. 128 72

The incidence of stage A (incidental) adenocarcinoma of the prostate in transurethral resection (TUR) specimens is approximately 16%. This paper discusses the criteria for differentiating stage A1 versus stage A2 tumor, based on tumor volume and grade. Both the short-term (4 year) and long-term (8-10 year) natural history of untreated stage A1 prostate cancer are examined. Options to follow patients expectantly are presented. These include digital rectal examination and transrectal ultrasound. Specific problems relating to analyzing transrectal ultrasounds in patients who have had a prior TUR are addressed. Also, the unique aspects of transrectal ultrasound for stage A1 disease as it relates to the location of the lesion are expanded upon. The third option in the management of stage A1 disease is to monitor serum prostate specific antigen (PSA) levels. Areas covered include the sensitivity and specificity of PSA in general, and, in specific, serum PSA levels following TUR for stage A1 disease as a predictor of residual tumor. New data on a small group of patients who underwent delayed radical prostatectomy following diagnosis of stage A1 disease, where PSA data was available, are presented. The rationale for following patients with stage A1 disease by monitoring their serum PSA levels is supported by data from a group of men with normally sized prostates, benign prostatic hyperplasia, or cancer where longitudinal serum PSA levels were available. Finally, the option of radical prostatectomy for stage A1 disease is put forth. Data include a study of a large group of radical prostatectomy specimens performed for stage A1 disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cancer detected incidental to simple prostatectomy (stage A1). 128 77

Human prostate carcinogenesis has been viewed as a multi-step process involving progression from low histologic grade, small, latent carcinoma to large, higher grade, metastasizing carcinoma. However, recent data suggest that a variety of pathogenetic pathways may exist. The precise etiology and pathogenesis of human prostate cancer remain largely undefined. It is difficult to investigate stages in the development of human prostate cancer, but some animal models provide opportunities in this regard. Short-term treatment of rats with chemical carcinogens produces a low incidence (5-15%) of prostate cancer, provided that prostatic cell proliferation is enhanced during carcinogen exposure. Chronic treatment with testosterone also produces a low prostate carcinoma incidence. A high carcinoma incidence can only be produced by chronic treatment with testosterone following administration of carcinogens such as N-methyl-N-nitrosourea (MNU) and 3,2'-dimethyl-4-aminobiphenyl (DMAB). Testosterone markedly enhances prostate carcinogenesis even at doses that do not measurably increase circulating testosterone. Thus, testosterone is a strong tumor promoter for the rat prostate. All such MNU- or DMAB-initiated and/or testosterone-promoted tumors are adenocarcinomas; most originate from the dorsolateral and anterior, but not ventral, prostate lobes. These tumors share a number of important characteristics with human prostate cancer. A high frequency (70%) of activation of the K-ras gene by a G35 to A mutation occurs in these carcinomas. Another high incidence prostate carcinogenesis model, representing a different pathogenetic pathway, involves chronic administration of estradiol-17 beta to rats in combination with low-dose testosterone. The resulting carcinomas are low-grade and originate exclusively from periurethral ducts of the dorsolateral and anterior prostate. While it is unknown whether testosterone is a tumor promoter in this system, preliminary studies indicate the formation of a DNA adduct in the target tissue, which suggests that estradiol-17 beta acts as a tumor initiating agent in this system. The high incidence models mentioned earlier are adequate for the study of chemoprevention of prostatic carcinogenesis. Analysis of shifts in the relative incidence of metastasizing carcinoma, grossly apparent but not-metastasizing carcinoma, microscopic-size carcinoma, and carcinoma in situ or atypical hyperplasia may allow study of the modifying effects of potential chemopreventive agents on tumor progression in these animal models of prostatic carcinogenesis.
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PMID:Animal models for the study of prostate carcinogenesis. 128 79

A human prostate cancer model was established by inoculating a prostate specific antigen (PSA)-producing LNCaP cell line with either prostate or bone fibroblasts. Alternatively, this human prostate cancer model can also be established by inoculating LNCaP cells with growth factor(s) (GFs) and extracellular matrix (ECM) immobilized on Gelfoam. The resulting LNCaP tumors were used to evaluate PSA production and excretion in athymic hosts. This model was also employed to examine the biochemical nature of mesenchymal cell-derived growth-promoting protein(s) and to assess the efficacy of potential chemotherapeutic agents. Because of the propensity of human prostate cancer to metastasize to the bone, this study defined a 1.0 M NaCl-eluted fraction, MS1, from the conditioned medium of a bone stromal cell line (MS) by heparin-affinity column chromatography. The growth-promoting activity was assayed both in vivo (e.g., tumor formation) and in vitro (e.g., soft agar colony formation). We found that the growth-promoting activity was trypsin- and heat-sensitive, and partially degraded by acid and dithiothreitol. Immunochemical studies indicated that the polyclonal antibody raised against MS1 blocked the growth-promoting effect elicited by the bone-conditioned media. This growth-promoting factor was found to be immunochemically dissimilar to KGF, HGF, and bFGF. However, addition of bFGF, HGF and NGF, but not aFGF, TGF beta, IGF1, IGF2, PDGF, EGF, TGF alpha and KGF, stimulated anchorage-independent growth of prostate cells, a condition closely parallel to tumor formation in vivo. We found that the MS1 fraction also contained fibronectin and tenascin but not laminin or collagen IV.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Human prostate cancer model: roles of growth factors and extracellular matrices. 128 80

Prostate cancer is a disease mostly effecting aged men. The incidence rate of this disease is much lower in China than in Europe and America. However, certain data have been accumulated indicating an increasing tendency in this country in recent years. The present report also supports this view and suggest the importance of strengthening of epidemiological research in this area in future. The problem how to treat patients with advanced prostate cancer is of essential importance since most cases are diagnosed in III or IV stage of the disease. In the present study, 10 out of 26 suspected cases (38.5%) was diagnosed by needle aspiration biopsy, being 90.9% of 11 cases confirmed histopathologically. The elevation of tumor maker acid phosphatase activity was positive in 8 out of 17 cases (47.1%). In this group, 11/17 (64.7%) received bilateral orchidectomy plus estrogenic hormones. The effective rate was 81.9% (9/11). Relapse occurred in 4 out of the 9 cases (44.4%), probably due to estrogenic hormone-dependence.
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PMID:[Advanced prostate cancer--an analysis of 17 cases]. 129


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