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Query: UMLS:C0600139 (Prostate Cancer)
 4,540 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In recent years the introduction of serum prostate-specific antigen (PSA) determination as a screening tool for early detection of prostate cancer in asymptomatic men has led to a markedly increased detection of prostate cancers that are neither palpable nor visible with transrectal ultrasonography (stage T1c). In this preliminary study we assessed pathologic features and aspects that are indicative of clinical significance in T1c tumors and tumors with palpable or visible lesions (non-T1c tumors). Between June 1994 and December 1995, 51 consecutive radical prostatectomies were performed on screened participants in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC). After determination of pathologic stage and Gleason score, morphometric analysis was performed to determine tumor volume. Radical prostatectomy specimens were divided into three mutually exclusive subsets: T1c tumors, non-T1c tumors with preoperative PSA levels below 4 ng/ml, and non-T1c tumors with PSA levels equal to or greater than 4 ng/ml. These subsets were compared for differences in the distribution of tumor volume, pathologic stage, and Gleason score. An arbitrarily constructed categorization model was used to assess clinical significance. In all, 17 (33%) of the patients had clinical stage T1c disease. In our categorization mode, 88% of the T1c tumors fit the criteria for clinically significant tumors. T1c tumors, however, were significantly smaller (P < 0.01) and were more likely to be organ-confined (P = 0.01) as compared with non-T1c tumors in patients with an elevated preoperative serum PSA level. In contrast, tumors detected at preoperative PSA levels of < 4 ng/ml had comparably the lowest pathologic stages and tumor volumes in our series. In our categorization model, 42% of these tumors fit the criteria for minimal tumor. This group of radical prostatectomies was therefore most likely to harbor clinically insignificant cancer, a finding that was consistent in two other categorization models derived from earlier reports. T1c tumors comprise a large fraction of the tumors found in population-based screening. As judged by their pathologic characteristics. T1c tumors are clinically significant tumors. The overall low pathologic stage and Gleason score of these tumors make these patients excellent candidates for curative treatment by radical prostatectomy or radiotherapy. In contrast, some concern should be raised on the detection of tumors at low serum PSA levels by means of digital rectal examination and transrectal ultrasound alone, since a substantial proportion of these tumors could be considered clinically insignificant. Long-term follow-up, however, is necessary to substantiate this view.
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PMID:Comparison of pathologic characteristics of T1c and non-T1c cancers detected in a population-based screening study, the European Randomized Study of Screening for Prostate Cancer. 943 83

The objective was to devise local guidelines for the referral of patients with suspected prostatic carcinoma following evaluation by a retrospective audit of the value of the prostate-specific antigen concentration, together with age, urological symptoms, and digital rectal examination in the diagnosis of carcinoma of the prostate. Relevant details were collected from the notes of 582 patients from general practice and hospital. The significant diagnostic factors were ascertained by stepwise logistic regression. Prostate-specific antigen concentration, digital rectal examination and significant terminal dribbling were the most powerful factors in the diagnosis of carcinoma of the prostate. When prostate-specific antigen concentration was considered in isolation, a value of 6.5 ng/ml appeared appropriate for referral. Age was not significant, perhaps due to the narrow patient age range. The significant diagnostic factors were built into an algorithm calculating the probability of carcinoma of the prostate. This algorithm, together with prostate-specific antigen concentration results and digital rectal examination findings, forms the basis of the referral guidelines and a subsequent prospective study.
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PMID:An audit of prostate-specific antigen and clinical symptoms in general practice. 953 83

Flutamide withdrawal syndrome is characterized by a decrease in prostate-specific antigen (PSA) after flutamide withdrawal in a subset of patients with progressing metastatic carcinoma of the prostate. It is generally hypothesized to be due to a point mutation in the androgen receptor that allows the antiandrogen to function as an agonist, leading to a dramatic and rapid PSA response. We describe a patient with androgen-independent prostate cancer in whom PSA continued to decrease for a period of 15 months after flutamide withdrawal. With continuing fall in PSA, the patient had unequivocal progression of disease seen on bone scan. This case illustrates the potential decoupling of PSA response from disease status in flutamide withdrawal. It also illustrates the need for continued clinical evaluation of patients with metastatic prostate cancer, even in the face of PSA response.
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PMID:Prolonged prostate-specific antigen response in flutamide withdrawal syndrome despite disease progression. 963 22

A 75-year-old man with carcinoma of the prostate presented with a pruritic, erythematous plaque involving the scrotal skin. Histological examination revealed extramammary Paget's disease. The intraepidermal tumour cells expressed prostate-specific antigen in keeping with a prostatic origin.
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PMID:Paget's disease of the scrotum: a case exhibiting positive prostate-specific antigen staining and associated prostatic adenocarcinoma. 964 Mar 81

Because a significant number of patients with pathologically organ-confined carcinoma of the prostate subsequently develop recurrent disease, metastasis may occur much earlier than previously believed. We have used a reverse transcription-PCR assay for prostate-specific antigen mRNA and an immunocytochemical staining method for cytokeratins to test this hypothesis in paired peripheral blood (PB) and bone marrow (BM) specimens from 71 patients with clinically localized disease before radical prostatectomy, 14 patients with advanced-stage carcinoma of the prostate, and 30 controls (young healthy volunteers, patients without prostate disease, and patients with benign prostatic hyperplasia). Controls were negative in BM and PB. Fifty-six% of patients with organ-confined tumors (pT2) and 73% of those with extracapsular extension (pT3) were positive in the BM versus 16% of those with pT2 tumors and 27% of those with pT3 tumors in the PB. Patients with advanced-stage disease were positive in 86% of BM versus 71% of PB. The sensitivity of the immunocytochemistry assay to detect tumor cells was lower as compared with the reverse transcription-PCR assay. The results suggest that tumor cell dissemination occurs early during disease progression. Prostate cells seem to preferentially concentrate in the BM rather than the PB, which may be due to sequestration there by homing mechanisms. As the rate of detection in the BM exceeds the proportion of patients with subsequently progressing disease, we hypothesize that only a subset of these cells can survive in the BM and evolve to clinically apparent disease.
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PMID:Early tumor cell dissemination in patients with clinically localized carcinoma of the prostate. 981 80

Prostatic carcinoma has proven extremely difficult to establish as cell lines or xenografts. In this article, we describe a new series of prostate cancer xenografts propagated in athymic mice, designated LuCaP 23, developed from prostate metastases harvested at autopsy shortly after death. Tumor from three separate metastatic deposits was developed into three xenograft sublines: two from lymph node metastases (LuCaP 23.1 and 23.8) and one from a liver metastasis (LuCaP 23.12). Fluorescence in situ hybridization analysis confirms the xenografts are human. Histologically, the xenografts are comprised of columnar epithelial cells arranged in a glandular pattern. Tumor doubling times range from 11 to 21 days for the three sublines. The cells secrete large amounts of prostate-specific antigen (PSA) with PSA indices of 1.27, 1.63, and 5.21 ng/ml/mm3 for the mice bearing the LuCaP 23.1, 23.8, and 23.12 sublines, respectively. Following androgen deprivation a temporary decrease in PSA secretion and a decrease in tumor size are noted in most tumors. Eventually, the tumors become androgen independent and resume growth in castrate hosts. The degree of PSA response to castration and time to PSA nadir correlate with time to progression. Thus, unlike most existing models of prostatic carcinoma, this novel xenograft exhibits many phenotypic characteristics of clinical prostatic carcinoma, including androgen sensitivity. These properties make this xenograft an excellent model for future study.
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PMID:Characterization of a novel androgen-sensitive, prostate-specific antigen-producing prostatic carcinoma xenograft: LuCaP 23. 981 65

The Prostate Cancer Prevention Trial is an intergroup effort in the USA managed by the Southwest Oncology Group (SWOG) in collaboration with the Eastern Cooperative Oncology Group (ECOG) and the Cancer and Leukemia Group B (CALGB). This 10-year study began approximately 5 years ago and will achieve its primary endpoint in October 2004. At the start of the study, 18,882 men, aged over 55 years, and with normal digital rectal examination (DRE) and serum prostate-specific antigen (PSA) levels of </=3.0 ng/ml were randomized to take finasteride (5 mg/day) or placebo (1 tablet/day). DRE and PSA have been determined yearly (PSA in a central laboratory). When DRE is abnormal or PSA rises to >4.0 ng/ml, a biopsy is recommended. Because of the effect finasteride has on PSA, the PSA value has been indexed to equalize the number of biopsies in both arms. At 7 years all survivors will undergo a sextant biopsy to determine the period prevalence of prostate cancer. The critical assumptions are: (1) finasteride-induced PSA changes result in a simple downward shift; (2) the assessment of adherence is sensitive enough to detect nonadherence affecting PSA level interpretation: (3) factors affecting biopsy loss will be equal in both arms; (4) finasteride does not affect the sensitivity or specificity of DRE on transrectal ultrasound nor the sensitivity of biopsy; (5) bias resulting from transurethral resection of the prostate in benign prostate hyperplasia cases will be negligible.
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PMID:Prostate Cancer Prevention Trial (PCPT) update. 1032 20

Vaccine therapy may provide an alternative for prostate cancer patients whose disease no longer responds to hormone therapy. Administration of dendritic cells pulsed with prostate-specific membrane antigen (PSMA) induces cellular immune responses against the tumor with virtually no adverse effects. About 30% of the evaluable patients were identified as partial responders, based on the National Prostate Cancer Project (NPCP) criteria. In addition, there was a 50% decrease of serum prostate-specific antigen or resolution of previously measurable lesions on imaging. Dendritic cell vaccine therapy may have a synergistic effect, when combined with other therapies.
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PMID:Vaccine therapy for prostate cancer. 1036 59

To investigate the histogenesis of undifferentiated carcinoma of the prostate with small cell features we analysed the expression of neuroendocrine (NE) markers, the androgen receptor (AR), and prostate-specific antigen (PSA) in 19 undifferentiated carcinomas of the prostate. The proliferative activity (MIB-1/Ki67) of the tumours was examined, and the clinical data reviewed. The results identified two groups: carcinomas in group 1 were positive for PSA and AR and negative for NE markers. The mean MIB-1 labelling index (LI) was 34.8% and the mean serum PSA value 56.4 ng/ml. Two of the 7 patients died within 12 months after tumour diagnosis. The tumours in group 2 were NE differentiated small cell carcinomas (SCC), which were negative for PSA and AR. The mean MIB-1 LI was 82.6% and the mean serum PSA value 7.1 ng/ml. Seven of the 10 patients died between 2 and 12 months after tumour diagnosis. Positive staining for NE markers in combination with negative staining for PSA and AR and a high MIB-1 LI substantiated the diagnosis of a NE-SCC. We suggest that this tumour has a stem cell origin and does not derive from a dedifferentiated adenocarcinoma or from benign NE cells of the prostatic epithelium. This clear distinction of NE-SCC from NE-negative undifferentiated carcinoma is in accordance with the differing biological behaviour and response to therapy of the two tumour entities.
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PMID:Undifferentiated carcinoma of the prostate with small cell features: immunohistochemical subtyping and reflections on histogenesis. 1038 21

A randomized screening trial was started in Europe to show the effect of early detection and treatment of prostate cancer on mortality (European Study on Screening of Prostate Cancer). In one centre (Rotterdam), the screening protocol initially consisted of 3 screening tests for all men: prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasonography (TRUS). A PSA value of >/=4 ng/ml and/or an abnormality on DRE and/or TRUS were taken to indicate that biopsy was required. In this study, we examined the possibilities for a more efficient screening protocol. A logistic-regression model was used to predict the number of cancers for PSA < 4 ng/ml if all men were biopsied (predictive index, PI). Effects of a change in PSA cut-off on the screening results were explored. Weights were applied to procedures and cancers to explore the possibility of expressing differences between protocols in one overall figure. Biopsies in men with PSA < 1 ng/ml and a positive DRE or TRUS were very inefficient. Applying DRE and TRUS only in the PSA ranges 1.5 to 3.9 and 2 to 3.9 ng/ml to determine whether a biopsy was required would result in a decrease of 29 to 36% in biopsies and a decrease of 5 to 8% in cancers. However, the results of DRE and TRUS could not be duplicated entirely. A protocol with only PSA >/= 3 ng/ml as a direct biopsy indicator resulted in a decrease of detected cancers by 7.6% and of biopsies by 12%, also a much simpler screening procedure. Use of the PI would give more efficient protocols, but this should be viewed as a preliminary finding, with the disadvantage of necessitating many additional screening visits. Since the results of DRE and TRUS could not be duplicated, a change in protocol towards PSA >/= 3 ng/ml appears acceptable. If this proves effective, a final judgement about the optimal combination of screening tests may be made. Int. J. Cancer (Pred. Oncol.) 84:437-441, 1999.
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PMID:Changing role of 3 screening modalities in the European randomized study of screening for prostate cancer (Rotterdam). 1040


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