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R E Greenberg

Publications and source records attributed to R E Greenberg.

At least 19 recordsLinked to original sources
PubMed2004

Prevalence and patterns of self-initiated nutritional supplementation in men at high risk of prostate cancer.

OBJECTIVE: To define the prevalence and patterns of self-initiated herbal and vitamin supplementation among men at high risk of developing prostate cancer, as there is increasing public awareness of prostate cancer screening, risk-factor assessment and prevention, leading to increasing interest in the use and systematic study of nutritional therapies for prostate cancer prevention. SUBJECTS AND METHODS: Since 1996 our institution has prospectively maintained a prostate cancer-risk registry through its Prostate Cancer Risk Assessment Program (PRAP). Eligibility includes African-American men, any man with at least one first-degree relative or two or more second-degree relatives with prostate cancer, or men who tested positively for the BRCA1 gene mutation. A 420-item self-administered questionnaire was completed and included the use of nutritional supplements and complementary therapies. We divided men into groups who used supplements to lessen their cancer risk and those who did not. The prevalence and patterns of use were evaluated and the two groups then compared for differences in demographic, socio-economic and risk-perception variables. RESULTS: In all, 345 high-risk men were enrolled in the PRAP over a 5-year period. Data on the use of dietary or herbal supplements were available on 333 men (97%), of whom over half (170) reported taking one or more supplements to prevent prostate cancer. Supplement use was divided into eight categories, including vitamins, minerals, extracts from fruits/seeds, organic compounds, flowers/bulbs, leaves/bark, roots, or animal products. Most commonly used for self-initiated chemoprevention were vitamins (95%), minerals (28%), and fruit/seed extracts (18%). More than a quarter of men (27%) took three or more agents. Men taking proactive preventative measures were statistically more likely to be Caucasian and aged > 60 years (P < 0.05). African-Americans were less likely to self-initiate preventative steps. Men taking supplements tended to return more often for follow-up and participate in PRAP longer, while those not taking supplements tended to earn less and report less self-perceived risk. CONCLUSIONS: A significant proportion of men at risk of developing prostate cancer initiate measures they perceive to reduce their risk. Although the chemopreventative efficacy of many of these supplements remains unsubstantiated, they are widely perceived by the public to reduce the risk of developing prostate cancer. These data provide an insight into patient perceptions and misconceptions of chemopreventative strategies, and may help to refine recruitment efforts in multi-institutional prostate cancer prevention trials.

Adult↗
PubMed2001

Loss of the short arm of the Y chromosome in human prostate carcinoma.

A change in Y chromosome number is one of the many cytogenetic abnormalities reported in human prostate tumors. However, reports in the literature have varied regarding the frequency of Y loss or gain and the significance of Y aneusomy with respect to the biology of the disease. We have conducted an analysis of the Y chromosome in malignant and benign hyperplastic human prostate epithelium in order to determine whether regional Y loss occurs in prostate cancer. To accomplish this we performed dual-color fluorescence in situ hybridization (FISH) on serial sections of paraffin-embedded prostate tumor tissues using either a Yp (SRY), Ycen (alpha-satellite) or Yq (satellite 3) probe, and an Xcen (alpha-satellite) probe that served as a control for hybridization and nuclear truncation. The results of our FISH analysis demonstrated loss of Yp in the malignant epithelium of 14/40 (35%) prostate tumor sections examined. We also found loss of Yq in 4/40 (10%) of the samples, with one of these exhibiting accompanying Yp loss. The remaining samples, 23/40 (58%), retained both Yp and Yq markers, with no evidence of either Ycen loss or Y gain in any of the tumor samples examined. In addition, Y loss was detected in the benign hyperplastic regions in nearly one-half of the tissue sections that exhibited Y loss in the malignant epithelium. These results demonstrate that regional chromosome Y loss occurs in prostate cancer, that loss of Yp is the most frequent event, and suggest that this loss may in some cases be a precursor to prostate malignancy.

Adult↗
PubMed2001

Increased hypoxia correlates with increased expression of the angiogenesis marker vascular endothelial growth factor in human prostate cancer.

OBJECTIVES: To test the hypothesis that increasing levels of hypoxia are associated with increased expression of vascular endothelial growth factor (VEGF) in prostate cancer by correlating the level of median tissue oxygenation in human prostate tumors with the immunohistochemically determined level of VEGF expression. METHODS: Custom-made Eppendorf oxygen microelectrodes were used to quantitate the pO(2) levels in prostate tumors of 13 men undergoing radical prostatectomy. All pO(2) measurements were performed under fluorine-based general anesthesia. Paraffin-embedded tumor tissue from these men was analyzed to measure the level of VEGF expression by immunohistochemical staining. The significance of the associations between the pO(2) levels and VEGF staining were determined by the Pearson correlations. RESULTS: The range of the median pO(2) levels (based on between 97 and 129 individual measurements) among 13 prostate tumors was 0.5 to 44.9 mm Hg. The blinded comparison of pO(2) levels and VEGF staining intensity demonstrated a significant correlation between increasing hypoxia and the percentage of cells staining positive for VEGF (r = -0.721, P = 0.005). This correlation was also significant when pO(2) levels were compared with the overall immunoreactive score, which takes into account staining intensity (r = -0.642, P = 0.018). CONCLUSIONS: To our knowledge, this is the first study demonstrating a significant association between increasing levels of hypoxia and increased expression of the angiogenesis marker VEGF in human prostate carcinoma. The results of our study further support the exploration of antiangiogenesis strategies for the treatment of human prostate cancer.

Adult↗
PubMed2001

Hypoxia in human prostate carcinoma: an Eppendorf PO2 study.

The purpose of this study was to characterize the extent of hypoxia in human prostate carcinoma using the Eppendorf PO2 microelectrode. Custom-made Eppendorf PO2 microelectrodes were used to obtain PO2 measurements from the pathologically involved region of the prostate (as determined by the pretreatment sextant biopsies), as well as from a region of normal muscle for comparison. Fifty-nine patients with localized prostate cancer were studied, all of whom received brachytherapy implants under spinal anesthesia. A multivariate mixed effects analysis for prediction of tumor oxygenation was performed including the following covariates: type of tissue (prostate versus muscle), prostatic-specific antigen, disease stage, patient age and race, tumor grade, volume, perineural invasion, and hormonal therapy. Because of differences in patient characteristics, control measurements were obtained from normal muscle in all patients. This internal comparison showed that the oxygen measurements from the pathologically involved portion of the prostate were significantly lower (average median PO2 = 2.4 mm Hg) compared with the measurements from normal muscle (average median PO2 = 30.0 mm Hg), p < 0.0001. A multivariate, linear, mixed analysis demonstrated that the only significant predictor of oxygenation was the type of tissue (prostate versus muscle). This study, using in vivo electrode oxygen measurements, suggests that hypoxia exists in human prostate carcinoma. More patients will be accrued to this study to ultimately correlate the oxygenation status in prostate carcinoma tumors with treatment outcome.

Aged↗
PubMed2001

Maintenance therapy for superficial bladder cancer.

Transurethral resection remains the standard for first-line treatment of transitional cell carcinoma of the bladder. This technique clearly defines the pathologic grade and is essential in determining the clinical stage of the bladder tumor. Intravesical therapy is an important adjunct to transurethral resection in the management of patients with superficial bladder cancer, many of whom are at risk for disease recurrence and progression. Pharmacotherapy consisting of cytotoxic and immunomodulating agents has demonstrated utility against superficial transitional cell carcinoma. Bacillus Calmette-Guérin and mitomycin (Mutamycin) remain the more commonly used and most effective agents in the prophylaxis against recurrence and progression of superficial bladder transitional cell carcinoma. Many studies have examined their efficacy at different schedules. This article reviews the traditional intravesical agents that are useful in the therapy and prophylaxis of superficial transitional cell carcinoma of the bladder. It also addresses their long-term efficacy when used as maintenance therapy in higher-risk patients.

Antibiotics, Antineoplastic↗
PubMed2000

Increasing levels of hypoxia in prostate carcinoma correlate significantly with increasing clinical stage and patient age: an Eppendorf pO(2) study.

BACKGROUND: The purpose of this study was to analyze the extent of hypoxia in prostate carcinoma tumors using the Eppendorf pO(2) microelectrode and correlate this with pretreatment characteristics and prognostic factors. METHODS: Custom-made Eppendorf pO(2) microelectrodes were used to obtain pO(2) measurements from the pathologically involved region of the prostate (as determined by the pretreatment sextant biopsies) as well as from a region of normal muscle for comparison. Each set of measurements comprised approximately 100 separate readings of pO(2), for a total of 10,804 individual measurements. Fifty-five patients with localized prostate carcinoma were studied: Forty-one patients received brachytherapy implants, and 14 patients underwent radical prostatectomy. The pO(2) measurements were obtained in the operating room by using a sterile technique under spinal anesthesia for the brachytherapy group and under general anesthesia for the surgery group. The Eppendorf histograms were recorded and described by the median pO(2), mean pO(2), and percentage < 5 mm Hg and < 10 mm Hg. A multivariate mixed-effects analysis for the prediction of tumor oxygenation was performed and included the following covariates: type of tissue (prostate vs. muscle), type of treatment (implant vs. surgery) and/or anesthesia (spinal vs. general), prostate specific antigen level, disease stage, patient age and race, tumor grade, tumor volume, perineural invasion, and hormonal therapy. RESULTS: Due to differences in patient characteristics and the anesthesia employed, control measurements were obtained from normal muscle (in all but two patients). This internal comparison showed that the oxygen measurements from the pathologically involved portion of the prostate were significantly lower (average median pO(2), 9.9 mm Hg) compared with the measurements normal muscle (average median pO(2), 28.6 mm Hg; P < 0.0001). A multivariate, linear, mixed analysis demonstrated that, among all of the patients, the significant predictors of oxygenation were tissue (prostate vs. muscle) and anesthesia (spinal vs. general) or treatment (implant vs. surgery). Among the brachytherapy (spinal anesthesia) patients, the significant predictors of pO(2) were tissue type, disease stage, and patient age. There were no significant predictors of oxygenation in the surgical (general anesthesia) group. CONCLUSIONS: This study, employing in vivo electrode oxygen measurements, demonstrated that hypoxia exists in prostate carcinoma tumors. A dramatic effect of anesthesia was observed, likely due to modulation of polarography in the presence of fluorine. Within the group of brachytherapy (spinal anesthesia) patients, increasing levels of hypoxia (within prostatic tissue) correlated significantly with increasing clinical stage and patient age. More patients will be accrued to this prospective study to further correlate the oxygenation status in prostate carcinoma tumors with known prognostic factors and, ultimately, treatment outcome.

Age Factors↗
PubMed2000

Pilot study of the tolerability and toxicity of intravesical valrubicin immediately after transurethral resection of superficial bladder cancer.

OBJECTIVES: To assess in a pilot study the safety, tolerability, and technical feasibility of administering intravesical valrubicin immediately after transurethral resection of bladder tumors (TURBT) in patients with superficial bladder cancer and to evaluate the optimal dose of valrubicin and its systemic absorption. METHODS: Twenty-two patients with recurrent or newly diagnosed Stage Ta or T1 transitional cell tumors received a single dose of 400 mg, 600 mg, or 800 mg of intravesical valrubicin immediately after TURBT. Four patients thought to be at high risk of recurrence were followed up with five additional doses of 800 mg valrubicin, given weekly. RESULTS: The use of valrubicin after TURBT was generally well tolerated. Little evidence was found to suggest a direct relationship among the dose of valrubicin, the time between the end of TURBT and drug instillation, and the occurrence of most bladder symptoms. The most commonly reported adverse events included dysuria (77%), hematuria (59%), and urgency/frequency (23%). Pharmacokinetic analyses revealed that the mean systemic exposure to valrubicin and its metabolites depended on the extent of the TURBT and the damage to the bladder wall. CONCLUSIONS: The results of this study indicated that administration of valrubicin immediately after TURBT is feasible.

Administration, Intravesical↗
PubMed2000

Intravesical therapy for superficial bladder cancer.

Approximately 54,400 new cases of transitional cell carcinoma of the bladder were reported in the United States in 1999, with an estimated 12,500 deaths attributable to this cancer. Close to 75% of all bladder tumors are confined to the urothelium (stage Ta, or carcinoma in situ), and nearly 30% of papillary tumors invade the lamina propria (stage T1). The majority of superficial tumors are low grade with low rates of progression. Transurethral resection is the standard initial treatment for transitional cell carcinoma. Intravesical therapy is an important adjunct to transurethral resection in patients with superficial bladder cancer, many of whom are at risk for disease recurrence and progression. Cytotoxic and immunomodulating agents and, more recently, photosensitizers have demonstrated utility against superficial transitional cell carcinoma. Many studies have assessed and continue to examine the efficacy of various agents at different doses and in different combinations and schedules. Recently, valrubicin (Valstar) won Food and Drug Administration (FDA) approval only for the treatment of refractory carcinoma in situ. However, bacillus Calmette-Guérin (BCG) and mitomycin (Mutamycin) remain the most commonly used, most effective agents available for prophylaxis against recurrence and subsequent progression of superficial bladder cancer. This article reviews traditional and alternative intravesical agents useful in the therapy and prophylaxis of superficial transitional cell carcinoma of the bladder.

Adjuvants, Immunologic↗
PubMed1999

Hypoxic regions exist in human prostate carcinoma.

OBJECTIVES: The purpose of this study was to characterize, by use of the Eppendorf microelectrode, the extent of hypoxia (range/heterogeneity) in human prostate carcinomas. METHODS: Custom-made Eppendorf pO2 microelectrodes were used to obtain PO2 measurements from the pathologically involved side of the prostate, as well as from a region of normal muscle for comparison. Each set of measurements comprised approximately 100 separate readings of pO2, for a total of 2145 individual measurements. Twelve patients were studied, 7 of whom underwent brachytherapy, 3 a radical prostatectomy, and 2 a cystoprostatectomy. The pO2 measurements were obtained in the operating room, using sterile technique, under spinal anesthesia for the brachytherapy group patients and under general anesthesia for the surgery group patients. The Eppendorf histograms were recorded and described by the median pO2, mean pO2, and percentage of measurements less than 5 mm Hg and less than 10 mm Hg. RESULTS: Because of differences in patient characteristics and the anesthesia employed, control measurements were obtained from nearby normal muscle as an internal control in all but 2 patients. This internal comparison showed that the oxygen measurements from the pathologically involved portion of the prostate were significantly lower than those from normal muscle. Similarly, higher pO2 readings were obtained from the pathologically normal prostates (in the patients with bladder cancer) than from the prostates of patients with prostate carcinoma. Increasing levels of hypoxia were observed with increasing clinical stage. Significant predictors of oxygenation include the type of tissue (pathologically involved prostate versus normal muscle or normal prostate), clinical stage, and type of anesthesia. CONCLUSIONS: This report, to our knowledge, represents the first study to obtain in vivo electrode measurements of oxygen levels in patients with prostate cancer and suggests that hypoxic regions exist in human prostate carcinoma. More patients will be accrued to this prospective study to correlate the oxygenation status of prostate carcinoma with known prognostic factors and treatment outcome.

Adult↗
PubMed1997

Adenocarcinoma in a duplicated bladder.

We report a rare case of duplication of the bladder, urethra, uterus, vagina, and associated anomalies in a woman. As an infant, she initially underwent successful surgical reconstruction. As an adult, she developed adenocarcinoma within the defunctionalized bladder moiety. The surgical management and pathology of this cancer are detailed and the pertinent literature reviewed.

Abnormalities, Multiple↗
PubMed1997

Initial report on intravesical administration of N-trifluoroacetyladriamycin-14-valerate (AD 32) to patients with refractory superficial transitional cell carcinoma of the urinary bladder.

OBJECTIVES: This study was designed to assess the pharmacokinetics, safety, and antitumor activity of intravesically administered AD 32, a novel anthracycline, in patients with transitional cell carcinoma (TCC) of the bladder. METHODS: Six weekly doses of AD 32 (200 to 900 mg) were administered to 32 patients with superficial TCC who were candidates for intravesical treatment. Serum drug levels were measured during the 6-hour period after administration of the first, third, and sixth doses. Patients underwent bladder evaluations at 3-month intervals to determine responses to treatment. RESULTS: Very low levels of unmetabolized AD 32 and its two primary metabolites were measured in serum. The lack of systemic exposure was confirmed by the finding of only a few minor systemic adverse events. Local bladder irritation, the main toxicity associated with intravesical administration of AD 32, persisted for several days after each instillation. The maximum tolerated dose was 800 mg. Thirteen patients had complete responses to treatment, including 8 who remained disease free for 12.1 to 38.5 months. CONCLUSIONS: AD 32 is an active drug for the treatment of superficial bladder cancer. Further studies of intravesical administration of AD 32 are warranted.

Administration, Intravesical↗
PubMed1997

The staging pelvic lymphadenectomy: implications as an adjunctive procedure for clinically localized prostate cancer.

OBJECTIVES: To evaluate the utility of staging pelvic lymphadenectomy and to identify factors associated with nodal metastases in which a node dissection would be of clinical benefit. PATIENTS AND METHODS: A retrospective analysis (1989-1993) was performed on 303 consecutive patients who underwent staging bilateral modified pelvic lymph node dissection for clinically localized prostate cancer. Multivariate logistic regression analysis was used to evaluate age, race, clinical stage, prostate-specific antigen (PSA) level and Gleason score for predicting nodal metastases. RESULTS: Twenty-eight patients had nodal metastases, giving an overall prevalence of 9.2%. PSA and Gleason score (both P < 0.001) were significantly predictive of nodal involvement when combined or as independent variables. Relative to PSA and Gleason score, the patients' age, race and clinical stage were less relevant. Sensitivity analysis determined that combining a PSA of > or = 20 ng/mL (normal 0-4) and a Gleason score of > or = 8 gave a negative predictive value of 92% with a specificity of 99%, a positive predictive value of 67% and an overall accuracy of 91% for predicting nodal metastases. CONCLUSION: From this data, lymph node metastases are unlikely in patients with clinically localized prostate cancer who have a PSA of < 20 ng/mL and a Gleason score < 8, and that a pelvic lymph node dissection as an adjunctive procedure should be avoided in such individuals.

Humans↗
PubMed1996

Leiomyosarcoma of the renal vein.

The preoperative diagnosis for primary leiomyosarcoma of the renal vein, an extremely rare tumor, is difficult. The tumor predominantly occurs in women and on the left side. Its natural history is toward distant metastases and a poor 5-year survival rate. Nephrectomy and en-bloc surgical resection remain the mainstay of therapy. We present three such cases and review the world literature.

Adult↗
PubMed1996

Loss of heterozygosity studies indicate that chromosome arm 1p harbors a tumor supressor gene for renal oncocytomas.

We carried out a complete genome scan for loss of heterozygosity (LOH) in four renal oncocytomas by using highly polymorphic CA repeat microsatellite loci. Three of the four tumors exhibited LOH for chromosome arm 1p, and the oncocytomas of both female patients lost Xq. Therefore, these chromosome arms may harbor tumor suppressor genes involved in the etiology of this disease. Although the genomes of ontocytomas are relatively stable, two different microsatellite loci in one tumor were mutated by + or - 2 nt. Similar alterations in CA repeats that are probably due to spontaneous mutation have been observed in renal cell carcinomas.

Adenoma, Oxyphilic↗
PubMed1995

Genomic alterations and instabilities in renal cell carcinomas and their relationship to tumor pathology.

A comprehensive genome scan for loss of heterozygosity (LOH) in 33 renal cell carcinomas indicates that mutations of tumor suppressor genes on several different chromosomes are required for malignant transformation in this disease. In the case of nonpapillary renal carcinomas chromosomes 3p, 6q, 8p, 9pq, and 14q exhibit elevated levels of LOH. Although 3p is the most frequently lost chromosome arm, in no case is 3p observed as the sole allelic loss because it always occurs in conjunction with the loss of either 6q, 8p, or 14q. This result indicates that the mutation of a tumor suppressor gene on 3p, most likely von Hippel-Lindau disease (VHL), may be necessary but is not sufficient for the development of nonpapillary renal cell carcinoma. In papillary renal tumors, LOH is observed most often for chromosomes 6pq, 9p, 11q, 14q, and 21q. This suggests that tumor suppressor genes located on chromosomes 6q, 9pq, and 14q may be involved in the development and/or progression of both nonpapillary and papillary renal cell carcinomas. However, LOH in papillary tumors appears to be especially elevated for 11q and 21q and reduced for 3p and 8p indicating that there are also tumor suppressor genes specific to each form of the disease. There is no correlation between stage of disease and the extent of LOH, loss of a particular chromosome, or the number of chromosomes that show allele imbalance. Early and late stage tumors may exhibit either extensive LOH or no apparent allele loss; similarly, allelic imbalances are observed in both early and late stage renal cell carcinomas. This suggests that a gene (or genes) regulating mitotic chromosome stability may be mutated in some renal tumors. Preliminary evidence points to an association between genome instability and LOH of 14q. Finally, a distinct type of microsatellite instability has been detected in 21% of renal cell carcinomas and occurs at a frequency of 4.4 x 10(-4)/locus. The most common mutation is a 2-bp insertion in a CA repeat. This alteration is not restricted to a particular histopathology or clinical stage, and it is not associated with allelic loss of a specific chromosome. The frequency of this event is similar to that which occurs spontaneously in germline microsatellite loci and is probably not the result of a defect in a mismatch repair gene. It is possible that this type of microsatellite instability is general and may occur in most, if not all, carcinomas.

Alleles↗
PubMed1995

Comprehensive allelotyping of human renal cell carcinomas using microsatellite DNA probes.

The von Hippel-Lindau locus on chromosome 3p is a tumor suppressor gene known to be involved in nonpapillary renal cell carcinoma. A previous loss of heterozygosity (LOH) study aimed at determining the allelotype of kidney tumors has indicated that in addition to 3p, chromosome arms 5q, 6q, 10q, 11q, 17p, and 19p may also harbor tumor suppressor genes. However, cytogenetic studies reveal that chromosomes 3p, 6q, 8p, 9pq, and 14q most frequently undergo karyotypic changes in renal tumors. To resolve these differences, a collection of microsatellite DNA probes has been used to scan for LOH so that 90% of individual tumor genomes were rendered informative for allele loss. The assay is capable of detecting quantitative genomic alterations in tumor cells as well. We find that LOH is most frequent for chromosome arm 3p. However, in no tumor is 3p exclusively affected. LOH for 6q, 8p, 9pq, and 14q is also distinctly elevated for both nonpapillary as well as papillary tumors and suggest that many of the tumor suppressor loci involved may be common to the etiology of both forms of kidney cancer.

Alleles↗