PubMed Health⌕ Search

Biomedical subjects

Y Fradet

Publications and source records attributed to Y Fradet.

At least 55 records · Page 3Linked to original sources
PubMed1997

Dietary energy and nutrients in relation to preclinical prostate cancer.

Previous studies of diet and prostate cancer have focused on advanced disease and have suggested a positive association with saturated fat intake. We report a study assessing the relationship between diet and preclinical prostate cancer. A total of 215 men with preclinical prostate cancer and 593 controls with no evidence of cancer participated in a case-control study conducted in Quebec City between October 1990 and May 1993. The study population comprised two groups: men treated surgically for benign prostatic hypertrophy and participants in a prostate cancer screening program. Trained nutritionists interviewed the participants on their usual diet using a diet history questionnaire. Odds ratios for prostate cancer associated with quartiles of dietary intake and P values for trend were estimated by logistic regression while controlling for age, education, group, and family history of prostate cancer. A positive association was observed between total energy intake and preclinical prostate cancer (p = 0.004). The odds ratios for prostate cancer increased with each quartile of energy intake: 1.00, 1.77, 1.90, and 2.67. After adjustment for energy, nutrients were not associated with prostate cancer. This study provides some evidence that total energy intake is related to preclinical prostate cancer and suggests that diet could be involved earlier than thought in the occurrence of prostate cancer.

Aged↗
PubMed1997

Tumor-associated antigens in normal mucosa of patients with superficial transitional cell carcinoma of the bladder.

PURPOSE: We identified premalignant lesions in tumor-surrounding histologically normal bladder mucosa from patients with superficial and muscle-invasive bladder cancer to look for "premalignant" lesions as the source of tumor recurrence. MATERIALS AND METHODS: Tumor-associated antigen expression in histologically normal bladder mucosa in 23 patients with superficial bladder cancer was studied. Histologically normal bladder specimens from 21 patients with muscle-invasive bladder cancer and from 30 prostatic cancer patients served as controls. Tumor-related antigens 486p 3/12, LBS8, 19A211 and M344 were mapped quantitatively with monoclonal antibodies and immunohistological techniques. RESULTS: Expression of all four bladder tumor-associated antigens was significantly enhanced and more than two antigens were expressed simultaneously in histologically normal mucosa from both bladder-cancer groups, compared with histologically normal bladder mucosa of prostatic carcinoma patients (p < 0.05). CONCLUSIONS: The results suggest the existence of early malignantly transformed cells in the benign-looking and morphologically normal bladder mucosa of superficial bladder carcinoma patients, which possibly is the source of recurrent bladder cancer. This approach models the mapping of histopathologic premalignant lesions of the bladder to predict risk.

Aged↗
PubMed1997

Diagnostic accuracy of urinary cytology, and deoxyribonucleic acid flow cytometry and cytology on bladder washings during followup for bladder tumors.

PURPOSE: We evaluated the diagnostic accuracy of cytology on urine and bladder washings, and deoxyribonucleic acid (DNA) flow cytometry on bladder washings compared to cystoscopy during followup for bladder tumors. MATERIALS AND METHODS: A cross-sectional analysis was performed on 166 patients with a history of bladder tumor for the initial visit when cytology and DNA flow cytometry results were available for urine and bladder washing samples. There were 114 bladder tumor events and 52 negative controls (normal cystoscopy). A prospective study was conducted among the 66 patients with no tumor detected by cystoscopy at the initial visit and for whom the 3 test results were available. The patients were followed from this visit until tumor recurrence or the end of the followup period. Cytological examination was considered positive only when interpreted as malignant. Suspicious examinations were considered negative for the purpose of our study. RESULTS: Sensitivity and specificity of urinary cytology were 59 and 85%, respectively. Sensitivity was increased to 66% using bladder washing cytology whereas specificity was moderately decreased to 83%. The sensitivity and specificity of DNA aneuploidy were 45 and 87%, respectively. Inclusion within the aneuploid category of hyperdiploid samples (defined as more than 7% of cells in the S + G2M phase) increased sensitivity to 77%, while specificity decreased to 42%. Kaplan-Meier analysis of tumor-free survival in patients initially free of bladder cancer at cystoscopy showed an inability of DNA flow cytometry to predict recurrence, whereas positive urine or bladder washing cytology predicted a shorter time to recurrence (log-rank test p <0.01). CONCLUSIONS: These results show that DNA flow cytometry and cytology on bladder washing samples add little information to that obtained from voided urine cytology.

Cross-Sectional Studies↗
PubMed1996

Efficacy and safety of finasteride therapy for benign prostatic hyperplasia: results of a 2-year randomized controlled trial (the PROSPECT study). PROscar Safety Plus Efficacy Canadian Two year Study.

OBJECTIVE: To evaluate the efficacy and safety of 2 years' treatment of moderate benign prostatic hyperplasia (BPH) with finasteride. DESIGN: Double-blind, parallel-group, placebo-controlled, multicentre, prospective randomized study. SETTING: Outpatient care in 28 centres across Canada. PARTICIPANTS: Men aged 45 to 80, in good health, with moderate BPH and no evidence of prostate cancer. A total of 613 men were entered into the study; 472 completed the 2 years of treatment. INTERVENTION: After 1 month of receiving a placebo (run-in period), patients were given either finasteride (5 mg/d) or a placebo for 2 years. OUTCOME MEASURES EFFICACY: changes from baseline in BPH symptom scores, maximum urinary flow rates and prostate volume. SAFETY: onset, course and resolution of all adverse events during the treatment period. RESULTS: In the efficacy analyses the mean BPH symptom scores decreased 2.1 points (from 15.8 to 13.7) in the finasteride group, as compared with a decrease of 0.7 points (from 16.6 to 15.9) in the placebo group (P < or = 0.01). The maximum urinary flow rate increased by a mean of 1.4 mL/s (from 11.1 to 12.5 mL/s) in the finasteride group, as compared with an increase of 0.3 mL/s (from 10.9 to 11.2 mL/s) in the placebo group (p < or = 0.01). The mean prostate volume decreased by 21% (from a mean volume of 44.1 cm3 at baseline) in the treatment group; it increased by 8.4% (from a mean volume of 45.8 cm3 at baseline) in the placebo group (p < or = 0.01). In the safety analysis, the proportion of patients who experienced any adverse event was similar in the two groups (81.0% in the treatment group and 81.2% in the placebo group). However, the incidence of adverse events related to sexual dysfunction were significantly higher in the finasteride group than in the placebo group (ejaculation disorder 7.7% v. 1.7% and impotence 15.8% v. 6.3%; p < or = 0.01 for both parameters). CONCLUSION: Finasteride is a well-tolerated and effective alternative to watchful waiting in the treatment of moderate BPH.

Aged↗
PubMed1996

MAUB is a new mucin antigen associated with bladder cancer.

The M344 tumor-associated antigen, expressed in 70% of superficial bladder tumors, is a sialylated carbohydrate present on a high molecular mass thiol-reducible secreted mucin, which we named MAUB for mucin antigen of the urinary bladder. Herein we studied the relationship between MAUB and other known mucins in the MGH-U3 bladder cancer line where MAUB expression is modulated by culture conditions. Northern blots, immunoradiometric assays, and Western blots showed that only MUC1 and MUC2 are expressed in this MAUB-positive cell line. MUC1 differs from MAUB by its molecular mass and its non-oligomeric nature, while MUC2 has similar molecular mass and response to culture conditions. However, in double determinant immunoradiometric assays, MAUB and MUC2 did not cross-react. Moreover, confocal microscopy showed different subcellular localization of the two antigens. Treatment of MGH-U3 cells with MUC2 antisense oligodeoxynucleotides resulted in decreased expression of MUC2 and increased expression of MAUB, ruling out the possibility that monoclonal antibody M344 recognizes a different glycosylated form of MUC2. In addition, we identified a tumor specimen expressing MAUB but no MUC2 antigen or mRNA. Together, these results suggest that there is expression of at least three mucins in MGH-U3 cells and that MAUB is a cancer-associated mucin distinct from those identified so far.

Animals↗
PubMed1996

Identification of a superficial bladder tumor-associated glycoform of the carcinoembryonic antigen by monoclonal antibody 19A211.

Monoclonal antibody (mAb) 19A211 identifies a superficial bladder cancer-associated sialylated epitope expressed on a heterogeneous group of glycoproteins. These glycoproteins consist of a series of cytoplasmic glycoproteins ranging from 90 to 140 kDa present in tumor cells and, at a lower level, in normal urothelial cells, and of a membrane glycoprotein of 200 kDa observed in tumor cells only. To further characterize this antigenic system, we took advantage of the high avidity of mAb 19A211 to produce a rabbit polyclonal antibody by immunizing with antigen bound to mAb 19A211 immunoaffinity beads. The resulting polyclonal antibody specifically reacts with the 200-kDa species and not with the other glycoproteins. The biochemical characterization of this 200-kDa tumor-associated antigen showed that it is highly glycosylated (more than 50% w/w) and is anchored to the membrane via a glycosyl phosphatidylinositol link; these properties are shared with the carcinoembryonic antigen (CEA). Further experiments showed reactivity of two mAbs directed against protein epitopes of CEA with the 200-kDa component of 19A211 antigen. However, in immunohistochemistry studies of 29 colon and 23 bladder tumor specimens, no correlation was observed between expression of 19A211 and CEA antigens. Moreover, in RIAs, the intensity of expression of the 19A211 carbohydrate epitope relative to a CEA protein epitope was found to be significantly lower with CEA purified from a colon cancer cell line compared to CEA from a bladder cancer cell line. On the basis of these results, we conclude that the 200-kDa component of 19A211 antigen is a CEA glycoform preferentially expressed by superficial bladder tumors.

Animals↗
PubMed1996

Toxicity of ribosome-inactivating proteins-containing immunotoxins to a human bladder carcinoma cell line.

Immunotoxins were prepared by linking the type 1 ribosome-inactivating proteins (RIP) momordin I, pokeweed antiviral protein from seeds (PAP-S) and saporin-S6 to the 48-127 monoclonal antibody (MAb) recognising a glycoprotein (gp54) expressed on all human bladder tumours tested and on human bladder carcinoma cell lines, in particular on the T24 cell line. T24 cells required a 2 hr contact with immunotoxins to ensure binding and endocytosis. A time course of exposure, followed by further incubation without the immunotoxins, showed that maximum inhibition of protein synthesis by T24 cells was reached after 2 hr of contact followed by 3 days without the immunotoxins. Under optimal conditions, 48-127/RIP immunotoxins at nanomolar concentrations inhibited by 50% protein synthesis of target T24 cells. No toxicity was observed if (i) target cells were treated with non-conjugated RIP, (ii) target cells were treated with momordin I- or PAP-S-containing immunotoxins made with an irrelevant antibody and (iii) a non-target cell line was treated with the same 2 RIP conjugated to 48-127 antibody. The in vitro selective toxicity of these immunotoxins encourages further studies in view of a possible use in clinical trials for the local therapy of human bladder carcinomas.

Humans↗
PubMed1996

Androgen receptor modulation in benign human prostatic tissue and prostatic adenocarcinoma during neoadjuvant endocrine combination therapy.

Modulation of androgen receptor (AR) expression during neoadjuvant endocrine therapy in human prostates of patients with localized prostate cancer was investigated by immunohistochemistry. In 8 of 15 untreated prostatectomy specimens, the majority of prostatic glandular cells displayed nuclear immunostaining for AR, whereas only 1 of 26 pretreated cases displayed a similar glandular AR expression. Expression of AR in the prostatic stromal compartment of nontreated cases proved to be quite heterogeneous, since 4 of the 15 (27%) examined specimens did not show stromal AR expression. After preoperative neoadjuvant therapy, this value was 68%, although this difference did not reach statistical significance. Prostatectomy specimens of the treated patients contained carcinomas with a higher Gleason score than those of untreated patients. AR expression in carcinomas of treated patients was diminished (P= 0.05), which may be attributed to their relatively lower differentiation grade. The data strongly suggest that neoadjuvant hormone therapy reduces AR expression by nonneoplastic prostatic glandular cells and carcinoma cells by a selective, but incomplete, elimination of AR-positive cells.

Adenocarcinoma↗
PubMed1996

Prognostic significance of nuclear DNA content and S-phase fraction by flow cytometry in primary papillary superficial bladder cancer.

This study is aimed at determining the usefulness of nuclear DNA content and S-phase fraction (SPF) to predict tumor recurrence in papillary superficial bladder cancer. Tumor DNA content and SPF were measured by flow cytometry on formalin-fixed, paraffin-embedded tissue from 199 newly diagnosed pTa/pT1 transitional cell carcinomas of patients enrolled into a multicenter prospective study from 1990 to 1992. The follow-up extended up to March 1994, and, at last follow-up, 122 (61.3%) patients have experienced at least one recurrence. After exclusion of 34 cases, whose coefficient of variation exceeded 8%, 131 (79.4%) tumors were diploid, and 34 (20.6%) were aneuploid. There was no association between tumor DNA content and time to first recurrence. Diploid tumors with low SPF (< 11%) tended to have a longer recurrence-free survival (RFS) than those with high SPF, but this difference did not reach statistical significance (P = .2833). SPF in aneuploid tumors did not add any new information. Aneuploidy was associated with higher stage (P < .001), poorer grade (P < .002), multifocality (P = .028), Her-2/neu (P = .021), and p53 (P = .033) expression. High SPF correlated with higher stage (P = .066) and higher grade (P = .025). This study shows that DNA-ploidy and SPF measured on a single superficial bladder cancer specimen are not predictive of tumor recurrence. The frequent multifocality of the disease may explain, in part, these findings.

Adult↗
PubMed1996

Optimized microvessel density analysis improves prediction of cancer stage from prostate needle biopsies.

OBJECTIVES: Clinical staging of prostate cancer is inaccurate, often with significant upstaging on final pathologic review. We previously demonstrated the ability to predict extraprostatic extension of cancer by use of the Gleason score and serum prostate-specific antigen (PSA) measurements. Herein we present an interim analysis of data from an ongoing multi-institutional study to determine the predictive power of an enhancement of microvessel density analysis in combination with Gleason score and serum PSA to predict extraprostatic extension. METHODS: We evaluated a total of 186 randomly selected biopsy samples and matched totally embedded radical prostatectomy samples with preoperative PSA concentrations and patient demographics. Gleason score and optimized microvessel density (OMVD) were determined from the needle biopsy samples; pathologic stage was verified by independent review of the radical prostatectomy samples. An automated digital image analysis system measured microvessel morphology and calculated the OMVD in the biopsy samples (Biostage; Bard Diagnostic Sciences, Seattle, Wash). RESULTS: Prediction of extraprostatic extension was increased significantly when OMVD analysis was added to Gleason score and serum PSA concentration (P = 0.003). CONCLUSIONS: Optimized microvessel density analysis significantly increases the ability to predict extraprostatic extension of cancer preoperatively when combined with Gleason score and serum PSA concentration. This method appears to be a useful tool that can assist with treatment decisions in selected patients.

Aged↗
PubMed1996

A multicenter, randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of terazosin in the treatment of benign prostatic hyperplasia.

OBJECTIVES: This study was designed to evaluate the safety and efficacy of the selective alpha 1-adrenoceptor blocker terazosin in the treatment of benign prostatic hyperplasia (BPH). METHODS: Two hundred twenty-four patients aged 50 to 80 years, who had a diagnosis of BPH based on medical history, physical examination, and digital palpation, were recruited from 11 different sites between January 1992 and January 1994. The study consisted of a screening phase, a placebo phase, a double-blind dose-titration phase, and a double-blind maintenance phase. RESULTS: Of the patients recruited, 164 entered the double-blind phase and of these 134 were evaluable. Only 11 patients withdrew because of an adverse event, 7 in the terazosin and 4 in the placebo group. Compared to placebo, terazosin significantly increased peak and mean urine flow rates without significantly affecting voided volume or postvoid residual volume. It significantly improved both the obstructive and irritative symptoms associated with BPH. Fifty-one patients from the terazosin group reported a total of 120 adverse events compared with 83 reported by 42 patients in the placebo group. The majority of these events were mild to moderate. Seventeen terazosin-treated patients reported hypotension-related adverse events and 4 withdrew from the study. However, concurrent treatment with antihypertensive agents did not affect the blood pressure response of the terazosin group. CONCLUSIONS: Overall, this study showed terazosin to be safe and effective in relieving the signs and symptoms of BPH and should be considered as a treatment alternative.

Adrenergic alpha-Antagonists↗
PubMed1996

The role of neoadjuvant androgen deprivation prior to radical prostatectomy.

Androgen ablation prior to radical prostatectomy currently is under investigation with the goal of improving cancer control in patients with clinically treated localized prostate cancer. Results of several randomized studies have shown a significant pathologic downstaging and a decrease in the rate of positive surgical margins using neoadjuvant therapy in stage B cancers. Despite theoretic advantages, neoadjuvant therapy may have side effects and is associated with costs. Until long-term results of biologic and clinical failure rates are available, this approach should be considered investigational.

Androgen Antagonists↗
PubMed1996

Effect of neoadjuvant endocrine therapy (combined androgen blockade) on normal prostate and prostatic carcinoma. A randomized study.

The morphologic changes induced by neoadjuvant combination endocrine therapy were evaluated in prostatectomy specimens from patients diagnosed with localized prostate cancer. These patients participated in a prospective, randomized clinical trial investigating the effect of 3 months of combination therapy with flutamide and an LHRH agonist prior to radical prostatectomy versus radical prostatectomy alone. Ninety-six radical prostatectomy specimens processed according to the same protocol were evaluated without knowledge of prior treatment. Forty-seven patients were randomly assigned to the neoadjuvant combination therapy group and 49 to the control arm. Compared with the control group, several changes were strongly and significantly associated with exposure to neoadjuvant combination therapy. The nonmalignant prostatic tissue showed strong prominence and hyperplasia of the basal cell layer, accompanied by epithelial cell vacuolization and markedly reduced occurrence of prostatic intraepithelial neoplasia (p < 0.001) after combination therapy. Prostate cancer tissue, on the other hand, showed smaller nucleoli (p < 0.001), cell vacuolization (p < 0.001), rare intraluminal crystalloids (p < 0.001), higher Gleason grade (p < 0.001), lower prevalence of capsular penetration (p < 0.001), and less frequent invasion of the perineural spaces (p < 0.001) and surgical margins (p = 0.002). Tumor volume, was also reduced by more than 40% in the treated group (p = 0.007). The present findings show that preoperative endocrine combination therapy induces highly characteristic changes in both nonmalignant and cancerous prostatic tissue. Furthermore, following endocrine treatment, the surgical margins are less likely to be involved by cancer and capsular penetration is reduced.

Adult↗
PubMed1996

Prevalence and clinical significance of HER/2neu, p53 and Rb expression in primary superficial bladder cancer.

PURPOSE: The usefulness of the expression of HER2/neu oncoprotein and of p53 and Rb suppressor gene product as predictors of tumor recurrence was evaluated by using a bank of prospectively collected primary papillary bladder tumors treated initially only by transurethral resection. MATERIALS AND METHODS: The expression of HER-2/neu oncoprotein and p53 and Rb suppressor genes was evaluated by immunohistochemistry in 256, 265 and 74 specimens of primary Ta/T1 superficial bladder tumors obtained from patients enrolled in a prospective study from 1990 to 1992. Survival analysis was used to evaluate the association between time to first recurrence and expression of each marker, the follow-up period extending to March 1994. Immunostaining for p53 and HER-2/neu was performed on paraffin-embedded tissue and, for Rb, on frozen tissue only. RESULTS: Her-2/neu was expressed in 21 (8.2%) cases and p53 in 39 cases (14.7%); Rb expression was altered in 12 (16.2%). In this study, p53 expression was only related to earlier recurrence in a univariate analysis. Multivariate analysis, however, failed to recognize p53 expression as an independent predictor of recurrence. CONCLUSIONS: Our study demonstrates the low prevalence of HER2/neu, p53 and altered Rb expression in superficial TCC at initial resection. Only p53 expression was significantly associated with an earlier first tumor recurrence, but this association was not independent of other prognostic factors.

Aged↗
PubMed1996

Randomized, prospective, controlled study comparing radical prostatectomy alone and neoadjuvant androgen withdrawal in the treatment of localized prostate cancer. Canadian Urologic Oncology Group.

PURPOSE: A prospective, multicenter, randomized study was done to test the hypothesis that neoadjuvant androgen withdrawal decreases the incidence of positive margins following radical prostatectomy for localized prostate cancer. MATERIALS AND METHODS: Observations were made of 213 patients randomized to undergo radical prostatectomy alone (101) or to receive a 12-week course of 300 mg. cyproterone acetate daily followed by surgery (112). Groups were similar at baseline in terms of clinical stage, serum prostate specific antigen and Gleason score. Of 192 patients available for efficacy analysis 9 had stage T1b, 8 stage T1c, 63 stage T2a, 36 stage T2b and 76 stage T2c disease. RESULTS: One or more positive surgical margins were found in 59 of 91 patients (64.8%) in the surgery only group compared to 28 of 101 (27.7%) in the cyproterone acetate group (p = 0.001). Patients who received preoperative therapy had a statistically significantly lower rate of apical margin involvement than those who did not (17.8 versus 47.8%, respectively, p < 0.0001). There was no statistically significant difference in surgical (p = 0.8645) or postoperative (p = 0.173) complications between the 2 groups. CONCLUSIONS: Neoadjuvant androgen withdrawal with a 12-week course of 300 mg. cyproterone acetate daily results in a lower rate of positive margins without adversely affecting postoperative recovery. The impact on patient survival will be determined by long-term followup.

Aged↗
PubMed1996

[Clinical value of the study of proliferation and cell activation antigens with flow cytometry in bladder cancer].

The proliferative rate of tumor cells is frequently proportional to their degree of aggressiveness. The objective of the present study was to determine the correlation between the expression of three antigens associated with proliferation and the stage and ploidy of bladder cancers. The reactivity of antibodies against the nuclear antigen Ki-67 and membrane antigens T43 and the epidermal growth factor receptor (EGFR) was studied by flow cytometry on a series of 35 clinical samples of superficial and infiltrating bladder cancer and as well as on 5 specimens of normal urothelial cells. A preferential expression of the T43 antigen was observed on invasive cancer. EGFR was less frequently expressed; however, seven of the nine positive samples were from invasive cancers. Ki67 on the other hand did not show any selective expression according to tumor stage. When comparing Ki-67 and T43 expression on individual tumor samples, a negative correlation was found in that no tumor strongly expressed both markers simultaneously. These results suggest that markers of proliferation and activation do not all measure the same tumor parameters. Together, they may provide prognostic information that may be useful in the follow-up of patients with bladder cancer.

Antigens, Surface↗
PubMed1995

Prognostic value of epidermal growth factor-receptor, T138 and T43 expression in bladder cancer.

Tumour-associated markers defined by monoclonal antibodies have proven useful to phenotype bladder tumours. In order to evaluate the prognostic value of such markers, we performed an immunohistochemical study on 57 transitional cell carcinomas (23 infiltrative and 34 superficial tumours) and ten healthy bladders using monoclonal antibodies against the external domain of the epidermal growth factor receptor (EGFR) and against the tumour-associated antigens T43, 19A211 and T138. Immunohistochemistry was performed on frozen sections using a two-step alkaline phosphatase method. The staining pattern obtained with each antibody was analysed according to the TNM classification, and results were analysed according to the subsequent clinical course. 19A211 preferentially stained superficial tumours, and T43, T138 and EGFR preferentially stained invasive tumours. Three monoclonal antibodies appeared to have prognostic value, since progression rate survival was significantly (log-rank test) associated with their expression of EGFR (P = 0.017), T138 (P = 0.0009) and T43 (P = 0.031). T138 expression was found to have an independent significant prognostic value using a stepwise logistic regression. T138 antibody may add significant information to classical pathological parameters.

Antibodies, Monoclonal↗