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Dive into the research topics where Michel Bazinet is active.

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Featured researches published by Michel Bazinet.


Urology | 1997

Outcome of sextant biopsy according to gland volume

Pierre I. Karakiewicz; Michel Bazinet; Armen Aprikian; Claude Trudel; Samuel Aronson; Mahmoud Nachabe; François Péloquint; Jean Dessureault; Michelle S. Goyal; Louis R. Bégin; Mostafa M. Elhilali

OBJECTIVES To reassess positive rate of sextant biopsy according to gland size. METHODS We evaluated 1974 consecutive men with systematic sextant biopsy, among whom we examined biopsy yield according to gland-volume intervals of 10 cc. RESULTS Decreasing yield of sextant biopsy is strongly associated with increasing gland volume (P < 0.001). Highest biopsy rate (39.6%) was recorded among men with prostates smaller than 20 cc. The lowest biopsy rate (10.1%) was recorded among men with prostates between 80 and 89.9 cc. Among men with biopsy-proven cancer, age, serum prostate-specific antigen, and Gleason grade were comparable (P > 0.05) throughout the range of gland-volume intervals. CONCLUSIONS Our findings suggest that gland size represents an important determinant contributing to the yield of sextant biopsy in men at risk of harboring a nonpalpable, isoechoic cancer. Consequently, an individualized sector biopsy approach, based on prostate volume, may warrant consideration because it may ensure superior detection of clinically significant disease among all men at risk, regardless of prostate size.


Urology | 1994

Prospective evaluation of prostate-specificantigen density and systematic biopsies for early detection of prosttic carcinoma

Michel Bazinet; Alaa W. Meshref; Claude Trudel; Samuel Aronson; Francois Peloquin; Mahmoud Nachabe; Louis R. Bégin; Mostafa M. Elhilali

Significant controversies persist in regard to the need for systematic biopsies in patients with serum prostate-specific antigen (PSA) levels above 4 ng/mL (Hybritech assay), especially if they show no signs of prostatic cancer on digital rectal examination (DRE) or transrectal ultrasonography (TRUS). We evaluated 565 consecutive patients referred to us for prostatism, suspicious lesions on DRE, or an elevated serum PSA level. These patients do not represent a purely screened population. A detection rate of 38.4 percent was achieved by performing directed biopsies of suspicious lesions on DRE and/or TRUS, and systematic biopsies of all patients with serum PSA levels above 4 ng/mL. Among 142 patients with serum PSA between 4.1 and 10 ng/mL, but without suspicion for cancer on DRE and TRUS (DRE- TRUS-), a large number of patients (6.2) were subjected to systematic biopsies to detect one cancer. A receiver-operating characteristics curve for PSA density (PSAD) applied to this population confirmed that the best cut-off point for biopsies was a PSAD of 0.15, below which only two of twenty-three cancers would have been missed, sparing biopsies in 77 of 142 patients. A similar approach was applied to DRE- TRUS- patients with serum PSA levels above 10 ng/mL. The number of cancers in those with serum PSA between 10.1 and 14 ng/mL was too low to establish a PSAD cut-off point. In patients with serum PSA above 14 ng/mL, the best PSAD cut-off point for biopsies was 0.3, below which two of thirteen cancers would have been missed, sparing biopsies in 19 of 39 patients. We conclude that PSAD can safely reduce the number of patients subjected to systematic biopsies without significantly compromising cancer detection.


The Journal of Urology | 1996

Value of Systematic Transition Zone Biopsies in the Early Detection of Prostate Cancer

Michel Bazinet; Pierre I. Karakiewicz; Armen Aprikian; Claude Trudel; Samuel Aronson; Mahmoud Nachabe; Francois Peloquin; Jean Dessureault; Michelle S. Goyal; Wei Zheng; Louis R. Bégin; Mostafa M. Elhilali

PURPOSE A prospective study was done to determine the value of performing 2 systematic transition zone biopsies in addition to systematic sextant peripheral zone biopsies for early detection of prostate cancer. MATERIALS AND METHODS From January 1 to August 31, 1994 we evaluated 847 consecutive patients referred to us for a suspicious lesion on digital rectal examination or an elevated serum prostate specific antigen level. All patients underwent 2 systematic transition zone biopsies in addition to systematic sextant biopsies of the peripheral zone. RESULTS Of the transition zone biopsies 68 (24.4%) contained malignancy, including only 8 (2.9%) with cancer found exclusively in the transition zone. The remaining 271 cases (97.1%) had 1 or more positive peripheral zone biopsies and would have been detected with or without additional systematic transition zone biopsies. The same analysis of 552 patients with a negative digital rectal examination yielded 6 (4.1%) exclusively transition zone tumors among 145 cancers detected in this group. CONCLUSIONS The low additional yield of transition zone biopsies (2.9 to 4.1%) does not warrant their systematic use for the early detection of prostate cancer.


The Journal of Urology | 1995

Family history and the risk of prostatic carcinoma in a high risk group of urological patients.

Armen Aprikian; Michel Bazinet; Mark Plante; Alaa W. Meshref; Claude Trudel; Samuel Aronson; Mahmoud Nachabe; Francois Peloquin; Jean Dessureault; Steven A. Narod; Louis R. Bégin; Mostafa M. Elhilali

PURPOSE We examine the association of family history and prostatic carcinoma. MATERIALS AND METHODS A total of 2,968 consecutive patients referred for prostate cancer detection responded to a questionnaire and underwent transrectal ultrasound examination with or without biopsy. RESULTS Of the men 329 (11.1%) had a family history of prostate cancer. No differences were observed between groups with and without a family history with respect to mean patient age, serum prostate specific antigen level or biopsy rate. Prostate cancer was detected in 133 of 329 patients (40.4%) with a family history and 769 of 2,639 (29.1) with no family history (p < 0.001, odds ratio 1.7). No significant differences were observed between cancer patients with or without a family history with respect to mean Gleason score (6.0 versus 6.2), patient age at diagnosis (65.8 versus 66.7) and prostate specific antigen level (16.8 versus 17.1). CONCLUSIONS Patients with a family history of prostate cancer have a greater risk of the disease. In this select group of patients a positive family history was not associated with an earlier age at cancer diagnosis or a different histological grade of tumor.


Urology | 1997

Morphologic changes induced by neoadjuvant androgen ablation may result in underdetection of positive surgical margins and capsular involvement by prostatic adenocarcinoma

Michel Bazinet; Wei Zheng; Louis R. Bégin; Armen Aprikian; Pierre I. Karakiewicz; Mostafa M. Elhilali

OBJECTIVE Neoadjuvant androgen ablation (NAAA) causes significant cytoarchitectural changes in both benign and malignant prostatic epithelial cells that may contribute to underdetection of prostate cancer capsular involvement and positive surgical margins. METHODS The aim of this study is to determine the ability of cytokeratin immunohistochemistry to enhance the determination of pathologic stage of prostate cancer following NAAA. RESULTS Cytokeratin AE1/AE3 immunohistochemistry identified 6 (27.3%), 15 (68.2%), 5 (22.7%), and 5 (22.7%) cases of organ-confined disease, capsule penetration, positive surgical margin, and seminal vesicle involvement, respectively, as compared with 10 (45.5%), 10 (45.5%), 3 (13.6%), and 5 (22.7%) cases by hematoxylin-eosin (H&E) staining, respectively. Two cases without detectable tumor by H&E staining had demonstrable residual tumor by cytokeratin immunohistochemical staining. CONCLUSIONS Cytokeratin immunohistochemistry revealed more extensive intracapsular, capsular, and extracapsular tumor involvement and higher rate of positive surgical margin than did conventional H&E staining. Therefore, the beneficial pathologic effects of NAAA observed may, in part, be attributable to the artifact of observation.


Urology | 1998

Thirty-day mortality rates and cumulative survival after radical retropubic prostatectomy

Pierre I. Karakiewicz; Michel Bazinet; Armen Aprikian; Simon Tanguay; Mostafa M. Elhilali

OBJECTIVES To assess the 30-day mortality rate and overall survival after radical retropubic prostatectomy (RRP). METHODS Identification of all RRPs performed in the Province of Quebec between January 5, 1988 and January 16, 1996 was accomplished through the Quebec Healthcare Plan Database. RESULTS Four thousand nine hundred ninety-seven RRPs were performed by 104 urologists. Overall, 451 deaths were recorded: 32 occurred during the first 30 days (0.6% 30-day mortality rate). A significant decrease in the 30-day mortality rate, from 2.45% to 0.5%, was recorded during the span of the study. The year of surgery, patient age, and hospital type were statistically significant short-term mortality variables (life table analysis). Patient age and year of surgery determined the cumulative survival probability (univariate and multivariate Cox analysis). Cumulative survival at 31 months of follow-up increased from 88.2% in 1988 to 98.1% in 1995. Men 75 years old and older were at a clear disadvantage with regard to survival probability compared with their younger counterparts. CONCLUSIONS In this population-based analysis of RRP outcomes, we demonstrated a significant improvement in short- and long-term outcomes, as evidenced by a decrease in the 30-day mortality rate and an improved cumulative survival, recorded over the span of the study. The recorded outcome trends may be explained by improved patient selection and optimal management. Although we are unable to determine cancer-specific outcomes, the results of this analysis should prove valuable to urologists and patients until there are results from randomized trials.


Urology | 2003

Cross-cultural validation of the UCLA prostate cancer index☆

Pierre I. Karakiewicz; Michael W. Kattan; Simon Tanguay; Mostafa M. Elhilali; Michel Bazinet; Peter T. Scardino; Armen Aprikian

OBJECTIVES To explore the impact of cross-cultural differences on University of California, Los Angeles, Prostate Cancer Index (PCI) reliability and validity, which is unknown. The PCI represents the most widely used prostate cancer-specific health-related quality-of-life assessment tool. METHODS The PCI sexual and urinary scales, the RAND SF-36 survey, and the Prostate Outcomes Research Team (PORT) prostate cancer treatment complication profile were self-administered. The principal sample consisted of 2415 men (anglophone 256, francophone 2159) treated with radical prostatectomy in Quebec between 1988 and 1996. An additional 35 men (anglophone 17, francophone 18) formed the retest sample. RESULTS The PCI demonstrated excellent internal consistency and test-retest reliability in tests based on the entire cohort and in tests addressing the two linguistically different groups. The instrument showed a lack of convergence with the SF-36 scales, confirming the distinctness of the generic and prostate cancer-specific constructs. The PCI sexual scales converged with the aggregate PORT sexual items (r = 0.8), and the PCI urinary scales were strongly related to the aggregate PORT urinary items (r = 0.7). Convergence between PCI urinary bother and function was strong (r = 0.8), but only moderate convergence was noted between PCI sexual bother and function (r = 0.4). The relation between bother and function in both urinary and sexual domains was weaker in anglophone participants relative to their francophone counterparts. CONCLUSIONS The PCI is reliable and, at best, only modestly affected by cultural differences when administered to culturally distinct English-speaking men or when translated into French.


Urology | 1998

Three-dimensional computer-assisted analysis of sector biopsy of the prostate☆

Pierre I. Karakiewicz; James A. Hanley; Michel Bazinet

OBJECTIVES To assess the relationship between tumor volume, gland volume, number of sectors submitted to biopsy, and prostatic biopsy detection rate. METHODS Using a three-dimensional mathematical model of the prostate, we assessed detection rates achieved with 4-, 6-, 8-, 10-, and 12-sector biopsies for glands ranging from 20 to 100 cc and peripheral zone tumors ranging from 0.3 to 1.4 cc. RESULTS Quadrant and sextant biopsy approaches only yielded from 6.2% to 13.4% and 8.6% to 18.3%, respectively, of lesions in a 40-cc gland. Conversely, 10- and 12-sector approaches yielded, respectively, from 19.8% to 48.8% and 25.4% to 62% of lesions for the same gland size. When assessed according to the density of sampling, one biopsy core used for every 1 .5 to 3.5 cc of prostatic tissue detected 42.5% of 0.5-cc lesions. For the same lesion size, the density of sampling per biopsy core was then decreased to intervals extending from 3.6 to 7.5 cc, 7.6 to 12.5 cc, and 12.6 to 25 cc. These sampling density intervals yielded, respectively, 25.0%, 15.8%, and 9.8% detection rates. CONCLUSIONS On the basis of our results, a gland volume-based biopsy algorithm is likely to result in improved detection of clinically significant prostate cancer.


Urology | 1996

Computer-assisted comparative analysis of four-sector and six-sector biopsies of the prostate

Pierre I. Karakiewicz; Armen Aprikian; Alaa W. Meshref; Michel Bazinet

OBJECTIVES To assess the potential difference in positive biopsy rates between four-sector and six-sector biopsy methods. METHODS This computer-assisted analysis is based on the records of 156 consecutive patients previously diagnosed with T1c cancer on systematic sextant biopsy of the peripheral zone. For each patient the computer randomly deleted one biopsy result from the left and right prostatic lobes. The deletion process was repeated 1000 times. Based on four randomly chosen biopsy cores, we determined the number of undetected cancers initially diagnosed with sextant biopsy. RESULTS Based on four-sector biopsy cores of the peripheral zone, between 6 and 30 (3.8% to 19.2% of cases) nonpalpable, isoechoic prostate cancers that were detected with sextant biopsy would have remained undiagnosed. CONCLUSIONS Our results suggest that the number of biopsy cores used in the early detection of nonpalpable, isoechoic prostate cancer may substantially affect the rate of positive findings.


Urology | 1997

Patient attitudes regarding treatment-related erectile dysfunction at time of early detection of prostate cancer

Pierre I. Karakiewicz; Armen Aprikian; Michel Bazinet; Mostafa M. Elhilali

OBJECTIVES To assess potency rate and patient attitudes regarding erectile dysfunction. METHODS A multiple choice, self-administered questionnaire distributed to 750 men undergoing testing for early detection of prostate cancer was used. RESULTS Overall, 33.9% of patients reported either partial or complete lack of erections and 31.1% were not sexually active or active less than once per month. Furthermore, 55.4% would be affected or very affected by lack of erections and 73.6% chose definitive treatment despite a 50% chance of erectile dysfunction. Finally, 47.4% found such treatment-induced erectile dysfunction to be an important or very important problem. When asked to ascribe a quantity of life or period of time that they would be willing to sacrifice to preserve sexual function following treatment, only 15.2% of patients were able to do so, but no consensus could be reached regarding its value. CONCLUSIONS Reported differences in quality-adjusted life expectancy when screening was compared to no screening and definitive therapy was compared to expectant management are marginal. Therefore, close attention to seemingly minor variables such as existing impotence rate, attitude regarding erectile dysfunction, and willingness to undergo therapy despite its inherent morbidity may substantially reduce or even reverse this reported disadvantage.

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Armen Aprikian

McGill University Health Centre

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