Biomedical subjects

Kazuto Ito

Publications and source records attributed to Kazuto Ito.

At least 19 recordsLinked to original sources

PubMed2007

Global update on defining and treating high-risk localized prostate cancer with leuprorelin: an Asian perspective.

Data from the Japanese Urological Society showed that, in Japan, almost half of patients with localized prostate cancer are treated with hormone therapy (HT), regardless of disease stage, and that radiation therapy (RT) is also widely used to treat high-risk patients. A retrospective study was undertaken in Japan to evaluate the potential benefits of using primary HT in locally advanced prostate cancer. Of 628 patients in the study, 63.5% were treated with combined androgen blockade (CAB; luteinizing hormone-releasing hormone agonists plus an antiandrogen) and 36.5% with medical or surgical castration. CAB treatment was significantly better than hormone monotherapy for disease-specific survival. The results also showed that, even if a patient is classified as 'high-risk', a good prognosis could normally be predicted based on certain variables: if their initial prostate-specific antigen (PSA) level was < or = 20 ng/mL, their Gleason score was < or = 6, and their nadir PSA decreased to < or = 0.2 ng/mL within 6 months of HT. In this subgroup of 'good responders', any treatment, be it prostatectomy, RT or CAB, is likely to be effective. However, in 'poor responders', combined therapies with CAB and high-dose rate brachytherapy are likely to be needed for a clinical response. While HT is effective, it might be associated with a reduction in the patient's quality of life (QoL) due to adverse effects, e.g. a reduction in sexual function. Results from the analysis of QoL questionnaires completed by men of different ages with prostate cancer found that only sexual function, and not other QoL variables, in men aged 50-59 years appeared to be reduced in men who had HT, compared to age-matched controls.

Antineoplastic Agents, Hormonal↗

PubMed2006

Clinical validity of proliferating cell nuclear antigen as an objective marker for evaluating biologic features in patients with untreated prostate cancer.

BACKGROUND: Although Gleason grading may be the most useful system for evaluating biological activity of untreated prostate cancer, lack of interobserver validity with Gleason scores (GS) is an unsolved issue. In this study, the proliferating cell nuclear antigen labeling index (PCNA LI) in untreated prostate cancer was investigated in order to clarify the usefulness of supplemental and objective markers for evaluating the biologic features of prostate cancer. METHODS: Sixty cases of prostate cancer were randomly selected from the cancer registry in Gunma University Hospital for this study. PCNA LI were evaluated using paraffin-embedded biopsy cores taken at diagnosis. Correlation of PCNA LI with the Gleason grading system, clinical stage, serum prostate-specific antigen (PSA) levels and age were evaluated. Cumulative rates of freedom from cause-specific death were also evaluated stratified by various clinicopathologic features, including PCNA LI using Kaplan-Meier analysis. RESULTS: Proliferating cell nuclear antigen labeling index was significantly higher in patients with PSA levels over 100 ng/mL, advanced clinical stage (>T4, N1 or M1 disease), higher Gleason grade or with a higher GS than in those with other clinicopathologic features. The 5-year cumulative rate of death from prostate cancer was significantly higher at 62% in patients with a PCNA LI of 20 or more than those with PCNA LI of less than 20, who accounted for 4%. CONCLUSIONS: Proliferating cell nuclear antigen labeling index in combination with Gleason grading system may be of clinical value in evaluating biologic features and also in predicting cause specific survival of prostate cancer in an objective, reliable and reproducible manner.

Aged↗

PubMed2005

Acute genitourinary toxicity after high-dose-rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity.

PURPOSE: Several investigations have revealed that the alpha/beta ratio for prostate cancer is atypically low, and that hypofractionation or high-dose-rate (HDR) brachytherapy regimens using appropriate radiation doses may be expected to yield tumor control and late sequelae rates that are better or at least as favorable as those achieved with conventional radiation therapy. In this setting, we attempted treating localized prostate cancer patients with HDR brachytherapy combined with hypofractionated external beam radiation therapy (EBRT). The purpose of this study was to evaluate the feasibility of using this approach, with special emphasis on the relationship between the severity of acute genitourinary (GU) toxicity and the urethral dose calculated from the dose-volume histogram (DVH) of HDR brachytherapy. METHODS AND MATERIALS: Between September 2000 and December 2003, 70 patients with localized prostate cancer were treated by iridium-192 HDR brachytherapy combined with hypofractionated EBRT at the Gunma University Hospital. Hypofractionated EBRT was administered in fraction doses of 3 Gy, three times per week; a total dose of 51 Gy was delivered to the prostate gland and the seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography (TRUS)-guided HDR brachytherapy. The fraction size and the number of fractions in HDR brachytherapy were prospectively changed, whereas the total radiation dose for EBRT was fixed at 51 Gy. The fractionation in HDR brachytherapy was as follows: 5 Gy x 5, 7 Gy x 3, 9 Gy x 2, administered twice per day, although the biologic effective dose (BED) for HDR brachytherapy combined with EBRT, assuming that the alpha/beta ratio is 3, was almost equal to 138 in each fractionation group. The planning target volume was defined as the prostate gland with 5-mm margin all around, and the planning was conducted based on computed tomography images. The number of patients in each fractionation group was as follows: 13 in the 5-Gy group; 19 in the 7-Gy group, and 38 in the 9-Gy group. The tumor stage was T1 in 10 patients, T2 in 36 patients, and T3 in 24 patients. The Gleason score was 2-6 in 11 patients, 7 in 34 patients, and 8-10 in 25 patients. Androgen ablation was performed in all the patients. The median follow-up duration was 14 months (range 3-42 months). The toxicities were graded based on the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity criteria. RESULTS: The main symptoms of acute GU toxicity were dysuria and increase in urinary frequency or nocturia. The grade distribution of acute GU toxicity in the patients was as follows: Grade 0-1, 39 patients (56%), and Grade 2-4, 31 patients (44%). One patient who developed acute urinary obstruction was classified as having Grade 4 toxicity. Comparison of the distribution of the grade of acute GU toxicity among the different fractionation groups revealed no statistically significant differences among the groups. The urethral dose in HDR brachytherapy was evaluated using the following DVH parameters: V30 (percentage of the urethral volume receiving 30% of the prescribed radiation dose), V80, V90, V100, V110, V120, V130, and V150. The V30-110 values in the patients with Grade 2-4 acute GU toxicity were significantly higher than those in patients with Grade 0-1 toxicity. On the other hand, there were no significant differences in the V120-150 values between patients with Grade 0-1 and Grade 2-4 toxicity. Regarding the influence of the number of needles implanted for the radiation therapy, patients with 11 needles or less showed a significantly higher incidence of Grade 2-4 acute GU toxicity compared with those with 12 needles or more (p < 0.05). CONCLUSIONS: It was concluded that HDR brachytherapy combined with hypofractionated EBRT is feasible for localized prostate cancer when considered from the viewpoint of acute toxicity. Increase in the fraction dose or reduction in the number of fractions in HDR brachytherapy did not affect the severity of acute GU toxicity, and the volume of urethra receiving an equal or lower radiation dose than the prescribed dose was more closely associated with the grade severity of acute GU toxicity than that receiving a higher than the prescribed dose.

Aged↗

PubMed2005

Acute genitourinary toxicity after high dose rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Second analysis to determine the correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity.

PURPOSE: We have been treating localized prostate cancer with high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiation therapy (EBRT) at our institution. We recently reported the existence of a correlation between the severity of acute genitourinary (GU) toxicity and the urethral radiation dose in HDR brachytherapy by using different fractionation schema. The purpose of this study was to evaluate the role of the urethral dose in the development of acute GU toxicity more closely than in previous studies. For this purpose, we conducted an analysis of patients who had undergone HDR brachytherapy with a fixed fractionation schema combined with hypofractionated EBRT. METHODS AND MATERIALS: Among the patients with localized prostate cancer who were treated by 192-iridium HDR brachytherapy combined with hypofractionated EBRT at Gunma University Hospital between August 2000 and November 2004, we analyzed 67 patients who were treated by HDR brachytherapy with the fractionation schema of 9 Gy x two times combined with hypofractionated EBRT. Hypofractionated EBRT was administered at a fraction dose of 3 Gy three times weekly, and a total dose of 51 Gy was delivered to the prostate gland and seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography-guided HDR brachytherapy. The planning target volume was defined as the prostate gland with a 5-mm margin all around, and the planning was conducted based on computed tomography images. The tumor stage was T1c in 13 patients, T2 in 31 patients, and T3 in 23 patients. The Gleason score was 2-6 in 12 patients, 7 in 34 patients, and 8-10 in 21 patients. Androgen ablation was performed in all the patients. The median follow-up duration was 11 months (range 3-24 months). The toxicities were graded based on the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer toxicity criteria. RESULTS: The main symptoms of acute GU toxicity were dysuria and increase in the urinary frequency or nocturia. The grade distribution of acute GU toxicity in the patients was as follows: Grade 0-1, 42 patients (63%); Grade 2-3, 25 patients (37%). The urethral dose in HDR brachytherapy was determined using the following dose-volume histogram (DVH) parameters: V30 (percentage of the urethral volume receiving 30% of the prescribed radiation dose), V80, V90, V100, V110, V120, V130, and V150. In addition, the D5 (dose covering 5% of the urethral volume), D10, D20, and D50 of the urethra were also estimated. The V30-V150 values in the patients with Grade 2-3 acute GU toxicity were significantly higher than those in patients with Grade 0-1 toxicity. The D10 and D20, but not D5 and D50, values were also significantly higher in the patients with Grade 2-3 acute GU toxicity than in those with Grade 0-1 toxicity. Regarding the influence of the number of needles implanted, there was no correlation between the number of needles implanted and the severity of acute GU toxicity or the V30-V150 values and D5-D50 values. CONCLUSIONS: It was concluded that HDR brachytherapy combined with hypofractionated EBRT is feasible for localized prostate cancer, when considered from the viewpoint of acute toxicity. However, because the urethral dose was closely associated with the grade of severity of the acute GU toxicity, the urethral dose in HDR brachytherapy must be kept low to reduce the severity of acute GU toxicity.

Aged↗

PubMed2005

Effectiveness of adjuvant intermittent endocrine therapy following neoadjuvant endocrine therapy and external beam radiation therapy in men with locally advanced prostate cancer.

PURPOSE: To clarify the optimal duration and methods for adjuvant endocrine therapy after external beam radiation therapy (EBRT) in patients with locally advanced prostate cancer. MATERIALS AND METHODS: Between 2001 and 2003, 215 patients with locally advanced prostate cancer were enrolled in the study. Patients were registered as primary candidates of the study and were treated with 6 months of LHRH agonist, with short-term of antiandrogen treatment for flare-up prevention. Patients with PSA levels below 10 ng/ml after the 6-month endocrine treatment were randomly divided into two arms. Then, a total dose of 72 Gy was given to the prostate. After 14 months of the protocol treatment, patients were treated with continuous androgen ablation (arm 1) or intermittent androgen ablation (arm 2). RESULTS: A total of 188 cases (87%) remained in the protocol. The median PSA level at entry was 25.3 ng/ml. The Gleason score was 2-6 in 32 cases (16%), 7 in 94 cases (48%), and 8-10 in 68 cases (35%). The median PSA level showed a remarkable decrease to 1.1, 0.2, and 0.1 ng/ml, after 6, 8, and 14 months of the protocol treatment, respectively. Of the 157 cases treated with EBRT, 153 cases (97.5%) had no biochemical failure in the mean follow-up of 17.3 months. CONCLUSIONS: The present study may reveal the possibilities of intermittent endocrine therapy after EBRT. However, the follow-up interval is short and little can be said about the results observed so far, exception of acute tolerance and patient acceptance of the protocol.

Adenocarcinoma↗

PubMed2005

Prostate carcinoma detection and increased prostate-specific antigen levels after 4 years in Dutch and Japanese males who had no evidence of disease at initial screening.

BACKGROUND: In the current study, the authors set out to investigate the possibility that increased prostate-specific antigen (PSA) levels in Dutch and Japanese men without suspicious findings at initial prostate cancer screening were indicative of the risk of newly developing clinical malignancy in the Netherlands and Japan. METHODS: Between 1992 and 2000, 2650 men ages 55-74 years who had PSA levels < 4.0 ng/mL and no suspicious findings on digital rectal examination were entered into the current study from a population-based prostate cancer screening cohort in Gunma Prefecture, Japan. In addition, between 1994 and 1997, 3163 men with the same clinical background were entered into the current study from the Rotterdam (Netherlands) Section of the European Randomized Study of Screening for Prostate Cancer (ERSPC). Prostate carcinoma incidence and the cumulative probability of freedom from PSA increases to levels > 2.0, 3.0, and 4.0 ng/mL, respectively, after 4 years of observation were compared between the Japanese and Dutch populations. The predictive value of initial PSA level, age at study entry, and geographic location also were investigated using Cox proportional hazards models. RESULTS: The overall risk of developing prostate carcinoma during the 4-year observation period was significantly higher for the ERSPC Rotterdam cohort (5.2%) compared with the Gunma cohort (1.6%). The cumulative probability of freedom from prostate carcinoma detection and freedom from an increase in PSA levels to >/= 4.0 ng/mL (PSA progression) decreased significantly with increasing initial PSA level and did not differ significantly between Japanese and Dutch patients whose initial PSA levels fell within the same range (0.0-0.9, 1.0-1.9, 2.0-2.9, or 3.0-3.9 ng/mL). Multivariate analysis also revealed that after controlling for age and initial PSA level, the probability of PSA progression was the same for Japanese and Dutch men. Initial PSA level was the only variable found to be significantly predictive of PSA progression on multivariate analysis (P < 0.0001). CONCLUSIONS: The risk of developing prostate carcinoma within a given 4-year period is greater for Dutch males ages 55-69 years compared with their Japanese counterparts, because the former have higher PSA levels. Nonetheless, there appears to be no significant difference in prostate carcinoma risk between Dutch and Japanese males whose baseline PSA levels fall within the same range.

Age Distribution↗

PubMed2005

[Cancer screening].

The purpose of cancer screening is to widen the difference between morbidity and mortality of the target cancer. Since 1983 cancer screening has been supported by the Japanese government. Initially it covered gastric and cervical cancer with lung, breast and endometrial cancers supported from 1987 and colorectal cancer in 1992. Since 1998 support for cancer screening has been transferred to local government. It is generally accepted that the uptake of screening services is too low. Estimates for Japan suggest that at best 30% of the eligible population accept the services. In other parts of the world screening is more widely accepted, for example, 67% for breast cancer and 79% for cervical screening in the USA. Barriers within Japan for increasing screening are complex and include, legal, ethical, financial, technical infrastructure, data related matters and the level of understanding and education of the general public. In 2000 the MHLW conducted an evaluation of cancer screening in terms of usefulness and effectiveness. It concluded that fair or better evidence for reduction in mortality existed for cervical cancer (cytology), breast cancer (mammography with clinical examination for women aged > or = 50 years), colorectal cancer (faecal occult blood test), gastric cancer, lung cancer and liver cancer. As a step towards improving screening services and their uptake by the general public a new Research Centre for Cancer Prevention and Screening was established at the National Cancer Centre in October 2003. This and other initiatives will build on the progress of the past 20 years but it is generally agreed that there is still have a long way to go.

Adult↗

PubMed2005

[Prostate biopsy].

Multiple core prostate biopsy was introduced by Eskew et al in 1995, and many procedures of multiple core biopsy were proposed. These methods showed importance of taking samples from lateral part of peripheral zone, transition zone or apex. Cancer detection rates were dramatically increased in comparison with those detected by traditional systematic sextant biopsy (SSB). Utilization of the template, age-volume adjusted parameter or apical horn biopsy facilitated the efficacy of multiple core biopsy. Furthermore, these techniques could contribute to accurate estimation of pathological findings. Multiple core prostate biopsy would get to be more important in modern prostate specific antigen era when more T1c or more early stage prostate cancer would be detected.

Aging↗

PubMed2004

Rectal bleeding after hypofractionated radiotherapy for prostate cancer: correlation between clinical and dosimetric parameters and the incidence of grade 2 or worse rectal bleeding.

PURPOSE: To investigate the incidence and severity of rectal bleeding after high-dose hypofractionated radiotherapy (RT) for prostate cancer, and to explore the factors affecting the incidence of Grade 2 or worse rectal bleeding. METHODS AND MATERIALS: The data of 52 patients who had been treated by external beam RT for localized prostate cancer between 1999 and 2002 were analyzed. All the patients had received hypofractionated external beam RT to a total dose of 69 Gy in 3-Gy fractions, three fractions weekly. The clinical and dosimetric factors affecting the incidence of Grade 2 or worse late rectal bleeding were analyzed by univariate and multivariate analyses. The effect of the percentage of the whole rectal volume receiving 30%, 50%, 80%, and 90% of the prescribed radiation dose (V(30), V(50), V(80), and V(90), respectively) on the incidence of rectal bleeding was evaluated. RESULTS: Of the 52 patients, 13 (25%) developed Grade 2 or worse rectal bleeding. One patient who needed laser coagulation and blood transfusion for the treatment of rectal bleeding was classified as having Grade 3 rectal bleeding. The median time to the development of Grade 2 or worse rectal bleeding was 11 months. The results of the univariate analysis revealed that the presence of a history of diabetes mellitus (p < 0.001), and V(30) >/= 60%, V(50) >/= 40% (p < 0.05), V(80) >/= 25%, and V(90) >/= 15% (p < 0.001) were statistically significant risk factors for the occurrence of Grade 2 or worse rectal bleeding. The results of the multivariate analysis revealed that a history of diabetes mellitus was the most statistically significant risk factor for the occurrence of rectal bleeding after hypofractionated RT for prostate cancer (p < 0.05). CONCLUSION: A history of diabetes mellitus was the most statistically significant risk factor for the occurrence of Grade 2 or worse rectal bleeding after high-dose hypofractionated RT, although dosimetric factors were also closely associated with the risk of rectal bleeding.

Aged↗

PubMed2004

External beam radiotherapy for clinically node-negative, localized hormone-refractory prostate cancer: impact of pretreatment PSA value on radiotherapeutic outcomes.

PURPOSE: To analyze the results of clinically node-negative, localized hormone-refractory prostate cancer treated with external beam radiotherapy (EBRT) and to investigate the potential prognostic factors that influenced the therapeutic outcome. METHODS AND MATERIALS: Fifty-three patients who had developed localized hormone-refractory prostate cancer were treated with EBRT between 1994 and 2001. According to the 1992 American Joint Committee on Cancer clinical stage, 4 patients had T2 and 49 had T3 at the start of RT, and 14 patients had a Gleason score <7, 14 had a Gleason score of 7, and 23 had a Gleason score of 8-10. All patients were treated with EBRT using the unblocked oblique four-field technique, with a total dose of 69 Gy. The fraction dose was 3 Gy three times weekly. The median follow-up after RT was 35 months (range, 8-96 months) and after androgen ablation was 73 months (range, 42-156 months). RESULTS: Of 53 patients, 15 patients subsequently developed clinical relapse, including locoregional and/or distant metastases. The site of first relapse was bone metastasis in 10, lymph nodes in 3, and local failure in 2 patients; 3 patients died of prostate cancer during the analysis period. The 3-year and 5-year cause-specific survival rate was 94% and 87%, respectively, and the 3-year and 5-year clinical relapse-free survival rate was 78% and 56%, respectively. The univariate analysis revealed that a short prostate-specific antigen (PSA) doubling time and high PSA value at the start of RT and a high Gleason score were statistically significant factors for the risk of clinical relapse. Multivariate analysis demonstrated that the PSA value (PSA or=15 ng/mL) at the start of RT was an independent prognostic factor. CONCLUSION: EBRT could be a treatment of choice for clinically node-negative, localized, hormone-refractory prostate cancer.

Aged↗

PubMed2004

Cumulative probability of PSA increase above 4.0 NG/ML in population-based screening for prostate cancer.

Routine screening for prostate cancer remains controversial. However, it is very important to show how the optimal rescreening interval should be set for men who want to be screened after informed consent. To solve this issue, the risk of prostate-specific antigen (PSA) increase above 4.0 ng/ml relative to baseline PSA levels and age was investigated. Between 1988 and 2000, 7,757 subjects screened twice or more and also with baseline PSA levels of 4.0 ng/ml or lower were enrolled in our study. All serum PSA levels were measured by E-test Tosoh II PA assay at one center. Interval PSA levels for men undergoing screening with a greater than 1 year interval were calculated on the assumption that PSA levels changed over time in a simple exponential fashion. Then, the cumulative rate of freedom from PSA increase above 4.0 ng/ml was estimated using the Kaplan-Meier technique stratified by baseline PSA ranges of 0.0 to 1.0, 1.1 to 2.0, 2.1 to 3.0 and 3.1 to 4.0 ng/ml and every 10 years of age ranges. Of the 7,757 subjects, 559 (7.2%) were expected to have had PSA levels increase above 4.0 ng/ml within 5 years after the baseline PSA measurements. The cumulative rate of freedom from the PSA increase above 4.0 ng/ml at 5 years was 98.7%, 92.9%, 70.3% and 38.5% in cases of baseline PSA levels of 1.0 ng/ml or lower, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml and 3.1 to 4.0 ng/ml, respectively. The cumulative rates of freedom from the PSA increase were significantly decreased with the baseline PSA ranges being higher regardless of age range. Re-screening interval should be set stratified by baseline PSA levels, regardless of age and race. Rescreening interval should be set at 1, 1 to 2 and 3 to 5 years for men with baseline PSA ranges of 2.1 to 4.0 ng/ml, 1.1 to 2.0 ng/ml and 0.0 to 1.0 ng/ml, respectively, in individual-based screening. In mass screening system using PSA alone, rescreening interval should be set in the same manner as in individual-based screening, except for men with baseline PSA levels of 1.1 to 2.0 ng/ml, which should be set at 1 year to avoid developing incurable prostate cancer.

Aged↗

PubMed2004

Diagnostic significance of PSA density adjusted by transition zone volume in males with PSA levels between 2 and 4ng/ml.

OBJECTIVE: To investigate the diagnostic significance of prostate-specific antigen (PSA), density (PSAD), and PSAD adjusted by transition zone volume (PSATZD) in men with PSA levels between 2.1 and 4.0ng/ml. METHODS: Between 1993 and 2000, 69 men with PSA levels between 2.1 and 4.0ng/ml underwent transrectal ultrasonography (TRUS) and 8-core prostate biopsy. Diagnostic accuracies for various cut-offs of PSAD and PSATZD were investigated according to subdivided PSA levels of 2.1 to 3.0ng/ml and 3.1 to 4.0ng/ml. RESULTS: The detection rate of prostate cancer was 21.7% (15/69). The percentage of patients with extracapsular disease was 33.3% (5/15) and primary Gleason grade 4 or 5 was obtained in 4 (26.7%) patients. The transition zone volume and PSATZD in cancer cases were significantly different in comparison with those in non-cancer cases. The area under the receiver operating characteristic curve for PSATZD was significantly higher in comparison with that for PSAD in the same subdivided PSA ranges. The diagnostic efficiency for PSATZD was higher than that for PSAD. The diagnostic efficiency showed the highest value at the cut-off level for PSATZD of 0.23 and 0.28 in men with PSA levels of 2.1 to 3.0ng/ml and 3.1 to 4.0ng/ml, respectively. CONCLUSIONS: The use of PSATZD cut-offs as a biopsy indication may reduce many unnecessary biopsies without missing most prostate cancer cases in the PSA range of 2.1 to 4.0ng/ml.

Adult↗

PubMed2004

Comparative study on the prevalence of clinically detectable prostate cancer in patients with and without bladder cancer.

OBJECTIVES: To investigate the prevalence of prostate cancer in patients with a past or present history of bladder cancer compared with age-matched control subjects in population-based screening for prostate cancer. METHODS: Between 1998 and 2000, 106 patients who were followed up in the outpatient clinic for bladder cancer (case cohort) and 1060 age-matched men who participated in screening for prostate cancer (control cohort) were enrolled in this study. Serum prostate-specific antigen (PSA) levels were measured for all participants, and all participants underwent digital rectal examination (DRE). The PSA distribution and prevalence rate of prostate cancer were compared between these two cohorts. RESULTS: The serum PSA levels were significantly greater in the case cohort than in the control cohort. The detection rate of prostate cancer was 12.3% (13 of 106) and 1.5% (16 of 1060) in the case and control cohorts, respectively. The biopsy compliance for those with abnormal PSA and/or DRE findings was significantly lower (31%) in the control cohort than in the case cohort (84%). If all those in the control cohort with abnormal PSA and/or DRE findings had undergone prostate biopsies, another 26 cases of prostate cancer might have been detected. The expected detection rate of prostate cancer in the control cohort was high at 4.0% (42 of 1060); however, this was still significantly lower than that in the case cohort. CONCLUSIONS: Patients with a present or past history of bladder cancer could be a high-risk group for developing or having prostate cancer. Additional studies should be conducted to confirm this.

Adenocarcinoma↗

PubMed2004

Prostate-specific antigen change in the European Randomized Study of Screening for Prostate Cancer, section Rotterdam.

OBJECTIVES: To determine the prostate-specific antigen (PSA) velocity, PSA slope, and PSA doubling time (PSADT) in men with positive biopsies, negative biopsies, and no biopsy indications 4 years after an initial screening; and to use this information to improve the test characteristics in the early detection of prostate cancer and provide normal values for these parameters in screened men with and without evidence of prostate cancer. METHODS: Within the European Randomized Study of Screening for Prostate Cancer, section Rotterdam, we identified 9575 men with a second determination of PSA 4 years after the initial screening. These men were divided into three groups: men with positive biopsies, negative biopsies, and no biopsy indications in the second round (PSA less than 3.0 ng/mL). The predictive values of PSA dynamics for detection of prostate cancer were calculated. RESULTS: The mean PSA velocity of men with prostate cancer was 0.62 ng/mL/yr versus 0.46 ng/mL/yr for men with a negative biopsy (P = 0.001). The mean PSADT for men with prostate cancer was 5.1 years and for those with a negative biopsy it was 6.1 years (P = 0.002). The PSADT for men with no indication for biopsy was 25.1 years. However, receiver operating characteristic analyses revealed only a moderate value for these test parameters in predicting biopsy outcome. CONCLUSIONS: The mean values of PSA velocity, PSA slope, and PSADT in a rescreened population differed significantly between men with and without prostate cancer. However, in predicting the biopsy outcome, the PSA dynamics were of limited value.

Adenocarcinoma↗

PubMed2004

Androgen-dependent blood flow control and morphological changes of the capillaries in rat prostate.

To clarify the effect of androgens on the microcirculation of the prostate, organ blood flow and ultrastructural features of the capillaries were investigated. In the ventral prostate (VP) of adult Wistar rats, organ blood flow was measured using a laser Doppler flowmetry, and the morphological features of the subepithelial capillaries were investigated and their luminal area was measured using transmission electron microscopy and a computed image analyzer at 1, 2, 3, and 7 days after castration, and 2 days after castration and gradational testosterone supplementation. The capillaries of the VP were classified into three types; oval opened (type 1), intermediate (type 2) and collapsed (type 3). Organ blood flow reduced from 40.5 to 27.7 mL/min/100 g (p < 0.0001) and the luminal area of the capillaries reduced from 13.5 to 4.5 microm2 (p < 0.0001) 2 days after castration. These reductions of the blood flow and the luminal area were gradationally prevented by testosterone supplementation. In the morphological features of the capillary, type 1 had rapidly shifted to types 2 and 3 after castration, and the shift of the capillary type was significantly prevented by the testosterone supplementation. These results clearly demonstrated that the androgen-dependent ultrastructural and morphological features in subepithelial capillaries revealed local microcirculatory conditions correlating the organ blood flow changes in VP.

Animals↗

PubMed2004

The risk of rapid prostate specific antigen increase in men with baseline prostate specific antigen 2.0 ng/ml or less.

PURPOSE: We estimated the risk of a rapid prostate specific antigen (PSA) increase in men with a low baseline PSA range of 0.0 to 2.0 ng/ml to investigate the validity of setting a re-screening interval of more than 1 year. MATERIALS AND METHODS: Between 1988 and 1999, 6,252 men with baseline PSA 2.0 ng/ml or less without suspicious findings on digital rectal examination (DRE) and 7,304 with the same baseline PSA who did not undergo DRE at the time of baseline PSA measurement were re-screened. The risks of a PSA increase to 4.1 to 10.0, 10.1 to 20.0 and greater than 20.0 ng/ml were investigated and stratified by re-screening interval, baseline DRE status, and subdivided baseline PSA ranges of 0.0 to 1.0 and 1.1 to 2.0 ng/ml. RESULTS: A total of 28 cases (0.2% of 13,556) of prostate cancer were detected after an average re-screening interval of 3.6 years. High PSA above 10 ng/ml at diagnosis was noted in 5 patients (18%), including 2 with a great PSA increase to 1,928 and 298 ng/ml at re-screening intervals of 4 and 6 years, respectively. CONCLUSIONS: Setting 4 to 5-year re-screening intervals for PSA measurements in men with PSA 1.0 ng/ml or less can decrease the cost of PSA tests without lowering sensitivity. A re-screening interval for PSA measurement should be set annually for men with PSA 1.1 to 2.0 ng/ml to minimize the risk of missing aggressive cancer.

Aged↗

PubMed2004

Role of androgen on blood flow and capillary structure in rat seminal vesicles.

To clarify the effect of androgen on the microcirculation in seminal vesicles of adult Wistar rats, we investigated the organ blood flow and morphological features in the capillaries after castration and subsequent testosterone supplementation. Testosterone (T) was subcutaneously injected every 12 hours after castration and its doses were set to 10(-2), 10(-1), 10(0) and 10(1) mg/kg-body weight (T10(-2), T10(-1), T10(0) and T10(1) groups, respectively). Organ blood flow was measured using laser Doppler flowmetry, and the subepithelial capillaries were analyzed using transmission electron microscopy. The capillaries were morphologically classified into 3 types; oval opened (type 1), intermediate (type 2) and collapsed (type 3), and their luminal areas were measured using a computed image analyzer. The organ blood flow was significantly reduced from 36.3+/-5.1 to 21.9+/-2.7 ml x min(-1)/100 g tissue, and the luminal area of the capillaries was significantly reduced from 9.02+/-1.28 to 4.85+/-0.82 microm2 with the shift of the type 1 and type 2 to type 3 after castration. The reduction of the luminal area and the blood flow reduction, and shift of the capillary type were significantly protected by gradated testosterone supplementation. These results indicate that the maintenance of the blood flow and morphological profiles in capillaries depend on androgen-supplementation levels in seminal vesicles.

Animals↗

PubMed2004

Incidence of bladder cancer discovered by urethrocystoscopy at prostate biopsy: extraordinary high incidence of tiny bladder cancer in elderly males.

In order to clarify the incidence of bladder cancer with and without prostate cancer, we investigated bladder cancer discovered incidentally by urethrocystoscopy at prostate biopsy. Between April 1997 and December 2003, 498 patients who were suspected prostate cancer were performed prostate biopsy and urethrocystoscopy simultaneously. We investigate possible invasion of prostate cancer into the urethra or bladder mucosa as well as bladder cancer, including other benign lesions of the bladder by urethrocystoscopy. Prostate cancer was confirmed in 175 (35.1%) of the 498 patients histologically, and bladder cancer was discovered incidentally in 12 patients (2.4 %). The incidence of bladder cancer in patients with prostate cancer of 2.3% (4/175) was not significantly different from that in patients without prostate cancer, which was 2.5% (8/323). Superficial and those with a size less than 1 cm were noted in 11 patients (92%) and 10 patients (83%) respectively. High incidence rate of bladder cancer with prostate cancer was reported previously, however, there was no study to compare the incidence rate of bladder cancer between cases with and without prostate cancer. The present study suggests that asymptomatic tiny bladder cancer may be present at an unexpectedly high incidence rate in elderly males.

Adult↗