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S Kuwao

Publications and source records attributed to S Kuwao.

At least 19 recordsLinked to original sources
PubMed1999

Limited suppression of prostate-specific antigen after salvage radiotherapy for its isolated elevation after radical prostatectomy.

OBJECTIVES: To investigate the clinical outcome and degree of prostate-specific antigen (PSA) suppression after salvage radiotherapy performed because of isolated PSA elevation after radical prostatectomy. METHODS: We examined the outcomes of 32 patients who underwent radiotherapy after radical prostatectomy. Hypersensitive, as well as conventional, PSA assays were used to measure PSA levels after irradiation. RESULTS: Of 125 patients who underwent radical prostatectomy for clinically resectable prostate cancer, 42 (33.6%) developed detectable PSA an average of 13.5 months postoperatively. Thirty-two patients underwent salvage radiotherapy. In 13 patients (40.6%), PSA became undetectable (less than 0.1 ng/mL) at a mean of 1.2 months. Two of these patients later developed detectable PSA within 1 2 months. Of 22 patients who had at least 12 months of follow-up, 8 had a durable PSA response. Of 13 patients who attained an undetectable PSA postoperatively and then showed a delayed progressive increase, 7 exhibited a durable response lasting for more than the 12 months after irradiation. By contrast, only 1 of 9 patients with persistently elevated postoperative PSA showed undetectable levels after irradiation. Frozen sera from the 8 patients with a durable response to irradiation were available to measure levels less than 0.1 ng/mL by hypersensitive assay. The mean value was 0.035 ng/mL at an average of 26.9 months after irradiation. Only 3 patients had levels less than 0.01 ng/mL. CONCLUSIONS: Although radiotherapy may be beneficial in a small number of patients, many patients continue to have measurable levels of PSA (more than 0.01 ng/mL) after irradiation. Our results suggest that this treatment in its current form is inadequate to eradicate residual carcinoma.

Aged↗
PubMed1999

[Indication of repeat prostatic biopsy following previous negative findings].

BACKGROUND: Many men with clinically suspicious findings would not be diagnosed to have prostate cancer. Establishing criteria for indicating repeat biopsy is imperative for early detection of prostate cancer. METHODS: Eighty-one patients underwent repeat prostatic biopsies under sonographic guidance at Kitasato University Hospital between March 1992 and October 1996. Clinicopathological parameters such as age, prostate specific antigen (PSA), PSA adjusted for transition zone volume (PSAT), PSA density (PSAD), PSA velocity, transition zone volume, prostatic volume, rectal findings, ultrasound findings and initial biopsy histology were compared with the results of repeat biopsy for searching for possible predictors of positive biopsy. RESULTS: Cancer was confirmed in 14 patients (17.3%), 10 patients by the second biopsy (15.4%, 10/65) and 4 patients by the third biopsy (28.6%, 4/14). No cancer was found at the 4th or more biopsies. Twelve (85.7%) of these patients had prostatic volume less than 40 cm3. Univariate analysis indicated PSAT, PSAD, transition zone volume and prostatic volume to be more frequent in men with positive biopsies (p < 0.05). But multivariate logistic regression analysis failed to identify any significant predictors of positive results in repeat biopsies. CONCLUSIONS: No clinicopathological parameters could reliably predict repeat biopsy findings. One or 2 additional sets of biopsies is recommended based on clinical judgement (symptoms, life expectancy, small glands < or = 40 cm3 etc.) for the purpose of early detection of prostate cancer in patients with previously negative biopsy but still with suspicious findings in consideration of approximately 20% false negative rates by the initial biopsy.

Aged↗
PubMed1999

[Histological characteristics and clinical significance of Japanese prostate cancer with low levels of prostate specific antigen of 4.0 ng/ml or lower].

PURPOSE: They set a normal limit of prostate specific antigen (PSA) to 4.0 ng/ml in Tandem R assay at most institutions. We investigated clinical and histological characteristics of prostate cancer based on whole mount step-section histology of radical prostatectomy specimens, and taking notice of Japanese prostate cancer whose levels of PSA are less than 4.0 ng/ml in normal levels. MATERIALS AND METHODS: One hundred and twenty-two patients underwent radical prostatectomy for clinically resectable prostate cancer at University Hospital from February 1992 to April 1997. Clinicopathological findings were stratified according to the preoperative PSA levels in 111 patients without preoperative endocrine therapy. Immunohistochemical study for PSA was conducted in 7 randomly selected patients. RESULTS: Of the patients 22 (19.8%) had normal (4.0 ng/ml or lower) preoperative serum PSA. Mean tumor volume in this PSA range was 1.5 cm3 with one pT 0 case included. Pathologically organ confined, potentially curable disease (< pT 3) was found in 17 (77.3%) patients and extracapsular extension and seminal vesicle invasion in 5 (23.8%), respectively. No patients had positive pelvic lymph nodes. Well differentiated tumors of Gleason scores 2-4 were found in 9 (40.9%) of the patients, moderately differentiated tumors (Gleason scores 5, 6) in 5 (22.7%) and poorly differentiated histology (Gleason scores 7-10) in 7 (31.8%). Sixteen (72.7%) patients had clinically significant tumors (> 0.5 cm3, Gleason score > or = 7). All 7 patients had positive staining for PSA, but its intensity did not correlate with serum PSA levels. CONCLUSIONS: Many prostate cancers found in surgical specimens were clinically significant despite the low levels of PSA and potentially curable by definitive treatment. Age, co-morbidity and other clinicopathological variables as well as PSA levels should all be taken into account when treatment options are discussed.

Aged↗
PubMed1998

Inadequacy of free prostate-specific antigen parameters in the prediction of pathologic extent of prostate cancer in Japanese men.

OBJECTIVES: To evaluate free prostate-specific antigen (PSA) and free to total PSA ratio as predictors of pathologic extent in Japanese patients with prostate cancer. METHODS: By TOSOH assay, pretreatment serum serologic markers of free PSA, total PSA, free to total PSA ratio, and PSA density (PSAD) were determined for 108 patients subsequent to radical prostatectomy for resectable prostate cancer. Serum values for these markers were compared with pathologic findings and tumor volume on the basis of pathologic assessment of whole mount section histology. RESULTS: Mean total PSA, free PSA, free to total PSA ratio, and PSAD significantly differed for pathologically confined (pT2 or lower) and advanced (pT3 or higher) cancers (P < 0.05). Total PSA, free PSA, and PSAD provided indication of seminal vesicle involvement, surgical margin status, nodal involvement, and total tumor volume (P < 0.05). Free PSA was more closely correlated with total tumor volume than the free to total PSA ratio; this ratio was not correlated with total tumor volume or specimen Gleason score. Free PSA and free to total PSA ratio were not found to be any more useful than total PSA and PSAD for predicting pT3 disease by receiver operating characteristic curve analysis. Multivariate logistic regression analysis and log likelihood ratio test results indicated little additional value of these parameters for predicting pT3 disease. CONCLUSIONS: Contrary to previous reports, free PSA and the free to total PSA ratio are of little use subsequent to the diagnosis of prostate cancer.

Adult↗
PubMed1998

Improved predictability of extracapsular extension and seminal vesicle involvement based on clinical and biopsy findings in prostate cancer in Japanese men.

OBJECTIVES: The accurate preoperative prediction of the extent of cancer by pathologic examination is essential for choosing the optimal treatment for patients with prostate cancer. Currently available clinical staging methods are not adequate and more precise staging is required. METHODS: Using the log likelihood ratio test and receiver operating characteristic (ROC) curve analysis, preoperative variables, including biopsy pathologic findings, were assessed for predicting final pathologic stage in prostate cancer. A multivariate model for predicting disease organ confinement status was established for easy clinical use. RESULTS: The use of the number of cores with cancer and maximum cancer length in conjunction with the three variables (prostate-specific antigen, clinical stage, and biopsy Gleason score) was found to significantly improve predictability of extracapsular extension and seminal vesicle involvement in clinically resectable (n = 96) and localized prostate cancers (n = 81) (P < 0.05). Areas under ROC curves for the above two parameter sets (five- versus three-variable model) were 0.8395 and 0.7109, respectively, for capacity for extracapsular extension prediction in clinically localized cancer. These values for seminal vesicle involvement were 0.7861 and 0.6927, respectively. The logistic model gave positive and negative predictive values of 73% and 78%, and 64% and 83%, respectively, for extracapsular extension and seminal vesicle involvement in clinically localized cancer at a predicted probability of 0.5 or greater. CONCLUSIONS: The present method may be used to predict non-organ-confined prostate cancer with greater accuracy than the previously reported model using three variables.

Aged↗
PubMed1998

Zonal biopsy in the detection of prostate cancer in Japanese men.

To reduce sampling error as much as possible in the detection of prostate cancer, extensive transition zone sampling, in addition to the standard sextant random systematic biopsies, has been proposed. Improved biopsy techniques should make possible earlier and more effective detection of prostate cancer in a population where the incidence is low. Evaluation of such biopsies for elderly Japanese males is thus required. A total of 344 Japanese patients participated in this study. They underwent two transition zone biopsies in addition to systematic biopsy. Fifty-five of the 344 patients (16.0%) had cancer. Both biopsies were positive in 33 patients (60.0%), the standard systematic sextant biopsy alone demonstrated cancer in further 20 (36.4%) and the transition zone biopsy alone was positive in two others (3.6%). The two patients with cancer only in the transition zone biopsy cores had palpable abnormality and elevated prostate specific antigen. None of those with palpably benign glands or those with prior negative biopsies had cancer in the transition zone. Two additional cores from the transition zone led to no increase in morbidity of biopsy. Transition zone biopsy would not significantly contribute to the detection of prostate cancer in the present Japanese elderly male population. Though possibly of some value for certain patients, this biopsy does not warrant routine use.

Adult↗
PubMed1998

Results of transrectal ultrasound-guided biopsies and clinical significance of Japanese prostate cancer.

BACKGROUND: We review the outcomes of ultrasound-guided biopsy in consecutive patients and assess clinical significance of Japanese prostate cancer. METHODS: Examination was made of 1469 patients subsequent to transrectal ultrasound-guided biopsy of the prostate gland. For 84 patients, two or more sets of ultrasound-guided biopsies were conducted following the initial negative results during this period. Two hundred and thirty-two patients with benign histology at the initial biopsy underwent transurethral resection of the prostate (TURP). The clinical significance of the cancers was assessed based on patient age and calculated tumor volume at diagnosis, assumed cancer volume doubling time and life-expectancy in the Japanese male population. RESULTS: Overall, 327 of the 1469 patients (22.3%) had prostate carcinoma. Positive biopsy rates in patients with PSA 2.0 ng/ml or lower, 2.1-4.0 ng/ml, 4.1-10.0 ng/ml and 10.1 ng/ml or greater were 4.6%, 8.6%, 15.8% and 59.5%, respectively. Of the 232 patients who underwent TURP, 15 (6.5%) had cancer. Of the 84 patients subjected to the multiple sets of biopsies, 19 (22.6%) cancers were detected. Of the 203 cancers without distant metastasis at initial biopsy, 13.3%, 25.1%, 32.5% and 40.4% of tumors for 2-, 3-, 4- and 6-year tumor doubling times gave no indication of clinical significance. Nearly half these patients (43-52%) had clinical stage T1c disease. The estimated proportion of clinically insignificant tumors in repeat biopsy was virtually the same as first set biopsies. CONCLUSIONS: Low PSA was not necessarily an indication of indolent cancer and repeat biopsy did not often demonstrate clinically unimportant cancers. Many patients with stage T1c disease may eventually prove to require no treatment.

Adult↗
PubMed1998

A primary solitary tumor of the lesser omentum with immunohistochemical features of gastrointestinal stromal tumors.

We here present a primary solitary tumor of the lesser omentum that was found in a 71-yr-old woman. Differential diagnosis could not be made preoperatively; therefore, histopathological examination including immunohistochemical studies were performed to determine the nature of the tumor. The resected specimen, measuring 17 cm at the largest point, consisted of the outer solid part and the inner multiloculated cysts. Microscopically, the tumor was characterized by interlacing bundles of elongated spindle cells, with the nuclei focally showing a palisading pattern. However, skeinoid fibers were not observed anywhere. One to three mitoses per 50 high power fields were observed. Immunohistochemically, the tumor was negative for S-100 protein and smooth muscle-specific actin, but stained positive for CD34. The microscopic features were consistent with those of potentially malignant gastrointestinal stromal tumors. Stromal tumors that represent the differentiation toward neither typical leiomyomas or schwannomas rarely occur in the lesser omentum with only one such instance having been reported to date. Due to this rarity, it is difficult to make the differential diagnosis preoperatively, even with existing imaging techniques, and predicting the clinical behavior of such omental tumors is also often difficult. Therefore, complete resection should be performed when such tumors are encountered in daily practice.

Actins↗
PubMed1998

An autopsy case of troglitazone-induced fulminant hepatitis.

OBJECTIVE: To study an autopsy case of troglitazone-induced fulminant hepatitis. CASE REPORT: A 58-year-old man contracted severe hepatitis 2 months after administration of troglitazone for the treatment of type 2 diabetes. Liver damage progressed gradually, even after withdrawal of the agent. Despite intensive therapy, the hepatitis became fulminant and the patient died 8 weeks after the onset of liver damage. Autopsy revealed massive hepatic necrosis and cholestasis with inflammatory cell infiltration. The pathological findings and the positive result of the drug-induced lymphocyte stimulation test for troglitazone indicated that the liver damage was mediated by hypersensitivity to troglitazone. CONCLUSIONS: One report has attributed troglitazone-induced liver damage in less severe cases to idiosyncratic reactions. However, the present case indicates that troglitazone can induce hypersensitivity resulting in fulminant hepatitis. Careful monitoring of serum liver enzymes during troglitazone therapy is therefore essential.

Alanine Transaminase↗
PubMed1997

The ratio of free to total serum prostate specific antigen and its use in differential diagnosis of prostate carcinoma in Japan.

BACKGROUND: To improve the clinical usefulness of prostate specific antigen (PSA), unique methods have been proposed. The percentage of free PSA in serum facilitates the distinction between benign histologic conditions and prostate carcinoma while retaining high sensitivity. METHODS: Using monoclonal antibodies, an AIA total PSA assay system was established that recognized PSA equally in free or complex form. The clinical usefulness of the ratio of two different molecular forms of PSA was investigated using 268 archival serum samples. RESULTS: Men with prostate carcinoma had significantly lower ratios of free to total PSA than those with benign prostatic hyperplasia (BPH) (P = 0.0001). At total PSA levels between 2.1 and 10 ng/mL, medians of total PSA were not significantly different between men with prostate carcinoma and men with BPH. Differences in median percentages of free PSA for these two groups were statistically significant (P = 0.0001). The ratio of free to total PSA was useful for identifying prostate carcinoma in palpably benign glands with total PSA of 2.1-10 ng/mL (P = 0.0001), whereas total PSA was not useful for such identification. When calculated for low total PSA levels between 2.1 and 4 ng/mL, sensitivity and specificity were 91.7% and 72.2%, respectively, with a cutoff value of 17%. This ratio of free to total PSA was as useful as PSA density in receiver-operating curve analysis. CONCLUSIONS: The use of the ratio of free to total PSA renders total PSA of greater use of distinguishing prostate carcinoma and is applicable to patients with low total PSA. Elderly men with a clinical diagnosis of BPH who are scheduled for surgery may benefit from the determination of this ratio.

Aged↗
PubMed1997

Impact of life expectancy and tumor doubling time on the clinical significance of prostate cancer in Japan.

Theoretical projected prostate cancer volume at the time of expected death was determined based on patient age and index cancer volume at diagnosis, assumed cancer volume doubling time and life expectancy of the Japanese male population. Based on the data obtained, evaluation was made of the results for 104 consecutive radical prostatectomy cases with no prior treatment. Clinically insignificant cancer in 104 prostatectomy specimens was found to occur at 4.8, 10.6, 15.4 and 26.9% for tumor doubling times of 2, 3, 4 and 6 years, respectively. Assuming a 2-year doubling time with clinically insignificant cancer excluded, only 36.4% of significant cancers could be considered potentially curable and with a 3-year doubling time, 32.3%. For 4- and 6-year doubling times, only 30.7 and 25.0% of the clinically insignificant cancers were potentially curable, respectively. Approximately half of these insignificant cancers were clinically stage T1c disease. In all stage T1c cases, 8.8-47.1% was considered insignificant, depending on tumor doubling time. Patient life expectancy and tumor doubling time significantly determine the outcome of treatment for prostate cancer, especially in elderly males with higher risk of mortality. The outcome of radical prostatectomy is less satisfactory with these factors taken into consideration. Many patients with stage T1c disease may eventually prove to require no treatment.

Aged↗
PubMed1996

Deoxyribonucleic acid ploidy status as no basis for pathologic stage prediction in clinically resectable prostate cancer.

OBJECTIVES: Assessment of deoxyribonucleic acid (DNA) ploidy status of a tumor as a means for predicting pathologic stages in prostate cancer. METHODS: DNA ploidy of each focus of a cancer in 70 radical prostatectomy specimens was determined by nuclear image analysis. DNA ploidy was compared with the pathologic features of tumors. RESULTS: One hundred three individual cancers in 70 patients were used for DNA ploidy analysis. Of these, 39 (38%) were diploid and 64 (62%), nondiploid. DNA ploidy was weakly correlated with increase in tumor volume (P = 0.049) but not tumor grade. The relationship between DNA content and extraprostatic spread was not statistically significant. Increase in tumor volume and grade promoted extraprostatic spread more than nondiploidy, as shown by multivariate analysis. CONCLUSIONS: The incidence of a nondiploid cell population in a tumor focus in prostate cancer is essentially the same, at least for Americans and Japanese. DNA ploidy of a tumor cannot serve as a means of pathologic stage prediction in clinically resectable prostate cancers, contrary to many previous studies. Thus, DNA content analysis would be of no use for deciding on the treatment strategy of prostate cancer.

DNA, Neoplasm↗
PubMed1996

Significance of preoperative parameters for predicting tumor volume in nonpalpable prostate cancer.

Preoperative parameters were assessed for their usefulness in predicting tumor volume in 26 cases of nonpalpable prostate cancer. The number of positive biopsy cores was found to be the parameter which predicted most accurately tumor volume in surgical specimens. All 14 patients with multiple positive cores had an index tumor of 0.5 cm3 or more in radical prostatectomy specimens. Only six tumors with a single positive core were substantial. Three of the patients showed a serum level of prostate specific antigen (PSA) of 4.0 ng/ml or more. The pathological stage and prostatectomy Gleason sum could not be predicted accurately by this variable (P>0.05). To predict index tumor volumes of 1.0 cm3 or greater, stepwise logistic regression analysis was conducted, and on the basis of the results it was possible to single out multiple positive biopsies as the only significant variable. The number of positive biopsies appeared reliable for predicting tumor volume of surgical specimens in cases of nonpalpable disease. The presence of significant tumors despite "normal" levels of PSA warrants further investigation of variables that can predict such prostate cancers. An adequate model for predicting significant tumors in oriental male populations should be established using samples of larger size.

Biopsy, Needle↗
PubMed1996

Preoperative serum prostate-specific antigen, clinical stage and Gleason sum as basis for predicting final pathological stage in Japanese patients with prostate cancer.

By logistic regression analysis and log-likelihood ratio chi-square test, the usefulness of preoperative variables (prostate specific antigen [PSA], clinical stage and biopsy Gleason sum) for predicting the final pathological stage was assessed in 77 patients with clinically resectable prostate cancers. Pathologically, 32 (41.6%) had organ-confined disease. Extracapsular extension was found in 41 (53.2%), seminal vesicle involvement in 30 (39.0%), positive pelvic lymph nodes in 10 (13.0%) and a positive surgical margin in 27 (35.1%). Each preoperative variable was found to be significantly associated with the final pathological stage. Any combination of these variables was more predictive for extraprostatic disease, compared with each individual variable. Extraprostatic spread was found more frequently in patients with lower serum PSA in this Japanese elderly male population compared with North American males. These preoperative variables considered in combination may provide valuable information for management decisions related to prostate cancer. Serum PSA alone cannot reliably predict pathological stage on an individual basis except in patients with a PSA level of 20 ng/ml or greater. The high incidence of extraprostatic spread at intermediate PSA underscores the importance of selecting an ideal cutoff value for PSA-based screening in a Japanese male population.

Aged↗
PubMed1996

[Membranous nephropathy in Japanese children].

Since 1973, 15 patients, consisting of 8 boys and 7 girls, were diagnosed as having membranous nephropathy (MN). The average age at detection was 8.2 years (2-14 years). The presenting symptom was edema in 1, pyrexia in 1 and upper respiratory infection in 1 case, in the all other cases, abnormal urinalysis was detected by the school or chance urinalysis. Surface antigen of hepatitis B virus (HBs) was positive in 6 patients and negative in 9. Anti-nuclear antibody (ANA) was positive in 3 and negative in 11. In one patient, ANA was not tested. One patient who was negative for ANA was diagnosed as having SLE 4 years later. At the last follow-up, 10 patients continued to have urinary abnormalities. Among these was one case positive for HBs antigen who went into end-stage renal failure. In the other 14 patients, the serum creatinine level was below 1.4 mg/dl. All patients showed a normal mesangium or mild mesangial proliferation. The patient diagnosed as having SLE. 4 years later showed mesangial deposits at the first renal biopsy. In our experience, most patients with MN were detected by the school or chance urinalysis and six of the these had positive HBs antigen. Lupus nephritis must be ruled out in making a diagnosis of idiopathic MN.

Adolescent↗
PubMed1995

Early detection of prostate cancer. Results of a prostate specific antigen-based detection program in Japan.

BACKGROUND: Prostate cancer increasingly is becoming a medical problem in Japan. To maximize the chance for cure, extensive effort is being made to detect prostate cancer while confined to the gland. METHODS: Determination was made of serum prostate specific antigen (PSA) in the early detection of prostate cancer in an Asian male population aged 55 years or older. Recommendation for biopsy was based solely on this parameter when its value exceeded 2.0 ng/ml in IMx immunoenzymetric assay. RESULTS: Of 1189 men, 150 (12.6%) had elevated values. The proportion of males with serum PSA greater than 4.0 ng/ml was only 3.4%. Of the 99 males who underwent ultrasound-guided biopsies, 16 cancers were detected, a cancer detection rate of 1.3%. Most of these (81.3%) were clinically localized cancers. Seven patients with cancer had serum PSA levels below 4.0 ng/ml including 5 less than 3.0 ng/ml. These tumors would have been overlooked if the conventional cutoff levels of 4.0 ng/ml had been applied. Radical prostatectomy was conducted on 13 patients. All had histologic features of clinically significant cancer and 69.2% were pathologically confined within the gland. CONCLUSIONS: Elderly Asian males appear to have lower serum PSA than their Western counterparts. The optimal cutoff of serum PSA for early detection should be examined further in Asian male populations. Differences in the incidence of prostate cancer between ethnic groups may have been overestimated in previous studies owing in part to unawareness by the physician and general public. Though the frequent use of more sophisticated diagnostic modalities will likely disclose greater numbers of prostate cancers in Japan, whether early detection reduces mortality by minimizing risk of death from cancer remains a point to be determined.

Aged↗