Active surveillance criteria for prostate cancer: can they be applied to Japanese patients?

Prostate-specific antigen screening has significantly increased the percentage of men who are diagnosed with low-risk prostate cancer. All men undergoing retropubic radical prostatectomy for primary treatment of prostate cancer from April 2004 to September 2010 in our hospital were examined in order to determine whether active surveillance criteria could be applied to Japanese men. From pathological data of prostate biopsies, whether these men met five published criteria for active surveillance (Johns Hopkins Medical Institution, Prostate Cancer Research International: Active Surveillance Study, University of California, San Francisco, Toronto and Kakehi criteria) was evaluated. Men who met any of the criteria had a statistically significant lower extracapsular extension rate and organ-confinement rate. From the view of the possibility of Gleason upgrading and organ-confinement rate, the Johns Hopkins Medical Institution and Prostate Cancer Research International: Active Surveillance Study criteria showed to be appropriate for Japanese patients. However, the present study had limitations of selection bias and a limited number of cases.

Evaluation of docetaxel plus estramustine in the treatment of patients with hormone-refractory prostate cancer

OBJECTIVES

To investigate the feasibility and efficacy of docetaxel-based chemotherapy in patients with hormone-refractory prostate cancer (HRPC).

METHODS

Forty-six consecutive HRPC patients treated between January 2003 and March 2008 were included in this analysis. Docetaxel was given at a dose of 35 mg/m(2) twice every 3 weeks and oral estramustine concurrently for three consecutive days during weeks 1 and 2 of each cycle. During each treatment week, the dose of estramustine was 1260 mg on the first day, 980 mg on the second day and 840 mg on the third day. Patients were premedicated with 4 mg twice a day of oral dexamethasone for three consecutive days. Treatment was continued until evidence of disease progression or unacceptable toxicity. Prostate-specific antigen (PSA) levels were evaluated at least once every 4 weeks.

RESULTS

Patients received a median of three cycles of chemotherapy. Of the evaluable 46 patients, 25 (54%) had a >or=50% PSA decline and 12 (26%) had a >or=75% PSA decline. Median time to PSA progression and overall survival time were 10.1 and 27.0 months, respectively. Median follow-up was 15.0 months. Major severe toxicities were grade 3 or 4 leukopenia in five (11%) patients. Mild toxicities included grade 1 or 2 nausea in eight (17%) patients. Two patients could not continue the treatment because of interstitial pneumonitis and a gastric hemorrhage, respectively.

CONCLUSIONS

Docetaxel plus estramustine chemotherapy represents an active and well tolerated treatment for Japanese HRPC patients.

The long-term outcome of cystinuria in Japan

Recurrence of growth of urinary stone is frequently observed during the clinical course of cystinuria patients. The aim of the present study is to examine the long-term outcome of cystinuria in Japan and clarify the effects of medical treatment on urinary stone. Thirty-one patients with cystinuria who had been followed up longer than 6 months were included. The follow-up period was 6-264 months with a mean of 89.5 months. Stone event was defined as appearance of new stone or radiological evidence of stone growth. All patients were managed with forced hydration and urine alkalization. Twenty-eight patients were treated with administration of thiol such as D-penicillamine or alpha-mercaptopropionylglycine. Stone events per year ranged from 0 to 1.09 with a median of 0.09. Stone events per patient-year was 0.19 for all patients. The average urinary cystine concentration during treatment in the favorable outcome group (stone events per year < 0.3) was lower that that in the unfavorable outcome group (stone events per year >/=0.3); 221.2 +/- 75.2 vs. 303.3 +/- 93.5 mg/l, although the difference was not statistically significant. Prognosis of urinary stone in Japanese patients with cystinuria was relatively good with large variation. The medical treatment to reduce urinary cystine concentration would be useful for the management of cystinuria.

Binding of dihydrotestosterone, R 1881 and R 5020 in cytosols from normal, benign hypertrophic and cancerous human prostates

The binding of dihydrotestosterone, R 1881 and R 5020 was examined in cytosols of normal, benign hypertrophic and cancerous tissues of the human prostates. Almost all samples obtained by open operation showed high affinity binding to these ligands. Dissociation constants of the binding to these ligands were approximately 10(-9) M irrespective of the pathological state of the prostates. Maximum binding sites for dihydrotestosterone seemed to be greater in normal tissues than in the pathological ones. However, maximum binding sites for R 1881 and R 5020 were not significantly different among the normal and pathological prostates examined in the present study. Moreover, some correlation was observed between the maximum binding sites for R 1881 and those for R 5020. The samples resected by TUR seemed to be inadequate for analyses of androgen binding.

Androphilic proteins in the human prostate

Dihydrotestosterone-binding protein in cytosols from human prostates was different from the R1881- and R5020-binding proteins. The R1881- and R5020-binding proteins in the cytosol were very similar and most of the binding sites for R1881 were capable of binding R5020. However, nuclear extracts showed equal binding to dihydrotestosterone and R1881, but not to R5020, suggesting that there might not be a progestin receptor in the human prostate. Maximum binding sites to dihydrotestosterone, R1881, and R5020 in cytosols were very similar among "normal" and pathological prostates except that dihydrotestosterone binding was higher in "normal" prostates than in the pathological ones. Histochemically, R1881-binding was observed in the epithelial cells and in malignant cells, but not in the stroma.

Cell kinetic studies on androgen-dependent mouse mammary tumor and subline with altered dependency

Cell kinetic study was performed using labeled mitosis method to compare growth characteristics of androgen-dependent mouse mammary tumor (SC115), which grows only in males, and its subline (Chiba subline No. 1), which has partially lost its dependency during passages through males and grows also in females, although at a slower rate. The subline, compared to the original tumor, showed higher growth fraction irrespective of whether inoculated into a male or a female. The cell cycle of the subline was faster in males than in femlaes due to acceleration of Gl phase and this trend was reflected in the cell production rate and overall rate of growth. The slower growth in females was restored by the administration of testosterone. However, growth fraction was rather in the inverse relationship with the cell production rate and this fact suggested that androgen-deprived conditions do not support survival of non-cycling cells. Primary effect of androgenic environment on this subline was considered to be the reduced length of Gl phase.