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Suramin has been shown to have an effect on bone resorption in in vitro models. It is not clear if a similar effect is seen in patients treated with suramin. The clinical effect of suramin treatment on total serum calcium was examined in two groups of patients with hormone-refractory prostate cancer. In all, 28 patients in group 1 were examined within 2 weeks before and 2 weeks after suramin treatment and 72 patients in group 2 were examined within 2 weeks before, during, and after treatment with suramin. In addition, calcium controls spiked with suramin were run in three different commercially available assays for evaluation of the effect of suramin dose on calcium determination. Group 1 patients showed a decrease in serum calcium after treatment with suramin. The mean uncorrected serum calcium level was 2.29 +/- 0.025 mmol/l before treatment and 2.09 +/- 0.025 mmol/l after treatment (P < 0.0001, paired Wilcoxon test). The mean serum calcium value corrected for albumin was 2.33 +/- 0.02 mmol/l before treatment and 2.24 +/- 0.02 mmol/l after treatment (P = 0.0022, paired Wilcoxon test). Group 2 patients also displayed a decrease in serum calcium after treatment with suramin. The mean baseline value was 2.23 mmol/l (median 2.26 mmol/l, range 1.20-2.54 mmol/l). The mean level of serum calcium corrected for albumin as determined at the end of treatment was 2.14 mmol/l (median 2.16 mmol/l, range 0.98 2.46 mmol/l). In all, 48 patients for whom pre- and post-treatment values were available for analysis displayed a median calcium decrease of 0.09 mmol/l (P = 0.0005, Wilcoxon signed-rank test for the null hypothesis of no change). For 68 patients in group 2, data on serial serum calcium measurements during treatment were available for analysis. A projected median decrease in serum calcium of 0.06 mmol/l (range 0.43 to 0.72 mmol/l) over an 8-week interval of suramin therapy was found. Overall, 47 of the 68 slopes were negative (P = 0.0022, Wilcoxon signed-rank test). Nine patients were treated with suramin for less than 6 weeks. These patients' calcium levels were significantly higher than those of 50 patients treated for longer periods (median value 2.24 versus 2.16 mmol/l, P = 0.035, Wilcoxon rank-sum test). No correlation was found between suramin dose and calcium level using the Kodak Ektachem, Hitachi 914, or Synchron Clinical System CX3 method. In conclusion, suramin treatment was consistently associated with decreases in serum calcium in two groups of patients with hormone-refractory cancer. Suramin placed in calcium controls did not affect calcium determination using three commercially available methods.

Background: Combined androgen blockade (CAB) (medical or surgical castration plus antiandrogen therapy) is considered by many to be the optimal endocrine maneuver for patients with metastatic prostate carcinoma. When progression occurs after CAB, the discontinuation of the antiandrogen is recommended. The authors present a patient that had a clinical complete response to flutamide withdrawal plus hydrocortisone that, at last follow-up, had been maintained for more than 46 months., Methods: A 71-year-old man with a positive family history of prostate carcinoma presented in 1989 with urinary frequency and a suspicious digital rectal examination. He was found to have a poorly differentiated adenocarcinoma (Gleason 4+4). He was started on CAB and his prostate specific antigen (PSA) concentration declined from 96 ng/mL to the normal range and was maintained for the next 24 months. In 1991 his PSA began to rise, and reached 64 ng/mL by 1993. The patient was enrolled on a clinical trial that discontinued the flutamide administration and hydrocortisone was initiated., Results: Physical examination at the time of enrollment was unremarkable. His PSA declined to below the limits of detection after this maneuver and at last follow-up had been maintained there for more than 46 months. In 1995, the patient underwent a repeat biopsy of the prostate and all six tissue cores were negative for carcinoma. At last follow-up in December 1996, the patient had no evidence of disease and was being followed routinely; however, the authors were continuing treatment with testicular suppression (leuprolide) plus hydrocortisone., Conclusions: The authors believe the residual androgens and steroids produced by the adrenal cortex play a meaningful role in prostate carcinoma cell proliferation. Based on this case and data from trials supporting the activity of flutamide withdrawal plus adrenal suppression, it appears reasonable to evaluate prospectively the discontinuation of antiandrogen versus antiandrogen withdrawal plus adrenal suppression in individuals failing CAB.

Background: Suramin is an anthelmintic drug that recently has been shown to have clinical efficacy in the treatment of patients with some advanced malignancies, including prostate carcinoma. The current study was done to assess the effect of suramin at clinically relevant doses on the growth in culture of a human prostatic carcinoma cell line, PC-3., Methods: The antiproliferative effect of varying doses of suramin on PC-3 was assessed. Northern blot analysis was done to assess the potential changes in genetic expression at different times after the initiation of treatment., Results: Suramin inhibited the proliferation of PC-3 in a dose-related manner (concentration range, 30-300 microM). Compared with fetal calf serum 2%, when the cells were grown in fetal calf serum 10%, higher concentrations of suramin were required to inhibit tritiated thymidine incorporation. When grown in RPMI without supplement, the PC-3 cell number remained the same. When 100 microM suramin was included, the cell number decreased. By contrast, when RPMI was supplemented with insulin, transferrin, and selenium (ITS), PC-3 grew well. The inhibition of the proliferation of PC-3 cells by suramin was decreased when ITS were added to the cells grown under serum-free conditions., Conclusions: These results were consistent with the hypothesis that in vitro inhibition of the growth of PC-3 cells by suramin may be caused, at least in part, by the growth factor antagonism of the drug. In fetal calf serum 2%, the suramin inhibition was reversible after 3 days. If the treatment was extended to 6 days, however, the PC-3 cells were unable to recover. Cell-cycle analysis revealed that, after 6 days of treatment, there was a decrease in the number of cells in G1 that corresponded with an increased number of cells in G2/M. This suggested that critical antineoplastic events were occurring during this time. Molecular analysis did not detect any altered expression of actin, transforming growth factors alpha or beta, or histone compared with untreated control samples.

Purpose: Suramin is known to inhibit the growth of malignant prostate carcinoma cells in vitro. This led us to evaluate the effectiveness of suramin in the treatment of 38 patients with prostate carcinoma refractory to hormone therapy., Patients and Methods: Suramin was administered by continuous infusion at a rate designed to reach a peak of 300 micrograms/mL at the end of 14 days. Patients were given 8 weeks to recover from any toxicity before beginning the second cycle. Subsequent cycles were administered in the same manner except the starting dose rate was 280 mg/m2., Results: In 17 patients with measurable soft tissue disease, three had complete disappearance of soft tissue disease for 4, 5, and 11 months, whereas three patients had a greater than or equal to 50% decrease in the sum of the products of the diameters of all measurable disease for greater than or equal to 1 month. Of these 17 patients, pretreatment prostate-specific antigen (PSA) decreased by 75% or more in five (29%) and normalized in one (6%). The remaining 21 patients had disease limited to bone, and only one of these experienced resolution of more than 50% of all lesions on bone scan. Of these 21 patients, pretreatment PSA decreased by 75% or more in eight (38%) and normalized in five (25%). Median time to progression for all patients was 26.3 weeks, and median survival was 42.3 weeks. Patients with bone involvement alone exhibited a better survival than patients with soft tissue involvement (P2 = .02). Survival was strongly correlated (P2 = .0001) with a decline in the pretreatment PSA of greater than or equal to 75% by the eighth week on therapy, with nearly an 85% survival at 1 year compared with a 20% survival for those whose pretreatment PSA did not decline by that amount., Conclusion: We conclude that suramin is an active agent in hormone-refractory prostate carcinoma.

Suramin and related compounds, in view of their growth factor and enzyme binding properties, represent in many respects a novel approach to the treatment of cancer. Although in this preliminary analysis of suramin use in the treatment of metastatic prostate cancer, the objective response rate does not appear impressive, much work still needs to be done to optimize suramin's administration to patients and to elucidate its various postulated mechanisms of action. The development of related compounds with more specific enzyme and growth factor antagonist properties is under way.

Endometrial carcinoma of the prostatic utricle previously was believed to be of müllerian origin. We report 2 cases studied by ultrastructural and immunoperoxidase techniques. Our results, as well as those presented by others, demonstrate the prostatic origin of this tumor.

Cells of adenocarcinoma of the prostate (ACP) are infrequently shed in urine. We examined the clinicopathologic features of 22 patients with ACP and tumor cells in urine. Patients typically were clinical stage C or D and had hematuria (13 cases, 59%) and/or obstruction (11 cases, 50%). Prostatic palpation or instrumentation preceded collection of 15 urine specimens. Histologically, tumors were high grade (Gleason score 7-10) and extensive, with involvement of prostatic ducts and acini (10 cases, 45%) and prostatic urethra (5 cases, 23%). Cytologically, the background was clean, and neoplastic cells appeared singly, in loose clusters, as large "casts," or, rarely, in papillary structures. The cells were small, round to oval, with a moderate amount of finely granular or vacuolated cytoplasm; nuclei were generally round with a thin, often irregular membrane, finely granular chromatin, and a single prominent nucleolus. Immunoperoxidase staining for prostatic acid phosphatase and prostate-specific antigen was useful in distinguishing ACP from transitional cell carcinoma.