tetrathiomolybdate and Prostatic-Neoplasms

Although anti- angiogenesis strategies have generated much enthusiasm for therapeutic applications, it is still unknown whether they would be feasible for prevention. The possibility of interfering very early in tumor progression by modulating the cancer angiogenic switch is appealing. In this chapter, we review progress with in vitro and in vivo models that show that anti-angiogenic interventions may be amenable to long- term chemopreventive measures. In particular, some approaches that are nearly ready for major applications are anti-oxidant nutraceuticals and copper deficiency. We use these strategies as paradigms of how to make progress in this difficult but important area of translational research.

Topics: Angiogenesis Inhibitors; Animals; Anticarcinogenic Agents; Antioxidants; Breast Neoplasms; Carotenoids; Cell Transformation, Neoplastic; Chelating Agents; Copper; Dietary Supplements; Female; Flavonoids; Head and Neck Neoplasms; Humans; Lung Neoplasms; Male; Molybdenum; Neoplasms; Neovascularization, Pathologic; NF-kappa B; Phenols; Polyphenols; Prostatic Neoplasms; Reactive Oxygen Species

ATN-224 (choline tetrathiomolybdate) is an oral Cu(2+)/Zn(2+)-superoxide dismutase 1 (SOD1) inhibitor with preclinical antitumor activity. We hypothesized that ATN-224 may induce antitumor effects as an antiangiogenic agent at low dose-levels while possessing direct antitumor activity at higher dose-levels. The objective of this study was to screen its clinical activity in patients with biochemically recurrent hormone-naïve prostate cancer.. Biochemically-recurrent prostate cancer patients with prostate specific antigen doubling times (PSADT) < 12 months, no radiographic evidence of metastasis, and no hormonal therapy within 6 months (with serum testosterone levels > 150 ng/dl) were eligible. ATN-224 was administered at 2 dose-levels, 300 mg (n = 23) or 30 mg (n = 24) daily, by way of randomization. PSA progression was defined as a ≥ 50% increase (and >5 ng/ml) in PSA from baseline or post-treatment nadir. Endpoints included the proportion of patients who were free of PSA progression at 24 weeks, changes in PSA slope/PSADT, and safety. The study was not powered to detect differences between the 2 treatment groups.. At 24 weeks, 59% (95% CI 33%-82%) of men in the low-dose arm and 45% (95% CI 17%-77%) in the high-dose arm were PSA progression-free. Median PSA progression-free survival was 30 weeks (95% CI 21-40(+)) and 26 weeks (95% CI 24-39(+)) in the low-dose and high-dose groups, respectively. Pre- and on-treatment PSA kinetics analyses showed a significant mean PSA slope decrease (P = 0.006) and a significant mean PSADT increase (P = 0.032) in the low-dose arm only. Serum ceruloplasmin levels, a biomarker for ATN-224 activity, were lowered in the high-dose group, but did not correlate with PSA changes.. Low-dose ATN-224 (30 mg daily) may have biologic activity in men with biochemically-recurrent prostate cancer, as suggested by an improvement in PSA kinetics. However, the clinical significance of PSA kinetics changes in this patient population remains uncertain. The absence of a dose-response effect also reduces enthusiasm, and there are currently no plans to further develop this agent in prostate cancer.

Topics: Aged; Aged, 80 and over; Diarrhea; Disease Progression; Disease-Free Survival; Dose-Response Relationship, Drug; Enzyme Inhibitors; Fatigue; Humans; Kaplan-Meier Estimate; Leukopenia; Male; Middle Aged; Molybdenum; Nausea; Neoplasm Recurrence, Local; Prostate-Specific Antigen; Prostatic Neoplasms; Superoxide Dismutase; Time Factors; Treatment Outcome

Preclinical studies suggest antiangiogenesis strategies may be effective in the treatment of prostate cancer. In tumor models, the copper-chelating agent tetrathiomolybdate (TM) has been shown to be antiangiogenic. We evaluated the antitumor activity of TM in patients with hormone-refractory prostate cancer (HRPC).. Nineteen patients with asymptomatic HRPC enrolled. Copper depletion was monitored using serum ceruloplasmin levels. Once the target ceruloplasmin level of 5-15 mg/dl was attained, patients underwent staging evaluation. Patients were reassessed every 12 weeks, and TM was continued until they developed evidence of disease progression or intolerable toxicity. Prostate-specific antigen and levels of vascular endothelial growth factor, basic fibroblast growth factor, interleukin (IL)-6 and IL-8 were measured at study entry, at the time of copper depletion, and monthly while on therapy.. Seventeen of 19 patients achieved copper deficiency on TM therapy. Of the 16 evaluable patients, 14 developed progressive disease, 1 discontinued therapy because of toxicity and 1 patient opted to discontinue therapy because of rising prostate-specific antigen level without objective evidence of progressive disease. Levels of vascular endothelial growth factor, IL-6 and IL-8, but not basic fibroblast growth factor, were elevated when compared to normal controls prior to TM therapy, but there was no significant change during therapy. There was no correlation between prostate-specific antigen and levels of angiogenesis factors.. Copper depletion with TM did not delay disease progression in patients with asymptomatic metastatic HRPC.

Topics: Adenocarcinoma; Aged; Angiogenesis Inhibitors; Biomarkers; Ceruloplasmin; Chelating Agents; Copper; Disease Progression; Fibroblast Growth Factor 2; Humans; Interleukin-6; Interleukin-8; Male; Middle Aged; Molybdenum; Neoplasm Metastasis; Prostatic Neoplasms; Vascular Endothelial Growth Factors