Antioxidants in the Treatment of Cancer.

Several clinical trials have produced conflicting results regarding the benefit of antioxidants in cancer therapy thus questioning the incorporation of these substances in standard treatment regimens. Vitamins E and C, selenium, carotenoids, lycopene, soy products, and green tea extract are a few substances with antioxidant properties that have been studied in detail. This article reviews the results generated over the last 20 years through in vitro and in vivo studies in various types of cancers and stages of cancer treatment. Despite the commercial popularity and the multitude of studies examining antioxidant therapy, the true role of antioxidants is yet to be determined, requiring further investigation into its propagative, causal, or protective nature.

A Phase II Trial of AEZS-108 in Castration- and Taxane-Resistant Prostate Cancer.

BACKGROUND: AEZS-108 (zoptarelin doxorubicin) is a cytotoxic hybrid molecule consisting of doxorubicin covalently coupled with a luteinizing hormone-releasing hormone (LHRH) analogue, which selectively targets doxorubicin to tumor cells expressing LHRH receptors. We report the clinical efficacy of AEZS-108 in a phase II trial in men with metastatic castrate-resistant prostate cancer who had disease progression after taxane-based chemotherapy. PATIENTS AND METHODS: Patients received AEZS-108 210 mg/m2 intravenously every 3 weeks. The primary end point was clinical benefit defined as nonprogression at 12 weeks with no dose-limiting toxicities (DLTs) or other toxicities requiring termination of treatment. Secondary end points included response rate, pain response, progression-free survival (PFS), and overall survival (OS). Circulating tumor cells (CTCs) were captured and tested for LHRH receptors, as well as for internalization of AEZS-108 using autofluorescence. RESULTS: Twenty-five patients were enrolled; 20 patients had at least 1 measurable lesion at baseline. Patients received a median of 5 cycles (range, 1-9) and 44% of patients received at least 6 cycles with 2 patients who completed ≥ 8 cycles. Considering clinical benefits, 13 patients (52%) remained progression-free at 12 weeks with no DLT or other toxicities requiring termination of treatment. For clinical response according to Response Evaluation Criteria in Solid Tumors version 1.1 criteria, 1 patient (4%) experienced a confirmed partial response (PR) within 12 weeks, 14 patients (56%) had stable disease (SD), and 8 patients (32%) had disease progression. For maximal prostate-specific antigen (PSA) response, 1 patient (4%) experienced a confirmed PR within 12 weeks, 21 patients (84%) had SD, and 3 patients (12%) had disease progression as denoted by their best PSA response. Pain improved in 13 (59%) patients. The median PFS was 3.8 months (95% confidence interval [CI], 2.1-4.4), and median OS was 6.0 months (95% CI, 4.2-10.1) with a median follow-up of 16.1 months (range, 3.2-36.1). Baseline CTC enumeration was an independent predictor of OS but not PFS. CONCLUSION: AEZS-108 showed activity in patients who were pretreated, a subset typically very difficult to treat, and maintained an acceptable safety profile.