Concomitant botanical medicine use among patients participating in commercial prostate cancer trials.

OBJECTIVES: Patients with cancer frequently use botanical medications. The concomitant use of such medications by patients on commercial trials has not been well-described, despite the importance of these trials for evaluating the safety and efficacy of new agents. We sought to describe the use of botanical medications taken by patients with prostate cancer enrolled on global commercial trials. DESIGN: Retrospective study. SETTING: Regulatory repository of commercial clinical trial data. INTERVENTIONS: Anti-cancer therapy. MAIN OUTCOME MEASURES: Botanical and medication use data were pooled across six international commercial randomized trials for metastatic prostate cancer with detailed information on medication and indications. Botanical products were considered to have potential for drug interaction if they led to a change in drug exposure in human trials. Potential for interaction was ascertained by PubMed review. Descriptive statistics were used for analysis. RESULTS: Of 7318 enrolled patients, 700 (10 %) reported botanical use at any time and 653 (9%) reported use of botanical products while on trial. Nearly half of botanical product types were not classified by plant (43 %). The highest proportion of botanical use was among patients in Asian countries (32 %), followed by patients in North America (13 %). Eighty-six different types of botanical products were used; of these, nineteen had a patient-reported anti-cancer indication. CONCLUSIONS: Botanical medicine use among patients with prostate cancer in commercial trials is moderate, although it varies by region. Practitioners should be aware of the use of botanical interventions in a clinical trial context.

Change in PSA velocity is a predictor of overall survival in men with biochemically-recurrent prostate cancer treated with nonhormonal agents: combined analysis of four phase-2 trials.

BACKGROUND: Multiple phase-2 trials in men with biochemically-recurrent prostate cancer (BRPC) have assessed the impact of nonhormonal agents on PSA kinetics. We have previously demonstrated that changes in PSA kinetics correlate with metastasis-free survival; however, it is unknown whether these changes also correlate with overall survival (OS). METHODS: We performed a combined retrospective analysis of 146 men with BRPC treated on phase-2 trials using one of four investigational drugs: lenalidomide (n=60), marimastat (n=39), ATN-224 (n=22) and imatinib (n=25). We examined factors influencing OS, including within-subject changes in PSA kinetics (PSA slope, PSA doubling time and PSA velocity), before and 6 months after treatment initiation. RESULTS: After a median follow-up of 83.1 months, 49 of 146 men had died. In univariate Cox regression analysis, two factors were associated with OS: baseline PSA velocity and change in PSA velocity on therapy. In a landmark multivariable model, stratified by study (which controlled for age, Gleason score, type of local therapy and use of androgen-deprivation therapy prior to metastases), baseline PSA velocity and increase in PSA velocity on therapy remained independent predictors of OS. Median OS for men with an increase in PSA velocity on treatment was 115.4 months and was not reached for men with a decrease in PSA velocity (hazard ratio=0.47, 95% confidence interval 0.25-0.88; P=0.02). CONCLUSIONS: This hypothesis-generating study suggests that within-subject changes in PSA velocity after initiation of nonhormonal therapy may correlate with OS in men with BRPC. If validated in prospective trials, change in PSA velocity may represent a reasonable intermediate end point for screening new agents in these patients.