A randomized, double-blind, placebo-controlled trial to evaluate the role of curcumin in prostate cancer patients with intermittent androgen deprivation

Background: The anti-cancer activities of curcumin are well-documented from preclinical studies using prostate cancer models. Our objective was to evaluate the anti-cancer activity of oral curcumin in patients with prostate cancer. Methods: This randomized, double-blind, placebo-controlled trial was performed on patients with prostate cancer who received intermittent androgen deprivation (IAD). Participants who finished the first on-treatment period of IAD were randomized into a curcumin or placebo group. The patients took oral curcumin (1440 mg/day) or placebo for six months and were followed up until the beginning of the second on-treatment. The primary end-point was duration of the first off-treatment. The secondary end-points were change in PSA and testosterone levels during 6 months, PSA progression rate, and health-related quality of life (HRQOL) scores at 6 months. Safety assessments included adverse event, adverse drug reaction, and serious adverse event. Results: A total of 97 participants were randomized 1:1 to curcumin (n = 49) and placebo (n = 48) groups. Among them, 82 patients (84.5%) were evaluable for the analysis (39 and 43 patients in the curcumin and placebo groups, respectively). The median off-treatment duration was 16.3 months (95% confidence interval [CI] 12.3-20.3 months) and 18.5 months (95% CI 12.5-23.0 months) in the curcumin and placebo groups, respectively. There was no significant difference in the curve of off-treatment duration between the two groups (P = 0.4816). The proportion of patients with PSA progression during the active curcumin treatment period (6 months) was significantly lower in the curcumin group than the placebo group (10.3% vs 30.2%, P = 0.0259). The change of PSA, testosterone levels during 6 months, and HRQOL scores at 6 months were not different between curcumin and placebo groups. Adverse events were higher in the placebo group (16 of 46 vs 7 of 45 patients, P = 0.0349). No significant differences in the adverse drug reaction were found between the two groups. Conclusions: Six months’ intake of oral curcumin did not significantly affect the overall off-treatment duration of IAD. However, PSA elevation was suppressed with curcumin intake during the curcumin administration period. Curcumin at this dose was well tolerated and safe.