Abstract 3564: A Phase II randomized trial of lycopene-rich tomato extract among men with high-grade prostatic intraepithelial neoplasia (HGPIN)

Abstract

Abstract Evidence from observational epidemiology, animal models and cell culture experiments suggest that tomato foods or other sources of lycopene might inhibit the development of prostate cancer. Clinical trial data, however, is thus far sparse, especially in relation to effects on benign prostate tissue. We conducted a 6-month repeat biopsy trial in men with HGPIN who were randomly assigned to consume either placebo or capsules of Lyco-Mato®, a tomato oleoresin containing 30 mg/day of lycopene. All participants were encouraged to avoid lycopene containing foods and supplements while on-study. Here we report results for serum lycopene, PSA and IGF proteins, and initial results for immunohistochemical analysis of markers for proliferation (minichromosome maintenance protein 2, MCM-2) and cell cycle inhibition (p27). Biopsy slides were stained using monoclonal antibodies for both markers and scoring was performed using an Aperio whole-slide digital microscope and scoring algorithms plus Genie® pattern recognition software for defining the epithelial compartment. Serum lycopene was determined by LC-MS-MS; PSA, IGF-1 and IGFBP3 were measured by enzyme immunoassay. Primary analyses compared treatment groups using a paired t test for the change in each endpoint. A total of 58 men completed the trial (26 active, 32 placebo); assignment groups were equivalent at baseline in terms of age, race, serum lycopene, PSA, IGF-1 and IGFBP3. Serum lycopene increased by 0.550 μmol/L (77%) in the active treatment group and declined by 0.288 μmol/L (19%) in the placebo group. We observed no meaningful differences in serum PSA, IGF-1 or IGFBP3 concentrations between groups. There were also no differences between groups in the percentages of epithelial nuclei expressing MCM-2 or the scoring index combining percentage with nuclear stain intensity. Similar null results were seen for staining with the CDK2 inhibitor p27. We conclude that despite a large difference in serum lycopene concentrations following intervention, no effects were apparent at 6 months on PSA or IGF proteins. The IHC results, although preliminary, suggest that treatment had no effect on epithelial cell proliferation or cell cycle inhibition via p27. Further analyses, including analysis of additional IHC markers, are currently underway. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3564. doi:1538-7445.AM2012-3564