IGFs & Metabolic Endocrinology Group, Translational Health Sciences, Bristol Medical School, Southmead Hospital.
National Institute for Health Research (NIHR) Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol.
Eur J Cancer Prev. 2019 Nov;28(6):569-575. doi: 10.1097/CEJ.0000000000000502.
Whether prostate cancer (PCa) may be preventable by dietary interventions can be assessed in randomized trials using intermediate biomarkers of cancer risk or progression. We investigated whether lycopene or green tea modify circulating insulin-like growth factor (IGF) peptides in men at increased risk of PCa. Participants (aged 50-69 years) in one centre in the UK wide PCa testing and treatment trial (ProtecT) with prostate specific antigen between 2.0 and 2.95 ng/ml or negative biopsies, were randomized to daily lycopene (n = 44 assigned 15 mg capsules/day; 44 assigned a lycopene-rich diet; 45 assigned placebo) and green tea (n = 45 assigned 600 mg/day epigallocatechin gallate; 45 assigned green tea drink; 43 assigned placebo) for 6 months. The interventions significantly elevated the primary outcomes, serum epigallocatechin gallate and lycopene at 6 months of follow-up. We report here an exploratory analysis in which serum IGF-I, IGF-II, IGF binding protein (BP)-2 and IGFBP-3 were measured at baseline and 6 months of postintervention. A total of 133 men were randomized (34% of eligible men approached) and 130 had follow-up IGF peptides (98%). In intention-to-treat analyses, there was only weak evidence that lycopene or green tea influenced some aspects of serum IGF-I, IGF-II, IGFBP-2 or IGFBP-3. In men randomized to lycopene supplements, IGFBP-2 was nonsignificantly (50.9 ng/ml; 95% confidence interval: -51.2-152.9, P = 0.3) higher in comparison to placebo, whereas in men randomized to green tea supplements, IGFBP-3 was nonsignificantly (205.2 ng/ml; 95% confidence interval: -583.3-172.9, P = 0.3) lower than with placebo. In this small, pilot randomized controlled trial, there was little evidence that lycopene or green tea interventions influenced serum levels of IGF-I, IGF-II, IGFBBP-3 and IGFBP-2. However, the effects were imprecisely estimates and some observed trends may justify larger trials.
通过随机试验，可以使用癌症风险或进展的中间生物标志物来评估前列腺癌（PCa）是否可以通过饮食干预来预防。我们研究了番茄红素或绿茶是否可以改变处于 PCa 高风险的男性的循环胰岛素样生长因子（IGF）肽。在英国范围内的前列腺癌检测和治疗试验（ProtecT）中，参与者（年龄在 50-69 岁之间），前列腺特异性抗原（PSA）在 2.0 至 2.95ng/ml 之间或活检呈阴性，随机分为每天服用番茄红素（44 人分配 15mg 胶囊/天；44 人分配富含番茄红素的饮食；45 人分配安慰剂）和绿茶（45 人分配 600mg/天表没食子儿茶素没食子酸酯；45 人分配绿茶饮料；43 人分配安慰剂），为期 6 个月。干预措施在 6 个月的随访中显著提高了主要结局，即血清表没食子儿茶素没食子酸酯和番茄红素。我们在此报告了一项探索性分析，其中在基线和干预后 6 个月测量了血清 IGF-I、IGF-II、IGF 结合蛋白（BP）-2 和 IGFBP-3。共有 133 名男性被随机分配（34%符合条件的男性被接触），130 名男性进行了随访 IGF 肽（98%）。在意向治疗分析中，只有微弱的证据表明番茄红素或绿茶会影响某些方面的血清 IGF-I、IGF-II、IGFBP-2 或 IGFBP-3。在接受番茄红素补充剂治疗的男性中，IGFBP-2 显著升高（50.9ng/ml；95%置信区间：-51.2-152.9，P=0.3），而在接受绿茶补充剂治疗的男性中，IGFBP-3 显著降低（205.2ng/ml；95%置信区间：-583.3-172.9，P=0.3），低于安慰剂。在这项小型的随机对照试验中，几乎没有证据表明番茄红素或绿茶干预会影响 IGF-I、IGF-II、IGFBBP-3 和 IGFBP-2 的血清水平。然而，这些影响是粗略估计的，一些观察到的趋势可能证明更大规模的试验是合理的。
