Karmanos Cancer Institute, Wayne State University, Detroit, Michigan, USA.
Nutr Cancer. 2010;62(7):996-1000. doi: 10.1080/01635581.2010.509839.
Soy isoflavones sensitize prostate cancer cells to radiation therapy by inhibiting cell survival pathways activated by radiation. At the same time, soy isoflavones have significant antioxidant and anti-inflammatory activity, which may help prevent the side effects of radiation. Therefore, we hypothesized that soy isoflavones could be useful when given in conjunction with curative radiation therapy in patients with localized prostate cancer. In addition to enhancing the efficacy of radiation therapy, soy isoflavones could prevent the adverse effects of radiation. We conducted a pilot study to investigate the effects of soy isoflavone supplementation on acute and subacute toxicity (≤6 mo) of external beam radiation therapy in patients with localized prostate cancer. Forty-two patients with prostate cancer were randomly assigned to receive 200 mg soy isoflavone (Group 1) or placebo (Group 2) daily for 6 mo beginning with the first day of radiation therapy, which was administered in 1.8 to 2.5 Gy fractions for a total of 73.8 to 77.5 Gy. Adverse effects of radiation therapy on bladder, bowel, and sexual function were assessed by a self-administered quality of life questionnaire at 3 and 6 mo. Only 26 and 27 patients returned completed questionnaires at 3 and 6 mo, respectively. At each time point, urinary, bowel, and sexual adverse symptoms induced by radiation therapy were decreased in the soy isoflavone group compared to placebo group. At 3 mo, soy-treated patients had less urinary incontinence, less urgency, and better erectile function as compared to the placebo group. At 6 mo, the symptoms in soy-treated patients were further improved as compared to the placebo group. These patients had less dripping/leakage of urine (7.7% in Group 1 vs. 28.4% in Group 2), less rectal cramping/diarrhea (7.7% vs. 21.4%), and less pain with bowel movements (0% vs. 14.8%) than placebo-treated patients. There was also a higher overall ability to have erections (77% vs. 57.1%). The results suggest that soy isoflavones taken in conjunction with radiation therapy could reduce the urinary, intestinal, and sexual adverse effects in patients with prostate cancer.
大豆异黄酮通过抑制辐射激活的细胞存活途径使前列腺癌细胞对放射治疗敏感。同时，大豆异黄酮具有显著的抗氧化和抗炎活性，这可能有助于预防辐射的副作用。因此，我们假设大豆异黄酮与局部前列腺癌患者的根治性放射治疗联合使用可能会有所帮助。除了增强放射治疗的疗效外，大豆异黄酮还可以预防辐射的不良反应。我们进行了一项初步研究，以调查大豆异黄酮补充剂对局部前列腺癌患者接受外照射放射治疗的急性和亚急性毒性（≤6 个月）的影响。42 名前列腺癌患者被随机分配每天接受 200 毫克大豆异黄酮（第 1 组）或安慰剂（第 2 组），从放射治疗的第一天开始，每天给予 1.8 至 2.5Gy 分剂量，共给予 73.8 至 77.5Gy。通过自我管理的生活质量问卷在 3 个月和 6 个月时评估放射治疗对膀胱、肠道和性功能的影响。只有 26 名和 27 名患者分别在 3 个月和 6 个月时返回完整的问卷。在每个时间点，与安慰剂组相比，大豆异黄酮组放射治疗引起的尿路、肠道和性功能不良症状均减少。在 3 个月时，与安慰剂组相比，大豆治疗组患者的尿失禁、尿急和勃起功能更好。在 6 个月时，与安慰剂组相比，大豆治疗组患者的症状进一步改善。这些患者的尿液滴漏/泄漏（第 1 组为 7.7%，第 2 组为 28.4%）、直肠痉挛/腹泻（7.7%比 21.4%）和排便时疼痛（0%比 14.8%）均少于安慰剂治疗组。勃起的总体能力也更高（77%比 57.1%）。结果表明，大豆异黄酮与放射治疗联合使用可降低前列腺癌患者的尿路、肠道和性功能不良影响。
