Siegers C P, von Hertzberg-Lottin E, Otte M, Schneider B
Institute of Toxicology, Medical University of Lubeck, Germany.
Gut. 1993 Aug;34(8):1099-101. doi: 10.1136/gut.34.8.1099.
Anthranoid-containing laxatives--aloe, cascara, frangula, and rheum--may play a role in colorectal cancer. This risk is particularly important in view of the wide abuse of self administered laxatives for chronic constipation. There are data on the genotoxic potential of anthranoids and there is evidence of a tumourigenic potential in rodents. A case report and clinical-epidemiological studies have evaluated the cancer risk in patients who have abused anthranoid laxatives over a long period. Pseudomelanosis coli is a reliable parameter of chronic laxative abuse (> 9-12 months) and is specific for anthranoid drugs. In a retrospective study of 3049 patients who underwent diagnostic colorectal endoscopy the incidence of pseudomelanosis coli was 3.13% in patients without pathological changes. In those with colorectal adenomas, the incidence increased to 8.64% (p < 0.01), and in those with colorectal carcinomas it was 3.29%. This lower rate was probably caused by incomplete documentation of pseudomelanosis coli in those with carcinoma. In a prospective study of 1095 patients, the incidence of pseudomelanosis coli was 6.9% for patients with no abnormality seen on endoscopy, 9.8% (p = 0.068) for patients with adenomas, and 18.6% for patients with colorectal carcinomas. From these data a relative risk of 3.04 (1.18, 4.90; 95% confidence interval) can be calculated for colorectal cancer as a result of anthranoid laxative abuse.
含蒽类的泻药——芦荟、鼠李皮、欧鼠李和大黄——可能在结直肠癌中起作用。鉴于慢性便秘患者广泛滥用自行服用的泻药，这种风险尤为重要。有关于蒽类遗传毒性潜力的数据，并且有证据表明在啮齿动物中有致癌潜力。一项病例报告和临床流行病学研究评估了长期滥用蒽类泻药患者的癌症风险。结肠黑变病是慢性泻药滥用（>9 - 12个月）的可靠指标，且对蒽类药物具有特异性。在一项对3049例接受诊断性结直肠内镜检查患者的回顾性研究中，无病理改变患者的结肠黑变病发生率为3.13%。在患有结肠腺瘤的患者中，发生率增至8.64%（p < 0.01），而在患有结直肠癌的患者中为3.29%。这一较低的发生率可能是由于癌症患者中结肠黑变病记录不完整所致。在一项对1095例患者的前瞻性研究中，内镜检查未见异常的患者结肠黑变病发生率为6.9%，患有腺瘤的患者为9.8%（p = 0.068），患有结直肠癌的患者为18.6%。根据这些数据，可以计算出因滥用蒽类泻药导致结直肠癌的相对风险为3.04（1.18，4.90；95%置信区间）。
