Nusko G, Schneider B, Ernst H, Wittekind C, Hahn E G
Dept. of Medicine I, University of Erlangen.
Z Gastroenterol. 1997 May;35(5):313-8.
Melanosis coli has long been considered as a harmless pigmentation of the colorectum associated with the use of laxatives containing anthraquinone. Recent experimental and clinical studies, however, have provided some evidence of a possible association between melanosis coli/laxative use and colorectal cancer.
In 2.229 consecutive patients we retrospectively analyzed the association of melanosis coli and laxative use with colorectal neoplasia. All the patients had undergone total colonoscopy, and the colorectal neoplasias had been examined histopathologically in accordance with the WHO classification. Information concerning laxative use, bowel habits and family history of colorectal cancer was obtained from the medical records. The statistical analysis was done using the Mantel-Haenszel-test for linear association.
The presence of colorectal cancer was not associated with melanosis coli or laxative use. However, colorectal adenomas were found significantly more frequently in patients with melanosis coli than in those without melanosis (p = 0.0002). But adenomas associated with melanosis coli were significantly smaller than those not associated with melanosis (p < 0.0001), and were located predominantly in the proximal colon (p = 0.0002). In the patients with melanosis coli the relative risk was significantly higher for tubular (1.80; 95% CI: 1.26-2.56) and tubulovillous adenomas (2.03; 95% CI: 1.09-3.76), but not for villous adenomas. No significant differences were found in the grade of dysplasia of adenomas in patients with, and those without, melanosis coli.
There appears to be no association between colorectal cancer and melanosis coli or laxative use. Colorectal adenomas are more frequently found in patients with melanosis coli. Colorectal adenomas do not contain the melanin-like pigmentation. The association of adenomas with melanosis coli can be explained by the ease of detection of even tiny polyps as white spots within a dark-colored colonic mucosa.
结肠黑变病长期以来一直被认为是与使用含蒽醌类泻药相关的一种无害的结肠色素沉着。然而，最近的实验和临床研究提供了一些证据，表明结肠黑变病/泻药使用与结直肠癌之间可能存在关联。
在2229例连续患者中，我们回顾性分析了结肠黑变病和泻药使用与结直肠肿瘤形成之间的关联。所有患者均接受了全结肠镜检查，结直肠肿瘤均按照世界卫生组织分类进行了组织病理学检查。从病历中获取了有关泻药使用、排便习惯和结直肠癌家族史的信息。使用Mantel-Haenszel线性关联检验进行统计分析。
结直肠癌的存在与结肠黑变病或泻药使用无关。然而，结肠黑变病患者中结直肠腺瘤的发现频率明显高于无结肠黑变病的患者（p = 0.0002）。但与结肠黑变病相关的腺瘤明显小于与黑变病无关的腺瘤（p < 0.0001），且主要位于近端结肠（p = 0.0002）。在结肠黑变病患者中，管状腺瘤（1.80；95%可信区间：1.26 - 2.56）和管状绒毛状腺瘤（2.03；95%可信区间：1.09 - 3.76）的相对风险显著更高，但绒毛状腺瘤并非如此。结肠黑变病患者和无结肠黑变病患者的腺瘤发育异常程度无显著差异。
结直肠癌与结肠黑变病或泻药使用之间似乎没有关联。结肠黑变病患者中结直肠腺瘤更为常见。结直肠腺瘤不含有类似黑色素的色素沉着。腺瘤与结肠黑变病的关联可以通过在深色结肠黏膜内更容易将即使是微小的息肉检测为白色斑点来解释。
