Asao T, Nakamura J, Shitara Y, Tsutsumi S, Mochiki E, Shimura T, Takenoshita S, Kuwano H
Department of Surgery I, Gunma University School of Medicine, Maebashi, Japan.
Dis Colon Rectum. 2000 Sep;43(9):1250-4; discussion 1254-5. doi: 10.1007/BF02237430.
Recent advances have made possible the treatment of small invasive colorectal cancer by means of polypectomy or endoscopic mucosal resection. CD44 expression in cancer cells was identified as an indicator of lymph-node metastasis, which could be evaluated in specimens removed by colonoscopy.
The correlation between lymph-node metastasis and the expression of standard-type CD44 in cancer cells was examined immunohistologically using the invaded cancer cells of 61 tissue samples of superficially invasive colorectal cancer. We defined the above as invasive cancer restricted within the colorectal wall. Of the 61 samples, 31 had submucosal invasion and 30 had muscular invasion.
Standard-type CD44 expression in the area of invasion in cases with lymph-node metastasis was remarkably down-regulated. In 43 cases with no lymph-node metastasis, 36 (83.7 percent) of patients had CD44 expression in invaded cells, whereas only two of 18 cases (11.1 percent) with lymph-node metastasis had expression of standard-type CD44 in the same area (P < 0.0001). A total of 69.6 percent (16/23) of patients with loss of standard-type CD44 expression in invaded sites were found to have positive metastasis in the lymph nodes. These results suggest that standard-type CD44 in invasive colon cancer cells could suppress metastasis to the regional lymph nodes.
In cases of invasive colorectal cancer, the loss of standard-type CD44 expression in the invaded area is a sensitive marker for metastasis to the lymph nodes. Further investigation with larger patient groups is required to clarify the reliability of loss of standard-type CD44 expression as an indicator for additional surgery after endoscopic resection of submucosal invasive colorectal carcinoma.
近年来的进展使得通过息肉切除术或内镜黏膜切除术治疗小的浸润性结直肠癌成为可能。癌细胞中的CD44表达被确定为淋巴结转移的一个指标，这可以在通过结肠镜切除的标本中进行评估。
使用61例浅表浸润性结直肠癌组织样本的浸润癌细胞，通过免疫组织化学方法检测淋巴结转移与癌细胞中标准型CD44表达之间的相关性。我们将上述情况定义为局限于结直肠壁内的浸润性癌。在这61个样本中，31例有黏膜下层浸润，30例有肌层浸润。
有淋巴结转移的病例中，浸润区域的标准型CD44表达明显下调。在43例无淋巴结转移的病例中，36例（83.7%）患者的浸润细胞中有CD44表达，而在18例有淋巴结转移的病例中，只有2例（11.1%）在同一区域有标准型CD44表达（P<0.0001）。在浸润部位标准型CD44表达缺失的患者中，共有69.6%（16/23）被发现淋巴结有阳性转移。这些结果表明，浸润性结肠癌细胞中的标准型CD44可能抑制向区域淋巴结的转移。
在浸润性结直肠癌病例中，浸润区域标准型CD44表达缺失是淋巴结转移的一个敏感标志物。需要对更大的患者群体进行进一步研究，以阐明标准型CD44表达缺失作为内镜切除黏膜下浸润性结直肠癌后是否需要额外手术的指标的可靠性。
