Munday John S, Brennan Moira M, Jaber Azhar M, Kiupel Matti
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
Comp Med. 2006 Apr;56(2):136-41.
Approximately 7% of old, unthrifty sheep (Ovis aries) in New Zealand have intestinal adenocarcinomas. To investigate whether these sheep might be used as a model of human colonic neoplasia, the biologic behavior and histologic appearance of ovine intestinal adenocarcinomas were compared with those reported for human colonic adenocarcinomas. We collected 50 intestinal tracts with grossly visible intestinal neoplasia from slaughtered sheep. Neoplasms were assessed using World Health Organization guidelines for assessment of human colonic adenocarcinomas. All ovine adenocarcinomas developed in the small intestine. In contrast, only 4% of human intestinal tumors develop at this location, whereas the majority develop in the colon. A visible polyp is present within 89% of human colonic adenocarcinomas, whereas polyps were present in only 46% of the ovine neoplasms. Intestinal wall infiltration by the neoplastic cells and rates of lymph node (84% in sheep; 61% in humans) and distant (52% in sheep; 17% in humans) metastases were comparable between ovine and human adenocarcinomas. However, ovine adenocarcinomas developed more peritoneal and fewer hepatic metastases than human adenocarcinomas. Histologic grading of ovine tumors revealed cell differentiation similar to that reported within human colonic adenocarcinomas. In conclusion, ovine intestinal adenocarcinomas, like human colonic adenocarcinomas, typically arise spontaneously and consistently develop widespread metastases. In addition, tumors appear histologically similar between these species. Therefore, sheep may provide a model of advanced human colonic cancer, possibly allowing evaluation of novel therapeutics and surgical procedures.
在新西兰，约7%的老龄、不节俭的绵羊（Ovis aries）患有肠道腺癌。为了研究这些绵羊是否可作为人类结肠肿瘤的模型，将绵羊肠道腺癌的生物学行为和组织学表现与已报道的人类结肠腺癌进行了比较。我们从屠宰的绵羊中收集了50个有肉眼可见肠道肿瘤的肠道。使用世界卫生组织评估人类结肠腺癌的指南对肿瘤进行评估。所有绵羊腺癌均发生在小肠。相比之下，人类肠道肿瘤只有4%发生在这个部位，而大多数发生在结肠。89%的人类结肠腺癌中有可见息肉，而绵羊肿瘤中只有46%有息肉。肿瘤细胞对肠壁的浸润以及淋巴结转移率（绵羊为84%；人类为61%）和远处转移率（绵羊为52%；人类为17%）在绵羊和人类腺癌之间具有可比性。然而，绵羊腺癌发生的腹膜转移比人类腺癌多，肝转移比人类腺癌少。绵羊肿瘤的组织学分级显示细胞分化与人类结肠腺癌中报道的相似。总之，绵羊肠道腺癌与人类结肠腺癌一样，通常自发产生并持续发生广泛转移。此外，这些物种的肿瘤在组织学上看起来相似。因此，绵羊可能提供一种晚期人类结肠癌模型，可能有助于评估新的治疗方法和手术程序。
