Prognostication in canine anal sac adenocarcinomas (ASACs) is difficult due to conflicting evidence regarding metastatic rates and median survival times (MSTs). The transcription factor signal transducer and activator of transcription 3 (STAT3) is a prognostic predictor in several human cancers. The aim of this retrospective study was to assess STAT3 expression in ASACs and to explore its association with clinical presentation and outcome. We hypothesized that STAT3 expression would distinguish tumours with early versus late metastasis. Records from The Queen's Veterinary School Hospital, Cambridge, UK, were searched for dogs diagnosed with ASAC from 2008 to 2019. Immunohistochemical expression of phosphorylated STAT3 (pSTAT3) was assessed in primary tumours (n = 57) and metastatic lymph nodes (n = 30) and MSTs were calculated for cases with low and high pSTAT3 expression. Of the 57 cases assessed, 27 presented with primary tumours but no metastasis and 30 with both primary and local metastatic disease. Most cases (50/57) expressed nuclear pSTAT3 within neoplastic cells in both primary tumour and metastatic lymph nodes. pSTAT3 expression was predominantly observed in neoplastic cells at the edges of neoplastic lobules, suggesting a potential role in invasion. There was no significant difference in pSTAT3 expression between cases metastatic at presentation and those that did not have detectable metastasis at presentation. There was no significant difference between the MSTs in cases with high and low pSTAT3 expression. Cases that presented with metastatic disease had shorter MSTs (395 days) than those with primary tumours alone (623 days). Although pSTAT3 is variably expressed in primary and metastatic ASAC cells, pSTAT3 did not provide prognostic information for canine ASAC.

由于关于转移率和中位生存时间 (MST) 的证据相互矛盾，犬肛囊腺癌 (ASAC) 的预后很难。转录因子信号转导和转录激活因子 3 (STAT3) 是几种人类癌症的预后预测因子。这项回顾性研究的目的是评估ASACs中STAT3的表达，并探讨其与临床表现和结果的关系。我们假设 STAT3 表达将区分具有早期转移和晚期转移的肿瘤。从英国剑桥女王兽医学校医院的记录中搜索了 2008 年至 2019 年被诊断出患有 ASC 的狗。在原发性肿瘤（n = 57）和转移性淋巴结（n = 30）中评估磷酸化 STAT3 (pSTAT3) 的免疫组织化学表达，并针对具有低和高 pSTAT3 表达的病例计算 MST。在评估的 57 例病例中，27 例有原发肿瘤但没有转移，30 例有原发灶和局部转移病灶。大多数病例 (50/57) 在原发肿瘤和转移淋巴结的肿瘤细胞内表达核 pSTAT3。pSTAT3 表达主要在肿瘤小叶边缘的肿瘤细胞中观察到，表明在侵袭中具有潜在作用。就诊时发生转移的病例与就诊时未检测到转移的病例之间的 pSTAT3 表达没有显着差异。在具有高和低 pSTAT3 表达的情况下，MST 之间没有显着差异。出现转移性疾病的病例的 MST（395 天）比单纯原发肿瘤的病例（623 天）短。尽管 pSTAT3 在原发和转移性 ASAC 细胞中表达不同，但 pSTAT3 并未提供犬 ASAC 的预后信息。