Schott Courtney R, Tatiersky Laetitia J, Foster Robert A, Wood Geoffrey A
1 Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
Vet Pathol. 2018 Mar;55(2):202-211. doi: 10.1177/0300985817747329. Epub 2017 Dec 28.
Canine appendicular osteosarcoma is an aggressive bone neoplasm that imposes a short survival time. There are several published histologic grading systems for canine osteosarcoma but no universally accepted system. Location within the skeleton and therapy received are both correlated with survival time, but these factors were not always considered when the prognostic value of published grading systems was determined. Our objective was to compare 2 published histologic grading systems in a population of dogs with appendicular osteosarcoma treated with the standard of care for curative intent. Three evaluators graded 85 tumors using 2 histologic grading systems. The relationships between histologic grade as well as individual histologic features and outcome (survival time and disease-free interval) were evaluated using Kaplan-Meier survival functions and a univariate Cox proportional hazards model. Histologic grade, as assigned by any evaluator, did not correlate with outcome. Increased number of mitotic figures per 3 randomly selected 400× microscope fields, as assessed by 1 evaluator, was correlated with both survival time and disease-free interval; this was the only individual histologic feature that was significantly correlated with outcome for any evaluator. These findings cast doubt on the predictive value of routine histologic grading in dogs with appendicular osteosarcoma who receive amputation followed by adjuvant chemotherapy and highlight the need for better tools to predict outcome in canine appendicular osteosarcoma.
犬附肢骨肉瘤是一种侵袭性骨肿瘤，生存时间较短。目前已有几种已发表的犬骨肉瘤组织学分级系统，但尚无普遍接受的系统。骨骼部位和接受的治疗均与生存时间相关，但在确定已发表分级系统的预后价值时，这些因素并非总是被考虑在内。我们的目的是在一群接受根治性标准治疗的附肢骨肉瘤犬中比较两种已发表的组织学分级系统。三名评估者使用两种组织学分级系统对85个肿瘤进行了分级。使用Kaplan-Meier生存函数和单变量Cox比例风险模型评估组织学分级以及个体组织学特征与预后（生存时间和无病间期）之间的关系。任何评估者指定的组织学分级均与预后无关。一名评估者评估发现，每3个随机选择的400倍显微镜视野中，有丝分裂象数量增加与生存时间和无病间期均相关；这是任何评估者发现的唯一与预后显著相关的个体组织学特征。这些发现对接受截肢及辅助化疗的附肢骨肉瘤犬常规组织学分级的预测价值提出了质疑，并强调需要更好的工具来预测犬附肢骨肉瘤的预后。
