Data on comparative rates of cancer in different species are sparse. Boddy et al. analyzed 42 years of necropsy data from the San Diego Zoo for 37 mammalian species and found no relation between malignancy rates and lifespan, body mass or placental invasiveness, but found an association between malignancy rate and litter size. Wagner et al. question the conclusion that rates of malignancy are not related to placental type because Boddy et al. calculate the malignancy rate per necropsy whereas Wagner et al. would prefer the malignancy rate per tumor. Wagner et al. find a relationship between placentation type and malignancy rate using their preferred measure. In their response, Boddy et al. argue that these rates measure different things, and both are useful.

中文翻译：

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评论Boddy等人之间的交流。和Wagner等人：恶性肿瘤，胎盘形成和产仔数

关于不同物种中癌症相对发生率的数据很少。Boddy等。分析了圣地亚哥动物园42种尸体的37种哺乳动物尸体数据，发现恶性肿瘤率与寿命，体重或胎盘侵袭性之间没有关系，但是发现恶性率与窝产仔数之间存在关联。Wagner等。由于Boddy等人的质疑，恶性率与胎盘类型无关的结论。每次尸检的恶性率则由Wagner等计算。倾向于每个肿瘤的恶性率。Wagner等。使用他们的首选测度发现胎盘类型与恶性程度之间的关系。在他们的回应中，Boddy等。认为这些费率衡量的是不同的东西，两者都很有用。