Devil facial tumour disease (DFTD) is caused by a transmissible cancer (devil facial tumour 1 [DFT1]) and is unique to the Tasmanian devil (Sarcophilus harrisii).
It emerged as an important disease of free-ranging Tasmanian devils on the east coast of Tas. in early 2001. Subsequently, wider studies revealed that the cancer was present in a significant proportion of the population and was spreading (Hawkins et al.
2006). DFTD may have been present as early as 1996. Photographs of Tasmanian devils with consistent gross lesions were taken in north-eastern Tas. and a histological review of tissue from a case submitted to the Animal Health Laboratories of the Department of Primary Industries, Parks, Water and Environment (DPIPWE), Tas. in 1997 revealed changes morphologically consistent with what subsequently became defined as DFTD (Loh et al. 2006a; Loh et al. 2006b). McCallum et al. (2007) predicted the possible extinction of free-ranging Tasmanian devils from the effects of this disease within 20 yr of its emergence. Since its emergence, much research effort has been directed at understanding the cancer, its pathogenesis and effects on free-ranging populations and significant progress has been made in our understanding of this unique transmissible cancer (Pyecroft et al. 2007; Holz 2008; Jones and McCallum 2011; Deakin and Belov 2012; Bender et al. 2014; Grueber et al. 2015; Pye et al. 2016c; Stammnitz et al. 2023).The concept of a cancer transferring between hosts as a viable entity is counterintuitive as our understanding of oncology and immunity progresses. Nonetheless, there are several naturally occurring transmissible cancers that have been described in a range of species. The first of notoriety was canine transmissible venereal tumour (CTVT) in domestic dogs (Canis familiaris), a clonal cell line arising ~10 000-12 000 yr ago (Belov 2012) and remaining significant today. Fatal leukaemic-like cancers have been reported in at least 15 different bivalve mollusc species (Metzger and Goff 2016). The mechanisms of these cell transfers are still under investigation, but may lend insight as to the mechanism of transmissible clonal neoplasia in higher animals.
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