Contagious cancer on the New York Times

The always interesting Olivia Judson has a column on the contagious cancer inflicting (and infecting) the Tasmanian devils population (see also this previous post).
While Tasmanian devils are susceptible to such cancer due to the very little genetic variance between individuals, Judson proposes a way for contagious cancer to evolve in humans:

What about us? Humans have lots of MHC diversity. But we have another risk factor. Owing to the failure to treat H.I.V., the virus that causes AIDS, in many parts of the world, large numbers of people have compromised immune systems. This is the sort of environment that could, perhaps, allow a transmissible cancer to evolve. Initially, it would circulate only among those who are immunocompromised. But, over time, it might evolve to infect healthy people too. It’s an alarming thought — though happily, a thought is all it is. For now.

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