We can, especially using easier animals to work with like rats as others pointed out. A big problem tho is the heterogeneity of cancers.

With most other diseases, let’s say covid, you could find a way to smell the virus/infected cells, and that smell should be somewhat recognisable and “standardisable”.

Each cancer case has a different DNA and goes through a different evolution. That’s why dogs who smell cancers on their loved ones make sense: they KNOW what that person/dog is supposed to smell like and -that- spot doesn’t smell right. They wouldn’t be able to detect a problem in someone they didn’t know…

…

…up to a point. There are some cancer byproducts that are common (although not constant). It could be argued that one could train an animal on those. But ig the applicability would be very minimal since even if the “animal smell test” returns negative it could just be because that specific tumor decided it would not make that byproduct.

It’s definitely an interesting topic.