I don’t know where you originally got Rupert from, whether it was a breeder or someone you know, or a rescue that had a litter, but I would stay away from that main source.
If given the opportunity, I would not adopt a rabbit from the same person I got Wick from. Wick has a slew of medical abnormalities, and they all stem from having poor conditions/environment. I would be shocked of his other litter mates are healthy (no way of knowing, but they probably all have syphilis and began with a URI like him)
Now genetics can be different than environmental factors (though as you know environmental factors can trigger genetically dormant characteristics), but that being said, it can be a sign of poor breeding, if that is indeed the case for Rupert. As you mention though, it was a very rare form of cancer.
There are plenty of rabbits outside Rupert’s family who’d love a caring owner, and I think any rabbit would be grateful for your love.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.