Hum, so I wonder then if a man was taking allergy shots regularly for Wasp and Bee stings if it would be a preventive vaccine for Prostate Cancer as well? The shots have venom in them. Prostate Cancer finally claimed my dad about four years ago but I have taken allergy shots on a regular basis for stings for 10 years now so in case I get stung I won't have as a severe of a reaction.
The other thing is, that what you're allergic to might have nothing to do with this toxin. This is a very specific toxin produced by a very specific wasp. Most "venom" is actually a complex mixture of a number of different toxins, binders, and other supporting chemicals anyway, so even if you were getting immunotherapy for this particular wasp, that wouldn't mean you were allergic to, or targeting relief from, this particular component.
I'm sure I don't need to tell you that if you've got a history of prostate cancer in your family it's better to rely on regular PSA + digital exams than to think you're protected by wasp antigens at this early point in the research...