Yes, vaccine induced sarcomas have been known to develop in some cats. But they aren't too common, especially if your cat hasn't had years and years of shots in the same location.
I think these days, though, veterinarians are being careful about it and giving shots to the cats in different locations. Some clinics have also come up with a combo shot, so instead of the poor kitty getting jabbed 3 times, it's all in one shot. So, I think your sundance will be just fine Is this an indoor only kitty or an indoor/outdoor kitty? We'll be thinking about your babe

Don't let what I'm going to say next scare you!! By all means, I think my cat just had a reaction to a shot he's had before, which baffled me...but I wanted to get some opionions about it...

Catwoman, thanks for the points about the shots for indoor cats. I did have a very bad experience last time I took my Marius for shots. He must have had some horrible reaction to the shot (it was the Fel Leuk and the upper res shots...he's on 3 year rabies, so he didn't get that one this time, and hasn't ever had problems with shots before), and he got very sick and was vomiting blood. The vet wasn't concerned about it and said it was just a reaction due to the injection that was given in his smooth muscle (the vet gave the shot in his side this time). I was debating whether or not to even take him for shots again after that occurance. My 2 babies are indoor only, so the rabies would really be all they would need, huh? Should I avoid the Fel Leuk next time? What about the upper res? Aside from that, none of my animals have ever had any problems with shots...and they're just fine, lazy, lovable housecats!