I personally think that transition along with top and bottom surgery saved my life. My mother had similar concerns, and I am older than you are. I went ahead with surgery because *I* needed it. And shortly thereafter my mother and both of my sisters were diagnosed with cancer in all of those parts (breast for mom, ovarian for one sister, and uterine for another). Prior to this there had not been any cancer in my family.
My personal opinion is that if you do not need those parts, then get rid of them ASAP (read: as finances/insurance allows). I know some people prefer to keep them, and that's fine. But if you don't care, or want them gone, get rid of them. I, for one, am thrilled they are gone. I was happiest when I awoke from my total hysto surgery. Much happier than even getting my penis I'd been praying for since I was 4 years old. The parts that were the bane of my existence gone was the thrill of a lifetime.
Just my personal opinion. I am not a doctor nor do I play one on the internet.
Jay
PS Yes, what others say is true; as long as you are on hormone replacement therapy you shouldn't have issues with osteoporosis and the like.