Did your pharmacist say what type(s) of cancer he felt you were at a higher risk of because you're not replacing the hormones? I have a couple of thoughts about that.
First, depending on your personal and family medical history, your risk of colon cancer might be greater than your risk of breast or gyn cancers; and estrogen replacement does lower our risk of colon cancer.
Second... even if he was referring to breast and gyn cancers, he might have something there. See, it's not "estrogen" that causes breast cancer, for example (I'll pick on that one because I'm most familiar with it and because you've had everything else removed so your risks there are quite low now)... there are lots of substances that can be carcinogenic, and one particular form of estrone called 16 alpha hydroxy estrone is among them. If you were replacing the estrogen your ovaries used to make, you could potentially use a very low dose of estradiol to relieve your symptoms and protect the health of your bones and colon, and your body would produce very little 16 alpha hydroxy estrone compared to the amount it might make without using estrogen replacement simply due to increased production of estrones in your abdominal fat cells as your body tries to compensate for the loss of the ovaries. (Of course, taking oral estrogen, which requires a much higher (20x) dosage, could expose you to more 16 alpha hydroxy estrone.) And, it is possible to alter the way your body metabolizes estrogens to steer the pathway away from the 16 alpha hydroxy estrone and towards 2 hydroxyestrone (a "good" estrone) through the use of dietary indoles such as diindolylmethane (DIM), which is available OTC. There are links available in our Resources directory, in the Breast Health section, which explain this in detail.
Now, about your symptoms (or lack thereof)... effexor is sometimes prescribed for hot flashes, which may be why you're not having very many. However, there are lots of hidden conditions that result from low estrogen levels that take a while to surface. One is osteoporosis. Have you had a baseline DEXA scan yet? It's a quick, easy, non invasive test which measures your bone density. I have had one every other year since my hyst. The first one, done at a time when I had been trying hard to wean down to a very low dose of estrogen, showed I had borderline osteopenia. The second one, two years later, after I'd raised my dosage to a better level for me, showed an increase in bone density
JMHO here, of course, but... I would be inclined to work with bio-identical estrogen replacement to deal with the anxiety (I also had that problem on low estrogen, and it went away when I raised the dose) -- you might just find you don't need the effexor at all. My inclination to do that is because I figure that the anxiety may be caused by an estrogen deficiency, but I'm pretty sure it's not
caused by an effexor deficiency
Ultimately, it's your body, and you'll need to decide what you feel is right for you. Remember that if you decide to try HRT, it's not an irreversible decision. Nothing is cast in stone here. Why not check out some of the links in Resources, talk with the pharmacist again to clarify what he meant, and then talk with your DR about what you think of all this?