CTS and anastrazole
27 March 2013 - 9:38am
I am on adjuvant hormone treatment for Ca Breast and changed to anastrazole last July after 2 awful years on Tamoxifen. Ceveloped CTS symptons about a month ago in L hand which is side where I had lymph node dissection. No evidence of lymphodema . Read the info on the website (which as a GP as well as patient I found extremely helpful ) of the link with anastrazole (and it is mentioned in the side effects on the patient leaflet in some brands of the drug but not others) and wondered whether CTS is more likely to develop on the affected side or is it just coincidence. Do we know why aromatase inhibitors due cause CTS?
I suspect that the balance of oestrogen/progestogen has an influence on the biochemistry of the connective tissue in the carpal tunnel which acts to increase microvascular exudation and local fibrosis and neovascularisation - some interesting biochemical studies are referenced in the site but the whole story does not quite hang together yet. I still need time to do some more extensive reading on effects of sex hormones outside the reproductive system amongst other things.
The first affected side is usually determined by handedness with the dominant hand usually being first but in some patients there is an obvious cause for CTS to present in a particular hand, such as a Colles fracture. Assuming you are right handed then one would have to wonder if some subtle impairment of lymphatic drainage might be adding to the risk of CTS on that side even though it might not be enough to cause overt lymphoedema.
Do you come across many patients with CTS? - I once met a GP from Cheshire who told me that he had never seen a case. JB