From your post it sounds as though both of your lumpectomies were for DCIS? Tamoxifen is usually recommended for pre-menopausal women with oestrogen positive invasive ductal carcinoma and other oestrogen positive breast cancer. I'm not sure about DCIS and imagine this may be where the difference of opinion comes from re your surgeon and your oncologist, perhaps the surgeon being belt and braces and the oncologist more focused on weighing up any benefits v side effects/quality of life?
On reading your post I think it may be worth you giving the Breast Cancer Now nurse a ring, with a bit more detail about your lumps and diagnosis or contact your breast care nurse at the hospital and see if they can shed any light on the approach re DCIS and Tamoxifen, since it sounds like it might be worth getting more clarity. Clearly its on your mind for you to have posted. Are you due to have any follow up appointments with either your surgeon or oncologist soon? If so you could discuss it then?
I just wondered if anyone else has been given advice that Tamoxifen will be of little benefit to them?
I decided in May, not to take it following this advice of my oncologist that the benefits of 'reducing an already small risk' vs side effects.
My background is a DCIS diagnosis, 2 lumpectomies and a course of radiotherapy. My surgeon had always said that I would need Tamoxifen, but this advice changed when I was referred to the oncologist for radiotherapy.