I have not read anything negative about flax seed, only positive. I am estrogen positive also, and I use flax seed most days in my oatmeal. Maybe I should ask the oncologist about that.

I phoned my oncologist last week about this topic. His nurse ran it by him and the nutritionist. They said they had no problem with me eating up to 4 tablespoons of ground flax per day. Hope this helps. I am going to keep eating it.

I personally choose to avoid flax seed. I live in BC (British Columbia) and at our Cancer Clinic there is an oncologist dietitian that any patients can see for free. We also have a toll free phone number, dial "811" and you can talk to a dietitian, a pharmacist, or nurse for free. In the flyer they gave me, at the Cancer Clinic, there is a section that is entitled "What natural health products contain hormones?" In the print- out that I received, they mention Flaxseed (not including flaxseed oil) as containing possible hormones. ( This flyer is from an approved list by the BC Cancer Agency, Breast Tumour Group, July 2008). Other things, besides flax seeds that they tell us here to avoid (that may include hormones) are:
African Wild Potato, Aletris, Alfalfa, Androstenedoine, Anise, Asparagus racemosus, Beta-sitosterolds, bitter yam, black cohosh, blue cohosh, Black Currant, Bladderwrack, Boron, Burdock, Chaseteberry, Chrysin, Cola nut, DHEA, Dong Quai, Dyer's Broom, Epimedium, Evening Primrose Oil, Fennel, Flaxseed (not flaxseed oil), Flor Essence (contains red clover) Fo-ti, Genistein, (combined polysaccharide), German chamomile, Ginseng, Guarana, Guggul, Hops, Hu-Zhang, Ipriflavone, Job's tears, Kudzu, Lavender, Licorice, Milk Thistle, Mountain Flax, Oregano, Pana (pseudo ginseng), Pleurisy root, Pomegranate seeds, Pregnenolone, Raspberry leaf, Red Clover, Resveratrol,/ seed extract, Scarlet pimpernet, Sage, Schisandra, Soy supplements, Star Anise, Tea tree oil, Tinospora cordifolia, Wild carrot, Wild Yam.
To sum it up, our Cancer Clinic here is a leading research centre so,... personally, I chose to avoid flax seed. No one knows the answers to why we have breast cancer, but I choose to avoid all alcohol, red meats (except at a summer BBQ), and all herbal types of things. I am no expert, but I do like to read up on things. A good site to read is PubMed. You can type in breast cancer and read all day long! Again, things can change, but my decisions are: if you question something, why do it?
(I am not a medical professional).
P.S. The list they gave me say that these products "may" contain hormones in a variety of doses and formulations. Check the product label carefully as some products may contain a combination of ingredients from that list.
Recommended resources: See Natural Medicines Comprehensive Database at www.naturaldatabase.com. or the book is called The Natural Medicines Comprehensive Database. To order a copy call 1 209 472 2244.

Thanks for that. I'm also triple positive and I try to avoid anything which may alter hormones.

This is all so depressing and confusing at times. I can't keep up with what to avoid and what not to avoid, as it seems to change daily. I am just trying to eat as healthy as I can, though I know I eat too much sugar and consume (probably) too much alcohol. My oncologist gave me advise that I try to follow: live my life. I have read conflicting things about the flax seed. My cholesterol has gone down, and I am pretty sure the flax is why. I am taking tamoxifen, so hopefully that would cancel out any estrogen havoc caused by the flax seed. I trust my oncologist: and I just try not to get all crazy about stuff. I also stopped reading everything on the internet. There is a point when being informed is replaced by being nuts...when I was first diagnosed it drove me nuts to read all that was out there. Now I am just trying to be as healthy as I can be without obsessing. I believe all of the plastics and harmful things in the air are probably more detrimental than some natural flax seed for me.