the reason it is so hard to determine if flax oil or lignans are good/bad for bc

[Lani]

1) testing on cell lines, not people
2) cell line may not reflect an individual person's cancer type (MCF7 is ER+PR+ her2- and much less agressive than her2 and driven by other pathways)
3) a little causes increase in ER, a lot decreases it--how do we know how much is a little and a lot (and the effect of the timing of the dosages and of the persons' unique metabolism of the active ingredient)
4) there are many kinds of estrogen receptor besides alpha and beta
5) the tumor may be influenced by ER levels in surrounding and distant tissues and not just those in the cancer cells themselves
6) there may be negative feedback mechanisms at play
7) patients are not going to volunteer for, nor insurance companies pay for repeated neoadjuvant biopsies of patients taking different doses of lignans on different schedules,

among others...now with that caveat emptor,...

Anticancer Res. 2010 May;30(5):1695-9.
Effects of Phytoestrogen Extracts Isolated from Flax on Estradiol Production and ER/PR Expression in MCF7 Breast Cancer Cells.
Richter DU, Abarzua S, Chrobak M, Scholz C, Kuhn C, Schulze S, Kupka MS, Friese K, Briese V, Piechulla B, Jeschke U.

Ludwig-Maximilians-University of Munich, Department of Obstetrics and Gynaecology, Maistrasse 11, D-80337 Munich, Germany. udo.jeschke@med.uni-muenchen.de.
Abstract
BACKGROUND: In this study, we tested the effects of crude extracts from flax (Linum usitatissimum) on the production of estradiol and expression of estrogen receptor (ER) and progesterone receptor (PR) in human breast cancer MCF7 cells. MATERIALS AND METHODS: Isoflavone and lignan extracts from flax plant Linum usitatissimum were obtained, using different extraction methods. Breast carcinoma cells (MCF7) were incubated with various concentrations of the isolated extracts. Untreated MCF7 cells were used as controls. Supernatants were removed at designated times and tested for estradiol with an ELISA method. Furthermore, the effect of phytoestrogen extracts on the production of ERa and ERbeta as well as on PR was examined. Results and CONCLUSION: Production of estradiol is elevated in MCF7 cells in a concentration-dependent manner after stimulation with isoflavone and lignan extracts from Linum usitatissimum. Expression of ERalpha is up-regulated after stimulation with lower concentrations of lignan extracts from flax plants, unchanged at median concentrations and down-regulated at high concentrations. Expression of ERbeta is down-regulated in a concentration-dependent manner.

PMID: 20592363 [

[Jackie07]

Very good comment, Lani.

I have just recently started (remember) to add flax seed powder in my breakfast oatmeal (having purchased the big jar more than a year ago.) If anything, it's a good fiber source. I definitely want to prevent colo-rectal cancer since my 2nd Brother has been treated for colon cancer.

[1rarebird]

So, they found alpha-ER was up regulated and beta-ER could go up or down depending on how much flax lignan and isoflavone was administered. With these results we still don't have enough to hazard a guess whether to supplement with flax or not.

I suppose the oncologist that I heard speak on phytoestrogens a few months ago was correct when advising ER+ patients on endocrine therapy to avoid flax until more is known. She felt it could help or hurt, and on the chance it would hurt, it was not worth the risk . She advised that Tamoxifen or and the A'Is should be allowed to work unhindered by flax. Too bad for me---I enjoyed my flax and granola until I heard her rationale.

bird