That's right, we develop the disease!...and if we develop the disease then there has got to be a way to not develop the disease!  Today we know that there are ways to at least decrease our risk of breast cancer.

Our environment is full of xenoestrogens that are affecting both sexes. 
As women, we consume birth control pills and take hormone replacement unabated.  The press and scientists keep telling us of one study that indicates hormones to blame for the rise in breast cancer and then the next news release doubts the validity of the published finding.

If we all have lived long enough, we know not to believe what we hear and believe only half of what we read.  So what do we do to protect ourselves?
Some easy steps are to decrease the amounts of xenoestrogens we place in our bodies...that is minimize or eliminate pesticide use...eat organic as much as possible, especially dairy...minimize drugs that contain hormones and eat lots of cruciferous vegetables.  We need to realize that even if we "do all the right things," we can still have trouble with our own bodily hormones because we may metabolize them along the wrong pathway....or we may have bacteria in our GI tract that will recycle the estrogens!!  I'll explain more later.

Today, due to scientific investigations, we realize that there are FOODS that help us metabolize these xenoestrogens and normal estrogens. 
The elder President Bush did nothing for the lowly broccoli except leave more for me!...because it seems that it is the sulfur bearing compounds in these cruciferous vegetables that up regulate a liver enzyme CYP1A2.

One study (2) found that 500mg [about 1 pound] of broccoli every 12 days improved the 2-OH-estrone (E1) to 16-alpha-E1 ratios and up regulated the liver enzyme CYP1A2.

Indol-3-Carbinol
Since our culture is into "fast-everything," scientists initially found that I3C [Indol-3-Carbinol] was the active ingredient in the cruciferous vegetables.  It seems that I3C induced 2-hydroxylation of estrone and improved the 2/16-alpha-E1 ratio.
A recent scientific article (3) showed that I3C caused a complete regression of cervical CIN II-III dysplasia in 50% of the participants and definitely improved the 2/16 ratio in dosages ranging from 2-400mg/day.  [I have been using this fact in my treatment of abnormal pap smears for a long time.]
This action of I3C seems to be due to the down regulation of CYPB1B, which metabolizes E1 to the carcinogen 4-OH-E1. 

Diindolylmethane
Since the absorption of I3C is limited and causes GI upset at high doses [remember the gas you can get with cabbage!!!], the scientist have isolated the most active metabolite in I3C called DIM [Diindolylmethane].
DIM has been shown to induce a favorable 2/16-alpha-estrone ratio and induce apoptosis [cellular suicide] in breast cancer cells. (4&5)
Most common dosing is 60mg DIM twice a day for women and 90-120mg/day for men.

Phytoestrogens
Soy isoflavones and flax lignans have demonstrated the ability to decrease 17-beta-estradiol (E2) levels and increase 2-OH estrone levels.(6) They also have shown to improve 2/16 ratio and additionally to decrease levels of 4-OH-E1 and 4-OH-E2, which are potentially carcinogenic.(7)

Calcium D-glucarate
Calcium D-glucarate (CDG) aids the body in inhibiting beta-glucuronidase, an enzyme produced by gut flora that removes the glucuronidase portion off of carcinogens, tumor promoters or hormones. Once the beta-glucuronidase is removed, the carcinogens can then be reabsorbed back into our bodies instead of being dumped out of our gut when we have a bowel movement.
Calcium D-glucarate then indirectly supports the elimination system of potential tumor promoters by making sure they do not disengage from their transport system out of the body.  This then eases the burden of the liver.(8) 

Conclusion
So, life style adaptations along with ingestion of either I3C or DIM and CDG seems to make the most logical mode-of-action for the scientific data base we now possess. 

References
1. Bernard Roswit and herbert Edlis. "Carcinoma of the Male Breast: A Thirty Year Experience and Literature Review. Current Concepts in Cancer." Radiation Oncology Biology Physics 4:711-716, 1978.

2. Cancer Letter 1997 Mar 19; 114 (1-2): 169-170).

3. Gynecology Oncology 2000 Aug; 78(2): 123-9.

4. Biochem Pharmacology 1999 Sep1; 58(5):825-34.

5. Carcinogenesis 1998 Sep; 19(9):1631-9.

6. Cancer Research 2000 Mar 1;60(5):1299-305.

7. Cancer Epidemiology Biomarkers Prevention 1998 Dec;7 (12): 1101-8.

8. Cancer Detect Prev 1997; 21(2):178-90.