THIS IS NOT FROM A MEDICAL RESOURCE BUT IS INCLUDED AS INFO ONLY

Saved From Alternative Cancer Cures
http://www.datadepo.com/cancercure/cleanses.htm
Restrictive Clothing Research has shown that restrictive clothing can cut off proper circulation of blood and lymph, and thereby participate in the onset of cancer or other diseases. This is especially true of women's brassieres.

You can read Singer and Grismaijer's book Dressed to Kill: The Link Between Breast Cancer and Bras (ISBN Group, 1995) for full details about the studies. They showed that women who wear a bra more than 12 hours a day have a dramatic likelyhood of developing Fibrocystic breast disease.

Sidney Ross Singer and Soma Grismaijer's Site
Books Site

Links:
http://www.all-natural.com/fibrocys.html
Prevent and Treat Fibrocystic Breast Disease

You can visit for a bibliography. Dr. Gregory Heigh of Florida found that over 90% of women with fibrocystic diseases improve their condition when they stop wearing their brassieres. Without a bra, the breasts move with each step. This action tends to flush toxins from the breast areas through the lymph system. Large concentrations of lymph nodes lie just under and in the armpit, and some bras so severely restrict lymph action that trouble can result. Women who exercise have less chance of getting breast cancer. But the likelihood of getting breast cancer is increased by wearing a bra to bed.

The good doctor also asserts that wearing a bra can make the breasts sag even more than they otherwise would because the bra prevents the chest muscles from getting the proper exercise, and so they tend to atrophy, causing more droop. Many women feel that they need to wear a bra in order to be socially acceptable or to elevate sagging breasts so as to be more appealing to men and challenging (or competitive) to other women. While these might seem to be good justifications, they nevertheless increase the risk of breast cancer
For your information, here are the statistics shown in the book: