[Sally Anne]

Japanese girls' have much smaller boobs then western girls, this means the phytoestrogens in their diets is not high enough to grow their boobs bigger, so it is definitely not enough to increase their chance to get breast cancer.

No, indeed not. In fact the higher the amount of phytoestrogens in the diet of any country the less the rate of breast cancer.

Also, studies of Japanese women who live in the USA show that once Japanese women consume a typical Western diet the rate of breast cancer rises to the usual Western level.