Cancer research is an expensive and fiercely competitive business. As with all scientific research, in cancer research the questions you ask will limit the kinds of answers you can get. In addition, your perception of any problem can be affected by the way you express or display your answers. For example, incidence of breast cancer is decreasing among women younger than 50 but increasing among women older than 50. So if you average women of all ages, you mask the effect in older women, allowing you to claim that the breast cancer picture doesn't look so bad.
Japanese women living in Japan have about one-quarter as much breast cancer as American women.
Then during the decade 1976-1986, the death rate from breast cancer dropped sharply among Israeli women 44 or younger while the death rate among older Israeli women continued to rise. Improved therapy does not seem to account for the improved death rate among young Israeli women. Then in 1978 a crescendo of public protest brought a ban, and thus rapid reduction in all these contaminants. The scientists who studied pesticides and breast cancer in Israel made the important observation that all known factors contributing to breast cancer affect the hormone estrogen. Yet so far the cancer establishment expresses contempt for such ideas because they have not adopted a prevention philosophy.