How Small Was the Estrogen Progesterone Breast Cancer Rise?

On the show, the relative risk increase of breast cancer in the estrogen plus synthetic progesterone group versus placebo was 25 to 27 percent. The only headline said HRT increases risk of breast cancer by 27 percent. The absolute risk increase was 0.1 percent, a difference between five cases per thousand and four cases per thousand, one case in a thousand. The breast cancer headline turned out not to be true.

Preliminary results were first made available before peer review and before publication, and a huge press announcement said women receiving CEE plus MPA in the group with a uterus had a higher incidence of breast cancer. Going from four in a thousand to five in a thousand is a 25 percent increase, and stating the relative change alone is a completely inappropriate context. A relative risk change is never to be given without an absolute risk beside it.

Headlines of that sort are nothing short of criminal because they distort people's thinking and steer the course of science and medicine for decades.