Melatonin-depleted blood spurs tumor growth
In late 1987, Richard G. Stevens, then at Pacific Northwest Laboratories in Richland, Wash., typed up a short letter and mailed it to Walter Willett at Harvard Medical School in Boston. The two epidemiologists had met just once, and Stevens wasn't confident that his 209-word note, or the suggestion that it contained about a possible contributor to breast cancer, would inspire any action.
But Willett took the suggestion seriously. He and his colleagues began a study that only they could do. They run the Nurses' Health Study, a project unrivaled in scope and duration that tracks how w