 Until this time, the treatment for this type of breast cancer was oophorectomy.Jordan returned to Leeds University as a Lecturer in Pharmacology between 1974 and 1979, after which he spent one year at Ludwig Institute for Cancer Research at the University of Bern, Switzerland.In 1980, Jordan joined the University of Wisconsin–Madison where he started to look at the effects of tamoxifen and another SERM, raloxifene, on bone density and coronary systems.