This is a link to another article which is clearer but also raises issues...??
http://www.medpagetoday.com/Hematolo...herapy/tb/3789
ABSTRACT
"Women taking tamoxifen are more likely to develop estrogen-receptor (ER) negative tumors, which have a worse prognosis than ER-positive cancers. When that is taken into consideration, Dr. Melnikow and colleagues found, tamoxifen actually appears to reduce survival until the five-year breast cancer risk is at least 2.1%."