A smart acquisition strategy has made Bristol-Meyers, which has bought seven companies since October 2007, a big player in the cancer-treatment industry. Its purchase of Medarex in July added a key drug for metastic melanoma that’s in Phase III trials. The drug has possible multiple indications – industry jargon for its ability to treat more than one condition – for lung and prostate cancer.But BMY also sells Erbitux for colorectal, head and neck cancer, Ixempra for breast cancer, Taxol for breawatch now