Erlotinib attacks a part of cancer cells that helps them live and grow. Studies done in human beings show that this drug can make a difference in the way anti-estrogens work in hormone-sensitive breast cancers. OSI-906 attacks a different part of the cancer cell that helps them live and grow. Studies done in the laboratory show that OSI-906 can make a difference in the way anti-estrogens work in hormone-sensitive breast cancers.