The present invention describes the use of angiotensin-(1-7) peptide as an anti-cancer therapeutic. Thus, in one embodiment, the present invention comprises a composition to inhibit the growth of cancer cells in an individual comprising a pharmaceutically effective amount of an agonist for the angiotensin-(1-7) receptor to inhibit cancer cell growth or proliferation. Application of a pharmaceutically effective amount of angiotensin-(1-7) or angiotensin-(1-7) receptor agonist is associated with an increase in the expression of genes involved in tumor suppression, apoptosis, and/or cell cycle inhibition, and a decrease the expression of known oncogenes, protein kinases, and/or cell cycle progression genes. Cancers treated using the methods and compositions described herein include cancers having an angiotensin-(1-7) receptor, including, but not limited to, breast and lung cancer.