In addition to its potent mechanism-dependent inhibition of estrogen biosynthesis, in accordance with the embodiments of the present invention, it has now been found that exemestane has novel chemoprotective properties which have hitherto not been explicitly recognized. The present invention provides methods for the use of compositions comprising exemestane for chemoprotection against a wide variety of non-mammary tumors (and possibly other chronic diseases) that are not estrogen-dependent, but have oxidative stress, inflammation and electrophile-damaging etiologies. The present invention also shows that exemestane shows powerful synergism with other classes of Nrf2-activators and phase 2 enzyme gene activators, including, for example sulforaphane (an isothiocyanate), shikonin (a naphthoquinone), zerumbone (a cyclic sesquiterpene) and resveratrol (a stilbene derivative), which increases the attractiveness of exemestanes novel uses.