Abstract: The present invention relates to compositions and methods comprising chemopreventive agents that may be cupredoxin(s) or variants, derivatives and structural equivalents of cupredoxins, and at least one other chemopreventive agent. Specifically, these compositions may comprise azurin from Pseudomonas aeruginosa, and/or the 50-77 residue region of azurin (p28). The at least one other chemopreventive agent may comprise an antiestrogen such as Tamoxifen. The compositions of the invention may be used to prevent the development of premalignant lesions in mammalian cells, tissues and animals, and thus prevent cancer.