Preclinical and clinical studies of interferons and interferon inducers in breast cancer.

Preclinical and clinical studies suggest interferons and interferon inducers have antitumor activity for breast carcinoma. Observations include inhibition of growth of freshly derived and continuously passaged breast carcinoma cells in vitro, decreased tumor size and increased survival in spontaneous mouse mammary carcinoma, inhibition of growth of xenogeneic human breast carcinomas grown in nude mice, and reduction of measurable tumors in women. Since clinical doses and schedules have to date been largely empirically derived, additional studies will be required to define optimal clinical use. Furthermore, not all interferon types or subtypes may prove clinically effective. Therefore, use of interferons or interferon inducers in patients should remain restricted to controlled trials with well-defined research objectives.