Dr. Pike’s research interests are in the etiology and chemoprevention of breast, endometrial and ovarian cancer. A woman’s risks of endometrial cancer and of ovarian cancer are significantly and importantly reduced by use of oral contraceptives (OCs). The protection increases with increasing duration of OC use and lasts for more than 30 years after the last use of OCs. Why OC use protects against endometrial cancer is well-understood, but why OC use protects against ovarian cancer is not. Understanding the mechanism of prevention is important in order to guide research into how to increase the protective effect. For example, until recently almost all OC packs contained 21 active and 7 placebo pills, but recently a number of OCs have been marketed increasing the ratio of active to placebo pills to 24:4 and 84:7. If ovarian cancer risk reduction is determined through ovulation inhibition these changes will have little effect on the extent of risk reduction. If, however, the protection is through increased exposure to the progestin component of the OC then these changes could make the protection much greater. Dr. Pike is working with gynecologic faculty at Memorial Sloan Kettering on understanding the mechanism of protection against ovarian cancer from OCs by studying the biology of the fallopian tube and cortical inclusion cysts within the ovary, the two sites where current evidence suggests most ovarian cancers arise. Dr. Pike is also working with radiology faculty at Memorial Sloan Kettering to evaluate whether the various forms of breast magnetic resonance imaging (MRI) can be used to identify women at greatly increased risk of breast cancer and to study the ‘activity’ of the breast as an aid to various studies of possible approaches to prevention of breast cancer, including changes in OC formulation.