Our hypothesis is that silent molecular lesions, defined as molecular alterations
detectable in histologically normal endometrial, ovarian, and tubal tissues, represent markers of cancer risk. Incessant ovulation represents one of the most widely-recognized models to explain the pathogenesis of ovarian cancer, with women who have had a high number of lifetime ovulatory menstrual cycles being at increased cancer risk because of repeated ovulation-related injury to, and repair of, ovarian surface epithelium (OSE). This extremely delicate single layer of cells exfoliates easily on handling, with the majority of cells typically being lost in routine handling, when collected post-operatively. Furthermore, the identification of early stage ovarian cancer is uncommon, and the vast majority of ovarian cancers are not associated with recognizable precursors. The lack of effective techniques for collecting and studying OSE in the laboratory represents a major barrier to molecular studies designed to uncover the etiology and early pathogenesis of ovarian cancer. This proposal will develop a collection method for OSE, and demonstrate its utility for various molecular analyses. Recent evidence suggests that a subset of ovarian cancers may originate in the fallopian tubes. Therefore, we will pilot the collection of cells from the fallopian tubes. If successful, the collection of OSE and fallopian tube cells will provide the basis for larger studies aimed at identifying early molecular events in ovarian carcinogenesis.
In this pilot, we will collect endometrial and ovarian tissues (that would otherwise have been discarded without histopathologic examination) from 125 hysterectomy and/or unilateral or bilateral oophorectomy specimens obtained from women ages 18 and older who were operated on for benign indications. As an amendment to this active protocol, we propose demonstrating the feasibility of obtaining intra-operative cytobrushings of ovarian surface epithelial cells on 50 women to be accrued onto the study, which will include women having hysterectomy (or unilateral oophorectomy) alone without removal of the ovaries at the time of surgery. Furthermore, we will extend the collection to cells from the fallopian tubes in 225 women for a total population of 400.
We will administer a questionnaire assessing endometrial and ovarian cancer risk factors and gynecologic history; obtain blood and urine; and obtain carefully-mapped frozen and fixed endometrial and ovarian tissues. We will immunostain endometrial tissues to assess the presence, number, location, and size of foci containing PTEN-null glands, which represents a validated surrogate of mutations in the PTEN tumor suppressor gene. This pilot will demonstrate the feasibility of executing this complex protocol; determine the number and spacing of sections required to accurately and efficiently assess the PTEN status of the endometrium; and provide data for developing power estimates needed to propose a full-scale study with a sufficient number of subjects to test our hypothesis that PTEN abnormalities account for a substantial proportion of the risk associated with recognized epidemiologic endometrial cancer risk factors. It will assess the feasibility of performing molecular analyses on ovarian surface epithelial cells and tubal cells collected intra-operatively, and correlating molecular findings with known ovarian cancer risk factors. If successful, this will provide the basis for larger studies aimed at identifying early molecular events in
ovarian carcinogenesis, particularly in the setting of women at increased genetic
risk of ovarian cancer. The pilot itself will also provide an extremely valuable
repository for future biomarker pilot studies.
