Cohorts with Unique Exposures
Follow-up Study of Women with Augmentation Mammoplasty
The long-term health effects of augmentation mammoplasty remain unclear. In terms of cancer risk, there is concern both about breast cancer risk, due to the interference of implants in allowing mammographic visualization of lesions, as well as about other cancers, whose risk may be altered because of immunologic or other host responses to a foreign body. Following a congressional mandate, a retrospective cohort study was undertaken in collaboration with 18 plastic surgery practices. Assembled for study were 13,500 women having undergone augmentation mammoplasty at these practices prior to 1989 and 4,000 comparison patients (women receiving other types of plastic surgery). Results have been published regarding the effects on cancer risk and with mortality. Additional results regarding relationships of implants to connective tissue disorders are forthcoming. More information, Louise Brinton.
Follow-up Study of Women Evaluated and Treated for Infertility
Infertility has long been recognized as altering risks of a variety of cancers, including breast and gynecologic cancers. More recently, concern has arisen regarding effects of certain drugs used to treat infertility on the risk of ovarian cancer. This concern is based on the fact that many of these drugs stimulate ovulation and that a major etiologic hypothesis regarding ovarian cancer relates to the frequency of ovulation ("incessant ovulation" hypothesis). Although several epidemiologic studies have found some evidence for an increased risk of ovarian cancer associated with use of these drugs, the relationship is far from conclusive. To further address this issue, a retrospective cohort study was conducted in collaboration with four large reproductive endocrinology practices where women have been evaluated and/or treated for infertility. Included were approximately 12,000 women seen at these practices prior to 1989. Detailed information was abstracted from medical records, and located patients were administered questionnaires to obtain updated information regarding disease risk factors and health status. Results regarding effects of ovulation-stimulating drugs on ovarian cancer (recently published) were reassuring in not showing overall association. Slight but non-significant increases in risk among the women followed for the longest periods of time, however, suggest the need for further monitoring of effects. Results regarding effects of infertility drugs on other cancers and of the effects of specific causes of infertility in relation to cancer risk will also be considered in future publications. More information, Louise Brinton.
Follow-Up Study of Women in the Fracture Intervention Trial (FIT)
Bone density has emerged as a potentially important predictor of risk for certain cancers that are influenced by hormones, such as breast and endometrial cancers. In 1992, over 25,000 postmenopausal women volunteered for FIT, which was a clinical trial to determine whether the drug alendronate could reduce the incidence of osteoporosis fractures. A retrospective cohort study using data from FIT will be used to evaluate how bone mineral density of the hip is related to subsequent cancer risk. National Cancer Institute and FIT investigators will contact all FIT volunteers to identify incident cancers, and to evaluate whether risk factor information collected in 1992, such as measured bone mineral density, lifestyle factors, and certain growth factors, predicts subsequent cancer risk. Collection of additional risk factor information during this follow-up, including updated lifestyle factors and buccal cells for genetic analyses, will allow investigators to further explore the complex relationships between bone mass and other suspected risk factors for breast, endometrial, and other cancers. More information, James Lacey.
Health Status of Children Conceived After Use of Ovulation Stimulating Drugs
Although a number of studies have focused on the health status of women exposed to various infertility medications, little attention has been given to how these drugs might affect offspring of successful pregnancies. A collaboration was undertaken with investigators at the Danish Cancer Registry to assess the health status of children born to approximately 45,000 women previously evaluated and treated for infertility. This project was facilitated by capabilities for linkage of different registries, including the Danish National Hospital Discharge Registry, the National Birth Registry and the Danish Cancer Registry. The results showed no overall association of childhood cancers associated with maternal use of fertility drugs. The only indication of any elevation in risk of a specific cancer was for cancers occurring later in life (especially childhood hematopoietic malignancies), which may have related to underlying reasons for medication usage. More information, Louise Brinton.
Gynecologic Operations Record Linkage Project in Denmark
This collaborative project was designed to study the risk of cancer among women who had previously undergone gynecologic surgery. Through linkage with the Danish National Patient Discharge Register and the Danish cancer Registry, approximately 90,000 eligible women were identified and followed prospectively for cancer occurrence. A total of 3,200 women were identified with cancer. Additional information including age, age at operation, and indications for surgery was also collected. This data set is currently being used to test hypotheses related to risks of breast and ovarian cancers among women who have had a previous hysterectomy and/or oophorectomy. More information, Louise Brinton.
