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 associations of implants on risk of cancer and connective tissue disorders and on mortality More information, Louise Brinton.
Follow-up Study of Women Evaluated and Treated for Infertility
Infertility has long been recognized as a risk factor for various cancers, including breast and gynecologic cancers. More recently, concern has been raised regarding effects of drugs used to treat infertility, particularly since these drugs stimulate ovulation and raise endogenous estrogen levels. We assembled a retrospective cohort study in collaboration with four large reproductive endocrinology practices where women have been evaluated and/or treated for infertility. Included were 12,193 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 (through 1998) regarding disease risk factors and health status. Linkages were also performed with eight cancer registries and the National Death Index. Results regarding effects of ovulation-stimulating drugs on ovarian and breast cancer were largely reassuring, although there were slight but non-significant increases in risk among the women followed for the longest periods of time. Nearly two-fold increases in risk of uterine cancers were seen among women treated for long periods of time with clomiphene, of interest given that this is a selective estrogen receptor modulator with chemical properties similar to tamoxifen, another drug extensively linked with this cancer. In our previous follow-up, the cohort was relatively young. We have therefore recently initiated another round of follow-up, which will provide another 10 years of follow-up and considerably greater power to evaluate effects not only for the cancers previously evaluated but also for other cancers that might be affected by hormonal exposures (e.g., melanoma and thyroid cancers).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, Louise Brinton.
