View clinical trials related to Breast Cancer.
Filter by:This study will examine long-term health effects of cosmetic breast augmentation (enlargement) with silicone gel breast implants. There has been concern for some time about the possible effects of breast implants on the immune system particularly regarding the development of certain connective tissue disorders and on the possibility that implants may interfere with the ability to detect breast cancers. More recently, concerns have been raised regarding the possible cancer-causing effect of the implants themselves. These concerns were heightened by reports that the polyurethane foam coating that envelops the silicone gel in some implants may dissolve and produce a chemical called 2,4,-diamino toluene (TDA), which has been linked to an increased risk of breast and other cancers in rats and mice. To address this issue, this study will gather information from the medical records and a questionnaire survey of approximately 12,000 breast implant patients. The questionnaire will request information on perceived complications of the implants; history of breast examinations and mammograms; frequency of breast self examination; development of diseases (particularly cancers and connective tissue disorders) developed subsequent to the augmentation surgery; potential risk factors for these diseases, such as age at menarche (onset of menstruation), age at first birth, age and type of menopause (natural or due to surgery); history of breast biopsies; immune system and connective tissue disorders; cigarette smoking; alcohol consumption; family medical history, and so forth. To evaluate the results, the information will be compared with the same data on 4,000 women who underwent other plastic surgery procedures, such as rhinoplasty, facelift, liposuction, dermabrasion, eyelifts, and others, from the same practices as the breast augmentation patients. Participants will be recruited for the study from several large reconstructive and plastic surgery practices. Among the breast implant patients, women who have had bilateral breast implants for cosmetic purposes only, and not as breast reconstruction after breast cancer surgery, will be eligible. Women with a history of breast cancer may not participate.
To assess the relations of infertility causes and treatment to cancer risk, we will conduct a retrospective cohort study of approximately 12,000 women evaluated for infertility between 1965-1988. These women will be ascertained from several large infertility clinics and private practices in various geographic locations in the United States: Boston, Chicago, Detroit, New York, and Palo Alto. These practices were selected on the basis of their having large number of patients who received ovulation stimulating drugs many years in the distant past. Abstractors reviewed clinic medical records to identify eligible study participants and abstract data needed to classify causes of infertility and document therapies employed. Using a variety of tracing sources (including the National Death Index, credit bureaus, and postmasters), the vital status and location of the study subjects were determined. Subjects who were traced and identified as alive are being sent a detailed questionnaire that requests information on their health status as well as on a number of lifestyle practices. For subjects who report a cancer, medical verification is being sought from the diagnosing physicians and/or facilities. Death certificates are being sought for deceased subjects.
Flight attendants may be at an increased risk of breast and other cancers due to work-place exposures including cosmic radiation and circadian rhythm disruption form traveling across multiple time zones. This cancer incidence study will determine whether female flight attendants are at increased risk of breast and other cancers and whether the risk is dose-related. The study will include a cohort of approximately 10,000 women who were employed as flight attendants for one or more years. Breast cancer cases will be identified from telephone interviews of living subjects and next-of-kin of deceased subjects, as well as from death certificates. The interview will also provide information about non-occupational risk factors for breast cancer such as parity. Both internal and external comparisons will be made. The primary analysis will evaluate the risk associated with occupational exposure within the cohort, controlling for non-occupational risk factors by stratification or modeling. The secondary analysis will compare the incidence of breast cancer in the cohort to that in the general population, with adjustment for factors such as lower parity which might increase breast cancer risk in the cohort independent of occupational exposure to cosmic radiation and circadian rhythm disruption. The risk of other ionizing radiation-related cancers, such as leukemia, lung cancer, and thyroid cancer, among flight attendants will also be evaluated. The results of the study will apply to female flight crew and frequent fliers.
This study will examine DNA from cancer patients previously treated with Gleevec to look for a variation (mutation) of the ABCG2 gene that may render the drug less effective in certain patients. Gleevec is used to treat chronic myeloid leukemia and gastrointestinal tumors. Although most patients respond to treatment, many with advanced disease develop resistance to the drug. It is thought that in some patients this resistance results from the action of a protein that causes Gleevec to be pumped out of the cells, reducing its usefulness. Patients enrolled in clinical trials of Gleevec at the National Cancer Institute and at other participating institutions are eligible for this study. DNA from patients' blood samples are analyzed for the ABCG2 gene and correlated with clinical data, such as the patient's age, race, disease state, weight, height, and body surface area. It will also look at the drug dose, how often the drug is given, the duration of treatment, side effects and other medications taken.
A prospective cohort study is proposed to evaluate occupational and environmental risk factors for cancer among women in Shanghai, China. Approximately 75,000 women aged 40-69 who reside in eight geographically defined communities in two urban districts of Shanghai will be recruited via a community-based cancer education program. All eligible subjects will be invited by local health workers from the neighborhood health station to the clinic for an interview and selected anthropometric measurements. The interview will elicit information on demographic background, diet, lifestyle factors, medical history, lifetime occupational history and residential history for the past 20 years. In addition, the women will be asked for information on their husbands' current and usual occupations, and demographic and a few other exposure factors. A spot urine sample and 10 ml of blood will be collected from all cohort members and stored at -70 degrees C for future assays of urine metabolites and DNA and hemoglobin adducts of selected occupational and environmental carcinogens, and polymorphic genes encoding enzymes that are involved in metabolism of relevant carcinogens. Cohort members and their husbands will be followed for cancer outcomes through biennial recontact and linkage with files of the population-based Shanghai Cancer Registry, of the Shanghai Vital Statistics, and of the Shanghai Resident Registry. Medical records and pathology slides will be reviewed for all cancer cases to verify their diagnosis. Post-diagnostic blood samples will be obtained from all cohort members diagnosed with cancer during the follow-up period and stored for future methodologic and etiologic studies. The proposed initial study period is 5 years, with an average follow-up of about 3.5 years. We anticipate, however, that follow-up will continue for 10 years or more.
This study is a retrospective one, exploring the hypothesis that a person's genotypic makeup may be associated with a clinical response or toxic effect to a drug. Genetic polymorphisms, that is, states of being able to assume different forms, that are in drug-metabolizing enzymes, transporters, and receptors may affect a patient's response to drug therapy. To date, there have been limited studies looking at a drug-metabolizing genotype (genetic makeup) or phenotype (result of the genotype's interaction with the environment). However, it is often wondered if the variations in a drug's action, that is, pharmacokinetic effect, come from the genotype phenotype relationship. Participants who entered previous clinical trials at the National Cancer Institute, as approved by the Central Institutional Review Board, may be eligible for this study. Studies for which pharmacokinetic analyses were or are being performed will be the source of the patient population. Genotyping experiments will be performed through genomic DNA isolated from stored frozen serum. The genotyping results will be compared with pharmacokinetic data and clinical outcomes. Clinical data will consist of what is obtained during the course of the principal pharmacokinetic study. The results of the retrospective analyses will provide no direct benefit to the participants.
This study will collect information on the height and weight of women who participated in a 1998 study in Triana, Alabama, on the risk of breast cancer and benign breast disease in relation to environmental exposure to the pesticide DDT and similar chemicals. This additional information is needed to calculate the participants' body mass index (BMI), which is required for completing analysis of the data. The 1998 study-a collaborative effort of the National Cancer Institute, the Triana Area Medical Fund, and the College of Nursing at the University of Alabama at Huntsville-investigated possible effects of DDT and other compounds on the risk of breast cancer, predominantly among African-American women in the area of Triana, Alabama. The study was initiated as a result of medical findings showing high blood levels of DDT among the local population who had consumed fish from a tributary of the Tennessee River that had been polluted by the discharge over several decades of large quantities of pesticides from a DDT production plant. Women participating in the study had a mammogram, physical examination, breast examination, and blood draw, and completed a questionnaire on diet and lifestyle factors. In order to complete analysis of the data and determine whether there is an association between environmental exposure to DDT and related chemicals and breast cancer risk, additional information on BMI is required.
This study will continue to analyze data collected by the Women's Contraceptive and Reproductive Experiences (CARE) study. The CARE study was designed to evaluate the association between reproductive factors and risk of breast cancer in white and African-American women in the United States. The present study is not recruiting additional participants. The original study enrolled 4,575 women with breast cancer and 4,682 control subjects between 35 and 64 years of age All participants provided a blood sample for genetic study. The samples were analyzed for variants (mutations) in the BRCA1 and BRCA2 genes, the vitamin D receptor gene, the androgen receptor gene, and the insulin-like growth factor-1 gene. In addition, all participants were interviewed to obtain information related to breast cancer risk, including a history of reproductive, menstrual, oral contraceptive, and hormone replacement therapy use; lifestyle factors such as smoking, alcohol use, body weight, and physical activity; history of medical conditions and procedures; demographic characteristics, such as age, race, marital status, and so forth; and a detailed family history of cancer.
Diethylstilbestrol (DES), a drug first synthesized in 1938, was administered to several million pregnant women in the U.S. and Europe for the prevention of spontaneous abortion and premature delivery. In 1971, Herbst reported a strong association between DES use in pregnancy and the occurrence of vaginal clear cell adenocarcinoma (CCA) in exposed female offspring. Animal models have demonstrated a range of DES effects on offspring exposed in utero, including reproductive dysfunction, immune system changes, behavioral and sexual abnormalities, and increases in various reproductive cancers in males and females. In the mid-1970's, several separate cohorts of DES-exposed daughters and unexposed comparison groups were followed for the occurrence of cancer, precursor lesions, and reproductive effects, but systematic follow-up of these cohorts had ceased by 1990. In 1992, Congress passed a bill (H;.R. 4178) mandating the continued follow-up of DES-exposed cohorts. The National Cancer Institute, in collaboration with five field centers, reassembled previously studied cohorts of DES-exposed and unexposed mothers, daughters and sons, and identified subjects with documented exposure status who had not been studied previously, through familial links within the cohorts. Standardized baseline questionnaires were mailed to cohort members to ascertain the risk of cancer and other disorders. Pathology reports were collected for reported cancers and preneoplastic conditions. Two separate rounds of follow up have been conducted and a third is almost complete. Patients from the Registry for Research on Hormonal Transplacental Carcinogenesis (the Registry) will be added to the follow-up effort in the third phase. The purpose of this study is to continue the follow-up, by means of mail questionnaires and medical record collection, which was begun during the first phase of the study. Concern has arisen that DES-exposed daughters may be at higher risk of breast cancer. Exposure to high levels of endogenous estrogen in utero has been hypothesized to increase the risk of breast cancer and DES is a potent estrogen. Cancer risk in the sons will also continue to be assessed, especially for increased risks of prostate cancer. Since the offspring who were exposed to DES in utero are currently reaching their late forties, when cancer rates begin to rise, it is important to continue the follow-up of these cohorts to determine if there are long-term increases in cancer risk.
Recent cohort studies demonstrated reduced breast cancer risks among women with a history of fractures or low bone mineral density (BMD). In the Study of Osteoporotic Fractures, each standard deviation increase in distal radius BMD was associated with a 50% increased risk over three years of follow-up, while in the Framingham study, women in the highest quartile of metacarpal bone mass had a 3.5-fold higher risk than women in the lowest quartile. The impact of the severity and timing of bone loss on risk has not yet been investigated, and the extent to which other risk factors (family history, anthropometric factors, physical activity, and exogenous hormones) modify the relationship with BMD is unknown. To elaborate on these research questions, we are conducting a follow-up study of 22,695 postmenopausal women who volunteered for the Fracture Intervention Trial (FIT), a trial of the bone-enhancing drug alendronate. This large cohort includes extensive baseline information on major breast cancer risk factors, and thus is ideal for evaluating potential interactions with BMD and the effects of BMD on other cancer sites. Endometrial cancer has been reported to occur more frequently among women with a history of fracture, but no previous studies have specifically investigated its relationship to BMD. We are investigating whether BMD of the proximal femur predicts breast cancer risk; whether breast cancer risk factors among postmenopausal women modify the relationship with BMD; whether BMD predicts endometrial or other cancers; and whether measurable biomarkers offer further etiologic clues about BMD and cancer risk. We have contacted the surviving members of FIT to ascertain incident cancers. Risk factors and fracture history are being updated through a self-administered questionnaire. To supplement the serum samples collected at baseline, we are using a nested case-control study approach to collect buccal cell specimens, which may be useful for measuring a variety of biomarkers, including endogenous hormones and genetic polymorphisms involved in either bone growth (e.g., vitamin D receptor) or hormone metabolism (e.g., CYP17, COMT). Retrieval of operative and pathology reports is being used to validate self-reported cancers. The social security numbers and contacts names provided by FIT participants when they completed the baseline questionnaire are facilitating comprehensive follow-up and a National Death Index search for those who cannot be located. The baseline data, the established cooperation of this study population, and the collection of additional biospecimens should enable this study to answer important questions about BMD in breast and endometrial cancers.