Biomedical subjects

Barbara Weber

Publications and source records attributed to Barbara Weber.

At least 19 recordsLinked to original sources

PubMed2005

Effect of pregnancy as a risk factor for breast cancer in BRCA1/BRCA2 mutation carriers.

Early age at first birth and multiparity have been associated with a decrease in the risk of breast cancer in women in the general population. We examined whether this relationship is also present in women at high risk of breast cancer due to the presence of a mutation in either of the 2 breast cancer susceptibility genes, BRCA1 or BRCA2. We performed a matched case-control study of 1,260 pairs of women with known BRCA1 or BRCA2 mutations, recruited from North America, Europe and Israel. Women who had been diagnosed with breast cancer were matched with unaffected control subjects for year of birth, country of residence, and mutation (BRCA1 or BRCA2). Study subjects completed a questionnaire detailing their reproductive histories. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. Among BRCA1 carriers, parity per se was not associated with the risk of breast cancer (OR for parous vs. nulliparous = 0.94; 95% CI = 0.75-1.19; p = 0.62). However, women with a BRCA1 mutation and 4 or more children had a 38% decrease in breast cancer risk compared to nulliparous women (OR = 0.62; 95% CI = 0.41-0.94). In contrast, among BRCA2 carriers, increasing parity was associated with an increased risk of breast cancer; women with 2 or more children were at approximately 1.5 times the risk of breast cancer as nulliparous women (OR = 1.53; 95% CI = 1.01-2.32; p = 0.05). Among women with BRCA2 mutations and who were younger than age 50, the (adjusted) risk of breast cancer increased by 17% with each additional birth (OR = 1.17; 95% CI = 1.01-1.36; p = 0.03). There was no significant increase in the risk of breast cancer among BRCA2 carriers older than 50 (OR for each additional birth = 0.97; 95% CI = 0.58-1.53; p = 0.92). In the 2-year period following a birth, the risk of breast cancer in a BRCA2 carrier was increased by 70% compared to nulliparous controls (OR = 1.70; 95% CI = 0.97-3.0). There was a much smaller increase in breast cancer risk among BRCA2 carriers whose last birth was 5 or more years in the past (OR = 1.24; 95% CI = 0.79-1.95). A modest reduction in risk of breast cancer was observed among BRCA1 carriers with 4 or more births. Among BRCA2 carriers, increasing parity was associated with a significant increase in the risk of breast cancer before age 50 and this increase was greatest in the 2-year period following a pregnancy.

Adolescent↗

PubMed2005

The risk of ovarian cancer after breast cancer in BRCA1 and BRCA2 carriers.

OBJECTIVE: To estimate the risk of ovarian cancer after a primary diagnosis of breast cancer among women with a BRCA1 or BRCA2 mutation and to identify host and treatment-related factors that might modify the risk. PATIENTS AND METHODS: Patients were 491 women with stage I or stage II breast cancer, diagnosed from 1975 to 2000 and for whom a BRCA1 or BRCA2 mutation had been identified. Patients were followed from the initial diagnosis of breast cancer until either ovarian cancer, prophylactic oophorectomy, death, or 2002. The medical treatment records and pathology documents were reviewed. Information that was abstracted from the medical charts included date of breast cancer diagnosis, stage of disease, use of chemotherapy, use of radiation therapy, usage of tamoxifen, oophorectomy, recurrence, second malignancy, and vital status. RESULTS: The 10-year actuarial risk of ovarian cancer after breast cancer was 12.7% for BRCA1 carriers and 6.8% for BRCA2 carriers (P = 0.03). The use of tamoxifen (OR = 1.79; P = 0.16) and chemotherapy (OR = 0.59; P = 0.15) did not significantly impact on the risk of subsequent ovarian cancer. Twenty-five percent of the deaths in women with stage I breast cancer were due to a subsequent ovarian cancer. CONCLUSIONS: The high incidence of ovarian cancer suggests that oophorectomy should be recommended in female BRCA1 and BRCA2 mutation carriers with a diagnosis of breast cancer, especially those with stage I disease. Breast cancer systemic therapy did not significantly alter the risk of ovarian cancer.

Adult↗

PubMed2005

About the origin and development of hereditary conventional renal cell carcinoma in a four-generation t(3;8)(p14.1;q24.23) family.

Conventional renal cell carcinoma (CRCC) may appear in families with germline translocations involving chromosome 3, although a recurrent responsible gene has not been found. We recently described a family with CRCC and a constitutional t(3;8)(p14.1;q24.23), and we demonstrated that no genes were disrupted by the translocation breakpoints. In order to investigate the genetic origin and features of the CRCC tumors that occurred in this family, we have extended the pedigree up to four generations, and analyzed peripheral blood samples from 36 members, CRCC tumors, normal renal tissues, and a gastric tumor. (1) By means of comparative genomic hybridization (CGH), we have detected loss of the derivative chromosome carrying 3p in all CRCC but not in the corresponding normal renal tissue. In addition, by means of the fluorescence in situ hybridization technique, we have observed that not all tumoral cells lose the der(3p), which suggests that, previous to this loss, another hit should occur to initiate the transformation of normal into tumoral cells. (2) All known mechanisms of inactivation of the candidate von Hippel-Lindau (VHL) gene have been studied in the tumors, detecting alterations in 65% of them. This confirms that inactivation of the VHL gene is not always required to develop CRCC, and that (an)other suppressor gene(s) on 3p could be involved. (3) We discard FHIT as an alternative pathway to VHL. We have not found new candidate regions along 3p by using a 1-Mb resolution array-based CGH. (4) The tumorigenesis mechanism of a second gastric tumor developed in the probandus is different from that of CRCC.

Acid Anhydride Hydrolases↗

PubMed2004

Smoking and the risk of breast cancer among carriers of BRCA mutations.

The effect of cigarette smoking on the risk of breast cancer is controversial, although most studies show little or no effect. It has been suggested that smoking may reduce the risk of developing hereditary breast cancer. We completed a case-control study on 1,097 women with breast cancer who were BRCA1 or BRCA2 mutation carriers and 1,097 age-matched controls with a mutation in the same gene but without breast cancer. There were no statistically significant differences between the cases and controls in terms of the number of current and ex-smokers (41.2% and 40.4%, respectively) or the age at smoking commencement (18.2 years and 18.5 years, respectively). There were no statistically significant differences between cases and controls regarding beginning smoking within 5 years of menarche (OR = 1.03; 95% CI 0.83 to l.28) or before the first pregnancy (OR = 1.09; 95% CI = 0.90 to 1.33). In conclusion, contrary to our previous report, smoking does not appear to be a risk factor for breast cancer among carriers of BRCA mutations.

Adolescent↗

PubMed2004

Contralateral breast cancer in BRCA1 and BRCA2 mutation carriers.

PURPOSE: To estimate the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers after diagnosis and to determine which factors are predictive of the risk of a second primary breast cancer. PATIENTS AND METHODS: Patients included 491 women with stage I or stage II breast cancer, for whom a BRCA1 or BRCA2 mutation had been identified in the family. Patients were followed from the initial diagnosis of cancer until contralateral mastectomy, contralateral breast cancer, death, or last follow-up. RESULTS: The actuarial risk of contralateral breast cancer was 29.5% at 10 years. Factors that were predictive of a reduced risk were the presence of a BRCA2 mutation (v BRCA1 mutation; hazard ratio [HR], 0.73; 95% CI, 0.47 to 1.15); age 50 years or older at first diagnosis (v <or= 49 years; HR, 0.63; 95% CI, 0.36 to 1.10); use of tamoxifen (HR, 0.59; 95% CI, 0.35 to 1.01); and history of oophorectomy (HR, 0.44; 95% CI, 0.21 to 0.91). The effect of oophorectomy was particularly strong in women first diagnosed prior to age 49 years (HR, 0.24; 95% CI, 0.07 to 0.77). For women who did not have an oophorectomy or take tamoxifen, the 10-year risk of contralateral cancer was 43.4% for BRCA1 carriers and 34.6% for BRCA2 carriers. CONCLUSION: The risk of contralateral breast cancer in women with a BRCA mutation is approximately 40% at 10 years, and is reduced in women who take tamoxifen or who undergo an oophorectomy.

Adult↗

PubMed2004

Pathology of ovarian cancers in BRCA1 and BRCA2 carriers.

PURPOSE: Germline mutations in the BRCA1 and BRCA2 genes confer increased susceptibility to ovarian cancer. There is evidence that tumors in carriers may exhibit a distinct distribution of pathological features, but previous studies on the pathology of such tumors have been small. Our aim was to evaluate the morphologies and immunophenotypes in a large cohort of patients with familial ovarian cancer. EXPERIMENTAL DESIGN: We performed a systematic review of ovarian tumors from 178 BRCA1 mutation carriers, 29 BRCA2 mutation carriers, and 235 controls with a similar age distribution. Tumors were evaluated by four pathologists blinded to mutation status. Both morphological features and immunochemical staining for p53 and HER2 were evaluated. RESULTS: Tumors in BRCA1 mutation carriers were more likely than tumors in age-matched controls to be invasive serous adenocarcinomas (odds ratio, 1.84; 95% confidence interval, 1.21-2.79) and unlikely to be borderline or mucinous tumors. Tumors in BRCA1 carriers were of higher grade (P < 0.0001), had a higher percentage solid component (P = 0.001), and were more likely to stain strongly for p53 (P = 0.018). The distribution of pathological features in BRCA2 carriers was similar to that in BRCA1 carriers. CONCLUSIONS: Use of pathological features can substantially improve the targeting of predictive genetic testing. Results also suggest that BRCA1 and BRCA2 tumors are relatively aggressive and may be expected to have poor prognosis, although this may be treatment dependent.

Adult↗

PubMed2004

Hormone replacement therapy and life expectancy after prophylactic oophorectomy in women with BRCA1/2 mutations: a decision analysis.

PURPOSE: The decision about prophylactic oophorectomy is difficult for many premenopausal women with BRCA1/2 mutations because of concerns and controversy about the use of hormone replacement therapy (HRT) after oophorectomy. PATIENTS AND METHODS: A Markov decision analytic model used the most current epidemiologic data to assess the expected outcomes of prophylactic oophorectomy with or without HRT (to age 50 years or for life) in cohorts of women with BRCA1/2 mutations. Sensitivity analyses were conducted to assess the impact of alternative assumptions about effects of HRT, effects of prophylactic oophorectomy, and risks of cancer associated with BRCA1/2 mutations. RESULTS: In our model, prophylactic oophorectomy lengthened life expectancy in women with BRCA1/2 mutations, irrespective of whether HRT was used after oophorectomy. This gain ranged from 3.34 to 4.65 years, depending on age at oophorectomy. Use of HRT after oophorectomy was associated with relatively small changes in life expectancy (+0.17 to -0.34 years) when HRT was stopped at age 50, but larger decrements in life expectancy if HRT was continued for life (-0.79 to -1.09 years). HRT was associated with a gain in life expectancy of between 0.39 and 0.79 years for mutation carriers undergoing both prophylactic mastectomy and oophorectomy. CONCLUSION: On the basis of the results of this decision analysis, we recommend that women with BRCA1/2 mutations undergo prophylactic oophorectomy after completion of childbearing, decide about short-term HRT after oophorectomy based largely on quality-of-life issues rather than life expectancy, and, if using HRT, consider discontinuing treatment at the time of expected natural menopause, approximately age 50 years.

Adult↗

PubMed2004

Cancer variation associated with the position of the mutation in the BRCA2 gene.

Inherited mutations of the BRCA2 gene give rise to a multi-site cancer phenotype which includes breast cancer (in female and males), ovarian, pancreatic and prostate cancer, ocular and other melanomas, laryngeal, colon and stomach cancers. Interpretation of test results and risk assessment is therefore complex. It has been proposed that families with mutations in the ovarian cancer cluster region (OCCR) of exon 11 (nucleotides 3035-6629) express a higher ratio of ovarian to breast cancer, than families with mutations elsewhere in the BRCA2 gene. In this study we have investigated the presence of 7 types of cancer (ovary, male breast, pancreas, prostate, colon, stomach and melanoma) in first- and second-degree relatives of mutation-positive individuals in 440 families with a BRCA2 mutation. We reviewed histories of cancer in relatives among families with mutations distributed throughout the gene. Families with ovarian cancer were more likely to harbour mutations in the OCCR (nucleotides 3035-6629) than elsewhere in the gene (OR = 2.21; P = 0.0002). We also compared cancer risks according to ethnic group. Ashkenazi Jewish families with the 6174delT founder mutation were more likely to have a family member with ovarian cancer (OR = 1.58; P = 0.002) and less likely to have a family member with prostate cancer (OR = 0.62; P = 0.04) than were non-Jewish families. In contrast, a reduced presence of ovarian cancer was found in families of French-Canadian ancestry, compared to other ancestries (OR = 0.37; P = 0.0026). A high risk of male breast cancer was observed with the 6503delTT mutation (OR = 15.7; P = 0.023). Families of Polish ancestry had a reduced frequency of pancreatic cancer (OR = 0.0; P = 0.03) compared to families of other ethnic origins. In conclusion, both the position of mutation and the ethnic background of the family appear to contribute to the phenotypic variation observed in families with BRCA2 mutations.

BRCA2 Protein↗

PubMed2004

Coronamycins, peptide antibiotics produced by a verticillate Streptomyces sp. (MSU-2110) endophytic on Monstera sp.

Coronamycin is a complex of novel peptide antibiotics with activity against pythiaceous fungi and the human fungal pathogen Cryptococcus neoformans. It is also active against the malarial parasite, Plasmodium falciparum, with an IC(50) of 9.0 ng ml(-1). Coronamycin is produced by a verticillate Streptomyces sp. isolated as an endophyte from an epiphytic vine, Monstera sp., found in the Manu region of the upper Amazon of Peru. Bioassay-guided fractionation of the fermentation broths of this endophyte on silica gel and HPLC chromatography yielded two principal, inseparable, peptides with masses of 1217.9 and 1203.8 Da. Three other minor, but related components, are also present in the preparation. Amino acid analysis of coronamycin revealed residues of component 1, component 2, methionine, tyrosine and leucine at a ratio of 2:2:1:1:3. Other compounds with antifungal activities are also produced by this endophytic streptomycete.

Animals↗

PubMed2004

High-resolution analysis of DNA copy number using oligonucleotide microarrays.

Genomic copy number alterations are a feature of many human diseases including cancer. We have evaluated the effectiveness of an oligonucleotide array, originally designed to detect single-nucleotide polymorphisms, to assess DNA copy number. We first showed that fluorescent signal from the oligonucleotide array varies in proportion to both decreases and increases in copy number. Subsequently we applied the system to a series of 20 cancer cell lines. All of the putative homozygous deletions (10) and high-level amplifications (12; putative copy number >4) tested were confirmed by PCR (either qPCR or normal PCR) analysis. Low-level copy number changes for two of the lines under analysis were compared with BAC array CGH; 77% (n = 44) of the autosomal chromosomes used in the comparison showed consistent patterns of LOH (loss of heterozygosity) and low-level amplification. Of the remaining 10 comparisons that were discordant, eight were caused by low SNP densities and failed in both lines. The studies demonstrate that combining the genotype and copy number analyses gives greater insight into the underlying genetic alterations in cancer cells with identification of complex events including loss and reduplication of loci.

Cell Line↗

PubMed2003

Interleukin-6 -174G-->C polymorphism is associated with improved outcome in high-risk breast cancer.

Axillary lymph node involvement in breast cancer is a marker of recurrence risk. Despite aggressive adjuvant therapy, recurrence in patients with four or more involved lymph nodes approaches 50% at 5 years from diagnosis. Markers that can distinguish those likely to relapse from those likely to be cured are needed to tailor therapy and provide accurate prognostic information to patients. Although most work in this area has focused on tumor characteristics, we hypothesized that the host environment might also play a role in determining risk of relapse. We hypothesized that host inflammatory response, mediated in part by production of interleukin-6 (IL-6), might play a role in the elimination of microscopic residual tumor. Polymorphisms in the IL-6 promoter region appear to modulate serum levels of the cytokine via regulation of gene transcription. A single nucleotide polymorphism involving substitution of cytosine for guanine at position -174 has been associated with reduced transcription and improved outcome in a variety of nonmalignant diseases, including coronary artery disease and several autoimmune conditions. Tumor necrosis factor (TNF) alpha is a proinflammatory cytokine that also plays a role in regulating IL-6 transcription. We hypothesized that polymorphisms in IL-6 (-174 G>C) or TNF-alpha (G-238 or G-308) might be associated with prognosis in a subset of patients with high-risk breast cancer. Genotyping was performed on DNA from stored stem cells in 80 breast cancer patients diagnosed with at least four positive axillary lymph nodes at diagnosis who underwent anthracycline-based adjuvant chemotherapy followed by high-dose multiagent chemotherapy with stem cell rescue. Cox proportional hazards models were used to estimate the effect of genotype and other known prognostic factors on disease-free and overall survival (DFS and OS, respectively). The presence of at least one C allele in the IL-6 promoter at position -174 was significantly associated with both DFS and OS compared with G/G homozygotes. After adjustment for estrogen receptor (ER) status, number of involved lymph nodes, and tumor size, those patients carrying the G/G genotype had a 2.1-fold increase in the rate of failure and a 2.6-fold increase in the rate of death compared with carriers of any C allele at a mean follow-up of 55 months. ER status modulated the effect of IL-6 polymorphism: both DFS and OS were most favorable in patients who were carriers of any C-allele (G/C or C/C) and had ER-positive tumors. The presence of either G/G genotype or an ER-negative tumor increased the hazard of failure [hazard ratio (HR), 2.6 and 3.2, respectively] and death (HR, 2.0 and 2.2, respectively). The combination of both G/G genotype and ER-negative tumor resulted in an additional increase in the hazard of failure (HR, 5.4; four-group comparison, P = 0.003) and death (HR, 6.2; four-group comparison, P = 0.001). TNF-alpha -308 and -238 polymorphisms were not associated with variation in DFS or OS in this cohort. The IL-6-174 promoter polymorphism is associated with clinical outcome in this cohort of node-positive breast cancer patients who received high-dose adjuvant therapy. IL-6 genotype modulated the effect of ER status on outcome. These results support the hypothesis that IL-6 may play an important role in the control of micrometastatic disease in breast cancer. Additional studies are needed to confirm these results and elucidate the mechanisms responsible for these differences.

Adult↗

PubMed2003

Disruption of the expected positive correlation between breast tumor size and lymph node status in BRCA1-related breast carcinoma.

BACKGROUND: A positive correlation between breast tumor size and the number of axillary lymph nodes containing tumor is well established. It has been reported that patients with BRCA1-related breast carcinoma are more likely than patients with nonhereditary breast carcinoma to have negative lymph node status. Therefore, the authors questioned whether the known positive correlation between tumor size and lymph node status also was present in women with BRCA1-related breast carcinomas. METHODS: The relation between the greatest dimension of the resected breast tumor (size) and the presence of positive axillary lymph nodes (expressed as a percentage of all lymph nodes examined) was evaluated in 1555 women with invasive breast carcinoma who were ascertained at 10 centers in North America between 1975 and 1997. There were 276 BRCA1 mutation carriers, 136 BRCA2 carriers, and 1143 women without a known mutation (208 BRCA1/BRCA2 noncarriers and 935 untested women). Patients were stratified according to tumor size, and odds ratios were estimated for the presence of positive lymph nodes with increasing tumor size. RESULTS: A highly significant positive correlation between tumor size and the frequency of positive axillary lymph nodes was seen for BRCA1/BRCA2 noncarriers, for BRCA2 carriers, and for untested women (overall P < 0.0001 for each). In contrast, there was no clear correlation between tumor size and positive lymph node status in BRCA1 carriers (overall P = 0.20). CONCLUSIONS: The relation between tumor size and lymph node status in patients with breast carcinoma appears to be different in BRCA1 carriers compared with BRCA2 carriers and noncarriers. These findings have important implications for estimating the route of metastatic spread and for evaluating the effectiveness of early diagnosis in patients with BRCA1-related breast carcinoma.

Breast Neoplasms↗

PubMed2003

Life insurance and breast cancer risk assessment: adverse selection, genetic testing decisions, and discrimination.

Life insurance industry access to genetic information is controversial. Consumer groups argue that access will increase discrimination in life insurance premiums and discourage individuals from undergoing genetic testing that may provide health benefits. Conversely, life insurers argue that without access to risk information available to individuals, they face substantial financial risk from adverse selection. Given this controversy, we conducted a retrospective cohort study to evaluate the impact of breast cancer risk information on life insurance purchasing, the impact of concerns about life insurance discrimination on use of BRCA1/2 testing, and the incidence of life insurance discrimination following participation in breast cancer risk assessment and BRCA1/2 testing. Study participants were 636 women who participated in genetic counseling and/or genetic testing at a University based clinic offering breast cancer risk assessment, genetic counseling, and BRCA1/2 testing between January 1995 and May 2000. Twenty-seven women (4%) had increased and six (1%) had decreased their life insurance since participation in breast cancer risk assessment. The decision to increase life insurance coverage was associated with predicted breast cancer risk (adjusted OR 1.03 for each 1% absolute increase in risk, 95% CI 1.01-1.10) and being found to carry a mutation in BRCA1/2 (OR 5.10, 95% CI 1.90-13.66). Concern about life insurance discrimination was inversely associated with the decision to undergo BRCA1/2 testing (RR 0.67, 95% CI 0.52-0.85). No respondent reported having life insurance denied or canceled. In this cohort of women, these results indicate that information about increased breast cancer risk is associated with increase in life insurance purchasing, raising the possibility of adverse selection. Although fear of insurance discrimination is associated with the decision not to undergo BRCA1/2 testing, there was no evidence of actual insurance discrimination from BRCA1/2 testing.

Breast Neoplasms↗

PubMed2003

Early use of clinical BRCA1/2 testing: associations with race and breast cancer risk.

When BRCA1/2 testing became commercially available in 1996, many U.S. experts voiced concern about the potential for indiscriminate use of testing among low-risk women. Supporting this concern, several early surveys of interest in genetic testing suggested that genetic testing for cancer susceptibility might appeal most to individuals at low risk of carrying a mutation. To identify factors associated with early use of clinical BRCA1/2 testing, a case-control study was conducted at a large academic health system in the metropolitan Philadelphia region. A total of 167 women underwent genetic counseling for clinical BRCA1/2 testing between 1996 and 1997 (cases) compared with 138 women who were seen in faculty general internal medicine practices over the same period (controls). In this study we measured the risk factors for breast cancer, the risk factors for carrying a BRCA1/2 mutation, and sociodemographic characteristics. Use of BRCA1/2 counseling between 1996 and 1997 was positively associated with family but no personal history of breast cancer (odds ratio (OR), 22.4; 95% confidence interval (CI), 9.3-54.3); family and personal history of breast cancer (OR, 150.3; 95% CI, 24.1-939.6); being Caucasian and non-Jewish (OR, 4.1; 95% CI, 1.3-13.5); being Caucasian and Jewish (OR, 8.8; 95% CI, 2.2-35.5); and being married (OR, 3.2; 95% CI, 1.6-6.3). Use of BRCA1/2 counseling was inversely associated with increasing age (OR, 0.07; 95% CI, 0.02-0.28 for >60 compared to <50). As suggested by the association with family history, use of counseling was associated with having a higher predicted risk of breast cancer and a higher predicted risk of carrying a BRCA1 mutation (P < 0.0001). Women who sought clinical BRCA1/2 testing in the year after it became commercially available were not the "worried well," but women at significantly increased risk of carrying a mutation. However, even after adjusting for breast cancer risk, there was a substantial racial disparity in use of BRCA1/2 testing. These findings suggest that ensuring equal access to testing for high-risk individuals irrespective of race may be as important for the future of predictive genetic testing as restricting the use of testing among low-risk individuals.

Adult↗

PubMed2003

The Cancer Genetics Network: recruitment results and pilot studies.

OBJECTIVE: The National Cancer Institute established the Cancer Genetics Network (CGN) to support collaborative investigations into the genetic basis of cancer susceptibility, explore mechanisms to integrate this new knowledge into medical practice, and identify ways of addressing the associated psychosocial, ethical, legal, and public health issues. SUBJECTS AND METHODS: The CGN has developed the complex infrastructure required to support the projects, including the establishment of guidelines and policies, uniform methods, standard questionnaires to be used by all of the centers, and a standard format for submission of data to the Informatics Center. Cancer patients and their family members have been invited to enroll and be included in a pool of potential study participants. The Information Technology Group is responsible for support of the design, implementation, and maintenance of the multicenter Network-wide research protocols. RESULTS: As of January 2004, the CGN contained data on 23,995 probands (participants) and 425,798 family members. As a resource for cancer genetic studies, the CGN has a large number of probands and first-degree relatives with and without cancer and with multiple ethnicities. Different study designs can be used including case-control, case-case, and family studies. CONCLUSIONS: The unique resources of the CGN are available for studies on cancer genetic susceptibility, translational research, and behavioral research. The CGN is now at a point where approved collaborators may have access to enrolled patients and their families for special studies, as well as to the clinical, environmental and family cancer history data banked in the Informatics Center.

Female↗

PubMed2002

Oral contraceptives and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Oral contraceptive use has been associated with an increase in the risk of breast cancer in young women. We examined whether this association is seen in women at high risk of breast cancer because they carry a mutation in one of two breast cancer susceptibility genes, BRCA1 and BRCA2. METHODS: We performed a matched case-control study on 1311 pairs of women with known deleterious BRCA1 and/or BRCA2 mutations recruited from 52 centers in 11 countries. Women who had been diagnosed with breast cancer were matched to control subjects by year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of ovarian cancer. All study subjects completed a questionnaire about oral contraceptive use. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. All statistical tests were two-sided. RESULTS: Among BRCA2 mutation carriers, ever use of oral contraceptives was not associated with an increased risk of breast cancer (OR = 0.94, 95% CI = 0.72 to 1.24). For BRCA1 mutation carriers, ever use of oral contraceptives was associated with a modestly increased risk of breast cancer (OR = 1.20, 95% CI = 1.02 to 1.40). However, compared with BRCA1 mutation carriers who never used oral contraceptives, those who used oral contraceptives for at least 5 years had an increased risk of breast cancer (OR = 1.33, 95% CI = 1.11 to 1.60), as did those who used oral contraceptives before age 30 (OR = 1.29, 95% CI = 1.09 to 1.52), those who were diagnosed with breast cancer before age 40 (OR = 1.38, 95% CI = 1.11 to 1.72), and those who first used oral contraceptives before 1975 (OR = 1.42, 95% CI = 1.17 to 1.75). CONCLUSIONS: Among BRCA1 mutation carriers, women who first used oral contraceptives before 1975, who used them before age 30, or who used them for 5 or more years may have an increased risk of early-onset breast cancer. Oral contraceptives do not appear to be associated with risk of breast cancer in BRCA2 carriers, but data for BRCA2 carriers are limited.

Adolescent↗

PubMed2002

Low-penetrance susceptibility to breast cancer due to CHEK2(*)1100delC in noncarriers of BRCA1 or BRCA2 mutations.

Mutations in BRCA1 and BRCA2 confer a high risk of breast and ovarian cancer, but account for only a small fraction of breast cancer susceptibility. To find additional genes conferring susceptibility to breast cancer, we analyzed CHEK2 (also known as CHK2), which encodes a cell-cycle checkpoint kinase that is implicated in DNA repair processes involving BRCA1 and p53 (refs 3,4,5). We show that CHEK2(*)1100delC, a truncating variant that abrogates the kinase activity, has a frequency of 1.1% in healthy individuals. However, this variant is present in 5.1% of individuals with breast cancer from 718 families that do not carry mutations in BRCA1 or BRCA2 (P = 0.00000003), including 13.5% of individuals from families with male breast cancer (P = 0.00015). We estimate that the CHEK2(*)1100delC variant results in an approximately twofold increase of breast cancer risk in women and a tenfold increase of risk in men. By contrast, the variant confers no increased cancer risk in carriers of BRCA1 or BRCA2 mutations. This suggests that the biological mechanisms underlying the elevated risk of breast cancer in CHEK2 mutation carriers are already subverted in carriers of BRCA1 or BRCA2 mutations, which is consistent with participation of the encoded proteins in the same pathway.

Breast Neoplasms↗

PubMed2002

Interest in BRCA1/2 testing in a primary care population.

BACKGROUND: Mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 are found in less than 1/1,000 women in the general population. Experts and professional organizations recommend targeting testing to women with risk factors for carrying a mutation. Over the next decade, BRCA1/2 testing is likely to become substantially less expensive and to move into primary care practice where pretest counseling may be limited. METHODS: The objective of the study was to investigate the factors associated with interest in BRCA1/2 testing among primary care patients receiving only limited information about testing. The design was a cross-sectional mailed survey. The setting was a University-based health system in the metropolitan Philadelphia region. The participants were 400 adult women cared for in a faculty General Internal Medicine practice. RESULTS: Two hundred forty-two women (71%) completed surveys; 53% of respondents were aware of BRCA1/2 testing and 58% were interested in undergoing testing if it was both convenient and affordable. Thirty-one percent were both aware of and interested in testing. Awareness of testing was inversely associated with African-American race (OR 0.56, 95% CI 0.38-0.83) and positively associated with college education (OR 2.21, 95% CI 1.23-3.94). Interest in testing was inversely associated with a family history of breast cancer (OR 0.45, 95% CI 0.23-0.92) and increasing age (OR 0.97, 95% CI 0.95-0.99). The inverse association between family history and interest in testing persisted in the subgroup of women who were aware of testing (OR 0.55, 95% CI 0.30-0.98). CONCLUSIONS: Among a primary care population, African-American women are less aware of BRCA1/2 testing and, when provided only limited information about BRCA1/2 testing, women at lowest risk of carrying a mutation are most interested in undergoing BRCA1/2 testing. Challenges of moving BRCA1/2 testing into primary care practice include both limiting indiscriminate use by the "worried well" and, as proven cancer prevention strategies become available, ensuring access to all high-risk women regardless of race.

Adult↗