Prue Weideman

Tamoxifen and Risk of Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers

PURPOSE To determine whether adjuvant tamoxifen treatment for breast cancer (BC) is associated with reduced contralateral breast cancer (CBC) risk for BRCA1 and/or BRCA2 mutation carriers. METHODS Analysis of pooled observational cohort data, self-reported at enrollment and at follow-up from the International BRCA1, and BRCA2 Carrier Cohort Study, Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer, and Breast Cancer Family Registry. Eligible women were BRCA1 and BRCA2 mutation carriers diagnosed with unilateral BC since 1970 and no other invasive cancer or tamoxifen use before first BC. Hazard ratios (HRs) for CBC associated with tamoxifen use were estimated using Cox regression, adjusting for year and age of diagnosis, country, and bilateral oophorectomy and censoring at contralateral mastectomy, death, or loss to follow-up. RESULTS Of 1,583 BRCA1 and 881 BRCA2 mutation carriers, 383 (24%) and 454 (52%), respectively, took tamoxifen after first BC diagnosis. There were 520 CBCs over 20,104 person-years of observation. The adjusted HR estimates were 0.38 (95% CI, 0.27 to 0.55) and 0.33 (95% CI, 0.22 to 0.50) for BRCA1 and BRCA2 mutation carriers, respectively. After left truncating at recruitment to the cohort, adjusted HR estimates were 0.58 (95% CI, 0.29 to 1.13) and 0.48 (95% CI, 0.22 to 1.05) based on 657 BRCA1 and 426 BRCA2 mutation carriers with 100 CBCs over 4,392 person-years of prospective follow-up. HRs did not differ by estrogen receptor status of the first BC (missing for 56% of cases). CONCLUSION This study provides evidence that tamoxifen use is associated with a reduction in CBC risk for BRCA1 and BRCA2 mutation carriers. Further follow-up of these cohorts will provide increased statistical power for future prospective analyses.

Risk‐reducing surgery, screening and chemoprevention practices of BRCA1 and BRCA2 mutation carriers: a prospective cohort study

This study prospectively evaluated the utilization of cancer risk management strategies in a multi‐institutional cohort of BRCA1 and BRCA2 mutation carriers using a self‐report questionnaire. Of 142 unaffected female mutation carriers, 70 (49%) had elected to receive their mutation result. Of those who knew their mutation result, 11% underwent bilateral mastectomy (BM), 29% had bilateral oophorectomy (BO), 78% performed regular breast self‐examination (BSE), and 80%, 89%, 67%, and 0% had at least annual clinical breast examination (CBE), mammography, transvaginal ultrasound (TVU), and CA125, respectively. A further 20%, 7%, 0%, 21%, and 75%, respectively, reported never having had these tests. For women who elected not to receive their mutation result, 0% underwent BM, 6% underwent BO, and 77%, 42%, 56%, 7%, and 0% had regular BSE, CBE, mammography, TVU, and CA125, respectively. Only one woman used chemoprevention outside a clinical trial. Uptake of prophylactic surgery and screening was associated with knowing one’s mutation status (for all behaviors except BSE), age (for BO and CBE) and residence (for mammography). In this cohort, the minority of mutation carriers utilized risk‐reducing surgery or chemoprevention and a substantial minority were not undergoing regular cancer‐screening tests.

Screening for ovarian cancer using serum CA125 and vaginal examination: report on 2550 females

This study was undertaken to assess the effectiveness of using serum CA125 and vaginal examination as a screening test for ovarian cancer in apparently healthy females. Two thousand five hundred and fifty healthy females aged 40 and over were recruited to participate in a screening study involving a questionnaire, serum CA125 measurement and vaginal examination. Females with either an elevated CA125 level or abnormal vaginal examination had a pelvic ultrasound performed as a secondary procedure. The positive predictive values of an elevated serum CA125 level, and a combination of CA125 level measurement and vaginal examination for ovarian cancer, were 1/100 and 1/3, respectively. The specificities of serum CA125 levels, vaginal examination and both in combination were 96.1%, 98.5% and 99.9%, respectively. In postmenopausal females the positive predictive values were improved with CA125 measurement alone, giving a positive predictive value of 1/24. Seventeen females underwent operative procedure as a result of the screening—only one of these was for an ovarian cancer. The combination of serum CA125 measurement and vaginal examination is not an effective screening test in the general population, although in postmenopausal females it does achieve acceptable specificities and positive predictive values.

Predictors of participation in clinical and psychosocial follow-up of the kConFab breast cancer family cohort

Introduction : Prospective collection of epidemiological, psychosocial and outcome data in large breast cancer family cohorts should provide less biased data than retrospective studies regarding penetrance of breast cancer and modifiers of genetic risk. Methods: The Kathleen Cuningham Foundation for Research into Breast Cancer (kConFab) recently commenced 3-yearly follow-up on over 750 families with multiple cases of breast cancer. Clinical follow-up was by mailed self-report questionnaire to all participants, while psychosocial follow-up was only of unaffected women and consisted of two components: a mailed questionnaire and an interview regarding stressful life events. Results: To date, 1928 of 2748 (70%) participants returned the clinical follow-up questionnaire (10% opted out, 16% were non-responders, and 4% were not contactable). Of the unaffected females who returned the clinical follow-up questionnaire, 91% participated in the psychosocial follow-up. In multivariate analyses, sex, personal cancer status, marital status, age and educational status were independent predictors of response to the clinical follow-up questionnaire, and number of female children, age, and family history of breast cancer were independent predictors of response to the psychosocial follow-up. Conclusions: A first round of 3-yearly clinical and psychosocial follow-up using a mailed questionnaire was feasible in this cohort. High response rates were achieved by employing intensive tracing and reminder strategies. The predictors of response for the clinical and psychosocial follow-up components of this study should be considered in designing similar follow-up strategies for other family cancer cohorts.

Preventing breast and ovarian cancers in high-risk BRCA1 and BRCA2 mutation carriers

Objective: To estimate the prevalence of the use of cancer risk‐reducing measures among Australian BRCA1 and BRCA2 mutation carriers.

The effect of the menstrual cycle on serum CA 125 levels: A population study

OBJECTIVE Our objective was to assess the effect of the menstrual cycle on CA 125 levels in a population study. STUDY DESIGN Serum CA 125 was measured in 1478 women, with day of menstrual cycle noted in 574 women. Repeat examination was performed in women with elevated results, and 40 of these women were tracked by weekly examination of CA 125 levels. RESULTS A significant difference was demonstrated when midcycle samples were compared with day 1 and day 28 samples (p < 0.05). In spite of this significance the difference was not clinically useful. Elevated serum CA 125 (> 35 U/ml) levels were present in 77 (5.2%) of the premenopausal women. A significant variation was demonstrable with higher CA 125 levels about the time of menstruation in 29 of the 40 women tracked. CONCLUSION This study suggests that in the population as a whole the effect of the menstrual cycle on serum CA 125 is not clinically significant, but single elevated levels in an individual may represent menstrual fluctuation.

Do BRCA1 and BRCA2 Mutation Carriers Have Earlier Natural Menopause Than Their Noncarrier Relatives? Results From the Kathleen Cuningham Foundation Consortium for Research Into Familial Breast Cancer

PURPOSE Limited data suggest that germline BRCA1 mutations are associated with occult primary ovarian insufficiency and that BRCA1 and BRCA2 mutation carriers might have earlier natural menopause (NM) than their noncarrier relatives. PATIENTS AND METHODS Eligible women were mutation carriers and noncarriers from families segregating a BRCA1 or BRCA2 mutation. Data were self-reported using uniform questionnaires at cohort entry and every 3 years thereafter. NM was defined as the cessation of menses for 12 months without another cause. Cox proportional hazards analysis modeled time from birth to NM, adjusting for multiple potential confounders. Analysis time was censored at the earliest of the following: last follow-up, bilateral oophorectomy, hysterectomy, commencement of hormone therapy, insertion of intrauterine device, or any cancer diagnosis. Hazard ratios (HRs) were estimated as a measure of how likely mutation carriers are, relative to noncarriers, to reach NM at a given age. RESULTS A total of 1,840 women were eligible for analysis. Overall only 19% reached NM. A lower proportion of BRCA1 and BRCA2 mutation carriers reached NM compared with noncarriers. Conversely, a higher proportion of mutation carriers were censored at cancer diagnosis or oophorectomy than noncarriers. The adjusted HR estimates for NM were 1.03 (95% CI, 0.75 to 1.40; P = .9) for 445 BRCA1 mutation carriers and 559 noncarrier relatives and 1.01 (95% CI, 0.71 to 1.42; P = .9) for 374 BRCA2 mutation carriers and 462 noncarrier relatives. CONCLUSION We found no evidence that BRCA1 and BRCA2 mutation carriers are at higher risk of NM at a given age than their noncarrier relatives.

Prospective validation of the breast cancer risk prediction model BOADICEA and a batch-mode version BOADICEACentre.

Background:Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) is a risk prediction algorithm that can be used to compute estimates of age-specific risk of breast cancer. It is uncertain whether BOADICEA performs adequately for populations outside the United Kingdom.Methods:Using a batch mode version of BOADICEA that we developed (BOADICEACentre), we calculated the cumulative 10-year invasive breast cancer risk for 4176 Australian women of European ancestry unaffected at baseline from 1601 case and control families in the Australian Breast Cancer Family Registry. Based on 115 incident breast cancers, we investigated calibration, discrimination (using receiver-operating characteristic (ROC) curves) and accuracy at the individual level.Results:The ratio of expected to observed number of breast cancers was 0.92 (95% confidence interval (CI) 0.76–1.10). The E/O ratios by subgroups of the participant’s relationship to the index case and by the reported number of affected relatives ranged between 0.83 and 0.98 and all 95% CIs included 1.00. The area under the ROC curve was 0.70 (95% CI 0.66–0.75) and there was no evidence of systematic under- or over-dispersion (P=0.2).Conclusion:BOADICEA is well calibrated for Australian women, and had good discrimination and accuracy at the individual level.

Predictors of the use of complementary and alternative medicine (CAM) by women at high risk for breast cancer

BACKGROUND Few data exist regarding the use of complementary and alternative medicine (CAM) by unaffected women at high risk of breast cancer. METHODS Self-reported CAM use by women from multiple-case breast cancer families was obtained by questionnaire. Factors associated with CAM use were assessed using multiple logistic regression. RESULTS Of 892 women, 55% (n=489) used CAM, 6% (n=53) specifically to prevent cancer. CAM use was independently associated with tertiary education level (OR 2.56, 95% CI 1.83-3.58, p<0.001), greater physical activity (OR 1.05 per hour of physical activity/week, 95% CI 1.00-1.10, p=0.049), greater anxiety (OR 1.92, 95% CI 1.16-3.16, p=0.01), not currently smoking (OR 0.64, 95% CI 0.42-0.97, p=0.037) and lower perceived BC risk (OR 0.82 per 20 percentage points, 95% CI 0.72-0.94, p=0.005). CONCLUSIONS The majority of high-risk women use CAM, but mostly for reasons other than cancer prevention. Most predictors of CAM use are consistent with the limited literature for women at high risk for cancer.

Cancer Risk Management Practices of Noncarriers Within BRCA1/2 Mutation–Positive Families in the Kathleen Cuningham Foundation Consortium for Research Into Familial Breast Cancer

PURPOSE Women from BRCA mutation-positive families who do not carry the family-specific mutation are generally at average cancer risk and therefore do not require intensive risk management. METHODS Participants were female noncarriers from BRCA mutation-positive families who had responded to 3 yearly follow-up questionnaires and had chosen to either receive or not receive their genetic test result. In the former group, undertaking mammography younger than age 40 years or more than once every 2 years, clinical breast examination (CBE) more than yearly, breast self-examination (BSE) more than monthly, or any transvaginal ultrasound (TVU) or CA-125 was considered overscreening. Screening behaviors of women who did and did not know their genetic test result were compared. Logistic regression and nonparametric analyses were performed to identify demographic and psychosocial factors (respectively) associated with overscreening. RESULTS Of 325 eligible women, 116 knew their mutation status and 209 did not. For the first group, proportions overscreening were mammography, 53%; CBE, 10%; BSE, 11%; TVU, 7%; and CA-125, 10%. There were no significant differences in screening behaviors between the groups. In those aware of their mutation status, parous women were more likely to overuse mammography (odds ratio [OR] = 4.4; 95% CI, 1.1 to 17; P = .03) and women with one or more first-degree relative with ovarian cancer (OC) were more likely to overuse OC screening (TVU: OR = 6.00; 95% CI, 1.0 to 35.1; P = .047, and CA-125: OR = 6.50; 95% CI, 1.49 to 28.4; P = .013). CONCLUSION The reasons for overuse of screening (particularly mammography) by mutation noncarriers require additional elucidation given the potential for harm.