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

Hormonal Contraception and Breast Cancer Risk for Carriers of Germline Mutations in BRCA1 and BRCA2

PURPOSE

It is uncertain whether, and to what extent, hormonal contraceptives increase breast cancer (BC) risk for germline BRCA1 or BRCA2 mutation carriers.

METHODS

Using pooled observational data from four prospective cohort studies, associations between hormonal contraceptive use and BC risk for unaffected female BRCA1 and BRCA2 mutation carriers were assessed using Cox regression.

RESULTS

Of 3,882 BRCA1 and 1,509 BRCA2 mutation carriers, 53% and 71%, respectively, had ever used hormonal contraceptives for at least 1 year (median cumulative duration of use, 4.8 and 5.7 years, respectively). Overall, 488 BRCA1 and 191 BRCA2 mutation carriers developed BC during median follow-up of 5.9 and 5.6 years, respectively. Although for BRCA1 mutation carriers, neither current nor past use of hormonal contraceptives for at least 1 year was statistically significantly associated with BC risk (hazard ratio [HR], 1.40 [95% CI, 0.94 to 2.08], P = .10 for current use; 1.16 [0.80 to 1.69], P = .4, 1.40 [0.99 to 1.97], P = .05, and 1.27 [0.98 to 1.63], P = .07 for past use 1-5, 6-10, and >10 years before, respectively), ever use was associated with increased risk (HR, 1.29 [95% CI, 1.04 to 1.60], P = .02). Furthermore, BC risk increased with longer cumulative duration of use, with an estimated proportional increase in risk of 3% (1%-5%, P = .002) for each additional year of use. For BRCA2 mutation carriers, there was no evidence that current or ever use was associated with increased BC risk (HR, 0.70 [95% CI, 0.33 to 1.47], P = .3 and 1.07 [0.73 to 1.57], P = .7, respectively).

CONCLUSION

Hormonal contraceptives were associated with increased BC risk for BRCA1 mutation carriers, especially if used for longer durations. Decisions about their use in women with BRCA1 mutations should carefully weigh the risks and benefits for each individual.

Pregnancy-Related Factors and Breast Cancer Risk for Women Across a Range of Familial Risk

Importance

Few studies have investigated whether the associations between pregnancy-related factors and breast cancer (BC) risk differ by underlying BC susceptibility. Evidence regarding variation in BC risk is critical to understanding BC causes and for developing effective risk-based screening guidelines.

Objective

To examine the association between pregnancy-related factors and BC risk, including modification by a of BC where scores are based on age and BC family history.

Design, Setting, and Participants

This cohort study included participants from the prospective Family Study Cohort (ProF-SC), which includes the 6 sites of the Breast Cancer Family Registry (US, Canada, and Australia) and the Kathleen Cuningham Foundation Consortium (Australia). Analyses were performed in a cohort of women enrolled from 1992 to 2011 without any personal history of BC who were followed up through 2017 with a median (range) follow-up of 10 (1-23) years. Data were analyzed from March 1992 to March 2017.

Exposures

Parity, number of full-term pregnancies (FTP), age at first FTP, years since last FTP, and breastfeeding.

Main Outcomes and Measures

BC diagnoses were obtained through self-report or report by a first-degree relative and confirmed through pathology and data linkages. Cox proportional hazards regression models estimated hazard ratios (HR) and 95% CIs for each exposure, examining modification by PARS of BC. Differences were assessed by estrogen receptor (ER) subtype.

Results

The study included 17 274 women (mean [SD] age, 46.7 [15.1] years; 791 African American or Black participants [4.6%], 1399 Hispanic or Latinx participants [8.2%], and 13 790 White participants [80.7%]) with 943 prospectively ascertained BC cases. Compared with nulliparous women, BC risk was higher after a recent pregnancy for those women with higher PARS (last FTP 0-5 years HR for interaction, 1.53; 95% CI, 1.13-2.07; P for interaction < .001). Associations between other exposures were limited to ER-negative disease. ER-negative BC was positively associated with increasing PARS and increasing years since last FTP (P for interaction < .001) with higher risk for recent pregnancy vs nulliparous women (last FTP 0-5 years HR for interaction, 1.54; 95% CI, 1.03-2.31). ER-negative BC was positively associated with increasing PARS and being aged 20 years or older vs less than 20 years at first FTP (P for interaction = .002) and inversely associated with multiparity vs nulliparity (P for interaction = .01).

Conclusions and Relevance

In this cohort study of women with no prior BC diagnoses, associations between pregnancy-related factors and BC risk were modified by PARS, with greater associations observed for ER-negative BC.

Associations of height, body mass index, and weight gain with breast cancer risk in carriers of a pathogenic variant in BRCA1 or BRCA2: the BRCA1 and BRCA2 Cohort Consortium

INTRODUCTION

Height, body mass index (BMI), and weight gain are associated with breast cancer risk in the general population. It is unclear whether these associations also exist for carriers of pathogenic variants in the BRCA1 or BRCA2 genes.

PATIENTS AND METHODS

An international pooled cohort of 8091 BRCA1/2 variant carriers was used for retrospective and prospective analyses separately for premenopausal and postmenopausal women. Cox regression was used to estimate breast cancer risk associations with height, BMI, and weight change.

RESULTS

In the retrospective analysis, taller height was associated with risk of premenopausal breast cancer for BRCA2 variant carriers (HR 1.20 per 10 cm increase, 95% CI 1.04-1.38). Higher young-adult BMI was associated with lower premenopausal breast cancer risk for both BRCA1 (HR 0.75 per 5 kg/m2, 95% CI 0.66-0.84) and BRCA2 (HR 0.76, 95% CI 0.65-0.89) variant carriers in the retrospective analysis, with consistent, though not statistically significant, findings from the prospective analysis. In the prospective analysis, higher BMI and adult weight gain were associated with higher postmenopausal breast cancer risk for BRCA1 carriers (HR 1.20 per 5 kg/m2, 95% CI 1.02-1.42; and HR 1.10 per 5 kg weight gain, 95% CI 1.01-1.19, respectively).

CONCLUSION

Anthropometric measures are associated with breast cancer risk for BRCA1 and BRCA2 variant carriers, with relative risk estimates that are generally consistent with those for women from the general population.

Recreational Physical Activity and Outcomes After Breast Cancer in Women at High Familial Risk

Background

Recreational physical activity (RPA) is associated with improved survival after breast cancer (BC) in average-risk women, but evidence is limited for women who are at increased familial risk because of a BC family history or BRCA1 and BRCA2 pathogenic variants (BRCA1/2 PVs).

Methods

We estimated associations of RPA (self-reported average hours per week within 3 years of BC diagnosis) with all-cause mortality and second BC events (recurrence or new primary) after first invasive BC in women in the Prospective Family Study Cohort (n = 4610, diagnosed 1993-2011, aged 22-79 years at diagnosis). We fitted Cox proportional hazards regression models adjusted for age at diagnosis, demographics, and lifestyle factors. We tested for multiplicative interactions (Wald test statistic for cross-product terms) and additive interactions (relative excess risk due to interaction) by age at diagnosis, body mass index, estrogen receptor status, stage at diagnosis, BRCA1/2 PVs, and familial risk score estimated from multigenerational pedigree data. Statistical tests were 2-sided.

Results

We observed 1212 deaths and 473 second BC events over a median follow-up from study enrollment of 11.0 and 10.5 years, respectively. After adjusting for covariates, RPA (any vs none) was associated with lower all-cause mortality of 16.1% (95% confidence interval [CI] = 2.4% to 27.9%) overall, 11.8% (95% CI = -3.6% to 24.9%) in women without BRCA1/2 PVs, and 47.5% (95% CI = 17.4% to 66.6%) in women with BRCA1/2 PVs (RPA*BRCA1/2 multiplicative interaction P = .005; relative excess risk due to interaction = 0.87, 95% CI = 0.01 to 1.74). RPA was not associated with risk of second BC events.

Conclusion

Findings support that RPA is associated with lower all-cause mortality in women with BC, particularly in women with BRCA1/2 PVs.

Underutilisation of breast cancer prevention medication in Australia

Increased implementation of proven prevention strategies is required to combat rising breast cancer incidence. We assessed use of risk reducing medication (RRMed) by Australian women at elevated breast cancer risk. Only 2.4% had ever used RRMed. Higher breast cancer risk was statistically significantly associated with use of RRMed (OR 1.82, 95%CI: 1.08–3.07, p = 0.02 for ≥30% lifetime risk compared with 16%–29% lifetime risk), but parity, education level and family history of breast cancer were not. Breast cancer prevention medications are underutilised. Efforts are needed to incorporate breast cancer risk assessment and risk management discussions into routine health assessments for women.

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Risk-reducing medication is infrequently used by Australian women at increased risk of breast cancer.

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Higher breast cancer risk is associated with greater uptake of risk reducing medication, but not with adherence.

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Routine breast cancer risk assessment may increase risk reducing medication use.

Survival from breast cancer in women with a BRCA2 mutation by treatment

BACKGROUND

The impact of various breast-cancer treatments on patients with a BRCA2 mutation has not been studied. We sought to estimate the impact of bilateral oophorectomy and other treatments on breast cancer-specific survival among patients with a germline BRCA2 mutation.

METHODS

We identified 664 women with stage I-III breast cancer and a BRCA2 mutation by combining five different datasets (retrospective and prospective). Subjects were followed for 7.2 years from diagnosis to death from breast cancer. Tumour characteristics and cancer treatments were patient-reported and derived from medical records. Predictors of survival were determined using Cox proportional hazard models, adjusted for other treatments and for prognostic features.

RESULTS

The 10-year breast-cancer survival for ER-positive patients was 78.9% and for ER-negative patients was 82.3% (adjusted HR = 1.23 (95% CI, 0.62-2.45, p = 0.55)). The 10-year breast-cancer survival for women who had a bilateral oophorectomy was 89.1% and for women who did not have an oophorectomy was 59.0% (adjusted HR = 0.45; 95% CI, 0.28-0.72, p = 0.001). The adjusted hazard ratio for chemotherapy was 0.83 (95% CI, 0.65-1.53: p = 0.56).

CONCLUSIONS

For women with breast cancer and a germline BRCA2 mutation, positive ER status does not predict superior survival. Oophorectomy is associated with a reduced risk of death from breast cancer and should be considered in the treatment plan.

Motivators of Inappropriate Ovarian Cancer Screening: A Survey of Women and Their Clinicians

Background

This study examined why women and doctors screen for ovarian cancer (OC) contrary to guidelines.

Methods

Surveys, based on the Theoretical Domains Framework, were sent to women in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer and family physicians and gynecologists who organized their screening.

Results

Of 1264 Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer women, 832 (65.8%) responded. In the past 2 years, 126 (15.1%) had screened. Most of these (n = 101, 80.2%) would continue even if their doctor told them it is ineffective. For women, key OC screening motivators operated in the domains of social role and goals (staying healthy for family, 93.9%), emotion and reinforcement (peace of mind, 93.1%), and beliefs about capabilities (tests are easy to have, 91.9%). Of 531 clinicians 252 (47.5%) responded; a minority (family physicians 45.8%, gynecologists 16.7%) thought OC screening was useful. For gynecologists, the main motivators of OC screening operated in the domains of environmental context (lack of other screening options, 27.6%), and emotion (patient peace of mind, 17.2%; difficulty discontinuing screening, 13.8%). For family physicians,, the strongest motivators were in the domains of social influence (women ask for these tests, 20.7%), goals (a chance these tests will detect cancer early, 16.4%), emotion (patient peace of mind, 13.8%), and environmental context (no other OC screening options, 11.2%).

Conclusion

Reasons for OC screening are mostly patient driven. Clinician knowledge and practice are discordant. Motivators of OC screening encompass several domains, which could be targeted in interventions to reduce inappropriate OC screening.

Comparing 5-Year and Lifetime Risks of Breast Cancer using the Prospective Family Study Cohort

BACKGROUND

Clinical guidelines often use predicted lifetime risk from birth to define criteria for making decisions regarding breast cancer screening rather than thresholds based on absolute 5-year risk from current age.

METHODS

We used the Prospective Family Cohort Study of 14 657 women without breast cancer at baseline in which, during a median follow-up of 10 years, 482 women were diagnosed with invasive breast cancer. We examined the performances of the International Breast Cancer Intervention Study (IBIS) and Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) risk models when using the alternative thresholds by comparing predictions based on 5-year risk with those based on lifetime risk from birth and remaining lifetime risk. All statistical tests were 2-sided.

RESULTS

Using IBIS, the areas under the receiver-operating characteristic curves were 0.66 (95% confidence interval = 0.63 to 0.68) and 0.56 (95% confidence interval = 0.54 to 0.59) for 5-year and lifetime risks, respectively (Pdiff < .001). For equivalent sensitivities, the 5-year incidence almost always had higher specificities than lifetime risk from birth. For women aged 20-39 years, 5-year risk performed better than lifetime risk from birth. For women aged 40 years or older, receiver-operating characteristic curves were similar for 5-year and lifetime IBIS risk from birth. Classifications based on remaining lifetime risk were inferior to 5-year risk estimates. Results were similar using BOADICEA.

CONCLUSIONS

Our analysis shows that risk stratification using clinical models will likely be more accurate when based on predicted 5-year risk compared with risks based on predicted lifetime and remaining lifetime, particularly for women aged 20-39 years.

Breast Cancer Chemoprevention: Use and Views of Australian Women and Their Clinicians

Guidelines endorse the use of chemoprevention for breast cancer risk reduction. This study examined the barriers and facilitators to chemoprevention use for Australian women at increased risk of breast cancer, and their clinicians. Surveys, based on the Theoretical Domains Framework, were mailed to 1,113 women at ≥16% lifetime risk of breast cancer who were enrolled in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer cohort study (kConFab), and their 524 treating clinicians. Seven hundred twenty-five women (65%) and 221 (42%) clinicians responded. Only 10 (1.4%) kConFab women had ever taken chemoprevention. Three hundred seventy-eight (52%) kConFab women, two (3%) breast surgeons, and 51 (35%) family physicians were not aware of chemoprevention. For women, the strongest barriers to chemoprevention were side effects (31%) and inadequate information (23%), which operate in the Theoretical Domains Framework domains of "beliefs about consequences" and "knowledge," respectively. Strongest facilitators related to tamoxifen's long-term efficacy (35%, "knowledge," "beliefs about consequences," and "goals" domains), staying healthy for family (13%, "social role" and "goals" domains), and abnormal breast biopsy (13%, "environmental context" domain). The strongest barrier for family physicians was insufficient knowledge (45%, "knowledge" domain) and for breast surgeons was medication side effects (40%, "beliefs about consequences" domain). The strongest facilitators for both clinician groups related to clear guidelines, strong family history, and better tools to select patients ("environmental context and resources" domain). Clinician knowledge and resources, and beliefs about the side-effect consequences of chemoprevention, are key domains that could be targeted to potentially enhance uptake. PREVENTION RELEVANCE: Despite its efficacy in reducing breast cancer incidence, chemoprevention is underutilised. This survey study of Australian women and their clinicians used behavioural change theory to identify modifiable barriers to chemoprevention uptake, and to suggest interventions such as policy change, educational resources and public campaigns, that may increase awareness and use.See related Spotlight by Vogel, p. 1.

Considerations When Using Breast Cancer Risk Models for Women with Negative BRCA1/BRCA2 Mutation Results

The performance of breast cancer risk models for women with a family history but negative BRCA1 and/or BRCA2 mutation test results is uncertain. We calculated the cumulative 10-year invasive breast cancer risk at cohort entry for 14 657 unaffected women (96.1% had an affected relative) not known to carry BRCA1 or BRCA2 mutations at baseline using three pedigree-based models (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm, BRCAPRO, and International Breast Cancer Intervention Study). During follow-up, 482 women were diagnosed with invasive breast cancer. Mutation testing was conducted independent of incident cancers. All models underpredicted risk by 26.3%-56.7% for women who tested negative but whose relatives had not been tested (n = 1363; 63 breast cancers). Although replication studies with larger sample sizes are needed, until these models are recalibrated for women who test negative and have no relatives tested, caution should be used when considering changing the breast cancer risk management intensity of such women based on risk estimates from these models.

Alcohol Consumption, Cigarette Smoking, and Risk of Breast Cancer for BRCA1 and BRCA2 Mutation Carriers: Results from The BRCA1 and BRCA2 Cohort Consortium

BACKGROUND

Tobacco smoking and alcohol consumption have been intensively studied in the general population to assess their effects on the risk of breast cancer, but very few studies have examined these effects in BRCA1 and BRCA2 mutation carriers. Given the high breast cancer risk for mutation carriers and the importance of BRCA1 and BRCA2 in DNA repair, better evidence on the associations of these lifestyle factors with breast cancer risk is essential.

METHODS

Using a large international pooled cohort of BRCA1 and BRCA2 mutation carriers, we conducted retrospective (5,707 BRCA1 mutation carriers and 3,525 BRCA2 mutation carriers) and prospective (2,276 BRCA1 mutation carriers and 1,610 BRCA2 mutation carriers) analyses of alcohol and tobacco consumption using Cox proportional hazards models.

RESULTS

For both BRCA1 and BRCA2 mutation carriers, none of the smoking-related variables was associated with breast cancer risk, except smoking for more than 5 years before a first full-term pregnancy (FFTP) when compared with parous women who never smoked. For BRCA1 mutation carriers, the HR from retrospective analysis (HRR) was 1.19 [95% confidence interval (CI), 1.02-1.39] and the HR from prospective analysis (HRP) was 1.36 (95% CI, 0.99-1.87). For BRCA2 mutation carriers, smoking for more than 5 years before an FFTP showed an association of a similar magnitude, but the confidence limits were wider (HRR = 1.25; 95% CI, 1.01-1.55 and HRP = 1.30; 95% CI, 0.83-2.01). For both carrier groups, alcohol consumption was not associated with breast cancer risk.

CONCLUSIONS

The finding that smoking during the prereproductive years increases breast cancer risk for mutation carriers warrants further investigation.

IMPACT

This is the largest prospective study of BRCA mutation carriers to assess these important risk factors.

Risk-reducing salpingo-oophorectomy, natural menopause, and breast cancer risk: an international prospective cohort of BRCA1 and BRCA2 mutation carriers

BACKGROUND

The effect of risk-reducing salpingo-oophorectomy (RRSO) on breast cancer risk for BRCA1 and BRCA2 mutation carriers is uncertain. Retrospective analyses have suggested a protective effect but may be substantially biased. Prospective studies have had limited power, particularly for BRCA2 mutation carriers. Further, previous studies have not considered the effect of RRSO in the context of natural menopause.

METHODS

A multi-centre prospective cohort of 2272 BRCA1 and 1605 BRCA2 mutation carriers was followed for a mean of 5.4 and 4.9 years, respectively; 426 women developed incident breast cancer. RRSO was modelled as a time-dependent covariate in Cox regression, and its effect assessed in premenopausal and postmenopausal women.

RESULTS

There was no association between RRSO and breast cancer for BRCA1 (HR = 1.23; 95% CI 0.94-1.61) or BRCA2 (HR = 0.88; 95% CI 0.62-1.24) mutation carriers. For BRCA2 mutation carriers, HRs were 0.68 (95% CI 0.40-1.15) and 1.07 (95% CI 0.69-1.64) for RRSO carried out before or after age 45 years, respectively. The HR for BRCA2 mutation carriers decreased with increasing time since RRSO (HR = 0.51; 95% CI 0.26-0.99 for 5 years or longer after RRSO). Estimates for premenopausal women were similar.

CONCLUSION

We found no evidence that RRSO reduces breast cancer risk for BRCA1 mutation carriers. A potentially beneficial effect for BRCA2 mutation carriers was observed, particularly after 5 years following RRSO. These results may inform counselling and management of carriers with respect to RRSO.

Recreational Physical Activity Is Associated with Reduced Breast Cancer Risk in Adult Women at High Risk for Breast Cancer: A Cohort Study of Women Selected for Familial and Genetic Risk

Although physical activity is associated with lower breast cancer risk for average-risk women, it is not known if this association applies to women at high familial/genetic risk. We examined the association of recreational physical activity (self-reported by questionnaire) with breast cancer risk using the Prospective Family Study Cohort, which is enriched with women who have a breast cancer family history (N = 15,550). We examined associations of adult and adolescent recreational physical activity (quintiles of age-adjusted total metabolic equivalents per week) with breast cancer risk using multivariable Cox proportional hazards regression, adjusted for demographics, lifestyle factors, and body mass index. We tested for multiplicative interactions of physical activity with predicted absolute breast cancer familial risk based on pedigree data and with BRCA1 and BRCA2 mutation status. Baseline recreational physical activity level in the highest four quintiles compared with the lowest quintile was associated with a 20% lower breast cancer risk (HR, 0.80; 95% confidence interval, 0.68-0.93). The association was not modified by familial risk or BRCA mutation status (P interactions >0.05). No overall association was found for adolescent recreational physical activity. Recreational physical activity in adulthood may lower breast cancer risk for women across the spectrum of familial risk. SIGNIFICANCE: These findings suggest that physical activity might reduce breast cancer risk by about 20% for women across the risk continuum, including women at higher-than-average risk due to their family history or genetic susceptibility.See related commentary by Niehoff et al., p. 23.

Accuracy of Risk Estimates from the iPrevent Breast Cancer Risk Assessment and Management Tool

BACKGROUND

iPrevent is an online breast cancer (BC) risk management decision support tool. It uses an internal switching algorithm, based on a woman's risk factor data, to estimate her absolute BC risk using either the International Breast Cancer Intervention Study (IBIS) version 7.02, or Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm version 3 models, and then provides tailored risk management information. This study assessed the accuracy of the 10-year risk estimates using prospective data.

METHODS

iPrevent-assigned 10-year invasive BC risk was calculated for 15 732 women aged 20-70 years and without BC at recruitment to the Prospective Family Study Cohort. Calibration, the ratio of the expected (E) number of BCs to the observed (O) number and discriminatory accuracy were assessed.

RESULTS

During the 10 years of follow-up, 619 women (3.9%) developed BC compared with 702 expected (E/O = 1.13; 95% confidence interval [CI] =1.05 to 1.23). For women younger than 50 years, 50 years and older, and BRCA1/2-mutation carriers and noncarriers, E/O was 1.04 (95% CI = 0.93 to 1.16), 1.24 (95% CI = 1.11 to 1.39), 1.13 (95% CI = 0.96 to 1.34), and 1.13 (95% CI = 1.04 to 1.24), respectively. The C-statistic was 0.70 (95% CI = 0.68 to 0.73) overall and 0.74 (95% CI = 0.71 to 0.77), 0.63 (95% CI = 0.59 to 0.66), 0.59 (95% CI = 0.53 to 0.64), and 0.65 (95% CI = 0.63 to 0.68), respectively, for the subgroups above. Applying the newer IBIS version 8.0b in the iPrevent switching algorithm improved calibration overall (E/O = 1.06, 95% CI = 0.98 to 1.15) and in all subgroups, without changing discriminatory accuracy.

CONCLUSIONS

For 10-year BC risk, iPrevent had good discriminatory accuracy overall and was well calibrated for women aged younger than 50 years. Calibration may be improved in the future by incorporating IBIS version 8.0b.

Alcohol consumption, cigarette smoking, and familial breast cancer risk: findings from the Prospective Family Study Cohort (ProF-SC)

Background

Alcohol consumption and cigarette smoking are associated with an increased risk of breast cancer (BC), but it is unclear whether these associations vary by a woman’s familial BC risk.

Methods

Using the Prospective Family Study Cohort, we evaluated associations between alcohol consumption, cigarette smoking, and BC risk. We used multivariable Cox proportional hazard models to estimate hazard ratios (HR) and 95% confidence intervals (CI). We examined whether associations were modified by familial risk profile (FRP), defined as the 1-year incidence of BC predicted by Breast Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA), a pedigree-based algorithm.

Results

We observed 1009 incident BC cases in 17,435 women during a median follow-up of 10.4 years. We found no overall association of smoking or alcohol consumption with BC risk (current smokers compared with never smokers HR 1.02, 95% CI 0.85–1.23; consuming ≥ 7 drinks/week compared with non-regular drinkers HR 1.10, 95% CI 0.92–1.32), but we did observe differences in associations based on FRP and by estrogen receptor (ER) status. Women with lower FRP had an increased risk of ER-positive BC associated with consuming ≥ 7 drinks/week (compared to non-regular drinkers), whereas there was no association for women with higher FRP. For example, women at the 10th percentile of FRP (5-year BOADICEA = 0.15%) had an estimated HR of 1.46 (95% CI 1.07–1.99), whereas there was no association for women at the 90th percentile (5-year BOADICEA = 4.2%) (HR 1.07, 95% CI 0.80–1.44). While the associations with smoking were not modified by FRP, we observed a positive multiplicative interaction by FRP (p_interaction = 0.01) for smoking status in women who also consumed alcohol, but not in women who were non-regular drinkers.

Conclusions

Moderate alcohol intake was associated with increased BC risk, particularly for women with ER-positive BC, but only for those at lower predicted familial BC risk (5-year BOADICEA < 1.25). For women with a high FRP (5-year BOADICEA ≥ 6.5%) who also consumed alcohol, being a current smoker was associated with increased BC risk.

Benign breast disease increases breast cancer risk independent of underlying familial risk profile: Findings from a Prospective Family Study Cohort

Benign breast disease (BBD) is an established breast cancer (BC) risk factor, but it is unclear whether the magnitude of the association applies to women at familial or genetic risk. This information is needed to improve BC risk assessment in clinical settings. Using the Prospective Family Study Cohort, we used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of BBD with BC risk. We also examined whether the association with BBD differed by underlying familial risk profile (FRP), calculated using absolute risk estimates from the Breast Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) model. During 176,756 person-years of follow-up (median: 10.9 years, maximum: 23.7) of 17,154 women unaffected with BC at baseline, we observed 968 incident cases of BC. A total of 4,704 (27%) women reported a history of BBD diagnosis at baseline. A history of BBD was associated with a greater risk of BC: HR = 1.31 (95% CI: 1.14-1.50), and did not differ by underlying FRP, with HRs of 1.35 (95% CI: 1.11-1.65), 1.26 (95% CI: 1.00-1.60), and 1.40 (95% CI: 1.01-1.93), for categories of full-lifetime BOADICEA score <20%, 20 to <35%, ≥35%, respectively. There was no difference in the association for women with BRCA1 mutations (HR: 1.64; 95% CI: 1.04-2.58), women with BRCA2 mutations (HR: 1.34; 95% CI: 0.78-2.3) or for women without a known BRCA1 or BRCA2 mutation (HR: 1.31; 95% CI: 1.13-1.53) (p_interaction  = 0.95). Women with a history of BBD have an increased risk of BC that is independent of, and multiplies, their underlying familial and genetic risk.

The Influence of Number and Timing of Pregnancies on Breast Cancer Risk for Women With BRCA1 or BRCA2 Mutations

BACKGROUND

Full-term pregnancy (FTP) is associated with a reduced breast cancer (BC) risk over time, but women are at increased BC risk in the immediate years following an FTP. No large prospective studies, however, have examined whether the number and timing of pregnancies are associated with BC risk for BRCA1 and BRCA2 mutation carriers.

METHODS

Using weighted and time-varying Cox proportional hazards models, we investigated whether reproductive events are associated with BC risk for mutation carriers using a retrospective cohort (5707 BRCA1 and 3525 BRCA2 mutation carriers) and a prospective cohort (2276 BRCA1 and 1610 BRCA2 mutation carriers), separately for each cohort and the combined prospective and retrospective cohort.

RESULTS

For BRCA1 mutation carriers, there was no overall association with parity compared with nulliparity (combined hazard ratio [HRc] = 0.99, 95% confidence interval [CI] = 0.83 to 1.18). Relative to being uniparous, an increased number of FTPs was associated with decreased BC risk (HRc = 0.79, 95% CI = 0.69 to 0.91; HRc = 0.70, 95% CI = 0.59 to 0.82; HRc = 0.50, 95% CI = 0.40 to 0.63, for 2, 3, and ≥4 FTPs, respectively, P trend < .0001) and increasing duration of breastfeeding was associated with decreased BC risk (combined cohort P trend = .0003). Relative to being nulliparous, uniparous BRCA1 mutation carriers were at increased BC risk in the prospective analysis (prospective hazard ration [HRp] = 1.69, 95% CI = 1.09 to 2.62). For BRCA2 mutation carriers, being parous was associated with a 30% increase in BC risk (HRc = 1.33, 95% CI = 1.05 to 1.69), and there was no apparent decrease in risk associated with multiparity except for having at least 4 FTPs vs. 1 FTP (HRc = 0.72, 95% CI = 0.54 to 0.98).

CONCLUSIONS

These findings suggest differential associations with parity between BRCA1 and BRCA2 mutation carriers with higher risk for uniparous BRCA1 carriers and parous BRCA2 carriers.

Age-specific breast cancer risk by body mass index and familial risk: prospective family study cohort (ProF-SC)

BACKGROUND

The association between body mass index (BMI) and risk of breast cancer depends on time of life, but it is unknown whether this association depends on a woman's familial risk.

METHODS

We conducted a prospective study of a cohort enriched for familial risk consisting of 16,035 women from 6701 families in the Breast Cancer Family Registry and the Kathleen Cunningham Foundation Consortium for Research into Familial Breast Cancer followed for up to 20 years (mean 10.5 years). There were 896 incident breast cancers (mean age at diagnosis 55.7 years). We used Cox regression to model BMI risk associations as a function of menopausal status, age, and underlying familial risk based on pedigree data using the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA), all measured at baseline.

RESULTS

The strength and direction of the BMI risk association depended on baseline menopausal status (P < 0.001); after adjusting for menopausal status, the association did not depend on age at baseline (P = 0.6). In terms of absolute risk, the negative association with BMI for premenopausal women has a much smaller influence than the positive association with BMI for postmenopausal women. Women at higher familial risk have a much larger difference in absolute risk depending on their BMI than women at lower familial risk.

CONCLUSIONS

The greater a woman's familial risk, the greater the influence of BMI on her absolute postmenopausal breast cancer risk. Given that age-adjusted BMI is correlated across adulthood, maintaining a healthy weight throughout adult life is particularly important for women with a family history of breast cancer.

Does stress increase risk of breast cancer? A 15-year prospective study

OBJECTIVE

The possible impact of stress on cancer incidence remains controversial. We prospectively evaluated associations between life event stressors, social support, personality characteristics (optimism, anger control, antiemotionality), and risk of developing primary breast cancer (BCa), in women at increased familial risk of BCa.

METHODS

A prospective cohort, repeated measures design was used. Recruitment was through the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer, which collects genetic, epidemiological, and clinical data from Australasian families with multiple BCa cases. Acute and chronic stressors for the prior 3 years and psychosocial, clinical, and epidemiological variables were measured at cohort entry and at 3-yearly intervals. Cox proportional hazard regression analysis controlling for BCa risk factors and familial clustering was undertaken. The primary outcome was histopathologically confirmed BCa (invasive or ductal carcinoma in situ, including occult cases diagnosed during risk-reducing mastectomy).

RESULTS

Of 3595 consecutive women invited to participate, 3054 (85.0%) consented. Of these, 2739 (89.7%) from 990 families (range 1-16 per family) completed at least 1 assessment point. During the study, 103 women were diagnosed with BCa. No stressor or psychosocial variable or interaction between them was significantly associated with BCa in unadjusted or adjusted models (total acute stressors HR = 1.03 [0.99-1.08], P = .19; total chronic stressors HR = 1.0 [0.90-1.11], P = .98).

CONCLUSIONS

This study did not demonstrate an association between acute and chronic stressors, social support, optimism, antiemotionality or anger control, and BCa risk. Women should focus on proven methods of BCa risk reduction.

Oral Contraceptive Use and Breast Cancer Risk: Retrospective and Prospective Analyses From a BRCA1 and BRCA2 Mutation Carrier Cohort Study

BACKGROUND

For BRCA1 and BRCA2 mutation carriers, the association between oral contraceptive preparation (OCP) use and breast cancer (BC) risk is still unclear.

METHODS

Breast camcer risk associations were estimated from OCP data on 6030 BRCA1 and 3809 BRCA2 mutation carriers using age-dependent Cox regression, stratified by study and birth cohort. Prospective, left-truncated retrospective and full-cohort retrospective analyses were performed.

RESULTS

For BRCA1 mutation carriers, OCP use was not associated with BC risk in prospective analyses (hazard ratio [HR] = 1.08, 95% confidence interval [CI] = 0.75 to 1.56), but in the left-truncated and full-cohort retrospective analyses, risks were increased by 26% (95% CI = 6% to 51%) and 39% (95% CI = 23% to 58%), respectively. For BRCA2 mutation carriers, OCP use was associated with BC risk in prospective analyses (HR = 1.75, 95% CI = 1.03 to 2.97), but retrospective analyses were inconsistent (left-truncated: HR = 1.06, 95% CI = 0.85 to 1.33; full cohort: HR = 1.52, 95% CI = 1.28 to 1.81). There was evidence of increasing risk with duration of use, especially before the first full-term pregnancy (BRCA1: both retrospective analyses, P < .001 and P = .001, respectively; BRCA2: full retrospective analysis, P = .002).

CONCLUSIONS

Prospective analyses did not show that past use of OCP is associated with an increased BC risk for BRCA1 mutation carriers in young middle-aged women (40-50 years). For BRCA2 mutation carriers, a causal association is also not likely at those ages. Findings between retrospective and prospective analyses were inconsistent and could be due to survival bias or a true association for younger women who were underrepresented in the prospective cohort. Given the uncertain safety of long-term OCP use for BRCA1/2 mutation carriers, indications other than contraception should be avoided and nonhormonal contraceptive methods should be discussed.

Testing for Gene-Environment Interactions Using a Prospective Family Cohort Design: Body Mass Index in Early and Later Adulthood and Risk of Breast Cancer

The ability to classify people according to their underlying genetic susceptibility to a disease is increasing with new knowledge, better family data, and more sophisticated risk prediction models, allowing for more effective prevention and screening. To do so, however, we need to know whether risk associations are the same for people with different genetic susceptibilities. To illustrate one way to estimate such gene-environment interactions, we used prospective data from 3 Australian family cancer cohort studies, 2 enriched for familial risk of breast cancer. There were 288 incident breast cancers in 9,126 participants from 3,222 families. We used Cox proportional hazards models to investigate whether associations of breast cancer with body mass index (BMI; weight (kg)/height (m)2) at age 18-21 years, BMI at baseline, and change in BMI differed according to genetic risk based on lifetime breast cancer risk from birth, as estimated by BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) software, adjusted for age at baseline data collection. Although no interactions were statistically significant, we have demonstrated the power with which gene-environment interactions can be investigated using a cohort enriched for persons with increased genetic risk and a continuous measure of genetic risk based on family history.

Improved quality of risk-reducing salpingo-oophorectomy in Australasian women at high risk of pelvic serous cancer

Objectives

The quality of risk-reducing salpingo-oophorectomy (RRSO) performed in Australasian women was previously reported to be suboptimal. Here we describe the quality of RRSO performed since 2008 in women enrolled in the same cohort and determine whether it has improved.

Design

Prospective cohort study of women at high risk of pelvic serous cancer (PSC) in kConFab. Eligible women had RRSO between 2008 and 2014 and their RRSO surgical and pathology reports were reviewed. “Adequate” surgery and pathology were defined as complete removal and paraffin embedding of all ovarian and extra-uterine fallopian tube tissue, respectively. Associations between clinical factors and “adequate” pathology were assessed using logistic regression. Data were compared with published cohort data on RRSO performed prior to 2008 using Chi square test.

Results

Of 164 contemporary RRSOs performed in 78 centres, 158/159 (99%) had “adequate” surgery and 108/164 (66%) had “adequate” pathology. Surgery performed by a gynaecologic oncologist rather than a general gynaecologist [OR 8.2, 95%CI (3.6–20.4), p < 0.001], surgery without concurrent hysterectomy [OR 2.5, 95%CI (1.1–6.0), p = 0.03], more recent year of surgery [OR 1.4, 95%CI (1.1–1.8), p = 0.02], and clinical notation that indicated high risk [OR 19.4, 95%CI (3.1–385), p = 0.008] were independently associated with “adequate” pathology. Both surgery and pathology were significantly more likely to be “adequate” (p < 0.001) in this contemporary sample.

Conclusion

The quality of RRSOs has significantly improved since our last report. Surgery by a gynaecologic oncologist who informs the pathologist that the woman is at high risk for PSC is associated with optimal RRSO pathology.

Anti-Müllerian hormone serum concentrations of women with germline BRCA1 or BRCA2 mutations

STUDY QUESTION

Do women with BRCA1 or BRCA2 mutations have reduced ovarian reserve, as measured by circulating anti-Müllerian hormone (AMH) concentration?

SUMMARY ANSWER

Women with a germline mutation in BRCA1 have reduced ovarian reserve as measured by AMH.

WHAT IS KNOWN ALREADY

The DNA repair enzymes encoded by BRCA1 and BRCA2 are implicated in reproductive aging. Circulating AMH is a biomarker of ovarian reserve and hence reproductive lifespan.

STUDY DESIGN, SIZE, DURATION

This was a cross-sectional study of AMH concentrations of 693 women at the time of enrolment into the Kathleen Cuningham Foundation Consortium for research in the Familial Breast Cancer (kConFab) cohort study (recruitment from 19 August 1997 until 18 September 2012). AMH was measured on stored plasma samples between November 2014 and January 2015 using an electrochemiluminescence immunoassay platform.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible women were from families segregating BRCA1 or BRCA2 mutations and had known mutation status. Participants were aged 25–45 years, had no personal history of cancer, retained both ovaries and were not pregnant or breastfeeding at the time of plasma storage. Circulating AMH was measured for 172 carriers and 216 non-carriers from families carrying BRCA1 mutations, and 147 carriers and 158 non-carriers from families carrying BRCA2 mutations. Associations between plasma AMH concentration and carrier status were tested by linear regression, adjusted for age at plasma storage, oral contraceptive use, body mass index and cigarette smoking.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean AMH concentration was negatively associated with age (P < 0.001). Mutation carriers were younger at blood draw than non-carriers (P ≤ 0.031). BRCA1 mutation carriers had, on average, 25% (95% CI: 5%–41%, P = 0.02) lower AMH concentrations than non-carriers and were more likely to have AMH concentrations in the lowest quartile for age (OR 1.84, 95% CI: 1.11–303, P = 0.02). There was no evidence of an association between AMH concentration and BRCA2 mutation status (P = 0.94).

LIMITATIONS, REASONS FOR CAUTION

AMH does not directly measure the primordial follicle pool. The clinical implications of the lower AMH concentrations seen in BRCA1 mutation carriers cannot be assessed by this study design.

WIDER IMPLICATIONS OF THE FINDINGS

Women with a germline mutation in BRCA1 may have reduced ovarian reserve. This is consistent with other smaller studies in the literature and has potential implications for fertility and reproductive lifespan.

STUDY FUNDING/COMPETING INTEREST(S)

kConFab is supported by a grant from the Australian National Breast Cancer Foundation, and previously by the National Health and Medical Research Council (NHMRC), the Queensland Cancer Fund, the Cancer Councils of New South Wales, Victoria, Tasmania and South Australia, and the Cancer Foundation of Western Australia. K.A.P. is an Australian National Breast Cancer Foundation Practitioner Fellow. J.L.H. is a NHMRC Senior Principal Research Fellow. M.H. is a NHMRC Practitioner Fellow. R.A.A. reports personal fees from Roche Diagnostics & Beckman Coulter outside the submitted work and C.S. reports other earnings from Melbourne IVF outside the submitted work. The remaining authors have nothing to declare and no conflicts of interest.

Breast cancer risk prediction using a polygenic risk score in the familial setting: a prospective study from the Breast Cancer Family Registry and kConFab

PURPOSE

This study examined the utility of sets of single-nucleotide polymorphisms (SNPs) in familial but non-BRCA-associated breast cancer (BC).

METHODS

We derived a polygenic risk score (PRS) based on 24 known BC risk SNPs for 4,365 women from the Breast Cancer Family Registry and Kathleen Cuningham Consortium Foundation for Research into Familial Breast Cancer familial BC cohorts. We compared scores for women based on cancer status at baseline; 2,599 women unaffected at enrollment were followed-up for an average of 7.4 years. Cox proportional hazards regression was used to analyze the association of PRS with BC risk. The BOADICEA risk prediction algorithm was used to measure risk based on family history alone.

RESULTS

The mean PRS at baseline was 2.25 (SD, 0.35) for affected women and was 2.17 (SD, 0.35) for unaffected women from combined cohorts (P < 10-6). During follow-up, 205 BC cases occurred. The hazard ratios for continuous PRS (per SD) and upper versus lower quintiles were 1.38 (95% confidence interval: 1.22-1.56) and 3.18 (95% confidence interval: 1.84-5.23) respectively. Based on their PRS-based predicted risk, management for up to 23% of women could be altered.

CONCLUSION

Including BC-associated SNPs in risk assessment can provide more accurate risk prediction than family history alone and can influence recommendations for cancer screening and prevention modalities for high-risk women.Genet Med 19 1, 30-35.

Modifiers of breast and ovarian cancer risks for BRCA1 and BRCA2 mutation carriers

Pathogenic mutations in BRCA1 and BRCA2 are associated with high risks of breast and ovarian cancer. However, penetrance estimates for mutation carriers have been found to vary substantially between studies, and the observed differences in risk are consistent with the hypothesis that genetic and environmental factors modify cancer risks for women with these mutations. Direct evidence that this is the case has emerged in the past decade, through large-scale international collaborative efforts. Here, we describe the methodological challenges in the identification and characterisation of these risk-modifying factors, review the latest evidence on genetic and lifestyle/hormonal risk factors that modify breast and ovarian cancer risks for women with BRCA1 and BRCA2 mutations and outline the implications of these findings for cancer risk prediction. We also review the unresolved issues in this area of research and identify strategies of clinical implementation so that women with BRCA1 and BRCA2 mutations are no longer counselled on the basis of 'average' risk estimates.

Long-term outcomes of risk-reducing surgery in unaffected women at increased familial risk of breast and/or ovarian cancer

This study prospectively investigated long-term psychosocial outcomes for women who opted for risk-reducing mastectomy (RRM) and/or risk-reducing salpingo-oophorectomy (RRSO). Unaffected women from high-risk breast cancer families who had completed baseline questionnaires for an existing study and subsequently underwent RRM and/or RRSO, completed measures of perceived breast and ovarian cancer risk, anxiety, depression, cancer-related anxiety, body image, sexual functioning, menopausal symptoms, use of hormone replacement therapy and decision regret 3 years post-surgery. Outcomes were compared to age- and risk-matched controls. Participants (N = 233) were 17 women who had RRM (39 controls), 38 women who had RRSO (94 controls) and 15 women who had RRM + RRSO (30 controls). Women who underwent RRM and those who underwent RRM + RRSO reported reductions in perceived breast cancer risk and perceived breast and ovarian cancer risk respectively, compared to their respective controls. RRM women reported greater reductions in cancer-related anxiety compared with both controls and RRSO women. RRSO women reported more sexual discomfort than controls and more urogenital menopausal symptoms than controls and RRM only women. No differences in general anxiety, depression or body image were observed. Regret was associated with greater reductions in body image since surgery and more sexual discomfort, although overall regret levels were low. Women who undergo RRM experience psychological benefits associated with reduced breast cancer risk. Although women who undergo RRSO experience some deterioration in sexual and menopausal symptoms, they do not regret their surgery decision. It is vital that women considering these procedures receive detailed information about potential psychosocial consequences.

Intuition versus cognition: a qualitative exploration of how women understand and manage their increased breast cancer risk

Risk comprehension in individuals at increased familial risk of cancer is suboptimal and little is known about how risk is understood and managed by at-risk individuals who do not undergo genetic testing. We qualitatively studied these issues in 36 unaffected women from high-risk breast cancer families, including both women who had and had not undergone genetic testing. Data were collected through semi-structured interviews and data analysis was guided by Grounded Theory. Risk comprehension and risk management were largely influenced by the individual's experience of coming from a high-risk family, with both tested and untested women relying heavily on their intuition. Although women's cognitive understanding of their risk appeared generally accurate, this objective risk information was considered of secondary value. The findings could be used to guide the development and delivery of information about risk and risk management to genetically tested and untested individuals at increased risk of hereditary cancer.

Facilitators and Challenges in Psychosocial Adaptation to Being at Increased Familial Risk of Breast Cancer

Little is known about the process of psychosocial adaptation to familial risk in tested and untested individuals at increased familial risk of cancer. This paper presents findings from a qualitative study of 36 women participating in the Kathleen Cuningham Consortium for Research into Familial Breast cancer (kConFab) Psychosocial study. Facilitators and challenges in psychosocial adaptation were identified through semi-structured interviews. The women, who were either tested (carriers or non-carriers of breast cancer susceptibility mutations) or untested (ineligible for testing or eligible but delayed or declined testing), described personal, support network and healthcare characteristics that impacted on the adaptation process. Challenges in one domain could be overcome by facilitators in other domains and key differences relating to whether women had undergone testing, or not, were identified. Tested and untested women with an increased familial risk of breast cancer may benefit from support tailored to their mutation testing status in order to enhance adaptation.

Misperceptions of ovarian cancer risk in women at increased risk for hereditary ovarian cancer

This study assessed the sociodemographic, medical and psychological predictors of accuracy of perceived risk in women at increased genetic risk for ovarian cancer. Women participating in a large cohort study who were at increased risk of ovarian and fallopian tube cancer, had no personal history of cancer and had ≥1 ovary in situ at cohort enrollment, were eligible. Women completed self-administered questionnaires and attended an interview at enrollment. Of 2,868 women unaffected with cancer at cohort enrollment, 561 were eligible. 335 women (59.8 %) overestimated their ovarian cancer risk, while 215 women (38.4 %) accurately estimated their risk, and 10 (1.8 %) underestimated it. Women who did not know their mutation status were more likely to overestimate their risk (OR 1.74, 95 % CI 1.10, 2.77, p = 0.018), as were those with higher cancer-specific anxiety (OR 1.05, 95 % CI 1.02, 1.08, p < 0.001) and/or a mother who had been diagnosed with ovarian cancer (OR 1.98, 95 % CI 1.23, 3.18, p = 0.005). Amongst the group of women who did not know their mutation status, 63.3 % overestimated their risk and the mean perceived lifetime risk of developing ovarian cancer was 42.1 %, compared to a mean objective risk of 6.4 %. A large number of women at increased risk for ovarian cancer overestimate their risk. This is of concern especially in women who are at moderately increased risk only; for this sub-group of women, interventions are needed to reduce potentially unnecessary psychological distress and minimise engagement in unnecessary surgery or screening.

Factors associated with dropout in a lung cancer high‑risk cohort--the Liverpool lung project

In long-term longitudinal cohort studies the dropout of participants occurring as a result of withdrawal or lost to follow-up may have greater impact on the effect estimates, if characteristics of participants who drop out and those still active in the study differ significantly. The study aimed to investigate factors associated with dropout in a 5-year follow-up of individuals at 'high‑risk' of lung cancer. We studied 'high‑risk' group of 1,486 individuals aged 45-79 selected from the Liverpool Lung Prospective (LLP) cohort study using a strategy reflecting only age, smoking duration and history of pulmonary disease. Study subjects were recalled annually from 2005-2009 for follow-up collection of specimens and questionnaire data. The dropout rate over the follow-up time was investigated using the Kaplan‑Meier survival curve and the Cox proportional hazard model. Dropout rate was 31% after an average of 3 annual visits. Female gender hazard ratio (HR) 1.35 (95% CI 1.09-1.66), current smoking 1.26 (1.02-1.57), prior diagnosis of malignant disease 0.54 (0.36-0.79), home visits 0.67 (0.48-0.94) and systolic blood pressure 1.46 (1.10-1.94) were significantly associated with the dropout rate. Nearly 40% of individuals selected into the 'high‑risk' group by the old criteria were low risk with predicted 5-year absolute risk of less than 2.5%. In conclusion, follow-up of individuals is feasible within the LLP, but may be prone to selective withdrawal attributable to patient's state of health and mobility. We recommend future design of 'high‑risk' follow‑up studies to consider home visit as a useful strategy to encourage continued participation.

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.

Looking different, feeling different: women's reactions to risk-reducing breast and ovarian surgery

Most studies of quality of life following risk-reducing bilateral salpingo-oophorectomy (RRSO) and mastectomy (RRM) for inherited breast and ovarian cancer susceptibility were conducted before counseling protocols were established and included women at varying times since surgery. This study aimed to overcome these deficiencies and to provide current data on outcomes for this growing group of women. Semi-structured interviews were used to explore the experiences of an Australian cohort of 40 high-risk women 3 years after they underwent RRM and/or RRSO. Data were analyzed using the method of constant comparison. 19/40 women underwent RRSO, 8/40 RRM and 13/40 both procedures. Two themes-looking different and feeling different-captured the psychosocial impact of surgery upon interviewees. All regarded RR surgery as a positive experience and were relieved at having their risks of cancer substantially reduced; however, reducing risk by removing these body parts is not without costs. In addition to relief interviewees also reported experiencing a range of negative emotions and a range of unexpected bodily sensations following surgery and reflected upon both positive and negative changes in their appearance. Women said they had been unprepared for the lack of sensation in reconstructed breasts and/or the severity of menopausal symptoms, which often had a negative impact upon sexuality. At-risk women regard RR surgery as a positive way to manage cancer risk. However, although women who currently undergo RR surgery are informed about its sequelae, few are entirely prepared for the reality of undergoing this procedure. We recommend that women who undergo these procedures should be provided with information supported by psychosocial input before and after RR surgery.

Adequacy of risk-reducing gynaecologic surgery in BRCA1 or BRCA2 mutation carriers and other women at high risk of pelvic serous cancer

The aim of this study was to describe the type of risk-reducing gynaecologic surgery (RRGS) and the extent of pathological evaluation being undertaken for Australasian women at high familial risk of pelvic serous cancer. Surgical and pathology reports were reviewed for women with BRCA1/BRCA2 mutations, or a family history of breast and ovarian cancer, who underwent RRGS between 1998 and 2008. "Adequate" surgery was defined as complete removal of all ovarian and extra-uterine fallopian tube tissue. "Adequate" pathology was defined as paraffin embedding of all removed ovarian and tubal tissue. Predictors of adequacy were assessed using logistic regression. There were 201 women, including 173 mutation carriers, who underwent RRGS. Of these, 91% had adequate surgery and 23% had adequate pathology. Independent predictors of adequate surgery were surgeon type (OR = 20; 95% CI 2-167; P = 0.005 for gynaecologic oncologists versus general gynaecologists), more recent surgery (OR = 1.33/year; 95% CI 1.07-1.67; P = 0.012) and younger patient age (OR = 0.93/year of age; 95% CI 0.87-0.99; P = 0.028). Independent predictors of adequate pathology were more recent surgery (OR = 1.26/year; 95% CI 1.06-1.49; P = 0.008) and surgeon type (OR = 3.1; 95% CI 1.4-6.7; P = 0.004 for gynaecologic oncologists versus general gynaecologists). Four serous ovarian cancers and one endometrioid endometrial cancer were detected during surgery or pathological examination. In conclusion Australasian women attending a specialist gynaecologic oncologist for RRGS are most likely to have adequate surgery and pathological examination. Additional education of clinicians and consumers is needed to ensure optimal surgery and pathology in these women.

Prospective study of breast cancer risk for mutation negative women from BRCA1 or BRCA2 mutation positive families

Published studies have reached contradictory conclusions regarding breast cancer risk for women from families segregating a BRCA1 or BRCA2 mutation who do not carry the family-specific mutation. Accurate estimation of breast cancer risk is crucial for appropriate counselling regarding risk management. The aim of this study is to prospectively assess whether breast cancer risk for mutation negative women from families segregating BRCA1 or BRCA2 mutations is greater than for women in the general population. Eligible women were 722 first-, second- and third-degree relatives of a BRCA1 or BRCA2 mutation carrier from 224 mutation positive (128 BRCA1, 96 BRCA2) families, had no personal cancer history at baseline, and had been tested and found not to carry the family-specific mutation. Self-reported family history of cancer, preventive interventions and verified cancer diagnoses were collected at baseline, and every 3 years thereafter. Median follow-up was 6.1 years (range 0.1-12.4 years). Time at risk of breast cancer was censored at cancer diagnosis or risk-reducing surgery. Standardised incidence ratios (SIR) were estimated by comparing observed to population incidences of invasive breast cancer using Australian Cancer Incidence and Mortality Books. Six cases of invasive breast cancer were observed. The estimated SIRs were 1.14 (95% CI: 0.51-2.53) overall (n = 722), 1.29 (95% CI: 0.58-2.88) when restricted to first- and second-degree relatives of an affected mutation carrier (n = 442) and 0.48 (95% CI: 0.12-1.93) when restricted to those with no family history of breast cancer in the non-mutation carrying parental lineage (n = 424). There was no evidence that mutation negative women from families segregating BRCA1 or BRCA2 mutations are at increased risk of breast cancer. Despite this being the largest prospective cohort to assess this issue, moderately increased breast cancer risk (2-fold) cannot be ruled out.

Predictors of breast cancer screening behavior in women with a strong family history of the disease

This study applied the self-regulation model to examine cognitive and emotional predictors of screening in unaffected women with a strong family history of breast cancer. 748 unaffected female members of an Australian registry of multiple-case breast cancer families formed the sample. Participants completed a baseline psychosocial questionnaire and a screening questionnaire 3 years later. Multinomial logistic regression was employed to determine predictors of under- and over-screening according to national guidelines. At follow-up 16% of women under-screened and 10% over-screened with mammography; 55% under-screened with clinical breast examination (CBE); and 9% over-screened with breast self-examination (BSE). Of the women found screening according to guidelines for mammography 72% reported ever having received specific recommendations for mammography screening from a health professional. Compared to appropriate screeners, under-screeners on mammography were less likely to have received a screening recommendation (as were under-screeners on CBE), were younger and reported lower perceived breast cancer risk, but were at higher relative risk (RR) of breast cancer and were more likely to report elevated depression. Over-screeners on mammography were more likely to be younger and have a lower RR of breast cancer. Over-screeners on BSE reported elevated cancer-specific anxiety, were less likely to be university educated and more likely to have received a recommendation for BSE. Under- and over-screening is common in women with a strong family history of breast cancer. Evaluation of interventions targeting perceived risk of breast cancer, anxiety and depression are needed to ensure women obtain accurate advice from relevant specialists and enact screening recommendations.

Misconceptions about breast lumps and delayed medical presentation in urban breast cancer patients

BACKGROUND

Despite current recommendations for women to be screened for breast cancer with mammography every 1 to 2 years, less than half of all newly diagnosed breast cancers are initially detected through screening mammography. Prompt medical attention to a new breast symptom can result in earlier stage at diagnosis, yet many patients delay seeking medical care after becoming aware of a breast symptom.

METHODS

In a population-based study of breast cancer, we examined factors potentially associated with patient delay in seeking health care for a breast symptom among 436 symptomatic urban breast cancer patients (146 white, 197 black, and 95 Hispanic). Race/ethnicity, socioeconomic status, health care access and utilization, and misconceptions about the meaning of breast lumps were the key independent variables.

RESULTS

Sixteen percent of patients reported delaying more than 3 months before seeking medical advice about breast symptoms. Misconceptions about breast lumps and lacking a regular provider, health insurance, and recent preventive care were all associated with prolonged patient delay (P < 0.005 for all). Misconceptions were much more common among ethnic minorities and women of lower socioeconomic status.

CONCLUSION

Reducing patient delay and disparities in delay will require educating women about the importance of getting breast lumps evaluated in a timely manner and providing greater access to regular health care.

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.

Prostate screening uptake in Australian BRCA1 and BRCA2 carriers

Men who carry mutations in BRCA1 or BRCA2 are at increased risk for prostate cancer. However the efficacy of prostate screening in this setting is uncertain and limited data exists on the uptake of prostate screening by mutation carriers. This study prospectively evaluated uptake of prostate cancer screening in a multi-institutional cohort of mutation carriers. Subjects were unaffected male BRCA1 and BRCA2 mutation carriers, aged 40–69 years, enrolled in the Kathleen Cuningham Consortium for Research into Familial Breast Cancer (kConFab) and who had completed a mailed, self-report follow-up questionnaire 3 yearly after study entry. Of the 75 male carriers in this study, only 26 (35%) had elected to receive their mutation result. Overall, 51 (68%) did not recall having received a recommendation to have prostate screening because of their family history, but 41 (55%) had undergone a prostate specific antigen (PSA) test and 32 (43%) a digital rectal examination (DRE) in the previous 3 years. Those who were aware of their mutation result were more likely to have received a recommendation for prostate screening (43 vs. 6%, p = 0.0001), and to have had a PSA test (77 vs. 43%, p = 0.005) and a DRE (69 vs. 29%, p = 0.001) in the previous 3 years. The majority of unaffected males enrolled in kConFab with a BRCA1/2 mutation have not sought out their mutation result. However, of those aware of their positive mutation status, most have undergone at least one round of prostate screening in the previous 3 years.

Predictors of cancer worry in unaffected women from high risk breast cancer families: risk perception is not the primary issue

Some women at increased familial risk of breast cancer experience elevated levels of cancer-specific worry, which can possibly act as a barrier to screening, and may be a significant factor in decisions regarding risk-reducing surgery. The aim of this study was to comprehensively examine predictors of cancer-specific worry in high risk women and to test a model which proposes that perceived breast cancer risk mediates the impact of other factors on worry. 1,437 unaffected women from high risk breast cancer families completed questionnaires and interviews. Path analysis was used to test the model of potential predictors of cancer worry, including familial, personal and psychological variables, mediated via perceived cancer risk. Levels of cancer-specific worry were generally low despite an average perceived risk of 50.3%. The goodness-of-fit of the proposed model was poor, explaining only 9% of the variance for perceived risk and 10% of the variance for cancer specific worry. An alternative model of a direct relationship between all of the predictor variables and cancer worry, explained 24% of the variation in cancer worry. General anxiety, perceived risk, the stressful impact of recent cancer related events, a relative risk greater than 10, being closer in age to the youngest breast cancer diagnosis in family, and knowledge of personal mutation status, all independently contributed to cancer worry. Addressing general affective responses, experiences of recent cancer related events, in addition to education about personal risk, should be considered in counselling women with elevated cancer worry. Risk perception appears to act independently of other factors in its formulation and impact on cancer worry. Further research on the way in which women come to perceive their risk is indicated.

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.