Joanne McKinley

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.

A Role for Common Genomic Variants in the Assessment of Familial Breast Cancer

PURPOSE Genome-wide association studies have identified common genomic variants associated with increased susceptibility to breast cancer. In the general population, the risk associated with these known variants seems insufficient to inform clinical management. Their contribution to the development of familial breast cancer is less clear. PATIENTS AND METHODS We studied 1,143 women with breast cancer who had completed BRCA1 and BRCA2 mutation screening as a result of a high risk for hereditary breast cancer. Genotyping of 22 breast cancer-associated genomic variants was performed. A polygenic risk score (PRS), calculated as the sum of the log odds ratios for each allele, was compared with the same metric in 892 controls from the Australian Ovarian Cancer Study. The clinical features associated with the high and low ends of the polygenic risk distribution were compared. RESULTS Women affected by familial breast cancer had a highly significant excess of risk alleles compared with controls (P = 1.0 × 10(-16)). Polygenic risk (measured by the PRS) was greater in women who tested negative for a BRCA1 or BRCA2 mutation compared with mutation carriers (P = 2.3 × 10(-6)). Non-BRCA1/2 women in the top quartile of the polygenic risk distribution were more likely to have had early-onset breast cancer (< 30 years of age, odds ratio [OR]= 3.37, P = .03) and had a higher rate of second breast cancer (OR 1.96, P = .02) compared with women with low polygenic risk. CONCLUSION Genetic testing for common risk variants in women undergoing assessment for familial breast cancer may identify a distinct group of high-risk women in whom the role of risk-reducing interventions should be explored.

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.

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.

Breast Tissue Composition and Immunophenotype and Its Relationship with Mammographic Density in Women at High Risk of Breast Cancer

Aim To investigate the cellular and immunophenotypic basis of mammographic density in women at high risk of breast cancer. Methods Mammograms and targeted breast biopsies were accrued from 24 women at high risk of breast cancer. Mammographic density was classified into Wolfe categories and ranked by increasing density. The histological composition and immunophenotypic profile were quantified from digitized haematoxylin and eosin-stained and immunohistochemically-stained (ERα, ERβ, PgR, HER2, Ki-67, and CD31) slides and correlated to mammographic density. Results Increasing mammographic density was significantly correlated with increased fibrous stroma proportion (rs (22) = 0.5226, p = 0.0088) and significantly inversely associated with adipose tissue proportion (rs (22) = -0.5409, p = 0.0064). Contrary to previous reports, stromal expression of ERα was common (19/20 cases, 95%). There was significantly higher stromal PgR expression in mammographically-dense breasts (p=0.026). Conclusions The proportion of stroma and fat underlies mammographic density in women at high risk of breast cancer. Increased expression of PgR in the stroma of mammographically dense breasts and frequent and unexpected presence of stromal ERα expression raises the possibility that hormone receptor expression in breast stroma may have a role in mediating the effects of exogenous hormonal therapy on mammographic density.

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.

The contribution of LARGE genomic rearrangements of BRCA1 and BRCA2 gene mutations in breast and ovarian cancer families in a clinical cohort

Background The use of multiplex ligation-dependent probe amplification (MLPA) to detect large scale rearrangements is now a standard component of BRCA1 and BRCA2 gene testing in the clinical setting. With the cost of full Sanger sequencing up to 4 times higher than the cost of MLPA, it is important not only to determine the prevalence of these mutations but to ascertain the probability that a family may harbour a large deletion or rearrangement in the BRCA1 and BRCA2 genes. Here we examine the incidence and clinical associations of genomic rearrangements in the BRCA1 and BRCA2 genes in a cohort of index cases from high risk breast and ovarian cancer families recruited from familial cancer centres (FCC).

Common genomic variants associated with breast cancer predict the risk of second primary breast cancer diagnosis

Background A diagnosis of a second primary breast cancer (‘bilateral breast cancer’) occurs in between 2-11% of women affected by breast cancer in the general population, but is increased in frequency in women with a family history of breast cancer. We investigated whether the common genomic variants described in breast cancer GWAS studies were determinants of the risk of bilateral breast cancer and compared the effect to that of family history.