Contralateral breast cancer after radiotherapy among BRCA1 and BRCA2 mutation carriers: A WECARE Study Report

BackgroundWomen with germline BRCA1 or BRCA2 (BRCA1/BRCA2) mutations are at very high risk of developing breast cancer, including asynchronous contralateral breast cancer (CBC). BRCA1/BRCA2 genes help maintain genome stability and assist in DNA repair. We examined whether the risk of CBC associated with radiation treatment was higher among women with germline BRCA1/BRCA2 mutations than among non-carriers.MethodsA population-based, nested case–control study was conducted within a cohort of 52,536 survivors of unilateral breast cancer (UBC). Cases were 603 women with CBC and controls were 1199 women with UBC individually matched on age at diagnosis, race, year of first diagnosis and cancer registry. All women were tested for BRCA1 and BRCA2 mutations. Radiation absorbed dose from the initial radiotherapy (RT) to the CBC location within the contralateral breast was reconstructed from measurements in a tissue-equivalent phantom and details available in the therapy records.FindingsAmong women treated with radiation, the mean radiation dose was 1.1 Gy (range = 0.02–6.2 Gy). Risk of developing CBC was elevated among women who carried a deleterious BRCA1/BRCA2 mutation (rate ratio, RR = 4.5, confidence interval, CI = 3.0–6.8), and also among those treated with RT (RR = 1.2, CI = 1.0–1.6). However, among mutation carriers, an incremental increase in risk associated with radiation dose was not statistically significant.InterpretationMultiplicative interaction of RT with mutation status would be reflected by a larger association of RT with CBC among carriers than among non-carriers, but this was not apparent. Accordingly, there was no clear indication that carriers of deleterious BRCA/BRCA2 mutations were more susceptible to the carcinogenic effects of radiation than non-carriers. These findings are reassuring and have important clinical implications for treatment decisions and the clinical management of patients harbouring deleterious BRCA1/BRCA2 mutations.FundingAll work associated with this study was supported by the U.S. National Cancer Institute [R01CA097397, U01CA083178].     

Numerous high-risk epithelial lesions in familial breast cancer

PurposeTo assess the occurrence of high-risk epithelial lesions in women of breast cancer families with and without a BRCA mutation.Patients and methodsProspective study of women at very high risk of breast cancer undergoing prophylactic mastectomy (68 BRCA1 mutation carriers, 14 BRCA2 mutation carriers and 24 non-BRCA mutation carriers).ResultsThe prevalence of high-risk lesions is equal in women with a BRCA1 or a BRCA2 mutation, but is higher in non-BRCA mutation carriers: all lesions 43% versus 71% (p = 0.02), atypical lobular hyperplasia 26% versus 67% (p = 0.001), atypical ductal hyperplasia 17% versus 42% (p = 0.01), lobular carcinoma-in situ 15% versus 29% (p = 0.10) and ductal carcinoma-in situ 9% versus 17% (p = 0.25). The presence of high-risk lesions is related to absence of a BRCA mutation and to age over 40 years.ConclusionWomen with an autosomal dominant family history for breast cancer, with and without a BRCA mutation are prone to develop high-risk epithelial lesions, especially over 40 years.     

Oral contraceptive use and breast or ovarian cancer risk in BRCA1/2 carriers: A meta-analysis

BackgroundWomen with BRCA1 or BRCA2 mutations are at increased risk of breast and ovarian cancer. Oral contraceptives (OC) use has been associated with a reduction in ovarian cancer risk and with a moderately increased breast cancer risk, which tends to level off in the few years after stopping. The association between oral contraceptive and BRCA1 or BRCA2 gene mutations carriers is unclear.MethodsWe performed a comprehensive literature search updated to March 2010 of studies on the associations between OC users and breast or ovarian cancer for ascertained BRCA1/2 carriers. We obtained summary risk estimated for ever OC users, for duration of use and time since stopping.ResultsA total of 2855 breast cancer cases and 1503 ovarian cancer cases, carrying an ascertained BRCA1/2 mutation, were included in our meta-analyses, based on overall 18 studies. Use of OC was associated with a significant reduced risk of ovarian cancer for BRCA1/2 carriers (summary relative risk (SRR) = 0.50; 95% confidence interval (CI), 0.33–0.75). We also observed a significant 36% risk reduction for each additional 10 years of OC use (SRR: 0.64; 95% CI, 0.53–0.78; P trend < 0.01). We found no evidence of a significant association between OC and breast cancer risk in carriers (SRR: 1.13; 95% CI, 0.88–1.45) and with duration of use. OC formulations used before 1975 were associated with a significant increased risk of breast cancer (SRR: 1.47; 95% 1.06, 2.04), but no evidence of a significant association was found with use of more recent formulations (SRR: 1.17; 95% 0.74, 1.86).ConclusionsOC users carrying an ascertained BRCA1/2 mutation have a reduced risk of ovarian cancer, proportional to the duration of use. There is no evidence that recent OC formulations increase breast cancer risk in carriers.     

Associations between RAD51D germline mutations and breast cancer risk and survival in BRCA1/2-negative breast cancers

BackgroundRAD51D is involved in DNA double-strand break repair by homologous recombination and plays an important role in the maintenance of genomic stability. The associations between RAD51D germline mutations and breast cancer risk and survival are not fully elucidated.Patients and methodsRAD51D germline mutations were determined using a multigene panel in 7657 unselected breast cancer patients who were negative for BRCA1/2 germline mutations. The RAD51D recurrent mutation p.K91fs was screened in 7947 healthy controls by Sanger sequencing.ResultsA total of 29 cases (0.38%) carried deleterious RAD51D germline mutations among this cohort of 7657 unselected breast cancer patients. The RAD51D recurrent mutation p.K91fs was identified in 18 cases (0.24%) of these 7657 patients. In contrast, the p.K91fs mutation was found in 8 of 7947 healthy controls with a frequency of 0.10%. The RAD51D p.K91fs mutation was significantly associated with increased breast cancer risk in unselected breast cancer [odds ratio = 2.34, 95% confidence interval (CI) 1.02–5.38; P = 0.040]. RAD51D mutation carriers were diagnosed at a younger age (P = 0.006) and were more likely to be triple-negative breast cancer (P = 0.003), estrogen receptor negative (P = 0.005) and high-grade cancers (P = 0.023) than noncarriers. Furthermore, RAD51D mutation carriers had a significantly worse recurrence-free survival [unadjusted hazard ratio (HR) = 3.00, 95% CI 1.56–5.80; P = 0.001] and distant recurrence-free survival (unadjusted HR = 2.54, 95% CI 1.14–5.67; P = 0.023) than noncarriers.ConclusionThe RAD51D recurrent mutation, p.K91fs, confers a moderately increased breast cancer risk, and RAD51D mutation carriers have an unfavorable survival compared with noncarriers.     

Clinical correlates of 'BRCAness' in triple-negative breast cancer of patients receiving adjuvant chemotherapy

BackgroundWe have previously reported an array comparative genomic hybridization profile that identifies triple-negative breast cancers (TNBC), with BRCA1 dysfunction and a high sensitivity to intensified dose bifunctional alkylating agents. To determine the effect of conventional-dose chemotherapy in patients with this so-called BRCA1-like profile, clinical characteristics and survival were studied in a large group of TNBC patients.Patients and methodsDNA was isolated and BRCA1-like status was assessed in 101 patients with early-stage TNBC receiving adjuvant cyclophosphamide-based chemotherapy. Clinical characteristics and survival were compared between BRCA1-like and non-BRCA1-like groups.ResultsSixty-six tumors (65%) had a BRCA1-like profile. Patients with BRCA1-like tumors tended to be younger and had more often node-negative disease (P = 0.06 and P = 0.03, respectively). Five-year recurrence-free survival was 80% for the BRCA1-like group and 75% for the non-BRCA1-like group (P = 0.35). T stage was the only variable significantly associated with survival.ConclusionsBRCA1-like tumors share clinical features, like young age at diagnosis and similar nodal status, with breast cancers in BRCA1 mutation carriers. Their prognosis is similar to that of non-BRCA1-like tumors when conventional-dose chemotherapy is administered. TNBCs that are classified as BRCA1-like may contain a defect in homologous recombination and could, in theory, benefit from the addition of poly ADP ribose polymerase inhibitors.     

The KL-VS sequence variant of Klotho and cancer risk in BRCA1 and BRCA2 mutation carriers

Klotho (KL) is a putative tumor suppressor gene in breast and pancreatic cancers located at chromosome 13q12. A functional sequence variant of Klotho (KL-VS) was previously reported to modify breast cancer risk in Jewish BRCA1 mutation carriers. The effect of this variant on breast and ovarian cancer risks in non-Jewish BRCA1/BRCA2 mutation carriers has not been reported. The KL-VS variant was genotyped in women of European ancestry carrying a BRCA mutation: 5,741 BRCA1 mutation carriers (2,997 with breast cancer, 705 with ovarian cancer, and 2,039 cancer free women) and 3,339 BRCA2 mutation carriers (1,846 with breast cancer, 207 with ovarian cancer, and 1,286 cancer free women) from 16 centers. Genotyping was accomplished using TaqMan^® allelic discrimination or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Data were analyzed within a retrospective cohort approach, stratified by country of origin and Ashkenazi Jewish origin. The per-allele hazard ratio (HR) for breast cancer was 1.02 (95% CI 0.93–1.12, P = 0.66) for BRCA1 mutation carriers and 0.92 (95% CI 0.82–1.04, P = 0.17) for BRCA2 mutation carriers. Results remained unaltered when analysis excluded prevalent breast cancer cases. Similarly, the per-allele HR for ovarian cancer was 1.01 (95% CI 0.84–1.20, P = 0.95) for BRCA1 mutation carriers and 0.9 (95% CI 0.66–1.22, P = 0.45) for BRCA2 mutation carriers. The risk did not change when carriers of the 6174delT mutation were excluded. There was a lack of association of the KL-VS Klotho variant with either breast or ovarian cancer risk in BRCA1 and BRCA2 mutation carriers.     

The impact of pregnancy on breast cancer survival in women who carry a BRCA1 or BRCA2 mutation

Physicians are often approached by young women with a BRCA mutation and a recent history of breast cancer who wish to have a baby. They wish to know if pregnancy impacts upon their future risks of cancer recurrence and survival. To date, there is little information on the survival experience of women who carry a mutation in one of the BRCA genes and who become pregnant. From an international multi-center cohort study of 12,084 women with a BRCA1 or BRCA2 mutation, we identified 128 case subjects who were diagnosed with breast cancer while pregnant or who became pregnant after a diagnosis of breast cancer. These women were age-matched to 269 mutation carriers with breast cancer who did not become pregnant (controls). Subjects were followed from the date of breast cancer diagnosis until the date of last follow-up or death from breast cancer. The Kaplan–Meier method was used to estimate 15-year survival rates. The hazard ratio for survival associated with pregnancy was calculated using a left-truncated Cox proportional hazard model, adjusting for other prognostic factors. Among women who were diagnosed with breast cancer when pregnant or who became pregnant thereafter, the 15-year survival rate was 91.5 %, compared to a survival of 88.6 % for women who did not become pregnant (adjusted hazard ratio = 0.76; 95 % CI 0.31–1.91; p = 0.56). Pregnancy concurrent with or after a diagnosis of breast cancer does not appear to adversely affect survival among BRCA1/2 mutation carriers.     

Risk-reducing salpingo-oophorectomy and breast cancer risk in BRCA1 or BRCA2 mutation carriers: A systematic review and meta-analysis

AimBRCA mutation carriers have a high lifetime risk of developing breast cancer (BC) and ovarian cancer (OC). Risk-reducing salpingo-oophorectomy (RRSO) has been shown to reduce OC risk. This meta-analysis was aim to analyze the effect of RRSO on the BC risk among BRCA1/2 mutation carriers.MethodsEmbase, PubMed, Web of Science, and Cochrane databases were searched for all studies investigating the effect of RRSO on BC risk. The pooled results were used to evaluate the association between RRSO and BC risk.ResultsThis meta-analysis included 13,965 BRCA1 and 7,057 BRCA2 mutation carriers from 14 observational studies. The pooled results showed that RRSO lowered BC risk among BRCA1 mutation carriers [hazard ratio (HR) = 0.63, 95% confidence interval (CI): 0.49–0.81, P < 0.01] and BRCA2 mutation carriers (HR = 0.51, 95% CI: 0.34–0.75, P < 0.01). RRSO reduced BC risk in younger women with BRCA1 mutation (HR = 0.48, 95% CI: 0.30–0.77, P < 0.01) and BRCA2 mutation (HR = 0.22, 95% CI: 0.08–0.65, P < 0.01). Analysis of the efficacy of RRSO at different time intervals after surgery showed a reduction of BC risk at <5 years after surgery in BRCA1 mutation carriers (HR = 0.60, 95% CI: 0.40–0.89, P = 0.01) and BRCA2 mutation carriers (HR = 0.42, 95% CI: 0.20–0.86, P = 0.02).ConclusionsRRSO is an effective way to reduce BC risk among women with BRCA1/2 mutation, especially in younger women. BRCA1/2 mutation carriers could benefit from RRSO in the immediate 5 years after surgery.     

Prevalence of BRCA1 mutations and responses to neoadjuvant chemotherapy among BRCA1 carriers and non-carriers with triple-negative breast cancer

Our study suggests that Chinese women with triple-negative breast cancer who are diagnosed at or before age of 50 are candidates forBRCA1 genetic testing regardless of family history. Furthermore,BRCA1-mutated triple-negative breast cancers are more likely to respond to neoadjuvant anthracycline-based regimens than non-BRCA1-mutated triple-negative breast cancers.BackgroundThe frequency ofBRCA1 germline mutations among Chinese women with triple-negative breast cancer is unclear, and the association betweenBRCA1 mutations and the response to neoadjuvant chemotherapy in women with triple-negative breast cancer has not been determined.Patients and methodsNine hundred and fifty-six triple-negative breast cancer patients were treated at our institute between 2003 and 2012; we tested theBRCA1/2 mutations for 956 patients and 953 patients in this cohort, respectively. Among the 956patients, 652 patients received neoadjuvant chemotherapy.ResultsIn this cohort, 7.1% (68/956) and 2.3% (22/953) of patients carried aBRCA1 orBRCA2 mutation, respectively. TheBRCA1/2 mutation rates were 10.5% and 3.0% among the patients who were diagnosed at or before the age of 50 in this cohort, respectively. The pCR (pathologic complete response) rate was 31.6% in the 652 patients who received neoadjuvant chemotherapy.BRCA1 carriers had a significantly higher pCR rate than non-carriers (BRCA1 carriers versus non-carriers, 53.8% versus 29.7%,P < 0.001). Among women treated with anthracycline with or without taxane regimens, the pCR rate was 57.1% forBRCA1 carriers, 29.0% for non-carriers (P < 0.001); among women treated with taxane regimens, the pCR rate was 40.0% forBRCA1 carriers, 32.9% for non-carriers (P = 0.73). At a median follow-up of 43 months, the recurrence-free survival was similar betweenBRCA1 carriers and non-carriers among the 947 patients of this study (adjusted hazard ratio = 0.92; 95% confidence interval: 0.45–1.90;P = 0.82).ConclusionsChinese women with triple-negative breast cancer who are diagnosed at or before age of 50 are candidates forBRCA1 genetic testing. Among triple-negative breast cancer patients,BRCA1 carriers are more likely to respond to neoadjuvant anthracycline-based regimens than are non-carriers.     

BRCA1 and BRCA2 families and the risk of skin cancer

BRCA1 and BRCA2 mutation carriers have elevated risks of breast and ovarian cancers. The risks for cancers at other sites remain unclear. Melanoma has been associated with BRCA2 mutations in some studies, however, few surveys have included non-melanoma skin cancer. We followed 2729 women with a BRCA1 or BRCA2 mutation for an average of 5.0 years. These women were asked to report new cases of cancer diagnosed in themselves or in their family. The risks of skin cancer were compared for probands with BRCA1 and BRCA2 mutations. Of 1779 women with a BRCA1 mutation, 29 developed skin cancer in the follow-up period (1.6%). Of the 950 women with a BRCA2 mutation, 28 developed skin cancer (3.0%) (OR = 1.83 for BRCA2 versus BRCA1; 95% CI 1.08–3.10; P = 0.02). The odds ratio for basal cell carcinoma was higher (OR = 3.8; 95% CI 1.5–9.4; P = 0.002). BRCA2 mutation carriers are at increased risk for skin cancer, compared with BRCA1 carriers, in particular for basal cell carcinoma.     

Risk of uterine cancer for BRCA1 and BRCA2 mutation carriers

BackgroundWhether BRCA1 and BRCA2 mutation carriers have a clinically relevant elevated risk of uterine cancer has implications for risk-reducing surgery.AimThis multicentre, prospective cohort study assessed uterine cancer risk for mutation carriers compared with the general population.MethodsEligible mutation carriers were enrolled in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab) cohort study, had a uterus present and no history of uterine cancer at cohort entry. Epidemiological, lifestyle and clinical data were collected at cohort entry and updated three-yearly. Cancer events were verified using pathology reports. Follow-up was censored at death or last contact. Relative risk of uterine cancer was estimated using the standardised incidence ratio (SIR), with the expected number of cases determined using population-based data for Australia.ResultsOf 1,111 mutation carriers in kConFab, 283 were excluded due to prior hysterectomy (N = 278), prior uterine cancer (N = 2) or being non-residents (N = 3). After a median follow-up of 9.0 years, five incident uterine cancers were reported in the 828 eligible women (419 had prior breast cancer and 160 had prior tamoxifen use), compared to 2.04 expected (SIR = 2.45; 95% confidence interval [CI]: 0.80–5.72; P = 0.11). In 438 BRCA1 mutation carriers and 390 BRCA2 mutation carriers, three and two incident cases of uterine cancer were reported, respectively, compared to 1.04 expected (SIR = 2.87; 95% CI: 0.59–8.43; P = 0.18) and 0.99 expected (SIR = 2.01; 95% CI: 0.24–7.30; P = 0.52), respectively. All cases were endometrioid subtype, International Federation of Gynaecology and Obstetrics stage I–II disease. No serous uterine cancers were reported.ConclusionsOur findings are consistent with those from most other reports and do not support routine risk-reducing hysterectomy for BRCA1 and BRCA2 mutation carriers.     

Mammographic changes resulting from benign breast surgery impair breast cancer detection at screening mammography

PurposeTo study possible explanations for lower screening performance after previous benign breast surgery.Patients and methodsWe included a consecutive series of 351,009 screening examinations in 85,274 women, obtained between January 1, 1997 and January 1, 2009. The examinations of women with screen detected cancers (SDC) or interval cancers (IC), diagnosed after previous benign breast surgery, were reviewed by two screening radiologists. They determined the presence and degree of post surgical changes, classified breast density and determined whether mammographic interpretation was hampered by tissue characteristics. They also assessed whether the cancer had already been visible at a previous screen.ResultsScreening sensitivity was lower in women with prior benign breast surgery than without (63.5% (115/181) versus 73.5% (1643/2236), p = 0.004). A total of 115 SDCs and 66 ICs were diagnosed in breasts after previous benign breast surgery. Post surgical mammographic alterations in the breast segment where cancer was diagnosed were more distinct in ICs than in SDCs (p = 0.001). Women with post surgical mammographic changes at the location of the breast cancer had an increased interval cancer risk (OR = 2.12, 95% confidence interval (CI) = 1.05–4.26). Limited mammographic interpretation due to tissue characteristics was mentioned, only in three SDCs and one IC. The proportions of SDCs and ICS that were already visible at a previous screen were comparable for women with and without prior surgery (SDC: 47.5% versus 43.8%, p = 0.3, IC: 50.0% versus 48.4%, p = 0.8).ConclusionPrevious benign breast surgery decreases screening sensitivity and this is likely due to postoperative mammographic changes.     

Predictors of contralateral breast cancer in BRCA1 and BRCA2 mutation carriers

Purpose:

The objective of this study was to estimate the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers; and measure the extent to which host, family history, and cancer treatment-related factors modify the risk.

Patients and methods:

Patients were 810 women, with stage I or II breast cancer, for whom a BRCA1 or BRCA2 mutation had been identified in the family. Patients were followed from the initial diagnosis of cancer until contralateral mastectomy, contralateral breast cancer, death, or last follow-up.

Results:

Overall, 149 subjects (18.4%) developed a contralateral breast cancer. The 15-year actuarial risk of contralateral breast cancer was 36.1% for women with a BRCA1 mutation and was 28.5% for women with a BRCA2 mutation. Women younger than 50 years of age at the time of breast cancer diagnosis were significantly more likely to develop a contralateral breast cancer at 15 years, compared with those older than 50 years (37.6 vs 16.8% P=0.003). Women aged <50 years with two or more first-degree relatives with early-onset breast cancer were at high risk of contralateral breast cancer, compared with women with fewer, or no first-degree relatives with breast cancer (50 vs 36% P=0.005). The risk of contralateral breast cancer was reduced with oophorectomy (RR 0.47; 95% CI 0.30–0.76; P=0.002).

Conclusion:

The risk of contralateral breast cancer risk in BRCA mutation carriers declines with the age of diagnosis and increases with the number of first-degree relatives affected with breast cancer. Oophorectomy reduces the risk of contralateral breast cancer in young women with a BRCA mutation.     

The androgen receptor CAG repeat polymorphism and modification of breast cancer risk in BRCA1 and BRCA2 mutation carriers

IntroductionThe androgen receptor (AR) gene exon 1 CAG repeat polymorphism encodes a string of 9–32 glutamines. Women with germline BRCA1 mutations who carry at least one AR allele with 28 or more repeats have been reported to have an earlier age at onset of breast cancer.MethodsA total of 604 living female Australian and British BRCA1 and/or BRCA2 mutation carriers from 376 families were genotyped for the AR CAG repeat polymorphism. The association between AR genotype and disease risk was assessed using Cox regression. AR genotype was analyzed as a dichotomous covariate using cut-points previously reported to be associated with increased risk among BRCA1 mutation carriers, and as a continuous variable considering smaller allele, larger allele and average allele size.ResultsThere was no evidence that the AR CAG repeat polymorphism modified disease risk in the 376 BRCA1 or 219 BRCA2 mutation carriers screened successfully. The rate ratio associated with possession of at least one allele with 28 or more CAG repeats was 0.74 (95% confidence interval 0.42–1.29; P = 0.3) for BRCA1 carriers, and 1.12 (95% confidence interval 0.55–2.25; P = 0.8) for BRCA2 carriers.ConclusionThe AR exon 1 CAG repeat polymorphism does not appear to have an effect on breast cancer risk in BRCA1 or BRCA2 mutation carriers.     

Do BRCA1 modifiers also affect the risk of breast cancer in non-carriers?

We studied whether or not single nucleotide polymorphisms (SNPs), which have been shown to modify the risk of breast cancer in women with a BRCA1 mutation, are associated with cancer risk in unselected (non-hereditary) breast cancer patients. We genotyped seven SNPs in six distinct genes (PHB, RAD51, ITGB3, TGFB1, VEGF, MTHFR) in 1100 unselected Polish breast cancer patients and 1100 controls. The frequencies of genotypes were similar in cases and controls. In a subgroup analysis, we found a positive association between the homozygous genotype PHB 1630C/T and medullary breast cancer (odds ratio (OR) = 4.0, 95% confidence interval (CI) 1.1–14.0). PHB 1630C/T was also associated with tumours negative for oestrogen receptor (OR = 2.2, 95% CI 1.13–4.4) or progesterone receptor (OR = 2.8, 95% CI 1.4–5.8). Our results show that, in general, the single nucleotide polymorphisms which modify the risk of hereditary breast cancer in Poland do not modify the risk of sporadic breast cancer. The PHB 1630 C/T single nucleotide polymorphism was associated with breast cancers with clinical features typical for BRCA1-positive tumours and is deserving of further study.     

The validation of a simulation model incorporating radiation risk for mammography breast cancer screening in women with a hereditary-increased breast cancer risk

IntroductionFor women with a BRCA1 or BRCA2 mutation or a strong family history of breast cancer, there is no clear estimation of the risk of tumour induction versus the beneficial effects of mammography screening available. This study aims to validate the Simulation Model on Radiation Risk and breast cancer Screening (SiMRiSc) model in these women, which can provide information on the benefits and risks of screening for breast cancer for various screening scenarios.MethodsThe simulation model for breast cancer screening was developed and the values for model parameters including cancer induction due to radiation were derived from the literature. The simulation model was validated by comparing the outcome data of the model with the data from three published screening studies of women with an increased hereditary breast cancer risk. A sensitivity analysis was used to estimate the error margins of the outcome data and to analyse the sensitivity of the simulation model to each parameter.ResultsThe model predicted 71 ± 4% of the reported tumours. When excluding the excess number of incident tumours detected in the first screening round, the model predicted 85 ± 6% of the tumours reported. The model was most sensitive to changes in the parameters related to lifetime breast cancer risk and sensitivity of mammography.ConclusionsWe conclude that the simulation model is suitable for the provision of accurate benefits’ and risks’ estimations necessary for the refinement of the screening guidelines for women at an increased risk of breast cancer.     

Proven non-carriers in BRCA families have an earlier age of onset of breast cancer

BackgroundRisk estimates for proven non-carriers in BRCA mutation families are inconsistent for breast cancer and lacking for ovarian cancer. We aimed to assess the age-related risks for breast and ovarian cancer for proven non-carriers in these families.MethodsA consecutive cohort study ascertained 464 proven non-carriers who had a first-degree relative with a pathogenic BRCA mutation. Kaplan–Meier analyses were used to estimate the age-related cancer risks, and we calculated standardised incidence ratios.ResultsIn the 464 non-carriers, 17 breast cancers and two ovarian cancers were detected at a mean age of 47 years (95% confidence interval (CI) 32–61) and 49 years (95% CI 32–67), respectively. Overall, by the age of 50, the breast and ovarian cancer risks among non-carriers were 6.4% (95% CI 2.9–9.8%) and 0.4% (95% CI 0–1.3%), of which the breast cancer risk was statistically significantly higher than the risk in the general population. In particular, the number of breast cancers among non-carriers in BRCA1 families was higher than expected for the general population (standardised incidence ratio (SIR) 2.0, 95% CI 1.1–3.3). In the BRCA1 cohort, the mean number of breast cancer cases was higher in families in which non-carriers were diagnosed before the age of 50 (p = 0.04).ConclusionThe age at diagnosis of breast cancer in non-carriers in BRCA mutation families is younger than expected, yielding an increased risk in the fifth decade. This effect is most evident in BRCA1 families. If our results are confirmed by others, this could affect the advice given on breast cancer screening to proven non-carriers between the age of 40 and 50 in such families.     

Breast cancer risk after age 60 among BRCA1 and BRCA2 mutation carriers

Purpose

It is not known whether the risk of breast cancer among BRCA1 and BRCA2 mutation carriers after age 60 is high enough to justify intensive screening or prophylactic surgery. Thus, we conducted a prospective analysis of breast cancer risk in BRCA1 and BRCA2 mutation carriers from age 60 until age 80.

Methods

Subjects had no history of cancer and both breasts intact at age 60 (n?=?699). Women were followed until a breast cancer diagnosis, prophylactic bilateral mastectomy or death. We calculated the annual cancer rate and cumulative incidence of breast cancer (invasive and in situ) from age 60 to age 80. We assessed the associations between hormone replacement therapy, family history of breast cancer and bilateral oophorectomy and breast cancer risk.

Results

Over a mean follow-up of 7.9 years, 61 invasive and 20 in situ breast cancers were diagnosed in the cohort. The mean annual rate of invasive breast cancer was 1.8% for BRCA1 mutation carriers and 1.7% for BRCA2 mutation carriers. The cumulative risk of invasive breast cancer from age 60 to 80 was 20.1% for women with a BRCA1 mutation and was 17.3% for women with a BRCA2 mutation. Hormone replacement therapy, family history and oophorectomy were not associated with breast cancer risk.

Conclusions

Findings from this large prospective study indicate that the risk of developing breast cancer remains high after age 60 in both BRCA1 and BRCA2 mutation carriers. These findings warrant further evaluation of the role of breast cancer screening in older mutation carriers.

     

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

BackgroundFew data exist regarding the use of complementary and alternative medicine (CAM) by unaffected women at high risk of breast cancer.MethodsSelf-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.ResultsOf 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).ConclusionsThe 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.     

Excess breast cancer risk in first degree relatives of CHEK211100delC positive familial breast cancer cases

AimThe CHEK211100delC mutation confers a relative risk of two for breast cancer (BC) in the general population. This study aims to explore the excess cancer risk due to the CHEK211100delC mutation within a familial non-BRCA1/2 breast cancer setting.Patients and MethodsCancer incidences were compared between first degree relatives of 107 familial breast cancer patients positive for the CHEK211100delC mutation (CHEK2 positive families) and first degree relatives of 314 familial breast cancer patients without the CHEK211100delC mutation (CHEK2 negative families). All families were derived from the same pool of familial non-BRCA1/2 breast cancer families (n = 2554). Medical information of 2188 first degree relatives of these families was analysed for cancer risk. CHEK211100delC status of relatives was unknown.ResultsIncreased breast cancer risk (hazard ratio (HR) 2.0 (95% confidence interval (CI): 1.4–2.7), p < 0.001) was observed in sisters of CHEK211100delC positive index cases compared to sisters of CHEK211100delC negative index cases. HR was 1.6 (95% CI: 1.0–2.4) for mothers of CHEK2 positive versus negative index cases (p = 0.041). For second primary breast cancers HR was increased in CHEK211100delC positive index cases (HR 2.1, 95% CI: 1.3–3.3, p = 0.003) and their sisters (HR 2.6, 95% CI: 1.1–6.1, p = 0.025).ConclusionThere is an excess breast cancer risk in first degree relatives of CHEK211100delC positive non-BRCA1/2 familial breast cancer patients compared to non-CHEK211100delC familial breast cancer relatives.Genotyping for the CHEK211100delC mutation in a familial breast cancer setting contributes to optimal clinical surveillance in countries in which this mutation is prevalent. Carriers and female relatives are eligible for stringent breast surveillance programs.