The influence of familial and hereditary factors on the prognosis of breast cancer

Background: Family history is a well recognized risk factor for breast cancer, but its impact in terms of breast cancer survival is uncertain. The recent identification of breast cancer predisposing genes has provided new clinical insights in this field.Design: English literature identified through Medline between 1976 and February 1999 was reviewed including search terms: breast cancer, survival, prognosis, family history, genetics, BRCA1, BRCA2, and related articles.Results: Publications were divided into three categories.Family history-based studies: eighteen articles were reviewed. Four studies showed a statistically significant better survival in patients with a family history of breast cancer, and two studies demonstrated a significantly worse prognosis in this context. The remaining articles showed no significant difference. Linkage studies: Two studies based on linkage to BRCA1 found that overall survival was better in linked families. A third one concluded to a worse outcome in BRCA2-linked tumors. Mutation-based studies: 10 studies looking at the association between germ-line mutations in BRCA1/BRCA2 and clinical outcomes were reviewed. Eight articles reported no significant difference in outcome, whereas two studies showed a worse outcome in patients with mutations.Conclusions: Conflicting data exist as to whether the prognosis of familial or hereditary breast cancer differs from that of sporadic cases. Some of the discrepancies may be explained by methodological differences or biases. However, no studies showed a survival advantage for BRCA1mutation carriers. This seems to indicate that BRCA1-related breast cancer is not associated with a survival advantage, and that in fact, certain BRCA1 germline mutations confer a worse prognosis. However, to adequately answer this question, more efficient molecular tools to identify all the genetic changes responsible for breast cancer predisposition, and large cohort studies to evaluate their clinical consequences, are needed.     

miRNA expression patterns in normal breast tissue and invasive breast cancers of BRCA1 and BRCA2 germ-line mutation carriers

miRNA deregulation has been found to promote carcinogenesis. Little is known about miRNA deregulation in hereditary breast tumors as no miRNA expression profiling studies have been performed in normal breast tissue of BRCA1 and BRCA2 mutation carriers. miRNA profiles of 17 BRCA1- and 9 BRCA2-associated breast carcinomas were analyzed using microarrays. Normal breast tissues from BRCA1 and BRCA2 mutation carriers (both n = 5) and non-mutation carriers (n = 10) were also included. Candidate miRNAs were validated by qRT-PCR. Breast carcinomas showed extensive miRNA alteration compared to normal breast tissues in BRCA1 and BRCA2 mutation carriers. Moreover, normal breast tissue from BRCA1 mutation carriers already showed miRNA alterations compared to non-mutation carriers. Chromosomal distribution analysis showed several hotspots containing down- or up-regulated miRNAs. Pathway analysis yielded many similarities between the BRCA1 and BRCA2 axes with miRNAs involved in cell cycle regulation, proliferation and apoptosis. Lesser known pathways were also affected, including cellular movement and protein trafficking. This study provides a comprehensive insight into the potential role of miRNA deregulation in BRCA1/2-associated breast carcinogenesis. The observed extensive miRNA deregulation is likely the result of genome-wide effects of chromosomal instability caused by impaired BRCA1 or BRCA2 function. This study''s results also suggest the existence of common pathways driving breast carcinogenesis in both BRCA1 and BRCA2 germ-line mutation carriers.     

Reproductive factors in hereditary breast cancer

Background: An early age at menarche, a short menstrual cycle length, and a high age at first full term pregnancy or nulliparity are known risk factors for breast cancer. These risk factors have previously been reported to differ between breast cancer patients with and without a family history of breast cancer and also between breast cancer patients and controls. Methods: Self-administered questionnaires were filled out by 95 women belonging to 24 families with known BRCA1 mutations, 16 women belonging to nine families with known BRCA2 mutations, and 95 women belonging to 65 families with hereditary breast cancer where no BRCA1 or BRCA2 mutations could be detected. Thirty-nine women were BRCA1 mutation carriers and 56 women were BRCA1 negative, 11 women were BRCA2 carriers and five BRCA2 negative. All women were born between 1905 and 1979. Results: Age at menarche, physiological menstrual cycle length at age 30 or at current age in younger women (when not using oral contraceptives), age at first full term pregnancy, and nulliparity did not significantly differ between BRCA1 mutation carriers and BRCA1 negative women. Too few women were BRCA2 negative to serve as a control group. BRCA2 mutation carriers were therefore compared with BRCA1 negative and BRCA2 negative women. None of the above reproductive factors did significantly differ between BRCA2 mutation carriers and from BRCA1 and BRCA2 families. Women from non-BRCA1/BRCA2 hereditary breast cancer families had a higher age at menarche, but this was no longer significant after adjustment for other factors in a multivariate model. Conclusion: Our results suggest that reproductive risk factors of breast cancer are not related to BRCA1 or BRCA2 carrier status. There was also no indication that these factors differ in carriers of unknown susceptibility genes compared with non-carriers from BRCA1 and BRCA2 families.     

Earlier age of onset of BRCA mutation-related cancers in subsequent generations

BACKGROUND:

Women who are diagnosed with a deleterious mutation in either breast cancer (BRCA) gene have a high risk of developing breast and ovarian cancers at young ages. In this study, the authors assessed age at diagnosis in 2 generations of families with known mutations to investigate for earlier onset in subsequent generations.

METHODS:

Of the 132 BRCA‐positive women with breast cancer who participated in a high‐risk protocol at The University of Texas MD Anderson Cancer Center (Gen 2), 106 women could be paired with a family member in the previous generation (Gen 1) who was diagnosed with a BRCA‐related cancer (either breast cancer or ovarian cancer). Age at diagnosis, location of the mutation, and year of birth were recorded. A previously published parametric anticipation model was applied in these genetically predisposed families.

RESULTS:

The median age of cancer diagnosis was 42 years (range, 28‐55 years) in Gen 2 and 48 years (range, 30‐72 years) in Gen 1 (P < .001). In the parametric model, the estimated change in the expected age at onset for the entire cohort was 7.9 years (P < .0001). Statistically significant earlier ages at diagnosis also were observed within subgroups of BRCA1 and BRCA2 mutations, maternal inheritance, paternal inheritance, breast cancer only, and breast cancer‐identified and ovarian cancer‐identified families.

CONCLUSIONS:

Breast and ovarian cancers in BRCA mutation carriers appeared to be diagnosed at an earlier age in later generations. The authors concluded that patients who are younger at the onset of BRCA‐related cancers should continue to be tracked to offer appropriate screening modalities at appropriate ages. Cancer 2011. © 2011 American Cancer Society.     

BRCA2 germ-line mutations in Spanish male breast cancer patients

Background:Mutations in the BRCA2 gene account for the majorityof the families with male and female breast cancer cases, and a number ofBRCA2 mutations have been reported in males with breast cancer. The aim ofthis study was to characterise BRCA2 germ-line mutations in Spanish malebreast cancer patients.Patients and methods:We screened DNA from 11 affected men and 6women with breast cancer (BC) who had an affected male relative (father orbrother). Exons 2–9 and 12–27 were screened by SSCP, and exons 10and 11 were screened by PTT. PCR products with a variant band were sequenced.Results:Three BRCA2 frameshift mutations were identified(17.6%): the 3374delA in codon 1049 (exon 11), 6857delAA in codon 2010(exon 11), and 9254delATCAT in codon 3009 (exon 23). These mutations werepresent in patients with affected first-degree relatives (3 of 9, 33%).The proportion of male patients with a family history of BC in at least onefirst-degree relative was 53%.Conclusions:There is an association between BRCA2 mutations andmale breast cancer, especially in those with a family history of BC. The highprevalence of BRCA2 mutations among males should be considered when estimatingrisk for female relatives. All new male cases of BC should be regarded asbeing possibly inherited and should be fully investigated.     

MicroRNA expression signatures for the prediction of BRCA1/2 mutation‐associated hereditary breast cancer in paraffin‐embedded formalin‐fixed breast tumors

Screening for germline mutations in breast cancer‐associated genes BRCA1 and BRCA2 is indicated for patients with breast cancer from high‐risk breast cancer families and influences both treatment options and clinical management. However, only 25% of selected patients test positive for BRCA1/2 mutation, indicating that additional diagnostic biomarkers are necessary. We analyzed 124 formalin‐fixed paraffin‐embedded (FFPE) tumor samples from patients with hereditary (104) and sporadic (20) invasive breast cancer, divided into two series (A and B). Microarray expression profiling of 829 human miRNAs was performed on 76 samples (Series A), and bioinformatics tool Prophet was used to develop and test a microarray classifier. Samples were stratified into a training set (n = 38) for microarray classifier generation and a test set (n = 38) for signature validation. A 35‐miRNA microarray classifier was generated for the prediction of BRCA1/2 mutation status with a reported 95% (95% CI = 0.88–1.0) and 92% (95% CI: 0.84–1.0) accuracy in the training and the test set, respectively. Differential expression of 12 miRNAs between BRCA1/2 mutation carriers versus noncarriers was validated by qPCR in an independent tumor series B (n = 48). Logistic regression model based on the expression of six miRNAs (miR‐142‐3p, miR‐505*, miR‐1248, miR‐181a‐2*, miR‐25* and miR‐340*) discriminated between tumors from BRCA1/2 mutation carriers and noncarriers with 92% (95% CI: 0.84–0.99) accuracy. In conclusion, we identified miRNA expression signatures predictive of BRCA1/2 mutation status in routinely available FFPE breast tumor samples, which may be useful to complement current patient selection criteria for gene testing by identifying individuals with high likelihood of being BRCA1/2 mutation carriers.     

Survival of breast cancer patients in BRCA1, BRCA2, and non-BRCA1/2 breast cancer families: a relative survival analysis from Finland.

Reports on the prognosis of familial breast cancer patients have been contradictory. True differences in survival, if they exist, would have important implications for genetic counselling and in treatment of hereditary breast cancer. We assessed the survival rates of 359 familial breast cancer patients (32 patients from BRCA1-positive families, 43 patients from BRCA2-positive families and 284 patients from BRCA1/2-negative breast cancer families) and compared them with those of all other breast cancer patients diagnosed in Finland from 1953 to 1995 (n = 59,517). Cumulative relative survival rates (RSR) were calculated by dividing the observed survival rates by the expected ones. The expected survival rates were derived from the sex, age and calendar year specific life-tables of the general population in Finland. Regression model was used to calculate relative excess risk of death (RR) and to adjust for confounding factors. The overall 5-year RSR of the patients in the BRCA1 families, BRCA2 families, non-BRCA1/2 families and among sporadic cases was 67%, 77%, 86% and 78%, respectively. However, we found no significant differences in the RR adjusted for age, stage and year of diagnosis between the different familial patient groups or the general breast cancer population. In the BRCA1 families the RR tended to be higher [RR 1.30, 95% confidence interval (CI) 0.63--2.70] and in the BRCA2 families lower (RR 0.78, 95% CI 0.39--1.57) than among the general breast cancer patient population. The RR among patients in the non-BRCA1/2 families did not differ from that of the general patient population.     

MicroRNA-based molecular classification of non-BRCA1/2 hereditary breast tumours

Background:

Hereditary breast cancer comprises 5–10% of all breast cancers. Mutations in two high-risk susceptibility genes, BRCA1 and BRCA2, along with rare intermediate-risk genes and common low-penetrance alleles identified, altogether explain no more than 45% of the high-risk breast cancer families, although the majority of cases are unaccounted for and are designated as BRCAX tumours. Micro RNAs have called great attention for classification of different cancer types and have been implicated in a range of important biological processes and are deregulated in cancer pathogenesis.

Methods:

Here we have performed an exploratory hypothesis-generating study of miRNA expression profiles in a large series of 66 primary hereditary breast tumours by microarray analysis.

Results:

Unsupervised clustering analysis of miRNA molecular profiles revealed distinct subgroups of BRCAX tumours, ‘normal-like'' BRCAX-A, ‘proliferative'' BRCAX-B, ‘BRCA1/2-like'' BRCAX-C and ‘undefined'' BRCAX-D subgroup. These findings introduce a new insight in the biology of hereditary breast cancer, defining specific BRCAX subgroups, which could help in the search for novel susceptibility pathways in hereditary breast cancer.

Conclusion:

Our data demonstrate that BRCAX hereditary breast tumours can be sub-classified into four previously unknown homogenous groups characterised by specific miRNA expression signatures and histopathological features.     

Development of a knowledge scale about breast cancer and heredity (BCHK)

An 11item questionnaire, the Breast Cancer and Heredity Knowledge Scale (BCHK), was developed to test general knowledge about breast cancer and hereditary breast cancer (HBC) among women at low to moderate risk of HBC. The BCHK measures knowledge about breast cancer incidence and prognosis, risk factors, screening, disease presentation and treatment, and HBC. Scale items were generated from focus group interviews, previously published breast cancer knowledge scales, and consulation with a multidisciplinary research team, including health professionals and women with breast cancer or a family history of breast cancer. A 27item draft scale was tested on 36 breast clinic patients and 17 women from the general public. Results were used to develop the final 11item scale. Development of the scale and its potential uses are discussed.     

353例遗传性高危乳腺癌患者BRCA1、BRCA2、PALB2基因胚系突变的分布情况研究

[目的]通过对女性乳腺癌患者进行胚系基因检测,评估BRCA1、BRCA2、PALB2基因胚系致病/可能致病性突变在高危乳腺癌患者中的分布情况。[方法]收集2016年12月1日至2022年4月30日中山大学附属第一医院收治的女性乳腺癌患者,对已进行胚系多基因检测的353例具有遗传性高危因素的女性乳腺癌患者,对她们的检测结果进行分析,评估BRCA1、BRCA2和PALB2基因胚系致病/可能致病性突变患者的病理和临床特征等情况。[结果] 353例患者中,胚系BRCA1、BRCA2和PALB2致病/可能致病突变者共59例,突变率为16.71%,年轻患者较其他年龄患者的BRCA1突变率更高（P=0.039）,相比其他分子分型,三阴性乳腺癌患者的BRCA1突变（P<0.001）和3个基因的总突变率（P=0.007）都明显更高。和没有肿瘤家族史的患者相比,有肿瘤家族史的患者并没有体现出明显的高突变率。具有2个或2个以上危险因素的患者的基因突变率要明显高于只有1个高危因素的患者（P=0.048）。[结论] PALB2基因胚系致病/可能致病突变在高危乳腺癌患者中的发生比例较高,其重要性并不亚于BR...     

The impact of having relatives affected with breast cancer on psychological distress in women at increased risk for hereditary breast cancer

Purpose.Being at hereditary risk of breast cancer (BC) may lead to elevated levels of distress because of the impact of the BC-process in relatives.Objective.Determine the association between psychological distress and BC in relatives. We studied: kind of kinship with the affected relative(s), degree of involvement with the relatives BC, time elapsed since the BC diagnosis of the relative, and loss of a relative as a consequence of BC.Methods.The study cohort consisted of women at increased risk of developing BC, adhering to regular surveillance and participating in the Dutch MRISC-study. Two months prior to the surveillance appointment, demographics, general and BC specific distress and experience with BC in the family were assessed.Results.347 out of 351 participants (mean age 40 1/2) had at least one relative affected with BC. The following variables were significantly, positively related to BC specific distress: having at least one affected sister (n=105; p < 0.04); close involvement in a sisters BC process (n=94; p < 0.03); and a recent (less than three years ago) BC diagnosis in a sister (n=30; p < 0.03). General distress did not show any significant associations with the experience of BC in the family.Conclusion. These findings show the impact of a BC diagnosis in a sister, particularly a recent diagnosis, on psychological distress. Women who have experienced BC in their sister may be in need of additional counselling or of more attention during the surveillance process.     

An audit of screening for familial breast cancer before 50 years in the South Thames Region – have we got it right?

We have carried out an audit of breast screening by mammography under 50 years of age in a cohort of 192 women attending family cancer clinics run by the South Thames genetic services. Of these women, six came from families in which a BRCA mutation had been identified, 61 had > 50%, 35 a 20–50% and 90 had < 20% chance of carrying a high risk mutation. In the 192 women in the screened cohort, 9 breast cancers were diagnosed (4.7%), all in high-risk women. Three were diagnosed at the prevalence screen. Three were detected mammographically at subsequent screening rounds; three were detected by breast self-examination (BSE) between screening episodes. One interval cancer was visible on mammogram at presentation but not at screening five months previously. A second cancer was also visible on mammogram at presentation but the normal screening mammogram had been 17 months earlier, outside the recommended interval. The remaining interval cancer was not visible on the mammogram. A total of 363 two-view screening mammograms were performed in the 280 person-years of follow-up; 109 additional investigations were generated: 23 recall mammograms, 18 symptomatic mammograms, 45 ultrasounds, 12 aspiration cytologies and 11 biopsies. Cytology diagnosed malignancy in 1 of 12 cases; breast biopsy in 9 of 11 cases. Twenty-three additional women had ultrasound screening only. This audit suggests that screening below the age 50 years may be unnecessary in families with a low chance of having a BRCA1 or -2 mutation, but it is important to screen high-risk women at least annually and possibly under 35 years. This revised version was published online in July 2006 with corrections to the Cover Date.     

Role of micronucleus test in predicting breast cancer susceptibility: a systematic review and meta-analysis

Background:

The cytokinesis-block micronucleus test (MNT), as a marker of chromosomal mutagen sensitivity, was applied in a number of studies enrolling breast cancer (BC) patients and subjects with known or putative genetic predisposition to BC. The large majority of them involve the evaluation of induced micronuclei (MN) frequency in peripheral lymphocytes, after the in vitro challenge with ionising radiations.

Methods:

The aim of the present systematic review and meta-analysis is to investigate the role of MN assay in the identification of individuals at increased risk of BC and its potential use as prescreening test in women with a family history (FH) of BC.

Results:

Twelve studies were included in the meta-analysis, covering a time interval 1998–2007, and including 752 cases and 593 controls. Among the cases, 629 are cancer patients and 123 are cancer-free subjects, including 32 first-degree relatives of the susceptible subjects and 91 BRCA1/2 mutation carriers. Our meta-analysis reveals a significant increase of baseline MN frequency related to cancer status, but the association with FH of BC and specifically with BRCA mutations is not clear. A larger difference in MN frequency between cases and controls was observed after in vitro challenge, but response to radiation exposure doesn''t appear to better discriminate cancer-susceptible subjects.

Conclusion:

Our study suggests the presence of some bias affecting many of these studies, reinforcing the suggestion that a more rigorous study design is needed in this area.     

Evidence-based management options for women at increased breast/ovarian cancer risk.

Recent developments in our ability to predict breast cancer risk necessitates primary care physicians learn to evaluate breast cancer risk and its importance in shaping decisions concerning surveillance and risk reduction measures. This article reviews the current opinion on risk assessment and management of women with an increased risk of breast/ovarian cancer. Management options are given for women at slightly, moderately and highly elevated breast cancer risk, as well as for BRCA1/2 carriers, based on currently available evidence.     

Lack of Germ-line Mutations at the Specific BRCA1-IRIS Coding Sequence in 114 Spanish High-risk Breast/ovarian Families

A new BRCA1 locus product called BRCA1-IRIS has been identified recently. High-risk breast/ovarian families have not been screened for germ-line mutations at the specific BRCA1-IRIS coding sequence, as it was considered merely as part of BRCA1 intron 11. Here we report the first comprehensive screening of germ-line mutations in a cohort of 116 index cases from high-risk breast/ovarian families in which no germ-line mutation was identified in BRCA1 or BRCA2. We did not find germ-line mutations at the specific BRCA1-IRIS coding sequence in any sample. The only heterozygous patter identified by DGGE was caused by a C to A substitution in the non-coding 3′ sequence, 123 bases downstream of the BRCA1-IRIS stop codon (IVS11+268C/A). The data indicates that it is probably a neutral change not associated with cancer risk. Our analysis suggests that the role of germ-line mutations at the specific BRCA1-IRIS sequence in breast cancer susceptibility, if any, is marginal and do not explain a significant fraction of high-risk breast/ovarian families, at least in the population analyzed.     

Prevalence of BRCA1 and BRCA2 mutations in Pakistani breast and ovarian cancer patients

Among Asian countries, Pakistan has the highest rates of breast and ovarian cancer. To assess the contribution of the BRCA1 and BRCA2 germ line mutations to these high rates, we conducted the first study of 176 Pakistani breast and ovarian cancer patients, selected on family history and on age of diagnosis. Comprehensive BRCA mutation screening was performed using a range of techniques, including denaturing high-pressure liquid chromatography, single strand conformational polymorphism analysis and protein truncation test, followed by DNA sequencing. Thirty deleterious germ-line mutations were identified in the 176 families (17.0%), including 23 in BRCA1 and 7 in BRCA2. Four mutations, 185delAG, 185insA, S1503X and R1835X, were recurrent; these accounted for 52% of all identified BRCA1 mutations. Haplotype analyses suggested founder effects for 3 of these. The prevalence of BRCA1 or BRCA2 mutations was 42.8% for families with multiple cases of breast cancer, and was 50.0% for the breast/ovarian cancer families. The prevalence of mutations was 11.9% for single cases of early-onset breast cancer (< or =30 years) and was 9.0% for single cases of early-onset ovarian cancer (< or =45 years). Our findings show that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer and early-onset breast and ovarian cancer cases in Pakistan.