Collaboration of breast cancer clinic and genetic counseling division for BRCA1 and BRCA2 mutation family in Japan

BACKGROUND: BRCA1 and BRCA2 mutations cause high breast cancer incidence rates as high as 80% Although prophylactic therapy is still controversial, several prophylactic therapies have been proposed and tried for BRCA1 and BRCA2 mutation carriers. Prophylactic surgery, chemo-prevention and precise screening have been proposed as prophylactic therapy. All BRCA1 and BRCA2 mutation carriers need knowledge about their disease and the countermeasures that are used to protect against onset of disease. Counseling plays an important role in this regard for people with genetic diseases. Therefore, collaboration between breast cancer clinics and genetic counseling services is the most important issue in clinical practice. Our group consists of three national universities and a general hospital. In this article we describe our trial to construct a clinical system against hereditary breast cancer as an interim report for the Japanese Ministry of Health, Labour and Welfare. PATIENTS AND METHODS: Twenty familial breast cancer patients were registered in this study. The whole sequence of BRCA1 and BRCA2 were analyzed. If pathological mutations were detected, their first degree families were introduced to the counseling division at each institute when candidates visited counseling divisions. RESULTS AND DISCUSSION: Four cases of a deleterious mutation in BRCA1 or BRCA2 were detected among 20 cases. Their first degree relatives are now under consideration for visiting counseling divisions. The clinical system described in this study should play a role to protect BRCA1 or BRCA2 mutation carriers in Japan.     

Prevalence of BRCA1 and BRCA2 genomic rearrangements in a cohort of consecutive Italian breast and/or ovarian cancer families

Germline point mutations in BRCA1 and BRCA2 genes account for about 30% of the inherited breast and ovarian cancers. Germline genomic rearrangements have been found in both BRCA1 and BRCA2 genes, but the extent to which these alterations might contribute to increasing the actual mutation detection rate is still debated. Here we screened a cohort of 112 consecutive Italian families at moderate-to-high risk for breast and/or ovarian cancer for BRCA1 and BRCA2 point mutations and genomic rearrangements. Of the 83 point mutation negative probands, two (2.4%) showed BRCA1 rearrangements, accounting for 10.5% of the BRCA1 mutations. BRCA1 del18–19 has been previously described in another Italian family, while the molecular characterization of the BRCA1 del23–24 is given here for the first time. Conversely, we failed to identify any BRCA2 rearrangements even in the hereditary breast cancer families, where we detected an higher prevalence of BRCA2 compared to BRCA1 point mutations. Our results support the idea that search for BRCA1 rearrangements should be included in the genetic screening of even moderate risk breast/ovarian cancer families. In contrast, they suggest BRCA2 rearrangements might be very rare out of the high risk families including a male breast cancer.     

Clinicopathological features of hereditary breast cancer

The possible role of germline mutations ofBRCA1 andBRCA2 as causative agents of familial breast cancer was assessed. Their possible involvement in the carcinogenesis of hereditary breast cancer was investigated using 63 clinically suspect families. Twenty-one lineages (33.3%) had mutations in one of the twoBRCA genes. This relatively low incidence suggested that germline mutations in unknown genes are involved in the carcinogenesis of hereditary breast cancer in the Japanese population. However, the clinicopathological features characteristic of hereditary breast cancer, such as early disease onset, a high incidence of bilateral breast cancer, and a high incidence of multiple primary carcinomas in other organs were confirmed in the present study.     

No association of TGFB1 L10P genotypes and breast cancer risk in BRCA1 and BRCA2 mutation carriers: a multi-center cohort study

Background The transforming growth factor β-1 gene (TGFB1) is a plausible candidate for breast cancer susceptibility. The L10P variant of TGFB1 is associated with higher circulating levels and secretion of TGF-β, and recent large-scale studies suggest strongly that this variant is associated with breast cancer risk in the general population. Methods To evaluate whether TGFB1 L10P also modifies the risk of breast cancer in BRCA1 or BRCA2 mutation carriers, we undertook a multi-center study of 3,442 BRCA1 and 2,095 BRCA2 mutation carriers. Results We found no evidence of association between TGFB1 L10P and breast cancer risk in either BRCA1 or BRCA2 mutation carriers. The per-allele HR for the L10P variant was 1.01 (95%CI: 0.92–1.11) in BRCA1 carriers and 0.92 (95%CI: 0.81–1.04) in BRCA2 mutation carriers. Conclusions These results do not support the hypothesis that TGFB1 L10P genotypes modify the risk of breast cancer in BRCA1 or BRCA2 mutation carriers.     

BRCA1 andBRCA2 germline mutations in Japanese with hereditary breast cancer families

We examined germline mutations inBRCA1 andBRCA2 in 23 Japanese breast cancer families, using PCR-SSCP analysis. The same nonsense mutation (exon 5, Leu63ter) ofBRCA1 was detected in two different families. Three different mutations resulting in a truncatedBRCA2 protein (exon 9, 20, 24) were detected in three different families, including one male case of breast cancer. One base substitution mutation inBRCA2, A10462G, was detected in the other two families. Although the mean age of onset for breast cancer in families with theBRCA1- mutation was 50 years, the age of onset in families with theBRCA2-mutation was from 28 to 43 years. Among the 23 families examined, two families had members with ovarian cancers, three had members with prostate cancers, and one had a pancreatic cancer. However, none of these families was positive for theBRCA1 orBRCA2 mutation. Histopathologically, we observed a prevalence of histological grade 3 inBRCA2-associated familial breast cancers, because of nuclear atypia, structural atypia and mitotic activity. It is suggested thatBRCA2 may play a more important role thanBRCA1 in Japanese familial breast cancers, and these mutations are related to the aggressive nature and highly proliferative activity of the tumors.     

A prior diagnosis of breast cancer is a risk factor for breast cancer in BRCA1 and BRCA2 carriers

Background

The risk of breast cancer in carriers of BRCA1 and BRCA2 mutations is influenced by factors other than the genetic mutation itself. Modifying factors include a woman’s reproductive history and family history of cancer. Risk factors are more likely to be present in women with breast cancer than in women without breast cancer, and therefore the risk of cancer in the two breasts should not be independent. It is not clear to what extent modifying factors influence the risk of a first primary or a contralateral breast cancer in BRCA carriers.

Methods

We conducted a matched case–control study of breast cancer among 3920 BRCA1 or BRCA2 mutation carriers. We asked whether a past history of breast cancer in the contralateral breast was a risk factor for breast cancer.

Results

After adjustment for age, country of residence, and cancer treatment, a previous cancer of the right breast was found to be a significant risk factor for cancer of the left breast among BRCA1 or BRCA2 carriers (relative risk: 2.1; 95% confidence interval: 1.4 to 3.0; p < 0.0001).

Conclusions

In a woman with a BRCA1 or BRCA2 mutation who is diagnosed with breast cancer, the risk of cancer in the contralateral breast depends on the first diagnosis. That observation supports the hypothesis that there are important genetic or non-genetic modifiers of cancer risk in BRCA carriers. Discovering risk modifiers might lead to greater personalization of risk assessment and management recommendations for BRCA-positive patients.     

Smoking and the risk of breast cancer among carriers of BRCA mutations

The effect of cigarette smoking on the risk of breast cancer is controversial, although most studies show little or no effect. It has been suggested that smoking may reduce the risk of developing hereditary breast cancer. We completed a case-control study on 1,097 women with breast cancer who were BRCA1 or BRCA2 mutation carriers and 1,097 age-matched controls with a mutation in the same gene but without breast cancer. There were no statistically significant differences between the cases and controls in terms of the number of current and ex-smokers (41.2% and 40.4%, respectively) or the age at smoking commencement (18.2 years and 18.5 years, respectively). There were no statistically significant differences between cases and controls regarding beginning smoking within 5 years of menarche (OR = 1.03; 95% CI 0.83 to l.28) or before the first pregnancy (OR = 1.09; 95% CI = 0.90 to 1.33). In conclusion, contrary to our previous report, smoking does not appear to be a risk factor for breast cancer among carriers of BRCA mutations.     

Association of the C677T polymorphism in the MTHFR gene with breast and/or ovarian cancer risk in Jewish women

The C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with reduced enzyme activity, hyperhomocysteinaemia and increased risk for atherosclerosis in homozygotes. We examined the frequency of this mutation and its association with disease pattern in 491 Jewish women with either sporadic (n=355; 72%) or hereditary (n=136; 28%) breast and/or ovarian cancer and in 69 asymptomatic BRCA1/2 mutation carriers, genotyped for the three predominant Jewish founder BRCA1/2 mutations (185delAG, 5382insC and 6174delT). 677T homozygotes were equally distributed among women with sporadic breast and/or ovarian cancer (71/355; 20.0%) and among BRCA1/2 mutation carriers (43/205; 21.0%) (P=non-significant). 677T homozygotes were equally distributed among women diagnosed with breast cancer prior to (22/122; 18.0%) and after 42 years of age (42/243; 17.3%). Among BRCA1/2 carriers, the rate of 677T homozygotes in manifesting cancer (32/136; 23.5%) and asymptomatic individuals (11/69; 15.9%) was not significantly different. The rate of 677T homozygotes (24/72; 33.3%) was higher (P=0.0026) among women with bilateral breast cancer and those with both breast and ovarian carcinoma than among those with unilateral breast cancer (64/365; 17.5%). Differences in morbidity (one versus multiple breast/ovarian tumours) are mainly attributed to 677T homozygosity and partly to BRCA1/2 mutations. Confirmation of these data, namely, that the 677T allele is significantly more common in cases of bilateral breast cancer or combined breast and ovarian cancer would have important clinical implications.     

Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers in a large cohort of unselected Chinese breast cancer patients

To estimate the cumulative risk of contralateral breast cancer (CBC) in BRCA1/2 carriers in a large cohort of unselected Chinese breast cancer patients. Our study comprised 9,401 unselected Chinese breast cancer patients and BRCA1/2 germline mutations were determined in all patients. After a median follow-up of 5.7 years, 181 patients developed CBC in this cohort. Compared to noncarriers, BRCA1 and BRCA2 carriers had a 4.52-fold (95% CI, 2.63–7.76) and 5.54-fold (95% CI, 3.51–8.74) increased risk of CBC, respectively. The 10-year cumulative risk of CBC was 15.5% (95% CI, 9.9–24.2) for BRCA1 carriers, 17.5% (95% CI, 10.9–28.0) for BRCA2 carriers and 3.2% (95% CI, 2.5–4.1) for noncarriers. Younger age at first breast cancer diagnosis was significantly associated with an increased 10-year risk of CBC for BRCA1 carriers (≤40 years vs. >40 years: 21.5% vs. 11.9%, unadjusted hazard ratio [HR] = 2.51, 95% CI, 1.03–6.15, p = 0.044), but not for BRCA2 carriers and noncarriers. The 10-year cumulative CBC risk was significantly higher in both BRCA1 and BRCA2 carriers who had a family history of breast cancer than in those who did not (BRCA1: 27.5% vs. 9.4%, adjusted HR = 2.64, 95% CI, 1.01–6.97, p = 0.049; BRCA2: 27.1% vs. 12.8%, adjusted HR = 2.29, 95% CI, 1.04–5.06, p = 0.040). In conclusion, the risk of CBC was a substantial high in BRCA1/2 carriers in unselected Chinese breast cancer patients, and CBC risk is much more remarkable in both BRCA1 and BRCA2 carriers who had a family history of breast cancer. Younger age at first breast cancer diagnosis also enhanced CBC risk in BRCA1 carriers.     

Consanguinity decreases risk of breast cancer--cervical cancer unaffected.

Marriages between third-degree and more distant relatives are common in many parts of the world. Offspring of consanguineous parents have increased morbidity and mortality related to recessive gene disorders. In a population with a high frequency of consanguinity, we examined the frequency of breast cancer (related in part to tumour genes) and cervical cancers (related to virus infection) among offspring of consanguineous and non-consanguineous parents. Study was done prospectively in the United Arab Emirates. Selected were married female citizens, ages 40-65, who attended 12 primary health care clinics for whatever reason. In a face-to-face interview, subjects were asked: (a) about consanguineous marriages in family; (b) if they have or have had breast or cervical cancer; (c) about family history of cancer, cancer screening and other parameters. Tumour diagnosis was confirmed by review of medical records. Of 1750 women invited into study, 1445 (79%) could be used in analysis. Among 579 (40%) women of consanguineous and 866 (60%) of non-consanguineous parents there were 24 and 54 with breast cancer, respectively (RR = 0.66, CI 0.42 - 1.06). In the 40 to 50 age group, breast cancer reported 13 of 446 women of consanguineous and 37 of 633 of non-consanguineous parents (RR = 0.50, Cl 0.27 - 0.93). Cervical cancer had 15 women in consanguineous and 32 in non-consanguineous group (RR = 0.70, Cl 0.38 - 1.28). Number of families with history of breast cancer in consanguineous and non-consanguineous group was 21 and 23, respectively (P = 0.29). The cancer screening rates and other variable values had fairly balanced distribution between the 2 groups. Having consanguineous parents decreases the risk of breast cancer especially in younger women, risk of cervical cancer being unaffected.     

Management of familial breast cancer risk

Women who are members of breast cancer families are at increased risk for breast cancer. The cloning of BRCA1 and BRCA2 has made it possible to identify mutation carriers within some of these families. Management of breast cancer risk in these families, which presents enormous challenges to patients and clinicians, is addressed. Management should begin with a full evaluation of the patient, including construction of a three-generation pedigree, ascertainment of non-genetic factors that may impact on risk, information on previous and current breast health, practice of and attitudes toward screening, and the psychosocial impact of family history on the individual. Patient priorities in risk management should be explicitly reviewed; these may include survival, cancer prevention, breast preservation, optimization of quality of life or minimization of disruption of day-to-day activities. Approaches to risk management involve screening (usually considered the mainstay), anti-estrogens, prophylactic surgery and/or lifestyle modifications. Specific gene therapy may become available in the future. Management decisions should be individualized to reflect risk levels and patient priorities and goals, within bounds that are medically and scientifically reasonable. An explicit examination of different time-frames (1, 5, 10 years) is recommended given the rapid evolution of knowledge in this area.     

BRCA1/BRCA2 mutation status and clinical-pathologic features of 108 male breast cancer cases from Tuscany: a population-based study in central Italy

Background Male breast cancer (MBC) is a rare and scarcely investigated disease. The strongest genetic risk factor for MBC is represented by inherited BRCA2 mutations, whereas the association between MBC and BRCA1 mutations is less clear. MBC appears to be biologically similar to breast cancer in females, however the phenotypic characteristics of BRCA1/2-related MBCs are not yet well elucidated. Objective To investigate the genetic and phenotypic characteristics of MBC in a large and well-characterized population-based series of 108 MBCs from Tuscany (Central Italy) and to evaluate associations between BRCA1/BRCA2 mutation status and clinical-pathological features including breast/ovarian cancer first-degree family history, tumor histology and grade, proliferative activity, estrogen/progesterone receptors (ER/PR) and epidermal growth factor receptor 2 (HER2) expression. Results BRCA1/BRCA2 mutations were identified in ten MBCs, in particular, two cases (1.9%) carried BRCA1 and eight cases (7.4%) carried BRCA2 mutations. The same BRCA1 mutation (3347delAG) was detected in two unrelated MBC cases. Three novel BRCA2 pathogenic mutations were found. Statistically significant associations emerged between BRCA2-related tumors and absence of PR expression (P = 0.008), HER2 over-expression (P = 0.002) and high tumor grade (P = 0.005). Conclusions Here, we (i) reported that in our population about 9% of MBC cases are accounted for by BRCA1/BRCA2 mutations; (ii) enlarged the BRCA2 mutational spectrum and (iii) characterized a specific phenotype associated with BRCA2-related MBCs suggestive of aggressive behavior. Overall, our results may have important implications on clinical management for this rare disease.     

BRCA1/BRCA2 rearrangements and CHEK2 common mutations are infrequent in Italian male breast cancer cases

Male breast cancer (MBC) is a rare and poorly known disease. Germ-line mutations of BRCA2 and, to lesser extent, BRCA1 genes are the highest risk factors associated with MBC. Interestingly, BRCA2 germ-line rearrangements have been described in high-risk breast/ovarian cancer families which included at least one MBC case. Germ-line mutations of CHEK2 gene have been also implicated in inherited MBC predisposition. The CHEK2 1100delC mutation has been shown to increase the risk of breast cancer in men lacking BRCA1/BRCA2 mutations. Intriguingly, two other CHEK2 mutations (IVS2+1G>A and I157T) and a CHEK2 large genomic deletion (del9-10) have been associated with an elevated risk for prostate cancer. Here, we investigated the contribution of BRCA1, BRCA2 and CHEK2 alterations to MBC predisposition in Italy by analysing a large series of MBC cases, unselected for breast cancer family history and all negative for BRCA1/BRCA2 germ-line mutations. A total of 102 unrelated Italian MBC cases were screened for deletions/duplications of BRCA1, BRCA2 and CHEK2 by multiplex ligation-dependent probe amplification. No BRCA1, BRCA2 and CHEK2 genomic rearrangements, including the CHEK2 del9-10, were found in the series analysed. Furthermore, none of the MBC cases and 263 male population controls, also included in this study, carried the CHEK2 1100delC, IVS2+1G>A and I157T common mutations. Overall, our data suggest that screening of BRCA1/2 rearrangements is not advantageous in MBC cases not belonging to high-risk breast cancer families and that common CHEK2 mutations play an irrelevant role in MBC predisposition in Italy.     

High detection rate for BRCA2 mutations in male breast cancer families from North West England

33 families with a history of male breast cancer aged 60 or less or with a family history of male and female breast cancer were screened for the presence of BRCA2 mutations. 12 pathogenic BRCA2 mutations were identified (36%) in samples from an affected family member. All mutations segregated with disease where it was possible to check. Of the 14 families fulfilling BCLC criteria, 9 (64%) had mutations whilst only 3/16 (19%) of male breast cancer patients with less significant female breast cancer family history having a mutation. All 3 families with ovarian cancer and 3 families with multiple male breast cancer cases had BRCA2 mutations. These data are a further guide to how to prioritise samples for BRCA2 mutation analysis.     

Age at menarche and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

Age at menarche is a strong and consistent predictor of breast cancer risk in the general population, but has not been well studied in women with a family history of breast cancer. We conducted this study to examine whether the presence of a deleterious BRCA1 or BRCA2 mutation influences age at menarche and to investigate whether or not there is an association between age at menarche and the risk of breast cancer in BRCA1 or BRCA2 mutation carriers. The presence of a deleterious BRCA1 or BRCA2 mutation did not appear to influence a woman’s age at menarche. A matched case–control study was conducted on 1311 pairs of women who have been identified to be carriers of a deleterious mutation in either the BRCA1 (n = 945 pairs) or the BRCA2 gene (n = 366 pairs). Information about age at menarche was derived from a questionnaire routinely administered to carriers of a mutation in either gene. Among women who carried a deleterious BRCA1 mutation, age at menarche was inversely associated with the risk of breast cancer (p trend = 0.0002). This association was not observed among BRCA2 mutation carriers (p trend = 0.49). Compared with BRCA1 carriers whose age at menarche was ≤11 years, women with a menarcheal age between 14 and 15 years old had a 54% reduction in risk (OR = 0.46; 95% CI 0.30–0.69). This study implicates early age at menarche as a determinant of breast cancer among women with a BRCA1 mutation. * Address correspondence to: Steven A. Narod, Centre for Research in Women’s Health, University of Toronto, 790 Bay Street, Room 750, 7th Floor, Women’s College Hospital, Toronto, Ontario, M5G 1N8, Canada. Ph.: +1-416-351-3765; Fax: +1-416-351-3767; E-mail: steven.narod@swchsc.on.ca     

Identification of a novel BRCA1 large genomic rearrangement in a Spanish breast/ovarian cancer family

Background Alterations in BRCA1 gene are responsible for the majority of hereditary breast and/or ovarian cancers. However, the frequency of detected germline mutations is lower than expected by linkage analysis. Standard PCR-based screening methods are mainly used for detecting mutations, but the large genomic rearrangements are commonly overlooked. The purpose of this study was to confirm and characterize a novel deletion identified in BRCA1 gene which has not yet been reported to date. Methods Multiplex ligation-dependent probe amplification was used to analyze BRCA1 rearrangements in 255 unrelated index patients with familial breast and/or ovarian cancer negative for BRCA1/BRCA2 mutations studied in Program of Genetic Counselling on Cancer of Valencia Community (Spain). The breakpoints of detected novel rearrangement were characterized by sequencing. Results and discussion Five different rearrangements in the BRCA1 gene were identified in five unrelated index patients out of the 225 (2%). We found four large genomic rearrangements already described consisting in a 1A/1B and 2 deletion; deletion of exons 5–7; deletion of exons 8–13; exon 20 deletion. Additionally, we found the novel g.8097_22733del14637 deletion that encompasses exons 3–5. This deletion affects the RING domain of the BRCA1 protein and it is suggestive of having a negative impact on its function. Conclusion The new mutation here reported broadens the mutational spectrum of large rearrangements. Furthermore, the five large rearrangements found in patients non-carriers of BRCA1/BRCA2 mutations reinforce the need of studying BRCA1 large genomic rearrangements in genetic counselling programs.     

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.     

Japanese late-onset breast cancer families: Their clinicopathological characteristics and absence ofBRCA1 andBRCA2 germline mutations

BACKGROUND: The causes and pathologic and prognostic phenotypes of late-onset familial breast cancers are still unknown. The purpose of this study was to document the clinicopathological features of late-onset familial breast cancers using genetic testing ofBRCA1 andBRCA2. METHODS: We analyzed 11 breast cancers from 10 patients from 8 Japanese late-onset Breast cancer families. RESULTS: The average age of the patients was55 years (range 43 to 89). Bilateral occurrence was noted in 2 patients (8%). All the tumors were invasive ductal carcinomas, except for 1 case of invasive lobular carcinoma. Tumor size ranged from 0.8 cm to 7.8 cm (median 2.3 cm) and lymph node metastasis occurred in 6 of the 11 patients (55%). Six (55%) of the 11 tumors were histologically grade 2 and 5 (45%) were histologically grade 3. Estrogen receptor (ER) positivity was 80% (8/10). Overexpression of c-erbB-2 and p53 protein was detected in 18% (2/11) and 9% (1/11) of the tumors, respectively. Five patients from 4 families received genetic testing but all were negative forBRCA1 andBRCA2 germline mutations. All the patients were alive after a median follow-up period of 32 months, except for 1 patient. CONCLUSIONS: In this study, no germline mutations ofBRCA1 orBRCA2 were detected. However, there was a tendency towards ER-positive tumors, but the positivity of p53 protein was considered to be lower then that of sporadic tumors.     

Prevalence of the BRCA1 founder mutation c.5266dupin Brazilian individuals at-risk for the hereditary breast and ovarian cancer syndrome

About 5-10% of breast and ovarian carcinomas are hereditary and most of these result from germline mutations in the BRCA1 and BRCA2 genes. In women of Ashkenazi Jewish ascendance, up to 30% of breast and ovarian carcinomas may be attributable to mutations in these genes, where 3 founder mutations, c.68_69del (185delAG) and c.5266dup (5382insC) in BRCA1 and c.5946del (6174delT) in BRCA2, are commonly encountered. It has been suggested by some authors that screening for founder mutations should be undertaken in all Brazilian women with breast cancer. Thus, the goal of this study was to determine the prevalence of three founder mutations, commonly identified in Ashkenazi individuals in a sample of non-Ashkenazi cancer-affected Brazilian women with clearly defined risk factors for hereditary breast and ovarian cancer (HBOC) syndrome. Among 137 unrelated Brazilian women from HBOC families, the BRCA1c.5266dup mutation was identified in seven individuals (5%). This prevalence is similar to that encountered in non-Ashkenazi HBOC families in other populations. However, among patients with bilateral breast cancer, the frequency of c.5266dup was significantly higher when compared to patients with unilateral breast tumors (12.1% vs 1.2%, p = 0.023). The BRCA1 c.68_69del and BRCA2 c.5946del mutations did not occur in this sample. We conclude that screening non-Ashkenazi breast cancer-affected women from the ethnically heterogeneous Brazilian populations for the BRCA1 c.68_69del and BRCA2 c.5946del is not justified, and that screening for BRCA1c.5266dup should be considered in high risk patients, given its prevalence as a single mutation. In high-risk patients, a negative screening result should always be followed by comprehensive BRCA gene testing. The finding of a significantly higher frequency of BRCA1 c.5266dup in women with bilateral breast cancer, as well as existence of other as yet unidentified founder mutations in this population, should be further assessed in a larger well characterized high-risk cohort.     

Surveillance of women at increased risk of breast cancer using mammography and clinical breast examination: further evidence of benefit

Women with a significant family history of breast cancer are generally offered early surveillance by mammography and often clinical breast examination (CBE). The evidence base for surveillance has been questioned. We reviewed its effectiveness in terms of tumour size, lymph node status and survival in 7,475 women seen over a 22-year period in the Manchester Family History Clinic. We diagnosed 139 invasive and 26 in situ breast cancers. Seventy-six percent of the invasive cancers were screen detected, 65% node negative and 71% <2 cm in diameter at diagnosis. Twenty-one tumours were BRCA1 positive and were significantly more likely to be grade 3, ER/PR negative (p < 0.0001) and have a poorer survival. CBE contributed to 30% of cancer diagnoses and was responsible for discovery of nine mammographically occult tumours. The cost per quality life year was estimated at ￡13,080 for tumours detected by CBE and not by mammography. We conclude that screening by annual mammography and CBE between age 35-50 years and 18 monthly from 50 to 60 years may diagnose breast cancer in a less advanced state in terms of size and node status compared with symptomatic cancers and, apart from BRCA1 carriers, is likely to contribute to improved long-term outcome compared with no surveillance.