Revisiting breast cancer patients who previously tested negative for BRCA mutations using a 12-gene panel.

PURPOSE: BRCA mutations contribute to about 20% of all hereditary breast cancers. With full-genome sequencing as the emerging standard for genetic testing, other breast cancer susceptibility genes have been identified and may collectively contribute to up to 30% of all hereditary breast cancers. We re-assessed women who had previously tested negative for a BRCA mutation when outdated techniques were used, and discuss the implications of identifying a mutation several years after initial genetic testing. METHODS: We evaluated the prevalence of mutations in 12 breast cancer susceptibility genes (including BRCA1 and BRCA2) in 190 breast cancer patients with a strong family history of breast cancer. These women had previously tested negative for mutations in the large coding exons of BRCA1 and BRCA2 using the protein truncation test (PTT) between the years of 1996 and 2013. RESULTS: We identified pathogenic mutations in 17 of 190 (9%) women. Six mutations were detected in BRCA1 (n = 2) and BRCA2 (n = 4). Eleven mutations were found in other breast cancer susceptibility genes including CHEK2 (n = 5), PALB2 (n = 2), BLM (n = 2), ATM (n = 1) and TP53 (n = 1). CONCLUSION: Among 190 breast cancer patients with a family history of the disease, and who previously received a negative result for BRCA mutations using the PTT, 17 (9%) women were found to carry a high-risk pathogenic mutation in a breast cancer susceptibility gene. Six of these women were BRCA mutation carriers who were missed previously. These findings support the rationale for updated genetic testing in patients who tested BRCA mutation negative using outdated techniques.

A high frequency of PALB2 mutations in Jamaican patients with breast cancer.

PURPOSE: Jamaica is an island nation with one of the highest breast cancer incidence rates in the Caribbean (40/100,000 per year). The contribution of cancer susceptibility gene mutations to the burden of breast cancer in Jamaica has not yet been explored. We sought to determine the prevalence of germline mutations in BRCA1, BRCA2, and PALB2 in 179 unselected Jamaican women with breast cancer. METHODS: We sequenced the entire coding regions of BRCA1, BRCA2, and PALB2 for all the study subjects. RESULTS: Overall, 8 of 179 patients (4.5%) had a mutation in one of the three genes: one in BRCA1, two in BRCA2, and five in PALB2. CONCLUSIONS: These data suggest that in addition to BRCA1 and BRCA2, PALB2 should be included in genetic testing for breast cancer patients in Jamaica.

Activation of anti-oxidant Nrf2 signaling by substituted trans stilbenes.

Nrf2, which is a member of the cap'n'collar family of transcription factors, is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. The importance of inflammation and oxidative stress in many chronic diseases supports the concept that activation of anti-oxidant Nrf2 signaling may have therapeutic potential. A number of Nrf2 activators have entered into clinical trials. Nrf2 exists in the cytosol in complex with its binding partner Keap1, which is a thiol-rich redox-sensing protein. In response to oxidative and electrophilic stress, select cysteine residues of Keap1 are modified, which locks Keap1 in the Nrf2-Keap1 complex and allows newly synthesized Nrf2 to enter the nucleus. Numerous Nrf2-activating chemicals, including a number of natural products, are electrophiles that modify Keap1, often by Michael addition, leading to activation of Nrf2. One concern with the design of Nrf2 activators that are electrophilic covalent modifiers of Keap1 is the issue of selectivity. In the present study, substituted trans stilbenes were identified as activators of Nrf2. These activators of Nrf2 are not highly electrophilic and therefore are unlikely to activate Nrf2 through covalent modification of Keap1. Dose-response studies demonstrated that a range of substituents on either ring of the trans stilbenes, especially fluorine and methoxy substituents, influenced not only the sensitivity to activation, reflected in EC50 values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2. The stilbene backbone appears to be a privileged scaffold for development of a new class of Nrf2 activators.

A Survey of BRCA1, BRCA2, and PALB2 mutations in women with breast cancer in Trinidad and Tobago.

The mortality rate from breast cancer in the nation of Trinidad and Tobago is among the highest of any country in the Caribbean region. The contribution of inherited gene mutations to the burden of breast cancer in Trinidad and Tobago has not been studied. We examined the prevalence of mutations in three susceptibility genes (BRCA1, BRCA2, and PALB2) in breast cancer patients in Trinidad and Tobago. We studied 268 unselected breast cancer patients from Trinidad and Tobago and looked for mutations across the entire coding sequences of BRCA1, BRCA2, and PALB2. Overall, 28 of 268 patients (10.4 %) had a mutation in one of the three genes, including 15 in BRCA1, ten in BRCA2, two in PALB2, and one in both BRCA2 and PALB2. There were 25 different mutations identified; of these, four mutations were seen in two patients each. Given the high prevalence of mutations, it is reasonable to offer genetic testing for these three genes to all breast cancer patients in Trinidad and Tobago.

Prevalence of BRCA1 and BRCA2 mutations in unselected breast cancer patients from medellín, Colombia.

BACKGROUND: Approximately 5% of all breast cancers can be attributed to a mutation in the BRCA1 or BRCA2 gene. The genetic component of breast cancer in Colombia has been, for the most part, studied on cases from the Bogota region. Five different founder mutations were in two studies of breast cancer patients in the Bogota region. It is important that the frequency of mutations be established among unselected cases of breast cancer of other regions of Colombia in order to estimate the genetic burden of this cancer in Colombia and to plan genetic services. The aim of this study was to establish the mutation frequencies of the BRCA genes in breast cancer patients unselected for family history or age, from Medellin, Colombia. METHODS: We enrolled 280 unselected women with breast cancer from a large public hospital in Medellin, Colombia. A detailed family history from each patient and a blood sample was obtained and processed for DNA analysis. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques including a panel of recurrent Hispanic BRCA mutations which consists of fifty BRCA1 mutations and forty-six BRCA2 mutations, including the five recurrent Colombian BRCA mutations. All mutations were confirmed by direct sequencing. RESULTS: Genetic testing was successfully completed for 244 of the 280 cases (87%). Among the 244 cases, three deleterious mutations were identified (two in BRCA1 and one in BRCA2) representing 1.2% of the total. The average age of breast cancer in the mutation-positive cases was 34 years. The two BRCA1 mutations were known founder mutations (3450del4 in exon 11 and A1708E in exon 18). The BRCA2 mutation was in exon 11 (5844del5) and has not been previously reported in individuals of Colombian descent. Among the three mutation-positive families was a breast cancer family and two families with no history of breast or ovarian cancer. CONCLUSION: The frequency of BRCA mutations in unselected breast cancer cases from the Medellin region of Colombia is low and is approximately 1.2%.

Early onset breast cancer in a registry-based sample of African-american women: BRCA mutation prevalence, and other personal and system-level clinical characteristics.

Young Black women are disproportionately afflicted with breast cancer, a proportion of which may be due to BRCA1 and BRCA2 (BRCA) gene mutations. In a sample of Black women with early onset breast cancer, we evaluated BRCA mutations and explored personal and system-level clinical characteristics. Black women diagnosed with invasive breast cancer (age ≤50) were recruited through the state cancer registry. Participants completed a questionnaire, genetic counseling and BRCA testing. Of the 48 women who consented to study participation, 46 provided a usable biologic specimen for BRCA testing. The overall prevalence of BRCA mutations and variants of uncertain significance (VUS) in participants was 6.5% and 34.8%, respectively. Of these, only 14 were referred for genetic counseling prior to study enrollment. Overall, those participants who chose to undergo bilateral mastectomy had a higher number of relatives with breast and ovarian cancer (p = 0.024) and a higher household income (p = 0.009). BRCA mutation prevalence and the high prevalence of VUS in participants are consistent with prior studies. Furthermore, clinical factors such as family history and financial means may influence type of surgery recommended and chosen, at both the provider and patient level, respectively. Finally, the limited number of patients referred for genetic counseling prior to surgical treatment for breast cancer may represent a missed clinical opportunity to inform surgical decisions.

Inhibition of lactate dehydrogenase A induces oxidative stress and inhibits tumor progression.

As the result of genetic alterations and tumor hypoxia, many cancer cells avidly take up glucose and generate lactate through lactate dehydrogenase A (LDHA), which is encoded by a target gene of c-Myc and hypoxia-inducible factor (HIF-1). Previous studies with reduction of LDHA expression indicate that LDHA is involved in tumor initiation, but its role in tumor maintenance and progression has not been established. Furthermore, how reduction of LDHA expression by interference or antisense RNA inhibits tumorigenesis is not well understood. Here, we report that reduction of LDHA by siRNA or its inhibition by a small-molecule inhibitor (FX11 [3-dihydroxy-6-methyl-7-(phenylmethyl)-4-propylnaphthalene-1-carboxylic acid]) reduced ATP levels and induced significant oxidative stress and cell death that could be partially reversed by the antioxidant N-acetylcysteine. Furthermore, we document that FX11 inhibited the progression of sizable human lymphoma and pancreatic cancer xenografts. When used in combination with the NAD(+) synthesis inhibitor FK866, FX11 induced lymphoma regression. Hence, inhibition of LDHA with FX11 is an achievable and tolerable treatment for LDHA-dependent tumors. Our studies document a therapeutical approach to the Warburg effect and demonstrate that oxidative stress and metabolic phenotyping of cancers are critical aspects of cancer biology to consider for the therapeutical targeting of cancer energy metabolism.

The HOXB13 p.Gly84Glu mutation is not associated with the risk of breast cancer.

Recently, the HOXB13 gene has been shown to be a susceptibility gene for prostate cancer. HOXB13 is overexpressed in breast cancer tissues and HOXB13 expression in combination with low expression of IL17BR is predictive for a tamoxifen response in ER-positive breast cancers. Based on observations, we hypothesized that the HOXB13 p.Gly84Glu mutation might be associated with breast cancer risk. We genotyped this mutation in the germline DNA of 4,037 women with breast cancer (including 1,082 familial cases) and in 2,762 controls from Canada and Poland. Seven heterozygous carriers of the HOXB13 p.Gly84Glu mutation were found in the cases (0.17 %) compared to four carriers among the controls (0.14 %; OR = 1.2, 95 % CI = 0.34-4.1, p = 1.0). Only one of the seven carriers had a family history of breast cancer. This study does not support the hypothesis that women who carry the HOXB13 Gly84Glu mutation are at increased risk of breast cancer.

The BRCA2 c.9004G>A (E2002K) [corrected] variant is likely pathogenic and recurs in breast and/or ovarian cancer families of French Canadian descent.

Specific BRCA1 and BRCA2 mutations recur in French Canadian breast and/or ovarian cancer families because of common ancestors, facilitating carrier detection in this population. We recently reported a BRCA2 c.9004G>A variant of unknown clinical significance in two French Canadian breast cancer families. It confers a E3002K alteration in the conserved C-terminus domain of BRCA2, and has been reported in non-French Canadian cancer families. Seven variant positive French Canadian families have since been identified by mutation screening of referrals to hereditary cancer clinics. In this article, we describe the cancer phenotypes of these families and further assess the contribution of this variant in the French Canadian population. We screened index breast cancer cases from 58 cancer families with at least three confirmed cases of breast and/or ovarian cancer and 960 breast cancer cases (48 years mean age) not selected for family history of cancer that were previously found not to carry the most common BRCA1 and BRCA2 mutations reported in this population. The index variant-positive cases from each family had breast cancer between the ages of 35-55 years (43 years mean age); and reported close relatives with breast cancer diagnoses between the ages of 28-84 years (57 years mean age). Three families had ovarian or peritoneal cancers. BRCA2-associated cancers, such as bladder, esophagus, pancreas, prostate, and thyroid cancers also occurred in these families. One c.9004G>A carrier also harbored the PALB2 c.2323C>T (Q775X) mutation found to recur in French Canadian breast cancer cases. No new BRCA2 variant carriers were identified in mutation screens. The absence of BRCA2 c.9004G>A carriers in the breast cancer cases not selected for family history contrasts with familial cases, supporting a pathogenic status for this variant and addition to the existing common BRCA1 and BRCA2 mutation-screening panel for French Canadian breast and/or ovarian cancer families.

BRCA1 and BRCA2 mutations among ovarian cancer patients from Colombia.

OBJECTIVE: The contribution of BRCA1 and BRCA2 mutations to ovarian cancer in Colombia has not yet been explored. Five founder mutations have been identified in two previous studies of breast cancer patients in the Bogota region [1,2]. It is important that the frequency of mutations be established among unselected cases of ovarian cancer in order to estimate the genetic burden of this cancer in Colombia and to plan genetic and preventive services. METHODS: We enrolled 100 unselected women with ovarian cancer from the Bogota region, and from northern and southern central regions of Colombia. A detailed family history was obtained from each patient and a blood sample was processed for DNA analysis. DNA quality was adequate for BRCA testing for 96 women. Mutations in BRCA1 and BRCA2 were sought using a Hispanic BRCA mutation testing panel. All mutations were confirmed by direct sequencing. RESULTS: Fifteen mutations were identified (two in BRCA2 and thirteen in BRCA1) representing 15.6% of the total (95% CI: 7.8% to 21.3%). Among the 15 mutation-positive families there were nine breast-ovarian cancer families, one gastric cancer family, one prostate cancer family, three uterine cancer families, and one family with no history of cancer. A single founder mutation in BRCA1 (3450del4) was seen in 11 patients. CONCLUSION: In summary, BRCA1 founder mutations are common in Colombian women with ovarian cancer. Approximately 11.5% of all ovarian cancer cases in the Bogota region are attributable to a single BRCA1 founder mutation.

Clinical impact of unclassified variants of the BRCA1 and BRCA2 genes.

Women who carry a pathogenic mutation in BRCA1 or BRCA2 have high risks of developing breast and ovarian cancers. The functional effect of many missense variants on BRCA1 and BRCA2 protein function is not known. Here, the authors construct a historical cohort of 4030 female first-degree relatives of 1345 unselected patients with ovarian cancer who have been screened for BRCA1 and BRCA2 mutations. The authors compared the risks by the age of 80 years for all cancers combined in female first-degree relatives of women with a pathogenic mutation, women with a variant of unknown significance (unclassified variant) and non-carriers. The cumulative risk of cancer among the relatives of patients with a pathogenic mutation was much higher than the risk in relatives of non-carriers (50.2% vs 28.5%; HR=2.87, p<10(-4)). In contrast, the cumulative risk of cancer among relatives of patients carrying an unclassified variant was similar to the risk of cancer for relatives of non-carriers (27.6% vs 28.5%; HR=1.08, p=0.79). The authors used three different algorithms to predict the pathogenicity of unclassified variants and compared their penetrance with non-carriers. In this sample, only Align Grantham Variation Grantham Deviation appeared to predict penetrance based on first-degree relatives.

Synthesis of benzyl substituted naphthalenes from benzylidene tetralones.

A convenient and efficient synthesis of novel highly substituted dimethoxybenzylnaphthalenes, which are precursors to several dihydroxynaphthoic acids, is described. The approach involves the use of aldol chemistry to provide a number of benzylidene tetralones, which are converted to the target naphthalenes in three steps, with good to excellent yields. Grignard reaction of intermediate benzyl tetralones provided 1-substituted benzyl naphthalenes. The reported synthesis is flexible and scalable and provides access to naphthalenes having a variety of substitution patterns. These benzyl substituted naphthalenes are being converted to naphthoic acids and the bioactivities of these compounds are currently being investigated.

A high prevalence of BRCA1 mutations among breast cancer patients from the Bahamas.

The Bahamas is a group of islands in the Caribbean with a high incidence of early onset breast cancer. In isolated populations, the identification of founder mutations in cancer predisposing genes may facilitate genetic testing and counseling. To date, six distinct BRCA1 mutations have been found in patients from cancer families from the Bahamas. The frequencies of these mutant alleles have not been measured in a large series of unselected breast cancer patients from Bahamas. We studied 214 Bahamian women with invasive breast cancer, unselected for age or family history of cancer. All patients were screened for six mutations in the BRCA1 gene that have previously been reported in cancer patients from the Bahamas. A mutation was identified in 49 of the 214 breast cancer patients (23%). The mutation frequency was particularly high in women diagnosed before age 50 (33%) in women with a first-degree relative with breast or ovarian cancer (41%) and in women with bilateral breast cancer (58%). Approximately 23% of unselected cases of breast cancer in the Bahamian population are attributable to a founder mutation in the BRCA1 gene-this is the highest reported mutation prevalence for any country studied to date. Genetic testing for these mutations is advisable for all women diagnosed with breast cancer in the Bahamas.

International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation.

The c.156_157insAlu BRCA2 mutation has so far only been reported in hereditary breast/ovarian cancer (HBOC) families of Portuguese origin. Since this mutation is not detectable using the commonly used screening methodologies and must be specifically sought, we screened for this rearrangement in a total of 5,443 suspected HBOC families from several countries. Whereas the c.156_157insAlu BRCA2 mutation was detected in 11 of 149 suspected HBOC families from Portugal, representing 37.9% of all deleterious mutations, in other countries it was detected only in one proband living in France and in four individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 ± 215 years ago. We further demonstrate significant quantitative differences regarding the production of the BRCA2 full length RNA and the transcript lacking exon 3 in c.156_157insAlu BRCA2 mutation carriers and in controls. The cumulative incidence of breast cancer in carriers did not differ from that of other BRCA2 and BRCA1 pathogenic mutations. We recommend that all suspected HBOC families from Portugal or with Portuguese ancestry are specifically tested for this rearrangement.

Frequencies of BRCA1 and BRCA2 mutations among 1,342 unselected patients with invasive ovarian cancer.

BACKGROUND: The heritable fraction of ovarian cancer exceeds that of any other common adult cancer. Most inherited cases of ovarian cancer are due to a germline mutation in BRCA1 or BRCA2. It is important to have an accurate estimate of the proportion of ovarian cancer patients who carry a mutation and the specific factors which predict the presence of a mutation. METHODS: We tested a population-based series of 1342 unselected patients diagnosed with invasive ovarian cancer between 1995-1999 and 2002-2004 in Ontario, Canada, for germline mutations in BRCA1 and BRCA2. The two genes were tested in their entirety, using a range of techniques, including multiplex ligation-dependent probe amplification (MLPA). RESULTS: Among the 1342 women, 176 women carried a mutation (107 in BRCA1, 67 in BRCA2, and two in both genes) for a combined mutation frequency of 13.3%. Seven deletions were identified using MLPA (3.9% of all detected mutations). The prevalence of mutations was particularly high among women diagnosed in their forties (24.0%), in women with serous ovarian cancer (18.0%) and women of Italian (43.5%), Jewish (30.0%) or Indo-Pakistani origin (29.4%). A mutation was seen in 33.9% of women with a first-degree relative with breast or ovarian cancer and in 7.9% of women with no first-degree relative with breast or ovarian cancer. No mutation was seen in women with mucinous carcinoma. CONCLUSIONS: BRCA1 and BRCA2 mutations are common in women with invasive ovarian cancer. All women diagnosed with invasive non-mucinous ovarian cancer should be considered to be candidates for genetic testing.

Prevalence of BRCA1 and BRCA2 germ line mutations among women with carcinoma of the fallopian tube.

OBJECTIVES: The purpose of this study is to determine the prevalence of BRCA1 and BRCA2 mutations among a large series of women with carcinoma of the fallopian tube. METHODS: Two series of women diagnosed with carcinoma of the fallopian tube were studied. Women identified from the Ontario Cancer Registry who were diagnosed with fallopian tube cancer between 1990 and 1998 and between 2002 and 2004. A second, hospital-based series was identified at Cedars Sinai Medical Centre, Los Angeles, California. These women were diagnosed between 1991 and 2007. Each subject was approached to provide her family history and ethnic background and to provide a blood sample for genetic testing for mutations in the BRCA1 and BRCA2 genes. RESULTS: In total, 108 patients with fallopian tube cancer were recruited (70 from Ontario and 38 from Los Angeles). Thirty-three patients (30.6%) were found to have a deleterious mutation; 23 in BRCA1 (21.3%) and 10 in BRCA2 (9.3%). The prevalence of mutations was 55.6% in Jewish women and was 26.4% in non-Jewish women. A family history of ovarian or breast cancer was positive for 24 women (23.3%); of these, 14 had a mutation (58.3%). Fourteen (14.4%) of the patients had a previous history of breast cancer; of these, 10 (71.4%) had a mutation. 40.3% of the women who were diagnosed with fallopian tube cancer before age 60 had a mutation, compared with 17.4% of the women diagnosed at age 60 and above. CONCLUSIONS: Approximately 30% of women with fallopian tube cancer have a mutation in BRCA1 or BRCA2. The highest frequencies of BRCA mutations were seen in women with fallopian tube cancer diagnosed under age 60, in Jewish women, in women with a family history of breast or ovarian cancer, and in women with a personal history of breast cancer. All patients diagnosed with invasive fallopian tube cancer should be considered candidates for genetic testing.

Synthesis of Hemigossypol and its Derivatives.

Hemigossypol (3), a sesquiterpene natural product, was previously isolated from Gossypium barbadense and was shown to display improved anti-fungal activity compared to gossypol (1), the disesquiterpene dimer of hemigossypol (3). Gossypol exhibits multiple biological activities. In order to study whether hemigossypol and it derivatives retain the various bioactivities of gossypol, we developed a short and convenient synthetic scheme to synthesize hemigossypol. This is the first de novo synthesis of this natural product. In addition derivatives of hemigossypol with various 2,5-alkyl substituents were synthesized. Modification of the synthetic scheme also afforded the natural product hemigossylic lactone (4) and its 2,5-substituted derivatives.

Germline RAP80 mutations and susceptibility to breast cancer.

Most of the breast cancer susceptibility genes identified to date are involved in DNA repair, including BRCA1, BRCA2, PALB2, CHEK2 and BRIP1. RAP80 works upstream of BRCA1 and is essential for the localization of BRCA1 to the site of damaged DNA. To investigate whether or not RAP80 is also a breast cancer susceptibility gene, we sequenced the entire exonic regions of RAP80 in the germline DNA of 152 women with familial breast cancer, who were previously found to be negative for BRCA1 and BRCA2 mutations. No truncating mutation was identified. Eleven potentially deleterious RAP80 variants were identified; these 11 variants were genotyped in 424 more familial cases and in 726 healthy controls. Three novel p.Ala342Thr, p.Met353Thr and p.Tyr575Asp rare missense variants and a novel haplotype composed of two variants in the CpG island (c.-24149G > T and c.-24001A > G) and a variant in the 5'UTR (c.-8A > G) and a variant in the 3'UTR (c.*27A > C) were detected in 26 of 571 (4.6%) individuals with familial breast cancer, compared to 14 of 725 (1.9%) controls (P = 0.01; OR = 2.4, 95% CI = 1.2-5.1). In summary, we did not find truncating mutations of the RAP80 gene to be a cause of familial breast cancer. A novel RAP80 haplotype or rare missense mutations may be associated with a modest increased risk of breast cancer, but this observation needs to be confirmed by additional studies.

The prevalence of BRCA1 mutations among young women with triple-negative breast cancer.

BACKGROUND: Molecular screening for BRCA1 and BRCA2 mutations is now an established component of risk evaluation and management of familial breast cancer. Features of hereditary breast cancer include an early age-of-onset and over-representation of the 'triple-negative' phenotype (negative for estrogen-receptor, progesterone-receptor and HER2). The decision to offer genetic testing to a breast cancer patient is usually based on her family history, but in the absence of a family history of cancer, some women may qualify for testing based on the age-of-onset and/or the pathologic features of the breast cancer. METHODS: We studied 54 women who were diagnosed with high-grade, triple-negative invasive breast cancer at or before age 40. These women were selected for study because they had little or no family history of breast or ovarian cancer and they did not qualify for genetic testing using conventional family history criteria. BRCA1 screening was performed using a combination of fluorescent multiplexed-PCR analysis, BRCA1 exon-13 6 kb duplication screening, the protein truncation test (PTT) and fluorescent multiplexed denaturing gradient gel electrophoresis (DGGE). All coding exons of BRCA1 were screened. The two large exons of BRCA2 were also screened using PTT. All mutations were confirmed with direct sequencing. RESULTS: Five deleterious BRCA1 mutations and one deleterious BRCA2 mutation were identified in the 54 patients with early-onset, triple-negative breast cancer (11%). CONCLUSION: Women with early-onset triple-negative breast cancer are candidates for genetic testing for BRCA1, even in the absence of a family history of breast or ovarian cancer.

Prevalence of BRCA1 and BRCA2 mutations in breast cancer patients from Cuba.

The contribution of BRCA1 and BRCA2 to breast cancer incidence in Cuba has not yet been explored. In order to estimate the proportion of breast cancers due to BRCA1 and BRCA2 mutations in Cuba, and to identify possible Cuban founder mutations, we conducted a study of unselected breast cancer patients from Havana, Cuba. We enrolled 336 women with breast cancer from a large public hospital in the city. A family history of cancer was obtained from each patient and a blood sample was processed for DNA analysis. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques, but all mutations were confirmed by direct sequencing. We were able to successfully complete testing on samples from 307 women. Among these, eight mutations were identified (seven in BRCA2 and one in BRCA1) representing 2.6% of the total, including 10% of familial cases and 10% of cases under age forty. One BRCA2 mutation (c.3394C > T) was found in two women, but no clear example of a founder mutation was identified. In summary, BRCA1 and BRCA2 mutations are not uncommon in Cuban women with breast cancer, but the absence of founder mutations precludes the development of a rapid and inexpensive clinical screening test.