Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer.

BACKGROUND: The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety. PATIENTS AND METHODS: One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015. RESULTS: With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome. CONCLUSION: With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Electronically ascertained extended pedigrees in breast cancer genetic counseling.

A comprehensive pedigree, usually provided by the counselee and verified by medical records, is essential for risk assessment in cancer genetic counseling. Collecting the relevant information is time-consuming and sometimes impossible. We studied the use of electronically ascertained pedigrees (EGP). The study group comprised women (n = 1352) receiving HBOC genetic counseling between December 2006 and December 2016 at Landspitali in Iceland. EGP's were ascertained using information from the population-based Genealogy Database and Icelandic Cancer Registry. The likelihood of being positive for the Icelandic founder BRCA2 pathogenic variant NM_000059.3:c.767_771delCAAAT was calculated using the risk assessment program Boadicea. We used this unique data to estimate the optimal size of pedigrees, e.g., those that best balance the accuracy of risk assessment using Boadicea and cost of ascertainment. Sub-groups of randomly selected 104 positive and 105 negative women for the founder BRCA2 PV were formed and Receiver Operating Characteristics curves compared for efficiency of PV prediction with a Boadicea score. The optimal pedigree size included 3° relatives or up to five generations with an average no. of 53.8 individuals (range 9-220) (AUC 0.801). Adding 4° relatives did not improve the outcome. Pedigrees including 3° relatives are difficult and sometimes impossible to generate with conventional methods. Pedigrees ascertained with data from pre-existing genealogy databases and cancer registries can save effort and contain more information than traditional pedigrees. Genetic services should consider generating EGP's which requires access to an accurate genealogy database and cancer registry. Local data protection laws and regulations have to be addressed.

Air breathing in Magadi tilapia Alcolapia grahami, under normoxic and hyperoxic conditions, and the association with sunlight and reactive oxygen species.

Observations of the Magadi tilapia Alcolapia grahami in hot, highly alkaline Lake Magadi revealed that they air breathe not only during hypoxia, as described previously, but also during normoxia and hyperoxia. Air breathing under these latter conditions occurred within distinct groupings of fish (pods) and involved only a small proportion of the population. Air breathing properties (duration and frequency) were quantified from video footage. Air breathing within the population followed a diel pattern with the maximum extent of pod formation occurring in early afternoon. High levels of reactive oxygen species (ROS) in the water may be an irritant that encourages the air-breathing behaviour. The diel pattern of air breathing in the field and in experiments followed the diel pattern of ROS concentrations in the water which are amongst the highest reported in the literature (maximum daytime values of 2.53 ­ 8.10 µM H2O2). Interlamellar cell masses (ILCM) occurred between the gill lamellae of fish from the lagoon with highest ROS and highest oxygen levels, while fish from a normoxic lagoon with one third the ROS had little or no ILCM. This is the first record of air breathing in a facultative air-breathing fish in hyperoxic conditions and the first record of an ILCM in a cichlid species.

Morphological evaluation of spermatogenesis in Lake Magadi tilapia (Alcolapia grahami): a fish living on the edge.

Spermatogenesis in Lake Magadi tilapia (Alcolapia grahami), a cichlid fish endemic to the highly alkaline and saline Lake Magadi in Kenya, was evaluated using light and transmission electron microscopy. Spermatogenesis, typified by its three major phases (spermatocytogenesis, meiosis and spermiogenesis), was demonstrated by the presence of maturational spermatogenic cells namely spermatogonia, spermatocytes, spermatids and spermatozoa. Primary spermatogonia, the largest of all the germ cells, underwent a series of mitotic divisions producing primary spermatocytes, which then entered two consecutive meiotic divisions to produce secondary spermatocytes and spermatids. Spermatids, in turn, passed through three structurally distinct developmental stages typical of type-I spermiogenesis to yield typical primitive anacrosomal spermatozoa of the externally fertilizing type (aquasperm). The spermatozoon of this fish exhibited a spheroidal head with the nucleus containing highly electron-dense chromatin globules, a midpiece containing ten ovoid mitochondria arranged in two rows and a flagellum formed by the typical 9 + 2 microtubule axoneme. In addition, the midpiece, with no cytoplasmic sheath, appeared to end blindly distally in a lobe-like pattern around the flagellum; a feature that was unique and considered adaptive for the spermatozoon of this species to the harsh external environment. These observations show that the testis of A. grahami often undergoes active spermatogenesis despite the harsh environmental conditions to which it is exposed on a daily basis within the lake. Further, the spermiogenic features and spermatozoal ultrastructure appear to be characteristic of Cichlidae and, therefore, may be of phylogenetic significance.

The BOADICEA model of genetic susceptibility to breast and ovarian cancers: updates and extensions.

Multiple genetic loci confer susceptibility to breast and ovarian cancers. We have previously developed a model (BOADICEA) under which susceptibility to breast cancer is explained by mutations in BRCA1 and BRCA2, as well as by the joint multiplicative effects of many genes (polygenic component). We have now updated BOADICEA using additional family data from two UK population-based studies of breast cancer and family data from BRCA1 and BRCA2 carriers identified by 22 population-based studies of breast or ovarian cancer. The combined data set includes 2785 families (301 BRCA1 positive and 236 BRCA2 positive). Incidences were smoothed using locally weighted regression techniques to avoid large variations between adjacent intervals. A birth cohort effect on the cancer risks was implemented, whereby each individual was assumed to develop cancer according to calendar period-specific incidences. The fitted model predicts that the average breast cancer risks in carriers increase in more recent birth cohorts. For example, the average cumulative breast cancer risk to age 70 years among BRCA1 carriers is 50% for women born in 1920-1929 and 58% among women born after 1950. The model was further extended to take into account the risks of male breast, prostate and pancreatic cancer, and to allow for the risk of multiple cancers. BOADICEA can be used to predict carrier probabilities and cancer risks to individuals with any family history, and has been implemented in a user-friendly Web-based program (http://www.srl.cam.ac.uk/genepi/boadicea/boadicea_home.html).

Breast and ovarian cancer risks to carriers of the BRCA1 5382insC and 185delAG and BRCA2 6174delT mutations: a combined analysis of 22 population based studies.

A recent report estimated the breast cancer risks in carriers of the three Ashkenazi founder mutations to be higher than previously published estimates derived from population based studies. In an attempt to confirm this, the breast and ovarian cancer risks associated with the three Ashkenazi founder mutations were estimated using families included in a previous meta-analysis of populatrion based studies. The estimated breast cancer risks for each of the founder BRCA1 and BRCA2 mutations were similar to the corresponding estimates based on all BRCA1 or BRCA2 mutations in the meta-analysis. These estimates appear to be consistent with the observed prevalence of the mutations in the Ashkenazi Jewish population.

Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case Series unselected for family history: a combined analysis of 22 studies.

Germline mutations in BRCA1 and BRCA2 confer high risks of breast and ovarian cancer, but the average magnitude of these risks is uncertain and may depend on the context. Estimates based on multiple-case families may be enriched for mutations of higher risk and/or other familial risk factors, whereas risk estimates from studies based on cases unselected for family history have been imprecise. We pooled pedigree data from 22 studies involving 8,139 index case patients unselected for family history with female (86%) or male (2%) breast cancer or epithelial ovarian cancer (12%), 500 of whom had been found to carry a germline mutation in BRCA1 or BRCA2. Breast and ovarian cancer incidence rates for mutation carriers were estimated using a modified segregation analysis, based on the occurrence of these cancers in the relatives of mutation-carrying index case patients. The average cumulative risks in BRCA1-mutation carriers by age 70 years were 65% (95% confidence interval 44%-78%) for breast cancer and 39% (18%-54%) for ovarian cancer. The corresponding estimates for BRCA2 were 45% (31%-56%) and 11% (2.4%-19%). Relative risks of breast cancer declined significantly with age for BRCA1-mutation carriers (P trend.0012) but not for BRCA2-mutation carriers. Risks in carriers were higher when based on index breast cancer cases diagnosed at <35 years of age. We found some evidence for a reduction in risk in women from earlier birth cohorts and for variation in risk by mutation position for both genes. The pattern of cancer risks was similar to those found in multiple-case families, but their absolute magnitudes were lower, particularly for BRCA2. The variation in risk by age at diagnosis of index case is consistent with the effects of other genes modifying cancer risk in carriers.

Frequent somatic loss of BRCA1 in breast tumours from BRCA2 germ-line mutation carriers and vice versa.

Breast cancer susceptibility genes BRCA1 and BRCA2 are tumour suppressor genes the alleles of which have to be inactivated before tumour development occurs. Hereditary breast cancers linked to germ-line mutations of BRCA1 and BRCA2 genes almost invariably show allelic imbalance (AI) at the respective loci. BRCA1 and BRCA2 are believed to take part in a common pathway in maintenance of genomic integrity in cells. We carried out AI and fluorescence in situ hybridization (FISH) analyses of BRCA2 in breast tumours from germ-line BRCA1 mutation carriers and vice versa. For comparison, 14 sporadic breast tumours were also studied. 8 of the 11 (73%) informative BRCA1 mutation tumours showed AI at the BRCA2 locus. 53% of these tumours showed a copy number loss of the BRCA2 gene by FISH. 5 of the 6 (83%) informative BRCA2 mutation tumours showed AI at the BRCA1 locus. Half of the tumours (4/8) showed a physical deletion of the BRCA1 gene by FISH. Combined allelic loss of both BRCA1 and BRCA2 gene was seen in 12 of the 17 (71%) informative hereditary tumours, whereas copy number losses of both BRCA genes was seen in only 4/14 (29%) sporadic control tumours studied by FISH. In conclusion, the high prevalence of AI at BRCA1 in BRCA2 mutation tumours and vice versa suggests that somatic events occurring at the other breast cancer susceptibility gene locus may be selected in the cancer development. The mechanism resulting in AI at these loci seems more complex than a physical deletion.

Family history of breast and ovarian cancers and BRCA1 and BRCA2 mutations in a population-based series of early-onset breast cancer.

BACKGROUND: BRCA1 and BRCA2 are the two major susceptibility genes involved in hereditary breast cancer. This study was undertaken to provide reliable population-based estimates of genetic influence and to characterize the nature and prevalence of BRCA1 and BRCA2 germline mutations in early-onset breast cancer. METHODS: In a series comprising all women diagnosed with breast cancer under the age of 41 years in southern Sweden during 1990 through 1995 (n = 262), family history of cancer was evaluated in 95% (n = 250) of the case subjects and germline mutations in BRCA1 and BRCA2 were analyzed in 89% (n = 234). All statistical tests were two-sided. RESULTS: A total of 97 case subjects had at least one first- or second-degree relative with breast or ovarian cancer; 34 (14%; 95% confidence interval [CI] = 9.6% to 18%) cases had at least two first- or second-degree relatives, 22 (8.8%; 95%CI = 5.3% to 12%) had one first-degree relative, and 41 (16%; 95% CI = 12% to 21%) had one second-degree relative with either cancer. If two females affected with breast or ovarian cancer who were related through an unaffected male were also defined as first-degree relatives, then a higher number of case subjects, 120 (48%; 95% CI = 42% to 54%), had at least one first-degree or second-degree relative with breast or ovarian cancer. Sixteen (6.8%; 95% CI = 4.0% to 11%) BRCA1 mutation carriers and five (2.1%; 95% CI = 0.70% to 4.9%) BRCA2 mutation carriers were identified. Among case subjects with one first- or more than one first- or second-degree relative with breast or ovarian cancer, BRCA mutations were more frequent (P<.001) than among the case subjects without this degree of family history. BRCA mutations were also statistically significantly more common among women with bilateral breast cancer than among women with unilateral breast cancer (P =.002). BRCA mutations were more common among younger case subjects than among older ones (P =.0027). CONCLUSIONS: Almost half (48%) of women in southern Sweden with early-onset breast cancer have some family history of breast or ovarian cancer, and 9.0% of early-onset breast cancer cases are associated with a germline mutation in BRCA1 or BRCA2. Mutation carriers were more prevalent among young women, women with at least one first- or second-degree relative with breast or ovarian cancer, and women with bilateral breast cancer.

Gene-expression profiles in hereditary breast cancer.

BACKGROUND: Many cases of hereditary breast cancer are due to mutations in either the BRCA1 or the BRCA2 gene. The histopathological changes in these cancers are often characteristic of the mutant gene. We hypothesized that the genes expressed by these two types of tumors are also distinctive, perhaps allowing us to identify cases of hereditary breast cancer on the basis of gene-expression profiles. METHODS: RNA from samples of primary tumor from seven carriers of the BRCA1 mutation, seven carriers of the BRCA2 mutation, and seven patients with sporadic cases of breast cancer was compared with a microarray of 6512 complementary DNA clones of 5361 genes. Statistical analyses were used to identify a set of genes that could distinguish the BRCA1 genotype from the BRCA2 genotype. RESULTS: Permutation analysis of multivariate classification functions established that the gene-expression profiles of tumors with BRCA1 mutations, tumors with BRCA2 mutations, and sporadic tumors differed significantly from each other. An analysis of variance between the levels of gene expression and the genotype of the samples identified 176 genes that were differentially expressed in tumors with BRCA1 mutations and tumors with BRCA2 mutations. Given the known properties of some of the genes in this panel, our findings indicate that there are functional differences between breast tumors with BRCA1 mutations and those with BRCA2 mutations. CONCLUSIONS: Significantly different groups of genes are expressed by breast cancers with BRCA1 mutations and breast cancers with BRCA2 mutations. Our results suggest that a heritable mutation influences the gene-expression profile of the cancer.

MYB oncogene amplification in hereditary BRCA1 breast cancer.

Comparative genomic hybridization analysis has demonstrated that breast tumors from BRCA1 and BRCA2 germ-line mutation carriers contain a large number of chromosomal copy number gains and losses. A high regional copy number gain at 6q22-q24 was observed in one BRCA1 tumor, and fluorescence in situ hybridization analysis indicated a strong amplification of the MYB oncogene (15 copies of MYB compared with 1 copy of chromosome 6 centromere). Fluorescence in situ hybridization analysis revealed amplification of MYB in 5 (29%) of 17 BRCA1 breast tumors, whereas none of 8 BRCA2 tumors and 13 breast cancer cell lines, and only 2 of 100 sporadic breast tumors exhibited altered MYB copy numbers. Gene amplification resulted in mRNA overexpression as determined by Northern blot and cDNA microarray analysis, and protein overexpression by immunohistochemical staining. We conclude that MYB amplification is infrequent in sporadic breast cancer but common in breast tumors from BRCA1 mutation carriers, suggesting a role of this cell cycle regulator and transcription factor in the progression of some BRCA1 tumors. However, we cannot rule out the significance of other genes in the 6q22-q24 amplicon.

Somatic deletions in hereditary breast cancers implicate 13q21 as a putative novel breast cancer susceptibility locus.

A significant proportion of familial breast cancers cannot be explained by mutations in the BRCA1 or BRCA2 genes. We applied a strategy to identify predisposition loci for breast cancer by using mathematical models to identify early somatic genetic deletions in tumor tissues followed by targeted linkage analysis. Comparative genomic hybridization was used to study 61 breast tumors from 37 breast cancer families with no identified BRCA1 or BRCA2 mutations. Branching and phylogenetic tree models predicted that loss of 13q was one of the earliest genetic events in hereditary cancers. In a Swedish family with five breast cancer cases, all analyzed tumors showed distinct 13q deletions, with the minimal region of loss at 13q21-q22. Genotyping revealed segregation of a shared 13q21 germ-line haplotype in the family. Targeted linkage analysis was carried out in a set of 77 Finnish, Icelandic, and Swedish breast cancer families with no detected BRCA1 and BRCA2 mutations. A maximum parametric two-point logarithm of odds score of 2.76 was obtained for a marker at 13q21 (D13S1308, theta = 0.10). The multipoint logarithm of odds score under heterogeneity was 3.46. The results were further evaluated by simulation to assess the probability of obtaining significant evidence in favor of linkage by chance as well as to take into account the possible influence of the BRCA2 locus, located at a recombination fraction of 0.25 from the new locus. The simulation substantiated the evidence of linkage at D13S1308 (P < 0.0017). The results warrant studies of this putative breast cancer predisposition locus in other populations.

High frequency of multiple melanomas and breast and pancreas carcinomas in CDKN2A mutation-positive melanoma families.

BACKGROUND: : Inherited mutations in the CDKN2A tumor suppressor gene, which encodes the p16(INK4a) protein, and in the cyclin-dependent kinase 4 (CDK4) gene confer susceptibility to cutaneous malignant melanoma. We analyzed families with two or more cases of melanoma for germline mutations in CDKN2A and CDK4 to elucidate the contribution of these gene defects to familial malignant melanoma and to the occurrence of other cancer types. METHODS: : The entire CDKN2A coding region and exon 2 of the CDK4 gene of an affected member of each of 52 families from southern Sweden with at least two cases of melanoma in first- or second-degree relatives were screened for mutations by use of polymerase chain reaction-single-strand conformation polymorphism analysis. Statistical tests were two-sided. RESULTS: : CDKN2A mutations were found in 10 (19%) of the 52 families. Nine families carried an identical alteration consisting of the insertion of arginine at position 113 of p16(INK4a), and one carried a missense mutation, in which the valine at position 115 was replaced with a glycine. The 113insArg mutant p16(INK4a) was unable to bind cdk4 and cdk6 in an in vitro binding assay. Six of the 113insArg families had at least one member with multiple primary melanomas; the 113insArg families also had a high frequency of other malignancies-in particular, breast cancer (a total of eight cases compared with the expected 2.1; P =.0014) and pancreatic cancer (a total of six cases compared with the expected 0.16; P<.0001). Families with breast cancer also had a propensity for multiple melanomas in females, suggesting that a sex-dependent factor may modify the phenotypic expression of CDKN2A alterations. CONCLUSIONS: : Our findings confirm that the majority of CDKN2A-associated melanoma families in Sweden are due to a single founder mutation. They also show that families with the CDKN2A 113insArg mutation have an increased risk not only of multiple melanomas and pancreatic carcinoma but also of breast cancer.

Prognosis and clinical presentation of BRCA2-associated breast cancer.

54 female breast cancer patients from 22 families with BRCA2 germ line mutations from Sweden and Denmark were compared with 214 age- and date of diagnosis-matched controls identified among breast cancer patients from South Sweden. At diagnosis, BRCA2-associated cases were more often node-positive (N+). OR=1.9 (95% confidence interval (CI)=1.0-3.6; P=0.036), and were more often clinical stage IV: OR=4.6 (95% CI=1.3-17; P=0.021) than the controls. Bilateral disease was also more common among the BRCA2-associated cases: OR=2. 4 (95% CI=1.1-5.3; P=0.027). Breast cancer-specific survival (BCSS) was significantly worse among the BRCA2-associated cases: RR=2.0 (95% CI=1.2-3.4; P=0.010). When stage was corrected for in a multivariate analysis, BCSS was no longer significantly worse for the BRCA2-associated cases: RR=1.6 (95% CI=0.85-3.1). The corresponding effect after correction for bilateral disease was: RR=1.8 (95% CI=1.0-3.1; P=0.034). The unfavourable prognosis in BRCA2-associated breast cancer seems, to a great extent, to be a consequence of the higher clinical stage at diagnosis. The increased presence of bilateral cancers appears to have less impact on survival in this group of hereditary breast cancer. Data presented here needs to be taken into account when counselling healthy carriers of BRCA2 germ line mutations.

Frequent amplification of chromosomal region 20q12-q13 in ovarian cancer.

DNA amplification at chromosomal region 20q12-q13, which is common in breast cancer, has recently been described also in ovarian tumors. We studied the amplification of the recently identified candidate oncogenes in this region in 24 sporadic, 3 familial and 4 hereditary ovarian carcinomas, and in 8 ovarian cancer cell lines. High-level amplification of at least one of the five nonsyntenic regions at 20q12-q13.2 was found in 13 sporadic (54%) and in all four hereditary tumors. Typically, two or more distinct amplicons (separated by nonamplified DNA) were found coamplified in various combinations. The regions defined by the AIB1 and PTPN1 genes (at 20q12 and 20q13.1, respectively) were amplified in 25% and 29% of the sporadic tumors, also without simultaneous coamplification of other regions. Amplification of AIB1 (a steroid receptor coactivator gene) was associated with estrogen receptor positivity in sporadic ovarian carcinomas (P = 0.01) and showed a tendency to correlate with poor survival of patients. Of the genes amplified in breast cancer, the BTAK gene was amplified in 21%, the MYBL2 gene in 17%, and the ZNF217 gene in 12.5% of the sporadic tumors. The high frequency of gene amplification at 20q12-q13.2 suggests that the genes amplified therein may play a central role in the pathogenesis of sporadic and hereditary ovarian carcinoma.

BRCA1 and BRCA2 mutations in ovarian cancer: Covariation with specific cytogenetic features.

We analyzed 37 primary invasive carcinomas for BRCA1 and BRCA2 mutations by screening the entire coding regions of both genes. Seven predicted truncating mutations (four in BRCA1 and three in BRCA2) and one novel BRCA1 missense variant (S1542C) were identified (8/37, 22%). Two of the BRCA1 mutations were somatic changes, whereas the remaining three BRCA1 changes and all mutations of BRCA2 were found to be of germline origin. All eight BRCA-positive tumors were serous or seropapillary carcinomas (8/27 serous tumors, 30%), and all but one were poorly differentiated. The correlation between tumor karyotype and BRCA status showed that clonal chromosomal aberrations were present in all BRCA-positive tumors (8/8) compared with 20 of 29 BRCA-negative ones. The most consistently affected region in BRCA-positive tumors was the long arm of chromosome 6; alterations within this arm with a breakpoint in band 6q21 were seen in four of five BRCA1-positive and in two of three BRCA2-positive tumors, but only in four of 20 karyotypically abnormal tumors without BRCA mutations, suggesting that the genetic pathways of tumor progression differ in the two groups. The high frequency of germline BRCA mutations detected in this pilot study (16% of 37 invasive carcinomas) points to the need for more extended analyses of population-based series of patients to determine the true contribution of these predisposing genes to the overall incidence of ovarian cancer in this population.

Somatic genetic alterations in BRCA2-associated and sporadic male breast cancer.

The genetic changes underlying the development and progression of male breast cancer are poorly understood. Germline BRCA2 mutations account for a significant part of male breast cancer, but the majority of patients lack a known inherited predisposition. We recently demonstrated that the progression of breast cancer in female carriers of a germline BRCA1 or BRCA2 mutation follows specific genetic pathways, distinct from each other and from sporadic breast cancer. In the present study, we performed a genome-wide survey by comparative genomic hybridization (CGH) of somatic genetic aberrations in 26 male breast cancers, including five tumors from BRCA2 mutation carriers. BRCA2 tumors exhibited a significantly higher number of chromosomal aberrations than sporadic tumors. The most common alterations in sporadic male breast cancer were +1q (38%), +8q (33%), +17q (33%), -13q (29%), and -8p (24%). In tumors from BRCA2 mutation carriers, the five most common genetic changes were +8q (100%), +20q (100%), +17q (80%), -13q (80%), and -6q (60%). The CGH results in these two groups of male breast cancers are almost identical to those identified in the corresponding sporadic and BRCA2-associated female breast cancers. The results suggest that despite substantial hormonal differences between females and males, similar genetic changes are selected for during tumor progression. Furthermore, the presence of a highly penetrant germline BRCA2 mutation apparently leads to a characteristic somatic tumor progression pathway, again shared between affected male and female mutation carriers.

Incidence of malignant tumours in relatives of BRCA1 and BRCA2 germline mutation carriers.

We investigated cancer incidence between 1958 and 1995 in 1873 individuals belonging to 29 consecutively identified BRCA1 and 20 BRCA2 associated families from Southern Sweden using data from parish and local tax authorities, as well as the Swedish Cancer Registry, Cause of Death Registry and Census Registry. 150 malignant tumours were analysed from 1145 relatives in the BRCA1 families and 87 tumours were analysed from 728 relatives in the BRCA2 families. After excluding index cases which led to the mutation analysis, the incidence for all malignant tumours was significantly increased for both BRCA1- standardised morbidity rate, SMR, 1.98, 95% confidence interval (CI) 1.59-2.45; P < 0.0001 and BRCA2- (SMR 1.79, 95% CI 1.35-2.31; P < 0.0001) associated family members. For women in BRCA1-associated families, the incidence of breast cancer (SMR 3.76, 95% CI 2.29-5.80, P < 0.0001), ovarian cancer (SMR 15.49, 95% CI 9.46-23.92, P < 0.0001), stomach cancer (SMR 5.86, 95% CI 1.60-15.01, P = 0.005) were significantly increased. Amongst men only invasive squamous cell cancer of the skin was significantly increased (SMR 6.02, 95% CI 1.96-14.05, P = 0.002). In BRCA2 associated families, female breast cancer (SMR 3.03, 95% CI 1.61-5.18, P = 0.0005) was increased after exclusion of index cases. If these were included, ovarian cancer (SMR 5.16, 95% CI 1.89-11.24, P = 0.001), invasive cervical cancer (SMR 4.21, 95% CI 1.15-10.79, P = 0.016), male breast cancer (SMR 290.52, 95% CI 125.42-572.43, P < 0.0001), and prostate cancer (SMR 2.21, 95% CI 0.89-4.56, P = 0.042) were significantly increased. The increased risk for ovarian cancer in BRCA2 related families were limited to the cases leading to mutation analysis. Our data suggest that apart from breast and ovarian cancer, the incidence of other cancer types do not appear to be greatly increased in BRCA1- and BRCA2-associated families and does not warrant specific clinical follow-up in carriers.

The effects of silver on intestinal ion and acid-base regulation in the marine teleost fish, Parophrys vetulus.

Exposure to elevated silver (as AgNO3) concentrations (6-9 microM) in seawater was associated with comparably high silver concentrations in the intestinal fluids of the lemon sole (Parophrys vetulus), and a tendency for reduced drinking rate. The effects of silver on intestinal ion and acid-base regulation were studied using in situ perfusion of the intestine. Intestinal net Cl- uptake was reduced from 0.4 to 0.1 and intestinal net Na+ uptake from 0.2 to 0 mmol kg(-1) x h(-1) during silver exposure (9 microM). At the same time, intestinal HCO3- net efflux was reduced from 0.2 to 0.1 mmol kg(-1) x h(-1). Both intestinal Na+ and Cl- uptake and Cl-/HCO3- exchange are thus sensitive to silver, but to different extents. None of the observed effects were reversible during 24 h of recovery. Intestinal water transport was highly variable in vivo in the perfused preparation, and no significant effect of silver exposure was observed. However, in vitro intestine preparations exhibited reduction of intestinal net water flux from 4 to 1 microl cm(-2) x h(-1) during silver exposure together with reduced unidirectional Cl- influx. Reduced water intake and transepithelial water transport in silver-exposed fish resulted in moderate hemoconcentration evident from higher hematocrit values, but not in increased plasma ion levels. The latter could reflect a compensatory response via increased branchial Na+/K+-ATPase levels, observed in silver-exposed fish, indicative of increased branchial ion transport capacity. Impairment of intestinal ion and water transport as a result of silver intake via drinking could be an important part of the fatal cascade of physiological effects observed in marine fish during acute silver exposure.

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.