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Abstract Modifying factors might theoretically determine whether a BRCA1 mutation carrier contracts breast or ovarian cancer. If so, one would expect concordance for breast or ovarian cancer in affected sibships. We identified 64 pairs with cancers where one or both sisters were demonstrated to carry a BRCA1 mutation, and 116 additional constructed pairs in sibships with three or more affected sisters. We analysed concordance for breast and for ovarian cancer both in the complete series and in the 64 sister pairs alone. The results were that concordance for both breast and ovarian cancer in sisters was in keeping with random distribution or multiple and frequent modifying genetic factors. In conclusion, there may be no major modifying factor of expression of BRCA1 mutations. The practical implication of our findings is that previous disease manifestations in close relatives may have no bearing on the first cancer to be expected in a young female mutation carrier.

Abstract Cowden syndrome (multiple hamartoma syndrome, MIM 158350) is an early onset syndrome characterized by multiple hamartomas in the skin, mucous membranes, breast, thyroid and endometrium. Patients with Cowden syndrome have increased risk of breast cancer, thyroid cancer and endometrial cancer. In 1997 germline mutations in PTEN were demonstrated to cause Cowden syndrome. We report the results of diagnostic and predictive testing in all families with Cowden syndrome or suspected Cowden syndrome registered at the Norwegian cancer family clinics. PTEN mutations were found in all six families meeting the clinical criteria for Cowden syndrome, in none of the two families assumed to have Cowden syndrome but not fulfilling the criteria, and in none of the eight families selected in our computerized medical files to have a combination of breast and thyroid cancers. Age-related penetrances for the various neoplasms are given. All families but one were small and de novo mutations were found.

Abstract Penetrances of BRCA1 and BRCA2 mutations have been derived from retrospective studies, implying the possibility of ascertainment biases to influence the results. We have followed women at risk for breast and/or ovarian cancer for two decades, and report the prospectively observed age-related annual incidence rates to contract breast or ovarian cancer for women with deleterious BRCA1 or BRCA2 mutations based on 4830 observation years. Patients were grouped according to mutation, age and having/not having had previous cancer. In women not having had previous cancer and aged 40-59 years, the annual incidence rate to contract breast or ovarian cancer in those having the most frequent BRCA1 founder mutations was 4.0%, for women in this age group and with less frequent BRCA1 mutations annual incidence rate was 5.9%, and for women with BRCA2 mutations 3.5%. The observed figures may be used for genetic counseling of healthy mutation carriers in the respective age groups. The results may indicate that less frequent BRCA1 mutations have higher penetrances than BRCA1 founder mutations.

Abstract Several studies of survival in women with BRCA1 mutations have shown either reduced survival or no difference compared to controls. Programmes for early detection and treatment of inherited breast cancer, have failed to demonstrate a significant improvement in survival in BRCA1 mutation carriers. One hundred and sixty-seven women with disease-associated germline BRCA1 mutations and breast cancer from 1980 to 2001 were identified. Tumour characteristics, treatment given and survival were recorded. A control group comprising three hundred and four women matched for age, time of diagnosis and stage were used to compare survival. BRCA1 mutation carriers were found to have a poorer prognosis, which could be explained by neither the mode of surgical treatment nor the use of adjuvant chemotherapy. BRCA1 mutation carriers with node negative breast cancer had worse overall survival than controls. Our findings confirm the serious prognosis of BRCA1-associated breast cancer even when diagnosed at an early stage, and that type of treatment does not influence prognosis.

Abstract Background Analysis of the chromosomal background upon which a mutation occurs can be used to reconstruct the origins of specific disease-causing mutations. The relatively common BRCA1 mutation, 1135insA, has been previously identified as a Norwegian founder mutation. We performed haplotype analysis of individuals from breast and ovarian cancer families from four different ethnic backgrounds who had been identified as carriers of the BRCA1: 1135insA mutation. Methods Four microsatellite markers (D17S855, D17S1322, D17S1323 and D17S1325) located within or near the BRCA1 gene were genotyped in mutation carriers from 6 families of French Canadian, Italian and Dutch descent. Haplotypes were inferred from the genotype data and compared between these families and with the previously reported Norwegian founder haplotype. Results The 1135insA mutation was found to occur on three distinct haplotype backgrounds. The families from Norway shared a distinct haplotype while the families of French Canadian, Italian, and Dutch descent were found to occur on one of two additional, distinct backgrounds. Conclusion Our results indicate that while the Norwegian haplotype including 1135insA represents an ancient Norwegian mutation, the same mutation has occurred independently in the other populations examined. In centres where targeted mutation testing is performed, exclusively or prior to gene sequencing, our findings suggest that this recurring mutation should be included in targeted mutation panels, irrespective of the ethnic origin of the persons tested.

Mutations in the Breast-Cancer-1 (BRCA1) gene are the major cause of familial breast/ovarian cancer. Among familial breast cancer only, 15–20% have been suggested to have a deleterious mutation in BRCA1. A highly sensitive method (REF-SSCP) was applied to screen the open reading frame and the 5'UTRs of BRCA1 for mutations. The patient cohort comprised 61 unrelated moderate to high risk breast cancer patients from Western-Norway. Only one known deleterious BRCA1 mutation (c.816-817delGT) was found in two of the 61 patients (3.3%). Four haplotypes were established based on nine known single nucleotide polymorphisms. Two patients had a novel deletion (c.-33_-29delAAAAA) in the 5'UTR, and a novel amino acid substitution (L523W) was found in one patient. Size variations analysis in the 5'UTR was repeated in a cohort of 159 unrelated familial breast/ovarian cancer patients and 94 healthy blood donors. Two patients were identified with 5'UTR (c.-30 to -60) variations (CAAAA)_5 and (CAAAA)_7, instead of the (CAAAA)_6-repeat. All of the identified 5'UTR size variations were localized between the start codon and the most stable secondary structures previously proposed for the exon 1b transcript. No such alterations were found among the healthy blood donors but association studies of the 5'UTR variations within the respective families were not conclusive. [ABSTRACT FROM AUTHOR]

BACKGROUND: Surveillance programmes for women at increased genetic risk of breast cancer are being established worldwide but little is known of their efficacy in early detection of cancers and hence reduction in mortality. METHODS: Data were contributed from seven centres participating in the EU Demonstration Programme on Clinical Services for Familial Breast Cancer.  All breast tumours (n = 161) detected prospectively, from the time of enrolment of women in a screening programme, were recorded.  Analysis took account of age at diagnosis, whether tumours were screen-detected or not, their pathological stage and outcome by Kaplan—Meier survival plots. RESULTS: Mean age at diagnosis was 48.6 years. Overall, 75% of tumours were detected in the course of planned examinations.  For women under age 50 at diagnosis, this figure was 68%.  Eighteen percent were mammographically negative, (23% in patients under age 50).  At first ("prevalence") round and at follow-up screening, 16% and 22% of tumours respectively were carcinoma in situ (CIS) while 27% and 22% respectively had evidence of nodal or distant spread (CaN+).  Comparison of screen-detected and other tumours showed that the latter were more frequently mammogram-negative and CaN+.  Overall five-year survival was 89% and five-year event-free survival 86%.  Five-year event-free survival was 100% for CIS, 88% for invasive cancer without nodal or distant spread and 67% for CaN+. CONCLUSIONS: The majority of cancers arising in women at increased genetic risk of breast cancer can be detected by planned screening, even in those under age 50.  Surveillance should include regular expert clinical examination and teaching of "breast awareness" as well as mammography.  Attention to the logistics of screening programmes may improve still further the proportion of tumours that are screen-detected.  The... [ABSTRACT FROM AUTHOR]

The major allergen of codfish (Allergen M) is a muscle protein belonging to the family of calcium binding parvalbumins. The primary structure of the molecule was established and the molecular weight was estimated from the sequence data to be 12,828. Allergen M consists of 113 amino add residues and one residue of glucose. A molecular arrangement of three domains (AS, CD and EF - the latter two bind one Ca2+ ion each) was described for Allergen M, analogous to carp parvalbumin pI 4.25. The suggested strucutre was based on the extensive intramolecular amino add homologies and the immunochemical cross-reactivities of the intact molecule and the two major isolated fragments. The immunological structure of Allergen M was studied by: 1. Modification of certain amino adds residues and study of the reactivity of the modified derivatives. 2. Examination of the immunochemical reactivity of a large number of overlapping peptides obtained by limited and selective tryptic hydrolyses. 3. Solid phase peptide synthesis (SPPS) of segments selected in regard to the reactivity of p re-examined native peptides. The immunological reactivity of the derivatives of Allergen M was assigned by: 1. Rocket line immunoelectrophoresis and quantitative precipitation using rabbit anti-Allergen M in precipitating antibody-mediated reactions and, 2. RAST/RAST-inhibition and PK test/PK-test inhibition using sere from individuals allergic to codfish in IgE-mediated reactions. The modification of Tyr-30 and Arg-75 in isolated and purified peptides indicated that the former was part of a reactive site whereas the latter did not contribute to the activity. Masking of Arg-residue or unchelating the two calcium ions from the native Allergen M, with the resulting perturbation of the tertiary structure, decreased the allergenicity by approximately 25%. Two major fragments of Allergen M were produced and purified; TM1 (residues 1-75) comprising domains AS and CD, and TMQ (residues 76-113) covering domain EF. Both were immunologically reactive; TM1 showing intermediate reactivity between Allergen M and TM2. A high degree of immunological cross reactivity was evident between TM1 and TM2. The finding was in concert with the high intramolecular amino add homologies of Allergen M, and suggested that the reactive sites were repetitively distributed along the polypeptide chain. The immunological reactivity of several long-sequence overlapping peptides obtained by limited and selective trypsin hydrolysis of Allergen M was studied. The immunologically reactive sites were accordingly assigned to the following regions of the chain: 1. Residues 33-44 on the junction between the AS and CD domains. 2. Residues 65-74 on the corresponding junction between the CD and EF domains. 3. Residues 88-96 on the calcium binding loop of the EF domain. These results were cross-examined by SPPS of these segments. A synthetic peptide with the sequence 49-64 of Allergen M, located in the calcium binding loop of the CD domain confirmed the immunological reactivity of this region. Peptide 49-64 incorporates two homologous tetrapeptides (Asp-Glu-Asp-Lys and Asp-Glu-Leu-Lys) interspaced by six amino acid residues. Changing the residues of the spacer arm had no influence on the reactivities. The conclusion was that the tetrapeptides attached at a distance of six amino-acids spacer-arm formed a binding locus for Ig-molecule. The same tetrapeptides are repeated in the sequence 51-64. A synthetic peptide of this sequence was also immunologically reactive. An octapeptide comprising one single tetrapeptide lacked the immuno-chemical reactivity. Similarly, solid phase synthesis of peptide 88-103 of the calcium binding loop of the EF-domain rendered an immunochemically reactive peptide. A high degree of homology between this peptide and the peptide 51-64 is evident although the former is devoid of the characteristic tetrapeptide. The synthesis of the N-terminal domain peptide 13-32 (AB-domain) was accomplished. The synthetic peptide was found to bind IgE antibodies from cod-allergic individuals' sera in direct PK-test. At identical concentration, a ratio of 1:6 for in vitro reactivity of the peptide relative to that of intact Allergen M was obtained. The peptide could also react with rabbit anti-Allergen M antibodies in rocket immunoelectrophoresis. The ability of the peptide to give positive direct PK-reaction and a rocket precipitate in immunoelectrophoresis preclude the achievement of a haptenic determinant. The synthetic peptides of Allergen M are currently utilized in trials on the regulation of IgE synthesis in experimental animals. [ABSTRACT FROM AUTHOR]

Purpose: Inherited ovarian cancer carries a serious prognosis. Prophylactic oophorectomy has been advocated. The degree to which inherited ovarian cancer is restricted to BRCA mutation carriers is not fully known. We wanted to determine the prevalence of BRCA mutation carriers in women at high risk from ovarian cancer., Experimental Design: Healthy women who were found to be at increased risk judged by family history were followed prospectively. Full BRCA1/2 mutation analysis was conducted on all patients who contracted pelvic cancer., Results: We identified 1,582 women at risk during 5,674 person-years. Forty infiltrating epithelial ovarian cancers, six peritoneal cancers, and one fallopian tube cancer were diagnosed. All but one of these patients (98%) had a BRCA mutation, a frequency that was significantly higher than for the 3 patients with borderline ovarian cancers, who were all mutation negative (P = 0.0002). Eighty-two percent of the detected mutations belonged to one of the 10 Norwegian founder mutations previously reported. At prophylactic bilateral salpingo-oophorectomy, cancer was found in 18 of 345 (5.2%) of mutation carriers compared with none in the 446 mutation negative (P = 0.0000)., Conclusions: In healthy women with a family history of ovarian cancer, high risk for ovarian cancer was restricted to BRCA1/2 mutation carriers. A woman at risk for ovarian cancer according to her family history should have access to full BRCA1/2 mutation testing before deciding on prophylactic bilateral salpingo-oophorectomy.

Norwegian health care for persons at risk for inherited colorectal cancer is regulated by national legislation on the use of predictive genetic testing and conforms with the international guidelines. This paper from the Norwegian Group on Inherited Cancer, is a consensus between all medical genetic institutions in Norway who handle hereditary colorectal cancer. The recommendations take locally available technology and health care resources into account and are realistic with regard to what can be done within the structure of the Norwegian health service. It gives an update of known genetic syndromes, including colorectal cancer, and indications for remitting patients to genetic examinations. The medical health care is detailed for each genetic group and includes prophylactic surgery and follow-up aimed at early diagnosis and treatment according to international standards. Genetic examinations include a thorough family history verified by medical files for all affected relatives, and comprehensive genetic testing for known syndromes in question. For hereditary colon cancer syndrome (HNPCC), the approach is to screen one tumour in a family member who is an obligate carrier with immunohistochemistry for lack of mismatch gene products, and --if found--proceed to full mutation analysis of the corresponding gene. The clinical geneticists are responsible for coordinating health services to those in need. They also have an obligation to collaborate to present the empirical results of the interventions made.

Norwegian health care for women at risk of inherited breast cancer conforms with the European consensus guidelines published in 1999 and the Norwegian legislation regulating the use of predictive genetic testing. This paper represents a consensus between all medical genetic institutions in Norway handling inherited breast cancer through the Norwegian Group on Inherited Cancer. It is an update based on new knowledge, the structure of our health service and locally available technology and health care resources. The indications for referring patients to genetic testing are maintained. The demonstration of local founder BRCA1 mutations has been used to develop a high capacity for testing for these mutations. Mutation carriers should be offered annual MRI of the breasts for early diagnosis. Oophorectomy at end of childbearing ages is advocated in BRCA mutation carriers and breast-ovarian kindreds. The clinical geneticists have the role of coordinating health service to those in need, and are required to collaborate to present the empirical results of the effects of the interventions.