| 1. |
- Koul, Anjila, et al.
(författare)
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TP53 protein expression analysis by luminometric immunoassay in comparison with gene mutation status and prognostic factors in early stage endometrial cancer
- 2002
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Ingår i: International Journal of Gynecological Cancer. - : BMJ. - 1048-891X .- 1525-1438. ; 12:4, s. 362-371
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in the TP53 tumor suppressor gene have been shown to significantly correlate with poor prognosis in endometrial cancer. In the present study we have evaluated a luminometric immunoassay (LIA) for quantitative estimation of TP53 protein expression in 65 cytosol preparations from endometrial cancer, previously analyzed for mutations in TP53 exons 4-10. LIA showed high (greater than or equal to 0.6 ng/mg protein) expression of TP53 protein in all eight tumors with missense mutation, but high protein levels were also detected in 15 tumors with normal TP53 sequence. All four tumors with nonsense or frameshift mutations had low or no TP53 protein expression. LIA was further evaluated in a retrospective study of 201 cytosol samples from endometrial cancer. TP53 overexpression (>= 0.6 ng/mg protein) was observed in 22% of the tumors and correlated with nonendometrioid histology types (P = 0.005), poorly differentiated tumors (P = 0.001), higher FIGO grade (P = 0.001), DNA nondiploidy (P = 0.002), and high S-phase fraction (P = 0.03). After a median follow-up time of 6.8 years (range 0.7-9.9 years), 22 (13%) progressions were observed in the 175 patients with early stage (I-II) disease. TP53 overexpression (P = 0.04), FIGO grade 3 vs. 1 + 2 (P = 0.01), higher age (P = 0.02), and DNA nondiploidy (P < 0.001) showed significant correlation to shorter progression-free survival in these patients. We conclude that TP53 protein analysis by LIA provides an incomplete correlation to mutation status and cannot substitute for mutation analysis in assessment of prognosis in endometrial carcinoma. In comparison to TP53 overexpression and higher FIGO grades, DNA nonploidy status seems to be a better prognostic indicator to define a subset of early stage endometrial cancer patients who may benefit by adjuvant chemotherapy/radiotherapy.
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| 2. |
- Gentile, Massimiliano, et al.
(författare)
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Deletion mapping of chromosome segment 11q24-q25, exhibiting extensive allelic loss in early onset breast cancer
- 2001
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Ingår i: International Journal of Cancer. - 0020-7136 .- 1097-0215. ; 92:2, s. 208-213
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Tidskriftsartikel (refereegranskat)abstract
- Frequent allelic deletions at chromosome 11q24-q25 have been described in both early and late onset breast cancers, suggesting the existence of a gene locus implicated in the initiation and/or progression of the disease. In the present study we fine mapped this region further by loss of heterozygosity (LOH) analysis in a population of early onset breast cancer cases (n = 102, 22 to 36 years old). Loss of chromosomal material was assessed for possible association with patient survival as well as Nottingham histologic grade (NHG). Additionally, we investigated the involvement of the 11q24-q25 locus in a group of familial breast cancer cases with no detectable BRCA1 or BRCA2 gene alterations (n = 32, ages 28 to 40 years). Among the consecutive patients, extensive LOH was observed for all markers at 11q24-q25, with frequencies ranging from 42% to 54%. Deletion at the D11S4125 marker was found to be associated with reduced survival (p = 0.026), whereas the adjacent D11S387 marker correlated with higher histologic grade (p = 0.042). In the familial cases, the most telomeric markers showed substantially lower proportions of LOH, ranging from 10% to 21%. Comparison of the two patient groups demonstrated that this difference in LOH frequency was statistically significant for the D11S4098, D11S968, D11S387 and D11S4125 markers (p = 0.020, p = 0.029, p = 0.0070 and p = 0.0030, respectively). We conclude that 11q25 may harbor a gene implicated in early onset breast cancer. Our data suggest that the most probable position for this locus is defined by the markers D11S387 and D11S4125 and furthermore that it may play a less significant role in familial breast cancer cases not linked to either of the BRCA genes.
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| 3. |
- Loman, Niklas, et al.
(författare)
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Cancer incidence in relatives of a population-based set of cases of early-onset breast cancer with a known BRCA1 and BRCA2 mutation status
- 2003
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 5:6, s. 175-186
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Forskningsöversikt (refereegranskat)abstract
- Background Relatives of breast cancer cases have an increased risk of the disease. The risk increases with increasing numbers and decreasing age of onset of affected relatives. In families with a BRCA1 or a BRCA2 mutation, individual carrier status predicts the risk of breast cancer. In relatives of cases where both BRCA1 and BRCA2 mutations are excluded, the risk remains undetermined. Methods Standardized incidence ratios (SIRs) and cumulative cancer incidences were calculated for relatives of a population-based set of early-onset breast cancer index cases (younger than age 41 years) with a defined BRCA mutation status (n = 203). Results In first-degree relatives (FDRs) of mutation-negative cases, breast cancer incidences (SIR=2.3), prostate cancer incidences (SIR=1.7), cervix cancer incidences (SIR=3.3) and nonmelanoma skin cancer incidences (SIR=2.8) were increased. The risks of breast cancer, prostate cancer and nonmelanoma skin cancer were further increased in FDRs of breast cancer cases younger than 36 years of age. In high-risk individuals with at least one relative with breast cancer apart from the index case, but no BRCA mutation in the family, breast cancer incidence was increased (SIR=5.3); again the prostate cancer incidence was elevated (SIR=2.5). The cumulative incidence of breast cancer at ages 50 and 70 years for FDRs of index cases without a BRCA mutation was 3.6% and 12.8%, respectively. Similarly, the cumulative incidence of breast cancer for high-risk women was 6.3% and 21.1% at ages 50 and 70 years, and that for FDRs of BRCA mutation carriers was 17.2% and 27.7% at the same ages. Conclusion The incidence of breast cancer is increased for FDRs of women with early-onset breast cancer irrespective of the BRCA status in the family. Risk increases with decreasing age and with increasing number of affected relatives. The incidences of prostate cancer, cervix cancer and nonmelanoma skin cancer are elevated for FDRs of early-onset breast cancer cases without a BRCA mutation, indicating a possible association between these cancers and early-onset breast cancer.
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| 4. |
- Moller, P., et al.
(författare)
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Genetic epidemiology of BRCA1 mutations in Norway
- 2001
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Ingår i: European Journal of Cancer. - 1879-0852. ; 37:18, s. 2428-2434
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Tidskriftsartikel (refereegranskat)abstract
- Familial breast-ovarian cancer has been demonstrated to be frequent but unevenly distributed in Norway. This was assumed to be caused by the reduced population size created by the medieval Bubonic plague, 25 generations ago, and by the following rapid expansion. We have previously reported that four mutations account for 68% of the BRCA1 mutation carriers. Subsequent analysis has resulted in a total of 100 separate families carrying one of these founder mutations. The four mutations occurred on one specific BRCA1 haplotype each. The 1675delA, 816delGT and 3347detAG families originated from the South-West coast of Norway with a few Families in the north, while the traceable ancestors of the 1135insA families clustered along the historical inland road from the South-East to mid-Norway. The carriers of each of the four mutations today are descendants of one or a few individuals surviving the plagues. We may identify the majority of BRCA1 mutation carriers in Norway by screening for local founder mutations.
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| 5. |
- Möller, P, et al.
(författare)
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The BRCA1 syndrome and other inherited breast or breast-ovarian cancers in a Norwegian prospective series
- 2001
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Ingår i: European Journal of Cancer. - 1879-0852. ; 37:8, s. 1027-1032
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Tidskriftsartikel (refereegranskat)abstract
- Inherited breast cancer is a heterogenous group of diseases. We examined this heterogeneity in a prospective series of inherited breast and ovarian cancers, previously demonstrated to include 84% of inherited cancers. Ninety-two tumours (65 breast and 27 ovarian) in 82 patients from 70 kindreds were prospectively diagnosed. Fifteen of the breast cancers were in situ, 50 were infiltrating. 40 (49%) of the 82 women carried a BRCA1 mutation, whereas no mutation in BRCA2 was found. Approximately, two-thirds of the BRCA1 mutation carriers had one of the four most frequent Norwegian founder mutations. Ninety-five per cent of the epithelial ovarian cancers occurred in BRCA1 mutation carrying women versus 38% of infiltrating breast cancers and 7% of carcinoma in situ of the breast. The BRCA1 syndrome was phenotypically distinct with invasive, high grade, oestrogen receptor-negative breast cancers and epithelial ovarian cancers. Non-BRCA1/2 inherited breast cancers included carcinoma in situ and lobular carcinoma and were frequently bilateral. Non-BRCA1/2 inherited breast cancer is not associated with epithelial ovarian cancer and in breast cancers has distinct biological characteristics, indicating that the different subgroups of inherited breast cancer may need different healthcare services.
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| 6. |
- Thomassen, M, et al.
(författare)
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Loss of heterozygosity at BRCA2 in a ductal carcinoma in situ and three invasive breast carcinomas in a family with a germline BRCA2 mutation
- 2004
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 87:3, s. 273-276
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Tidskriftsartikel (refereegranskat)abstract
- We have examined a family with a germline BRCA2 mutation in three cases of invasive breast cancer and one case of ductal carcinoma in situ ( DCIS). Loss of heterozygosity (LOH) has been demonstrated at the BRCA2 locus in all cases. This result may suggest that the germline mutation in BRCA2 is the initiating step of DCIS and support the theory that DCIS is a precursor of invasive breast carcinoma in hereditary breast cancer.
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| 7. |
- Archey, WB, et al.
(författare)
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Increased CpG methylation of the estrogen receptor gene in BRCA1-linked estrogen receptor-negative breast cancers
- 2002
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 21:46, s. 7034-7041
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Tidskriftsartikel (refereegranskat)abstract
- A distinctive feature of BRCA1-linked breast cancers is that they typically do not express estrogen receptor-alpha (ERalpha). Previous investigation suggests that methylation of CpGs within the ERa promoter mediates repression of gene expression in some ERalpha-negative breast cancers. To determine if methylation of CpGs within the ERalpha promoter is associated with BRCA1-linked breast cancers, we evaluated methylation in exon 1 of the ERalpha gene in 40 ERalpha-negative breast cancers, 20 of which were non BRCA1-linked and 20 BRCA1-linked. CpG methylation was evaluated by either methylation-sensitive restriction digest (HpaII), methylation-sensitive PCR (MSP), or direct sequencing of bisulfite-treated genomic DNA. Results from HpaII digests and MSP documented a high degree of methylation, the MSP data showing slightly higher methylation in the BRCA1-linked group. CpGs analysed by direct sequencing showed an overall average methylation of 25% among non BRCA1-linked cancers and 40% among BRCA1-linked cancers (P=0.0031). The most notable difference was found at five particular CpGs, each of which exhibited a greater than twofold increase in methylation in the BRCA1-linked group compared to the non BRCA1-linked group (P < 0.03 for each CpG). Methylation of certain critical CpGs may represent an important factor in transcriptional repression of the ERa gene in BRCA1-linked breast cancers.
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| 8. |
- Borg, Åke
(författare)
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Molecular and pathological characterization of inherited breast cancer.
- 2001
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Ingår i: Seminars in Cancer Biology. - : Elsevier BV. - 1096-3650 .- 1044-579X. ; 11:5, s. 375-385
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Tidskriftsartikel (refereegranskat)abstract
- The two major breast cancer susceptibility genes, BRCA1 and BRCA2, account for the majority of familial breast–ovarian cancer, but only a modest proportion of breast cancer families without ovarian or male breast cancer. Search for additional breast cancer genes with traditional linkage analysis has so far been unsuccessful, probably due to genetic heterogeneity. Pooling of families of different ethnical, cultural, and geographical origin proved to be a useful approach when identifying BRCA1 and BRCA2, but for genes mutated only in specific populations it is important not to introduce locus heterogeneity by pooling. Genetic heterogeneity can possibly be circumvented by using objective means, such as tumour histopathology or gene expression profiling, for subclassification of families prior to linkage analysis. Also, additional breast cancer genes can be identified by further characterization of the function of BRCA1 and BRCA2 and their interacting proteins.
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| 9. |
- Johannsdottir, HK, et al.
(författare)
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Deletions on chromosome 4 in sporadic and BRCA mutated tumors and association with pathological variables
- 2004
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Ingår i: Anticancer research. - 1791-7530. ; 24:5A, s. 2681-2687
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chromosomal aberrations in breast tumors from BRCA1 and BRCA2 germ-line mutation carriers are considerably more frequent than what is seen in sporadic breast tumors. According to Comparative Genomic Hybridisation analysis (CGH), deletions on chromosome 4 are one of the most frequent events in BRCA1-associated tumors, suggesting inactivation of specific tumor suppressor genes. Materials and Methods: In the present study, 16 microsatellite markers covering chromosome 4 were used to map loss of heterozygosity (LOH) in tumors from BRCA1 (n =41) as well as in tumors from BRCA2 (n = 66) mutation carriers and in tumors from unselected cases of breast cancer (n = 68). Results: The frequency of LOH in these groups ranged from 16-73% in BRCA1-associated tumors, 13-42% in BRCA2-associated tumors and 8-33% in unselected tumors. LOH was significantly more frequent in BRCA1-associated tumors as compared to BRCA2-associated tumors and unselected tumors, and particularly high (over 70%) at 4q35.2. Pathological variables that were found significantly associated (pless than or equal to0.05) with LOH at specific markers were: high percentage of cells in S-phase, negative estrogen receptor status, young age at diagnosis and large tumors. Deletion mapping indicates the existence of seven non-overlapping regions at chromosome 4, which were identified in all three groups of tumors. Three of these seven regions, 4p16.3-p16.1, 4q27-q32.1 and 4q35.1-4qter, have not been reported in breast cancer previously. Conclusion: The results manifest the frequent alterations of chromosome 4 in BRCA1-associated breast tumors and indicate the location of several genes of potential importance in breast cancer development.
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| 10. |
- Loman, Niklas, et al.
(författare)
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Prognosis and clinical presentation of BRCA2-associated breast cancer
- 2000
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Ingår i: European Journal of Cancer. - 1879-0852. ; 36:11, s. 1365-1373
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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