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- Bergman, Malin, 1967-
(författare)
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Genetic polymorphism and breast cancer risk in young women
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Breast cancer is the most common malignancy among women in the western world. Although the disease is rare in young women, it is one of the main causes of death at young age. The early onset breast cancer has demonstrated more aggressive pathological features than the late onset disease. These observations have raised the hypothesis that the biological background may differ between age categories.Breast carcinogenesis is a micro-evolutionary process that requires accumulation of DNA-damage and other epigenetic changes that promote cell survival and proliferation. The complexity of the disease makes it difficult to identify specific risk factors. Nevertheless, a large and compelling body of epidemiological and experimental data suggests that the cumulative dose of oestrogen is one key factor in the aetiology. Also, substantial data indicates that oxidative stress, from phosphorylation or other metabolic processes, is involved in the development of breast cancer. In young women, there is a strong genetic influence of breast cancer risk and beside mutations in highly penetrant genes, polymorphisms in a number of crucial genes may modify an individual's risk. Such modifier genes, associated with a more modest risk and high prevalence in the population, may contribute to a large proportion of the disease in the population. Identification of such predisposing polymorphisms may be an important step forward in identifiying individuals at risk. In the present thesis genetic polymorphisms in four different genes and their relation to early onset breast cancer, were analysed.In the first study, a polymorphism with a TaqI restriction site in the vitamin D3 receptor (VDR) gene was studied. VDR and its ligand, 1,25(OH)2D3, have been suggested to be important factors for differentiation of the breast epithelium and may suppress mammary tumorigenesis. The presence of a TaqI restriction site has been shown to correlate with increased transcriptional activity and mRNA stability of VDR, as well as high serum levels of 1,25(OH)2D3 and this high receptor activity may be protective against breast cancer. In the present study VDR TaqI polymorphism did not predict risk of early onset breast cancer. However, the results indicate an association between lymph node metastasis and genotype. In the second study, a promoter polymorphism in the CYP17 gene, which may influence the oestrogen synthesis, has been analysed. The polymorphism was correlated to the risk of early onset breast cancer, and the risk increased in a dose dependent manner. The fmdings indicated also a trend for risk allele carriers to have ER-negative and large tumours. Oestrogens are metabolized to potentially carcinogenic catecholoestrogens, which could be inactivated by and O-methylation, catalysed by Catechol-O-methyltransferase (COMT). This gene contains a variant which encode for a protein with decreased activity and is therefore predicted to be a risk allele. In the third study, the investigation of allele frequencies of the polymorphic COMT gene did not show any epidemiological evidences of implication in breast cancer. Finally; increasing numbers of studies indicate an important role for MnSOD in a number of cancer cell types. A genetic variant of MnSOD results in a less efficient transport into the mitochondria which may lead to an insufficient scavenging of free radicals. In this study, the mitochondrial targeting polymorphism was associated with risk of breast cancer in young women.In conclusion, genetic polymorphism in crucial genes may have impact on the risk of early onset breast cancer. Furthermore, some genotypes seems to influences the progression and outcome of the disease.
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| 2. |
- Dryver, ET, et al.
(författare)
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Follow-up of patients with Hodgkin's disease following curative treatment: the routine CT scan is of little value
- 2003
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 89:3, s. 482-486
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Tidskriftsartikel (refereegranskat)abstract
- A total of 10-40% of patients with Hodgkin's disease relapse following initial curative therapy. Intensive follow-up is resource intensive and may identify false relapses. We performed a retrospective review of all patients with Hodgkin's disease treated at our centre between 1990 and 1999 to evaluate the utility of the components of follow-up. A total of 107 patients met the inclusion and exclusion criteria. The median age was 33 years and the median duration of follow-up 38 months. The total number of follow-up visits was 1209 and total number of CT scans 283. There were 109 suspected relapses of which 22 proved to be true relapses. Of the latter, 14 were identified clinically, six radiologically and two via lab testing. The routine CT scan detected only two relapses (9%), yet accounted for 29% of the total follow-up costs. Based on data from our centre, the cost per true relapse was $6000 US, 49% incurred by radiological tests. The majority of the cost of follow-up was incurred by routine follow-up (84%) as opposed to the investigation of suspected relapses (16%). We conclude that most true relapses are clinically symptomatic and that the routine CT is an expensive and inefficient mode of routine follow-up.
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| 3. |
- Elit, L, et al.
(författare)
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Familial and hormonal risk factors for papillary serous uterine cancer
- 2002
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Ingår i: European Journal of Gynaecological Oncology. - 0392-2936. ; 23:3, s. 187-190
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To identify genetic and non-genetic risk factors for papillary serous uterine cancer. Methods: A case-control study was conducted. Case women with papillary serous uterine cancer were compared with two control groups: 1) women with endometrioid uterine cancer and 2) healthy women with no past history of cancer. Cases and controls were matched for age (within two years) and ethnic group. All study subjects completed a questionnaire addressing family history. The cases and healthy controls were assessed for factors associated with estrogen exposure. Results: The risks of breast cancer (RR 1.84, Cl 1.03-331) and of prostate cancer (RR 2.21, CI 0.77-6.37) were higher among the relatives of patients with papillary serous uterine cancer, than among relatives of those with endometrioid uterine cancer. Other significant risk factors included weight at 18 years (p = 0.04) and the use of estrogen replacement therapy (p = 0.04). Conclusion: Relatives of women with papillary serous cancer of the uterus had an increased risk of breast and prostate cancer. Hormonal exposure also increases the risk for this cancer. These Findings suggest that predisposing genetic factors, possibly related to hormone metabolism, may be common to the three forms of cancer.
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| 4. |
- Jernström, Helena, et al.
(författare)
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A prospective study of different types of hormone replacement therapy use and the risk of subsequent breast cancer: the women's health in the Lund area (WHILA) study (Sweden)
- 2003
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Ingår i: Cancer Causes and Control. - 1573-7225. ; 14:7, s. 673-680
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Reports suggest that combined estrogen plus progestin hormone replacement therapy (HRT) confers a higher breast cancer risk than estrogen alone. We aimed to establish whether breast cancer risk depends on the type of HRT formula. Methods: The cohort consisted of 6586 women, aged 50 - 64 years, from the Lund area, Sweden, with no reported breast cancer upon inclusion. We obtained information such as HRT use through a questionnaire between December 1995 and February 2000. New breast cancers were identified through the South Swedish tumor registry. Results: Between inclusion and December 2001, 101 women developed breast cancer. Only ever use of the continuous combined estrogen plus progestin ( CCEP) formula differed between cases and controls (45.2% versus 23.5%; p = 0.000001). Compared with never users, exclusive CCEP users had the highest age-adjusted hazard ratio HR 3.3 (95% CI: 1.9 - 5.6; p < 0.001), followed by users of CCEP in addition to other HRT formulas HR 2.8 (95% CI: 1.4 - 5.5; p = 0.003). No significant increase was seen in women who exclusively used other HRT formulas. Conclusion: Women who used CCEP had over three times the risk of developing breast cancer compared with never users and twice the risk compared with users of other types of HRT.
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| 6. |
- Jernström, Helena, et al.
(författare)
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Genetic and nongenetic factors associated with variation of plasma levels of insulin-like growth factor-I and insulin-like growth factor-binding protein-3 in healthy premenopausal women
- 2001
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Ingår i: Cancer Epidemiology Biomarkers & Prevention. - 1538-7755. ; 10:4, s. 377-384
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Tidskriftsartikel (refereegranskat)abstract
- Circulating levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein 3 (IGFBP-3) vary considerably between normal individuals. Recent epidemiological studies have provided evidence that these levels are predictive of risk of several common cancers. To evaluate possible sources of variation of the levels of circulating IGF-I and IGFBP-3 in females, we studied specific candidate genetic and nongenetic factors in 311 nulliparous, premenopausal Caucasian women, 17-35 years of age. Women who used oral contraceptives (OC) had reduced levels of IGF-I (269 versus 301 ng/ml; P = 0.001 adjusted for age) and increased levels of IGFBP-3 (4213 versus 4009 ng/ml; P = 0.002, adjusted for age) compared with nonusers. The ratio of IGF-I:IGFBP-3 was associated with the dose of estrogen contained in the OC (P(trend) = 0.006, adjusted for age). We identified a novel single bp polymorphism in the promoter region of the gene encoding IGFBP-3. This polymorphism was related to the level of IGFBP-3 in the circulation. Mean IGFBP-3 levels were 4390, 4130, and 3840 ng/ml for the AA, AC, and CC genotypes, respectively (P(trend) = 0.006, adjusted for age and OC use). We observed no effect of a recently described polymorphism in the promoter region of the gene encoding IGF-I on the plasma IGF-I level, but there was evidence for a modifying effect of this locus on the influence of OC on the IGF-I level. Our results support the view that circulating IGF-I levels and IGFBP-3 levels are complex traits and are influenced by a number of interacting genetic and nongenetic factors.
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| 7. |
- Jernström, Helena, et al.
(författare)
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Genetic factors related to racial variation in plasma levels of insulin-like growth factor-1: implications for premenopausal breast cancer risk
- 2001
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Ingår i: Molecular Genetics and Metabolism. - : Elsevier BV. - 1096-7192. ; 72:2, s. 144-154
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Tidskriftsartikel (refereegranskat)abstract
- The oral contraceptive pill is associated with a modest increase in the risk of early-onset breast cancer in the general population, but it is possible that the risk is higher in certain subgroups of women. The relative risk of breast cancer associated with oral contraceptive use has been reported to be higher for African-American women than for white women. African-American women also have a higher incidence of premenopausal breast cancer than white women. Circulating levels of insulin-like growth factor-1 (IGF-I) vary between ethnic groups and are positively associated with the risk of premenopausal breast cancer. In general, the plasma level of IGF-I is lower in women who take oral contraceptives than in women who do not. In an attempt to explain the observed ethnic difference in IGF-I levels with oral contraceptive use, we sought to identify polymorphic variants of genes that are associated with IGF-I levels and estrogen metabolism. We measured IGF-I and IGFBP-3 plasma levels in 503 nulligravid women between the ages of 17 and 35. All women filled out a questionnaire that included information about ethnic background and oral contraceptive use. Samples of DNA were used to genotype the women for known polymorphic variants in the IGF1, AIB1, and CYP3A4 genes. Black women had significantly higher mean IGF-I levels than white women (330 ng/ml versus 284 ng/ml; P = 0.001, adjusted for age and oral contraceptive use). IGF-I levels were significantly suppressed by oral contraceptives in white women (301 ng/ml versus 267 ng/ml; P = 0.0003), but not in black women. Among oral contraceptive users, the IGF-I level was positively associated with the absence of the IGF1 19-repeat allele (338 ng/ml versus 265 ng/ml; P = 0.00007), with the presence of the CYP3A4 variant allele (320 ng/ml versus 269 ng/ml; P = 0.01), and with the presence of the AIB1 26-repeat allele (291 ng/ml versus 271; P = 0.08). After adjusting for genotypes, ethnic group was no longer a significant predictor of the IGF-I level. IGF-I levels are higher among black than white women. Polymorphic variants in the CYP3A4, IGF1, and AIB1 genes are associated with increases in the plasma levels of IGF-I among oral contraceptive users and the variant alleles are much more common in black women than in white women. The high incidence of premenopausal breast cancer among black women may be mediated through genetic modifiers of circulating levels of IGF-I.
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| 10. |
- Lai, Joe, et al.
(författare)
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CYP gene polymorphisms and early menarche
- 2001
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Ingår i: Molecular Genetics and Metabolism. - : Elsevier BV. - 1096-7192. ; 74:4, s. 449-457
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Tidskriftsartikel (refereegranskat)abstract
- Early age at menarche is a risk factor for breast cancer. A previous study reported a significant positive association between the CYP3A4*1B variant allele and early puberty. We investigated whether polymorphisms of the CYP3A4, CYP17, CYP1B1, and CYP1A2 genes predict the age at onset of menarche. Five hundred eighty-three nulliparous women between ages 17 and 35, of various ethnic backgrounds, completed a questionnaire that included information about menstrual history. Samples of DNA were provided and used to genotype these women for polymorphic variants in the four genes. There was no significant difference in mean age at menarche between women who carried two variant CYP17 A2 alleles (12.5 years) and women who carried one or no variant allele (12.5 years) (P = 0.8, adjusted for ethnic group and year of birth). Similar results were found for the CYP1B1*3 variant allele and for the CYP1A2*1F variant allele. Women who carried two variant CYP3A4*1B alleles had an earlier mean age at menarche (12.0 years) than women who carried one or no variant allele (12.6 years) (P = 0.02). However, after adjusting for ethnic group and year of birth, no significant differences in mean age at menarche were found. The polymorphic variants of the CYP3A4, CYP17, CYP1B1, and CYP1A2 genes are unlikely to influence age of menarche.
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