Journal Article

Cytochrome P450 1B1 gene polymorphisms and postmenopausal breast cancer risk

Tove Rylander-Rudqvist, Sara Wedrén, Fredrik Granath, Keith Humphreys, Susanne Ahlberg, Elisabete Weiderpass, Mikael Oscarson, Magnus Ingelman-Sundberg and Ingemar Persson

in Carcinogenesis

Volume 24, issue 9, pages 1533-1539
Published in print September 2003 | ISSN: 0143-3334
Published online September 2003 | e-ISSN: 1460-2180 | DOI:
Cytochrome P450 1B1 gene polymorphisms and postmenopausal breast cancer risk

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics


Show Summary Details


Cytochrome P450 1B1 (CYP1B1) is active in the metabolism of estrogens to reactive catechols and of different procarcinogens. Several studies have investigated the relationship between genetic polymorphisms of CYP1B1 and breast cancer risk, however, with inconsistent results. We investigated such an association in postmenopausal Swedish women, with special emphasis on long-term menopausal hormone users, in a large population-based case-control study. We genotyped 1521 cases and 1498 controls for the CYP1B1 single nucleotide polymorphisms (SNPs) m2, m3 and m4 and reconstructed haplotypes. The frequencies of CYP1B1*1, CYP1B1*2, CYP1B1*3 and CYP1B1*4 alleles among controls were estimated to be 0.087, 0.293, 0.444 and 0.175, respectively. It thus appeared that very few haplotypes contained combinations of SNPs at two or three loci and that single SNP genotype data effectively represented haplotypes. Odds ratios (OR) and 95% confidence intervals (CI) were calculated from logistic regression models. We found no overall association between any CYP1B1 genotype and breast cancer risk. The data indicated, however, that women who had used meno- pausal hormones for 4 years or longer, and carried the CYP1B1*3/*3 genotype may be at increased risk of breast cancer, OR 2.0 (95% CI 1.1–3.5), compared with long-term users without this genotype. We explored the effect of CYP1B1 genotype on breast cancer risk in subgroups defined by body mass index, family history, smoking and catechol-O-methyl transferase genotype, but found no convincing evidence for interaction. In summary, our results strongly indicate that the studied CYP1B1 gene polymorphisms do not influence breast cancer risk overall but may modify the risk after long-term menopausal hormone use.

Keywords: BMI, body mass index; CI, confidence interval; COMT, catechol-O-methyl transferase; CYP1B1, cytochrome P450 1B1; DASH, dynamic allele-specific hybridization; OR, odds ratio; SNP, single nucleotide polymorphisms

Journal Article.  5102 words. 

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.