title: Risk factors and risk reduction of breast and ovarian cancer.
abstract: OBJECTIVE
  Breast and ovarian cancer remain a significant burden for women living in the Western world. This paper reviews the risk factors and current strategies to prevent these diseases.
  
  
  RESULTS
  Established factors associated with the risk of breast cancer include family history, reproductive factors and lactation, as well as age at menarche and menopause. Hormone replacement therapy increases the risk, whereas oral contraceptives probably confer no increased risk. Alcohol moderately increases the risk, whereas a diet rich in folate and carotenoids might be protective. The role of other dietary factors, smoking and physical exercise remain unclear. Important risk factors for ovarian cancer are reproductive factors and possibly the long-term use of hormone replacement therapy. The risk is decreased by oral contraceptives. In carriers of a BRCA1 or BRCA2 gene mutation, prophylactic surgery can significantly reduce the risk of breast as well as ovarian cancer. Tamoxifen may be considered as a chemopreventive agent in women with a high risk of breast cancer, including carriers of a BRCA2 mutation, but is probably not effective in BRCA1 carriers.
  
  
  CONCLUSIONS
  During the period of this review, the importance of several known risk factors was confirmed, whereas the effects of other factors became more clear. Chemoprevention and prophylactic surgery have emerged as preventative options that can reduce the risk of breast and ovarian cancer.
authors.affiliation: Department of Medical Oncology, Erasmus MC - Daniel den Hood, Rotterdam, The Netherlands. brekelmans@onch.azr.nl
authors.forename: Cecile T M
authors.initials: CT
authors.lastname: Brekelmans
mesh_terms: D000437:Alcoholism / Q000150:complications; D001943:Breast Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D003276:Contraceptives, Oral / Q000009:adverse effects; D004032:Diet; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008019:Life Style; D010051:Ovarian Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D011322:Primary Prevention / Q000379:methods*; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012907:Smoking / Q000009:adverse effects
chemical_list: D003276:Contraceptives, Oral