Authors' objectives:

This systematic review was conducted to estimate the level of increased breast cancer among women with defined risk factors as requested by the National Screening Unit (NSU), Ministry of Health. These risk factors included: previous breast cancer, at-risk lesions such as atypical ductal hyperplasia, lobular carcinoma in situ, lobular hyperplasia and sclerosing adenosis, increased breast density, childlessness, early menarche, postmenopausal obesity, exogenous hormone use, dietary factors and alcohol. The NSU specifically did not wish the scope to include genetic predisposition (especially BRCA1 and BRCA2) or family history in the scope of the review.

Authors' recommendations: The following conclusions are based on the current evidence available from this report's critical appraisal of literature published on risk factors for breast cancer in women. Factors with a higher level of risk (RR>2.0) included: past history of breast cancer selected precursor lesions of breast cancer, including atypical ductal carcinoma, lobular carcinoma and ductal carcinoma in situ increased breast density Other factors appeared to have a moderate level of increased risk (RR 1.5-2.0): heavy alcohol intake Some risk factors appeared to have modest levels of increased risk (RR 1.0-1.5): nulliparity post menopausal obesity hormone replacement therapy current use of oral contraceptives or recent use of oral contraceptives high total energy intake Finally, for some risk factors the level of increased risk was difficult to determine: early menarche (likely to be relatively modest) xenoestrogens phytoestrogens stilboestrol

Authors' methods: Systematic Review

Project Status: Completed

URL for project: http://nzhta.chmeds.ac.nz/publications.htm

Year Published: 2007

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: New Zealand

Organisation Name: New Zealand Health Technology Assessment

Contact Address: Department of Public Health and General Practice, Christchurch School of Medicine and Health Sciences, University of Otago, P.O. Box 4345, Christchurch, New Zealand. Tel: +64 3 364 1145; Fax: +64 3 364 1152;

Contact Name: nzhta@chmeds.ac.nz

Contact Email: nzhta@chmeds.ac.nz

Copyright: New Zealand Health Technology Assessment (NZHTA)