Breast Cancer

, Volume 15, Issue 1, pp 10–16

Chemoprevention of breast cancer

Conference Paper Invited Lecture


Trials with tamoxifen have clearly shown that the risk of developing oestrogen receptor positive breast cancer can be reduced at a late stage in the natural history with prophylactic agents. About half of the oestrogen receptor positive cases were prevented, but there was no beneficial effect on ER-negative cancers. The current challenge is to find new agents which achieve this or better efficacy but with fewer side effects. Recent results indicate that the SERM raloxifene has similar efficacy to tamoxifen, but leads to fewer endometrial cancers, gynaecologic symptoms, and thromboembolic events. Results for contralateral tumours in adjuvant trials suggest that aromatase inhibitors may be able to prevent up to 70–80% of ER-positive breast cancers, and this is currently being investigated in two large prevention trials, one using anastrozole (IBIS-II) and the other exemestane (MAP.3). New agents are needed, for receptor negative breast cancer and several possibilities are currently under investigation.


Breast cancer Prevention Tamoxifen Raloxifene SERMs Aromatase inhibitors 

Copyright information

© The Japanese Breast Cancer Society 2007

Authors and Affiliations

  1. 1.John Snow Professor of Epidemiology, Cancer Research UK Centre for Epidemiology, Mathematics and Statistics, Wolfson Institute of Preventive Medicine, Queen Mary’s School of Medicine and DentistryUniversity of LondonLondonUK

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