IBIS II: a breast cancer prevention trial in postmenopausal women using the
aromatase inhibitor anastrozole.
Author(s): Cuzick J.
Affiliation(s): Cancer Research UK Centre for Epidemiology, Mathematics and Statistics, Wolfson
Institute of Preventive Medicine, Queen Mary, University of London, Charterhouse
Square, London, EC1M 6BQ, UK. jack.cuzick@cancer.org.uk
Publication date & source: 2008, Expert Rev Anticancer Ther. , 8(9):1377-85
Tamoxifen has been shown to reduce the incidence of estrogen receptor-positive
breast cancer by approximately 50% in high-risk women. Similar results are seen
for raloxifene, but it has a more favorable side-effect profile. Data on
contralateral tumors from women in adjuvant trials treated with aromatase
inhibitors suggest that new tumors can be reduced by another 50% with these
drugs, suggesting a potential 75% reduction of estrogen receptor-positive tumors
when used in a prophylactic manner. Side effects appear to be fewer with the
aromatase inhibitors, with no excess of gynecologic (including endometrial
cancer) or thromboembolic events, but an increase in fracture risk and joint
symptoms does occur. IBIS II is a placebo-controlled prevention trial evaluating
5 years of the aromatase inhibitor anastrozole in high-risk postmenopausal women.
The primary end point is breast cancer incidence, but major efforts are also
being directed at minimizing any fracture risk.
|