LB60
Long-term anastrozole versus tamoxifen treatment effects: LATTE Study
Jack Cuzick
Queen Mary, University of London, UK
Background
Breast cancer is increasingly becoming a survivable disease, and an
increasing number of recurrences occur late, so there is much interest in the
long-term efficacy and safety of treatments. Data exists on follow-up for
15-20 years after tamoxifen therapy but is lacking for the newer aromatase
inhibitors (AIs). The ATAC trial is the vanguard breast cancer trial for the use
of AIs in the adjuvant setting. AIs have been shown to significantly
improve survival in women with early breast cancer when compared to tamoxifen,
the previous standard for adjuvant therapy. Breast cancer recurrence
rates continue to be lower up to 4 years after cessation of treatment in the
anastrozole arm. This therefore poses a key question as
five-year survival with AIs is so good yet tamoxifen is known to have minimal
side effects.
Method
The ATAC trial will close at a median of 10 years of follow-up. The LATTE
study will continue to collect follow-up information for a further 5 years from
patients randomised to the monotherapy arms of the ATAC trial (approximately
4,500 patients worldwide). To compare the long-term treatment effects of
anastrozole versus tamoxifen, data will be collected in terms of efficacy
(local and distant recurrence, new contralateral tumours, new other primary
cancers, overall survival) and safety (major ischaemic cardiac and
cerebrovascular events, and serious fractures).
Aim
Results from this work will provide information for patients and clinicians
about the overall risks and benefits of AI therapy including long-term
consequences of treatment for women with early breast cancer, particularly when
making the choice between anastrozole and tamoxifen. Furthermore, as one
of the first studies of this type, both the feasibility of, and best methods
for, conducting long-term follow-up of cancer patients must be evaluated.
