Switching to anastrozole reduces recurrence of breast cancer
Switching postmenopausal women with breast cancer to the aromatase inhibitor anastrozole (Arimidex) after two years' treatment with tamoxifen more than halves the risk of recurrence compared with continuing tamoxifen, according to new research.
An Italian study randomised 448 women who had been on adjuvant tamoxifen
(20mg/day) for at least two years to continue tamoxifen or to switch
to anastrozole (1mg/day) for up to five years in total.
After a median follow-up of 36 months patients changed from tamoxifen
to anastrozole had experienced 17 events (12 disease recurrences, five
second primaries) compared with 45 events (32 disease recurrences, 10
second primaries) in those who continued with tamoxifen (P=0.0002).
Results also showed a trend to fewer deaths with anastrozole (4 vs 10
with tamoxifen, P=0.1).
Gynaecological changes were more common in patients who continued tamoxifen
(7.1 per cent vs 0.9 per cent, P=0.001). Gastrointestinal symptoms were
more common with anastrozole (6.3 per cent vs 1.3 per cent, P=0.006),
as was raised cholesterol (8.1 per cent vs 2.7 per cent, P=0.01).
Commenting on the clinical significance of the Italian study, Professor
Jeffrey Tobias, professor of cancer medicine at University College London
Medical School, said: “The results show that in women who have
been taking tamoxifen for two to three years but then have to stop due
to side effects or reduced efficacy, we can confidently consider treatment
with anastrozole as an alternative that is at least as effective and
better tolerated.”
The data were reported at the San Antonio breast cancer symposium held
in Texas earlier this month. |
