Terwijl het lange termijn gebruik van Tamoxifen bij borstkanker patiënten normaal het risico’s op terugkeer van de minder agressieve vorm van borstkanker verkleint blijkt nu uit een nieuwe observatie studie van het Amerikaanse Fred Hutchinson Cancer Research Center dat de kans op de agressievere niet goed behandelbare vorm van borstkanker juist wordt verviervoudigd.
Comparing breast-cancer patients who received the estrogen-blocking drug tamoxifen to those who did not, the researchers found that while the drug was associated with a 60 percent reduction in estrogen receptor-positive, or ER positive, second breast cancer – the more common type, which is responsive to estrogen-blocking therapy – it also appeared to increase the risk of ER negative second cancer by 440 percent. “This is of concern, given the poorer prognosis of ER-negative tumors, which are also more difficult to treat,” said Li, an associate member of the Hutchinson Center’s Public Health Sciences Division.
http://www.fhcrc.org/about/ne/news/2009/08/25/tamoxifen.html
