Thursday, December 7, 2006
The LA Times reports on a recent UC Irvine study demonstrating that a sustained dose of RU-486 prevents breast cancer tumors in mice with BRCA1, a genetic predisposition for the disease. According to the Times,
The UCI team, which reported its findings in the journal Science, surgically implanted 14 of the mice that had the BRCA1 mutation with RU-486 pellets, which released the drug over a two-month period. All of the mice made it to their first birthday without developing any breast cancer tumors, according to the study.
Meanwhile, four mice implanted with a placebo pellet had all developed tumors by the time they were 5.2 months old. All of the 25 untreated control mice had tumors by the age of 8.7 months, the study found.
"It is a greater effect than I would have expected," said Eliot Rosen, a cancer researcher at Georgetown University who linked progesterone to BRCA1 but was not involved in the latest study. "It is a little surprising that it completely prevented the tumors."
Currently, the best way for women with a BRCA1 mutation to substantially reduce their risk is to surgically remove their breasts and ovaries before tumors have a chance to form.
Lee said RU-486 probably wouldn't be the best candidate for a human treatment because in addition to blocking progesterone, it binds with receptors involved in immunity and other important functions. For short-term use to end a pregnancy, that isn't likely to be a problem. But if patients are going to take a drug for years, it should target progesterone more precisely, she said.
Perhaps future research will help find the target progesterone amount . . . seems hopeful to me.