Millions of women facing an elevated risk for breast cancer could slash their chances of getting the widely feared malignancy by taking a hormone-blocking pill used to treat the disease or prevent a recurrence, researchers say.
A compound known as an aromatase inhibitor cuts the breast cancer risk by 65 per cent for women prone to the disease for any reason, such as having risky genes, a relative who had the disease or being older than age 60, a long-awaited international study of more than 4500 women has concluded.
The results mark a highly anticipated advance towards the elusive goal of offering women the first safe way to protect themselves from a leading cancer killer. Women have long been able to take an older class of anti-estrogen drugs to reduce their risk, but few do because of possible side effects, including uterine cancer and life-threatening blood clots. Many experts had hoped aromatase inhibitors would offer a safer, more acceptable alternative. The new study was the first time one had been tested.
''This is a major step forward,'' Larry Norton, a breast cancer expert at Memorial Sloan-Kettering Cancer Centre in New York who was not involved in the research. ''This is a long-awaited report from [among] the most highly-respected investigators in the field concerning a critically important topic in cancer prevention.''
Some breast cancer patient advocates and other experts, however, remained cautious. A 65 per cent reduction in risk is significant, but the absolute risk for these women remains small. Although aromatase inhibitors do not appear to cause uterine cancer or blood clots, the long-term safety of medicating women for many years remains far from clear, some experts say.
''This intervention offers women perhaps a more palatable option,'' said Andrew Seidman, a breast cancer expert speaking on behalf of the American Society for Clinical Oncology. The findings were posted online by The New England Journal of Medicine, which also offered a strongly worded editorial endorsing the results. ''It's a significant development,'' Dr Seidman said.
In the study, 4560 women in the US, Canada, Spain and France daily took 25 milligrams of Aromasin, which is known generically as exemestane, or a placebo. All the women were considered in danger of getting breast cancer because they were at least 60, had a close relative who had the disease, or scored high on a commonly used risk assessment scale.
The study was partially funded by Pfizer, which makes exemestane, but conducted independently by the Canadian Cancer Society's NCIC Clinical Trials Group.
Source: The Washington Post.
