Novartis AG’s breast cancer pill Femara can significantly
reduce the risks that a woman’s cancer will return if it is used anywhere between
one year and seven years after finishing tamoxifen therapy.
U.S.
researchers said post-menopausal women who took Femara reduced the risk that
cancer would come back by 63 percent. Moreover, the risk of cancer spreading to
other areas of the body was reduced by 61 percent.
“What our results have shown for the first time in breast
cancer treatment history is that taking an anti-estrogen anywhere along that
line appears to have a dramatic reduction in the risk of recurrence,” said Dr.
Paul Goss of Massachusetts
General Hospital
and colleagues in the online issue of the Journal of Clinical Oncology.
The drug known generically as letrozole, belongs to a new
class of breast cancer drugs known as aromatase inhibitors, which block the
production of estrogen that can lead to cancer. It is recommended for use in
women past menopause.
Dr. Goss recommended women who had surgery and completed
adjuvant therapy years ago to consider starting on letrozole now.
“There are probably hundreds of thousands of breast cancer
patients around the world today who are in exactly this situation,” he said.
Dr. Goss underlined the fact that breast cancer could come
back after five-year therapy with tamoxifen.
“What is important for doctors and patients to recognize unfortunately is
that the risk of recurrence of this type of breast cancer does not end at five
years," Goss said in a telephone interview, according to Reuters.
Dr. Goss’s findings are based on an analysis of 1,579 women who decided to
switch to letrozole from a placebo after the trial was halted. Their results
were compared to about 800 women who stayed on the placebo. Those who began
letrozole had only a 2 percent risk of tumor recurrence almost three years
after the study ended compared with almost 5 percent in those choosing no treatment.
Dr. Goss’s findings were sustained by a second study conducted by Hyman Muss
of the University
of Vermont also published
yesterday in the Journal of Clinical Oncology. Muss found that letrozole was
effective in cutting the recurrence risk for women of all ages, including those
older than 70.
Dr’ Goss said his results would likely apply to all aromatase inhibitors: Pfizer
Inc’s exemestane, sold under the brand Aromasin and AstraZeneca Plc’s
anastrozole, sold under the brand Arimidex.
A study, involving 1,598 patients, found that exemestane reduced the risk of
recurrence by 56 percent if taken soon after completing tamoxifen treatment.
The studies were supported by the Canadian Cancer Society, the National Cancer
Institute of Canada, the US National Cancer Institute, and Novartis Pharmaceutical.
Women in the United
States have a 1 in 8-lifetime chance of
developing invasive breast cancer and a 1 in 35 chance of dying from breast
cancer. It is the second most common type of cancer after lung cancer and the
fifth most common cause of cancer death.
