Washington – Chemotherapy and hormone treatment have dramatically reduced the death rate from early breast cancer, according to a major international analysis that indicates the often- arduous regimens do cure many women.
The latest data from a massive, ongoing project involving 145,000 women with early breast cancer found that chemotherapy and hormone treatment continue to protect many women from dying from the disease for at least 15 years.
The protection often gets stronger over time, increasing the likelihood that the therapy is truly eradicating cancer from the patients’ bodies.
The findings provide the most convincing support yet for using aggressive strategies against the most common malignancy to strike women, and they help explain why the death rate from breast cancer has been dropping in many countries, including the United States and Britain, experts said.
Because breast cancer therapies have evolved since the studies in the analysis were conducted, survival rates may be even better now, the researchers said.
But they noted that much more work is still needed to prevent breast cancer, to develop treatments tailored to women’s cancers, and to find better ways to predict an individual’s prognosis.
“While these numbers clearly translate into more women living longer, which is good news, it doesn’t translate into an individual prediction,” said Barbara Brenner of Breast Cancer Action, a patient advocacy group.
“People always want to know, ‘What is going to happen to me?’ This study can’t answer that.”
“This is really good news,” said Sarah Darby of the University of Oxford in England, who led the analysis being reported in the Saturday issue of the journal The Lancet. “It means that the standard therapies we’re giving women really are working. It’s really quite exciting.”
The analysis showed, for example, that a middle-aged woman with a diagnosis of early- stage breast cancer cuts her risk of dying by about half by undergoing six months of chemotherapy and taking hormone treatment for five years, if she is medically eligible for both.
Every year, about 211,240 women have breast cancer diagnosed in the U.S. and about 40,410 die from the disease, making it the most common cancer among women and the second leading cancer killer, after lung cancer.
For most women, it is now standard practice to treat early breast cancer with surgery and radiation, followed by chemotherapy to reduce the risk of a recurrence by wiping out cancer cells lurking elsewhere in the body.
If their tumors are sensitive to the hormone estrogen, many women also take the estrogen-blocking drug tamoxifen for about five years to further reduce the risk of recurrence. (A new generation of hormone therapy has begun to replace tamoxifen.)
While earlier studies have shown that the approach reduced the chances of a relapse and increased the odds of survival, there have been haunting concerns about how long those benefits last inasmuch as breast cancer has a knack for hiding in the body for years or even decades before re-emerging.
The new findings should alleviate lingering doubts, reassuring women who went through the sometimes-grueling regimens that they were worthwhile, and encouraging women who are not receiving such treatment to do so, Darby and others said.
“There are a lot of women out there who are not getting these treatments and could benefit from them,” Darby said. “They are not a magic bullet, but as these data show, they clearly do offer substantial benefit.”
