A new U.S. study examining survival rates for women with early stage breast cancer found that surgery such as lumpectomy that preserves the rest of the breast may offer survival odds as good as, or even better than, mastectomies.
Despite clinical trials showing lumpectomy, or removal of the cancer only, to be as effective as mastectomies in treating early breast cancers, the number of women choosing breast removal has been on the rise, wrote lead researcher E. Shelley Hwang in the journal Cancer.
"It was kind of an exciting and hopeful message that women don't have to go off to get a mastectomy to do better," said Hwang, from the Duke Cancer Institute in Durham, North Carolina.
"I think a lot of women were making that decision (for mastectomy) because they thought the lumpectomy was not enough. In that context, we wanted to know if lumpectomy works just as well as mastectomy in the modern era."
For the study, they used data collected by the Cancer Prevention Institute of California on 112,154 women who were diagnosed with stage I or II breast cancer between 1990 and 2004.
The majority - 55 percent - had a lumpectomy with radiation, and the rest had a mastectomy without radiation. The researchers then tracked the women's health for an average of nine years.
Overall, 31,425 women died by the time the study ended in 2009, and 39 percent of those deaths were due to breast cancer.
But the researchers found that the women who had a lumpectomy with radiation were more likely to survive than women who had a mastectomy, regardless of age or cancer subtype.
The difference was most pronounced among women who were over 30 years old and diagnosed with the most common type of breast cancer, one that's fed by hormones like estrogen or progesterone. Those who chose lumpectomy had a 19 percent lower chance of dying from breast cancer than counterparts who got mastectomies.
The survival advantage with lumpectomy held up even when researchers accounted for age, tumor stage and type, race, economic status and other factors. Among women younger than 50 with hormone-sensitive cancers, for instance, those who had lumpectomy had a 7 percent lower chance of death than those who had mastectomy.
Hwang said the survival difference might be partly explained by the fact that women who got a mastectomy tended to be in worse health to begin with.
The study cannot prove that lumpectomy alone is the factor responsible for the improved survival, and researchers did not have access to some specific details about the women's tumors, or whether some had genetic susceptibility to breast cancer.
"I wouldn't overstate these results, because survival can come from other things," said Dawn Hershman, co-leader of the Breast Cancer Program at the Columbia University Medical Center in New York - though she did say the results are reassuring.
"Sometimes patients in practice can be very different than patients in randomized trials," she added. "It's reassuring that patients who get breast-conserving therapy do at least as well as those with mastectomy."