Results from the largest-ever observational study of women with early breast cancer suggests that early stage breast cancer survival may be better with lumpectomy plus local radiation than with mastectomy. The news is timely because over the last 10 years, there has been a growing tendency for women diagnosed with breast cancer to opt for mastectomy, even if they have small early cancers.
Overall survival was 19 percent higher after the less invasive breast-conserving treatment, which is a combination of lumpectomy and radiation, than with mastectomy after adjustment for other factors, E. Shelley Hwang, MD, MPH, of Duke University Medical Center, and colleagues reported online in Cancer.
Researchers examined data on over 112,000 cases of stage I and stage II breast cancer in California. These cases, diagnosed between 1990 and 2004, each resulted in either mastectomy or lumpectomy plus radiation therapy. The women were then followed until 2009, and the researchers compared the results of the different types of treatment.
The scientists found that in the first three years following surgery, women who had mastectomies were more likely to die from heart disease and other diseases compared with women who had lumpectomies. Overall, they found that women who had lumpectomy plus radiation were slightly more likely to survive cancer than women who had mastectomy.
The biggest effect was seen in women over 50 with hormone-sensitive (hormone-receptor positive) breast cancers. Their risk of dying from breast cancer during the follow-up was 14 percent lower than similar women with similar cancers who had a mastectomy. Furthermore, the same was true across all ages and cancer types.
It isn t clear to me why in the past 10 years or so there has been a growing tendency for women diagnosed with breast cancer to opt for mastectomy as opposed to lumpectomy, says ACSH s Dr. Gilbert Ross, but this study suggests that lumpectomy with local radiation is superior in terms of cancer outcome, albeit not by a huge amount, than mastectomy. Of course, given its observational nature, a cause-and-effect relationship cannot be asserted.