"Our findings are observational but do suggest the possibility that women who were treated with less invasive surgery had improved survival compared to those treated with mastectomy for stage I or stage II breast cancer," said E. Shelley Hwang, M.D., MPH, chief of breast surgery at Duke Cancer Institute and the study's lead author.
"Given the recent interest in mastectomy to treat early stage breast cancers despite the research supporting lumpectomy, our study sought to understand what was happening in the real world, how women receiving breast-conserving treatments were faring in the general population," Hwang
colleagues were surprised to also find that early stage breast cancer patients treated with breast-conserving treatment had a significantly better short-term survival rate from breast cancer than women who underwent mastectomy.
A subset analysis limited to women with stage I cancer only showed consistent results.
"The hopeful message is that lumpectomy plus radiation was an effective alternative to mastectomy for early stage disease, regardless of age or tumor type," said Hwang
"Our study supports that even patients we thought might benefit less from localized treatment, like younger patients with hormone-resistant disease, can remain confident in lumpectomy as an equivalent and possibly better treatment option."
The authors emphasize that observational studies such as this one cannot establish causality between type of surgery and outcome and that longer follow up is needed. Nevertheless, this is a provocative observation that requires more research to understand whether patient factors that were not available for analysis might contribute to these observed survival differences.
In addition to Hwang, study authors include Daphne Y. Lichtensztajn, Scarlett Lin Gomez, and Christina A. Clarke of the Cancer Prevention Institute of California.