The study...raises new questions as to the comparative effectiveness of breast-conserving therapies such as lumpectomy...
Fremont, CA (PRWEB) January 28, 2013
A study released this week has found that patients with early stage breast cancer who were treated with lumpectomy plus radiation may have a better chance of survival than with those who underwent mastectomy.
The study—which appears in the Jan. 28, 2013 online version of the journal CANCER, and includes researchers from the Cancer Prevention Institute of California (CPIC), Duke Cancer Institute and UC San Francisco—raises new questions as to the comparative effectiveness of breast-conserving therapies such as lumpectomy, where only the tumor and surrounding tissue is surgically removed.
“Our findings showed that survival among patients treated with lumpectomy plus radiation had better survival than those treated with mastectomy for early stage breast cancer regardless of the hormone sensitivity of the tumor or the age of the patient,” said CPIC Research Scientist Scarlett Lin Gomez, Ph.D., one of the studies authors.
Basing their study on 14 years of data from the California Cancer Registry, a source of long-term outcome data for women diagnosed with and treated for breast cancer in California, the research team found that women age 50 and older at diagnosis with hormone-sensitive tumors saw the largest benefit of choosing lumpectomy plus radiation: they were 13 percent less likely to die from breast cancer, and 19 percent less likely to die from any cause compared with those undergoing mastectomy.
These results are particularly relevant in the context of the recent trend of more women, particularly younger women with very early cancers, opting for mastectomy over lumpectomy and radiation. These women may perceive mastectomy to be more effective at eliminating early stage cancer and therefore reducing the anxiety accompanying long-term surveillance.
The team analyzed data from 112,154 women diagnosed with stage I or stage II breast cancer between 1990 and 2004, including 61,771 who received lumpectomy and radiation and 50,383 who had mastectomy without radiation. The researchers looked at age, hormone status, and other demographic factors, along with tumor type and size to decipher whether each treatment had better outcomes for certain groups of women. Patients were followed on average for 9.2 years.
The researchers also sought to examine whether illnesses other than breast cancer, such as heart and respiratory disease, may have influenced whether women chose lumpectomy or mastectomy. Within three years of diagnosis, breast cancer patients who underwent lumpectomy and radiation had higher survival rates than those who chose mastectomy when all other illnesses were evaluated, a finding suggesting that women choosing lumpectomy may have been generally healthier.
However, the researchers also found that early stage breast cancer patients treated with breast conserving treatment had a significantly greater short-term survival rate from breast cancer than women who underwent lumpectomy with radiation.
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 Gomez, study authors include Daphne Y. Lichtensztajn and Christina Clarke, Ph.D., M.P.H., of the Cancer Prevention Institute of California; E. Shelley Hwang, M.D., MPH, chief of breast surgery at Duke Cancer Institute; and Barbara Fowble of the University of California San Francisco Helen Diller Family Comprehensive Cancer Center.
The study was supported by National Cancer Institute’s Surveillance, Epidemiology and End Results Program (HHSN261201000140C) awarded to the Cancer Prevention Institute of California. The collection of cancer incidence data used in this study was supported by the California Department of Health Services.
About the Cancer Prevention Institute of California
The Cancer Prevention Institute of California (CPIC) is the nation’s premier organization dedicated to preventing cancer and to reducing its burden where it cannot yet be prevented. CPIC tracks patterns of cancer throughout the entire population and identifies those at risk for developing cancer. Its research scientists are leaders in investigating the causes of cancer in large populations to advance the development of prevention-focused interventions. CPIC’s innovative cancer prevention research and education programs, together with the work of the Stanford Cancer Institute, deliver a comprehensive arsenal for defeating cancer. For more information, visit CPIC’s official website at http://www.cpic.org.