New research, published in the journal Cancer on August 13th, indicates that older women (70-79 years) receiving radiation following a lumpectomy reduce their chances of needing a mastectomy in the future.
These research finding differ from current treatment guidelines that recommend older women with early, estrogen receptor-positive breast cancer that has not spread to the lymph nodes have a lumpectomy to remove the tumor, followed by hormonal therapy for five years (1x daily dose in pill form) but no radiation. These guidelines reflect that the risk of a recurrence is very low in older women compared to younger women. Radiation following a lumpectomy is standard practice for younger women.
Current guidelines are largely based on a 2004 study that found radiation for women in this age group only slightly decreased the odds of cancer recurring compared to receiving only the estrogen-blocking drug Tamoxifen (hormonal therapy).
In the new research study, the authors reviewed the medical records of more than 7,400 women aged 70 to 79 who had a lumpectomy for early-stage, estrogen receptor-positive breast cancer between 1992 and 2002. Almost 90 percent of these women had received radiation after surgery.
After a follow-up period of 10 years, 6.3 percent of women who did not get radiation needed a mastectomy versus only 3.2 percent of women who had received radiation.
“Overall in this group of women, radiation was associated with a decrease in mastectomy,” said study senior author Dr. Benjamin Smith, an Assistant Professor of radiation therapy at the University of Texas MD Anderson Cancer Center, in Houston. “The absolute decrease was small but it was certainly measurable.”
Certain women seemed to benefit more from radiation than others, namely those with high-grade (aggressive) tumors, Smith added.”These are highly aggressive-looking cell types,” said Dr. Philip Bonanno, Director of the Breast program at Northern Westchester Hospital in Mt. Kisco, N.Y. “This is a tumor that we know is going to be a bad actor given enough time.”
The study found that radiation was not necessarily helpful for patients 75 years and older who did not have high-grade tumors and whose cancer had not spread to the lymph nodes. Dr. Bonanno stated, “Women over 75 years of age are not all the same and neither are their cancers.”
Dr. Smith stated. “It’s unclear if the findings will be practice changing. At the very least, he said, the paper should help clarify which older patients would benefit the most from radiation. I view this paper as adding a very nice layer of nuance on top of those guidelines. In our practice group, we’ll be more enthusiastic about radiation in high-grade tumors and less enthusiastic in low-grade tumors, particularly in older women.”
SOURCES: Benjamin D. Smith, M.D., Assistant Professor, Radiation Therapy, University of Texas MD Anderson Cancer Center, Houston; Philip C. Bonanno, M.D., Director, Breast Program, Northern Westchester Hospital, Mt. Kisco, N.Y.