Study Suggests Change in Radiation Guidelines in Older Women

An older woman who has radiation therapy after a lumpectomy may lower her need for a mastectomy later on, a new study says. Yet current guidelines recommend that older breast cancer patients not have radiation.

Researchers at the University of Texas MD Anderson Cancer Center in Houston reviewed the medical records of more than 7,400 women ages 70 to 79 who had had a lumpectomy for early stage, estrogen receptor-positive breast cancer between 1992 and 2002.

Almost 90 percent of these women 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, compared with only 3.2 percent of women who had received radiation.

It's not clear why these women needed a mastectomy, but the researchers say the most plausible reason is that the cancer came back.

Measurable difference

"Overall, in this group of women, radiation was associated with a decrease in mastectomy," says study senior author Benjamin Smith, M.D. "The absolute decrease was small, but it was certainly measurable."

The current guidelines are largely based on a 2004 study that concluded that radiation in older women only slightly decreased the odds of cancer recurring compared with receiving the estrogen-blocking drug tamoxifen alone. The risk that the cancer will recur is very low in older women.

Dr. Smith says that women with more aggressive tumors seemed to benefit more from radiation than other women.

Study limitations

The study, published in the journal Cancer, had some limitations. It wasn't designed to look at cause and effect, nor did it have information on which women took hormonal therapy, which can reduce the risk for a recurrence by about 50 percent.

But at the very least, the study should help doctors figure out which older patients would benefit most from radiation.

"I view this paper as adding a very nice layer of nuance on top of those guidelines," Dr. Smith says. "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."

Always talk with your health care provider to find out more information.