Radiation of little benefit for breast cancer in aged

With lumpectomy, drugs, recurrence and survival rates similar, studies find

September 02, 2004|By Jonathan Bor | Jonathan Bor,SUN STAFF

After years of controversy over the best way to treat small breast tumors, researchers have found that thousands of older women can forgo radiation treatments without hurting their survival chances.

Two studies published today in the New England Journal of Medicine found that radiation provides no added benefit for women over 70 who receive lumpectomies and take the cancer-fighting drug tamoxifen.

"It suggests that upfront radiation is not necessary and may in fact be overtreatment for many of the older women," said Dr. Jerome Yates, vice president for research at the American Cancer Society. The society was not connected to the study.

Radiation treatments are much safer than they once were but cost many thousands of dollars and can produce unpleasant side effects including pain, swelling and skin discoloration.

Though the results might stir disagreement, researchers said the studies could spur a major shift in the standard of care for tens of thousands of breast-cancer patients each year. Almost 40 percent of the 200,000 women diagnosed each year are 70 or older, and most have relatively small breast tumors.

The findings are limited to lumpectomy patients whose tumors feed off the body's natural supply of estrogen - tamoxifen works by inhibiting the hormone - but that group represents the vast majority of women with the disease. A lumpectomy is the surgical removal of a tumor while leaving the breast largely intact.

Dr. Lauren Schnaper, a breast surgeon at Greater Baltimore Medical Center who participated in one study, said the findings might be profound for older women in rural areas who live far from radiation centers.

Such women are often forced to undergo mastectomies - total removal of the breast - because radiation was not a practical alternative. Now, many can feel reassured about skipping radiation or mastectomy.

"Picture an 80-year-old woman who had to have a mastectomy," said Schnaper, who treated many patients in the study while working at the University of Maryland Medical Center. "She may already be debilitated with other illness, maybe has arthritis and difficulty getting around."

The studies focused on different groups of women but reached conclusions that many viewed as complementary.

In a Canadian study, doctors assigned 769 lumpectomy patients to receive tamoxifen and radiation or tamoxifen alone. After five years, less than 1 percent of the patients who received radiation treatments had recurrences in the affected breast, compared with 7.7 percent who received the drug only.

Past age 60, however, the differences closed significantly - and past 70, they all but disappeared. And across all groups, there was no difference in the chance of surviving five years.

Dr. Anthony Fyles, a radiation oncologist at Toronto's Princess Margaret Hospital and lead investigator, said the study suggests to him that women between 50 and 60 should be encouraged to have radiation. Older women, especially those past 70, can safely pass it up.

"This has certainly changed our practice," said Fyles. "It's something we're offering to women as an option, with a full discussion of the risks and benefits of what's involved."

At the same time, Fyles said, the case could be made for women over 50 to skip radiation, so long as they understand that they might have a recurrence that could require another lumpectomy - and radiation. There remains no confusion about women with larger tumors, he said: Radiation is a necessary part of treatment.

In the second study, doctors focused on a more select group of patients - women 70 and older who had tumors no larger than a centimeter in diameter. (The Canadian researchers included women with tumors as large as 2 centimeters.)

At five years, there was a slight difference in the chance of recurrence in the affected breast - 1 percent for those who received radiation, 4 percent for those who did not. But there was no difference in the five-year survival rate: about 86 percent in both groups.

"If a patient does not need to have radiation therapy, her quality of life can improve significantly," said Dr. Kevin Hughes of the Massachusetts General Hospital in Boston. Hughes was the lead investigator of the study, which involved patients there and at several other cancer centers.

There could be several reasons why older women seem to do just as well without radiation treatments, which are designed to destroy any cancer cells that remain, Schnaper said.

Perhaps it is because tumors in older women grow more slowly and are less likely to spread, she said.

Even in rare cases when cancer returns to the breast, the odds are against a woman dying of breast cancer before she succumbs to other causes associated with aging.

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