Radiation’s Value in Breast Cancer Cited
Breast-conserving surgery involving only partial removal of breast tissue is replacing mastectomy in a growing number of breast cancer cases but many women are not receiving the additional radiation therapy that researchers say significantly reduces the chance of a recurrence, a new study has found.
The study, published today, found that the percentage of women receiving breast-conserving surgery for localized cancer rose from 6% in 1980 to 25% in 1985. But a quarter of the women under 65 and more than half of those 65 or older apparently received no radiotherapy.
This finding in the evolving field of breast cancer therapy may signify a gap between scientific knowledge and actual clinical practice, the researchers suggest. If so, women may be receiving “less then optimal” treatment under the new approach, researchers said.
“If these kinds of findings are repeated, then it is possible that these women who did not get the radiation therapy might have higher recurrence rates,” said Dr. Bruce A. Mann, an author of the study in the Journal of the American Medical Assn.
Traditionally, the favored treatment for breast cancer was mastectomy--removing the breast as well as perhaps lymph nodes in the armpit and the pectoral muscles. In recent years, new research, as well as early detection, have made possible a less-drastic approach.
That approach, called breast-conserving surgery, includes lumpectomy and several other procedures in which the surgeon removes the tumor and a surrounding margin of healthy tissue. The procedure is less disfiguring and makes it easier to reconstruct the breast.
In 1985, researchers backed by the National Cancer Institute announced that extensive, international trials have shown that breast-conserving surgery combined with a limited course of radiation therapy could be as effective as total removal of the breast.
“It was important because it gave a woman an option,” Dr. Arthur Holleb, chief medical officer of the American Cancer Society, said in a telephone interview Thursday. But he said, “Radiation is essential. That’s agreed upon.”
The aim of Mann’s study was to determine whether the recent advances in scientific understanding of breast cancer had trickled down into everyday practice. His group at the University of New Mexico School of Medicine examined 6,030 cases recorded by the New Mexico Tumor Registry between 1969 and 1985.
They found few changes in practice before 1980--despite data supporting breast-conserving surgery published during the 1960s and 1970s. But between 1980 and 1985, with increased public demand for and testing of the approach, changes became widespread.
For example, most surgeons operating on breast cancer in New Mexico had not performed a breast-conserving operation before 1981, the group found. But over the next five years, most used the procedure at least once.
“There has been a marked shift in New Mexico in the surgical approach to local-stage breast cancer in the 1980s,” the study said. “This shift involved most surgeons treating the disease and included women of all age groups.”
The researchers said in interviews that they could only speculate on why they found no documentation of radiotherapy in many of those cases, even though they examined registry records, patient files and records of radiotherapy facilities.
Requires Daily Therapy
Some patients may have been offered radiation and refused it, perhaps unable or unwilling to pay the cost or devote the time, the researchers said. The treatment usually requires daily visits to a radiation therapist for five to six weeks after surgery.
“I suppose in some cases the doctor may say, ‘Well, the lesion is small, the surgical margins are clear and maybe we don’t need any more,’ ” said Dr. Charles Key, who worked on the study with Mann.
It is too early to tell whether the lack of radiation therapy will affect the rate of cancer recurrence and survival in the women studied. Key said his group intends to track the survival rates of the women.
The study sponsored by the National Cancer Institute in 1985 predicted a significantly higher cancer recurrence rate among women who received no radiation. Projecting from preliminary findings, the researchers predicted that 8% of the women who had received radiation would experience a recurrence within five years, compared to 28% of the women who underwent no radiotherapy.
