breast cancer
Three weeks of radiation treatment work just as well as the usual course of five weeks or more for women with early-stage breast cancers, Canadian researchers have reported, after monitoring a large group of patients for 12 years.
METHODS Less radiation may reach the heart and lungs if a patient is on a special mattress on her stomach, right, instead of her back.
The results, presented Monday at a conference in Boston, provide some of the strongest evidence yet that radiation schedules can safely be shortened to make life easier for patients and to let clinics reduce their waiting lists and treat more women without buying more machines.
Experts say the new findings, from a respected study, could change the standard of care in the United States. The typical schedule now involves five to seven weeks of daily treatments, and most women would welcome a chance to get it over with faster — especially those who work, have small children or live far from the clinic.
About 180,000 women a year develop breast cancer in the United States, and most need radiation. From 30 percent to 40 percent may be candidates for the type of treatment given in the study.
Some centers in this country already offer shorter courses of treatment, but they are more widely available in Canada and parts of Europe.
“We’ve really got to give it serious consideration in the United States,” said Dr. Anthony L. Zietman, a radiation oncologist at Harvard Medical School and the Massachusetts General Hospital Cancer Center, and president-elect of the American Society for Therapeutic Radiology and Oncology. He was not involved in the Canadian study.
But Dr. Zietman cautioned that the results applied only to women with early cancers like those in the study, which were removed by lumpectomy and had not spread to the lymph nodes. Often, women with such early cancers do not need chemotherapy.
Other major changes in radiation are also in the works. Doctors are experimenting with ways to treat just part of the breast rather than all of it, and to make the treatment safer, they are trying to avoid exposing the heart and lungs to radiation.
The purpose of radiation is to keep cancer from coming back in the same breast where it first occurred, by killing any tumor cells that may have evaded surgery and chemotherapy. Cancer cells are more vulnerable to radiation than are normal ones, and the treatment has always been a balancing act between giving enough radiation to destroy the tumor cells but not enough to cause serious damage to healthy tissue and organs.
The changes now being made result in part from the overall success in treating early breast cancers, Dr. Zietman said. Survival rates have climbed so high — 98 percent of women with early-stage cancers survive at least five years — that it is now considered reasonable to step back, look at women’s quality of life and try modifying the regimens to make treatment less onerous.
“It’s a bit of a change in our thinking,” Dr. Zietman said.
Researchers also hope that faster treatment will help make radiation available to more women. Currently, about 20 to 30 percent of women in North American who need it skip it. And some women who could have lumpectomy plus radiation choose mastectomy instead, simply to avoid radiation, because they live too far from a clinic to travel back and forth for all the treatments.
Not all medical centers offer the newer techniques, and they are not right for every woman. But for many women, there are choices now where none existed before — though it may take some effort to find out about them.
“Patients have to speak up,” Dr. Zietman said.
If the standard regimen is recommended, he said, a woman should ask: “Does it have to be that way? Am I one of the people who could be treated with partial breast irradiation, or, if I need the whole breast treated, could it be done in some more abbreviated fashion?”
He added, “Maybe they can, maybe they can’t.”
Some radiation oncologists may resist change, fearful of giving up the tried and true formulas they were taught, Dr. Zietman said. He noted that the standard treatment had 30 years of evidence to back it up, whereas the newer approach had less than half that. But still, the field is moving ahead.
“You don’t give all women with breast cancer the same treatment,” he said. “You base it on what they have, and who they are.”
Canadian researchers decided to study the shorter courses because doctors there and in England had begun using them without a formal trial, to make the most of a limited number of radiation machines.
The study included 1,234 women who started treatment at one of eight hospitals from 1993 to 1996. Half of the women received the standard regimen of 25 treatments in 35 days (five treatments a week for five weeks). The other half had 16 treatments in 22 days. The shorter course used slightly higher daily doses of radiation, but the total cumulative dose was slightly lower.
There were concerns that the lower overall dose would allow recurrences, or that over time the higher daily doses might damage the breast tissue, heart or lungs. Radiation injuries can take years or even a decade or more to show
I am P.h.D Student in Azerbaijan National Academy of Sciences.. My Search Subject the rule of ESR1 and ESR2 gene Mutations in Breast Tumorogeneis