Radiation after surgery for early-stage breast cancer improves survival chances for most patients, according to a study that analyzed the case histories of more than 9,000 women.
Two doctors evaluated the results of 15 international studies and found that women who omitted radiation therapy after surgery were dying at a rate 8.6 percent higher than women who had the radiation.
A decision against radiation "may translate into a considerable survival disadvantage for patients,'' wrote Dr. Vincent Vinh-Hung of the Academic Hospital in Jette, Belgium, and Dr. Claire Verschraegen of the University of New Mexico Cancer Research and Treatment Center in Albuquerque.
A report on the analysis appears this week in the Journal of the National Cancer Institute.
Radiation is given to most early-stage breast cancer patients who choose to undergo a surgical technique, called lumpectomy, that removes the tumor but leaves the rest of the breast intact, according to an editorial in the journal by Dr. Katherine A. Vallis and Dr. Ian F. Tannock of the Princess Margaret Hospital in Toronto.
The findings, they said, reinforce that practice. All of the women in the studies had early-stage breast cancer and underwent breast-conserving surgery. In about half the cases, the patients went on to receive radiation therapy.
Besides improving survival rates, radiation significantly reduced the chance of a relapse of the disease, the study found.
The authors found that women who did not undergo radiation were about three times as likely to develop cancer in the affected breast. The relapse rate was 0.4 percent to 2.1 percent per year for women who got radiation and 1.4 percent to 5.7 percent per year for women without it.
Despite the statistical survival benefit, however, Verschraegen said radiation is not appropriate for every patient. Some women may have other conditions, such as vascular disease or previous radiation treatments, that would make radiation therapy more risky than the cancer itself.
"These results should not be generalized,'' she said.
Instead, Verschraegen said, physicians should evaluate each patient on a case-by-case basis and tailor the treatment appropriately. Patients, said Verschraegen, should take an active role in the decision process.
"If a physician after surgery says that radiation is not needed, then it is important that the patient get a second opinion,'' she said.
A National Institutes of Health panel concluded in 2000 that radiation is necessary for all women who undergo a lumpectomy. That panel said many women might also benefit from a combination of chemotherapy drugs to kill remaining cancer cells floating in the body. That post-surgery treatment is called "adjuvant therapy.''
The new study did not look at the added effect of chemotherapy on survival or recurrence rates.