Two studies to be published today confirm that women with breast cancer who have a lumpectomy followed by radiation have the same survival rate as women who have cancerous breasts removed.
About 70 percent of women with early breast cancer were alive after 10 years, whether they had a mastectomy or breast-conserving lumpectomy with radiation, according to a review of 36 breast cancer trials that included more than 17,273 women. The review was to be published today in the New England Journal of Medicine.
Radiation therapy was associated with reduced risk of recurring breast cancer. But one-third more women in the radiation group died of other causes than did those who did not receive radiation, making overall survival rates in the two groups about the same.
Many of the women who received radiation, especially those 60 and over, died of heart attacks, said one of the study's authors, Richard Gray of Oxford University. Heavier doses of radiation, used in some of the earlier studies included in the review and known to weaken the heart, could have increased the incidence of heart attacks, Mr. Gray said. But refined radiation techniques make that less of a risk, he said.
In a second study, researchers who are part of the federally sponsored National Surgical Adjuvant Breast and Bowel Project reanalyzed data from a study of 2,105 women with early breast cancer who received either a lumpectomy, a lumpectomy followed by radiation or mastectomy.
"The finding of this reanalysis continues to show that lumpectomy followed by radiation is the appropriate therapy for most women," said the chief researcher, Dr. Bernard Fisher.
The initial findings had come under fire when it was revealed in 1994 that the study had included falsified information.
After excluding these patients and undergoing an extensive audit by the National Cancer Institute, the researchers confirmed earlier results. After 12 years of follow-up, survival rates were about the same for the three groups: 58 percent for those who had a lumpectomy alone, 59 percent for mastectomy and 63 percent for lumpectomy with radiation.
Recurrence rates in the affected breast were 10 percent in those who had lumpectomy with radiation, compared with 35 percent in those who had lumpectomy alone.