(RxWiki News) The need for radiation treatment after a lumpectomy has been studied for years. Current treatment guidelines say radiation is not necessary for older women with early breast cancer. A new study suggests that this may not be the case.
Radiation treatment for breast cancer following this breast conserving surgery may help older women with early stage high grade tumors.
It may also prevent the need for the total removal of the breast down the road.
"Ask your doctor about the stage and tumor type of your cancer."
That's what a study led by Benjamin Smith, MD, assistant professor of radiation oncology at The University of Texas MD Anderson Cancer Center, has learned.
“Our study provides an additional layer of nuance to help clinicians and patients make more informed decisions about which patients are most suitable for lumpectomy alone without radiation therapy," Dr. Smith told dailyRx in an email.
In 2004, the National Comprehensive Cancer Network changed its guidelines. Currently, radiation is not recommended for women over the age of 70 with early breast cancers that are fueled by estrogen (estrogen receptor positve - ER+).
Instead, after surgery these ladies are told to take drugs that block estrogen - Arimidex (anastrozole), Aromasin (exemestane) or Femara (letrozole).
To study the basis of these guidelines, Dr. Smith conducted a large follow-up study involving nearly 7,500 women between the ages of 70-79. He and colleagues focused on how many women eventually needed mastectomies.
"Our study strongly suggests that women age 75 and older with low to intermediate grade, estrogen receptor positive, pathologic stage T1 N0 invasive breast cancer have outstanding outcomes even if radiation is not given," said Dr. Smith, who is the study's corresponding author.
"In contrast, our findings also illustrate that those patients with high grade tumors derive a significant benefit from radiation, even if their tumor has otherwise favorable characteristics."
The women in the study were Medicare patients who were in the Surveillance, Epidemiology and End Results (SEER) registry. All of them had been diagnosed between 1992 and 2002, and they were followed until 2007.
Of the original 7,403 women in the study, 88 percent (6,515) had had radiation after their lumpectomy. Twelve percent of the ladies (889) did not have radiation.
Within 10 years of their treatment, 6.3 percent of the women who had not received radiation underwent a mastectomy, which was likely needed because the cancer came back.
In contrast, only 3.2 percent of the women who had received radiation needed a mastectomy within 10 years.
Radiation was particularly helpful for women who had high grade tumors.
"This information can help make sure that patients receive the right treatment for their tumor and help avoid both under-treatment and over-treatment," Dr. Smith said.
This research was published in the August issue of the journal Cancer.
The study was funded, in part, by research grants from Varian Medical Systems, US Department of Health and Human Services and the National Cancer Institute.
None of the authors declared any conflicts.
