Radiation After Lumpectomy Doesn’t Improve Overall Survival
Published on November 23, 2022
Radiation along with chemotherapy and hormonal therapy to treat early-stage breast cancer after lumpectomy lowers the risk of recurrence in the same breast, depending on the cancer’s characteristics. But it doesn’t lead to better overall survival 30 years later, according to long-term results from a Scottish study.
The research was presented at the 13th European Breast Cancer Conference on Nov. 18, 2022. Read the abstract of “Randomised controlled trial of breast conserving therapy: 30 year analysis of the Scottish breast conservation trial.”
Overall survival is how long a person lives, whether or not the cancer comes back.
Common treatments for early-stage breast cancer
There are two main surgery options for early-stage breast cancer:
mastectomy, which removes the entire breast
lumpectomy — also called breast-conserving surgery — which removes the cancer, plus a rim of healthy tissue around the cancer, usually followed by radiation therapy
Depending on the cancer’s characteristics, doctors may recommend other treatments after surgery:
hormonal therapy, such as tamoxifen or an aromatase inhibitor, if the cancer is hormone receptor-positive
chemotherapy, if the cancer is large, has a high risk of recurrence, or is hormone receptor-negative
Studies from as far back as the 1970s have shown that radiation after lumpectomy reduces the risk of the cancer coming back in the same breast (called ipsilateral recurrence by doctors).
Still, few studies have more than 10 years of follow-up data. So it isn’t totally clear how long radiation after lumpectomy can reduce recurrence risk.
About the study
This study, called the Scottish Breast Conservation Trial, included 585 women ages 70 or younger diagnosed with early-stage breast cancer. The women joined the study between 1985 and 1991. All the women had lumpectomy to remove the cancer.
After surgery:
women diagnosed with hormone receptor-positive breast cancer received five years of tamoxifen
women diagnosed with hormone receptor-negative breast cancer received six cycles of CMF (cyclophosphamide, methotrexate, and fluorouracil) chemotherapy
The researchers then randomly assigned the women to one of two groups:
291 women received radiation therapy
294 women did not receive radiation therapy
The researchers followed the women for 30 years.
Ten years after the women completed radiation therapy, rates of ipsilateral recurrence were 60% lower in women who received radiation. Ipsilateral recurrence rates were:
8.8% in women who received radiation
31% in women who didn’t receive radiation
After 20 years of follow-up, ipsilateral recurrence rates were:
15.2% in women who received radiation
37.6% in women who didn’t receive radiation
After 30 years of follow-up, ipsilateral recurrence rates were:
27.8% in women who received radiation
42.7% in women who didn’t receive radiation
“What we observed is a differential effect over time,” Ian Kunkler, MA, MB, MChir, said during a press briefing at the conference. “Most of the reduction in the risk of local recurrence occurs in the first decade. In the second decade, there is no significant difference in the risk of recurrence with or without irradiation.”
Dr. Kunkler, who presented the research, is honorary professor of clinical oncology at the University of Edinburgh in Scotland
There was no difference in overall survival between women who received radiation and women who didn’t receive radiation.
After 10 years, overall survival rates were:
72.5% for women who received radiation
70.8% for women who didn’t receive radiation
After 20 years, overall survival rates were:
48.6% for women who received radiation
48.4% for women who didn’t receive radiation
After 30 years, overall survival rates were:
23.7% for women who received radiation
27.5% for women who didn’t receive radiation
“We found that there is no long-term improvement in overall survival for those women having radiotherapy,” Dr. Kunkler said in a statement. “This may be because, although radiotherapy may help to prevent some breast cancer deaths, it may also cause a few more deaths, particularly a long time after the radiotherapy, from other causes such as heart and blood vessel diseases.”
Dr. Kunkler emphasized that decisions about whether to treat early-stage breast cancer with radiation or not are not going to be different for each person diagnosed with the disease.
“It’s important to note that every woman with breast cancer is different and will have different forms of the disease,” he said. “Decisions about whether or not to have radiotherapy after surgery should be taken by patients and their doctors after careful discussion, taking into account the individual characteristics of [the] breast cancer and the likely risks of recurrence over the long term, both within and outside the breast, and of treatment-related toxicity.”
What this means for you
If you’ve been diagnosed with early-stage breast cancer, this study offers more information that you and your doctor can use when making treatment decisions. Besides the cancer’s characteristics, other factors you may consider include:
your age
any other health conditions you may have
your preferences
how close you are to treatment facilities
your personal recurrence risk and your concern about the cancer coming back
any reconstruction preferences you have
“Generally, the higher the risk of recurrence, the greater the absolute benefit of radiation,” said Marisa Weiss, MD, chief medical officer and founder of Breastcancer.org. Dr. Weiss is director of breast radiation oncology at Lankenau Medical Center in Wynnewood, Pa.
“Also, survival benefit, which [is] critically important, is not the only endpoint that’s important to women,” she continued. “For example, many women choose prophylactic contralateral mastectomy at the same time as mastectomy for the affected side, even though there is no proven survival benefit. These women are choosing this option to reduce their risk of developing another unrelated cancer, for peace of mind, and to improve the symmetry of reconstruction, not for survival.”
At Breastcancer.org, we support everyone’s right to make treatment decisions based on the characteristics of the cancer they’ve been diagnosed with, their medical history, their risk of recurrence or a new breast cancer, and their personal preferences. It’s also very important to make sure you understand all the pros and cons of any treatment or procedure you’re considering, including differences in survival rates.
Learn more about radiation therapy.