Radiation After Lumpectomy Doesn’t Improve Overall Survival for Certain Older Women
Radiation after lumpectomy for small, early-stage, hormone receptor-positive breast cancer markedly decreased the risk of local recurrence — cancer coming back in the same area — but didn’t improve overall survival in women ages 65 and older, according to a study.
The research was published in the Feb. 16, 2023 issue of The New England Journal of Medicine. Read the abstract of “Breast-Conserving Surgery with or without Irradiation in Early Breast Cancer.”
Overall survival is how long a person lives, whether or not the cancer comes back or grows.
Breast-conserving surgery is another name for lumpectomy.
About the study
Radiation therapy can cause side effects such as skin irritation and fatigue. It also requires a near daily commitment for three to seven weeks, depending on the treatment schedule. So researchers want to see if women of a certain age diagnosed with certain types of breast cancer might be able to skip radiation.
Called the PRIME II trial, this study included 1,326 women ages 65 and older diagnosed with early-stage, hormone receptor-positive, node-negative breast cancer that was 3 centimeters or smaller in size. Node negative means there is no cancer in the lymph nodes near the breast. All the women had lumpectomy to remove the cancer and were prescribed at least five years of hormonal therapy after surgery.
The women lived in the United Kingdom, Greece, Australia, and Serbia.
The women were diagnosed between April 2003 and December 2009.
It’s important to point out that the researchers didn’t know several important pieces of information about the women or the breast cancers, including:
HER2 status of the cancer
the women’s family history of breast cancer
any genetic testing results
The researchers randomly split the women into two groups:
658 women received radiation after lumpectomy
668 women received no radiation after lumpectomy
After 10 years of follow-up:
9.5% of the women who didn’t receive radiation had a local recurrence
0.9% of the women who received radiation had a local recurrence
This difference was statistically significant, which means that it was likely due to the difference in radiation treatment and not just because of chance.
The researchers also looked at local recurrence in women who didn’t receive radiation and took the full five years of hormonal therapy versus women who stopped taking hormonal therapy early. The results showed that women who stopped taking hormonal therapy early had a higher risk of local recurrence.
Distant recurrence rates were:
1.6% for women who didn’t receive radiation
3% for women who received radiation
Distant, or metastatic, recurrence means the cancer came back in a part of the body away from the breast, such as the bones or liver. The risk of distant recurrence was actually higher in women who received radiation.
Disease-free survival rates were:
68.9% for women who didn’t receive radiation
76.3% for women who received radiation
Disease-free survival means the women were alive and had no cancer recurrence.
Overall survival rates were:
80.8% for women who didn’t receive radiation
80.7% for women who received radiation
Among all the women in the study:
16 women who didn’t receive radiation died from breast cancer
15 women who received radiation therapy died from breast cancer
“Radiotherapy can place a heavy burden on patients, particularly older ones,” Ian Kunkler, professor of clinical oncology at the University of Edinburgh and lead author of the study, said in a statement. “Our findings will help clinicians guide older patients on whether this particular aspect of early breast cancer treatment can be omitted in a shared decision-making process, which weighs up all the risks and benefits.”
What this means for you
If you’re 65 or older and have been diagnosed with early-stage, hormone receptor-positive breast cancer, the results of this study are encouraging, but there are several things to keep in mind.
The measuring stick for this study was overall survival. The value of reducing the risk of local recurrence was discounted.
Although radiation therapy didn’t affect overall survival, it did reduce the risk of local recurrence by nearly 90%. Overall survival is important, of course, but many women want to do everything they can to keep the risk of cancer coming back as low as it can be. As the results of this study show, radiation therapy is very effective in reducing the risk of recurrence.
It’s not clear how many women took the full five years of hormonal therapy. Taking hormonal therapy after surgery also reduces the risk of hormone receptor-positive breast cancer coming back. Women who didn’t take the full five years of hormonal therapy and also didn’t receive radiation had a higher risk of local recurrence than women who took the full course of hormonal therapy and didn’t receive radiation.
“Many women never want to see cancer again,” said Marisa Weiss, MD, Breastcancer.org chief medical officer and founder. “A tenfold drop in the risk of local recurrence is very important to most women, even if overall survival isn’t improved. Most women are prepared to do what is reasonable and effective to lower the risk of another diagnosis.
“We need to protect women’s right to choose and access the best treatments for their own unique situation, together with her own team of doctors, privately,” she added.
— Last updated on May 25, 2023 at 2:46 PM