In most cases, the usual treatment for early-stage, hormone-receptor-positive breast cancer is lumpectomy to remove the cancer followed by about 6 weeks of radiation therapy (you receive treatment 5 days per week) to destroy any cancer cells that may have been left behind after surgery. This two-step approach reduces the risk of breast cancer recurrence (the cancer coming back).
But in 2004, this treatment approach changed for older women. Large studies showed that while lumpectomy plus radiation did reduce the rate of recurrence among older women, it didn’t improve overall survival. Overall survival is how long the women lived, whether or not the cancer came back. So the National Comprehensive Cancer Network modified its treatment guidelines: radiation therapy became optional for women ages 70 and older diagnosed with early-stage, estrogen-receptor-positive breast cancer who take hormonal therapy medicine for 5 years or more after lumpectomy.
Doctors then wondered if certain postmenopausal women younger than 70 also might be able to skip radiation after lumpectomy. They also wondered what the rate of recurrence was among these women who skipped radiation.
New research suggests that the rate of recurrence among women 65 and older diagnosed with early-stage, hormone-receptor-positive disease who are taking hormonal therapy is low; these women may be able to skip radiation after lumpectomy.
The study, “The PRIME II trial: Wide local excision and adjuvant hormonal therapy ± postoperative whole breast irradiation in women ≥ 65 years with early breast cancer managed by breast conservation,” was presented on Dec. 11, 2013 at the 2013 San Antonio Breast Cancer Symposium.
The PRIME II study included more than 1,300 women who joined the study between 2003 and 2009. All the women were ages 65 or older and all had been diagnosed with early-stage, hormone-receptor-positive breast cancer that hadn’t spread to the lymph nodes. All the women also were taking or were going to take 5 or more years of hormonal therapy medicine.
After lumpectomy to remove the cancer, the women were randomly assigned to get radiation therapy (658 women) or not (668 women).
After 5 years of follow-up, there was little difference between women who received radiation therapy and women who didn’t:
- 1.3% of women who got radiation therapy and 4.1% of women who didn’t had breast cancer come back in the same breast
- 0.5% of women who got radiation therapy and 0.7% of women who didn’t were diagnosed with breast cancer in the opposite breast
- 0.5% of women who got radiation therapy and 0.8% of women who didn’t had breast cancer come back in the lymph nodes near the site of the original cancer
- 97% of women who got radiation therapy and 96.4% of women who didn’t were alive whether or not the cancer had come back (overall survival)
- 97.3% of women who got radiation therapy and 94.6% of women who didn’t were alive without the cancer coming back (disease-free survival)
Thirty-five of the women who didn’t get radiation therapy and 29 women who got radiation therapy died during the study. Most of these deaths were not because of breast cancer or its treatment.
This study and others suggest that some women ages 65 and older diagnosed with early-stage, hormone-receptor-positive breast cancer who are taking 5 years or more of hormonal therapy medicine may be able to skip radiation after lumpectomy.
If you’re a postmenopausal woman and have been diagnosed with early-stage, hormone-receptor-positive breast cancer, you and your doctor will consider the characteristics of the cancer, your unique situation, your surgical options, your treatment options after surgery, and your personal preferences when creating your treatment plan. If you’ll be having lumpectomy, talk to your doctor about why radiation therapy is or isn’t recommended for you after surgery and how that decision was made.
Using the most complete and accurate information possible, you and your doctor can develop a treatment plan that makes the most sense for you. You can learn more about radiation after breast cancer surgery in the Breastcancer.org Radiation Therapy section.