Radiation may be a better option than hormonal therapy for older adults with early-stage breast cancer | SABCS 2024

Background

Historically, cancer doctors treated breast cancer very aggressively, with extensive surgeries followed by any and all treatment that might destroy cancer cells and reduce the risk of cancer coming back. Little thought was given to quality of life. Much has changed since those early days.

People with cancer now live much longer thanks to a deeper understanding of the disease and more effective treatments. They continue to share their experiences with treatment and struggles managing side effects. Doctors have responded by conducting research focused on treating cancer more successfully, with more humanity.

The current standard treatment for low-risk, early-stage, hormone receptor-positive breast cancer is lumpectomy (also called breast-conserving surgery) followed by radiation therapy and hormonal therapy. Doctors sometimes give patients the option to skip radiation therapy and move straight to hormonal therapy. Some people who make this choice find that the side effects of hormonal therapy are harder to bear than they expected and discontinue use against doctor’s advice. By then, it is too late for radiation therapy.

Results

Results from the phase III clinical trial EUROPA showed that women over 70 with early-stage, hormone receptor-positive breast cancer better tolerated radiation therapy alone over endocrine therapy alone. Based in Italy, the ongoing trial compares the two treatments, looking at quality of life after two years and rate of recurrence after five years. The results for quality of life are described here.

Participants in the study:

• Are over age 70, including 40% the study describes as frail
• Were diagnosed with luminal early hormone receptor-positive breast cancer, most with HER2 scores of 0 or 1 and tumors grade one or two
• Underwent breast-conserving surgery with or without sentinel lymph node biopsy

Over 200 participants were randomized to receive radiation therapy alone or hormonal therapy alone for this quality-of-life analysis.

• The radiation therapy group mostly received partial breast radiation (85%) versus whole breast radiation (15%).
• The hormonal therapy group is taking an aromatase inhibitor or tamoxifen.
• Quality of life was assessed by function and symptom scales and global health status.

The results for those who completed questionnaires at 24 months were:

• People receiving radiation therapy reported significantly less decline due to treatment—an average drop in 1.1 versus 10 in global health status. Global health status measures an individual’s perception of their own health and well-being on a 100-point scale.
• People in both groups reported side effects related to treatment but more so in the hormonal therapy group as compared to the radiation therapy group (85% vs. 67%). Joint pain and breast pain (but not muscle pain) were more common among participants in the radiation therapy group.
• Although still early, there was no difference in risk of breast cancer return between the two groups.

What does this mean for you?

If you or someone you care about is over 70 and recently diagnosed with early-stage, hormone receptor-positive breast cancer, you or they will likely have surgery. This study addresses what comes next. Is it enough to have just radiation therapy or just hormonal therapy? How will the choice affect your daily life and well-being?

These results suggest that radiation therapy is much easier to tolerate than hormonal therapy, although more people in the radiation therapy group reported breast pain or joint pain. The likelihood of cancer coming back was similar for people in the two groups, but it’s still early. The study team will look more closely at this outcome in three years.

If you are over 70 and newly diagnosed with the type of breast cancer being studied here, talk with your doctor about this clinical trial when you discuss your plans for treatment. Use this opportunity to ask about side effects, logistics, and cost, and to share your personal preferences.

Radiation therapy involves frequent clinic visits, while hormonal therapy can be taken at home. Still, people sometimes have trouble sticking with hormonal therapy due to side effects. Some people left this trial because they stopped taking hormonal therapy. Everyone assigned to the radiation therapy group completed radiation treatment.