Some Older Breast Cancer Patients Could Skip Radiation
Many older women with newly diagnosed breast cancer might safely avoid adjuvant radiation therapy, according to a study reported here.
Radiation therapy did not reduce the risk of local recurrence beyond the benefit afforded by tamoxifen alone in women older than 60 with luminal A breast cancer or in women with grade I-II luminal A breast cancer.
Avoiding radiation therapy in those subgroups could lead to a $400 million savings in healthcare costs, Fei-Fei Liu, MD, reported at the American Association for Cancer Research (AACR) meeting.
“Luminal A lymph node-negative breast cancer is estimated to account for about 25% of all newly diagnosed breast cancer in North America every year,” Liu, of the University of Toronto, said during an AACR press briefing. “These patients can avoid unnecessary treatments.”
“We estimated a savings of $20 million annually in Ontario if radiation therapy were avoided in early luminal A breast cancer. Extrapolating the figures to the United States resulted in a savings of about $400 million per year,” Liu added.
The preferred approach to treating early breast cancer consists of surgery followed by systemic therapy and radiation therapy. Most women can tolerate this approach to treatment, but the therapies can cause side effects, which can be severe in some cases, Liu noted.
Additionally, most radiation therapy schedules are inconvenient and require daily travel, or travel on most days of the week until the treatment is completed. Younger patients also face a risk of secondary malignancies following radiation therapy.
Radiation therapy - also called radiotherapy - is a highly targeted, highly effective way to destroy cancer cells in the breast that may stick around after surgery. Radiation can reduce the risk of breast cancer recurrence by about 70%. Despite what many people fear, radiation therapy is relatively easy to tolerate and its side effects are limited to the treated area.
After breast surgery, radiotherapy can lower the risk of the cancer coming back in the breast.
How and where you have treatment
You have your treatment in the hospital radiotherapy department. You may have treatment once a day, from Monday to Friday, with a rest at the weekend. This means you will have to travel to the hospital every weekday. The course of treatment usually lasts either 3 or 5 weeks.
At your first visit you lie under a CT scanner or a large machine called a simulator. The doctors use this to plan your treatment. You will have one or more small tattoos made on your skin. The radiographers use these to line up the radiotherapy machine accurately each time. You may also have marks drawn on your body with a felt tip pen.
Each treatment only takes a few minutes. The treatment doesn’t hurt, and it does not make you radioactive.
More rarely radioactive tubes are put into the breast tissue area of the breast where the cancer was removed. This is called internal radiotherapy or brachytherapy.
As previously reported, the standard of care for early breast cancer (tamoxifen plus radiation therapy) was compared with tamoxifen alone in prospective clinical trial involving patients with T1 or T2, node-negative breast cancer (N Engl J Med 2004;351:963).
The primary endpoint was ipsilateral recurrence at 10 years. When the study ended, women who did not receive radiation therapy had almost a three-fold higher incidence of recurrence (13.8% versus 5.3%, P<0.0001).
External radiotherapy
The treatment is given in the hospital radiotherapy department as a series of short daily sessions. Each treatment takes 10–15 minutes and they are usually given Monday–Friday with a rest at the weekend. Your doctor will discuss the treatment and possible side effects with you.
A course of radiotherapy for breast cancer is usually given for three weeks. Some women may be given radiotherapy in different ways or over a different timescale as part of a clinical trial.
Radiotherapy is normally given to the whole breast area. Depending on the risk of the cancer coming back, it may also be given to areas of lymph nodes close to the breast. This includes the armpit and the area just above the collarbone and by the breastbone (sternum).
External radiotherapy does not make you radioactive and it is safe for you to be with other people, including children, after your treatment.
Since the trial ended, breast cancer researchers have learned that invasive breast cancer is not a single disease but comprises at least five or six subtypes, said Liu.
To assess the impact of radiation on breast cancer subtypes, investigators returned to the database and tissue bank for the randomized trial. Molecular subtype was determined for 304 tumors by means of immunohistochemistry and tissue microarrays.
Subtyping included analysis of estrogen receptor, progesterone receptor, the Ki-67 proliferation marker, HER2, epidermal growth factor receptor, and cytokeratin (CK) 5/6.