SABCS: 'Sandwich' Therapy Touted for Early Breast Cancer (en inglés)
If early-stage breast cancer is going to be treated with both chemotherapy and external beam radiation therapy, chemotherapy usually is given first. Radiation usually starts after chemotherapy is done.
A study suggests that giving radiation therapy at the same time as chemotherapy -- in between cycles or even during cycles -- offers the same benefits as the traditional approach (chemotherapy followed by radiation) in less time. The results were presented at the 2010 San Antonio Breast Cancer Symposium (SABCS).
Chemotherapy usually is given in cycles -- a specific period of treatment followed by a period of recovery. For instance, you may get chemotherapy on the first day of the cycle and then have a few weeks of recovery with no treatment. The treatment day and the recovery weeks make up one cycle. Or you may get chemotherapy for several days in a row, or every other day, and then have a recovery period. A complete chemotherapy regimen is made up of several cycles. The number of cycles in a regimen and the total time of each regimen varies depending on the medicines used, but most regimens take 3 to 6 months to complete.
In the standard treatment sequence, radiation therapy doesn't start until the chemotherapy regimen is done. The traditional external beam radiation therapy treatment schedule usually requires daily trips to the hospital or cancer center -- usually 5 days a week for 4 to 6 weeks.
For many women, the time required to complete the standard sequence of chemotherapy followed by radiation therapy can be very inconvenient and can dramatically reduce quality of life when a woman is trying to heal and get on with her life.
In this study, 2,296 women diagnosed with early-stage breast cancer were getting care at 49 U.S. cancer centers. More than half the women had lumpectomy and the others had mastectomy. All the women were scheduled to get chemotherapy and radiation therapy after surgery. Doctors call treatments given after surgery to reduce the risk of the cancer coming back (recurrence) adjuvant treatments.
Half the women got the standard sequence: chemotherapy first, followed by external beam radiation therapy (sequential therapy).
The other half of the women got radiation therapy at the same time as chemotherapy (synchronous therapy). Because the women were treated with a variety of chemotherapy regimens and radiation dosing schedules, the exact schedules for synchronous therapy were different for each woman. Some women got radiation therapy in between chemotherapy cycles (sandwich therapy). Other women got radiation therapy during a chemotherapy cycle (concurrent therapy).
All the women who got synchronous therapy finished chemotherapy and radiation therapy 4 to 6 weeks sooner than the women who got sequential therapy.
Synchronous therapy's shorter treatment time could be an attractive option for some women. Still, the researchers wanted to be sure that synchronous therapy offered the same benefits as traditional sequential therapy.
Half the women were followed for 9 years or more after they completed adjuvant chemotherapy and radiation therapy; the other half of the women were followed for less time. On average, the women who got synchronous therapy did at least as well as the women who got traditional sequential therapy.
After about 9 years, 5.4% of the women who got synchronous therapy had a cancer recurrence in the breast area (called locoregional recurrence) compared to 7.4% of the women who got traditional sequential therapy.
At 5 years of follow-up:
- 83% of the women who got synchronous therapy were alive and had no recurrence (disease-free survival) compared to 82% of the women who got sequential therapy
- 79% of the women who got synchronous therapy were alive (overall survival) compared to 78% of the women who got sequential therapy
Many women who get radiation therapy to treat breast cancer have a skin reaction in the area targeted by the radiation. Often the reaction is much like sunburn, with mild to moderate pink color or redness, enlargement of small blood vessels in the skin (telangiectasia), itching, burning, soreness, and possible peeling. In this study, women who got synchronous therapy had slightly more skin reactions to radiation therapy, including telangiectasia.
The synchronous schedule for adjuvant chemotherapy and radiation therapy could be a time-saving scheduling option for women being treated for early-stage breast cancer, while still offering the same benefits as traditional sequential therapy. Another promising time-saving radiation therapy option is intraoperative radiation therapy (IORT). In IORT, radiation is given during breast cancer surgery as a high, single dose directly to the area where the cancer used to be.
While synchronous therapy and IORT are considered experimental, other alternatives to traditional external beam radiation therapy that deliver more focused radiation therapy over a shorter period of time are already approved by the U.S. Food and Drug Administration to treat breast cancer. These include:
- two types of internal radiation therapy (brachytherapy)
- multi-catheter internal radiation
- balloon-catheter internal radiation (brand name: MammoSite)
- 3-D conformal external beam radiation
You can learn more about these radiation therapy options in the Breastcancer.org Radiation Therapy section.
