For women diagnosed with early-stage breast cancer, lumpectomy followed by radiation therapy has been shown to be as effective as mastectomy without radiation for removing the cancer AND minimizing the risk of the cancer coming back (recurrence). Doctors call radiation therapy given after surgery adjuvant radiation therapy or adjuvant radiotherapy. Adjuvant radiation therapy can destroy any cancer cells that may have been left behind after surgery, making recurrence less likely. Almost all women get adjuvant radiation therapy after lumpectomy. Most doctors believe adjuvant radiation therapy's greatest value is to reduce the risk of the cancer coming back in the breast area (locoregional recurrence).
A very large study has found that radiation therapy after lumpectomy offers more benefits and keeps offering benefits much longer after diagnosis than doctors realized. Recurrence risk was cut in half when adjuvant radiation therapy was included in the treatment plan for women diagnosed with early-stage breast cancer who had lumpectomy. Adjuvant radiation therapy also reduced the risk that the cancer would come back in parts of the body away from the breast (metastatic recurrence) -- not just locoregional recurrence risk -- and improved long-term overall survival. The results were published in the Oct. 15, 2011 issue of The Lancet.
A meta-analysis is an analysis of the results of a number of completed studies. This meta-analysis looked at 17 studies on the benefits of adjuvant radiation therapy after lumpectomy involving more than 10,000 women; the 17 studies compared the outcomes of women who got adjuvant radiation therapy to women who didn't. Half of the women were followed for more than 9.5 years and the others were followed for a shorter time. Some of the women were followed for more than 20 years.
In the 10 years after surgery:
- 19.3% of women who got adjuvant radiation therapy had a cancer recurrence
- 35% of women who didn't get radiation therapy had a recurrence
In the 15 years after surgery, researchers projected that:
- 21.4% of women who got adjuvant radiation therapy did or would have a recurrence and die as a result
- 25.2% of women who didn't get radiation therapy did or would have a recurrence and die as a result
The results mean that for every four recurrences prevented by adjuvant radiation therapy, one death from breast cancer also would be prevented.
It's important to know that many of the women followed in the 17 studies analyzed had clear lymph nodes, meaning the cancer hadn't spread to nearby lymph nodes. These women were considered at low risk for breast cancer recurrence. Still, the results strongly suggest that adjuvant radiation therapy after lumpectomy can reduce the risk of recurrence and improve survival for all women diagnosed with early-stage breast cancer, no matter their estimated risk of recurrence at the time of surgery.
The results also strongly support doctors' current understanding that lumpectomy followed by radiation therapy is a very good alternative to mastectomy for many women.
If you've been diagnosed with early-stage breast cancer, you and your doctor will consider the characteristics of the cancer, your unique situation, your surgical options, and your treatment options after surgery when creating your treatment plan. If you choose lumpectomy, it's very likely that radiation will be recommended after surgery. If radiation therapy isn't recommended, you may want to talk to your doctor about this study and ask why adjuvant radiation therapy isn't recommended for you.
You can learn more about radiation after breast cancer surgery in the Breastcancer.org Radiation Therapy section.