A study found that radiation therapy given after DCIS is removed by lumpectomy reduces the risk that the DCIS will come back (recurrence).
The study, the EORTC 10853 trial, was published online on Sept. 16, 2013 by the Journal of Clinical Oncology. Read the abstract of “Breast-Conserving Treatment With or Without Radiotherapy in Ductal Carcinoma In Situ: 15-Year Recurrence Rates and Outcome After a Recurrence, From the EORTC 10853 Randomized Phase III Trial.”
DCIS is the most common form of non-invasive breast cancer and is considered stage 0 cancer. DCIS usually is treated by surgically removing the cancer -- lumpectomy in most cases. After surgery, hormonal therapy medicine may be recommended if the DCIS is hormone-receptor-positive (most are). Radiation therapy also is recommended for many women.
Routine radiation therapy after DCIS was common in the past, but newer DCIS treatment guidelines say that radiation therapy after surgery doesn’t have to be given routinely to all women; some doctors wondered if giving radiation therapy after lumpectomy for DCIS was overtreatment.
The researchers who did the EORTC 10853 trial wanted to see if women who got radiation after lumpectomy to remove DCIS were less likely to have a recurrence than women who didn’t get radiation.
Between 1986 and 1996, 1,010 women diagnosed with DCIS that was completely removed by lumpectomy were randomly assigned to get either:
- no more treatment (503 women)
- radiation therapy (507 women)
The women were followed for about 16 years.
The researchers found that the women who got radiation therapy were 48% less likely to have a local recurrence of DCIS than women who didn’t get radiation therapy:
- 18% of the women who had lumpectomy and radiation therapy had a local recurrence
- 31% of the women who had only lumpectomy had a local recurrence
Local recurrence is when the breast cancer comes back in the same breast, near where the original cancer was.
Radiation therapy also reduced the risk that the women would be diagnosed with invasive breast cancer in the same breast:
- 10% of the women who had lumpectomy and radiation later were diagnosed with invasive breast cancer
- 16% of the women who had only lumpectomy later were diagnosed with invasive breast cancer
Radiation therapy after lumpectomy to remove DCIS also reduced the risk that a woman would later need a mastectomy if she had a DCIS recurrence.
There was no difference in overall survival -- the time the women lived, with or without the cancer coming back or growing -- between women who had a DCIS recurrence and women who didn’t have a DCIS recurrence. But overall survival was worse in women who were later diagnosed with invasive breast cancer.
If you’ve been diagnosed with DCIS, your doctor will recommend a treatment plan after surgery tailored to your specific recurrence risk for DCIS or invasive breast cancer. Your treatment plan may include radiation therapy, hormonal therapy, both, or neither. If you're deciding on treatments after DCIS surgery, you might want to talk to your doctor about the role of radiation therapy in your care and the results of this study. Together, you can decide on a treatment plan that makes the most sense for you and your unique situation.
The Breastcancer.org DCIS pages contain more information on DCIS symptoms, diagnosis, and treatment.