Among women aged 70 or older with Stage I, estrogen receptor-positive breast cancer, treatment with lumpectomy and tamoxifen resulted in a higher rate of cancer recurrence but similar overall survival as treatment with lumpectomy, tamoxifen, and radiation therapy. These results, which will be presented at the 2010 annual meeting of the American Society of Clinical Oncology, suggest that some older women may be able to forego radiation therapy without adversely affecting survival.
Surgery for early-stage breast cancer typically involves either mastectomy or lumpectomy. A mastectomy involves removal of the entire breast, whereas a lumpectomy involves removal of the cancer and a portion of surrounding tissue. Because a lumpectomy alone is associated with a higher rate of cancer recurrence than mastectomy, patients who elect to have a lumpectomy are generally also treated with radiation therapy. The combination of lumpectomy and radiation is called breast-conserving therapy. Studies have shown that breast-conserving therapy is associated with a lower risk of local cancer recurrence than lumpectomy alone.
Although the addition of radiation therapy to lumpectomy reduces the risk of local cancer recurrence, radiation therapy typically takes place over several weeks and requires a large commitment of time from the patient. This has prompted interest in whether there are certain groups of women with early breast cancer who can safely forego radiation therapy after lumpectomy.
The current study involved 636 women aged 70 or older with Stage I, estrogen receptor-positive breast cancer. After lumpectomy, women were assigned to additional treatment with tamoxifen alone or tamoxifen plus radiation therapy.
Women have now been followed for over 10 years.
- The risk of cancer recurrence in the same breast was lower among women who received radiation therapy: a local cancer recurrence developed in 2% of women treated with tamoxifen and radiation therapy and 8% of women treated with tamoxifen alone.
- Breast cancer-specific and overall survival were similar in the two study groups: 10-year overall survival was 61% among women treated with tamoxifen and radiation therapy and 63% in women treated with tamoxifen alone.
These results suggest that among older women treated with lumpectomy and tamoxifen for Stage I, estrogen receptor-positive breast cancer, skipping radiation therapy increases the risk of local cancer recurrence but does not adversely affect overall survival.
Older women with early breast cancer may wish to talk with their doctor about the risks and benefits of all treatment options.
Reference: Hughes KS, Schnaper LA, Cirrincione C et al. Lumpectomy plus tamoxifen with or without irradiation in women age 70 or older with early breast cancer. To be presented at the 2010 annual meeting of the American Society of Clinical Oncology. June 4-8, 2010. Chicago, IL. Abstract 507.