Radiation therapy following lumpectomy may prevent the need for subsequent mastectomy in older women, according to the results of a study published early online in Cancer.
Of the more than 200,000 cases of breast cancer diagnosed each year in the United States, roughly 40 percent occur in women over the age of 65. As such, it is important to identify optimal treatment strategies for this older population.
Surgery for early-stage breast cancer may consist of mastectomy or lumpectomy. A mastectomy involves removal of the entire breast, whereas a lumpectomy involves removal of the cancer and some surrounding tissue. Radiation therapy following lumpectomy has been shown to reduce the risk of cancer recurrence in or near the breast. Although this strategy is often used in younger women, the standard therapy for older women is lumpectomy followed by hormonal therapies that suppress or block extrogen, such as tamoxifen or aromatase inhibitors. Researchers continue to study the potential benefit of radiation for older women.
The NCCN guidelines that recommend treating older women with lumpectomy plus hormonal therapy were based on research that indicated there was no difference in mastectomy rates or survival in older women who received radiation or hormonal therapy after lumpectomy; however, there has been no long-term follow-up data to track mastectomy rates.
To evaluate this issue, researchers from The University of Texas MD Anderson Cancer Center conducted a population-based study of a cohort of Medicare patients identified from the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) registry. The study included data from 7,403 patients ages 70-79 treated with a lumpectomy for early-stage, estrogen-positive breast cancer. All patients were diagnosed between 1992 and 2002 and were followed through 2007. Overall, 88 percent of the women underwent radiation following their lumpectomy.
The results indicated that women who underwent radiation had lower rates of mastectomy later—within 10 years of treatment, 6.3 percent of women who did not receive radiation had a mastectomy, whereas 3.2 percent of women who received radiation had a mastectomy later. Women with high-grade tumors seemed to benefit from radiation, regardless of other factors. There was, however, a subset of women who did not benefit from radiation—those 75-79 years who did not have high-grade tumors.
The researchers concluded that radiation therapy after lumpectomy was associated with a reduced risk of subsequent mastectomy in most older women with early breast cancer.
Albert JM, Pan IW, Shih YCT, et al. Effectiveness of radiation for prevention of mastectomy in older breast cancer patients treated with conservative surgery. Cancer. Published early online August 13, 2012. DOI: 10.1002/cncr.27457