Research Activities, May 2013
Clinical tool helps to estimate predicted benefit from radiation therapy for older women with breast cancer
Although nearly half of breast cancers are diagnosed in women age 65 and older, the importance of radiation therapy (RT) after conservative surgery remains controversial for women in this age group. In general, RT is recommended for older women to achieve both prevention of recurrence and preservation of the breast. However, RT may have minimal benefit for older women who have a lower baseline recurrence risk.
A team of researchers has now developed a clinically useful tool to predict the likelihood of long-term breast preservation with and without RT. The tool, known as a "nomogram," gives scores to factors predictive of mastectomy, such as age, race, tumor size, estrogen receptor status (positive or negative), and receipt of RT to calculate a weighted total score useful for predicting 5- and 10-year mastectomy-free survival (MFS). Lymph node status was also included, given its significant interaction with RT. With a median follow-up of 7.2 years, the overall 5- and 10-year MFS rates were 98.1 percent and 95.4 percent.
The study included 16,092 women age 66 to 79 years treated with conservative surgery between 1992 and 2002. In addition to providing estimates of baseline probability of MFS, the nomogram also provides individualized estimates of potential benefit from RT. The researchers believe that since indications for RT remain unclear and continue to be debated for older patients, their clinical tool will be useful to patients and physicians when evaluating adjuvant treatment options.
The nomogram is publically available on The University of Texas MD Anderson Cancer Center Web site (www.mdanderson.org/RadiationBenefitPredictor). This study was supported in part by AHRQ (HS18565).
See "Nomogram to predict the benefit of radiation for older patients with breast cancer treated with conservative surgery," by Jeffrey M. Albert, M.D., Diane D. Liu, M.S., Yu Shen, Ph.D., and others in the August 10, 2012, Journal of Clinical Oncology 30(23), pp. 2837-2843.