Nomogram to Predict the Benefit of Radiation for Older Patients With Breast Cancer Treated With Conservative Surgery

Abstract

A B S T R A C T PurposeThe role of radiation therapy (RT) after conservative surgery (CS) remains controversial for older patients with breast cancer. Guidelines based on recent clinical trials have suggested that RT may be omitted in selected patients with favorable disease. However, it is not known whether this recommendation should extend to other older women. Accordingly, we developed a nomogram to predict the likelihood of long-term breast preservation with and without RT. MethodsWe used Surveillance, Epidemiology, and End Results-Medicare data to identify 16,092 women age 66 to 79 years treated with CS between 1992 and 2002, using claims to identify receipt of RT and subsequent mastectomy. Time to mastectomy was estimated using the Kaplan-Meier method. Cox proportional hazards models determined the effect of covariates on mastectomy-free survival (MFS). A nomogram was developed to predict 5-and 10-year MFS, given associated risk factors, and bootstrap validation was performed. ResultsWith a median follow-up of 7.2 years, the overall 5-and 10-year MFS rates were 98.1% (95% CI, 97.8% to 98.3%) and 95.4% (95% CI, 94.9% to 95.8%), respectively. In multivariate analysis, age, race, tumor size, estrogen receptor status, and receipt of RT were predictive of time to mastectomy and were incorporated into the nomogram. Nodal status was also included given a significant interaction with RT. The resulting nomogram demonstrated good accuracy in predicting MFS, with a bootstrap-corrected concordance index of 0.66. ConclusionThis clinically useful tool predicts 5-and 10-year MFS among older women with early breast cancer using readily available clinicopathologic factors and can aid individualized clinical decision making by estimating predicted benefit from RT.

Radiation Treatment in Older Patients: A Framework for Clinical Decision Making

“…6 Results indicate that although a less aggressive radiation treatment course may increase IBR risk modestly compared with whole-breast irradiation, low absolute IBR risk justifies consideration of these approaches. [7][8][9] To promote personalized decision making for older women with breast cancer, our group recently developed a nomogram to predict radiation treatment benefit. 7,10 Similarly, for low-and intermediate-risk prostate cancers diagnosed in older men, 11 local therapy such as radical prostatectomy is unlikely to improve survival in men age Ն 65 years.…”

“…[7][8][9] To promote personalized decision making for older women with breast cancer, our group recently developed a nomogram to predict radiation treatment benefit. 7,10 Similarly, for low-and intermediate-risk prostate cancers diagnosed in older men, 11 local therapy such as radical prostatectomy is unlikely to improve survival in men age Ն 65 years. In contrast, radical prostatectomy does seem to improve survival in men age Ͻ 65 years.…”

Loco-Regional Therapy for Early and Advanced Breast Cancer in the Molecular Era

“…A multivariate analysis was performed using known prognostic factors like age, race, tumor size, estrogen receptor status, and use of radiation therapy and the nomogram conferred the highest risk of subsequent local failure to ER negative status. (HR 2.27 95 % CI, 1.85-2.78, P<.001) [6].…”

“…Albert et al [6] developed a nomogram to predict mastectomy free survival, using the data of 16,092 women from the SEER database. A multivariate analysis was performed using known prognostic factors like age, race, tumor size, estrogen receptor status, and use of radiation therapy and the nomogram conferred the highest risk of subsequent local failure to ER negative status.…”

Radiation Therapy in the Elderly with Early Stage Breast Cancer: Review and Role of New Technology

“…Various tools have been created to help determine the risk of mastectomy free survival in the elderly population including the following tool available through MDACC: www.mdanderson.org/ RadiationBenefitPredictor [7]. The greatest difficulty in estimating the benefit of treatment to a women over the age of 70 is trying to estimate each individual patient's life expectancy.…”