Abstract
Abstract Cancer and/or treatment-related pain is a critical quality of life issue for cancer survivors. In a prospective longitudinal study of 1,000 breast cancer patients (enrolled during 2011-2013), we examined risk factors for pain among women undergoing adjuvant radiotherapy (RT). A pain score was assessed as a mean of four pain severity items (i.e., pain at its worst, least, average, and now) from the Brief Pain Inventory with an 11-point numeric rating scale (0-10) at baseline and post-RT. The study sample consists of 623 whites, 280 black/African Americans, 64 Hispanic whites, and 33 others. The mean age was 58.1 ±10.8 years and the mean body mass index (BMI) was 30.7 ±7.0 kg/m2. The mean pain score was 1.5 ±1.0 (baseline) and 2.5 ±1.8 (post-RT). In multivariable linear regression analysis (n= 863), post-RT pain score was significantly associated with baseline pain score (β= 0.39 per 1 point increment, p< 0.0001), age (β= -0.03 per 1 year increment, p< 0.001), BMI (β= 0.03 per 1 kg/m2 increment, p= 0.004), current smoking status (β= 0.57, p= 0.022), conventional RT fractionation (β= 0.48, p= 0.033), and pain medication use (β= 1.85, p< 0.0001). Further stratified analysis showed that post-RT pain score was associated with baseline pain score, age, BMI, and mastectomy among patients who did not use pain medication (n= 625); however, it was associated with baseline pain score and conventional RT fractionation among patients who did use pain medication (n= 238). Altogether, baseline pain score is the most significant and robust risk factor for post-RT pain, and conventional RT fractionation is a significant risk factor post-RT pain only among those who experienced more pain. These risk factors may help identify individuals at-risk for post-RT pain; thus, this information may help guide these high-risk individuals in their RT decision-making processes, such as considering a hypo-fractionated RT schedule. Citation Format: Eunkyung Lee, Shannon Snyder, Edward Ip, Jean L. Wright, Jennifer J. Hu. Risk factors for post-radiotherapy pain in a multi-racial ethnic population of breast cancer patients: a prospective study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3290.