Abstract PD10-07: Patient reported outcomes and early discontinuation of adjuvant endocrine therapy according to neighborhood poverty rate
Authors: Sedhom Ramy , Blackford Amanda , Lim David , Ensminger Jennifer , Snyder Claire , Stearns Vered , Smith Karen Lisa 
Published: March 2020

Abstract
Introduction: Early discontinuation (DC) of adjuvant endocrine therapy (AET) for hormone receptor positive breast cancer (BC) is associated with increased risk of recurrence and death. Symptoms and low socioeconomic status (SES) have both previously been associated with early AET DC. Prospective collection of patient-reported outcomes (PRO) is increasingly used in oncology practice, and can lead to improvements in quality of life and survival in advanced cancer. Compared to patients of high SES, those of low SES report higher symptom burden in multiple clinical settings. Whether PRO reporting during AET differs according to SES is unknown.
Methods: We enrolled women initiating AET for stage 0-III BC in a prospective clinic-based cohort from March 2012 to Dec 2016. At baseline (BL), 3, 6, 12, and 24 months (mo), participants completed these PROs online: FACT-ES, MOS Sexual Problems, and NIH PROMIS measures for pain interference, fatigue, depression, anxiety, physical function and sleep disturbance. Neighborhood poverty (NP) rate, a surrogate for SES based on US Census estimates of the % of persons in a zip code below the federal poverty line, was categorized as 0-5% (low), &gt;5-10% (moderate) and &gt;10% (high). We assessed AET DC and cited reason for DC by chart review. Baseline characteristics were compared between NP groups using Fisher’s exact and t-tests. Changes in mean PRO scores from BL to follow-up (FU) time points for each NP group were estimated simultaneously from a linear mixed effects regression model with a random intercept for each patient. We evaluated differences in changes in mean scores for all 8 PRO measures over time according to NP group with an interaction test. Statistical significance of p &lt; 0.05/8 = 0.006 was used, adjusting for multiple comparisons.
Results: Among 320 women, mean age was 61 (range 26-90), 83% were White, 10% Black, 65% were post-menopausal and 84% had Stage I-II BC. NP categorization was: 97 (30.3%) low, 127 (39.7%) moderate and 96 (30%) high. Mean stage distribution, and proportions of participants who had mastectomy, chemotherapy and radiation did not differ by NP group. There were fewer post-menopausal women in the moderate/high NP groups (61%) compared to the low NP group (72%, p=0.04). The proportion of Black participants increased with NP group (low 5%, moderate 10%, high 16%, p=0.04). Overall, 180 (56%) were on an aromatase inhibitor (AI) and 140 (44%) were on tamoxifen. There was more AI use in the low NP group (64%) compared to the moderate/high NP groups (53%, p=0.08). At BL, there were no differences in mean score on any PRO by NP group. For all NP groups, endocrine symptoms worsened at all FU times (all p&lt;0.05) and physical function improved at most FU times. Compared to BL, mean changes in pain interference over time differed by NP group (interaction p=0.005), with less pain interference at 6 and 12 mo in the moderate/high NP groups and no significant change in the low NP group. Mean changes in other PROs did not differ by NP group. At median FU of 41 mo (range 3-75), the proportion of participants who discontinued AET due to side effects/intolerance was similar across NP groups (low 12.6%, moderate 16%, high 17%, p=0.67).
Discussion: We found that changes in PROs during AET were similar across SES based on NP rates with the exception of less reported pain interference over time in participants of lower SES. The lack of improvement in pain interference in participants of higher SES may be attributable to arthralgias due to more frequent AI use. Despite differences in pain interference, early DC of AET due to side effects/intolerance did not differ by SES in this cohort. Our findings suggest that PROs are generally similar among early BC patients of varied SES receiving AET and that factors other than symptoms may explain the previously reported association between early DC and low SES.
Citation Format: Ramy Sedhom, Amanda Blackford, David Lim, Jennifer Ensminger, Claire Snyder, Vered Stearns, Karen Lisa Smith. Patient reported outcomes and early discontinuation of adjuvant endocrine therapy according to neighborhood poverty rate [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD10-07.