Abstract P3-12-22: Socioeconomic position and prognosis in premenopausal breast cancer: A population-based cohort study in Denmark

Abstract

Abstract Background: To investigate how socioeconomic position (SEP) influences the effectiveness of cancer-directed treatment in premenopausal breast cancer patients in terms of breast cancer recurrence and mortality.Methods: Our cohort included all premenopausal women aged 18-55 years diagnosed with non-metastatic breast cancer and prescribed docetaxel-based chemotherapy in Denmark during 2007-2011. Population-based administrative registries provided data on SEP: marital status (married including registered partnership or single including divorced or widowed), cohabitation (cohabiting or living alone), education (low, intermediate or high), income (low, medium or high), and employment status (employed, unemployed or health-related absenteeism). For each SEP measure, we computed incidence rates, cumulative incidence proportions (CIPs) and used Poisson regression to compute incidence rate ratios and 95% confidence intervals (95% CIs) of recurrence and death. We stratified on ER status/tamoxifen to evaluate interaction.Results: Our cohort included 2,616 women; 286 (CIP: 13%) experienced recurrence and 223 (CIP: 11%) died during follow-up (median 6.6 and 7.2 years, respectively). Single women had both increased risks of recurrence (IRR: 1.45, 95% CI: 1.11-1.89) and mortality (IRR: 1.83, 95% CI: 1.32-2.52). Furthermore, we observed increased mortality in women with low education (IRR: 1.49, 95% CI: 0.95-2.33), low income (IRR: 1.37, 95% CI: 0.83-2.28), unemployment (IRR: 1.61, 95% CI: 0.83-3.13) or health-related work absenteeism (IRR: 1.80, 95% CI: 1.14-2.82), but smaller or no increased risk of recurrence. These findings were especially evident among women with ER+ tumors prescribed tamoxifen.Conclusions: Low SEP in premenopausal women with non-metastatic breast cancer was associated with increased mortality, but not always recurrence. This suggests underdetection of recurrences in certain groups. Poor prognosis in women with low SEP, especially single women, may partly be explained by tamoxifen adherence. Citation Format: Cathrine Hjorth, Per Damkier, Bent Ejlertsen, Timothy L Lash, Henrik T Sørensen, Deirdre Cronin-Fenton. Socioeconomic position and prognosis in premenopausal breast cancer: A population-based cohort study in Denmark [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-12-22.