T. Lash (Atlanta, AL, United States of America)
Rollins School of Public Health, Emory UniversityAuthor Of 1 Presentation
49P - Socioeconomic status and survivorship in premenopausal breast cancer patients: A population-based cohort study
Abstract
Background
Data on the influence of socioeconomic status (SES) on the effectiveness of cancer-directed treatment in premenopausal breast cancer patients is scarce.
Methods
From the Danish Breast Cancer Group (DBCG) clinical database, we assembled a cohort of all premenopausal women who were diagnosed with non-metastatic breast cancer and prescribed docetaxel-based chemotherapy during 2007–2011. The DBCG provided information on ER and HER-2 status, tumor size and lymph node status (to derive stage), histological grade, cancer-directed treatment, and recurrence. Danish population-based registries provided data on comorbidities, death, and SES at diagnosis (marital status, education, income, and employment). Follow-up began 6 months after diagnosis (to approximate the end of chemotherapy) and continued to 10 years, recurrence, death, or 31 December 2016, whichever occurred first. We computed incidence rates (IRs) per 1,000 person-years (PYs) and cumulative incidence proportions of recurrence and death. We used Poisson regression to calculate incidence rate ratios (IRRs) and 95% confidence intervals of recurrence and death according to SES, adjusting for patient, tumor, and treatment characteristics.
Results
Our cohort included 2,616 women; 286 developed recurrent breast cancer (13%, IR:18/1,000 PYs, median follow-up: 6.7 years) and 223 died (11%, IR:13/1,000 PYs, median follow-up: 7.2 years). As expected, women with ER‒ or triple negative tumors, higher stage and grade had elevated risk of recurrence and death. We observed increased risk of recurrence and death in unmarried women, mainly those with ER+ tumors prescribed tamoxifen. Women with ER+ tumors and health-related work absenteeism before diagnosis had increased mortality compared with their employed counterparts. Increased mortality in women with low SES, captured as low income or elementary school education, was explained by tumor characteristics.
Conclusions
Established prognostic characteristics were associated with recurrence and mortality in premenopausal women treated with docetaxel. Yet, we found unfavorable prognosis among unmarried women and women with health-related absenteeism from work; this may be partly related to tamoxifen adherence.
Legal entity responsible for the study
The study was approved by the Danish Data Protection Agency (AU 2016-051-000001, #808), the Regional Ethics Committee (Record no. 1-10-72-4-18) and the DBCG, the Danish Breast Cancer Group (DBCG-2019-08-20).
Funding
The Danish Cancer Society (R167-A11045-17-S2).
Disclosure
All authors have declared no conflicts of interest.