TEMPORAL TRENDS AND PREDICTORS OF FIRST-LINE CHEMOTHERAPY AMONG OLDER WOMEN DIAGNOSED WITH TRIPLE-NEGATIVE BREAST CANCER IN THE UNITED STATES
Author(s)
Kehinde Adeyemi, MSc1, Coral Omene, MD PhD2, Benjamin Bates, MD MSc1, Kexin Zhu, PhD1, Elisa Bandera, MD PhD2, Farzin Khosrow-Khavar, PhD1;
1Rutgers Institute for Health, Health Care Policy and Aging Research, New Brunswick, NJ, USA, 2Rutgers Cancer Institute, New Brunswick, NJ, USA
1Rutgers Institute for Health, Health Care Policy and Aging Research, New Brunswick, NJ, USA, 2Rutgers Cancer Institute, New Brunswick, NJ, USA
OBJECTIVES: Chemotherapy remains the cornerstone of systemic treatment for older women with triple-negative breast cancer (TNBC), yet evidence on temporal trends in treatment initiation, regimen selection, and factors influencing receipt is limited. We examined national patterns of first-line chemotherapy use and predictors of initiation among older women with TNBC in the United States.
METHODS: We conducted a retrospective cohort study using SEER-Medicare data, including women aged ≥66 years diagnosed with TNBC between 2010 and 2019 with follow-up through 2020. Demographic, clinical, and tumor characteristics were summarized descriptively. Age-standardized rates of chemotherapy initiation within one year of diagnosis were estimated using Poisson regression. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with time to chemotherapy initiation.
RESULTS: The cohort included 8,598 women with TNBC, of whom 57% initiated chemotherapy. Median age was 74 years; 75% were non-Hispanic White; 91.9% had locoregional disease; and 51.6% had ≥1 comorbidity. Among 4,868 treated patients, the most common first-line regimens were docetaxel with cyclophosphamide (TC; 34.4%) and doxorubicin with cyclophosphamide followed by paclitaxel (AC+PTX; 21.4%). Use of AC+PTX increased over time, while other regimens remained stable. In adjusted analyses, older age (≥75 vs <75 years; HR 0.33, 95% CI 0.31-0.36) and higher comorbidity burden (Charlson comorbidity index [CCI] >3 vs 0: HR 0.65, 0.59-0.71; CCI =2 vs 0: HR 0.87, 0.79-0.95) were associated with lower likelihood of chemotherapy initiation, whereas advanced tumor stage (regional or distant vs localized) and higher grade were associated with increased likelihood. Regimen selection varied by patient characteristics and geographic region.
CONCLUSIONS: In this national cohort of older women with TNBC, most treated patients received guideline-supported regimens, with increasing use of AC+PTX over time. However, variation in chemotherapy initiation and regimen selection highlights persistent heterogeneity in care for older adults with TNBC.
METHODS: We conducted a retrospective cohort study using SEER-Medicare data, including women aged ≥66 years diagnosed with TNBC between 2010 and 2019 with follow-up through 2020. Demographic, clinical, and tumor characteristics were summarized descriptively. Age-standardized rates of chemotherapy initiation within one year of diagnosis were estimated using Poisson regression. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with time to chemotherapy initiation.
RESULTS: The cohort included 8,598 women with TNBC, of whom 57% initiated chemotherapy. Median age was 74 years; 75% were non-Hispanic White; 91.9% had locoregional disease; and 51.6% had ≥1 comorbidity. Among 4,868 treated patients, the most common first-line regimens were docetaxel with cyclophosphamide (TC; 34.4%) and doxorubicin with cyclophosphamide followed by paclitaxel (AC+PTX; 21.4%). Use of AC+PTX increased over time, while other regimens remained stable. In adjusted analyses, older age (≥75 vs <75 years; HR 0.33, 95% CI 0.31-0.36) and higher comorbidity burden (Charlson comorbidity index [CCI] >3 vs 0: HR 0.65, 0.59-0.71; CCI =2 vs 0: HR 0.87, 0.79-0.95) were associated with lower likelihood of chemotherapy initiation, whereas advanced tumor stage (regional or distant vs localized) and higher grade were associated with increased likelihood. Regimen selection varied by patient characteristics and geographic region.
CONCLUSIONS: In this national cohort of older women with TNBC, most treated patients received guideline-supported regimens, with increasing use of AC+PTX over time. However, variation in chemotherapy initiation and regimen selection highlights persistent heterogeneity in care for older adults with TNBC.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EPH158
Topic
Epidemiology & Public Health
Topic Subcategory
Safety & Pharmacoepidemiology
Disease
SDC: Geriatrics, SDC: Oncology