Treatment Patterns and Mortality Risk among Elderly Patients with Metastatic Triple Negative Breast Cancer in the United States: An Observational Cohort Study Using SEER-Medicare Data ()
ABSTRACT
Purpose:
Triple negative breast cancer is more aggressive than other breast cancer
subtypes and accounts for up to 20% of all breast cancers.
Despite the poorer prognosis, there are no approved targeted treatments
available and chemotherapy remains the only choice. We examined treatment
patterns and outcomes among elderly metastatic triple-negative breast cancer
(mTNBC) patients in routine clinical practice. Methods: Patients were
identified from the linked SEER-Medicare database between 1/1/2001 and 12/31/2013 and included de novo Stage IV (n = 776) and patients with distant metastasis followed an
initial diagnosis of Stage I - III
disease (n = 1851). Kaplan-Meier analyses and time-varying Cox proportional
hazards regression were used to assess overall survival (OS). Results: The mean age at
metastatic diagnosis was 77.6 years and 1259 (48%) patients received
chemotherapy. Compared to <70 year olds, ≥70 year olds had worse performance
status, higher comorbidity burden, and were less likely to receive chemotherapy
(45% vs. 66%). Patients treated with chemotherapy had increased OS compared to
untreated patients, and the survival advantage was more pronounced in the
<70 year olds with a 6-month longer unadjusted OS compared to the ≥70 cohort (log rank p < 0.0001).
This finding was supported in the adjusted multivariate model which showed a
46% increased risk of death for untreated patients in the <70 year olds and
a 17% increased risk of death for untreated patients in the ≥70 year olds (vs.
treated). Conclusions: In this
real-world analysis, 48% of elderly mTNBC patients did not receive chemotherapy
and a greater proportion were untreated in the ≥70 year old cohort (55%).
Although the survival benefits of chemotherapy were greater in the younger
cohort, the benefits of treatment persisted in ≥70 year olds. These findings
suggest opportunities exist to improve the clinical treatment of elderly mTNBC
patients.
Share and Cite:
Satram-Hoang, S. , Bajaj, P. , Stein, A. , Cortazar, P. , Momin, F. and Reyes, C. (2019) Treatment Patterns and Mortality Risk among Elderly Patients with Metastatic Triple Negative Breast Cancer in the United States: An Observational Cohort Study Using SEER-Medicare Data.
Journal of Cancer Therapy,
10, 117-133. doi:
10.4236/jct.2019.102009.