by Jifang Zhou, Jenilee Cueto, Naomi Y. Ko, Kent F. Hoskins,
Nadia A. Nabulsi, Alemseged A. Asfaw, Colin C. Hubbard, Debanjali Mitra,
Gregory S. Calip, Ernest H. Law
The Breast: VOLUME
59, P367-375, OCTOBER 01, 2021
Background
Multiple independent risk factors are associated with the
prognosis of hormone receptor-positive (HR+), human epidermal growth factor
receptor 2-negative (HER2-) breast cancer (BC), the most common BC subtype.
This study describes U.S. population-based recurrence rates among older,
resected women with HR+/HER2- early BC.
Methods
We conducted a retrospective cohort study of older women
diagnosed with incident, invasive stages I-III HR+/HER2- BC who underwent
surgery to remove the primary tumor using the Surveillance, Epidemiology, and
End Results (SEER)-Medicare Linked Database (2007–2015). SEER records and
administrative health claims data were used to ascertain patient and
tumor-specific characteristics, treatment, and frailty status. Cumulative
incidences of BC recurrence were estimated using a validated algorithm for
administrative claims data. Multivariable Fine-Gray competing risk models
estimated adjusted subdistribution hazards ratios and 95 % confidence
intervals for associations with BC recurrence risk.
Results
Overall, 46,027 women age ≥65 years were included in our
analysis. Over a median follow up of 7 years, 6531 women experienced BC
recurrence with an estimated 3 and 5-year cumulative incidence rates of
10 % and 16 %, respectively. Higher 3- and 5-year cumulative
incidences were observed in women with larger tumor size (5+ cm, 21 % and
28 %), lymph node involvement (4+ nodes, 27 % and 37 %), and
with frail health status at diagnosis (13 % and 20 %). Independent of
these clinical risk factors, Black, Hispanic and American Indian/Alaskan Native
women had significantly increased BC recurrence risks.
Conclusions
Rates of recurrence in HR+/HER2- early BC differs by several
patient and clinical factors, including high-risk tumor characteristics. Racial
differences in BC outcomes deserve continued attention from clinicians and
policymakers.
