Research Paper Volume 14, Issue 3 pp 1186—1199
Breast cancer mortality as a function of age
- 1 Division of Medical Oncology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- 2 Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- 3 Clinical Analytics, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
- 4 Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
- 5 Keck Medicine of USC, University of Southern California, Los Angeles, CA 90007, USA
Received: November 4, 2021 Accepted: January 28, 2022 Published: February 8, 2022https://doi.org/10.18632/aging.203881
How to Cite
Copyright: © 2022 Nasrazadani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: Incidence of breast cancer (BC) in US women continues to increase with age as the strongest risk factor. We aimed to compare clinical, pathological and sociological variables associated to BC diagnosis, as well as the relative mortality rates of BC patients compared to the general US population.
Methods: We performed a retrospective, single-institution study evaluating 52,509 patients diagnosed with unilateral BC at the University of Pittsburgh Medical Center (UPMC) between 1990–2020. Primary outcome was death from any cause with cancer recurrence as a secondary outcome, evaluated for 4 age groups: 20–44, 45–55, 56–69, and 70–90. A dataset of expected mortality for women in the general population over a 10-year period was constructed using the Surveillance, Epidemiology, and End Results (SEER) Program. Observed vs. expected mortality and standardized mortality ratios (SMR) for each age group were calculated.
Results: Youngest patients with BC demonstrated the highest SMR at 10-year follow-up from time of diagnosis compared to the general US population (SMR 9.68, 95% CI: 8.99to 10.42), and remained highest compared to other age groups when analysis was limited to Stage 0/1 disease (10-year SMR 3.11, 95% CI: 2.54 to 3.76). SMRs decreased with increasing age at diagnosis with an SMR <1.0 in patients diagnosed with stage 0/1 at ages 70–90 at 5-year follow-up.
Conclusions: Younger BC patients have the highest SMR which declines gradually with age. In the elderly, lower stage 0/1 SMR’s are found compared to the general population, suggesting the possibility of an associated protective effect.