Breast cancer survivors have an increased risk of developing a subsequent primary cancer compared with the general population, and women who had hormone receptor (HR)-negative breast cancer are at the greatest risk, according to the results of a retrospective study published in Cancer.
“This suggests that more targeted approaches for cancer prevention and early detection strategies are needed in survivorship care planning,” the study authors wrote.
The authors evaluated data from 12 Surveillance, Epidemiology, and End Results (SEER) registries, looking at 431,222 breast cancer survivors who were diagnosed at ages 20 to 84 years, from 1992 to 2015. The risk of subsequent primary cancer was evaluated according to HR status and age at breast cancer diagnosis.
Women with breast cancer had a higher risk of developing a subsequent primary cancer compared with the general population. There was a 44% increased risk among women with HR-negative breast cancer (standardized incidence ratio [SIR], 1.44; 95% CI, 1.41-1.47) and a 20% increased risk among women with HR-positive breast cancer (SIR, 1.20; 95% CI, 1.19-1.21).
Excess absolute risk (EAR) per 10,000 person-years ranged from 15.8 cases among survivors of late-onset HR-positive breast cancer to 69.4 cases among survivors of early-onset HR-negative breast cancer.
The most common subsequent cancer was breast cancer, accounting for 72.5% to 80% of the total EAR across HR and age groups.
The second most common subsequent cancers were ovarian cancer for early-onset HR-negative breast cancer survivors (EAR, 5.49), uterine corpus cancer for late-onset HR-positive survivors (EAR, 2.46), and lung cancer for both early-onset HR-positive survivors (EAR, 1.72) and late-onset HR-negative survivors (EAR, 3.40).
The study authors concluded that the risk of subsequent primary cancers in breast cancer survivors differs substantially by the HR subtype and age at diagnosis of first breast cancer.
Disclosures: This research was supported by the Intramural Research Department of the American Cancer Society. Please see the original reference for a full list of disclosures.
Sung H, Freedman RA, Siegel RL, et al. Risks of subsequent primary cancers among breast cancer survivors according to hormone receptor status. Cancer. Published online May 18, 2021. doi:10.1002/cncr.33602