The study authors sought to examine the risks of subsequent primary cancers (SPCs) among breast cancer survivors by HR status and age at diagnosis.
In general, breast cancer survivors have a greater risk of a new cancer diagnosis compared to healthy individuals, according to a recent study by the American Cancer Society. The study authors noted that the risk of new cancer diagnoses among breast cancer survivors is 20% higher for those with hormone receptor (HR)-positive cancers and 44% higher for those with HR-negative cancers compared to the general US population.1
The study authors sought to examine the risks of subsequent primary cancers (SPCs) among breast cancer survivors by HR status and age at diagnosis.2
The researchers used data from 12 Surveillance, Epidemiology, and End Results registries to identify 431,222 breast cancer survivors (at least 1 year) who were diagnosed with the disease between 20 and 84 years of age from 1992 to 2015. Additionally, the risk of SPCs was measured as the standardized incidence ratio (SIR) and the excess absolute risk (EAR) per 10,000 person-years. The researchers used Poisson regression to analyze the difference in SIRs by HR status.2
The study showed that the the risk of new cancer diagnoses among survivors was 20% higher for those with HR-positive cancers and 44% higher for those with HR-negative cancers compared with the general population. The risk difference between HR statuses was found to be statistically significant. After HR-negative cancer, the highest risk was driven by acute nonlymphocytic leukemia and breast, ovarian, peritoneal, and lung cancers, according to the study.2
By age at diagnosis, the total EAR per 10,000 person-years ranged from 15.8 among survivors of late-onset HR-positive disease to 69.4 among early-onset HR-negative survivors. Additionally, subsequent breast cancer represented 73% to 80% of the total EAR.
After breast cancer, the greatest EARs were ovarian cancer among early-onset HR-negative survivors, lung cancer among early- and late-onset HR-negative survivors, and uterine corpus cancer among late-onset HR-positive survivors, according to the study.2
"Differential risk of subsequent cancer according to survivor characteristics highlights that more targeted approaches for cancer prevention and early-detection strategies are needed in survivorship care planning to mitigate the burden of subsequent cancers in the growing population of survivors," the study authors said in the press release.1
The study authors concluded that risks of SPCs after breast cancer vary greatly by subtype and age, which the authors noted indicates a need for more targeted approaches to cancer prevention and early-detection strategies in survivorship care planning.2
1. More targeted cancer prevention and early detection strategies needed in breast cancer survivorship. EurekAlert! Published May 18, 2021. Accessed May 18, 2021. https://www.eurekalert.org/pub_releases/2021-05/acs-mtc051421.php
2. Sung H, Freedman RA, Siegel RL, et al. Risks of subsequent primary cancers among breast cancer survivors according to hormone receptor status. Cancer. May 18, 2021. Doi: https://doi.org/10.1002/cncr.33602