Do cancer survivors have an increased risk of developing subsequent cancer? A population-based study.

Abstract

Background: The number of cancer survivors has steadily increased due to earlier detection and more effective therapies. Do all types of cancer survivors have an increased risk of developing subsequent cancers compared with the general population?

Methods: Patients diagnosed with malignant cancer between January 2000 and December 2021 were included from the SEER 17 Registries (excl AK) database. Events were defined as subsequent cancer at any site according to ICD-O-3/WHO 2008. The observed and expected numbers of subsequent cancers were retrieved, and observed/expected (O/E) ratios and excess risks were calculated to assess the risk of developing subsequent cancers in cancer survivors compared with the United States general population within the same period. We obtained standard incidence ratios for the entire cohort and stratified the data by demographics, treatment, and cancer type.

Results: Our findings indicate that compared with the general population, cancer survivors have a 16% greater risk of developing subsequent cancers (p < 0.05). All the subgroups also presented a significantly greater risk of developing subsequent cancers, even after stratification by demographics, treatment, and historic stage. Male patients with prostate cancer had a 31% lower risk of developing subsequent cancers, whereas female patients with lung and bronchus cancer presented a 93% increased risk.

Conclusion: Our findings suggest that nearly all groups of cancer survivors experienced a significantly increased risk of developing subsequent cancers, whereas men with prostate cancer presented a 31% lower risk. These differential risks provide clinicians with evidence-based suggestions for tailored surveillance and prevention strategies. .