Risk for second primary ovarian cancer: a large population based on Surveillance, Epidemiology, and End Results database.

Objective: This study aims to evaluate the likelihood of developing a second primary ovarian cancer (OC) considering factors including age, race, and the types of initial malignancies encountered.

Methods: This study employed a retrospective cohort approach, compiling data on individuals diagnosed with OC from the Surveillance, Epidemiology, and End Results (SEER) program databases spanning the years 1975 to 2019. The analysis used standardized incidence ratios (SIR) with 95% confidence intervals (CI) to determine the likelihood of developing OC. The result was further refined by categorizing the data based on patient age, race background, first primary cancer types, the time elapsed since the second primary cancer diagnosis, and radiotherapy treatment.

Results: A total of 1,536,151 patients with second primary cancer being OC were included. The SIR of the second primary OC was observed to be elevated among patients between the ages of 18 to 64 years (SIR: 1.09, 95% CI: 1.06-1.13). In contrast, for patients who were 65 years of age or older, the SIR for a second primary OC was found to be relatively lower (SIR: 0.87, 95% CI: 0.83-0.91). A lowering, however not statistically significant, of the SIR of the second primary OC in patients with white race was presented. Within 2 months to 1-year diagnosis interval, the SIR of the second primary OC was highest (SIR: 1.48, 95% CI: 1.37-1.61). Liver, gallbladder, intrahepatic, and other bile ducts (SIR: 2.00, 95% CI: 1.38-2.81), and breast cancer (SIR: 1.20, 95% CI: 1.15-1.25) had higher SIRs of second primary OC.

Conclusion: This study identifies age, ethnicity, the time span between the diagnoses, and the types of initial cancers as factors correlated with the occurrence of a second primary OC. Our findings suggest that targeted surveillance should be considered for high-risk groups.