Clinical characteristics and prognostic factors analysis of patients stricken with double primary breast and ovarian cancer based on the SEER database.

BACKGROUND

Dual primary breast cancer (BC) and ovarian cancer (OC) represent a distinct subset of patients with diverse survival situation compared to those with a single primary BC or OC. Nonetheless, comprehensive research on their clinical characteristics and prognosis is lacking. This study conducted a retrospective analysis of clinical characteristics, survival outcomes, and prognostic factors of dual primary BC and OC patients.

METHODS

We applied the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database to identify patients with dual primary BC and primary OC (DPBOC) from 2000 to 2019, and divided patients into two groups: the BC-first group (BO group) and the OC-first group (OB group). Moreover, we employed Kaplan-Meier method to assess overall survival (OS), breast cancer-specific survival (BCSS), and ovarian cancer-specific survival (OCSS), and the Cox proportional hazards model to analyze prognostic factors.

RESULTS

There were 1,074 patients enrolled, 665 in the BO group and 409 in the OB group. The median time interval was for 48 (range, 0-228) months. There were significant differences in serous carcinoma and OC tumor stage between the two groups (P<0.001; P<0.001). There was no significant difference in BCSS between the two groups (Log-rank P=0.67), but the BO group had inferior OS and OCSS than the OB group (Log-rank P<0.001). Patients with an interval of ≥48 months had a significantly lower risk of death [hazard ratio (HR) =0.323, 95% confidence interval (CI): 0.264-0.395, P<0.001; HR =0.527, 95% CI: 0.305-0.908, P=0.02; HR =0.709, 95% CI: 0.560-0.897, P=0.004].

CONCLUSIONS

OC primarily determines the survival outcomes of DPBOC. Patients with BC as the first primary cancer (FPC) have a worse prognosis than patients with OC as FPC. After a diagnosis of BC or OC, we should pay close attention to another site, particularly after BC diagnosis, and monitor screening for ovarian lesions as early as feasible, as well as strengthening the treatment for OC.