The prevalence, associated factors for bone metastases development and prognosis in newly diagnosed ovarian cancer: a large population based real-world study.

Background: Ovarian cancer (OC) is one of the most common malignancies in women. Advanced bone metastases (BM) commonly result in the poor prognosis. We aim to evaluate the prevalence and associated factors for the de novo BM development and prognosis in OC. Materials and methods: The present study was a cohort study that used the United States based National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. SEER documented OC patients, diagnosed between 2010 and 2015, were included in the present study. Univariable and multivariable logistic regression analyses were employed to identify associated factors for BM development. Kaplan-Meier analysis was used to estimate the overall survival and multivariable proportional hazard regression was used to identify the prognostic factors for OC patients with BM. Results: A total of 32,178 eligible OC patients were included in the present study, the prevalence of de novo BM was 1.09% (N=352). Non-serous histology [Odds Ratio (OR)=3.05; 95% CI: 1.63-5.72; P=0.001], T2/T1 stage (OR=3.39; 95% CI: 1.11-10.33; P=0.03), N1/N0 stage (OR=3.17; 95% CI: 1.72-5.84; P<0.001), and the presence of lung (OR=8.57; 95% CI: 4.37-16.80; P<0.001) and liver metastases (OR=4.95; 95% CI: 2.50-9.82; P<0.001) were all significantly associated with de novo BM development. Median survival for OC with BM was 5.00 (95% CI: 3.76-6.24) months. Multivariable Cox regression showed serous histology [Hazard ratio (HR)=1.44; 95% CI: 1.01-2.06; P=0.046] was positively associated with overall death, while surgery of the primary site (HR=0.42; 95% CI: 0.29-0.61; P<0.001) was negatively associated with overall death. Conclusion: Bone metastasis is rare in ovarian cancer patients. The factors associated with BM development and prognosis can be potentially used for BM early screening and individualized treatment.