Therapeutic approaches in patients with bone metastasis due to endometrial carcinoma - A systematic review.

Background: Bone metastases (BM) are uncommon in endometrial carcinoma (EC), without information on the optimal oncologic management of patients with BM in EC. Here, we systematically review clinical characteristics, treatment approaches and prognosis in patients with BM in EC. Methods: We conducted a systematic literature search until 27th March 2022 on PubMed, MEDLINE, Embase and clinicaltrials.gov. Outcomes included treatment frequency and survival after BM with comparators being treatment approaches (local cytoreductive bone surgery, systemic therapy, and local radiotherapy). Risk of bias was assessed using the NIH Quality Assessment Tool and Navigation Guide methodology. Results: We retrieved 1096 records of which 112 retrospective studies (12 cohort studies, 12/12 fair quality; 100 case studies, 100/100 low quality) with a total of 1566 patients were included. The majority had a primary diagnosis of FIGO stage IV, grade 3 endometrioid EC. Singular BM were present in a median of 39.2%, multiple BM in 60.8% and synchronous additional distant metastases in 48.1% of patients respectively. In patients with secondary BM median time to bone recurrence was 14 months. Median survival after BM was 12 months. Local cytoreductive bone surgery was assessed in 7/13 cohorts and performed in a median of 15.8% (interquartile range [IQR] 10.3-43.0) of patients. Chemotherapy was assessed in 11/13 cohorts and administered in a median of 55.5% (IQR 41.0-63.9), hormonal therapy (7/13 cohorts) in 24.7% (IQR 16.3-36.0), and osteooncologic therapy (4/13 cohorts) in 2.7% (IQR 0.0-7.5) of patients respectively. Local radiotherapy was assessed in 9/13 cohorts and performed in a median of 66.7% (IQR 55.6-70.0) of patients. Survival benefits were seen in 2/3 cohorts after local cytoreductive bone surgery, and in 2/7 cohorts after chemotherapy without survival benefits in the remaining cohorts and investigated therapies. Limitations include the lack of controlled intervention studies, the heterogeneity and retrospective nature of the investigated populations. Conclusions: This systematic review shows heterogenous therapeutic approaches in clinical practice without clear evidence for optimal oncologic management for patients with BM in EC.