Bone metastases in endometrial cancer: Report on 19 patients and review of the medical literature

Objective Because few cases of bone metastases of endometrial cancer have been reported, and information is scarce on their incidence, treatment, prognosis, and outcomes, we sought to compile a series of bone metastases of endometrial cancer and to systematically review the medical literature. Methods We retrospectively reviewed medical records of patients who had osseous metastases of endometrial cancer treated initially at Mayo Clinic (1984-2001), and of all patients who were referred for treatment of primary bone metastases after primary treatment for endometrial cancer elsewhere. Results Of 1632 patients with endometrial cancer, 13 (0.8%) had primary bone dissemination and 6 (0.4%) were referred after initial treatment. Three (15.8%) of these 19 had bone metastases at presentation; in the rest, median time to recurrence was 19.5 months (range, 3-114). The most common sites were the spine and hip. Median survival after metastasis was 12 months (range, 2-267). Median survival after radiotherapy alone vs. multimodal treatment was 20 months (range, 12-119) vs. 33 months (range, 9-267), respectively (P >.99). Of the 87 cases we reviewed from the literature, all but 1 (98.9%) had diagnoses based on symptoms. Multiple bone involvement and extraosseous dissemination were associated with poor prognosis. Type II endometrial cancer (i.e., serous or clear-cell histology) was associated with shorter life expectancy after diagnosis of bone metastasis compared to Type I tumors. Conclusions The incidence of primary bone metastases of endometrial cancer is < 1%. Single bone metastases without extraosseous spread indicate less aggressive disease. Optimal treatment is unclear.