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.