Frequency, Morbidity, and Mortality of Bone Metastases in Advanced Hepatocellular Carcinoma

Background: Bone metastases are common in hepatocellular carcinoma (HCC), but their incidence, morbidity, and mortality are not well defined. Methods: The Memorial Sloan Kettering Cancer Center database was queried for all patients with HCC and metastases seen from 2002 to 2014. The prevalence of bone metastasis was determined and cumulative incidence function was used to estimate the probability of developing a bone metastasis. Regression models were created to identify risk factors for osseous metastasis. The frequency of skeletal-related events (SREs), defined as pathologic fracture, spinal cord compression, need for radiation therapy to bone, and/or surgical resection of bone, was determined and cumulative incidence function was used to estimate the probability of SRE development. Regression models were created to identify SRE risk factors. Correlation of clinicopathologic parameters, including bone metastases and SREs, with overall survival was analyzed using Kaplan-Meier methodology. Results: A total of 459 patients with HCC and extrahepatic metastases were identified; 151 patients (32.9%) had or developed bone metastases: 128 (27.9%) as a primary site and 23 (4.6%) as a secondary site of extrahepatic disease. Among the 331 patients without bone metastasis at presentation, the yearly incidence of bone metastasis was 6.4% (95% CI, 3.6%-9.2%). Hepatitis B virus (HBV) infection increased the chance of developing a bone metastasis (P=.02). The cumulative incidence of SREs was 50% at 6 months. Univariate analysis showed that patients with HBV-related HCC had a significantly higher incidence of SREs (P=.02). Sorafenib and bisphosphonates each protected against SREs. The presence of SREs was independently associated with a worse overall survival (hazard ratio, 2.13; 95% CI, 1.52-2.97; P<.01) in the multivariable model. Conclusions: Patients with AJCC stage IV HCC and bone metastases that are clinically evident on routine radiography or on clinical examination at presentation are apt to develop frequent, morbid, and mortal SREs, whereas those without evident bone metastasis at presentation are unlikely to develop these complications.