Bone metastasis from gastric cancer: the incidence, clinicopathological features, and influence on survival

To evaluate the incidence, clinicopathological characteristics, treatment outcomes, prognostic factors, and survival of gastric cancer patients with bone metastases.

Of 4,617 gastric cancer patients who were treated between 2001 and 2013, 176 patients with bone metastases were analyzed.

The incidence of bone metastasis was 3.8%. The most common histopathological subtype was adenocarcinoma (79%) with poor differentiation (60.8%). The median interval from the diagnosis to bone metastasis was 11 months. The median survival time after bone metastasis was 5.4 months. Factors that were associated with longer median survival times included the following: isolated bone metastasis (P=0.004), well-differentiated tumors (P=0.002), palliative chemotherapy (P=0.003), zoledronic acid treatment (P<0.001), no smoking history (P=0.007), and no metastatic gastric cancer at the time of diagnosis (P=0.01). On the other hand, high levels of lactate dehydrogenase (LDH) (hazard ratio [HR]: 1.86; P=0.015), carcinoembryonic antigen (CEA) (HR: 2.04; P=0.002), and carbohydrate antigen (CA) 19-9 (HR: 2.94; P<0.001) were associated with shorter survival times. In multivariate analysis, receiving zoledronic acid (P<0.001) and performance status (P=0.013) were independent prognostic factors.

Smoking history, poor performance status, poorly differentiated adenocarcinoma, and high levels of LDH, CEA, and CA 19-9 were shown to be poor prognostic factors, while receiving chemotherapy and zoledronic acid were associated with prolonged survival in gastric cancer patients with bone metastases.