Gastric cancer with initial bone metastasis: a distinct group of diseases with poor prognosis

Bone metastasis (BM) is reported as a poor prognostic factor in gastric cancer. However, the clinicopathologic characteristics and clinical outcomes of patients with BM compared with patients without BM have not been well described.

The medical records of all metastatic or recurrent gastric cancer (MRGC) patients who visited our institution were reviewed. A total of 137 evaluable patients with BM were analysed together with historical control without BM (N=111).

Of 1342 MRGC patients, 141 (10.5%) had BM. Patients with BM could be divided into initial BM (BM present at initial diagnosis of MRGC; N=90) and late BM (N=47) groups. The median survival after the diagnosis of BM in all patients was 4.4 months (95% confidence interval [CI] 3.69-5.11). However, overall survival after the diagnosis of MRGC was significantly shorter in the initial BM group (5.0 versus 12.2 months, p<0.001). Compared with historical controls, patients with initial BM showed distinct clinicopathologic characteristics. Independent predictors of initial BM were a younger age, signet ring cell histology, primary tumour involving ⩾two-thirds of the stomach, pleural metastasis, thrombocytopenia and elevated alkaline phosphatase. According to a Cox proportional hazard model including both patients with BM and historical controls, initial BM, poor performance status, peritoneal metastasis, hypercalcemia and high carcinoembryonic antigen (CEA) were identified as poor prognostic factors, whereas chemotherapy was identified as a favourable factor (hazard ratio [HR] 0.33, 95% CI 0.22-0.49).

MRGC with initial BM is a distinct group of diseases with specific clinicopathologic characteristics and poor prognosis. Chemotherapy may improve survival in these patients.