Treatment and prognosis in colorectal cancer patients with bone metastasis

We have reviewed the cases of every patient presenting with bone metastasis after colorectal surgery and tried to establish the features of this clinical entity and generate basic strategies to the therapeutic management of this condition. Of 928 primary tumor resected colorectal cancer patients, 12 (1.3%) were identified with bone metastasis and included in this study. The majority of primary tumors were located at the rectosigmoid portion of the colon. All cases were highly advanced at the time of diagnosis, including 8 cases of stage IV by TNM classification. Sites of metastatic tumors were concentrated in lumber or pelvic bones. At the onset of bone metastasis, 9 of the 12 cases had other metastatic sites, i.e., only 3 patients had bone metastasis alone. Survival after onset of bone metastasis was very poor, with a median survival of approximately 5 months and a 20% survival rate at 1 year. With regard to cause of death, seven patients died of pulmonary failure, one of liver failure, and one of DIC. Only 2 cases of solitary osseous metastasis have survived more than 1 year. In order to significantly improve prognosis, the early detection of bone metastases is important.