Prognostic Factors of Bone Metastases from Colorectal Cancer in the Era of Targeted Therapy.

Various prognostic factors have been reported for bone metastases from different primary tumor sites. However, bone metastases from colorectal cancer are very rare, and the prognostic factors have not been investigated in detail.To identify prognostic factors of bone metastases from colorectal cancer.Retrospective cohort study using data from a prospectively collected database.A single tertiary care cancer center in Japan.Patients who developed bone metastases from colorectal cancer during the study period among all patients who received initial treatment for colorectal cancer at our hospital between 2005 and 2016 (n = 4538) were targeted.Overall survival after diagnosis of bone metastases from colorectal cancer.Ninety-four patients developed bone metastases, accounting for 2.0% of all patients with colorectal cancer who started treatment during the study period. The 5-year overall survival rate was 11.0%. Multivariable analysis identified the following independent risk factors associated with poor prognosis: age ≥70 years at diagnosis of bone metastases (hazard ratio 2.48, 95% CI 1.24-4.95, p < 0.01), curative surgery not performed as initial treatment (hazard ratio 2.54, 95% confidence interval 1.24-5.19, p = 0.01), multiple bone metastases (hazard ratio 2.44, 95% CI 1.30-4.57, p < 0.01), albumin level <3.7 g/dL (hazard ratio 3.80, 95% CI 1.95-7.39, p < 0.01), carcinoembryonic antigen ≥30 ng/mL (hazard ratio 1.94, 95% confidence interval 1.09-3.46, p = 0.02), and <3 chemotherapy options remaining at diagnosis of bone metastases (hazard ratio 2.83, 95% CI 1.51-5.30, p < 0.01). The median survival times for patients with 0-2, 3, and 4-6 risk factors were 25.0, 8.8, and 4.3 months, respectively.Single-center, retrospective design.Our results may facilitate multidisciplinary decision-making in patients with bone metastases from colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B930.