Characteristics and outcomes of patients with colorectal cancer and bone metastasis.

Abstract

e15063 Background: Bone metastasis from colorectal cancer is a relatively rare phenomenon. The aim of this study is to identify the risk factors and survival patterns of bone metastasis after colorectal cancer diagnosis. Methods: A total of 23,846 colorectal cancer patients who were diagnosed between 1972 and 2017 at Mayo Clinic were included in the analysis. Freedom from bone metastasis since diagnosis at 5, 10, 15, 25 and 35-years were estimated using Kaplan-Meier method. Multivariable Cox regression models were used to assess the differences in overall survival rate for patients with different cancer sides and cancer locations. All tests were two-sided with alpha level set at 0.05. Results: A total of 798 (3.3%) patients had a diagnosis of bone metastasis after colorectal cancer diagnosis over a median follow up of 3.2 years. Thirty-five year freedom from bone metastasis was 83% (95%CI: 80%-86%) for all patients, and were 87.13%, 82.29% and 77.26% for left colon, right colon and rectal cancer patients. Male gender, recent surgical years, and higher cancer stage were associated with higher risk of developing bone metastasis after colorectal cancer diagnosis. Rectal cancer patients had higher hazard of developing bone metastases compared to left and right colon cancer patients. Conclusions: We were able to identify several patient and tumor-related factors associated with the development of bone metastasis in patients with colorectal cancer. The proportion and factors identified are similar to other studies. Future directions would be to analyze other molecular determinants within this subset of patients.[Table: see text]