Purpose: Colorectal cancer (CRC) is a common tumor of the digestive tract that tends to metastasize and leads to high mortality. Ocular metastases (OM) from colorectal cancer are being increasingly diagnosed, and they can lead to a poor prognosis. Serum lipids are a known risk factor for cardiovascular disease, and are also relevant to the occurrence of CRC. In this study, we examined the levels of serum lipids and tried to determine whether there were correlations with the occurrence of OM in patients with colorectal cancer, in order to determine whether serum lipid levels may be a risk factor for OM in this patient population.
Patients and methods: Records from a total of 703 patients treated for colorectal cancer from August 2005 to August 2017 were involved in this study. Student’s t -tests, nonparametric rank sum tests, and Chi-square tests were applied to describe whether there were significant differences between the OM group and non-ocular metastases (NOM) group. We used binary logistic regression analysis to determine the risk factors and receiver operating curve (ROC) analyses to assess the diagnostic value for OM in CRC patients.
Results: There were no significant differences in gender, age, histopathology type, or tumor classifications between the OM and NOM groups. The levels of serum TC, HDL, and LDL were significantly different between patients with and without lymph node metastases as well as male and female patients. The OM group had higher serum HDL levels compared to the NOM group. Binary logistic regression indicated that HDL was a risk factor for OM in colorectal cancer patients. The ROC curves showed that the AUC of HDL was 0.660. The cutoff value of HDL was 1.27 mmol/L, with a sensitivity of 0.619 and a specificity of 0.650. 
Conclusion: HDL levels are correlated with ocular metastases in colorectal cancer patients.
Keywords: high-density lipoprotein, ocular metastases, colorectal cancer, independent risk factor