3.1. Patient characteristics
cancer, tumor
BRAIN METASTASIS, TUMOR, LUNG METASTASIS, CANCER, BONE METASTASIS, LIVER METASTASIS
We extracted data from 2370 patients from the SEER database and randomly divided them into a training set (1659 patients) and validation set (711 patients) in a 7:3ratio. The median follow-up durations were 13 months and 10 months for the training and validation sets, respectively. Table Patients’ demographics and clinicopathological characteristics.AJCC = American joint committee on cancer.The characteristics of patients in the training set were similar to those in the validation set. Among them, 67.4% were males, 32.6% were females, and 50.7% were < = 60 years of age. 61 to 70 years old accounted for 26.5%, > = 71 years old accounted for 22.8%; bone metastasis accounted for 10.1%, brain metastasis accounted for 1.4%, liver metastasis accounted for 39.4%, lung metastasis accounted for 11.2%. Patients with tumor size < = 2.8 cm, 2.9 to 4.7 cm and > = 4.8 cm accounted for 15.9%,27.7%, and 56.4% of the included patients, respectively. With regard to treatment modality, radiotherapy was performed in 26.1% of patients and chemotherapy in 77.7% of patients. No significant differences were found between the training and validation sets for any variable included in this study.