Clinical variables and outcomes
tumor, death, Tumor
TUMOR, METASTASES, TUMOR
The collected patient information included age, race, sex, histology, primary site, tumor number, tumor size, first malignant primary indicator, tumor grade, distant metastases, tumor stage, surgery, scope of regional lymph node surgery, regional nodes, surgical procedure of other sites, chemotherapy, and radiotherapy. Racial categories were classified as White and others (including Asian or Pacific Islander, American Indian/Alaska Native, Black, or Unknown). The primary site was determined in several locations including the adrenal gland, retroperitoneum, and others. The tumor stage was classified into four types based on SEER Combined Summary Stage: localized, regional, distant, and unknown/unstaged. Distant metastases occurred in organs such as the bone, brain, liver, and lung. The optimal cutoff value for tumor size was determined by the X-Tile software, and then categories as 0–62 mm, 63–87 mm, 88–989 mm, and unknown. Tumor grade was stratified as Grade I (well-differentiated), Grade II (moderately differentiated), Grade III (poorly differentiated), Grade IV (undifferentiated), or unknown. OS served as the primary endpoint, defined as the duration (in months) from the date of diagnosis to death or the last follow-up.