Patient Enrollment and Data Collection
tumor, Tumor, cancer, malignancy, tumors, upper GI tract
TUMOR, TUMOR, CANCER, PRIMARY TUMOR, TUMORS
All data of patients with PGIM were retrieved and collected from the SEER database, 18 Registries (with plus data, 2000-2018, Nov 2020 Sub; Data of baseline information, tumor characteristics, therapy provided, and follow-up data were collected. Baseline information included age (20-40 years, 41-64 years, >64 years), gender (female, male), marital status [married, others (unmarried, widowed, single, etc.)], race (White, Black, and others), previous cancer history (no, yes). Tumor characteristics included site [upper GI tract (esophagus, stomach), intestine, anorectum], tumor size (≤3 cm, 3-5 cm, ≥5 cm), and SEER stage (localized, regional, distant). A localized cancer is defined as a malignancy limited to the site of origin. A regional cancer is defined as direct tumor extension beyond the limits of the site of origin and/or regional lymph nodes involved. Distant tumors are tumor cells that have broken away from the primary tumor, have travelled to other parts of the body, and have begun to grow at a new location. Therapy provided was grouped into 4 groups: none, surgery only, radiation/chemotherapy only, and surgery combined with radiation/chemotherapy. Follow-up data included CSS and survival time (month). The unit of follow-up time was month. For patients with more than zero days of survival but did not reach 1 month, the survival time was recorded as 0.5 month to differentiate them from those who had zero day of survival.As the SEER database is available to the public, approval from a local ethics committee is not necessary.