Data source and data extraction
cancer, tumor, death
CANCER, TUMOR
Information on PC patients over 65 years old undergoing non-surgical treatment between 2010 and 2018 was extracted from the SEER database. The SEER database serves as a national cancer database registers data from 18 cancer medical centers, covering approximately 30% of the population. Since the data in the SEER database are publicly available and the patient information is hidden, ethical approval and patient informed consent are not required. We followed the research guideline book published in the SEER database for the study.The variables we obtained from the SEER database including age, race, marital status, year of diagnosis, tumor grade, TNM stage, radiotherapy method, chemotherapy, PSA, GS, and patient follow-up outcomes, including survival status, cause of death, and survival time. The race of the patients was classified as white, black, and other types. Inclusion criteria: (1) patients aged 65 years and older; (2) a pathological diagnosis of PC; and (3) patients receiving non-surgical treatment. Exclusion criteria: (1) patients younger than 65 years old; (2) unknown tumor grade; (3) unknown TNM stage; (4) patients undergoing surgical treatment or patients with unknown surgical treatment; (5) unknown GS; (6) PSA unknown; (7) survival time less than 1 month or survival time unknown. A flowchart of patient inclusion and exclusion is shown in Fig. Flowchart for inclusion and exclusion of elderly non-surgical treated PC patients.