Materials and variables
death, tumor, cancer, serous, primary malignant tumor
CANCER, TUMOR, EPITHELIAL OVARIAN CANCER
Data for this research was acquired from the Surveillance, Epidemiology, and End Results (SEER) Program—SEER research plus data (consisting of 17 populations based on cancer registration from 2000 to 2019) by utilizing the SEER*Stat software (SEER*Stat version 8.4.0.1). The medical ethics review and informed consent were not needed in this research. Cases were collected in terms of the inclusion criteria and exclusion criteria as follows. The inclusion criteria including: (1) Malignant epithelial ovarian cancer (EOC) cases (primary site recode of C56.9; ICD-O-3 codes including: serous (8441–8442,8460–8463,9014), mucinous (8144,8434,8470–8472,8480–8482), endometrioid/adenocarcinoma (8380–8383, 8560, 8570), clear cell (8310, 8313/3,8443–8444,9110), and others containing transitional cell as well as epithelial-stroma (8020–8021,8120,8122,8130, 8810,8890,8950,9000)). (2) Age ≥ 60 at diagnosis in patients with EOC. (3) pathologically confirmed; (4) only one primary malignant tumor; (5) active follow-up. The exclusion criteria: (1) SEER cause-specific death unknown (2) SEER historic stage A or AJCC stage unknown; (3) survival months equal to zero or unknown; (4) surgery unknown; (5) grade unknown, tumor size unknown and regional nodes examined or positive unknown. The workflow of this research was shown in Fig. Flow diagram of the elderly epithelial ovarian cancer patients based on the inclusion and exclusion criteriaWe randomly divided all patients into training and validation groups by SPSS 20.0 at a ratio of 2:1. Nomogram was developed mainly based on the training set, while the evaluation and validation were performed by using the validation set. A total of twenty-two clinicopathological variables of EOC patients were extracted from the SEER database. The overall survival (OS) and cancer-specific survival (CSS) were considered endpoint times.