Table_1_Development and Validation of Prognostic Nomogram for Primary Peritoneal Serous Carcinoma Compared With FIGO Staging System: A Population-Based Study.doc

BackgroundPrimary peritoneal serous carcinoma (PPSC) is a rare tumor that lacks a prognostic prediction model. Our study aims to develop a nomogram to predict overall survival (OS) of PPSC patients.
MethodsPatients confirmed to have PPSC between 2004 and 2012 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. LASSO and multivariate Cox regression analyses were used to screen for meaningful independent prognostic factors to construct a nomogram model for 3-, 5-, and 10-year OS among patients with PPSC. The nomogram compared the discrimination, calibration, and net benefits with the International Federation of Gynecology and Obstetrics (FIGO) staging system of PPSC patients.
ResultsEight variables were selected to establish the nomogram for PPSC. The established nomogram performed significantly better than the FIGO staging system (p < 0.05). The 3-, 5-, and 10-year OS of PPSC was 0.498, 0.306, and 0.152, respectively. Patients of old age, widowed marital status, grade high, FIGO IIIB, IIIC, or IV, lymph node metastasis, no lymphadenectomy, no surgery, and no chemotherapy got higher score which corresponds with higher risk and lower OS. In the multivariate Cox regression analysis, age, histological grade, FIGO staging, lymph node metastasis, and lymphadenectomy (four or more) were identified as independent prognostic factors for PPSC.
ConclusionsPPSC patients have distinct characteristics with respect to their presentation and survival outcomes. A prognostic nomogram constructed by various clinical indicators can provide better and more accurate predictions for patients with PPSC.

### 研究背景
原发性腹膜浆液性癌（Primary peritoneal serous carcinoma, PPSC）是一种罕见肿瘤，目前尚无成熟的预后预测模型。本研究旨在构建列线图（nomogram）以预测PPSC患者的总生存期（Overall Survival, OS）。

### 研究方法
本研究从监测、流行病学与最终结果（Surveillance, Epidemiology, and End Results, SEER）数据库中筛选出2004年至2012年间确诊为PPSC的患者。采用最小绝对收缩与选择算子（Least Absolute Shrinkage and Selection Operator, LASSO）回归及多因素Cox回归分析，筛选具有统计学意义的独立预后因素，以此构建用于预测PPSC患者3年、5年及10年总生存期的列线图模型。将该列线图的区分度、校准度及净获益，与PPSC患者的国际妇产科联盟（International Federation of Gynecology and Obstetrics, FIGO）分期系统进行对比。

### 研究结果
共筛选出8个变量用于构建PPSC患者的预后列线图。所构建的列线图性能显著优于FIGO分期系统（p < 0.05）。PPSC患者的3年、5年及10年总生存率分别为0.498、0.306和0.152。高龄、丧偶、高组织学分级、FIGO分期为IIIB、IIIC或IV期、存在淋巴结转移、未行淋巴结清扫术、未接受手术治疗及未接受化疗的患者得分更高，对应更高的风险与更差的总生存期。多因素Cox回归分析显示，年龄、组织学分级、FIGO分期、淋巴结转移及淋巴结清扫术（清扫淋巴结≥4枚）为PPSC的独立预后因素。

### 研究结论
PPSC患者的临床表现与生存结局具有显著异质性。基于多维度临床指标构建的预后列线图，可为PPSC患者提供更精准的预后预测。