胰腺粘液腺癌（PSRCC）是一种罕见且侵袭性强的癌症，主要以病例报告的形式报道。由于缺乏大规模流行病学和预后分析，PSRCC患者的预后因缺乏公认的一线治疗策略而存在很大差异。本研究旨在比较PSRCC和胰管细胞癌（PDAC），即胰腺癌最常见的亚型之间的临床特征、治疗和预后，并建立这些亚型的预测模型。通过Surveillance, Epidemiology, and End Results（SEER）数据库获取1998年至2018年的PSRCC和PDAC患者的数据。然后，通过倾向性评分匹配（PSM），Kaplan-Meier生存曲线，Cox风险回归分析和最小绝对收缩和选择运算符（LASSO）分析，评估这两组的临床、人口统计和治疗特征，以及这两组之间的差异和影响因素。随后，通过KM和ROC分析构建和验证预后模型。最后，根据这些分析结果构建一张图表，用于预测PSRCC和PDAC患者的生存结果。本研究纳入了共计84,789名患者（432例PSRCC患者和84357例PDAC患者）。研究结果显示，与PDAC患者相比，PSRCC患者更有可能为男性，年龄在58-72岁之间，肿瘤体积更大，并且较少接受化疗。倾向性评分匹配前，PSRCC组的总体生存和癌症特异性生存率显著低于PDAC组，但在倾向性评分匹配后，两组的预后没有差异。另外，淋巴结比例（LNR），阳性淋巴结的对数几率（LODDS），肿瘤大小，年龄，T分期，婚姻状况和总体分期被发现是PSRCC的独立预后因素。最后，基于这些预后因素的预测模型和图表，可以准确预测SEER数据库和外部验证数据集中患者的生存率。在相同条件下，PSRCC和PDAC患者的预后相似；然而，PSRCC患者可能更难获得更好的治疗，从而导致他们的预后较差。版权所有 © 2023 周、李、黄、王、邹、熊、刘、文和张。

Pancreatic signet ring cell carcinoma (PSRCC) is a rare and aggressive cancer that has been reported primarily as case reports. Due to limited large-scale epidemiological and prognostic analyses, the outcomes of PSRCC patients varies greatly in the absence of recognized first-line treatment strategies. This study aimed to compare the clinical features, treatment, and prognosis of PSRCC and pancreatic ductal cell carcinoma (PDAC), the most common subtype of pancreatic cancer, and to establish predictive models for these subtypes.The data on PSRCC and PDAC patients from 1998 to 2018 was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Thereafter, the clinical, demographic, and treatment characteristics of the two groups and the differences and influencing factors of the two groups were evaluated by propensity score matching (PSM), Kaplan-Meier survival curves, Cox risk regression analyses, and least absolute shrinkage and selection operator (LASSO) analysis. Next, prognosis models were constructed and validated by KM and ROC analysis. Finally, a nomogram was constructed, based on the results of these analyses, to predict survival outcomes of PSRCC and PDAC patients.A total of 84,789 patients (432 PSRCC and 84357 PDAC patients) were included in this study. The results of the study revealed that, compared to the PDAC patients, PSRCC patients were more likely to be male, aged between 58-72 years, have larger tumor masses, and less likely to undergo chemotherapy. Before PSM, the overall survival and cancer-specific survival of the PSRCC group were significantly lower than those PDAC group, but there was no difference in the prognosis of the two groups after PSM. Additionally, lymph node ratio (LNR), log odds of positive lymph node (LODDS), tumor size, age, T-stage, marital status, and summary stage were found to be independent prognostic factors for PSRCC. Lastly, the prediction model and nomogram based on these prognostic factors could accurately predict the survival rate of the patients in SEER datasets and external validation datasets.The prognosis of PSRCC and PDAC patients is similar under the same conditions; however, PSRCC patients may have more difficulty in receiving better treatment, thus resulting in their poor prognosis.Copyright © 2023 Zhou, Li, Huang, Wang, Zou, Xiong, Liu, Wen and Zhang.