Background: Pancreatic ductal adenocarcinoma (PDAC) is a type of lethal gastrointestinal malignancy. It is mainly discovered at, and diagnosed with, an advanced stage of metastasis. As the only potentially curative treatment for PDAC, surgical resection has an uncertain impact on the survival of these patients. As such, we aimed to investigate if patients with metastatic PDAC (mPDAC) benefit from surgery. Methods: Patients with pancreatic cancer in 18 registries of the Surveillance, Epidemiology, and End Results database between 2000 and 2018 were reviewed retrospectively. According to the American Joint Committee on Cancer (AJCC), the eighth edition staging system was utilized. Propensity score matching was applied to strengthen the comparability of the study. The impact of surgery on survival was evaluated by restricted mean survival time (RMST) and Kaplan–Meier analysis. Results: A total of 210 well-matched mPDAC patients were included in the study. The 1 year, 3 year, and 5 year overall survival (OS) of patients undergoing surgery was 34.3%, 15.2%, and 11.0%, respectively. The 1 year, 3 year, and 5 year cancer-specific survival (CSS) of these patients was 36.1%, 19.7%, and 14.2%, respectively. RMST analysis revealed that mPDAC patients with surgery had better OS and CSS than those without (OS: 9.49 months vs. 6.45 months, p < 0.01; CSS: 9.76 months vs. 6.54 months, p < 0.01). Nevertheless, subgroup analysis demonstrated that such statistical significance especially existed in oligometastatic PDAC patients, which refers to those metastases that were limited in number and concentrated to a single organ in this study. Additionally, surgery was identified as a significant predictor for the long-term prognosis of patients (OS: [HR, hazard ratio] = 0.48, 95% CI: 0.36–0.65, p < 0.001; CSS: HR = 0.45, 95% CI: 0.33–0.63, p < 0.001). Lastly, a nomogram was established to predict whether an individual was suitable for surgical treatment in this study. Conclusions: Surgical resection significantly prolonged the long-term prognosis of oligometastatic PDAC patients. Such insights might broaden the management of patients with mPDAC to a large extent. However, a prospective clinical trial should be conducted before a recommendation of surgery in these patients.

Background: Serum lipids (SLs), the prominent indicators of lipid metabolism, produce an intricate impact on proliferation, invasion, and metastasis of cancer cells. However, the effects of serum lipids on the prognosis of ampullary adenocarcinoma (AC) have not been investigated. Methods: Patients with AC in the National Cancer Center of China between January 1998 and December 2020 were retrospectively reviewed. Survival analysis for overall survival (OS, Time from operation to death) and recurrence-free survival (RFS, Time from operation to first-time recurrence) was performed using Kaplan–Meier analysis and Cox proportional hazards models. Results: A total of 232 AC patients were enrolled into the study. SLs levels were significantly lower in patients with vascular invasion compared to those without (all p < 0.05). The 1-year, 3-year, and 5-year OS rates for AC patients were 86.1%, 64.1%, and 47.6% and 75.8%, 54.8%, and 46.5% for RFS. Biliary/pancreatic fistula (31.9%) and chemotherapy (81.4%) were the majority of postoperative complications and adjuvant therapy, respectively. According to Cox analysis, preoperative LDL-C was an independent prognostic factor for RFS (HR = 0.43, 95% CI: 0.21–0.85, p = 0.015), whereas no statistical significance existed in the analysis of HDL-C, TC, and TG. Conclusions: High levels of preoperative LDL-C is a significant predictor of prolonged prognosis in AC patients, which was also observed to be a protective factor to reduce vascular invasion.