Lung Metastases in Patients with Stage IV Pancreatic Cancer: Prevalence, Risk Factors, and Survival Impact

The aim of this study was to evaluate the prevalence, the clinicopathological variables associated with probability of lung metastases, and the impact of lung metastases on survival outcome in patients with stage IV pancreatic cancer (PC) treated with palliative chemotherapy. A total of 654 patients with stage IV PC who underwent palliative chemotherapy from 2010–2016 were retrospectively enrolled in this study. Possible clinical variables associated with lung metastases and survival outcome were examined by univariate and multivariate analysis. Lung metastases were detected in 15.0% (3.4% with isolated lung metastases and 11.6% with synchronic metastases to lung and other organs). Female gender, poorly differentiated tumor grade, and large primary tumor size were independent risk factor in multivariate analysis. The median overall survival (OS) time was 6.5 months in the entire cohort, while the median OS was 11.8, 6.9, 7.7, 10.1, and 5.0 months for patients with isolated lung, isolated liver, isolated peritoneum, isolated distant lymph nodes, and multiple sites metastases, respectively. Isolated lung metastases were a better prognosticator for OS in univariate and multivariate analysis. This study utilized real-world clinical practice data to assess the prevalence, risk factors, and survival impact of lung metastases in patients with stage IV pancreatic cancer.