The Impact of a History of Different Other Cancers on the Long-Term Outcomes of Patients with Intrahepatic Cholangiocarcinoma: A Population-Based Analysis

BACKGROUND: The characteristics and outcomes of patients with intrahepatic cholangiocarcinoma (ICC) with prior malignancy are poorly clarified. This study is aimed at exploring the impact of prior malignancy on the long-term outcomes of ICC patients. METHODS: Using the Surveillance, Epidemiology, and End Results (SEER) program, ICC patients diagnosed between 2004 and 2018 were identified. Kaplan-Meier curves and Cox analysis were used to evaluate the impact of prior malignancy on the prognosis of ICC patients. RESULTS: A total of 9667 ICC patients were identified; among them, 782 (8.09%) had a history of prior cancer. Prostate, breast, colorectal, bladder, and liver/gallbladder/other biliary cancers were the most common types of prior cancer. Patients with prior cancer had better tumor-related profiles than those without prior cancer, namely, the former patients showed a lower proportion of positive AFP levels and vascular invasion, a lower AJCC stage, a smaller tumor size, and a lower stage of tumor grade. The median survival times after the diagnosis of ICC were 10 and 11.5 months for patients with and without prior cancer, respectively. Multivariate regression analysis suggested that prior cancer did not contribute to inferior overall survival (OS, HR 0.870, 95% CI 0.797-0.950, and p = 0.002) or cancer-specific survival (CSS, HR 0.820, 95% CI 0.741-0.906, and p < 0.001). CONCLUSIONS: A history of prior cancer does not lead to worse OS or CSS for ICC patients. The exclusion of patients with prior cancer from clinical trials should be reconsidered.