Survival and Causes of Death among Patients with Intrahepatic Cholangiocarcinoma in the United States from 2000 to 2018.

Background: Intrahepatic cholangiocarcinoma (iCCA) has shown a substantial increase in mortality globally. On the contrary, perihilar cholangiocarcinoma and distal cholangiocarcinoma have been decreasing. We aim to evaluate the causes of death after iCCA diagnosis.

Methods: We studied 8,962 patients with iCCA diagnosed between 2000 and 2018 in the United States. The standardized mortality ratio for each cause of death was calculated. We used R software version 3.5 to perform Kaplan-Meier survival tests and covariate-adjusted Cox models.

Results: Of the 8,962 patients diagnosed with iCCA, 7,335 (81.8%) died during the follow-up period with a mean age of death of 67.88 years. The highest number of deaths (4,786; 65.2%) occurred within the first year following iCCA diagnosis. 4,832 (66%) were from iCCA, 2,063 (28%) were from other cancers, and 440 (6%) were from non-cancer causes mainly cardiovascular disease. The overall mean survival after 1 year of diagnosis was 40.8% (39.8-41.9); however, the overall mean survival was 9.8% (9-10.5) after 5 years of diagnosis. The multivariable analysis showed that age, sex, stage, and management of iCCA have a statistically significant impact on survival.

Conclusions: Following iCCA diagnosis, about 34% died from non-iCCA causes. The most common non-iCCA cancer cause was liver cancer, and cardiovascular disease represents a substantial percentage of non-cancer deaths. Our findings provide insights into how iCCA survivors should be followed up regarding future risks.

Impact: The management and follow-up should be tailored to the needs of each patient with iCCA.