The programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) checkpoint pathway in the microenvironment of intrahepatic cholangiocarcinoma has prognostic significance, according to a new study published in the journal Cancer Immunology, Immunotherapy.

Moreover, the expression of PD-L1 on immune cells, in both resection and biopsy specimens, seems to be a strong independent predictor for a favorable outcome, according to the authors of the study.

The prognosis for cholangiocarcinoma depends on the location of the tumor and its resectability. Surgery is the only option for long-term survival but only a few patients are candidates, as the disease is usually diagnosed in its advanced cases. 

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In the present study, a team of researchers from Romania analyzed all cases of intrahepatic cholangiocarcinoma admitted to a tertiary healthcare facility over 10 years. The team retrieved the clinical information, laboratory values, imaging studies, and survival data from all cases and conducted immunostaining of PD-L1 on representative pathology slides for each case.

The researchers analyzed 136 samples. More than a third of these (38.97%) showed PD-L1 positivity on tumoral cells while 34.8% showed positivity on tumor-infiltrating immune cells, 10.11% did so on epithelial cells within the area around the tumor, and 15.95% did on immune cells from the area around the tumor.

The overall survival of patients who were PD-L1-positive in tumoral cells and tumor-infiltrating immune cells was significantly higher than the others.

However, only PD-L1 positivity on tumor-infiltrating immune cells was found to be a favorable factor for survival after adjusting for age, the number of tumors, size of tumors, and tumor differentiation.

The researchers also reported that a high immune cell count also correlated with better overall survival.

“Our study is the first to bring evidence that tumor-infiltrating immune cells PD-L1 expression on both resection and biopsy specimens might be a strong independent predictor for a favorable outcome in [intrahepatic cholangiocarcinoma],” they wrote.


Mocan LP, Craciun R, Grapa C, et al. PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor for patients with intrahepatic cholangiocarcinoma. Cancer Immunol Immunother. Published online October 17, 2022. doi:10.1007/s00262-022-03309-y