Published online Feb 15, 2020. doi: 10.4251/wjgo.v12.i2.173
Peer-review started: April 3, 2019
First decision: November 11, 2019
Revised: November 28, 2019
Accepted: December 13, 2019
Article in press: December 13, 2019
Published online: February 15, 2020
Processing time: 323 Days and 23 Hours
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal diseases, with an average 5-year survival rate of less than 10%. Unfortunately, the majority of patients have unresectable, locally advanced, or metastatic disease at the time of diagnosis. Moreover, traditional treatments such as chemotherapy, surgery, and radiation have not been shown to significantly improve survival. Recently, there has been a swift increase in cancer treatments that incorporate immunotherapy-based strategies to target all the stepwise events required for tumor initiation and progression. The results in melanoma, non-small-cell lung cancer and renal cell carcinoma are very encouraging. Unfortunately, the application of checkpoint inhibitors, including anti-CTLA4, anti-PD-1, and anti-PD-L1 antibodies, in pancreatic cancer has been disappointing. Many studies have revealed that the PDAC microenvironment supports tumor growth, promotes metastasis and consists of a physical barrier to drug delivery. Combination therapies hold great promise for enhancing immune responses to achieve a better therapeutic effect. In this review, we provide an outline of why pancreatic cancer is so lethal and of the treatment hurdles that exist. Particular emphasis is given to the role of the tumor microenvironment, and some of the latest and most promising studies on immunotherapy in PDAC are also presented.
Core tip: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal malignancies. Treatments such as surgery, radiation, and chemotherapy have limited efficacy due to the extensive heterogeneity of genetic mutations and the dense stromal environment, among other causes. In recent years, immunotherapy has been successfully applied in the treatment of various types of cancers, and immunotherapy combined with the above treatments could create more favorable conditions for the fight against PDAC.