PD-1 blockade in neoadjuvant setting of DNA mismatch repair-deficient/microsatellite instability-high colorectal cancer

• Published in: Oncoimmunology Vol. 9; no. 1; p. 1711650
• Main Authors: Liu, Ding-Xin, Li, Dan-Dan, He, Wan, Ke, Chuan-Feng, Jiang, Wu, Tang, Jing-Hua, Kong, Ling-Heng, Li, Yuan, Sui, Qiao-Qi, Xiao, Bin-Yi, Li, Wei-Rong, Hong, Zhi-Gang, Xu, Rui-Hua, Pan, Zhi-Zhong, Zhang, Xiao-Shi, Ding, Pei-Rong
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01.01.2020; Taylor & Francis Group
• Subjects: Colorectal cancer; immune checkpoint blockade; microsatellite instability; neoadjuvant; Original Research; PD-1; microsatellite instability; neoadjuvant; PD-1; Colorectal cancer; immune checkpoint blockade
• ISSN: 2162-402X; 2162-4011; 2162-402X
• DOI: 10.1080/2162402X.2020.1711650

Background: Although PD-1 blockade has significantly improved the survival of metastatic colorectal cancer with DNA Mismatch Repair-Deficient/Microsatellite Instability-High (MSI-H), the data on neoadjuvant setting is limited. Methods: In this retrospective study, we enrolled eight patients with advanced MSI-H colorectal cancer from three hospitals. Four patients are locally advanced and four are metastatic. All the patients received at least two doses of PD-1 antibody with or without chemotherapy as neoadjuvant therapy. The aim of the present study was to evaluate the short-term efficacy and toxicities of this strategy. Results: All the enrolled eight patients had a major response in imaging and/or pathological evaluation. Five of the seven resected patients were evaluated as pathological complete response. One patient without surgery has a clinical complete response (cCR) tumor response. Conclusions: Neoadjuvant PD-1 blockade induced tumor regression with a major clinical and pathological response in advanced dMMR/MSI-H colorectal cancer. Further studies are required to evaluate the long-term effect of this strategy.