Open AccessProgrammed Death Ligand-1 expression in stage II colon cancer - experiences from a nationwide populationbased cohort
Author(s) -
Ann Christina Eriksen,
Flemming Brandt Sørensen,
Jan Lindebjerg,
Henrik Hager,
René dePont Christensen,
Sanne Kjær-Frifeldt,
Torben Frøstrup Hansen
Publication year - 2019
Publication title -
bmc cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.358
H-Index - 129
ISSN - 1471-2407
DOI - 10.1186/s12885-019-5345-6
Subject(s) - microsatellite instability , medicine , oncology , cohort , immunohistochemistry , stage (stratigraphy) , colorectal cancer , malignancy , hazard ratio , population , surgical oncology , adjuvant therapy , proportional hazards model , cancer , pathology , allele , biology , confidence interval , paleontology , biochemistry , environmental health , microsatellite , gene
Background Patients suffering from high risk stage II colon cancer (CC) may benefit from adjuvant onco-therapy, but additional prognostic markers are needed for better treatment stratification. We investigated the prognostic value of Programmed Death Ligand-1 (PD-L1) in a true population-based cohort of patients with stage II CC. Methods PD-L1 expression on tumour cells was evaluated by immunohistochemistry in 572 colon cancers. Whole sections from tumour blocks representing the deepest invasive front of the primary tumour were used for analysis. A cut-off of 5% positivity was used for dichotomizing the data. The prognostic value was investigated in Cox proportional hazard models for recurrence-free survival (RFS) and overall survival (OS). Results Overall, 6% of the tumours were classified as high PD-L1. High PD-L1 was related to female gender ( p = 0.028), high malignancy grade (< 0.001), right side localization ( p < 0.001) and microsatellite instability (MSI) (p < 0.001). Thirty-one (18%) of the MSI and 4 (1%) of the microsatellite stable tumours were classified as high PD-L1, respectively. PD-L1 expression provided no prognostic value as a single marker. In patients with MSI tumours, high PD-L1 expression had no significant impact regarding OS or RFS. Conclusions PD-L1 expression in tumour cells of stage II CC did not provide any prognostic impact, neither in the entire population-based cohort nor in the group of MSI patients. Additional investigations of the immunogenic microenvironment are needed for evaluating the prognostic information in CC.