The bodies fight against cancer: is human leucocyte antigen (HLA) class 1 the key?

Abstract

Loss of human leucocyte antigen (HLA) class I expression has been implicated in tumour progression and metastasis; however, studies reporting its relationship with long-term survival are few in number with conflicting reports. The aim of this review was to assess the prognostic value of HLA class I expression in gastrointestinal cancer. Major electronic databases, including Medline, Embase, Cochrane Library and Pubmed were searched for original studies. Two independent reviewers assessed each study against inclusion and exclusion criteria. All data were specific to gastrointestinal cancer surgery. Fourteen original studies were included in this present review. In oesophageal cancer, reduced expression of HLA-A, HLA-B, HLA-C and HLA-G were associated with poorer survival. However, in gastric and colorectal cancer, the prognostic value of HLA-A, HLA-B, HLA-C and HLA-G remains conflicting. Antibody use and reporting methodology was different between all 14 studies examined. Variability in antibody use makes it difficult to validate HLA class I expression as an independent prognostic marker in GI cancer. Consensus guidelines, incorporating heavy and light chain antibodies, are required with further studies on HLA class I expression being performed to validate its prognostic value.