Human leukocyte antigen (HLA) expression appears to be tied to clinical outcomes in penile cancer, according to a study published in The Journal of Urology.
Rosa S. Djajadiningrat, M.D., from the Netherlands Cancer Institute in Amsterdam, and colleagues constructed tissue microarrays from penile cancer tissue blocks from 168 patients who underwent surgical resection between 2000 and 2009.
HLA expression was determined using immunohistochemical staining (using classic and nonclassic molecules), and expression was scored semiquantitatively.
The researchers found that complete and partial loss of total classic HLA class I were seen in 32 and 50 percent of cases, respectively. Up-regulation of HLA-E and G was seen in 16 and 13 percent, respectively.
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Partial HLA-A loss was significantly associated with decreased survival overall (hazard ratio, 2.3) and in human papillomavirus-negative patients alone (hazard ratio, 3.4), when adjusting for relevant clinical parameters. Survival was not tied to abnormal HLA-B/C, E, or G expression levels.
“Complete understanding of the mechanisms and relevance of HLA down-regulation and immune evasion in regard to the clinical outcome will contribute to the future design of immunotherapy interventions,” the authors write.