High PD-L1 expression indicates poor prognosis of HIV-infected patients with non-small cell lung cancer.

BACKGROUND: The status of antitumor immunity represented by the expression of programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) and immune cell (IC) infiltration is unknown in HIV-infected patients with non-small cell lung cancer (NSCLC).

METHODS: Fifteen HIV-infected patients with NSCLC were compared with 29 non-HIV-infected patients with NSCLC. Analysis of 13 propensity-score-matched patients in the two groups was also compared. The expression of PD-1/PD-L1 and tumor infiltration by CD4+ , CD8+ , and CD56+ immune cells were examined by immunohistochemistry; score of ≥ 2 was defined as positive.

RESULTS: Although high PD-L1 expression in tumor cells was observed in HIV and non-HIV cohorts, the association of PD-1/PD-L1 was significant only in the HIV cohort. In overall as well as the propensity-matched analyses, HIV-infected patients with high PD-L1 expression showed shorter survival than HIV-infected patients with low PD-L1 expression; no significant difference was observed in this respect in the non-HIV cohort.

CONCLUSION: High PD-L1 expression in tumor tissue was associated with poor prognosis in HIV-infected NSCLC patients but not in non-HIV-infected NSCLC patients. These results suggest that antitumor immunity by PD-1/PD-L1 axis might be suppressed more in HIV-infected NSCLC patients as compared to their non-HIV-infected counterparts.