LAUSR

BACKGROUND Immune checkpoint inhibitors (ICIs), specifically programmed cell death receptor-1/ligand 1 (PD-1/L1) inhibitors, have shown potential pharmacological efficacy in several cancers. Nonetheless, data pertinent to their therapeutic efficacy in alveolar soft-part sarcoma (ASPS) are limited. OBJECTIVE The retrospective aspects of ICIs (anti-PD1/PD-L1 blockers) to target ASPS comparatively analyzed for clinical outcomes with other targeted immunotherapy modalities. METHODS We have conducted a systematic review without statistical analysis or comprehensive meta-analysis by collecting the articles published between 1952 and Sep 10th, 2020 by searching the following words: alveolar soft part sarcoma and immunotherapy including immune checkpoint, immune checkpoint inhibitors, and PD-1, PD-L1. We performed a pooled analysis of case reports, conferences, clinical trials, and other research reports pertinent to the efficacy of a PD-1 or PD-L1 antagonist in patients diagnosed with metastatic ASPS. RESULTS The effective studies include 10 case reports, 2 conference reports, 5 clinical trials, and 2 additional research reports. Total 110 patients were reported to be enrolled in the pooled analysis; among them, 87 (78.38%) received a PD-1/PD-L1 antagonist. Patients who received anti-PD-1/PD-L1as monotherapy, then their clinical response rates (CRR) were 63.22% whereas the patients who received targeted therapy and immunotherapy, their CRR was 78.95% (15/19). The patients treated with double immunotherapy, their CRR was 100% (4/4). Tumor mutational burden and mismatch repair status have significant implications to predict the prognosis of ASPS. CONCLUSION Alveolar soft-part sarcoma patients with distant metastases can exhibit better clinical outcomes with immunotherapy, particularly toripalimab, atezolizumab, and axitinib combinatorial regimen with pembrolizumab. In addition, this review describes the therapeutic implications to guide personalized medicine depending on the expression patterns of PD-1/PD-L1 during the immunotherapy with ASPS.