RT Journal Article
SR Electronic
T1 Neoantigen load and HLA-class I expression identify a subgroup of tumors with a T-cell-inflamed phenotype and favorable prognosis in homologous recombination-proficient high-grade serous ovarian carcinoma
JF Journal for ImmunoTherapy of Cancer
JO J Immunother Cancer
FD BMJ Publishing Group Ltd
SP e000375
DO 10.1136/jitc-2019-000375
VO 8
IS 1
A1 Hirokazu Matsushita
A1 Kosei Hasegawa
A1 Katsutoshi Oda
A1 Shogo Yamamoto
A1 Kayo Asada
A1 Takahiro Karasaki
A1 Akira Yabuno
A1 Akira Nishijima
A1 Takahide Nejo
A1 Yukari Kobayashi
A1 Sho Sato
A1 Yuji Ikeda
A1 Manami Miyai
A1 Yusuke Takahashi
A1 Rui Yamaguchi
A1 Keiichi Fujiwara
A1 Hiroyuki Aburatani
A1 Kazuhiro Kakimi
YR 2020
UL http://jitc.bmj.com/content/8/1/e000375.abstract
AB Background There is increasing evidence for the benefit of poly ADP ribose polymerase (PARP) inhibitors in a subset of high-grade serous ovarian carcinoma (HGSC) patients, especially those with homologous recombination (HR)-deficient tumors. However, new treatment strategies, such as immune checkpoint inhibition, are required for patients with HR-proficient tumors.Methods A total of 80 cases of HGSC were analyzed in this study. Whole exome and RNA sequencing was performed for these tumors. Methylation arrays were also carried out to examine BRCA1 and RAD51C promoter methylation status. Mutations, neoantigen load, antigen presentation machinery, and local immune profile were investigated, and the relationships of these factors with clinical outcome were also analyzed.Results As expected, the numbers of predicted neoAgs were lower in HR-proficient (n=46) than HR-deficient tumors (n=34). However, 40% of the patients with HR-proficient tumors still had higher than median numbers of neoAgs and better survival than patients with lower numbers of neoAgs. Incorporation of human leukocyte antigen (HLA)-class I expression status into the survival analysis revealed that patients with both high neoAg numbers and high HLA-class I expression (neoAghiHLAhi) had the best progression-free survival (PFS) in HR-proficient HGSC (p=0.0087). Gene set enrichment analysis demonstrated that the genes for effector memory CD8 T cells, TH1 T cells, the interferon-γ response, and other immune-related genes, were enriched in these patients. Interestingly, this subset of patients also had better PFS (p=0.0015) and a more T-cell-inflamed tumor phenotype than patients with the same phenotype (neoAghiHLAhi) in HR-deficient HGSC.Conclusions Our results suggest that immune checkpoint inhibitors might be an alternative to explore in HR-proficient cases which currently do not benefit from PARP inhibition.