Genomic analysis of advanced malignant soft tissue tumors to suggest effect of genome-wide loss-of-heterozygosity of germline mutations/variants on anti-PD-1 immunotherapy response and survival of the patients

Autor: Hajime Higuchi, Yuko Takahashi, Satoshi Teraoka, Yu Oyama, Junko Yotsumoto, Yoshihiro Komohara, Shinichi Toyooka, Jun Yashima, Shinsuke Aida, Yasuo Ono, Koichi Doi, Ken Suzawa, Hiroyuki Narahara, Hiromasa Yamamoto, Ayumi Saito, Yasutomo Miyaji, Hiroko Sano, Katsuhito Takahashi
Rok vydání: 2020
Předmět:
Zdroj: Journal of Clinical Oncology. 38:11531-11531
ISSN: 1527-7755
0732-183X
Popis: 11531 Background: Malignant soft tissue tumor is a rare cancer with few therapeutic options. Although recent genomic characterization of soft tissue sarcoma revealed massive CNA and an excess of polygenic burden of pathological germline variants, their clinical and therapeutic significance remains to be understood. Methods: We recruited 155 patients with malignant soft tissue tumors (135 female and 20 male, mean age 51, 100 LMS, 19 LPS, 4 ESS, 3 UPS, 3 AS, 3 MPT, 3 GIST and others) of confirmed metastasis/recurrence. Whole exome sequencing was performed as reported in 2018ASCO. The MSI status was analyzed by PCR. Tumor immune microenvironment was assessed by immunohistochemistry. Results: Of the 595 COSMIC genes, heterozygous germline mutations/variants of the genome-wide 0-44 genes (av. 9.7/tumor) showed somatic loss-of-heterozygosity (LOH) with allele frequency of more than 70%. Patients with less than 33% LOH (n=53) in the total of somatic and LOH mutations showed improved 5-year survival rate compared with those (n=102) with more LOH (71% vs 52%, p=0.037). LMS (n=100) had higher value of LOH mutations than other tumors (n=55)(av. 55.5 vs 31.2%, p2). Case 2 had no LOH mutations while case 1 had 37% LOH with more total mutations in tumor (16.1 vs 85.9/Mb). Higher values of LOH (av. 67 vs 19%) were clearly correlated with decreased density of CD8+TIL in tumor tissues (av. 9.6 vs 429/mm2, n=5, p=0.018). Conclusions: Our results, for the first time, suggest that in malignant soft tissue tumors, accumulation of genome-wide LOH of germline mutations/variants, from which self-antigens could be generated, may influence tumor immune microenvironment, and thus influence immunotherapy response and survival of the patients.
Databáze: OpenAIRE
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