Dataset Information

Association of BRCA1- and BRCA2-deficiency with mutation burden, expression of PD-L1/PD-1, immune infiltrates, and T cell-inflamed signature in breast cancer.

ABSTRACT: Immune checkpoint inhibitors have demonstrated effective anti-tumour response in cancer types with high mutation burden (e.g. melanoma) and in subset of cancers with features of genomic instability (e.g. mismatch-repair deficiency). One possible explanation for this effect is the increased expression of immune checkpoint molecules and pre-existing adaptive immune response in these cancers. Given that BRCA1 and BRCA2 are integral in maintaining genomic integrity, we hypothesise that the inactivation of these genes may give rise to breast cancers with such immunogenic phenotype. Therefore, using two large series of publicly available breast cancer datasets, namely that from The Cancer Genome Atlas and Wellcome Trust Institute, we sought to investigate the association between BRCA1- and BRCA2-deficiency with features of genomic instability, expression of PD-L1 and PD-1, landscape of inferred tumour-infiltrating immune cells, and T-cell inflamed signature in breast cancers. Here, we report that BRCA1 and BRCA2-deficient breast cancers were associated with features of genomic instability including increased mutation burden. Interestingly, BRCA1-, but not BRCA2-, deficient breast cancers were associated with increased expression of PD-L1 and PD-1, higher abundance of tumour-infiltrating immune cells, and enrichment of T cell-inflamed signature. The differences in immunophenotype between BRCA1- and BRCA2-deficient breast cancers can be attributed, in part, to PTEN gene mutation. Therefore, features of genomic instability such as that mediated by BRCA1- and BRCA2- deficiency in breast cancer were necessary, but not always sufficient, for yielding T cell-inflamed tumour microenvironment, and by extension, predicting clinical benefit from immunotherapy.

SUBMITTER: Wen WX

PROVIDER: S-EPMC6483182 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Association of BRCA1- and BRCA2-deficiency with mutation burden, expression of PD-L1/PD-1, immune infiltrates, and T cell-inflamed signature in breast cancer.

Wen Wei Xiong WX Leong Chee-Onn CO

PloS one 20190425 4

Immune checkpoint inhibitors have demonstrated effective anti-tumour response in cancer types with high mutation burden (e.g. melanoma) and in subset of cancers with features of genomic instability (e.g. mismatch-repair deficiency). One possible explanation for this effect is the increased expression of immune checkpoint molecules and pre-existing adaptive immune response in these cancers. Given that BRCA1 and BRCA2 are integral in maintaining genomic integrity, we hypothesise that the inactivat ...[more]

PMID: 31022191

Similar Datasets

Project description:BACKGROUND: Increased number of single nucleotide substitutions is seen in breast and ovarian cancer genomes carrying disease-associated mutations in BRCA1 or BRCA2. The significance of these genome-wide mutations is unknown. We hypothesize genome-wide mutation burden mirrors deficiencies in DNA repair and is associated with treatment outcome in ovarian cancer. METHODS AND RESULTS: The total number of synonymous and non-synonymous exome mutations (Nmut), and the presence of germline or somatic mutation in BRCA1 or BRCA2 (mBRCA) were extracted from whole-exome sequences of high-grade serous ovarian cancers from The Cancer Genome Atlas (TCGA). Cox regression and Kaplan-Meier methods were used to correlate Nmut with chemotherapy response and outcome. Higher Nmut correlated with a better response to chemotherapy after surgery. In patients with mBRCA-associated cancer, low Nmut was associated with shorter progression-free survival (PFS) and overall survival (OS), independent of other prognostic factors in multivariate analysis. Patients with mBRCA-associated cancers and a high Nmut had remarkably favorable PFS and OS. The association with survival was similar in cancers with either BRCA1 or BRCA2 mutations. In cancers with wild-type BRCA, tumor Nmut was associated with treatment response in patients with no residual disease after surgery. CONCLUSIONS: Tumor Nmut was associated with treatment response and with both PFS and OS in patients with high-grade serous ovarian cancer carrying BRCA1 or BRCA2 mutations. In the TCGA cohort, low Nmut predicted resistance to chemotherapy, and for shorter PFS and OS, while high Nmut forecasts a remarkably favorable outcome in mBRCA-associated ovarian cancer. Our observations suggest that the total mutation burden coupled with BRCA1 or BRCA2 mutations in ovarian cancer is a genomic marker of prognosis and predictor of treatment response. This marker may reflect the degree of deficiency in BRCA-mediated pathways, or the extent of compensation for the deficiency by alternative mechanisms.

Project description:BRCA testing is recommended for young women diagnosed as having breast cancer, but little is known about decisions surrounding testing and how results may influence treatment decisions in young patients.To describe the use of BRCA testing and to evaluate how concerns about genetic risk and use of genetic information affect subsequent treatment decisions in young women with breast cancer.Cross-sectional analysis of data collected following the opening of the study to accrual from October 10, 2006, through December 31, 2014, as part of the Helping Ourselves, Helping Others: Young Women's Breast Cancer Study, an ongoing prospective cohort study. Study participants included 897 women aged 40 years and younger at breast cancer diagnosis from 11 academic and community medical centers.Frequency and trends in the use of BRCA testing and how genetic information is used to make treatment decisions among women who test positive vs negative for a BRCA mutation.A total of 780 (87.0%) of 897 women reported BRCA testing by 1 year after breast cancer diagnosis (mean age at diagnosis, 35.3 vs 36.9 years for untested women; P?<?.001), with the frequency of testing increasing among women diagnosed from August 1, 2006, through December 31, 2013. Of 39 women who were diagnosed as having breast cancer in 2006, 30 (76.9%) reported testing. In 2007, a slightly lower percentage of women (87 of 124 [70.2%]) reported testing; however, the proportion tested increased each subsequent year, with 141 (96.6%) of 146 and 123 (95.3%) of 129 women diagnosed as having breast cancer in 2012 and 2013, respectively, reporting BRCA testing (P?<?.001). Among untested women, 37 (31.6%) of 117 did not report discussion of the possibility that they might have a mutation with a physician and/or genetic counselor, and 43 (36.8%) of 117 were thinking of testing in the future. A total of 248 (29.8%) of 831 women said that knowledge or concern about genetic risk influenced treatment decisions; among these women, 76 (86.4%) of 88 mutation carriers and 82 (51.2%) of 160 noncarriers chose bilateral mastectomy (P < .001). Fewer women reported that systemic treatment decisions were influenced by genetic risk concern.Rates of BRCA1 and BRCA2 mutation testing are increasing in young women with breast cancer. Given that knowledge and concern about genetic risk influence surgical decisions and may affect systemic therapy trial eligibility, all young women with breast cancer should be counseled and offered genetic testing, consistent with the National Comprehensive Cancer Network guidelines.

Dataset Information

Association of BRCA1- and BRCA2-deficiency with mutation burden, expression of PD-L1/PD-1, immune infiltrates, and T cell-inflamed signature in breast cancer.

Publications

Association of BRCA1- and BRCA2-deficiency with mutation burden, expression of PD-L1/PD-1, immune infiltrates, and T cell-inflamed signature in breast cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets