Cancer Genetics and Therapeutic Opportunities in Urologic Practice

Outcomes of a universal germline screening program in a community urology practice

The role of germline genetic testing in urologic oncology has expanded in recent years. However, implementation of genetic testing in community practices remains a challenge, often due to limited access to qualified genetics trained providers. In this study, we report outcomes of a universal germline screening program in a community urology practice. Between November 2021 and September 2022, all patients referred for urology clinic visits at Frederick Health (Frederick, MD, USA) were provided an online genetics screening questionnaire prior to the visit. Responses were compared against National Comprehensive Cancer Network (NCCN) criteria for germline testing. Those who met criteria were provided educational materials at the end of the questionnaire, and then counseled by a trained urologic oncologist (HC) in the clinic or referred to a genetic counselor prior to testing. Testing was performed with a 36-gene pan-cancer panel (CancerNext) or a 14-gene targeted prostate cancer panel (ProstateNext), with or without additional RNA analysis (RNAinsight) (Ambry Genetics, CA, USA). Demographic and clinical parameters, as well as genetic testing results, were retrospectively collected under IRB approval. In the study period, 765 patients were seen over 1370 clinic visits. Of these, 505 patients (66.0%) completed the screening questionnaire. The majority were completed via email (54.5%) with the remainder (45.5%) via text message. Of the patients who completed screening, 125/505 (24.7%) met NCCN criteria for germline testing. 58/125 patients (46.4%) who met criteria underwent germline testing, of whom 5/58 (8.6%) had distinct pathogenic mutations identified. These included actionable mutations in BRCA1, BRCA2, and CHEK2, as well as an additional pathogenic mutation in NBN. Variants of unknown significance were identified in 8/58 patients (13.8%) in 11 total genes. Challenges to implementation of this program included meeting institutional requirements for genetic testing consent, facilitating specimen collection in clinic, and integration of results into the electronic health record. Genetic risk assessment for high-risk individuals is feasible as part of a universal screening program in a community urology practice. Approximately 8% of tested patients were found to have pathogenic germline mutations, which is consistent with contemporary tertiary referral cohorts.

Mapping the tumor microenvironment in clear cell renal carcinoma by single-cell transcriptome analysis

Introduction: Clear cell renal cell carcinoma (ccRCC) is associated with unfavorable clinical outcomes. To identify viable therapeutic targets, a comprehensive understanding of intratumoral heterogeneity is crucial. In this study, we conducted bioinformatic analysis to scrutinize single-cell RNA sequencing data of ccRCC tumor and para-tumor samples, aiming to elucidate the intratumoral heterogeneity in the ccRCC tumor microenvironment (TME). Methods: A total of 51,780 single cells from seven ccRCC tumors and five para-tumor samples were identified and grouped into 11 cell lineages using bioinformatic analysis. These lineages included tumor cells, myeloid cells, T-cells, fibroblasts, and endothelial cells, indicating a high degree of heterogeneity in the TME. Copy number variation (CNV) analysis was performed to compare CNV frequencies between tumor and normal cells. The myeloid cell population was further re-clustered into three major subgroups: monocytes, macrophages, and dendritic cells. Differential expression analysis, gene ontology, and gene set enrichment analysis were employed to assess inter-cluster and intra-cluster functional heterogeneity within the ccRCC TME. Results: Our findings revealed that immune cells in the TME predominantly adopted an inflammatory suppression state, promoting tumor cell growth and immune evasion. Additionally, tumor cells exhibited higher CNV frequencies compared to normal cells. The myeloid cell subgroups demonstrated distinct functional properties, with monocytes, macrophages, and dendritic cells displaying diverse roles in the TME. Certain immune cells exhibited pro-tumor and immunosuppressive effects, while others demonstrated antitumor and immunostimulatory properties. Conclusion: This study contributes to the understanding of intratumoral heterogeneity in the ccRCC TME and provides potential therapeutic targets for ccRCC treatment. The findings emphasize the importance of considering the diverse functional roles of immune cells in the TME for effective therapeutic interventions.

Association of differential expression of immunoregulatory molecules and presence of targetable mutations may inform rational design of clinical trials

Background

Immune checkpoint inhibitors (ICIs) and genomic biomarker-driven targeted therapies have revolutionized the modern oncologic treatment arsenal. The next step has been to combine targeted agents and ICIs. In doing so, some combination regimens may be more logical than others.

Patients and methods

Whole-exome and whole-transcriptome sequencing were performed on 2739 unselected later-stage clinical cases from 24 solid tumor subtypes in the NantHealth database, and data were also curated from 5746 similarly sequenced patients across 28 solid tumor subtypes in The Cancer Genome Atlas (TCGA). Significant differential expression of 10 immunoregulatory molecules [IRMs (genes)] was analyzed for association with mutant versus wild-type genes.

Results

Twenty-three significant associations between currently actionable variants and RNA-expressed checkpoint genes were identified in the TCGA cases; 10 were validated in the external cohort of 2739 clinical cases from NantHealth (P values were adjusted using Benjamini–Hochberg multiple hypothesis correction to reduce false-discovery rate). Within the same 5746 TCGA profiles, 2740 TCGA patients were identified as having one or more potentially oncogenic single-nucleotide variant (SNV) mutation within an established 50-gene hotspot panel. Of the 50 genes, SNVs within 15 were found to be significantly associated with differential expression of at least one IRM after adjusting for tissue enrichment; six were confirmed significant associations in an independent set of 2739 clinical cases from NantHealth.

Conclusions

Logically combining ICIs with targeted therapies may offer unique treatment strategies for patients with cancer. The presence of specific mutations impacts the expression of IRMs, an observation of potential importance for selecting combinations of gene- and immune-targeted therapeutics.

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Altered actionable genes correlated with specific checkpoint transcripts.

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Associations between IRMs and altered genes were validated in independent datasets.

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Combining immune- and gene-targeted drugs based on IRM/gene correlations merits study.