33 research outputs found
Integrating drone-borne thermal imaging with artificial intelligence to locate bird nests on agricultural land
In conservation, the use of unmanned aerial vehicles (drones) carrying various sensors and the use of deep learning are increasing, but they are typically used independently of each other. Untapping their large potential requires integrating these tools. We combine drone-borne thermal imaging with artificial intelligence to locate ground-nests of birds on agricultural land. We show, for the first time, that this semi-automated system can identify nests with a high performance. However, local weather, type of arable field and height of the drone can affect performance. The results’ implications are particularly relevant to conservation practitioners working across sectors, such as biodiversity conservation and food production in farmland. Under a rapidly changing world, studies like this can help uncover the potential of technology for conservation and embrace cross-sectoral transformations from the onset; for example, by integrating nest detection within the precision agriculture system that heavily relies on drone-borne sensors.Peer reviewe
Targeting DNA repair in Metastatic Castration-Resistant Prostate Cancer (mCRPC): Genomic Screening for a Clinical Trial of Rucaparib
Objectives: The high prevalence of men with mCRPC carrying pathogenic mutations in DNA damage repair (DDR) genes may have implications for clinical treatment, as poly(ADP-ribose) polymerase (PARP) inhibitors, such as rucaparib, have shown preliminary evidence of activity in these patients. The ongoing phase 2 TRITON2 study (NCT02952534) is evaluating rucaparib in mCRPC patients harboring a deleterious germline or somatic mutation in BRCA1, BRCA2, ATM, or other DDR gene. Here we present results from genomic screening of tissue and plasma samples from mCRPC patients.
Methods: Comprehensive genomic profiling was performed by Foundation Medicine, Inc., using FFPE tumor tissue and plasma circulating cell-free DNA (cfDNA) samples. These next-generation sequencing (NGS) assays detect germline and somatic genomic alterations (GAs), but do not distinguish between them.
Results: By Jan 15, 2019, prostate or metastatic tumor tissue samples from 1050 mCRPC patients were processed. Sequencing was successful for 68% of prostate samples, 82% of soft-tissue metastatic samples, and 57% of bone metastatic samples. In total, tissue sequencing results were obtained for 774 (74%) patients. GAs in BRCA1, BRCA2, or ATM were observed in 16.7% of patients’ tissue. In parallel, plasma from 654 mCRPC patients was collected and sequenced: 96% of plasma samples had sufficient cfDNA to obtain sequencing results, and sequencing success was independent of the location of metastases (visceral, nodal, or bone). GAs in BRCA1, BRCA2, or ATM were observed in 21.4% of patients’ plasma. There was high concordance between the alterations detected by the tissue and plasma assays. For example, in 86% of patients the plasma assay detected the same BRCA2 alteration present in tissue.
Conclusions: Genomic profiling may help guide clinical decision-making for mCRPC patients. Tumor and plasma testing successfully identified patients with eligible somatic or germline GAs for enrollment into TRITON2. These data continue to support the utilization of plasma genomic testing, particularly in patients without a lesion that can be biopsied.
Source of Funding: Clovis Oncology, Inc
A Case Study of Clinical Response to Rucaparib in a Patient with Metastatic Castration-Resistant Prostate Cancer and a RAD51B Alteration.
peer reviewedPARP inhibitors, such as rucaparib, have been well characterized in metastatic castration-resistant prostate cancer (mCRPC) associated with BRCA alterations, and the clinical activity of these agents has also been evaluated in patients with mCRPC associated with alterations in other non-BRCA DNA damage repair (DDR) genes, including RAD51B. There is likely a differential sensitivity to PARP inhibition based on the specific DDR gene altered, but research in this area is limited because of the low frequency of alterations in these genes. Here, we describe a mCRPC patient with a truncating rearrangement of RAD51B who had a radiographic and PSA response when treated with the PARP inhibitor rucaparib within the TRITON2 trial. We investigated the patients' response parameters, circulating tumor DNA (ctDNA) fraction and tumor genomics longitudinally, using next-generation sequencing (NGS) of tissue and plasma. ctDNA fraction correlates with radiographic and PSA response and is lower during times of response. NGS did not reveal any potential genomic mechanism of acquired drug resistance. This case shows evidence for rucaparib activity in a rare patient with mCRPC and a RAD51B truncation
Emergence of BRCA Reversion Mutations in Patients with Metastatic Castration-resistant Prostate Cancer After Treatment with Rucaparib.
peer reviewed[en] BACKGROUND: Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors are approved in the USA for the treatment of patients with BRCA1 or BRCA2 (BRCA) mutated (BRCA+) metastatic castration-resistant prostate cancer (mCRPC). BRCA reversion mutations are a known mechanism of acquired resistance to PARP inhibitors in multiple cancer types, although their impact and prevalence in mCRPC remain unknown.
OBJECTIVE: To examine the prevalence of BRCA reversion mutations in the plasma of patients with BRCA+ mCRPC after progression on rucaparib.
DESIGN, SETTING, AND PARTICIPANTS: Men with BRCA+ mCRPC enrolled in Trial of Rucaparib in Prostate Indications 2 (TRITON2) were treated with rucaparib after progressing on one to two lines of androgen receptor-directed and one taxane-based therapy. Cell-free DNA from the plasma of 100 patients, collected at the end of treatment after confirmed progression before May 5, 2020, was queried for BRCA reversion mutations using next-generation sequencing (NGS).
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The association of clinical efficacy and postprogression genomics was measured in 100 patients with BRCA+ mCRPC treated with rucaparib.
RESULTS AND LIMITATIONS: No baseline BRCA reversion mutations were observed in 100 BRCA+ patients. NGS identified somatic BRCA reversion mutations in 39% (39/100) of patients after progression. Reversion rates were similar for BRCA2 and BRCA1, irrespective of germline or somatic status, but higher in samples with a high tumor DNA fraction. Most patients with reversions (74%, 29/39) had two or more reversion mutations occurring subclonally at lower allele frequencies than the original BRCA mutations. The incidence of BRCA reversion mutations increased with the duration of rucaparib treatment. The frequency of reversion mutations was higher in patients with an objective (58%) or a prostate-specific antigen (69%) response compared with those without either (39% and 29%, respectively).
CONCLUSIONS: These findings suggest that BRCA reversion mutations are a significant mechanism of acquired resistance to rucaparib in patients with BRCA+ mCRPC, with evidence of subclonal convergence promoting systemic resistance.
PATIENT SUMMARY: Men with BRCA mutated metastatic castration-resistant prostate cancer enrolled in TRITON2 were treated with rucaparib after progressing on one to two lines of androgen receptor-directed and one taxane-based therapy. Cell-free DNA from the plasma of 100 patients, collected after radiographic or prostate-specific antigen progression before May 5, 2020, was analyzed by next-generation sequencing and queried for BRCA reversion mutations
Rucaparib in patients presenting a metastatic breast cancer with homologous recombination deficiency, without germline BRCA1/2 mutation
International audienceBackground: Breast cancer may present genomic alterations leading to homologous recombination deficiency (HRD). PARP inhibitors have proven their efficacy in patients with HER2-negative (HER2-) metastatic breast cancer (mBC) harbouring germline (g) BRCA1/2 mutations in 3 phases III trials. The single-arm phase II RUBY trial included 42 patients, 40 of whom received at least one dose of rucaparib. RUBY study assessed the efficacy of rucaparib in HER2-mBC with either high genomic loss of heterozygosity (LOH) score or non-germline BRCA1/2 mutation.Patients and methods: The primary objective was the clinical benefit rate (CBR), and the study was powered to see 20% CBR using a 2-stage Simon design.Results: The primary-end point was not reached with a CBR of 13.5%. Two LOH-high patients, without somatic BRCA1/2 mutation, presented a complete and durable response (12 and 28.5 months). Whole-genome analysis was performed on 24 samples, including 5 patients who presented a clinical benefit from rucaparib. HRDetect tended to be associated with response to rucaparib, without reaching statistical significance (median HRDetect responders versus non-responders: 0.465 versus 0.040; p = 0.2135). Finally, 220 of 711 patients with mBC screened for LOH upstream from RUBY presented a high LOH score associated with a higher likelihood of death (hazard ratio = 1.39; 95% CI: 1.11–1.75; p = 0.005).Conclusion Our data suggest that a small subset of patients with high LOH scores without germline BRCA1/2 mutation could derive benefit from PARP inhibitors. However, the RUBY study underlines the need to develop additional biomarkers to identify selectively potential responder
Genomic characteristics of deleterious BRCA1 and BRCA2 alterations and associations with baseline clinical factors in patients with metastatic castration-resistant prostate cancer (mCRPC) enrolled in TRITON2
Background: The phase 2 TRITON2 study (NCT02952534) is evaluating the PARP inhibitor rucaparib in patients with mCRPC who have a deleterious germline or somatic alteration in BRCA (BRCA1 or BRCA2) or 1 of 13 other DNA damage repair genes. Here we present analyses of tumor genomics and baseline clinical characteristics in mCRPC patients with a deleterious alteration in BRCA.
Methods: Plasma (baseline) and tissue (archival or baseline) samples from patients with a deleterious alteration in BRCAwere analyzed using Foundation Medicine next-generation sequencing assays. The alterations and zygosity of the alterations that were detected, as well as the somatic/germline status from Color Genomics testing, were summarized. Associations between genomic alterations, DNA yield, allele frequency, and baseline clinical characteristics were investigated.
Results: Results are shown in the Table for a cohort of 40 BRCA2 and 5 BRCA1 patients enrolled in TRITON2 (Abida W et al. Presented at ESMO 2018. Abst 793PD). A biallelic alteration was observed in 21 of the 22 BRCA2 patients (95%) for whom alteration zygosity could be determined. Among the 5 BRCA1 patients, 1 alteration was monoallelic and 4 were of unknown zygosity. Co-occurring alterations in cancer-related or DNA damage repair genes were observed in many patients with BRCA alterations. At baseline, cell-free DNA (cfDNA) yield correlated positively with the sum of target lesions (STL; P= 0.04), but not with prostate-specific antigen (PSA) levels (P= 0.86). No correlation was observed between allele frequency of the BRCA alteration baseline STL (P= 0.68) or PSA levels (P= 0.97).
Conclusions: Patients with a BRCA mutation enrolled in TRITON2 demonstrate a profile of genomic alterations consistent with that of prior studies of patients with mCRPC. Plasma cfDNA profiling showed a correlation between baseline cfDNA yield and measurable tumor burden, but not baseline PSA. Clinical trial information: NCT0295253
Genomic Profiles of De Novo High- and Low-Volume Metastatic Prostate Cancer: Results From a 2-Stage Feasibility and Prevalence Study in the STAMPEDE Trial
PURPOSE: The STAMPEDE trial recruits men with newly diagnosed, high-risk, hormone-sensitive prostate cancer. To ascertain the feasibility of targeted next-generation sequencing (tNGS) and the prevalence of baseline genomic aberrations, we sequenced tumor and germline DNA from patients with metastatic prostate cancer (mPCa) starting long-term androgen-deprivation therapy (ADT). METHODS: In a 2-stage approach, archival, formalin-fixed, paraffin-embedded (FFPE) prostate tumor core biopsy samples were retrospectively subjected to 2 tNGS assays. Prospective enrollment enabled validation using tNGS in tumor and germline DNA. RESULTS: In stage 1, tNGS data were obtained from 185 tumors from 287 patients (65%); 98% had de novo mPCa. We observed PI3K pathway aberrations in 43%, due to PTEN copy-number loss (34%) and/or activating mutations in PIK3 genes or AKT (18%) and TP53 mutation or loss in 33%. No androgen receptor (AR) aberrations were detected; RB1 loss was observed in < 1%. In stage 2, 93 (92%) of 101 FFPE tumors (biopsy obtained within 8 months) were successfully sequenced prospectively. The prevalence of DNA damage repair (DDR) deficiency was 14% (somatic) and 5% (germline). BRCA2 mutations and mismatch repair gene mutations were exclusive to high-volume disease. Aberrant DDR (22% v 15%), Wnt pathway (16% v 4%), and chromatin remodeling (16% v 8%) were all more common in high-volume compared with low-volume disease, but the small numbers limited statistical comparisons. CONCLUSION: Prospective genomic characterization is feasible using residual diagnostic tumor samples and reveals that the genomic landscapes of de novo high-volume mPCa and advanced metastatic prostate cancer have notable similarities (PI3K pathway, DDR, Wnt, chromatin remodeling) and differences (AR, RB1). These results will inform the design and conduct of biomarker-directed trials in men with metastatic hormone-sensitive prostate cancer