bims-tumhet Biomed News
on Tumor Heterogeneity
Issue of 2022‒03‒20
nine papers selected by
Sergio Marchini
Humanitas Research

  1. Eur J Cancer. 2022 Mar 10. pii: S0959-8049(22)00070-3. [Epub ahead of print]166 87-99
      DNA double-strand breaks are the most critical DNA damage to cells, and their repair is tightly regulated to maintain cellular integrity. Some cancers exhibit homologous recombination deficiency (HRD), a faithful double-strand break repair system, making them more sensitive to poly (ADP ribose) polymerase inhibitors (PARPi). PARPi have shown substantial efficacy in BRCA-mutated ovarian cancer for several years, and their indication has gradually been extended to other tumour locations such as breast, prostate and pancreas. More recently, PARPi were demonstrated to be effective in cancers with an HRD phenotype beyond BRCA mutations. Today, a major challenge is developing tests capable of detecting the HRD phenotype of cancers (HRD tests) and predicting sensitivity to PARPi to select patients likely to benefit from this therapy. This review provides a synthesis of the existing HRD tests, divided into three main approaches to detect HRD: the investigation of the HRD causes, the study of its consequences and the evaluation of the HR activity itself.
    Keywords:  BRCA; Genomic scars; HRD tests; Homologous recombination deficiency; PARP inhibitors; RAD51 foci
  2. Lancet Oncol. 2022 Mar 14. pii: S1470-2045(22)00122-X. [Epub ahead of print]
      BACKGROUND: Few prospective studies have compared poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors to chemotherapy for the treatment of BRCA1-mutated or BRCA2-mutated ovarian carcinoma. We aimed to assess rucaparib versus platinum-based and non-platinum-based chemotherapy in this setting.METHODS: In this open-label, randomised, controlled, phase 3 study (ARIEL4), conducted in 64 hospitals and cancer centres across 12 countries (Brazil, Canada, Czech Republic, Hungary, Israel, Italy, Poland, Russia, Spain, Ukraine, the UK, and the USA), we recruited patients aged 18 years and older with BRCA1-mutated or BRCA2-mutated ovarian carcinoma, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and who had received two or more previous chemotherapy regimens. Eligible patients were randomly assigned (2:1), using an interactive response technology and block randomisation (block size of six) and stratified by progression-free interval after the most recent platinum-containing therapy, to oral rucaparib (600 mg twice daily) or chemotherapy (administered per institutional guidelines). Patients assigned to the chemotherapy group with platinum-resistant or partially platinum-sensitive disease were given paclitaxel (starting dose 60-80 mg/m2 on days 1, 8, and 15); those with fully platinum-sensitive disease received platinum-based chemotherapy (single-agent cisplatin or carboplatin, or platinum-doublet chemotherapy). Patients were treated in 21-day or 28-day cycles. The primary endpoint was investigator-assessed progression-free survival, assessed in the efficacy population (all randomly assigned patients with deleterious BRCA1 or BRCA2 mutations without reversion mutations), and then in the intention-to-treat population (all randomly assigned patients). Safety was assessed in all patients who received at least one dose of assigned study treatment. This study is registered with, NCT02855944; enrolment is complete, and the study is ongoing.
    FINDINGS: Between March 1, 2017, and Sept 24, 2020, 930 patients were screened, of whom 349 eligible patients were randomly assigned to rucaparib (n=233) or chemotherapy (n=116). Median age was 58 years (IQR 52-64) and 332 (95%) patients were White. As of data cutoff (Sept 30, 2020), median follow-up was 25·0 months (IQR 13·8-32·5). In the efficacy population (220 patients in the rucaparib group; 105 in the chemotherapy group), median progression-free survival was 7·4 months (95% CI 7·3-9·1) in the rucaparib group versus 5·7 months (5·5-7·3) in the chemotherapy group (hazard ratio [HR] 0·64 [95% CI 0·49-0·84]; p=0·0010). In the intention-to-treat population (233 in the rucaparib group; 116 in the chemotherapy group), median progression-free survival was 7·4 months (95% CI 6·7-7·9) in the rucaparib group versus 5·7 months (5·5-6·7) in the chemotherapy group (HR 0·67 [95% CI 0·52-0·86]; p=0·0017). Most treatment-emergent adverse events were grade 1 or 2. The most common grade 3 or worse treatment-emergent adverse event was anaemia or decreased haemoglobin (in 52 [22%] of 232 patients in the rucaparib group vs six [5%] of 113 in the chemotherapy group). Serious treatment-emergent adverse events occurred in 62 (27%) patients in the rucaparib group versus 13 (12%) in the chemotherapy group; serious adverse events considered related to treatment by the investigator occurred in 32 (14%) patients in the rucaparib group and six (5%) in the chemotherapy group. Three deaths were considered to be potentially related to rucaparib (one due to cardiac disorder, one due to myelodysplastic syndrome, and one with an unconfirmed cause).
    INTERPRETATION: Results from the ARIEL4 study support rucaparib as an alternative treatment option to chemotherapy for patients with relapsed, BRCA1-mutated or BRCA2-mutated ovarian carcinoma.
    FUNDING: Clovis Oncology.
  3. Front Cell Dev Biol. 2022 ;10 854797
      Recent advances in sequencing technologies provide unprecedented opportunities for epigenetic biomarker development. Particularly the DNA methylation pattern-which is modified at specific sites in the genome during cellular differentiation, aging, and disease-holds high hopes for a wide variety of diagnostic applications. While many epigenetic biomarkers have been described, only very few of them have so far been successfully translated into clinical practice and almost exclusively in the field of oncology. This discrepancy might be attributed to the different demands of either publishing a new finding or establishing a standardized and approved diagnostic procedure. This is exemplified for epigenetic leukocyte counts and epigenetic age-predictions. To ease later clinical translation, the following hallmarks should already be taken into consideration when designing epigenetic biomarkers: 1) Identification of best genomic regions, 2) pre-analytical processing, 3) accuracy of DNA methylation measurements, 4) identification of confounding parameters, 5) accreditation as diagnostic procedure, 6) standardized data analysis, 7) turnaround time, and 8) costs and customer requirements. While the initial selection of relevant genomic regions is usually performed on genome wide DNA methylation profiles, it might be advantageous to subsequently establish targeted assays that focus on specific genomic regions. Development of an epigenetic biomarker for clinical application is a long and cumbersome process that is only initiated with the identification of an epigenetic signature.
    Keywords:  DNA methylation; IVDD; aging; biomarker; blood counts; epigenetic; hallmarks; methods
  4. J Clin Oncol. 2022 Mar 15. JCO2102011
      PURPOSE: Platinum-based chemotherapy is the standard of care for platinum-sensitive ovarian cancer, but complications from repeated platinum therapy occur. We assessed the activity of two all-oral nonplatinum alternatives, olaparib or olaparib/cediranib, versus platinum-based chemotherapy.PATIENTS AND METHODS: NRG-GY004 is an open-label, randomized, phase III trial conducted in the United States and Canada. Eligible patients had high-grade serous or endometrioid platinum-sensitive ovarian cancer. Patients were randomly assigned 1:1:1 to platinum-based chemotherapy, olaparib, or olaparib/cediranib. The primary end point was progression-free survival (PFS) in the intention-to-treat population. Secondary end points included activity within germline BRCA-mutated or wild-type subgroups and patient-reported outcomes (PROs).
    RESULTS: Between February 04, 2016, and November 13, 2017, 565 eligible patients were randomly assigned. Median PFS was 10.3 (95% CI, 8.7 to 11.2), 8.2 (95% CI, 6.6 to 8.7), and 10.4 (95% CI, 8.5 to 12.5) months with chemotherapy, olaparib, and olaparib/cediranib, respectively. Olaparib/cediranib did not improve PFS versus chemotherapy (hazard ratio [HR] 0.86; 95% CI, 0.66 to 1.10; P = .077). In women with germline BRCA mutation, the PFS HR versus chemotherapy was 0.55 (95% CI, 0.32 to 0.94) for olaparib/cediranib and 0.63 (95% CI, 0.37 to 1.07) for olaparib. In women without a germline BRCA mutation, the PFS HR versus chemotherapy was 0.97 (95% CI, 0.73 to 1.30) for olaparib/cediranib and 1.41 (95% CI, 1.07 to 1.86) for olaparib. Hematologic adverse events occurred more commonly with chemotherapy; however, nonhematologic adverse events were higher with olaparib/cediranib. In 489 patients evaluable for PROs, patients receiving olaparib/cediranib scored on average 1.1 points worse on the NFOSI-DRS-P subscale (97.5% CI, -2.0 to -0.2, P = .0063) versus chemotherapy; no difference between olaparib and chemotherapy was observed.
    CONCLUSION: Combination olaparib/cediranib did not improve PFS compared with chemotherapy and resulted in reduced PROs. Notably, in patients with a germline BRCA mutation, both olaparib and olaparib/cediranib had significant clinical activity.
  5. Front Pharmacol. 2022 ;13 777872
      Background: Systemic chemotherapy for advanced disease is another therapeutic option in the management of metastases in soft tissue sarcoma (STS). Doxorubicin either alone or in combination with ifosfamide has been used as first-line chemotherapy. Furthermore, in the past decade, new drugs have been shown to be effective in the treatment of advanced STS after the failure of first-line anthracycline-based chemotherapy: trabectedin, pazopanib and eribulin. However, the appropriate usage of these agents has not been established. Methods: We summarized clinical trials of trabectedin focusing on the efficacy and toxicity of trabectedin in the treatment of STS. Results: Trabectedin can be administered safely and effectively to the patients with advanced STS at second line setting or later. Although trabectedin may be effective as first-line treatment in selected patients, anthracycline-based chemotherapy should be recommended because no regimen in addition to trabectedin has proved to be unequivocally superior to doxorubicin as the first-line treatment for locally advanced or metastatic STS. Nucleotide excision repair (NER) and homologous recombination (HRe) repair may be of particular importance as efficacy of trabectedin. Conclusion: Trabectedin has shown a favorable toxicity profile and is an alternative therapeutic option in patients with advanced STS.
    Keywords:  advanced soft tissue sarcoma; clinical trials; progression-free survival; soft tissue sarcoma; trabectedin
  6. MedComm (2020). 2022 Mar;3(1): e116
      Whole genome amplification (WGA) is a technology for non-selective amplification of the whole genome sequence, first appearing in 1992. Its primary purpose is to amplify and reflect the whole genome of trace tissues and single cells without sequence bias and to provide sufficient DNA template for subsequent multigene and multilocus analysis, along with comprehensive genome research. WGA provides a method to obtain a large amount of genetic information from a small amount of DNA and provides a valuable tool for preserving limited samples in molecular biology. WGA technology is especially suitable for forensic identification and genetic disease research, along with new technologies such as next-generation sequencing (NGS). In addition, WGA is also widely used in single-cell sequencing. Due to the small amount of DNA in a single cell, it is often unable to meet the amount of samples needed for sequencing, so WGA is generally used to achieve the amplification of trace samples. This paper reviews WGA methods based on different principles, summarizes both amplification principle and amplification quality, and discusses the application prospects and challenges of WGA technology in molecular diagnosis and medicine.
    Keywords:  genomic DNA; isothermal amplification; molecular diagnosis; polymerase chain reaction; whole genome amplification
  7. PLoS Comput Biol. 2022 Mar 16. 18(3): e1009940
      Identifying copy number variants (CNVs) can provide diagnoses to patients and provide important biological insights into human health and disease. Current exome and targeted sequencing approaches cannot detect clinically and biologically-relevant CNVs outside their target area. We present SavvyCNV, a tool which uses off-target read data from exome and targeted sequencing data to call germline CNVs genome-wide. Up to 70% of sequencing reads from exome and targeted sequencing fall outside the targeted regions. We have developed a new tool, SavvyCNV, to exploit this 'free data' to call CNVs across the genome. We benchmarked SavvyCNV against five state-of-the-art CNV callers using truth sets generated from genome sequencing data and Multiplex Ligation-dependent Probe Amplification assays. SavvyCNV called CNVs with high precision and recall, outperforming the five other tools at calling CNVs genome-wide, using off-target or on-target reads from targeted panel and exome sequencing. We then applied SavvyCNV to clinical samples sequenced using a targeted panel and were able to call previously undetected clinically-relevant CNVs, highlighting the utility of this tool within the diagnostic setting. SavvyCNV outperforms existing tools for calling CNVs from off-target reads. It can call CNVs genome-wide from targeted panel and exome data, increasing the utility and diagnostic yield of these tests. SavvyCNV is freely available at
  8. Nat Biomed Eng. 2022 Mar 17.
      Assaying for large numbers of low-frequency mutations requires sequencing at extremely high depth and accuracy. Increasing sequencing depth aids the detection of low-frequency mutations yet limits the number of loci that can be simultaneously probed. Here we report a method for the accurate tracking of thousands of distinct mutations that requires substantially fewer reads per locus than conventional hybrid-capture duplex sequencing. The method, which we named MAESTRO (for minor-allele-enriched sequencing through recognition oligonucleotides), combines massively parallel mutation enrichment with duplex sequencing to track up to 10,000 low-frequency mutations, with up to 100-fold fewer reads per locus. We show that MAESTRO can be used to test for chimaerism by tracking donor-exclusive single-nucleotide polymorphisms in sheared genomic DNA from human cell lines, to validate whole-exome sequencing and whole-genome sequencing for the detection of mutations in breast-tumour samples from 16 patients, and to monitor the patients for minimal residual disease via the analysis of cell-free DNA from liquid biopsies. MAESTRO improves the breadth, depth, accuracy and efficiency of mutation testing by sequencing.