Osteosarcoma: Novel prognostic biomarkers using circulating and cell-free tumour DNA

AIM: Osteosarcoma (OS) is the most common primary bone tumour in children and adolescents. Circulating free (cfDNA) and circulating tumour DNA (ctDNA) are promising biomarkers for disease surveillance and prognostication in several cancer types; however, few such studies are reported for OS. The purpose of this study was to discover and validate methylation-based biomarkers to detect plasma ctDNA in patients with OS and explore their utility as prognostic markers. METHODS: Candidate CpG markers were selected through analysis of methylation array data for OS, non-OS tumours and germline samples. Candidates were validated in two independent OS datasets (n = 162, n = 107) and the four top-performing markers were selected. Methylation-specific digital droplet PCR (ddPCR) assays were designed and experimentally validated in OS tumour samples (n = 20) and control plasma samples. Finally, ddPCR assays were applied to pre-operative plasma and where available post-operative plasma from 72 patients with OS, and findings correlated with outcome. RESULTS: Custom ddPCR assays detected ctDNA in 69% and 40% of pre-operative plasma samples (n = 72), based on thresholds of one or two positive markers respectively. ctDNA was detected in 5/17 (29%) post-operative plasma samples from patients, which in four cases were associated with or preceded disease relapse. Both pre-operative cfDNA levels and ctDNA detection independently correlated with overall survival (p = 0.0015 and p = 0.0096, respectively). CONCLUSION: Our findings illustrate the potential of mutation-independent methylation-based ctDNA assays for OS. This study lays the foundation for multi-institutional collaborative studies to explore the utility of plasma-derived biomarkers in the management of OS

MYC amplifications are common events in childhood osteosarcoma.

Funder: Bone Cancer Research Trust; Id: http://dx.doi.org/10.13039/100011719Funder: The Tom Prince Cancer TrustFunder: Wellcome Trust; Id: http://dx.doi.org/10.13039/100010269Funder: Jean Shanks Foundation – Pathological Society Clinical FellowshipFunder: UCL Experimental Cancer CentreFunder: UCLH Biomedical Research Centre; Id: http://dx.doi.org/10.13039/501100012317Funder: National Institute for Health Research; Id: http://dx.doi.org/10.13039/501100000272Osteosarcoma, the most common primary malignant tumour of bone, affects both children and adults. No fundamental biological differences between paediatric and adult osteosarcoma are known. Here, we apply multi-region whole-genome sequencing to an index case of a 4-year-old child whose aggressive tumour harboured high-level, focal amplifications of MYC and CCNE1 connected by translocations. We reanalysed copy number readouts of 258 cases of high-grade osteosarcoma from three different cohorts and identified a significant enrichment of focal MYC, but not CCNE1, amplifications in children. Furthermore, we identified four additional cases of MYC and CCNE1 coamplification, highlighting a rare driver event which warrants further investigation. Our findings indicate that amplification of the MYC oncogene is a major driver of childhood osteosarcoma, while CCNE1 appears recurrently amplified independent of age

Acute HTLV-1 leukemia/ lymphoma in a 33 year old grenadian migrant: A case report

We present a case of an acute HTLV-1 leukemia in a 33-year-old Grenadian immigrant. Her diffuse skin nodules, and her coming from an area endemic for HTLV-1, namely the Caribbean made the clinical diagnosis of HTLV-1 leukemia/lymphoma more feasible. Her disease was rapidly progressive, she having survived for one month, and fits into the acute classification of ATLL as proposed by Shimyoyama M. Immigrants from areas endemic for HTLV-1 who presents with skin rashes should be investigated for HTLV-1 neoplasms

Recurrent FOSL1 rearrangements in desmoplastic fibroblastoma.

Funder: Bone Cancer Research Trust; Id: http://dx.doi.org/10.13039/100011719Funder: Cancer Research UK; Id: http://dx.doi.org/10.13039/501100000289Funder: Jean Shanks Foundation; Id: http://dx.doi.org/10.13039/501100001308Funder: NIHR Biomedical Research Centre, Royal Marsden NHS Foundation Trust/Institute of Cancer Research; Id: http://dx.doi.org/10.13039/100014461Funder: Pathological Society of Great Britain and Ireland; Id: http://dx.doi.org/10.13039/501100000672Funder: Tom Prince TrustThe FOS gene family has been implicated in tumourigenesis across several tumour types, particularly mesenchymal tumours. The rare fibrous tumour desmoplastic fibroblastoma is characterised by overexpression of FOSL1. However, previous studies using cytogenetic and molecular techniques did not identify an underlying somatic change involving the FOSL1 gene to explain this finding. Prompted by an unusual index case, we report the discovery of a novel FOSL1 rearrangement in desmoplastic fibroblastoma using whole-genome and targeted RNA sequencing. We investigated 15 desmoplastic fibroblastomas and 15 fibromas of tendon sheath using immunohistochemistry, in situ hybridisation and targeted RNA sequencing. Rearrangements in FOSL1 and FOS were identified in 10/15 and 2/15 desmoplastic fibroblastomas respectively, which mirrors the pattern of FOS rearrangements observed in benign bone and vascular tumours. Fibroma of tendon sheath, which shares histological features with desmoplastic fibroblastoma, harboured USP6 rearrangements in 9/15 cases and did not demonstrate rearrangements in any of the four FOS genes. The overall concordance between FOSL1 immunohistochemistry and RNA sequencing results was 90%. These findings illustrate that FOSL1 and FOS rearrangements are a recurrent event in desmoplastic fibroblastoma, establishing this finding as a useful diagnostic adjunct and expanding the spectrum of tumours driven by FOS gene family alterations. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland