Successive next-generation sequencing strategy for optimal fusion gene detection in non-small-cell lung cancer in clinical practice.

Metastatic non-small-cell lung cancer (NSCLC) displays various molecular alterations in the RAS-MAPK pathway. In particular, NSCLCs show high rates of targetable gene fusion in ALK, RET, ROS1, NRG1 and NTRK, or MET exon 14 skipping. Rapid and accurate detection of gene fusion in EGFR/KRAS/BRAF mutations is important for treatment selection especially for first-line indications. RNA-based next-generation sequencing (NGS) panels appear to be the most appropriate as all targets are multiplexed in a single run. While comprehensive NGS panels remain costly for daily practice, optimal sequencing strategies using targeted DNA/RNA panel approaches need to be validated. Here, we describe our lung cancer screening strategy using DNA and RNA targeted approaches in a real-life cohort of 589 NSCLC patients assessed for molecular testing. Gene fusions were analysed in 174 patients negative for oncogene driver mutations or ALK immunohistochemistry in a two-step strategy. Targetable alterations were identified in 28% of contributive samples. Non-smokers had a 63.7% probability to have a targetable alteration as compared to 21.5% for smokers. Overall survival was significantly higher (p=0.03) for patients who received a molecularly matched therapy. Our study shows the feasibility in routine testing of NSCLC DNA/RNA molecular screening for all samples in a cost- and time-controlled manner. The significant high fusion detection rate in patients with wild-type RAS-MAPK tumours highlights the importance of amending testing strategies in NSCLC.

An atypical promyelocytic sarcoma and pleural effusion in a patient with Gorham's disease: Efficiency of ATRA/ATO-based treatment.

Key Clinical Message: This is the first case of a promyelocytic sarcoma diagnosed on pleural effusion and exposed the difficulty of demonstrating a leukemic phase in patients with bone diseases, such as Gorham's disease. It also showed that promyelocytic sarcoma can be treated by ATRA/ATO-based therapy with an efficient and tolerated response. Abstract: Myeloid sarcoma (MS) is a rare extramedullary tumoral infiltration of immature myeloid cells and can occur in different sites of the body, without leukemic infiltration. A 38-year-old woman patient presented at emergency with a pleural effusion, bicytopenias, and Gorham's disease, a very rare bone disorder. In the following days, she worsened with a chylothorax and pancytopenias. Pleural puncture cytologically revealed promyelocytes with Auer rods. Cytogenetic and molecular analyses subsequently confirmed the presence of the t(15:17) translocation. However, no circulating phase of these atypical promyelocytes was found. Similarly, no other origin was identified. We conclude that the patient had a MS of unknown etiology in the form of a pleural effusion with pathological promyelocytes. The patient was treated with a combination of oral all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) with a cytological and molecular remission persisting 3 months after diagnosis. We report here the first case of a promyelocytic MS of pleural origin without concomitant evidence of acute promyelocytic leukemia. We also show the efficacy of ATRA/ATO treatment in this etiology.

Baseline circulating tumour DNA and total metabolic tumour volume as early outcome predictors in aggressive large B-cell lymphoma. A real-world 112-patient cohort.

Approximately 20%-50% of patients with large B-cell lymphoma (LBCL) experience poor outcomes. We aimed to evaluate the combined prognostic value of circulating tumour DNA (ctDNA) and total metabolic tumour volume (TMTV) in LBCL. This observational single-centre study included 112 newly diagnosed LBCL patients, receiving R-CHOP/R-CHOP-like chemotherapies. CtDNA load was calculated following next-generation sequencing of cell-free DNA (cfDNA) using a targeted 40-gene lymphopanel. TMTV was measured using a fully automated artificial intelligence-based method for lymphoma lesion segmentation. CtDNA was detected in cfDNA samples from 95 patients with a median concentration of 3.15 log haploid genome equivalents per mL. TMTV measurements were available for 102 patients. The median TMTV was 501 mL. High ctDNA load (>3.57 log hGE/mL) or high TMTV (>200 mL) were associated with shorter 1-year PFS (44% vs. 83%, p < 0.001 and 64% vs. 97%, p = 0.002, respectively). When combined, three prognostic groups were identified. The shortest PFS was observed when both TMTV and ctDNA load were high (p < 0.001). Even with a short follow up, combining ctDNA load with TMTV improved the risk stratification of patients with aggressive LBCL. In the near future, very high-risk patients could benefit from CAR T-cell therapy or bispecific antibodies as first-line treatments.