Extracellular RNA (cell‐free RNA; exRNA) from blood‐derived liquid biopsies is an appealing, minimally invasive source of disease biomarkers. As pre‐analytical variables strongly influence exRNA measurements, their reporting is essential for meaningful interpretation and replication of results. The aim of this review was to chart to what extent pre‐analytical variables are documented, to pinpoint shortcomings and to improve future reporting. In total, 200 blood plasma exRNA studies published in 2018 or 2023 were reviewed for annotation of 22 variables associated with blood collection, plasma preparation, and RNA purification. Our results show that pre‐analytical variables are poorly documented, with only three out of 22 variables described in over half of the publications. The percentage of variables reported ranged from 4.6% to 54.6% (mean 24.84%) in 2023 and from 4.6% to 57.1% (mean 28.60%) in 2018. Recommendations and guidelines (i.e., BRISQ, ASCO‐CAP, BloodPAC, PPMPT, and CEN standards) have currently not resulted in improved reporting. In conclusion, our results highlight the lack of reporting pre‐analytical variables in exRNA studies and advocate for a consistent use of available standards, endorsed by funders and journals.

Patients with primary Sjogren’s syndrome (pSS) are at risk of developing extranodal marginal zone lymphoma (ENMZL) of the mucosa-associated lymphoid tissue (MALT) in the parotid glands. Unlike recurrent genomic aberrations observed in MALT lymphoma, which were not associated with pSS (non-pSS), it is unknown which somatic aberrations underlie the development of pSS-associated MALT lymphomas. Whole-exome sequencing was performed on 17 pSS-associated MALT lymphomas. In total, 222 nonsynonymous somatic variants affecting 182 genes were identified across the 17 cases. The median number of variants was seven (range 2–78), including three cases with a relatively high mutational load (≥24/case). Out of 16 recurrently mutated genes, ID3, TBL1XR1, PAX5, IGLL5 and APC are known to be associated with lymphomagenesis. A total of 18 copy number alterations were detected in eight cases. MALT1 translocations were not detected. With respect to outcome, only two cases relapsed outside of the salivary glands. Both had a high mutational load, suggesting a more advanced stage of lymphoma. The low mutational load and lack of a clear lymphoma-related mutation profile suggests that localized pSS-associated MALT lymphomas are genomically more stable than non-pSS MALT lymphomas and most likely depend on a stimulatory micro-environment.

The risk of relapse among high-risk patients with diffuse large B-cell lymphoma (DLBCL) in complete metabolic remission (CMR) after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy is 20% to 25%. Here, we evaluated whether consolidation with the programmed cell death ligand 1 checkpoint inhibitor atezolizumab could reduce the relapse risk. In this phase 2, open-label trial, patients with DLBCL with an International Prognostic Index (IPI) score of ≥3 and CMR after R-CHOP received 1200 mg atezolizumab every 3 weeks for 18 cycles. The primary end point was disease-free survival (DFS) at 2 years, with the aim of improving it to 89% compared to historical 79%. Secondary end points included overall survival (OS) and safety (Common Terminology Criteria for Adverse Events version 4.0). Analyses were on an intention-to-treat principle. Of 109 patients, 65% completed treatment. The cohort was 59% males, with 63% having high-intermediate risk IPI scores. At a median follow-up of 36.4 months, 15 relapses occurred (median, 8.2 months). The 2-year DFS was 87.9% (90% confidence interval [CI], 81.5-92.1), and the 2-year OS was 96.3% (90% CI, 91.7-98.3), meeting the primary objective. Treatment with salvage chemotherapy resulted in 10 of 13 patients achieving a second CMR. OS was significantly better among atezolizumab-treated patients than in a population-based matched control cohort from the Netherlands Cancer Registry. Adverse events (AEs) affected 79% of patients, with 18% developing immune-related AEs, including 4.5% grade 3 to 4. Atezolizumab consolidation significantly improved DFS in high-risk patients with DLBCL compared to historical cohorts. OS was significantly better than a population-based control cohort. These findings warrant further validation and assessment of immune checkpoint inhibitors as consolidation strategy in DLBCL. This trial was registered at www.clinicaltrials.gov as #NCT03463057.