MYD88 L265P mutation and interleukin-10 detection in cerebrospinal fluid are highly specific discriminating markers in patients with primary central nervous system lymphoma: results from a prospective study.

Reliable biomarkers are needed to avoid diagnostic delay and its devastating effects in patients with primary central nervous system (CNS) lymphoma (PCNSL). We analysed the discriminating sensitivity and specificity of myeloid differentiation primary response (88) (MYD88) L265P mutation (mut-MYD88) and interleukin-10 (IL-10) in cerebrospinal fluid (CSF) of both patients with newly diagnosed (n = 36) and relapsed (n = 27) PCNSL and 162 controls (118 CNS disorders and 44 extra-CNS lymphomas). The concordance of MYD88 mutational status between tumour tissue and CSF sample and the source of ILs in PCNSL tissues were also investigated. Mut-MYD88 was assessed by TaqMan-based polymerase chain reaction. IL-6 and IL-10 messenger RNA (mRNA) was assessed on PCNSL biopsies using RNAscope technology. IL levels in CSF were assessed by enzyme-linked immunosorbent assay. Mut-MYD88 was detected in 15/17 (88%) PCNSL biopsies, with an 82% concordance in paired tissue-CSF samples. IL-10 mRNA was detected in lymphomatous B cells in most PCNSL; expression of IL-6 transcripts was negligible. In CSF samples, mut-MYD88 and high IL-10 levels were detected, respectively, in 72% and 88% of patients with newly diagnosed PCNSL and in 1% of controls; conversely, IL-6 showed a low discriminating sensitivity and specificity. Combined analysis of MYD88 and IL-10 exhibits a sensitivity and specificity to distinguish PCNSL of 94% and 98% respectively. Similar figures were recorded in patients with relapsed PCNSL. In conclusion, high detection rates of mut-MYD88 and IL-10 in CSF reflect, respectively, the MYD88 mutational status and synthesis of this IL in PCNSL tissue. These biomarkers exhibit a very high sensitivity and specificity in detecting PCNSL both at initial diagnosis and relapse. Implications of these findings in patients with lesions unsuitable for biopsy deserve to be investigated.

MYD88 L265P MUTATION DETECTION IN THE AQUEOUS HUMOR OF PATIENTS WITH VITREORETINAL LYMPHOMA.

PURPOSE: To detect the presence of MYD88 L265P mutation in the aqueous humor of patients with cytologically proven vitreoretinal lymphoma. METHODS: Eight consecutive patients with bilateral vitreoretinal lymphoma (16 eyes) were prospectively evaluated. Genomic DNA was extracted from aqueous samples after paracentesis and vitreous humor samples after diagnostic vitrectomy. MYD88 codon 265 mutation was investigated by both amplification-refractory mutation system polymerase chain reaction approach and pyrosequencing assay in the aqueous humor of all patients and in the vitreous of 6 patients. A control group of 8 age-matched patients with established diagnosis of noninfectious uveitis was also tested for the presence of MYD88 L265P mutation in the aqueous humor. RESULTS: Eight patients (three men, five women) with mean age of 69.5 years (range 50-85 years) were considered. All the patients tested for MYD88 L265P in the vitreous (six) were positive, and this result was consistent with cytological examination in all samples but one. The MYD88 L265P mutation was found in the aqueous of 6 patients (75%), and in 3 of them, the mutation was present in both eyes. Results of MYD88 L265P mutation in aqueous and vitreous sample were consistent in 7 of the 8 eyes with available samples. The aqueous humor of the noninfectious uveitis control group was negative for the detection of MYD88 L265P mutation. CONCLUSION: MYD88 mutation was detected in the aqueous humor of 75% of patients with cytologically proven vitreoretinal lymphoma. This technique may be considered as an additional diagnostic tool in the detection of the disease.

Evidence of a common cell origin in a case of pancreatic mixed intraductal papillary mucinous neoplasm-neuroendocrine tumor.

Recently, the term mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) has been proposed as an umbrella definition covering different possible combinations of mixed neuroendocrine-exocrine neoplasms. Among these, the adenoma plus neuroendocrine tumor (NET) combination is among the rarest and not formally recognized by the 2019 WHO Classification. In this setting, the debate between either collision tumors or true mixed neoplasms is still unsolved. In this report, a pancreatic intraductal papillary mucinous neoplasm (IPMN) plus a NET is described, and the molecular investigations showed the presence in both populations of the same KRAS, GNAS, and CDKN2A mutations and the amplification of the CCND1 gene. These data prove clonality and support a common origin of both components, therefore confirming the true mixed nature. For this reason, mixed neuroendocrine-exocrine neoplasms, in which the exocrine component is represented by a glandular precursor lesion (adenoma/IPMN) only, should be included into the MiNEN family.

Identification and monitoring of somatic mutations in circulating cell-free tumor DNA in lung cancer patients.

OBJECTIVES: Circulating cell-free tumor DNA (ctDNA) isolated from the peripheral blood of non-small-cell lung cancer (NSCLC) patients provides biomarkers for both therapeutic target selection, particularly when direct tumor biopsy is unfeasible, and also for drug resistance monitoring. This study evaluates the reliability and feasibility of ctDNA analysis in an in-house clinical molecular diagnostic workflow. MATERIALS AND METHODS: Mutation profiling by both standard methods and Next-Generation sequencing (NGS) was carried out and compared on 2 independent lung cancer patient cohorts. Cohort 1 consisted of 50 EGFR-mutated NSCLC patients, established on tumour biopsy, for whom ctDNA was collected at disease progression after TKI-inhibitor treatment and could be used to monitor drug resistance. Cohort 2 consisted of 50 newly diagnosed lung cancer patients for whom tumour biopsy was not possible and only ctDNA was available, providing the possibility of biomarker identification. RESULTS: ctDNA analysis of Cohort 1 verified the persistence of the tumour-detected EGFR activating mutation at disease progression by both standard and NGS methods, in 84% and 92% of the cases respectively. The T790M EGFR resistance mutation was identified in 71% of the ctDNA EGFR mutated samples providing vital information for their disease management. In newly diagnosed Cohort 2 patients, EGFR activating mutations were detected in 16% of the patients by both standard and NGS analysis of ctDNA in peripheral blood, providing indication to targeted-therapy otherwise unavailable for this group of patients. CONCLUSION: The presented study investigated lung cancer ctDNA analysis, comparing conventional methods versus NGS sequencing, and demonstrated the successful use of plasma ctDNA as a template for targeted NGS tumor gene panel in an in-house routine clinical practice. More importantly, these data underline the advantages of the clinical application of ctDNA NGS analysis for identification of therapeutic targets, real-time monitoring of therapy, and resistance mechanisms in lung cancer patients.

Rapid targeted somatic mutation analysis of solid tumors in routine clinical diagnostics.

Tumor genotyping is an essential step in routine clinical practice and pathology laboratories face a major challenge in being able to provide rapid, sensitive and updated molecular tests. We developed a novel mass spectrometry multiplexed genotyping platform named PentaPanel to concurrently assess single nucleotide polymorphisms in 56 hotspots of the 5 most clinically relevant cancer genes, KRAS, NRAS, BRAF, EGFR and PIK3CA for a total of 221 detectable mutations. To both evaluate and validate the PentaPanel performance, we investigated 1025 tumor specimens of 6 different cancer types (carcinomas of colon, lung, breast, pancreas, and biliary tract, and melanomas), systematically addressing sensitivity, specificity, and reproducibility of our platform. Sanger sequencing was also performed for all the study samples. Our data showed that PentaPanel is a high throughput and robust tool, allowing genotyping for targeted therapy selection of 10 patients in the same run, with a practical turnaround time of 2 working days. Importantly, it was successfully used to interrogate different DNAs isolated from routinely processed specimens (formalin-fixed paraffin embedded, frozen, and cytological samples), covering all the requirements of clinical tests. In conclusion, the PentaPanel platform can provide an immediate, accurate and cost effective multiplex approach for clinically relevant gene mutation analysis in many solid tumors and its utility across many diseases can be particularly relevant in multiple clinical trials, including the new basket trial approach, aiming to identify appropriate targeted drug combination strategies.