Ultrafast Gene Fusion Assessment for Nonsquamous NSCLC.

Introduction: Gene fusion testing of ALK, ROS1, RET, NTRK, and MET exon 14 skipping mutations is guideline recommended in nonsquamous NSCLC (NS-NSCLC). Nevertheless, assessment is often hindered by the limited availability of tissue and prolonged next-generation sequencing (NGS) testing, which can protract the initiation of a targeted therapy. Therefore, the development of faster gene fusion assessment is critical for optimal clinical decision-making. Here, we compared two ultrafast gene fusion assays (UFGFAs) using NGS (Genexus, Oncomine Precision Assay, Thermo Fisher Scientific) and a multiplex reverse-transcriptase polymerase chain reaction (Idylla, GeneFusion Assay, Biocartis) approach at diagnosis in a retrospective series of 195 NS-NSCLC cases and five extrapulmonary tumors with a known NTRK fusion. Methods: A total of 195 NS-NSCLC cases (113 known gene fusions and 82 wild-type tumors) were included retrospectively. To validate the detection of a NTRK fusion, we added five NTRK-positive extrathoracic tumors. The diagnostic performance of the two UFGFAs and standard procedures was compared. Results: The accuracy was 92.3% and 93.1% for Idylla and Genexus, respectively. Both systems improved the sensitivity for detection by including a 5'-3' imbalance analysis. Although detection of ROS1, MET exon 14 skipping, and RET was excellent with both systems, ALK fusion detection was reduced with sensitivities of 87% and 88%, respectively. Idylla had a limited sensitivity of 67% for NTRK fusions, in which only an imbalance assessment was used. Conclusions: UFGFA using NGS and reverse-transcriptase polymerase chain reaction approaches had an equal level of detection of gene fusion but with some technique-specific limitations. Nevertheless, UFGFA detection in routine clinical care is feasible with both systems allowing faster initiation of therapy and a broad degree of screening.

Longitudinal assessment of PD-L1 expression and gene expression profiles in patients with head and neck cancer reveals temporal heterogeneity.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is the most validated predictive biomarker used for the treatment of head and neck squamous cell carcinoma (HNSCC) with immune checkpoint inhibitors (ICI). Several gene expression-based signatures surrogate of the activation of IFN-gamma pathway and of the presence of tertiary lymphoid structures (TLS) have also been proposed as potential biomarkers. While they may have a potential therapeutic implication, the longitudinal changes of either PD-L1 or gene expression profiles between the initial and recurrent HNSCC lesions is unknown. METHODS: PD-L1 immunohistochemistry (IHC) and targeted RNA-sequencing of 2,549 transcripts were analyzed on paired specimens from the initial diagnosis and recurrent HNSCC. PD-L1 status was defined using the combined positive score (CPS). PD-L1 mRNA levels were compared with protein expression levels by IHC. Enrichment scores of surrogate signatures for TLS and IFN-gamma (IFN-γ) pathway activation were computed using the single sample gene set enrichment analysis (ssGSEA). RESULTS: PD-L1 status was 64% (21/33) concordant between the initial and recurrent lesions using a CPS 1 threshold and 67% (22/33) concordant using a CPS 20 threshold. CPS score was associated with PD-L1 gene expression levels. There was a 43% (15/35) and 66% (23/35) concordance for the IFN-γ and TLS signature scores, respectively. CONCLUSION: Our study reveals temporal heterogeneity of PD-L1 status and TLS/IFN-γ gene expression surrogates in HNSCC that need to be considered when interpreting biomarker studies.

Pathological assessment of cytoreductive surgery specimens and its unexplored prognostic potential-a prospective multi-centric study.

BACKGROUND AND AIM: The grade/histological subtype is one of the most important prognostic markers in patients undergoing cytoreductive surgery (CRS). Our aim was to study other potential prognostic information that can be derived from the pathological evaluation of CRS specimens and provide a broad outline for evaluation of these. METHODS: This prospective study (July to December 2018) included all patients undergoing cytoreductive surgery (CRS). A protocol for pathological evaluation was laid down which was based on existing practices at the participating centers and included evaluation of the pathological PCI, regional node involvement, response to chemotherapy, morphology of peritoneal metastases (PM) and distribution in the peritoneal cavity. RESULTS: In 191 patients undergoing CRS at 4 centers, the pathological and surgical PCI differed in over 75%. Nodes in relation to peritoneal disease were positive in 13.6%. Disease in normal peritoneum adjacent to tumor nodules was seen in >50% patients with ovarian cancer and mucinous apppendiceal tumors. 23.8% of evaluated colorectal PM patients had a complete response and 25.0% ovarian cancer patients had a near complete pathological response to chemotherapy. CONCLUSIONS: Pathological evaluation of extent and distribution of peritoneal disease differs from the surgical evaluation in majority of the patients. Lymph node involvement in relation of peritoneal disease is common. The morphological presentation of PM in ovarian cancer and mucinous appendiceal tumors merits evaluation of more extensive resections in these patients. Standardized methods of synoptic reporting of CRS specimens could help capture vital prognostic information that may in future influence how these patients are treated.