Expanding Broad Molecular Reflex Testing in Non-Small Cell Lung Cancer to Squamous Histology

Due to the success story of biomarker-driven targeted therapy, most NSCLC guidelines agree that molecular reflex testing should be performed in all cases with non-squamous cell carcinoma (non-SCC). In contrast, testing recommendations for squamous cell carcinoma (SCC) vary considerably, specifically concerning the exclusion of patients of certain age or smoking status from molecular testing strategies. We performed a retrospective single-center study examining the value of molecular reflex testing in an unselected cohort of 316 consecutive lung SCC cases, tested by DNA- and RNA-based next-generation sequencing (NGS) at our academic institution between 2019 and 2023. Clinicopathological data from these cases were obtained from electronic medical records and correlated with sequencing results. In 21/316 (6.6%) cases, we detected an already established molecular target for an approved drug. Among these were seven cases with an EGFR mutation, seven with a KRAS G12C mutation, four with an ALK fusion, two with an EGFR fusion and one with a METex14 skipping event. All patients harboring a targetable alteration were >50 years of age and most of them had >15 pack-years, questioning restrictive molecular testing strategies. Based on our real-world data, we propose a reflex testing workflow using DNA- and RNA-based NGS that includes all newly diagnosed NSCLC cases, irrespective of histology, but also irrespective of age or smoking status.

Reflex testing in non-small cell lung carcinoma using DNA- and RNA-based next-generation sequencing-a single-center experience

Background

Targeted treatment modalities for non-small cell lung carcinoma (NSCLC) patients are expanding rapidly and demand a constant adaptation of molecular testing strategies. In this regard, broad reflex testing via next-generation sequencing (NGS) might have several advantages. However, real-world data regarding practical feasibility and clinical relevance are scarce, especially for RNA-based NGS.

Methods

We performed a retrospective study comparing NGS use in two consecutive years (2019 and 2020). In 2019, reflex testing mainly consisted of DNA-based NGS for mutations and immunohistochemistry (IHC) for ALK, ROS1, and NTRK fusion products. At the beginning of 2020, our approach has changed, with DNA- and RNA-based NGS panels now being simultaneously performed. This change in protocol allowed us to retrospectively evaluate if broad molecular reflex testing brings additional value to lung cancer patients.

Results

Within the whole cohort (n=432), both DNA- and RNA-based NGS yielded almost always evaluable results. Only in 6 cases, the RNA content was too little for an appropriate analysis. After integrating RNA-based NGS in the reflex testing approach, the number of detected fusions increased significantly (2.6% vs. 8.2%; P=0.0021), but also more patients received targeted therapies. Furthermore, exceedingly rare alterations were more likely to be detected, including the so far undescribed EGFR-NUP160 fusion.

Conclusions

Our study demonstrates that a comprehensive approach to reflex NGS testing is practically feasible and clinically relevant. Including RNA-based panels in the reflex testing approach results in more detected fusions and more patients receiving targeted therapies. Additionally, this broad molecular profiling strategy identifies patients with emerging biomarkers, underscoring its usefulness in the rapidly evolving landscape of targeted therapies.

Fetal Rhabdomyoma of the upper Extremity in a 31-Year Old Patient: a Case Report

Fetal rhabdomyomas (RM) are extremely rare benign mesenchymal tumours that occur primarily in the head and neck. This tumour exhibits immature skeletal muscle differentiation. The patients' median age is four years and surgical resection is the recommended treatment. Fetal RM of limbs are rare and not well described in the literature and if, predominantly in form of case reports. We report the second case of a fetal RM in the upper extremity in a 31-year old male patient. One should be aware of this skeletal muscle tumour and fetal RM should be considered as a differential diagnosis to its malignant counterpart rhabdomyosarcoma.

Detection of GNAS mutations in intramuscular / cellular myxomas as diagnostic tool in the classification of myxoid soft tissue tumors

BACKGROUND

Intramuscular / cellular myxomas and low-grade myxofibrosarcomas are two different tumor entities with a significant histological overlap, especially if dealing with small biopsies. Despite the morphological similarities, they differ considerably in their biological behaviour. Intramuscular / cellular myxoma rarely shows signs of recurrence and never metastasizes, in contrast to myxofibrosarcoma that tends to recur more aggressively and to metastasize haematologically. Therefore, it is of great importance to distinguish these lesions - evaluation of GNAS mutation status could be of tremendous help.

METHODS

We reviewed 13 cases with intramuscular / cellular myxomas. The 13 cases included 5 men and 8 women, aged from 33 to 71 years (mean age 55.5 years). Immunohistochemistry was performed as well as next generation sequencing. Ten cases were located in the lower extremities and three cases were located in the upper extremities. Two lesions were initially misdiagnosed as a low-grade myxofibrosarcoma.

RESULTS

Performing next generation sequencing 12 out of 13 specimens showed a GNAS mutation.

CONCLUSIONS

Our findings demonstrate that GNAS mutations are more common in intramuscular / cellular myxomas, than had been reported in literature in the past. Next generation sequencing for determining GNAS mutation status on small biopsies or diagnostically challenging cases facilitates the diagnosis of intramuscular / cellular myxoma and separates this tumor entity from its mimics.

Influence of eukaryotic translation initiation factor 6 on non-small cell lung cancer development and progression

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Dysregulation of protein synthesis plays a major role in carcinogenesis, a process regulated at multiple levels, including translation of mRNA into proteins. Ribosome assembly requires correct association of ribosome subunits, which is ensured by eukaryotic translation initiation factors (eIFs). eIFs have become targets in cancer therapy studies, and promising data on eIF6 in various cancer entities have been reported. Therefore, we hypothesised that eIF6 represents a crossroad for pulmonary carcinogenesis. High levels of eIF6 are associated with shorter patient overall survival in adenocarcinoma (ADC), but not in squamous cell carcinoma (SQC) of the lung. We demonstrate significantly higher protein expression of eIF6 in ADC and SQC than in healthy lung tissue based on immunohistochemical data from tissue microarrays (TMAs) and on fresh frozen lung tissue. Depletion of eIF6 in ADC and SQC lung cancer cell lines inhibited cell proliferation and induced apoptosis. Knockdown of eIF6 led to pre-rRNA processing and ribosomal 60S maturation defects. Our data indicate that eIF6 is upregulated in NSCLC, suggesting an important contribution of eIF6 to the development and progression of NSCLC and a potential for new treatment strategies against NSCLC.

Occult solitary submucosal jejunal metastasis from esophageal carcinoma

BACKGROUND

Metastatic tumors of the intestinal tract from extra-abdominal sites are rare. In esophageal cancer, the liver, lung and the bones are the most common sites of metastases. Metastasis to intestines are very rare.

CASE PRESENTATION

A 54-year old male was admitted with esophageal squamous cell carcinoma (SCC) associated with dysphagia II-III and weight loss of 20 kg. Preoperative routine staging failed to detect any metastases. A transthoracic esophagectomy and orthotopic gastric pull-up with collar esophago-gastrostomy, associated with 2-field lymphadenectomy was performed. During the digital placement of the naso-jejunal feeding catheter a submucosal jejunal nodule with a diameter of 1 cm, about 40 cm distal to the duodeno-jejunal fold was detected which was completely resected by jejunotomy. Histopathology of jejunal nodule showed metastasis from esophageal squamous cell carcinoma.

CONCLUSION

Because of the extensive esophageal lymphatic system, an occult widespread dissemination of the tumor cells into the abdominal cavity is possible. Additional intraoperative evaluation of the small intestine and the complete abdominal cavity should be performed in every operation of esophageal carcinoma to detect possible occult intraabdominal metastases.

Immunohistochemical detection of tumor necrosis factor-alpha, other cytokines and adhesion molecules in human livers with alcoholic hepatitis

This immunohistochemical study was designed to investigate the possible contribution to and topographical distribution of some important cytokines, such as tumour necrosis factor alpha (TNF alpha) and interleukins, in acute alcoholic hepatitis. The well-known inductive capacity of these cytokines with respect to the expression and/or up-regulation of adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1), was a further point to be studied. Moreover, the proposed induction of adhesion molecules might also be associated with the activation and attraction of a special population of inflammatory cells characteristic for alcoholic hepatitis. Frozen liver samples from patients who died with signs of acute alcoholic hepatitis were evaluated using the alkaline phosphatase anti-alkaline phosphatase immunostaining technique and also single and double indirect immunofluorescence. In acute alcoholic hepatitis TNF alpha could be detected predominantly in ballooned hepatocytes, which often contained alcoholic hyalin (Mallory bodies). Moreover, TNF alpha showed a co-distribution with ICAM-1 expressed in the membranes of hepatocytes and with the occurrence of CD11b positive polymorphonuclear leukocytes (neutrophils) suggesting a possible major role of the beta 2-integrin Mac-1 as a ligand for ICAM-1. No induction of ELAM-1 could be found. In alcoholic hepatitis cytokines may be responsible for the induction of the adhesion molecule ICAM-1 on hepatocytic membranes and activate a defined population of inflammatory cells, thus contributing to the characteristic histological picture of acute alcoholic hepatitis with its concentration of neutrophils especially in areas with ballooned Mallory body-containing hepatocytes. Our results are in line with clinical findings showing high levels of TNF alpha and interleukin-1 in sera of patients with alcoholic hepatitis and with the already reported expression of ICAM-1 on hepatocytes.