RET Fusion Testing in Patients With NSCLC: The RETING Study.

Introduction: RET inhibitors with impressive overall response rates are now available for patients with NSCLC, yet the identification of RET fusions remains a difficult challenge. Most guidelines encourage the upfront use of next-generation sequencing (NGS), or alternatively, fluorescence in situ hybridization (FISH) or reverse transcriptase-polymerase chain reaction (RT-PCR) when NGS is not possible or available. Taken together, the suboptimal performance of single-analyte assays to detect RET fusions, although consistent with the notion of encouraging universal NGS, is currently widening some of the clinical practice gaps in the implementation of predictive biomarkers in patients with advanced NSCLC. Methods: This situation prompted us to evaluate several RET assays in a large multicenter cohort of RET fusion-positive NSCLC (n = 38) to obtain real-world data. In addition to RNA-based NGS (the criterion standard method), all positive specimens underwent break-apart RET FISH with two different assays and were also tested by an RT-PCR assay. Results: The most common RET partners were KIF5B (78.9%), followed by CCDC6 (15.8%). The two RET NGS-positive but FISH-negative samples contained a KIF5B(15)-RET(12) fusion. The three RET fusions not identified with RT-PCR were AKAP13(35)-RET(12), KIF5B(24)-RET(9) and KIF5B(24)-RET(11). All three false-negative RT-PCR cases were FISH-positive, exhibited a typical break-apart pattern, and contained a very high number of positive tumor cells with both FISH assays. Signet ring cells, psammoma bodies, and pleomorphic features were frequently observed (in 34.2%, 39.5%, and 39.5% of tumors, respectively). Conclusions: In-depth knowledge of the advantages and disadvantages of the different RET testing methodologies could help clinical and molecular tumor boards implement and maintain sensible algorithms for the rapid and effective detection of RET fusions in patients with NSCLC. The likelihood of RET false-negative results with both FISH and RT-PCR reinforces the need for upfront NGS in patients with NSCLC.

Evaluation of Mucociliary Clearance by Three Dimension Micro-CT-SPECT in Guinea Pig: Role of Bitter Taste Agonists.

Different image techniques have been used to analyze mucociliary clearance (MCC) in humans, but current small animal MCC analysis using in vivo imaging has not been well defined. Bitter taste receptor (T2R) agonists increase ciliary beat frequency (CBF) and cause bronchodilation but their effects in vivo are not well understood. This work analyzes in vivo nasal and bronchial MCC in guinea pig animals using three dimension (3D) micro-CT-SPECT images and evaluates the effect of T2R agonists. Intranasal macroaggreggates of albumin-Technetium 99 metastable (MAA-Tc99m) and lung nebulized Tc99m albumin nanocolloids were used to analyze the effect of T2R agonists on nasal and bronchial MCC respectively, using 3D micro-CT-SPECT in guinea pig. MAA-Tc99m showed a nasal mucociliary transport rate of 0.36 mm/min that was increased in presence of T2R agonist to 0.66 mm/min. Tc99m albumin nanocolloids were homogeneously distributed in the lung of guinea pig and cleared with time-dependence through the bronchi and trachea of guinea pig. T2R agonist increased bronchial MCC of Tc99m albumin nanocolloids. T2R agonists increased CBF in human nasal ciliated cells in vitro and induced bronchodilation in human bronchi ex vivo. In summary, T2R agonists increase MCC in vivo as assessed by 3D micro-CT-SPECT analysis.

Carcinoma de células escamosas pigmentado. Descripción de un caso y revisión de la literatura / Pigmented squamous cell carcinoma. Case report and a review of the literatura

La mayoría de los tumores cutáneos pigmentados son melanocíticos, aunque existen otras entidades con una presentación clínica similar y estirpe epitelial, como el carcinoma de células escamosas pigmentado. Presentamos un paciente varón de 78 años con una lesión pigmentada en sien izquierda, con sospecha clínica y dermatoscópica de melanoma. Tras la exéresis, se observa una proliferación escamosa atípica infiltrante, con mitosis numerosas y que se asocia a abundantes melanófagos estromales. Tras estudio inmunohistoquímico, se evidencia una población dendrítica melanocítica acompañante, dispuesta como un entramado reticular homogéneo intratumoral, sin formación de masas ni nidos, ni atipia citológica significativa. Estos hallazgos descartan una lesión maligna bifásica escamomelanocítica, dada la ausencia de criterios de malignidad en el componente melanocítico. El carcinoma de células escamosas pigmentado es una variante infrecuente de carcinoma escamoso cutáneo y debe incluirse en el diagnóstico diferencial de las lesiones pigmentadas atípicas cutáneas y, particularmente, del melanoma y del tumor escamomelanocítico (AU)

The majority of pigmented cutaneous tumours are melanocytic, although there are other epithelial entities that are clinically similar, such as pigmented squamous cell carcinoma. We report the case of a 78 year old man who presented with a pigmented lesion on the left temple, clinically and dermoscopically suspicious of melanoma. After complete excision the lesion was seen to have infiltrating atypical squamous proliferation, with numerous mitoses and several associated stromal melanophages. Immunohistochemical studies revealed a dendritic melanocytic population, arranged in an intratumoral homogeneous reticular pattern, without mass or sheet formation or significant cytological atypia. These features rule out a malignant biphasic squamo-melanocytic lesion, based on the absence of malignant criteria in the melanocytic component. Pigmented squamous cell carcinoma is a rare variant of cutaneous squamous cell carcinoma but should be considered in the differential diagnosis of pigmented atypical cutaneous lesions, especially of melanoma and squamo-melanocytic tumour (AU)

Adjusting tidal volume to stress index in an open lung condition optimizes ventilation and prevents overdistension in an experimental model of lung injury and reduced chest wall compliance.

INTRODUCTION: The stress index (SI), a parameter derived from the shape of the pressure-time curve, can identify injurious mechanical ventilation. We tested the hypothesis that adjusting tidal volume (VT) to a non-injurious SI in an open lung condition avoids hypoventilation while preventing overdistension in an experimental model of combined lung injury and low chest-wall compliance (Ccw). METHODS: Lung injury was induced by repeated lung lavages using warm saline solution, and Ccw was reduced by controlled intra-abdominal air-insufflation in 22 anesthetized, paralyzed and mechanically ventilated pigs. After injury animals were recruited and submitted to a positive end-expiratory pressure (PEEP) titration trial to find the PEEP level resulting in maximum compliance. During a subsequent four hours of mechanical ventilation, VT was adjusted to keep a plateau pressure (Pplat) of 30 cmH2O (Pplat-group, n = 11) or to a SI between 0.95 and 1.05 (SI-group, n = 11). Respiratory rate was adjusted to maintain a 'normal' PaCO2 (35 to 65 mmHg). SI, lung mechanics, arterial-blood gases haemodynamics pro-inflammatory cytokines and histopathology were analyzed. In addition Computed Tomography (CT) data were acquired at end expiration and end inspiration in six animals. RESULTS: PaCO2 was significantly higher in the Pplat-group (82 versus 53 mmHg, P = 0.01), with a resulting lower pH (7.19 versus 7.34, P = 0.01). We observed significant differences in VT (7.3 versus 5.4 mlKg(-1), P = 0.002) and Pplat values (30 versus 35 cmH2O, P = 0.001) between the Pplat-group and SI-group respectively. SI (1.03 versus 0.99, P = 0.42) and end-inspiratory transpulmonary pressure (PTP) (17 versus 18 cmH2O, P = 0.42) were similar in the Pplat- and SI-groups respectively, without differences in overinflated lung areas at end- inspiration in both groups. Cytokines and histopathology showed no differences. CONCLUSIONS: Setting tidal volume to a non-injurious stress index in an open lung condition improves alveolar ventilation and prevents overdistension without increasing lung injury. This is in comparison with limited Pplat protective ventilation in a model of lung injury with low chest-wall compliance.