Sunil Singhal

The metabolic reprogramming taking place during early lung adenocarcinoma progression remains poorly understood. Although early-stage lung adenocarcinoma frequently demonstrates low 2[18F]fluoro-2-deoxy-D-glucose (18FDG) uptake on positron emission tomography (PET), it is unclear whether this reflects metabolic quiescence or alternative glucose utilization pathways. We hypothesized that early lesions are metabolically active but preferentially utilize sodium–glucose cotransporter 2 (SGLT2), a noncanonical glucose transporter with low 18FDG affinity. This study investigates metabolic activity in early-stage lung adenocarcinoma and glucose transporter expression patterns across the adenocarcinoma spectrum. Lactate dehydrogenase (LDH), SGLT2, and glucose transporter-1 (GLUT1) expression was evaluated by immunohistochemistry in human lung cancers and compared with normal lung (NL) and benign inflammation. Expression levels were correlated with structural and radiologic features, including tumor size, invasion, histology, radiographic features, and PET avidity. Glycolysis was elevated in premalignant and early lung adenocarcinoma, as indicated by LDH expression. SGLT2 was highly expressed in preinvasive and minimally invasive lung adenocarcinoma compared with NL and invasive tumors. Conversely, GLUT1 was upregulated in invasive, high-grade tumors. Radiographically, SGLT2 expression was associated with subsolid nodules and low PET avidity, whereas GLUT1 expression was higher in nodules with a solid component and high 18FDG avidity. Notably, SGLT2 was not elevated in inflammatory lesions compared with NL, unlike GLUT1, which was frequently upregulated in inflammation. Early lung adenocarcinoma lesions exhibit aerobic glycolysis despite low 18FDG avidity and preferentially utilize SGLT2-mediated glucose uptake. These findings highlight a distinct metabolic profile in early lung adenocarcinoma and underscore the need for alternative imaging modalities to enhance the detection of early lesions. Prevention Relevance: This study identifies a distinct metabolic phenotype in premalignant and early-stage lung adenocarcinoma characterized by preferential SGLT2 expression and low PET avidity. These findings support the investigation of SGLT2-targeted imaging strategies to improve the detection of early lung adenocarcinoma when curative intervention is most effective.

Choline kinase α (ChoKα) is a biomarker of lung cancer, is overexpressed in 60% of human pulmonary malignancies, and is associated with an aggressive phenotype and poor clinical outcome. Patients with lung cancer who undergo surgery have a recurrence rate of 30 to 50%, indicating a potential need for better tumor detection modalities. A near-infrared fluorescent ChoKα-targeting imaging agent, JAS239 (λ _ex , λ _em : 745, 775 nanometers), was developed for intraoperative identification of tumors, their margins, and local metastases. In lung cancer cells, JAS239 inhibited phosphocholine production, reduced viability in a dose-dependent manner, and accumulated in the cytoplasm where ChoKα is active. JAS239 had favorable pharmacokinetics and pharmacodynamics for imaging metastatic lung lesions in mice. In situ and ex vivo fluorescence imaging of primary lung tumors in a canine clinical trial showed distinct tumor identification and margin delineation with a tumor-to-background ratio of 5.0 ± 0.6 and a contrast-to-variance ratio of 2.0 ± 0.2 at 0.5 milligram/kilogram. Fluorescence imaging identified a clinically significant event where an occult lesion was found after primary tumor resection. Fluorescence imaging also identified a close surgical margin, which prompted further investigation. Immunohistochemistry for ChoKα showed overexpression in canine lung tumors proportional to tumor fluorescence. Ex vivo human tumor painting demonstrated preferential JAS239 localization with a tumor-to-background ratio of 1.5 ± 0.1 and a contrast-to-variance ratio of 0.9 ± 0.1. These studies establish JAS239 as a safe and effective imaging agent for intraoperative lung tumor detection, warranting further evaluation for human patients with lung cancer.

Clade A Middle East respiratory syndrome coronavirus (MERS-CoV) spilled over from camels into humans in Saudi Arabia in 2012 and caused pneumonia and severe respiratory disease, with a 37% case fatality rate. While clade A and B viruses are closely related phylogenetically, clade B MERS-CoV strains have since outcompeted clade A strains and continue to circulate in camels and humans in the Middle East and cause outbreaks in humans. Clade C strains circulate in camels across the African continent but have not been reported to cause disease in humans. We have shown that a number of East African clade C isolates are less able to utilize the TMPRSS2-mediated pathway for viral entry in both cell lines and primary nasal epithelial cultures, which may underlie the reduced replication of East African clade C strains in humans. However, the reduced replicative capacity of West African strains in human cells appears to be independent of viral entry, suggesting an alternative basis for their attenuation. Here, we report that West African clade C MERS-CoV isolates with deletions in ORF4b encoding a key accessory protein, NS4b, induced significantly more robust interferon and inflammatory responses than clade A MERS in human respiratory cell lines and primary bronchial air–liquid interface cultures. The replication deficit for the West African strain BF785, which has a complete deletion of ORF4b, was partially rescued when RNASEL was knocked out in A549 cells. These findings demonstrate that complete loss of NS4b results in stronger innate immune activation than partial truncation and suggests that differential selection on NS4b may contribute to the varying phenotypes of clade C MERS-CoV strains circulating in African camels.

Background: Surgery is the cornerstone for locally contained lung cancer; however, intraoperative challenges include accurate lesion localization and assessment of surgical margins. Intraoperative molecular imaging (IMI) using near-infrared fluorescence-guided surgery is a real-time tumor-targeted optical imaging technique. A multicenter phase II clinical trial evaluated abenacianine (VGT-309), a cathepsin-targeted near-infrared (NIR) IMI agent for visualization of pulmonary nodules and margins during surgery. The primary objective was to assess the efficacy of abenacianine. Methods: At six sites, patients scheduled to undergo surgery for known or suspected cancer in the lung received intravenous abenacianine 0.32 mg/kg 12–36 h before surgery. Efficacy was measured by the proportion of clinically significant events, defined as localization of lesions not found by standard surgical techniques, identification of additional cancers, identification of inadequate surgical margins confirmed by histology, and detection of cancerous lymph nodes. Results: Of 89 patients who received abenacianine and surgical resection, 40 (45%) had at least one clinically significant event. Abenacianine with NIR imaging identified lesions not found by standard methods in 33 (37%) patients, synchronous and occult cancers not found by preoperative imaging in three (3%) patients, margins within 10 mm of the closest staple line in eight (9%) patients, and cancerous lymph nodes in one (1%) patient. Abenacianine was safe and well-tolerated in this study; there were no drug-related serious adverse events. Conclusions: IMI with abenacianine during standard-of-care lung cancer surgery improved intraoperative localization, identification of occult lesions, margin assessment, and lymph node detection, enabling a more complete oncologic resection.

Background/Objectives: Intraoperative molecular imaging (IMI) enables real-time visualization of tumor biology during surgery using fluorescent probes and near-infrared imaging systems. As lung cancer screening increases detection of small and nonpalpable pulmonary nodules, conventional localization and margin assessment techniques remain limited, particularly during minimally invasive surgery. This review summarizes the technical foundations, imaging agents, clinical applications, and future directions of IMI in thoracic oncology. Methods: We performed a narrative review to synthesize current evidence regarding the technical foundations, molecular imaging agents, clinical applications, and future directions of intraoperative molecular imaging in thoracic oncology. Given the multidisciplinary scope of the field, a narrative approach was selected to integrate mechanistic, translational, and clinical evidence rather than to answer a single narrowly defined clinical question. Results: IMI generates dynamic intraoperative contrast based on preferential probe accumulation or activation within malignant tissue. Current approaches include non-specific fluorophores such as indocyanine green, activatable probes targeting tumor-associated proteases or acidic microenvironments, and receptor-targeted agents such as pafolacianine. Across prospective studies and multicenter trials, IMI improved localization of nonpalpable lesions, identified occult synchronous malignancies, and enhanced intraoperative margin assessment, frequently altering surgical management. Phase 2 and 3 studies of folate receptor-targeted imaging demonstrated clinically significant findings in a substantial proportion of patients, including lesions not detected by conventional imaging or palpation. However, performance remains dependent on tumor biology, target expression, lesion depth, and optical constraints. Conclusions: IMI represents an emerging transition from anatomy-guided toward biology-informed thoracic surgery by providing real-time molecular information during resection. Current evidence supports its role as a complementary intraoperative technology that augments conventional imaging and surgical techniques, particularly for small, peripheral, and nonpalpable lesions.

Lung cancer remains the leading cause of cancer-related death, and, despite significant advancements in targeted therapy and immunotherapy, survival for patients with advanced non-small cell lung cancer (NSCLC) remains poor. An emerging area of interest is the role of epigenetic modifiers in both the pathogenesis and treatment of NSCLC. Herein, we review a selected group of chromatin-modifying genes implicated in NSCLC, organized by their function as writers (KMT2A, SETD2, and EZH2), erasers (the KDM2, KDM5, and KDM6 demethylase families), and readers (the SWI/SNF subunits SMARCA4 and ARID1A). Writers deposit activating or repressive marks on histones to regulate gene transcription, erasers remove these marks, and readers reposition nucleosomes and control DNA accessibility. Dysregulation of these genes has been associated with tumor proliferation, metastasis, treatment resistance, and altered response to immune checkpoint blockade in NSCLC. Research within this topic is emerging, and these genes represent promising potential therapeutic avenues as well as potential biomarkers. Finally, we review the clinical trials involving targeting these genes available in the current literature. The number of NSCLC-specific trials remains limited, with the most active development in SMARCA2 inhibitors for SMARCA4-mutated tumors and EZH2 inhibitors given in tandem with PD-1 blockade. We hope this review is hypothesis-generating for ongoing investigation into the role of epigenetic modifiers in NSCLC and their potential to expand the therapeutic armamentarium available for this disease.

As thoracic surgeons more frequently address smaller lung lesions and perform lung-sparing resections, their objective is to resect an adequate specimen and margin without removing excess healthy lung tissue. Although perioperative lung nodule localization has been in practice for decades, the existing and emerging techniques used for the identification of targeted and occult lesions are more widely utilized today than they were in the past. In this review, we detail the logic behind this increase in use, classify the techniques into preoperative and intraoperative categories, and define the specific modalities available. Where applicable, we review the published data comparing techniques, detailing efficacy and safety. In the preoperative space, we describe standard computed tomography (CT)-guided localization, virtual-assisted lung mapping, electromagnetic navigation bronchoscopy, robotic-assisted bronchoscopy, and novel fiducial markers. In the intraoperative space, we describe classical localization techniques, novel applications of intraoperative cone-beam CT, and fluorescence-guided surgery and intraoperative molecular imaging (IMI). Lastly, we review emerging approaches for intraoperative molecular imaging including a report on agents in early-stage clinical trials and a brief survey of promising preclinical models. With each approach mentioned, we analyze the potential benefits and hazards, and appraise the evidence for (or against) the use of any specific modality.

Purpose: Lymph node (LN) excision is critical in oncologic surgery to provide important therapeutic and diagnostic information. LN evaluation helps in staging cancers, predicting prognosis and improving survival. The ultimate wish of a surgical oncologist would be to localize and dissect all pathologically positive LNs while avoiding the morbidity of removing true negative LNs. The goal of our study was to identify a reliable marker for clinical prediction of LNs with cancer cells from non-small cell lung cancer (NSCLC) versus LNs without. We identified epithelial cell adhesion molecule (EpCAM), a membrane protein normally expressed in epithelial tissues, including in lung. Patients and Methods: We used human specimens immunostained with anti-EpCAM monoclonal antibody. Results: EpCAM was expressed in NSCLC metastasis to LNs, as shown in 74 positive LNs from patients with resected primary NSCLC. Among pathologically negative LNs, regardless of PET avidity, EpCAM was absent; whereas among pathologically positive LNs, all PET uptake groups exhibited high EpCAM positivity. Together, these biomarkers had a 100% accuracy. There was no difference in expression between hilar and mediastinal LNs, nor between primary tumor histology. Conclusions: EpCAM may be useful for the surgical oncologist for preoperative or intraoperative detection of positive LNs from NSCLC.

Photodynamic therapy (PDT) is a promising treatment for pleural malignancies, yet accurate dosimetry remains challenging due to complex cavity geometries and the need to protect surrounding critical structures. The reactive oxygen species ([ROS]_rx) generated during treatment serve as a direct predictor of therapeutic efficacy. We developed a finite element model using COMSOL Multiphysics to simulate macroscopic photophysical kinetics, using clinical data inputs, including light fluence derived from a navigation system and patient-specific photosensitizer concentrations. Crucially, we integrated a deformable image registration framework to align intra-operative navigation data with pre-treatment CT scans, enabling the calculation of [ROS]_rx dose accumulation in critical Organs at Risk (OARs), such as the lung, heart, and esophagus. The model successfully reconstructed 3D [ROS]_rx distributions for multiple clinical cases. Point-to-point comparison at 32 detector locations across ten patients showed strong agreement between COMSOL-simulated and clinically calculated [ROS]_rx (mean percentage difference 0.6 ± 5.8%), while volume-averaged values differed by −6.0%, reflecting the enhanced spatial coverage of the 3D model relative to discrete sampling. The two-stage deformable registration improved CT-to-navigation surface alignment from HD95 = 4.08 mm to 1.78 mm (56.4% reduction) and MSD = 1.77 mm to 0.68 mm (61.5% reduction), enabling the first patient-specific mapping of [ROS]_rx onto OAR structures. This study demonstrates the feasibility of a comprehensive 3D dosimetry system for pleural PDT. By integrating kinetic modeling with deformable registration, we provide a robust platform for evaluating treatment efficacy and ensuring OAR safety, paving the way for eventual integration into treatment planning and real-time feedback.