Five cases of thoracic solitary fibrous tumor (SFT) with small cell features are presented mimicking a neuroendocrine neoplasm. The patients were four men and one woman aged 43 to 74 years who presented with symptoms of chest pain, cough, dyspnea or hemoptysis. Two tumors were intrapulmonary neoplasms, while three were pleural-based. Grossly, the tumors ranged in size from 4 to 6 cm and were white and solid; in two tumors necrosis was apparent. Histologically, they were characterized by a cellular proliferation composed of small cells with round nuclei and inconspicuous nucleoli. The cellular proliferation in some areas had a subtle nested pattern, while in other areas the tumor showed extensive sclerosis and small vessel proliferation. Cellular pleomorphism was not marked and the mitotic activity varied from 1 to 5 mitotic figures per 10 high power fields. Microscopically, necrosis was observed in two cases and focally present in one. Immunohistochemical stains showed tumors cells universally negative for pancytokeratin; in the two pulmonary cases, focal staining for synaptophysin, CD56, and INSM1 was observed. The unexpected lack of expression of pancytokeratin led to additional analysis revealing positive staining with CD34 and STAT6 confirming a diagnosis of SFT. Clinical follow-up showed tumor recurrence in one patient while three patients remained alive and well after a period of 12 to 20 months. The current cases highlight an unusual variant of SFT that may be confused with other small cell tumor entities, such as neuroendocrine or neuroectodermal tumors, especially when originating in the thoracic cavity.

We present an interesting case of mediastinal small cell carcinoma (MSCC), an exceedingly rare entity, comorbid with idiopathic pulmonary fibrosis (IPF). A 66-year-old female was first seen in the pulmonology office for abnormal chest computed tomography (CT) findings of right apical bronchiectasis and subpleural fibrotic changes with focal pleural thickening along the fissures, along with a right lower lobe nodule. Pulmonary function testing (PFT) showed an obstructive pattern with modest bronchodilator response, although subsequent PFT showed a worsening restrictive pattern with a worsening DLCO. On a follow-up CT one year later, a soft tissue density with peripheral calcification was found in the anterior mediastinum, later found to be hypermetabolic on a PET scan. Radiographically, fibrosis worsened with the appearance of worsening diffuse bilateral coarse reticular interstitial changes with lower lobe predominance, honeycombing, and areas of ground-glass opacity. A biopsy of the mediastinal lesion showed a high-grade neuroendocrine tumor. Cam5.2, insulinoma-associated protein-1, synaptophysin, and thyroid transcription factor-1 immunostains were positive. She underwent four cycles of chemotherapy with cisplatin and etoposide with a total of 60 Gy of radiation. Mediastinal mass started to decrease in size. Her respiratory status, imaging, and PFTs continued to show evidence of IPF progression. Prednisone resulted in modest clinical and radiographic response. Steroid-sparing therapy with mycophenolate mofetil, although effective, had to be discontinued due to GI bleeding. Anti-fibrotic therapy was deferred due to evidence showing a lack of clinical improvement. We discuss the existing evidence available on IPF management and proceed to highlight the deficiencies in existing data available on the management of IPF and MSCC in these patients. Most of the cases of MSCC reported in the past have managed MSCC using guidance from treatment practices for small cell lung cancer. No reported cases discuss or describe the management of IPF and MSCC in the very rare cohort of patients our case represents.

UNASSIGNED: Targeting the tumor microenvironment may enhance response to immunotherapy (immune checkpoint inhibitors) and improve outcomes for patients. This study tested the safety and efficacy of vorolanib, a novel tyrosine kinase inhibitor of vascular endothelial growth factor, platelet-derived growth factor, and c-KIT, in combination with programmed cell death protein 1 blockade using nivolumab for refractory thoracic malignancies.
UNASSIGNED: This single-arm multicenter study enrolled patients with extensive-stage SCLC, thymic carcinoma, and NSCLC, either naive or had progressed on previous chemotherapy or immune checkpoint inhibitors (either primary or acquired resistance). The primary objective of phase 1 was to determine the maximum tolerated dose, and the primary end point for each dose-expansion cohort was the objective response rate.
UNASSIGNED: A total of 88 patients were enrolled in phase 1 (n = 11) and dose expansion (n = 77) cohorts. Transaminitis was dose-limiting and expansion proceeded with oral vorolanib 200 mg daily combined with intravenous nivolumab 240 mg every 2 weeks. The objective response rate per cohort were as follows: NSCLC naive 33% (five of 15, 95% confidence interval [CI]: 13%-60%), NSCLC primary refractory 5.9% (one of 17, 95% CI: 0%-17.6%), NSCLC acquired resistance 11.1% (two of 18, 95% CI: 0%-27.8%); SCLC 0% (zero of 18), and thymic carcinoma 11% (one of nine, 95% CI: 0%-33%). Disease control rate ranged from 11.1% in SCLC (two of 18, 0%-27.8%) to 66.7 % in thymic carcinoma (six of nine, 95% CI: 33.3%-100%). The most common adverse events were fatigue (32%), aspartate transaminase (27%) and alanine transaminase elevation (25%), and diarrhea (19%). Transaminitis was more common in patients with thymic carcinoma than other tumors.
UNASSIGNED: Vorolanib plus nivolumab had a manageable safety profile and may have clinical benefits in various thoracic malignancies. The disease control rate in thymic malignancies warrants further assessment.

Trans-differentiation from an adenocarcinoma to a small cell neuroendocrine state is associated with therapy resistance in multiple cancer types. To gain insight into the underlying molecular events of the trans-differentiation, we perform a multi-omics time course analysis of a pan-small cell neuroendocrine cancer model (termed PARCB), a forward genetic transformation using human prostate basal cells and identify a shared developmental, arc-like, and entropy-high trajectory among all transformation model replicates. Further mapping with single cell resolution reveals two distinct lineages defined by mutually exclusive expression of ASCL1 or ASCL2. Temporal regulation by groups of transcription factors across developmental stages reveals that cellular reprogramming precedes the induction of neuronal programs. TFAP4 and ASCL1/2 feedback are identified as potential regulators of ASCL1 and ASCL2 expression. Our study provides temporal transcriptional patterns and uncovers pan-tissue parallels between prostate and lung cancers, as well as connections to normal neuroendocrine cell states.

Prostate cancer is typically of acinar adenocarcinoma type but can occasionally present as neuroendocrine and/or ductal type carcinoma. These are associated with clinically aggressive disease, and the former often arises on a background of androgen deprivation therapy, although it can also arise de novo. Two prostate cancer cases were sequenced by exome capture from archival tissue. Case 1 was de novo small cell neuroendocrine carcinoma and ductal adenocarcinoma with three longitudinal samples over 5 years. Case 2 was a single time point after the development of treatment-related neuroendocrine prostate carcinoma. Case 1 showed whole genome doubling in all samples and focal amplification of AR in all samples except the first time point. Phylogenetic analysis revealed a common ancestry for ductal and small cell carcinoma. Case 2 showed 13q loss (involving RB1) in both adenocarcinoma and small cell carcinoma regions, and 3p gain, 4p loss, and 17p loss (involving TP53) in the latter. By using highly curated samples, we demonstrate for the first time that small-cell neuroendocrine and ductal prostatic carcinoma can have a common ancestry. We highlight whole genome doubling in a patient with prostate cancer relapse, reinforcing its poor prognostic nature.

Small cell lung cancer is an aggressive subtype of lung cancer with limited treatment options. Precision medicine has revolutionized cancer treatment for many tumor types but progress in SCLC has been slower due to the lack of targetable biomarkers. This review article provides an overview of emerging strategies for precision therapy in SCLC. Targeted therapies include targeted kinase inhibitors, monoclonal antibodies, angiogenesis inhibitors, antibody-drug conjugates, PARP inhibitors, and epigenetic modulators. Angiogenesis inhibitors and DNA-damaging agents, such as PARP and ATR inhibitors, have been explored in SCLC with limited success to date although trials are ongoing. The potential of targeting DLL3, a NOTCH ligand, through antibody-drug conjugates, bispecific T-cell engagers, and CAR T-cell therapy, has opened up new therapeutic options moving forward. Additionally, new research in epigenetic therapeutics in reversing transcriptional repression, modulating anti-tumor immunity, and utilizing antibody-drug conjugates to target cell surface-specific targets in SCLC are also being investigated. While progress in precision therapy for SCLC has been challenging, recent advancements provide optimism for improved treatment outcomes. However, several challenges remain and will need to be addressed, including drug resistance and tumor heterogeneity. Further research and biomarker-selected clinical trials are necessary to develop effective precision therapies for SCLC patients.

Concurrent chemoradiotherapy (CRT) is the standard of care for limited-stage small cell lung cancer (LS-SCLC). Local therapy-surgery or stereotactic body radiotherapy (SBRT)-with adjuvant chemotherapy may be appropriate for very early (T1-T2, N0) disease. There is variability in the management of these cases, which may lead to variability in patient outcomes. This study aimed to determine practice patterns for the management of very early LS-SCLC in Canada. A survey was developed and distributed to Canadian medical and radiation oncologists specialising in lung cancer. The survey consisted of three sections: (1) physician demographics, (2) general practice approach, and (3) preferred approach for three clinical scenarios (1: peripheral T1 lesion; 2: central T1 lesion; 3: peripheral T2 lesion). Responses were analysed to detect differences across cases and among physician groups. There were 77 respondents. In case 1, assuming medical operability, most respondents (73%) chose surgery and adjuvant chemotherapy, with 19% choosing CRT. CRT was selected by a higher proportion in case 2 (48%) and case 3 (61%) (p < 0.05). If medically inoperable, most chose CRT over local therapy in all cases, with more choosing CRT in case 2 (84%) and case 3 (86%) than in case 1 (55%) (p < 0.05). Subgroup analysis showed a predilection towards CRT in Western Canada and among more experienced physicians, and towards SBRT in Ontario. There is variability in the management of very early LS-SCLC in Canada. CRT remains the most popular strategy in most cases, with surgery preferred for small peripheral lesions. Larger and more central tumours are more likely to be managed with CRT. Variation in practice is correlated with region and physician experience. Our study illustrates the variability in the management of very early LS-SCLC in Canada and highlights the need for more robust investigations into the ideal approach for these patients.

De novo neuroendocrine prostate cancer (NEPC) and treatment-emergent neuroendocrine prostate cancer (T-NEPC) are rare diseases with a poor prognosis. After first-line platinum chemotherapy, there is no consensus on second-line treatments.
Patients with a pathologic diagnosis of de novo NEPC or T-NEPC between 2000 and 2020 who received first-line platinum and any second-line systemic therapy were selected and standardized clinical data was collected via the electronic health record at each institution. The primary endpoint was overall survival (OS) based on second-line therapy. Secondary endpoints included objective response rate (ORR) to second-line therapy, PSA response, and time on treatment.
Fifty-eight patients (32 de novo NEPC, 26 T-NEPC) from 8 institutions were included. At de novo NEPC or T-NEPC diagnosis, the overall cohort had a median age of 65.0 years (IQR 59.2-70.3) and median PSA of 3.0 ng/dL (IQR 0.6-17.9). Following first-line platinum chemotherapy, 21 patients (36.2%) received platinum chemotherapy, 10 (17.2%) taxane monotherapy, 11 (19.0%) immunotherapy, 10 (17.2%) other chemotherapy, and 6 (16.2%) other systemic therapy. Among 41 evaluable patients, the ORR was 23.5%. The mOS after start of second-line therapy was 7.4 months (95% CI 6.1-11.9).
In this retrospective study, patients with de novo NEPC or T-NEPC who received second-line therapy were treated with wide variety of treatment regimens, reflecting the lack of consensus in this setting. Most patients received chemotherapy-based treatments. Overall prognosis was poor and ORR was low in the second line regardless of treatment choice.

Plant growth and development rely heavily on cyclins, which comprise an important class of cell division regulators. D-type cyclins (CYCDs) are responsible for the rate-limiting step of G1 cells. In the plant kingdom, despite the importance of CYCDs in herbaceous plants, there is little knowledge of these proteins in perennial woody plants. Here, the gene of a nucleus-localized cyclin, PsnCYCD1;1, was cloned from Populus simonii × P. nigra. PsnCYCD1;1 was highly expressed in tissues with active cell division, especially the leaf buds, and could be induced by sucrose and phytohormones. Moreover, overexpression of PsnCYCD1;1 in poplar could stimulate cell division, resulting in the generation of small cells and causing severe morphological changes in the vascular bundles, resulting in \'S\'-shaped tortuous stems and curled leaves. Furthermore, transcriptomic analysis revealed that endogenous genes related to cell division and vascular cambium development were significantly up-regulated in the transgenic plants. In addition, using yeast two-hybrid and bimolecular fluorescence complementation assays PsnCDKA1, PsnICK3, and PsnICK5 were identified as proteins interacting with PsnCYCD1;1. Our study demonstrates that PsnCYCD1;1 accelerates plant cell division and participates in secondary growth of vascular bundles in poplar.

BACKGROUND: Large cell neuroendocrine carcinoma (LCNEC) of the lung is a rare, aggressive cancer most commonly found in the lungs but not exclusively, with a worse prognosis than non-small cell lung carcinomas. Currently, LCNEC patients are treated using small cell and non-small cell protocols. This study aims to use the SEER database to identify demographic, clinical, pathological, and therapeutic factors affecting the prognosis and survival of patients with LCNEC of the lung.
METHODS: Demographic, clinical, and management data of patients with lung LCNEC were extracted from the SEER database for the period 2000-2018.
RESULTS: In the USA, LCNEC has a higher incidence in elderly white men: M:F ratio = 1.2:1, Caucasian: 83.3%, mean age: 67 ± 10.2 years. The most common treatment modality was chemotherapy only: 29.2%, followed by surgery: 21.5% (but in this group the statuses of chemotherapy were unknown), and combination surgery/chemotherapy: 8.8%. The overall and cause-specific 5-year survival was 17.5% (95% CI 16.3-18.8) and 21.9% (95% CI 20.5-23.4), respectively. By treatment, the best 5-year survival was for surgery alone (48%), followed by multimodality therapy (chemo + surgery + radiation) at 35% (95% CI 27-43). Age > 60 years, male gender, size > 7 cm, and nodal and liver metastasis were independent risk factors associated with increased mortality.
CONCLUSIONS: Lung LCNEC is an aggressive neoplasm most common in older white males that presents at an advanced stage despite small primary tumors. Most patients die within 2 years. The best predictor of survival is surgery with chemotherapy. Given its dismal prognosis, new treatment guidelines are needed for this aggressive cancer.