Neuroendocrine differentiation distinguishes basaloid variant of lung squamous cell carcinoma

Targeting PI3K/AKT/mTOR signaling to overcome drug resistance in cancer

This review comprehensively explores the challenge of drug resistance in cancer by focusing on the pivotal PI3K/AKT/mTOR pathway, elucidating its role in oncogenesis and resistance mechanisms across various cancer types. It meticulously examines the diverse mechanisms underlying resistance, including genetic mutations, feedback loops, and microenvironmental factors, while also discussing the associated resistance patterns. Evaluating current therapeutic strategies targeting this pathway, the article highlights the hurdles encountered in drug development and clinical trials. Innovative approaches to overcome resistance, such as combination therapies and precision medicine, are critically analyzed, alongside discussions on emerging therapies like immunotherapy and molecularly targeted agents. Overall, this comprehensive review not only sheds light on the complexities of resistance in cancer but also provides a roadmap for advancing cancer treatment.

Survival comparison of pulmonary neuroendocrine carcinoma, adenocarcinoma with neuroendocrine differentiation, and adenocarcinoma

Background

Pulmonary adenocarcinoma with neuroendocrine differentiation (ADE_ned) is a relatively uncommon pathological classification, and there exists considerable debate regarding its prognosis and treatment. The purpose of this study was to analyze the survival difference between patients with neuroendocrine carcinoma (NEC), adenocarcinoma (ADE), or ADE_ned and to investigate the prognostic factors influencing the outcomes of individuals diagnosed with pulmonary ADE_ned.

Methods

We retrieved information on 316 cases of ADE_ned, 188,823 cases of ADE, and 71,154 cases of NEC diagnosed between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. To account for potential confounding variables, propensity score matching (PSM) was employed. Comparative analyses were conducted to estimate the overall survival (OS) and cancer-specific survival (CSS). Finally, the Cox regression models were used to identify prognostic factors associated with pulmonary ADE_ned.

Results

Prior to PSM, patients with lung ADE_ned had a worse OS rate than did those with lung ADE or NEC (5-year OS rate: 13.3% vs. 26.6% vs. 15.6%; P<0.001 and P=0.009, respectively). In terms of CSS, the 5-year CSS rate of patients with ADE_ned was superior to that of NEC but inferior to that of ADE (28.7% vs. 26.8% vs. 43.8%; P=0.006 and P<0.001, respectively). Following PSM, the 5-year survival rate of patients with ADE_ned remained lower than that of individuals with ADE or NEC in terms of OS (13.3% vs. 24.4% vs. 23.0%; P<0.001 and P<0001, respectively) and CSS (28.8% vs. 58.6% vs. 43.1%; P<0.001 and P=0.006, respectively). Finally, the results of the competitive risk regression analysis demonstrated that several variables, including sex, T stage, N stage, M stage, and surgery, were found to be independent prognostic factors for patients diagnosed with pulmonary ADE_ned (all P values <0.05).

Conclusions

Patients with lung ADE_ned had a significantly poorer survival outcome compared to those with lung ADE or NEC. Furthermore, sex, tumor-node-metastasis (TNM) stage, and surgery were found to be independent prognostic indicators for cases with lung ADE_ned.

Pulmonary squamous cell carcinoma and lymphoepithelial carcinoma - morphology, molecular characteristics and differential diagnosis

Squamous cell carcinoma (SCC) comprises one of the major groups of non-small-cell carcinoma of the lung, and is subtyped into keratinising, non-keratinising and basaloid SCC. SCC can readily be diagnosed using histomorphology alone in keratinising SCC. Confirmatory immunohistochemical analyses should always be applied in non-keratinising and basaloid tumours to exclude differential diagnoses, most prominently adenocarcinoma and high-grade neuroendocrine carcinoma, which may have important therapeutic consequences. According to the World Health Organisation (WHO) classification 2015, the diagnosis of SCC can be rendered in resections of morphologically ambiguous tumours with squamous immunophenotype. In biopsies and cytology preparations in the same setting the current guidelines propose a diagnosis of 'non-small-cell carcinoma, favour SCC' in TTF1-negative and p40-positive tumours to acknowledge a possible sampling bias and restrict extended immunohistochemical evaluation in order to preserve tissue for molecular testing. Most SCC feature a molecular 'tobacco-smoke signature' with enrichment in GG > TT mutations, in line with the strong epidemiological association of SCC with smoking. Targetable mutations are extremely rare but they do occur, in particular in younger and non- or light-smoking patients, warranting molecular investigations. Lymphoepithelial carcinoma (LEC) is a poorly differentiated SCC with a syncytial growth pattern and a usually prominent lymphoplasmacytic infiltrate and frequent Epstein-Barr virus (EBV) association. In this review, we describe the morphological and molecular characteristics of SCC and LEC and discuss the most pertinent differential diagnoses.

Role of radiotherapy in the management of rare solid thoracic tumors of the adults

Thoracic tumors include more than one hundred histopathological subtypes. Rare thoracic malignancies can be defined as representing less than 1% of all thoracic tumors. The European Rare Cancer Surveillance Project (RARECARE) identified rarity as an incidence less than 6 for 100,000 people, with significant difference of prevalence between them. Modalities of treatment for these pathologies include surgery, radiotherapy, and systemic therapies. In this article, we aim to discuss role and techniques of radiotherapy in management of rare solid thoracic tumors in adults, focusing on different anatomical locations such as lung parenchyma, mediastinum, vessels, chest wall and pleural cavity.

POU2F3 in SCLC: Clinicopathologic and Genomic Analysis With a Focus on Its Diagnostic Utility in Neuroendocrine-Low SCLC

INTRODUCTION

POU2F3 is a recent marker of a small cell lung carcinoma (SCLC) subtype related to chemosensory tuft cells (SCLC-P). The characteristics of SCLC-P have not been fully defined, and the data on POU2F3 expression in other lung tumors are scarce.

METHODS

We screened 254 SCLC for POU2F3 expression and comprehensively analyzed histopathologic, genomic, and clinical characteristics of POU2F3-positive tumors. We also explored POU2F3 expression in other major lung cancer types (n = 433) and a targeted set of potential diagnostic mimics of SCLC (n = 123).

RESULTS

POU2F3 was expressed in 30 of 254 (12%) SCLC and was strongly associated with low expression of standard neuroendocrine markers (synaptophysin, chromogranin A, CD56, INSM1). Notably, POU2F3 was expressed in 75% of SCLC with entirely negative or minimal neuroendocrine marker expression (15/20) and was helpful in supporting the diagnosis of SCLC in such cases. Broad targeted next-generation sequencing revealed that SCLC-P (n = 12) exhibited enrichment in several alterations, including PTEN inactivation, MYC amplifications, and 20q13 amplifications, but similar rates of RB1 and TP53 alterations as other SCLC (n = 155). Beyond SCLC, POU2F3 expression was exclusively limited to large cell neuroendocrine carcinoma (12%) and basaloid squamous cell carcinoma (22%).

CONCLUSIONS

This is the largest cohort of SCLC-P clinical samples to date, where we describe the diagnostic utility of POU2F3 in a challenging subset of SCLC with low or absent expression of standard neuroendocrine markers. The distinct genomic alterations in SCLC-P may offer a novel avenue for therapeutic targeting. The role of POU2F3 in a narrow subset of other lung cancer types warrants further study.