Integrative molecular analysis of combined small-cell lung carcinomas identifies major subtypes with different therapeutic opportunities

The molecular and metabolic landscape of ferroptosis in respiratory diseases: Pharmacological aspects

Ferroptosis is a form of cell death that occurs when there is an excess of reactive oxygen species (ROS), lipid peroxidation, and iron accumulation. The precise regulation of metabolic pathways, including iron, lipid, and amino acid metabolism, is crucial for cell survival. This type of cell death, which is associated with oxidative stress, is controlled by a complex network of signaling molecules and pathways. It is also implicated in various respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), lung cancer, pulmonary fibrosis (PF), and the coronavirus disease 2019 (COVID-19). To combat drug resistance, it is important to identify appropriate biological markers and treatment targets, as well as intervene in respiratory disorders to either induce or prevent ferroptosis. The focus is on the role of ferroptosis in the development of respiratory diseases and the potential of targeting ferroptosis for prevention and treatment. The review also explores the interaction between immune cell ferroptosis and inflammatory mediators in respiratory diseases, aiming to provide more effective strategies for managing cellular ferroptosis and respiratory disorders.

The expression of YAP1 and other transcription factors contributes to lineage plasticity in combined small cell lung carcinoma

Lineage plasticity in small cell lung carcinoma (SCLC) causes therapeutic difficulties. This study aimed to investigate the pathological findings of plasticity in SCLC, focusing on combined SCLC, and elucidate the involvement of YAP1 and other transcription factors. We analysed 100 surgically resected SCLCs through detailed morphological observations and immunohistochemistry for YAP1 and other transcription factors. Component-by-component next-generation sequencing (n = 15 pairs) and immunohistochemistry (n = 35 pairs) were performed on the combined SCLCs. Compared with pure SCLCs (n = 65), combined SCLCs (n = 35) showed a significantly larger size, higher expression of NEUROD1, and higher frequency of double-positive transcription factors (p = 0.0009, 0.04, and 0.019, respectively). Notably, 34% of the combined SCLCs showed morphological mosaic patterns with unclear boundaries between the SCLC and its partner. Combined SCLCs not only had unique histotypes as partners but also represented different lineage plasticity within the partner. NEUROD1-dominant combined SCLCs had a significantly higher proportion of adenocarcinomas as partners, whereas POU2F3-dominant combined SCLCs had a significantly higher proportion of squamous cell carcinomas as partners (p = 0.006 and p = 0.0006, respectively). YAP1 expression in SCLC components was found in 80% of combined SCLCs and 62% of pure SCLCs, often showing mosaic-like expression. Among the combined SCLCs with component-specific analysis, the identical TP53 mutation was found in 10 pairs, and the identical Rb1 abnormality was found in 2 pairs. On immunohistochemistry, the same abnormal p53 pattern was found in 34 pairs, and Rb1 loss was found in 24 pairs. In conclusion, combined SCLC shows a variety of pathological plasticity. Although combined SCLC is more plastic than pure SCLC, pure SCLC is also a phenotypically plastic tumour. The morphological mosaic pattern and YAP1 mosaic-like expression may represent ongoing lineage plasticity. This study also identified the relationship between transcription factors and partners in combined SCLC. Transcription factors may be involved in differentiating specific cell lineages beyond just 'neuroendocrine'.

Genomic and transcriptomic profiling of combined small-cell lung cancer through microdissection: unveiling the transformational pathway of mixed subtype

BACKGROUND

Combined small-cell lung carcinoma (cSCLC) represents a rare subtype of SCLC, the mechanisms governing the evolution of cancer genomes and their impact on the tumor immune microenvironment (TIME) within distinct components of cSCLC remain elusive.

METHODS

Here, we conducted whole-exome and RNA sequencing on 32 samples from 16 cSCLC cases.

RESULTS

We found striking similarities between two components of cSCLC-LCC/LCNEC (SCLC combined with large-cell carcinoma/neuroendocrine) in terms of tumor mutation burden (TMB), tumor neoantigen burden (TNB), clonality structure, chromosomal instability (CIN), and low levels of immune cell infiltration. In contrast, the two components of cSCLC-ADC/SCC (SCLC combined with adenocarcinoma/squamous-cell carcinoma) exhibited a high level of tumor heterogeneity. Our investigation revealed that cSCLC originated from a monoclonal source, with two potential transformation modes: from SCLC to SCC (mode 1) and from ADC to SCLC (mode 2). Therefore, cSCLC might represent an intermediate state, potentially evolving into another histological tumor morphology through interactions between tumor and TIME surrounding it. Intriguingly, RB1 inactivation emerged as a factor influencing TIME heterogeneity in cSCLC, possibly through neoantigen depletion.

CONCLUSIONS

Together, these findings delved into the clonal origin and TIME heterogeneity of different components in cSCLC, shedding new light on the evolutionary processes underlying this enigmatic subtype.

Sustained Clinical Response to 4th-Line Therapy with Selpercatinib in RET Fusion-Positive Combined Small Cell Lung Cancer

Objective

Combined small cell lung cancer (C-SCLC) is a relatively rare subtype of small cell lung cancer (SCLC) which combines SCLC and any component of non-small cell carcinoma (NSCLC). Patients diagnosed with C-SCLC are currently recommended to receive the same treatment as SCLC cases in the absence of clear evidence suggesting different strategies. The genomic profiling of C-SCLC is rarely studied. Herein, we report a case of extensive-stage C-SCLC harboring the KIF5B-RET fusion before first-line therapy and with persistent sensitivity to fourth-line selpercatinib treatment is reported.

Materials and Methods

Molecular and pathological features were evaluated using transbronchial lung biopsy, immunohistochemical (IHC) staining and next-generation sequencing (NGS).

Results

NGS revealed the KIF5B-RET fusion in the C-SCLC tumor. The patient had a progression-free survival (PFS) surpassing 14 months after selpercatinib treatment, with ongoing clinical response in 4th-line treatment.

Conclusion

This case highlights the importance of comprehensive molecular testing in C-SCLC for selecting the optimal treatment. Although RET fusion is rare in patients with C-SCLC, its identification and treatment with selective RET inhibitors may contribute to clinical benefits.

Prognostic significance of eighth edition TNM stage criteria in combined small-cell lung cancer

Objectives

This study aimed to evaluate the prognostic significance of the eighth edition TNM stage criteria in patients with combined small-cell lung cancer (C-SCLC) on a population level.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER) database, patients diagnosed with C-SCLC (histology code 8245) between the years 2004 and 2015 were identified. We performed a Kaplan–Meier analysis and used the multivariable cox regression proportional hazards model to obtain prognostic overall survival estimates for each group of patients.

Results

A total of 477 patients diagnosed with C-SCLC were identified. The T, N, M, TNM, and combined TNM stage status of the eighth edition were all significant prognostic factors for patients’ overall survivals, with the best discrimination identified in the combined stages. Surgery was also found to be a prognostic factor (HR =1.95, 95%CI =1.49-2.56, p<0.01) for patients with C-SCLC.

Conclusions

The combined eighth edition of the TNM staging criteria shows reliable prognostic significance in patients with C-SCLC. Moreover, surgery might be significant for improving the patients’ prognosis.

Clinicopathological and Treatment Patterns of Combined Small-Cell Lung Carcinoma with Future Insight to Treatment: A Population-Based Study

BACKGROUND

Primary lung cancer is the most common cause of cancer-related mortality in the United States (US). Approximately 90% of lung cancers are associated with smoking and the use of other tobacco products. Based on histology, lung cancers are divided into small-cell lung carcinomas (SCLCs) and non-small-cell lung carcinomas (NSCLCs). Most SCLCs are of the pure subtype, while the rare combined SCLCs contain elements of both small-cell and non-small-cell morphologies. This study sought to evaluate the demographics, clinical factors, molecular abnormalities, treatment approaches, and survival outcomes with combined SCLC and NSCLCs.

MATERIALS AND METHODS

Data on 2126 combined SCLC patients was extracted from the Surveillance Epidemiology and End Result (SEER) database from 2000 to 2018. Data extracted for analyses included age, sex, race, tumor size, tumor location, metastasis status, stage at diagnosis, treatment received, and treatment outcomes. Multivariate analysis was performed using Statistical Product and Service Solutions (SPSS) software.

RESULTS

The patients had a median age of 68 years; 43.9% of the patients were female and 56.1% were male; 84.5% were White and 11.7% were African Americans. The majority of patients had a poorly differentiated disease at 29.6%; 17% were undifferentiated, 3.2% were moderately differentiated, and 0.8% were well differentiated. Chemotherapy was the most common treatment modality (45.3%); 17% underwent surgery only, 10.3% underwent surgery followed by adjuvant chemotherapy, and 10% underwent radiation after surgery. Five-year cancer-specific survival was 15.2% with surgery alone, and combined surgery and chemotherapy provided the highest percentages (38.3% and 34.7%, respectively). Females had significantly higher 1- and 5-year cancer-specific survival rates compared to males (59.3% and 29.9% vs. 48.0% and 23.7, respectively; p < 0.001). Well-differentiated tumors had significantly higher survival compared to other gradings (p < 0.001). Survival decreased as tumor staging moved distally from localized to regional to distant (p < 0.001). Metastasis to bone, liver, brain, and lung significantly decreased survival in comparison to patients who did not have any metastasis (p < 0.001). Females had significantly shorter survival compared to their counterparts when metastasis was to the bone, brain, or liver (p < 0.001). Multivariate analysis identified male sex (Hazard Ratio (HR) = 1.2), undifferentiated grade (HR = 1.9), regional extent of disease (HR = 1.7), distant extent of disease (HR = 3.7), and metastasis to liver (HR = 3.5) as variables associated with worse survival.

CONCLUSION

Combined SCLC is overall very rare. However, the frequency of presentation with combined SCLC is on the rise, in part due to improvements in diagnostic techniques. Despite advances in therapies, treating combined SCLC is challenging, and novel therapies are not utilized, owing to low rates of targetable mutations. Combined SCLC has higher survival rates if well differentiated.

Clinical Efficacy of Single-Port Thoracoscopic Lobectomy versus Three-Port Thoracoscopic Lobectomy for Lung Cancer

Objective

To evaluate the clinical efficacy of single-port thoracoscopic lobectomy versus three-port thoracoscopic lobectomy for lung cancer.

Methods

From February 2020 to February 2021, 200 lung cancer patients treated in our institution assessed for eligibility were enrolled and randomly assigned (1 : 1) to either the experimental group (single-port thoracoscopic lobectomy) or the control group (three-port thoracoscopic lobectomy). The outcomes were the eligible patients' surgical indices, pain stress indexes, and postoperative complications.

Results

The experimental group outperformed the control group in terms of incision length, postoperative drainage time, extubation time, time to get out of bed, time to analgesics administration, and postoperative pain score (P < 0.001). Compared with the control group, the experimental group reduced the intraoperative bleeding (161.98 ± 10.65 versus 179.65 ± 14.20, P < 0.001) and length of hospital stay (7.98 ± 0.56 versus 10.46 ± 1.23, P < 0.001). The operative time of the single-port thoracoscopic lobectomy was longer than that of the three-port thoracoscopic lobectomy (P < 0.001). There was no statistical difference between the two groups in the intraoperative conversion to thoracotomy and the number of lymph node dissections (P > 0.05). Postoperative pain stress indices and complication rates of the experimental group were significantly lower than those of the control group (P < 0.001).

Conclusion

Single-port thoracoscopic lobectomy can improve the perioperative indices of lung cancer patients, reduce their pain stress response, and accelerate postoperative recovery. However, its operation is difficult and time-consuming, requiring experienced surgeons for improved surgical outcomes in practice.