Molecular Pathology of Pulmonary Large Cell Neuroendocrine Carcinoma: Novel Concepts and Treatments

Clinical characteristics and treatment management of combined large cell neuroendocrine carcinoma, a subtype of large cell neuroendocrine carcinoma

Combined large cell neuroendocrine carcinoma (CLCNEC) is a rare neuroendocrine carcinoma, accounting for approximately 10% of large cell neuroendocrine carcinoma (LCNEC). Mainly composed of coexisting adenocarcinoma components, with strong invasiveness and poor prognosis. The treatment regimen for CLCNEC mainly refers to complete surgical resection as the first choice in the early stage, while patients with stage II or higher require adjuvant treatment. At present, research on CLCNEC is mostly small sample and retrospective, and there is no consensus on whether molecular typing and treatment should be carried out. There is considerable controversy over whether it should be managed as small-cell lung cancer (SCLC) or non-small-cell lung cancer (NSCLC). Therefore, in order to solve the problem of confusion in the selection of treatment regimens for CLCNEC, while also considering the therapeutic effects, this article summarizes and analyzes previous studies, fully seeks evidence, and boldly proposes new therapeutic insights: the etoposide-platinum (EP) regimen serves as the basis for adjuvant therapy; In addition, SCLC/NSCLC-CLCNEC can be distinguished based on presence of RB1 and TP53 co-mutation, and targeted therapy or NSCLC type chemotherapy including platinum + gemcitabine or taxanes (NSCLC-GEM/TAX) can be used in combination or sequentially for NSCLC-CLCNEC.

Mutational analysis of pulmonary large cell neuroendocrine carcinoma: APC gene mutations identify a good prognostic factor

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a highly aggressive neoplasm with biological heterogeneity. Mutations in multiple genes have been identified in LCNEC. However, associations between gene alterations, histopathological characteristics, and prognosis remain ambiguous. Here, we investigated the clinicopathologic, immunohistochemical, and genomic characteristics of 19 patients with LCNEC and 9 patients with atypical carcinoid (AC). We revealed high mutation frequencies of TP53 (89.5 %), RB1 (42.1 %), APC (31.6 %), and MCL1 (31.6 %) in LCNEC, while genetic alterations were rarely found in AC. APC alterations mainly occurred to the exon 16 and were only identified in LCNEC with wild-type RB1. The 19 LCNEC were further subgrouped into APC wild-type (LCNEC-APCMT, 6/19) and APC-mutated (LCNEC-APCWT, 13/19) subgroups. In comparison with LCNEC-APCWT, LCNEC-APCMT displayed lower TMB (median: 12.64 vs 4.20, P = 0.045), and relatively mild cytologic atypia. In addition, LCNEC-APCMT distinguished itself from AC and LCNEC-APCWT by obviously downregulated expression of neuroendocrine markers (CD56 and Syn, P < 0.01) and significantly altered expression of genes downstream of APC (β-catenin migrating into the cytoplasm and nucleus, P < 0.001; c-Myc upregulating, P = 0.005). The OS of LCNEC-APCMT was numerically intermediate between AC and LCNEC-APCWT. We first proposed that APC alterations were common in LCNEC with wild-type RB1 and that LCNEC-APCMT was associated with lower TMB and better OS in comparison with LCNEC-APCWT.

Prognostic scores in pulmonary large cell neuroendocrine carcinoma: A retrospective cohort study

Introduction

Pulmonary large cell neuroendocrine carcinoma (PLCNEC) is a rare but aggressive subtype of lung cancer with an incidence of approximately 3 %. Identifying effective prognostic indicators is crucial for guiding treatments. This study examined the relationship between inflammatory markers and PLCNEC patient overall survival (OS) and sought to determine their prognostic significance in PLCNEC.

Methods

Patients diagnosed with PLCNEC between 2007 and 2022 at the oncology center, were retrospectively included. Patients who underwent surgery were pathologically re-staged post-surgery. Potential prognostic parameters (neutrophil/lymphocyte ratio, platelet/lymphocyte ratio [PLR], panimmune inflammatory value, prognostic nutritional index and modified Glasgow prognostic score [mGPS]) were calculated at that time of diagnosis.

Results

Sixty patients were included. The median follow-up was 23 months. Thirty-eight patients initially diagnosed with early or locally advanced. The mGPS was identified as a poor prognostic factor that influenced disease free survival (DFS) fourfold (p = 0.03). All patients' median OS was 45 months. Evaluating factors affecting OS in all patients, statistically significant relationships were observed between OS and the prognostic nutritional index (p = 0.001), neutrophil/lymphocyte ratio (p = 0.03), platelet/lymphocyte ratio (p = 0.002), and pan-immunoinflammatory value (p = 0.005). Upon multivariate analysis, the platelet/lymphocyte ratio was identified as an independent poor prognostic factor for OS, increasing the mortality risk by 5.4 times (p = 0.002).

Conclusion

mGPS was significantly linked with prognosis in non-metastatic PLCNEC, with patients with higher mGPS exhibiting poorer long-term DFS. This finding contributes to the evolving understanding of PLCNEC. The multivariable predictive model we employed suggests that PLR is an independent predictor of OS at all stages. A lower PLR was correlated with worse overall survival. Thus, PLR can be a readily accessible and cost-effective prognostic factor in PLCNEC patients.

The outcomes of different regimens depend on the molecular subtypes of pulmonary large-cell neuroendocrine carcinoma: A retrospective study in China

BACKGROUND

The optimal systemic treatment for pulmonary large-cell neuroendocrine carcinoma (LCNEC) remains controversial, and recent advances in LCNEC molecular subtype classification have provided potential strategies for assisting in treatment decisions. Our study aimed to investigate the impact of treatment regimens, molecular subtypes and their concordance on clinical outcomes of patients diagnosed with LCNEC.

PATIENTS AND METHODS

All patients diagnosed with advanced pulmonary LCNEC in Peking Union Medical College Hospital (PUMCH) between January 2000 and October 2021 were enrolled in this retrospective study. The tumor samples were collected and sequenced using a tumor-specific gene panel, while clinical information was retrieved from the medical records system. The survival and therapeutic response were analyzed and compared between different subgroups classified by treatment regimen (SCLC or NSCLC-based), molecular subtype (type I or II) or the combination.

RESULTS

In univariate subgroup analysis categorized only by treatment regimen or molecular subtype, there were no differences identified in DCR, ORR, PFS, or OS. Nevertheless, the group with consistent treatment regimen and molecular subtype exhibited significantly longer OS than that of the inconsistent group (median OS 37.7 vs. 8.3 months; p = 0.046). Particularly, the OS of patients with type II LCNEC treated with SCLC-based regimen was significantly prolonged than that of others (median 37.7 vs. 10.5 months; p = 0.039).

CONCLUSIONS

Collectively, our study revealed the clinical outcomes of different treatment regimens for LCNEC patients highly depend on their molecular subtypes, highlighting the need for sequencing-guided therapy.

Clinical activity of pembrolizumab with or without chemotherapy in advanced pulmonary large-cell and large-cell neuroendocrine carcinomas: a multicenter retrospective cohort study

BACKGROUND

Immune checkpoint inhibitors (ICI)-based combination strategies have improved the survival outcomes in advanced non-small cell lung cancers; however, data regarding their efficacy remains limited for uncommon histological types, including large-cell carcinoma (LCC) and large-cell neuroendocrine carcinoma (LCNEC).

METHODS

We retrospectively analyzed a total of 60 patients with advanced LCC and LCNEC - 37 treatment-naïve and 23 pre-treated - who received pembrolizumab with or without chemotherapy. Treatment and survival outcomes were analyzed.

RESULTS

Of the 37 treatment-naïve patients who received first-line pembrolizumab combined with chemotherapy, the 27 patients with LCC had an overall response rate (ORR) of 44.4% (12/27) and a disease control rate (DCR) of 88.9% (24/27); whereas 10 patients with LCNEC had an ORR of 70% (7/10) and DCR of 90% (9/10). The median progression-free survival (mPFS) was 7.0 months (95% confidence intervals [CI]: 2.2-11.8) and median overall survival (mOS) was 24.0 months (95%CI: 0.0-50.1) for first-line pembrolizumab plus chemotherapy of LCC (n = 27), whereas mPFS was 5.5 months (95%CI: 2.3-8.7) and mOS was 13.0 months (95%CI: 11.0-15.0) for first-line pembrolizumab plus chemotherapy of LCNEC (n = 10). Of the 23 pre-treated patients who received subsequent-line pembrolizumab with or without chemotherapy, mPFS was 2.0 months (95% CI: 0.6-3.4) and mOS was 4.5 months (95% CI: 0.0-9.0) for LCC and mPFS was 3.8 months (95% CI: 0.0-7.6) and mOS was not reached for LCNEC.

CONCLUSION

Our study provides real-world clinical evidence of the anti-tumor activity of pembrolizumab plus chemotherapy in advanced LCC and LCNEC, indicating that this regimen could serve as a treatment option, particularly as first-line therapy, for improving the survival outcomes of patients with these rare histological subtypes of lung cancer.

TRIAL REGISTRATION

NCT05023837(ESPORTA, 27/08/2021).

The Surgical Management of Lung Neuroendocrine Neoplasms

This review summarizes key recent developments relevant to the surgical management of lung neuroendocrine neoplasms (L-NENs), including typical and atypical carcinoids, large cell neuroendocrine carcinoma, and small cell lung carcinoma. This review includes recent insights into the classification, clinical presentation, diagnostic workup, treatment options, and follow-up. Highlighted topics include general principles of surgery in localized or locally advanced or metastatic L-NENs, lung-sparing surgery for small, peripheral typical carcinoids, adjuvant and systemic therapies for typical and atypical carcinoids, and surgery and adjuvant therapies for large cell neuroendocrine carcinoma and small cell lung carcinoma.

Differential response in patients with large cell neuroendocrine carcinoma of the lung to initial therapy: A case series

BACKGROUND

Large cell neuroendocrine tumors of the lung (LCNEC) are rare. Chemotherapy with the small cell lung carcinoma (SCLC) regimen is the most appropriate treatment for LCNEC. However, there is evidence that the non-small cell lung cancer regimen is also effective in some reported cases. Due to the differences in response to LCNEC treatment, a standard of care for LCNEC has not been established.

CASES

The clinical records of nine patients with LCNEC who were treated with anticancer drugs based on an SCLC regimen from March 2016 to March 2022 were retrospectively reviewed. The patients who responded to treatment after one cycle of systemic chemotherapy were compared to those who did not respond. All patients in the responder group had a performance status (PS) of 0 or 1. However, 5 of the 6 patients in the non-responder group had a PS of 2 or 3, indicating that many patients were in poor general condition. Although patients with multiple metastases to more than one organ prior to treatment were not identified in the responder group, five of these patients were in the non-responder group. In the non-responder group, all patients discontinued treatment due to deterioration of general condition during first-line treatment. Thus, none of them were able to start the second-line treatment.

CONCLUSION

The results of this study may suggest that early diagnosis and initiation of treatment before multiple organ metastasis development and PS decline may have clinical implications that could lead to improved treatment response in patients with LCNEC.

Pulmonary Large Cell Neuroendocrine Carcinoma

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare subtype of malignant pulmonary tumor. The incidence rate of LCNEC was reported to be 0.3%–3% in lung cancers. Although LCNEC is classified as non-small cell lung cancer (NSCLC), it is more aggressive and malignant than other NSCLC, and its biological behavior is similar to that of small cell lung cancer (SCLC). Most of the LCNEC patients are elderly smoking male and the clinical manifestations are not specific. The imaging manifestations of the tumors are often located in the periphery and the upper lobes, and the enlargement of mediastinal or hilar lymph nodes is common. The diagnosis is mainly based on pathology by the histological features and immunohistochemistry (IHC). Specific neuroendocrine markers such as chromogranin A (CgA), synaptophysin (Syn) and CD56 are usually diffusely positive in LCNEC, and found that insulinoma-associated protein (INSM1) and high rate of Ki-67 are helpful for diagnosis. More differential diagnoses also increase the difficulty of correctly diagnosing LCNEC. The rise of LCNEC molecular typing in recent years may be helpful for diagnosis and subsequent treatment. This review focuses on the epidemiological features, imaging studies, pathology, diagnosis, treatment, and prognosis of LCNEC.

Classifying Pulmonary and Urinary High-grade Neuroendocrine Carcinoma by CK7 Immunohistochemistry

High-grade neuroendocrine carcinoma (HGNEC) is subclassified into small cell carcinoma (SmCC) and large cell neuroendocrine carcinoma (LCNEC). Although both are clinically aggressive, the SmCC and LCNEC need to have different treatment strategies, and accurate pathologic diagnosis is challenging. We studied a large retrospective cohort (186 cases) of HGNEC of bladder and lung to investigate the abundance of cytokeratin (CK) 7 expression and staining pattern in SmCC and LCNEC. Overall, the pulmonary and urinary HGNEC exhibited several different CK7 staining patterns, including negative staining (n=28), dot-like staining (n=73), partial membranous staining (n=26), and complete membranous staining (n=60). Overall, 88.9% (44/49) of pulmonary SmCC and 88.0% (44/50) of urinary SmCC showed negative or dot-like patterns for CK7, while 90.8% (59/65) of pulmonary LCNEC and 72.7% (16/22) of urinary LCNEC showed partial or complete membranous patterns for CK7 (χ 2 =105.05, P <0.0001). The distinct staining patterns were also present in those mixed SmCC and LCNEC. In addition, the specimen types or fixation did not affect CK7 staining patterns. In conclusion, CK7 has a high differential value for SmCC and LCNEC and could help guide personalized treatment for patients.

Large Cell Neuroendocrine Carcinoma of the Lung: Current Understanding and Challenges

Large cell neuroendocrine carcinoma of the lung (LCNEC) is a rare and highly aggressive type of lung cancer, with a complex biology that shares similarities with both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). The prognosis of LCNEC is poor, with a median overall survival of 8-12 months. The diagnosis of LCNEC requires the identification of neuroendocrine morphology and the expression of at least one of the neuroendocrine markers (chromogranin A, synaptophysin or CD56). In the last few years, the introduction of next-generation sequencing allowed the identification of molecular subtypes of LCNEC, with prognostic and potential therapeutic implications: one subtype is similar to SCLC (SCLC-like), while the other is similar to NSCLC (NSCLC-like). Because of LCNEC rarity, most evidence comes from small retrospective studies and treatment strategies that are extrapolated from those adopted in patients with SCLC and NSCLC. Nevertheless, limited but promising data about targeted therapies and immune checkpoint inhibitors in patients with LCNEC are emerging. LCNEC clinical management is still controversial and standardized treatment strategies are currently lacking. The aim of this manuscript is to review clinical and molecular data about LCNEC to better understand the optimal management and the potential prognostic and therapeutic implications of molecular subtypes.

Combined large cell neuroendocrine carcinoma of the lung associated with low-grade fetal adenocarcinoma without β-catenin mutation: a case report

We report a case of combined large cell neuroendocrine carcinoma of the lung associated with low-grade fetal adenocarcinoma (L-FLAC) without β-catenin mutation in exon 3. A 33-year-old man presented at the hospital with a more than 5-month history of cough with no obvious cause. Computed tomography revealed a large, solid, round mass located in the upper lobe of the right lung. Microscopic examination showed two tumor components: large cell neuroendocrine carcinoma and low-grade fetal adenocarcinoma. Immunohistochemistry ofthe fetal adenocarcinoma showed abnormal nuclear/cytoplasmic expression of β-catenin, but no exon 3 mutation in β-catenin. Our findings provide further insight into the pathologic mechanism of FLAC.