Genetic alterations and protein expression in combined small cell lung cancers and small cell lung cancers arising from lung adenocarcinomas after therapy with tyrosine kinase inhibitors

Characteristics and prognosis of EGFR mutations in small cell lung cancer patients in the NGS era

PURPOSE

Targeted therapy has not been effective for small cell lung cancer (SCLC) patients. Although some studies have reported on EGFR mutations in SCLC, a systematic investigation into the clinical, immunohistochemical, and molecular characteristics and prognosis of EGFR-mutated SCLCs is lacking.

METHODS

Fifty-seven SCLC patients underwent next-generation sequencing technology, with 11 in having EGFR mutations (group A) and 46 without (group B). Immunohistochemistry markers were assessed, and the clinical features and first-line treatment outcomes of both groups were analyzed.

RESULTS

Group A consisted primarily of non-smokers (63.6%), females (54.5%), and peripheral-type tumors (54.5%), while group B mainly comprised heavy smokers (71.7%), males (84.8%), and central-type tumors (67.4%). Both groups showed similar immunohistochemistry results and had RB1 and TP53 mutations. When treated with tyrosine kinase inhibitors (TKIs) plus chemotherapy, group A had a higher treatment response rate with overall response and disease control rates of 80% and 100%, respectively, compared to 57.1% and 100% in group B. Group A also had a significantly longer median progression-free survival (8.20 months, 95% CI 6.91-9.49 months) than group B (2.97 months, 95% CI 2.79-3.15), with a significant difference (P = 0.043). Additionally, the median overall survival was significantly longer in group A (16.70 months, 95% CI 1.20-32.21) than in group B (7.37 months, 95% CI 3.85-10.89) (P = 0.016).

CONCLUSION

EGFR-mutated SCLCs occurred more frequently in non-smoking females and were linked to prolonged survival, implying a positive prognostic impact. These SCLCs shared immunohistochemical similarities with conventional SCLCs, and both types had prevalent RB1 and TP53 mutations.

Exploring the molecular features and genetic prognostic factors of pulmonary high-grade neuroendocrine carcinomas

Molecular research on large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) has progressed significantly. However, there are still fewer molecular markers related to prognostic/therapeutic strategies for these conditions compared to those for adenocarcinoma. We therefore investigated the molecular characteristics of neuroendocrine carcinomas (NECs). We enrolled patients surgically diagnosed with NECs between 2011 and 2019, with complete follow-up records. All were analyzed using whole exome sequencing and p53/Rb immunohistochemistry (IHC). A total of 92 cases, comprising 45 pure SCLC, 15 combined SCLC, 27 pure LCNEC, and 5 combined LCNEC, were included. TP53 (78.3%) and RB1 (34.8%) were the most common molecular alterations, followed by KMT2D, LRP1B, FAT3, NCOR2, SPTA1, and NOTCH1. The mutation frequency for EGFR was 10.9%. Sixteen patients with LCNEC who had TP53/RB1 co-alterations were SCLC-like, while the remaining were NSCLC-like. There was no statistically significant difference between the groups regarding overall survival (OS; p = 0.458) and progression-free survival (PFS; p = 0.157). The frequency of the loss of Rb expression by IHC in SCLC-like LCNEC was 100%. Significant pathway alterations unique to SCLC included Notch and AMPK, while HIF-1 was enriched exclusively in LCNEC. NCOR2 mutation was linked to worse OS (p = 0.029) and PFS (p = 0.015), while wild-type SPTA1 was associated with poor PFS (p = 0.018). IHC for Rb was reliable for predicting LCNEC molecular subtypes, indicating its clinical value. NCOR2 and SPTA1 alterations were identified as prognostic factors that may provide therapeutic targets for patients with NEC.

[Two Cases of TKI-resistant Small Cell Lung Cancer Transformation in Advanced Adenocarcinoma and Literature Review]

Treatment of advanced non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) can achieve good disease control, but it will inevitably produce drug resistance. About 3%-10% of the resistance mechanism is small cell transformation. Two cases of stage IV lung adenocarcinoma with EGFR mutation were reported and the disease was controlled after EGFR-TKIs treatment. In case 1, progression-free survival (PFS) before small cell carcinoma transformation was 16 months, and in case 2, PFS before small cell carcinoma transformation was 24 months. Subsequent biopsy after disease progression indicated a shift to small cell lung cancer. Case 1 PFS after small cell carcinoma transformation was 6 months, and case 2 PFS after small cell carcinoma transformation was 8 months, and overall survival (OS) was 36 months, which significantly prolonged the patient's survival. At the same time, the literature of such drug resistance mutations was reviewed. For patients with advanced NSCLC with sensitive mutations, it is necessary to conduct secondary histopathological tests after TKIs treatment resistance, and select subsequent treatment according to different resistance mechanisms for the whole course of disease management.
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Outcomes in Patients With Lung Adenocarcinoma With Transformation to Small Cell Lung Cancer After EGFR Tyrosine Kinase Inhibitors Resistance: A Systematic Review and Pooled Analysis

Background

Lung adenocarcinoma can transform into small-cell lung cancer (SCLC) when resistance to tyrosine kinase inhibitors (TKIs) develops. Approximately 3% to 10% of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) could transform to SCLC. This phenomenon has been described in several case reports and small patient series. However, the characteristics and treatment outcomes of this population have not been comprehensively reported, and their clinical course is poorly characterized.

Methods

We performed a systematic review of the published literature to summarize the clinical and pathological features and prognosis of the reported cases and analyzed the demographics, disease features, and outcomes.

Results

A total of 72 patients (50 females and 22 males) initially diagnosed with lung adenocarcinoma were included. EGFR mutations included 19-deletion (75%), L858R (22%), and G719X (3%). All patients received EGFR-TKIs before SCLC transformation. The median time from diagnosis to transformation was 20.5 months (95% CI, 15.45 to 26.55 months). Of the 67 patients with post-translational gene test results, 58 maintained their EGFR mutation, and only 1 of 18 with prior T790M positivity retained T790M mutation. After the pathological transformation, both conventional chemotherapy regimen and chemotherapy combined targeted therapy yielded high response rates. The disease control rate of first-line therapy after transformation was 76%, while the objective response rate was 48%. The median overall survival (OS) since diagnosis was 27 months (95% CI, 22.90 to 31.10 months), whereas median OS since SCLC transformation was 8.5 months (95% CI, 5.50 to 11.60 months).

Conclusion

The prognosis of transformed SCLC is worse than primary SCLC. The response rate to conventional chemotherapy was high. However, the progression-free survival and OS after transformation were short and the prognosis was poor with first-line therapies. New therapies are needed in the management of transformed SCLC.

Clinicopathological features of patients with transformation from EGFR mutant lung adenocarcinoma to small cell lung cancer

Background

Recently, an increasing number of cases with transformation from lung adenocarcinoma to small cell lung cancer (SCLC) have been identified, but few studies have investigated the clinical, pathological as well as molecular characteristics of these cases. This study aimed to summarize and analyze these features.

Methods

We retrospectively collected data including clinical information, laboratory examination results, radiological and pathological findings of ten patients, who were confirmed to undergo SCLC transformation following treatment from January 2014 to January 2020.

Results

The median time of treatment (targeted agents) was 14 months, and the median time interval of SCLC transformation following treatment was 24 months. Immunohistochemical indicators after transformation showed positive thyroid transcription factor 1 (TTF1), synaptophysin (Syn), CD56, and AE1/AE3, highly expressed Ki67, as well as negative programmed cell death-ligand 1 (PD-L1). Compared with the patients who received targeted therapy first, those patients who received chemotherapy followed by targeted therapy presented longer time intervals to transformation (36 vs. 22 months). Genetic testing after transformation showed that eight patients still maintained the original epidermal growth factor receptor (EGFR) mutation types. The median progression-free survival (PFS) after transformation was 5 months, and the median survival time after transformation was 10 months in seven patients who died.

Conclusions

Lung adenocarcinomas, once transformed to SCLC, progress rapidly and lead to poorer prognosis. After transformation, most of the patients maintain the original EGFR mutation types.

[MDT Treatment of Small Cell Lung Cancer Complicated with Adenocarcinoma: A Case Report and Literature Review]

Small cell lung cancer (SCLC) is the most malignant lung cancer with the highest mortality. At present, the first-line standard treatment is still based on Etoposide and Platinum chemotherapy. However, for SCLC that progresses after first-line therapy, the treatment options are still very limited. Since the molecular mechanism of first-line drug resistance of SCLC is still unclear, and the precision medicine strategy after first-line drug resistance is still in the pre-clinical stage. The proportion of secondary biopsy and genetic testing is very low after the progress of first-line treatment of SCLC. In this study, we report a case of a middle-aged woman who was first diagnosed with SCLC. Adenocarcinoma with sensitive gene mutations and repeated changes of small cell carcinoma were detected by multiple biopsies during the course of the disease, suggesting that the patient may be a special subtype of SCLC - mixed SCLC (M-SCLC). In this case, the patient has been treated with radiotherapy and chemotherapy, immunotherapy and targeted therapy successively, and the survival time has reached 2 years and 8 months. Through the case report and literature review retrospectively, this study aimed to explore the part patients may start to present hybrid histopathologic types or tissue type change after treatment of SCLC. Biopsy pathologic histology and genetic testing is necessary after disease progression to look for potential therapeutic targets, so as to give precise treatment based on molecular markers detection results and provide the patient with the benefit of survival for as long as possible.
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Liquid biopsy as an option for predictive testing and prognosis in patients with lung cancer

BACKGROUND

The aim of this study was to investigate the clinical value of liquid biopsy as a primary source for variant analysis in lung cancer. In addition, we sought to characterize liquid biopsy variants and to correlate mutational load to clinical data.

METHODS

Circulating cell-free DNA was extracted from plasma from patients with lung cancer (n = 60) and controls with benign lung disease (n = 16). Variant analysis was performed using the AVENIO ctDNA Surveillance kit and the results were correlated to clinical and variant analysis data from tumor tissue or cytology retrieved from clinical routine diagnostics.

RESULTS

There were significantly more variants detected in lung cancer cases compared to controls (p = 0.011), but no difference between the histological subgroups of lung cancer was found (p = 0.465). Furthermore, significantly more variants were detected in patients with stage IIIb-IV disease compared to patients with stage I-IIIa (median 7 vs 4, p = 0.017). Plasma cfDNA mutational load was significantly associated with overall survival (p = 0.010). The association persisted when adjusted for stage and ECOG performance status (HR: 3.64, 95% CI 1.37-9.67, p = 0.009). Agreement between tumor and plasma samples significantly differed with stage; patients with stage IIIb-IV disease showed agreement in 88.2% of the cases with clinically relevant variants, compared to zero cases in stage I-IIIa (p = 0.004). Furthermore, one variant in EGFR, two in KRAS, and one in BRAF were detected in plasma but not in tumor samples.

CONCLUSION

This study concludes that in the vast majority of advanced NSCLC patients a reliable variant analysis can be performed using liquid biopsy from plasma. Furthermore, we found that the number of variants in plasma is associated with prognosis, possibly indicating a strategy for closer follow up on this crucial patient group.

Combined small cell lung carcinoma harboring ALK rearrangement: A case report and literature review

Combined small cell lung cancer (c‐SCLC) is a relatively rare subtype of SCLC and is defined by the combination of SCLC and any elements of non‐small cell carcinoma (NSCLC). Standard chemotherapy for patients with c‐SCLC has not yet been established. Gene mutations such as epidermal growth factor receptor (EGFR) mutations may be detected in patients with c‐SCLC. However, little is known about anaplastic lymphoma kinase (ALK) rearrangement in c‐SCLC patients. Here, we report a young female patient who was successfully treated with alectinib for ALK‐positive c‐SCLC after failure of immunochemotherapy for SCLC and cytotoxic chemotherapy for adenocarcinoma. Moreover, we performed a literature review of EGFR‐ or ALK‐positive c‐SCLC patients. Our report suggests that ALK testing may be justified in patients with SCLC that contain an adenocarcinoma component.

Key points

Significant findings of the study

• This is the first report describing the treatment course comprising immunochemotherapy and ALK‐TKI in a patient with c‐SCLC harboring ALK rearrangement.

What this study adds

• Our case and literature review suggest that although ALK mutation is rare in patients with c‐SCLC, its identification and treatment with ALK‐TKIs may contribute to clinical benefits.

Dynamic changes of acquired T790M mutation and small cell lung cancer transformation in a patient with EGFR-mutant adenocarcinoma after first- and third-generation EGFR-TKIs: a case report

Epithelial growth factor receptor (EGFR) T790M mutation and small cell lung cancer (SCLC) transformation are well-known resistance mechanisms acquired during treatment with EGFR tyrosine kinase inhibitors (TKIs). Various mechanisms sometimes coexist in patients. Here, we report a 57-year-old female diagnosed with stage IV lung adenocarcinoma, who harbored an EGFR exon 19 deletion mutation. This patient initially received gefitinib and progressed after 14 months. A repeat biopsy was performed, and the original EGFR exon 19 deletion and acquired exon 20 T790M mutation were identified. Then, pemetrexed plus carboplatin was administered as second-line and osimertinib as third-line treatment. Rapid progression and mixed response were observed after 2 months on osimertinib, with stable disease of the primary lung lesion but rapid growth of a right lower chest mass. The progressive chest lesion underwent biopsy, and the SCLC transformation was revealed. Furthermore, the patient was treated with etoposide and cisplatin, and she achieved disease control for 4 months. A fourth biopsy both for the primary lung lesion and the chest mass were finally conducted. Interestingly, the histopathology of the two different lesions showed adenocarcinoma and SCLC, respectively. The patient then rapidly suffered brain metastasis, and no EGFR mutations were detected in her cerebrospinal fluid (CSF). Overall survival (OS) of the patient was 29 months. This patient experienced concomitant resistance mechanisms of T790M mutation and SCLC transformation, which might have resulted from intra-tumor heterogeneity and drug-induced selection. Ultimately, this case reminds us that repeat biopsies are essential for patients receiving EGFR-TKIs in order to make appropriate treatment decisions according to the diverse mechanisms of acquired resistance.

Intrinsic resistance to EGFR-Tyrosine Kinase Inhibitors in EGFR-Mutant Non-Small Cell Lung Cancer: Differences and Similarities with Acquired Resistance

Activating mutations in the epidermal growth factor receptor gene occur as early cancer-driving clonal events in a subset of patients with non-small cell lung cancer (NSCLC) and result in increased sensitivity to EGFR-tyrosine-kinase-inhibitors (EGFR-TKIs). Despite very frequent and often prolonged clinical response to EGFR-TKIs, virtually all advanced EGFR-mutated (EGFRM+) NSCLCs inevitably acquire resistance mechanisms and progress at some point during treatment. Additionally, 20-30% of patients do not respond or respond for a very short time (<3 months) because of intrinsic resistance. While several mechanisms of acquired EGFR-TKI-resistance have been determined by analyzing tumor specimens obtained at disease progression, the factors causing intrinsic TKI-resistance are less understood. However, recent comprehensive molecular-pathological profiling of advanced EGFRM+ NSCLC at baseline has illustrated the co-existence of multiple genetic, phenotypic, and functional mechanisms that may contribute to tumor progression and cause intrinsic TKI-resistance. Several of these mechanisms have been further corroborated by preclinical experiments. Intrinsic resistance can be caused by mechanisms inherent in EGFR or by EGFR-independent processes, including genetic, phenotypic or functional tumor changes. This comprehensive review describes the identified mechanisms connected with intrinsic EGFR-TKI-resistance and differences and similarities with acquired resistance and among clinically implemented EGFR-TKIs of different generations. Additionally, the review highlights the need for extensive pre-treatment molecular profiling of advanced NSCLC for identifying inherently TKI-resistant cases and designing potential combinatorial targeted strategies to treat them.

Small cell lung cancer transformation from EGFR-mutated lung adenocarcinoma: A case report and literatures review

Epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have markedly improved the response of non-small cell lung cancer (NSCLC) with EGFR-mutant patients. However, these patients inevitably come cross acquired resistance to EGFR-TKIs. The transformation of lung adenocarcinoma to small cell lung cancer (SCLC) following treatment with EGFR-TKIs is rare, which leads to resistance to EGFR-TKIs. The present case concerns a case of a 38-year-old man presenting with cough and dyspnea. Radical resection was performed and confirmed an EGFR exon 21 L858R lung adenocarcinoma. However, the patient suffered pleural metastasis after successful treatment with surgery and adjuvant treatment. So, erlotinib was administered with 18 months. Because of enlarged pleural nodule, repeat biopsy identified an SCLC and chemotherapy was started. However, despite the brief success of chemotherapy, our patient suffered brain metastasis. Our case emaphsizes both the profile of transformation from NSCLC to SCLC and the importance of repeat biopsy dealing with drug resistance. We also summarize the clinical characteristics, mechanisms, predictors of SCLC transformation, treatment after transformation and other types of transformation to SCLC.

The expression of S100B protein in serum of patients with brain metastases from small-cell lung cancer and its clinical significance

The objective of the present study was to investigate the expression of S100B protein in serum of patients with brain metastases from small cell lung cancer (SCLC), and its clinical significance. A total of 138 patients with SCLC were selected from June 2013 to December 2015. Simultaneously, 138 healthy adult volunteers (healthy controls) were selected in the medical examination center of People's Hospital of Rizhao. Among the 138 patients with SCLC, 48 had liver metastases and 44 had brain metastases. Of the remaining 46 patients, 20 were initially diagnosed with SCLC and 26 underwent surgery and postoperative chemotherapy. The levels of serum S100B in patients and healthy controls were measured by ELISA, and analyzed by SPSS 20.0 statistical software. The serum S100B protein levels in patients with SCLC were significantly higher than those in healthy controls (p<0.05). Among the subgroups of patients with SCLC, the levels of serum S100B in patients with brain metastases were significantly higher than in the other subgroups (p<0.05). No significant differences were found between the other subgroups, except for the brain metastases group. We found that serum S100B protein expression levels were significantly reduced in patients with brain metastases after cobalt-60 radiotherapy (p<0.05). During follow-up, we found that higher expression of S100B protein was usually associated with poorer prognosis, higher mortality rate at 1 year, and lower survival rate. In conclusion, S100B protein can serve as a serological marker for brain metastases from SCLC, which provides important theoretical support for early detection of brain metastases.