Tackling the current dilemma of immunotherapy in extensive-stage small cell lung cancer: A promising strategy of combining with radiotherapy

Dynamic evolution and antitumor mechanisms of CXCR6+CD8+ T cells in small cell lung cancer treated with low-dose radiotherapy and immunotherapy

BACKGROUND

Patients with small-cell lung cancer (SCLC) have the poor prognosis. Current research suggested that low-dose radiotherapy (LDRT) combined with immunotherapy can enhance the immunogenicity of tumor cells, thereby improving antigen presentation and promoting the intratumoral infiltration of CD8+ T cells, which significantly extends the survival of patients. However, the change trajectory of T cells, and the mechanisms underlying the promotion of intratumoral infiltration of CD8+ T cells, and the enhancement of their cytotoxic functions remain to be elucidated.

METHODS

To delineate the dynamic changes of T cells, we collected tumors from Kaede tumor-bearing mice that had undergone radioimmunotherapy. Using flow cytometry, we sorted intratumoral-infiltrating immune cells, which were required for single-cell RNA sequencing, at various time points (Kaede Red: derived from tumor-draining lymph node [TDLN]). The results obtained from the sequencing analysis were further validated through experiments, such as flow cytometry, immunofluorescence, and analysis of clinical cohort data.

RESULTS

Here, we observed stem-like T cells migrating from the TDLN to the tumor site and differentiating into effector phenotypes within the tumor. Dendritic cells (DCs) are the key cluster that induces the differentiation of stem-like T cell into effector phenotypes. Moreover, SCLC patients with a high infiltration of tumor-specific CXCR6+CD8+ T cells exhibited a supportive TME and longer survival time (P < 0.001).

CONCLUSIONS

This study delineates the change trajectory of CD8+ T cells, identifies the crucial role of DCs in T cell differentiation, and highlights the significance of tumor-specific CXCR6+CD8+ T cells in anti-tumor immunity. Future therapeutic strategies for SCLC could focus on enhancing the infiltration of activated DCs and CXCR6+CD8+ T cells within the tumor microenvironment to improve treatment efficacy.

Thyroxine alleviates interstitial lung disease induced by combined radiotherapy and immunotherapy

Immune checkpoint blockade (ICB) combined with radiotherapy (RT) has improved patients survival, but also increased the risk of pulmonary adverse effects (AEs). Therefore, to explore potential drug targets for interstitial lung disease (ILD). We investigated the interaction of ICB and RT in pulmonary AEs using the disproportionality analysis and COX regression. Genome-wide association studies, transcriptome analysis, and vivo models highlighted the role of programmed death-ligand-1 (PD-L1) in ILD. Mendelian randomization analysis identified drug targets. Clinical data on pulmonary AEs in patients with non-small cell lung cancer (NSCLC) were used to validate the finding. Herein, we confirmed ICB combined with RT posed the highest risk of pulmonary AEs, with reporting odds ratio of interaction effect was 3.727. Anti-PD-L1 posed a greater risk of pulmonary AEs compared to anti-PD-1 (Hazard Ratio = 9.355) or anti-cytotoxic lymphocyte antigen-4 (CTLA-4) (Hazard Ratio = 6.985). In vivo study, PD-L1 expression in radiation induced lung injury negatively correlated with collagen deposition. Notably, thyroid hormone receptors were identified as drug targets for ILD. Our results demonstrate that thyroxine exerts a significant inhibitory effect on pulmonary fibrosis progression. Clinical evidence robustly supports the correlation between thyroid function and ILD. These findings highlight the importance of PD-L1 and thyroxine in understanding and managing ILD.

Both complete response and long-term survival after combination therapy with toripalimab in a patient with meta-oligometastases cervical cancer: a case report

Background

The therapeutic landscape for recurrent or metastatic cervical cancer remains limited, with few options available. According to National Comprehensive Cancer Network (NCCN) guidelines, pembrolizumab combined with chemotherapy, with or without bevacizumab, is recommended for affected patients. Despite these guidelines, recurrence rates remain elevated, and survival outcomes following standard interventions are unsatisfactory. Furthermore, real-world management of recurrent or metastatic cervical cancer presents inherent complexities, often requiring an integrative, multidimensional treatment approach to enhance long-term survival. The pressing need to refine and adopt multimodal therapeutic strategies is evident in addressing the persistent challenges associated with disease recurrence and progression.

Case description

The case involved a 40-year-old female diagnosed with advanced cervical cancer who underwent radical hysterectomy. Postoperative pathology identified high-risk features, including lymph node involvement, necessitating adjuvant chemoradiotherapy. However, disease progression occurred during treatment, manifesting as metastases in the left supraclavicular and axillary lymph nodes. Subsequent local radiotherapy and systemic therapy led to a favorable response. By November 2024, overall survival (OS) had surpassed 72 months, with toripalimab administered for 65 months, during which no immunotherapy-related adverse events occurred.

Conclusion

This case offers clinical insight into the efficacy and safety of integrating chemotherapy, immunotherapy, and radiotherapy in recurrent or metastatic cervical cancer. The multimodal approach contributes to prolonged survival in this patient. Further clinical trials are essential to substantiate the therapeutic benefits of this regimen in broader patient cohorts.

Unraveling the NLRP family: Structure, function, activation, critical influence on tumor progression, and potential as targets for cancer therapy

The innate immune system serves as the body's initial defense, swiftly detecting danger via pattern recognition receptors (PRRs). Among these, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing proteins (NLRPs) are pivotal in recognizing pathogen-associated and damage-associated molecular patterns, thereby triggering immune responses. NLRPs, the most extensively studied subset within the NLR family, form inflammasomes that regulate inflammation, essential for innate immunity activation. Recent research highlights NLRPs' significant impact on various human diseases, including cancer. With differential expression across organs, NLRPs influence cancer progression by modulating immune reactions, cell fate, and proliferation. Their clinical significance in cancer makes them promising therapeutic targets. This review provides a comprehensive overview of the structure, function, activation mechanism of the NLRPs family and its potential role in cancer progression. In addition, we particularly focused on the concept of NLRP as a therapeutic target and its potential value in combination with immune checkpoint inhibitors.

Recent advances in immunotherapy for small cell lung cancer

PURPOSE OF REVIEW

This review aims to provide an overview of recent advances in immunotherapy for small cell lung cancer (SCLC), with a focus on the current status of immune checkpoint inhibitors (ICIs), novel combination strategies, and key biomarkers.

RECENT FINDINGS

The integration of ICIs into standard chemotherapy has established them as the first-line treatment for extensive-stage SCLC (ES-SCLC). The ADRIATIC trial further demonstrated the efficacy of ICI maintenance therapy in limited-stage SCLC. Additionally, combining radiotherapy with ICIs has shown promising synergistic effects, including the abscopal and radscopal effects. Ongoing investigations into the combination of ICIs with targeted therapies, such as antiangiogenic agents and DNA damage response inhibitors, have yielded encouraging preliminary results. Notably, the novel therapeutic agent tarlatamab, the first bispecific DLL3-directed CD3 T-cell engager, has recently received FDA approval for second-line treatment of ES-SCLC. Advances in omics technologies have shed light on the intra-tumor and inter-tumor heterogeneity of SCLC, leading to the identification of new molecular subtypes and biomarkers, thereby paving the way for precision medicine.

SUMMARY

Despite the improved outcomes associated with immunotherapy in SCLC, the overall clinical benefit remains modest. Further preclinical and clinical studies are essential to identify optimal treatment regimens and enhance therapeutic efficacy.

Evaluation and integration of cell-free DNA signatures for detection of lung cancer

Cell-free DNA (cfDNA) analysis has shown potential in detecting early-stage lung cancer based on non-genetic features. To distinguish patients with lung cancer from healthy individuals, peripheral blood were collected from 926 lung cancer patients and 611 healthy individuals followed by cfDNA extraction. Low-pass whole genome sequencing and targeted methylation sequencing were conducted and various features of cfDNA were evaluated. With our customized algorithm using the most optimal features, the ensemble stacked model was constructed, called ESim-seq (Early Screening tech with Integrated Model). In the independent validation cohort, the ESim-seq model achieved an area under the curve (AUC) of 0.948 (95 % CI: 0.915-0.981), with a sensitivity of 79.3 % (95 % CI: 71.5-87.0 %) across all stages at a specificity of 96.0 % (95 % CI: 90.6-100.0 %). Specifically, the sensitivity of the ESim-seq model was 76.5 % (95 % CI: 67.3-85.8 %) in stage I patients, 100 % (95 % CI: 100.0-100.0 %) in stage II patients, 100 % (95 % CI: 100.0-100.0 %) in stage III patients and 87.5 % (95 % CI: 64.6%-100.0 %) in stage IV patients in the independent validation cohort. Besides, we constructed LCSC model (Lung Cancer Subtype multiple Classification), which was able to accurately distinguish patients with small cell lung cancer from those with non-small cell lung cancer, achieving an AUC of 0.961 (95 % CI: 0.949-0.957). The present study has established a framework for assessing cfDNA features and demonstrated the benefits of integrating multiple features for early detection of lung cancer.

CAR-T cell therapy: Challenge and opportunity for effective treatment of small cell lung cancer

Small cell lung cancer (SCLC) is a devastating malignancy characterized by rapid metastasis, drug resistance, and frequent recurrence. Owing to the paucity of existing therapeutic options, the prognosis of SCLC remains poor. Recently, the combination of immune checkpoint inhibitors and chemotherapy has resulted in modest improvements in treatment responses. In this review, we characterize the biological signature of SCLC and outline the obstacles to current treatment, including impaired antigen presentation and T cell infiltration. These obstacles may potentially be overcome by chimeric antigen receptor (CAR)-T cell therapy. For the first time, we summarize the available data and discuss the future prospects of CAR-T cell therapy for the treatment of SCLC. Given the high heterogeneity and immunosuppressive tumor microenvironment of SCLC, structural modifications of CAR-T cells and combination therapy may be required to elicit a successful antitumor response. Further research, including clinical trials, is needed to determine the suitability of CAR-T cell therapy as a treatment for SCLC.

Preclinical study and phase II trial of adapting low-dose radiotherapy to immunotherapy in small cell lung cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) provide modest but unsatisfactory benefits for extensive-stage small cell lung cancer (ES-SCLC). Developing strategies for treating ES-SCLC is critical.

METHODS

We preliminarily explored the outcomes of salvage low-dose radiotherapy (LDRT) plus ICI on refractory SCLC patients. Next, we evaluated the combinational efficacy in murine SCLC. The tumor immune microenvironment (TIME) was analyzed for mechanistic study. Subsequently, we conducted a multicenter, prospective phase II trial that administered concurrent thoracic LDRT plus chemoimmunotherapy to treatment-naive ES-SCLC patients (MATCH trial, NCT04622228). The primary endpoint was confirmed objective response rate (ORR), and the key secondary endpoints included progression-free survival (PFS) and safety.

FINDINGS

Fifteen refractory SCLC patients treated with LDRT plus ICI were retrospectively reviewed. The ORR was 73.3% (95% confidence interval [CI], 44.9-92.2). We identified a specific dose of LDRT (15 Gy/5 fractions) that exhibited growth retardation and improved survival in murine SCLC when combined with ICIs. This combination recruited a special T cell population, TCF1+ PD-1+ CD8+ stem-like T cells, from tumor-draining lymph nodes into the TIME. The MATCH trial showed a confirmed ORR of 87.5% (95% CI, 75.9-94.8). The median PFS was 6.9 months (95% CI, 5.4-9.3).

CONCLUSIONS

These findings verified that LDRT plus chemoimmunotherapy was safe, feasible, and effective for ES-SCLC, warranting further investigation.

FUNDING

This research was funded by West China Hospital (no. ZYJC21003), the National Natural Science Foundation of China (no. 82073336), and the MATCH trial was fully funded by Roche (China) Holding Ltd. (RCHL) and Shanghai Roche Pharmaceuticals Ltd. (SRPL).

Impact of thoracic radiotherapy on first-line treatment outcomes in ES-SCLC patients

BACKGROUND

The therapeutic advantage of thoracic radiotherapy (tRT) as an adjunct to first-line immunotherapy and chemotherapy in patients with extensive-stage small cell lung cancer (ES-SCLC) remains unclear. We sought to elucidate this in a retrospective cohort study comparing the effectiveness and safety of tRT in combination with first-line immunotherapy and chemotherapy.

METHODS

Our retrospective study included patients with ES-SCLC, treated at the West China Hospital between January 2019 and December 2022. They received first-line immunotherapy and chemotherapy and were categorized into two cohorts based on the administration of tRT. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Cox regression analysis was utilized to identify potential independent predictors of prognosis and to compare the treatment outcomes across various patient subgroups. Treatment-related toxicities across both cohorts were compared using the Chi-squared test.

RESULTS

A total of 99patients were eligible for the study, out of which 55 received tRT. The medianduration of follow-up was 39 months. Remarkably, patients who received tRTdemonstrated superior OS and PFS in comparison to those who did not (P < 0.05). Subgroup analysis further confirmed these findings. Multivariate analysisidentified treatment group and liver metastasis as independent prognosticfactors (P < 0.05). The incidence of grade 3-4 adverse events showed nostatistically significant difference between the two cohorts.

CONCLUSIONS

Thus, weconfirmed that the addition of tRT to the conventional regimen of first-linechemotherapy and immunotherapy yields better survival outcomes without asignificant increase in toxicity.

Gut microbial metabolites in lung cancer development and immunotherapy: Novel insights into gut-lung axis

Metabolic derivatives of numerous microorganisms inhabiting the human gut can participate in regulating physiological activities and immune status of the lungs through the gut-lung axis. The current well-established microbial metabolites include short-chain fatty acids (SCFAs), tryptophan and its derivatives, polyamines (PAs), secondary bile acids (SBAs), etc. As the study continues to deepen, the critical function of microbial metabolites in the occurrence and treatment of lung cancer has gradually been revealed. Microbial derivates can enter the circulation system to modulate the immune microenvironment of lung cancer. Mechanistically, oncometabolites damage host DNA and promote the occurrence of lung cancer, while tumor-suppresive metabolites directly affect the immune system to combat the malignant properties of cancer cells and even show considerable application potential in improving the efficacy of lung cancer immunotherapy. Considering the crosstalk along the gut-lung axis, in-depth exploration of microbial metabolites in patients' feces or serum will provide novel guidance for lung cancer diagnosis and treatment selection strategies. In addition, targeted therapeutics on microbial metabolites are expected to overcome the bottleneck of lung cancer immunotherapy and alleviate adverse reactions, including fecal microbiota transplantation, microecological preparations, metabolite synthesis and drugs targeting metabolic pathways. In summary, this review provides novel insights and explanations on the intricate interplay between gut microbial metabolites and lung cancer development, and immunotherapy through the lens of the gut-lung axis, which further confirms the possible translational potential of the microbiome metabolome in lung cancer treatment.

Neoadjuvant low-dose radiotherapy plus durvalumab and chemotherapy for potentially resectable stage III NSCLC: A phase Ib dose-escalation study

BACKGROUND AND PURPOSE

This phase Ib study was designed to assess the safety/tolerability and preliminary antitumor activity of neoadjuvant low-dose radiotherapy (LDRT) plus durvalumab and chemotherapy for potentially resectable stage III non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Eligible patients received dose-escalated radiotherapy (10 Gy in 5 fractions [cohort 1], 20 Gy in 10 fractions [cohort 2], and 30 Gy in 15 fractions [cohort 3]) according to a 3 + 3 design, with concurrent durvalumab plus standard chemotherapy for two cycles. Primary objective was safety/tolerability. Secondary objectives included major pathological response (MPR), pathological complete response (pCR), event-free survival (EFS), and exploratory biomarker analysis.

RESULTS

Nine patients were enrolled and completed the planned neoadjuvant therapy. No dose-limiting toxicity was recorded. Grade 3-4 treatment-related adverse events were observed in three (33.3 %) patients. Seven (77.8 %) patients successfully converted to resectable cases with R0 resection. No treatment-related surgical delay or death was reported. The MPR and pCR rates were both 33.3 % % (1/3) for cohort 1, 66.7 % (2/3) and 0.0 % for cohort 2, and 100.0 % (3/3), and 66.7 % (2/3) for cohort 3. At data cutoff, the 12 month-EFS rates were 33.3 %, 66.7 %, and 100 % for three cohorts, respectively. By biomarker analysis, TMB values were higher in either pathologically or radiologically responders than in others (all p > 0.05).

CONCLUSION

Neoadjuvant LDRT plus durvalumab and chemotherapy was well-tolerated in potentially resectable stage III NSCLC. The preliminary efficacy supports this combined regimen's potential, the optimal radiotherapy dosage was determined to be 30 Gy in 15 fractions, warranting further clinical investigation.

Oncogenic functions and therapeutic potentials of targeted inhibition of SMARCAL1 in small cell lung cancer

Small cell lung cancer (SCLC) is a recalcitrant cancer characterized by high frequency loss-of-function mutations in tumor suppressors with a lack of targeted therapy due to absence of high frequency gain-of-function abnormalities in oncogenes. SMARCAL1 is a member of the ATP-dependent chromatin remodeling protein SNF2 family that plays critical roles in DNA damage repair and genome stability maintenance. Here, we showed that SMARCAL1 was overexpressed in SCLC patient samples and was inversely associated with overall survival of the patients. SMARCAL1 was required for SCLC cell proliferation and genome integrity. Mass spectrometry revealed that PAR6B was a downstream SMARCAL1 signal molecule which rescued inhibitory effects caused by silencing of SMARCAL1. By screening of 36 FDA-approved clinically available agents related to DNA damage repair, we found that an aza-anthracenedione, pixantrone, was a potent SMARCAL1 inhibitor which suppressed the expression of SMARCAL1 and PAR6B at protein level. Pixantrone caused DNA damage and exhibited inhibitory effects on SCLC cells in vitro and in a patient-derived xenograft mouse model. These results indicated that SMARCAL1 functions as an oncogene in SCLC, and pixantrone as a SMARCAL1 inhibitor bears therapeutic potentials in this deadly disease.

Treatment patterns and clinical outcomes in 157 patients with extensive-stage small cell lung cancer: real-world evidence from a single-center retrospective study

Background

Immune checkpoint inhibitors (ICIs) have changed the therapeutic options for extensive-stage small-cell lung cancer (ES-SCLC). In this real-world study, we analyzed the treatment patterns in patients with ES-SCLC and evaluated the efficacy of chemotherapy combined with immunotherapy as first-line therapy.

Methods

A retrospective analysis was performed on patients with ES-SCLC who received treatment at China-Japan Friendship Hospital (Beijing, China) between August 1, 2020, and April 30, 2023. The treatment patterns appeared in the form of Sunburst Chart and Sankey diagram. The survival analyses were conducted by Kaplan-Meier curves.

Results

A total of 157 patients with ES-SCLC were retrospectively included. According to first-line therapy, patients were divided into the chemotherapy (CT) group (n=82) and chemo-immunotherapy (CIT) group (n=75). The median treatment lines were 2[1, 2] and cycles were 8[5, 12], respectively. 82 patients received the second line of therapy, followed by 37 for the third, 15 for the fourth, 11 for the fifth, and 5 for the sixth. Overall, the treatment patterns involved 11 options including 12 chemotherapy regimens, 11 ICIs, and 4 targeted agents. The second-line treatment pattern had the most options (9) and regimens (43). In the first 3 lines, chemotherapy was the largest proportion of treatment options. The addition of ICIs prolonged progression-free survival from 6.77 (95% confidence interval [CI], 6.00-7.87) to 7.33 (95% CI, 6.03-9.80) months (hazard ratio [HR]=0.67, 95% CI, 0.47-0.95; P=0.025), overall survival from 12.97 (10.90-23.3) to 14.33 (12.67-NA) months without statistically significant difference (HR=0.86, 95% CI, 0.55-1.34; P=0.505).

Conclusion

The treatment options of patients with ES-SCLC are more diversified. Combination therapy is the current trend, where chemotherapy is the cornerstone. Meanwhile, ICIs participate in almost all lines of treatment. However, the clinical efficacy remains barely satisfactory. We are urgently expecting more breakthrough therapies except immunology will be applied in the clinic.

Exploration of potential novel drug targets and biomarkers for small cell lung cancer by plasma proteome screening

Background: Small cell lung cancer (SCLC) is characterized by extreme invasiveness and lethality. There have been very few developments in its diagnosis and treatment over the past decades. It is urgently needed to explore potential novel biomarkers and drug targets for SCLC. Methods: Two-sample Mendelian Randomization (MR) was performed to investigate causal associations between SCLC and plasma proteins using genome-wide association studies (GWAS) summary statistics of SCLC from Transdisciplinary Research Into Cancer of the Lung Consortium (nCase = 2,791 vs. nControl = 20,580), and was validated in another cohort (nCase = 2,664 vs. nControl = 21,444). 734 plasma proteins and their genetic instruments of cis-acting protein quantitative trait loci (pQTL) were used, whereas external plasma proteome data was retrieved from deCODE database. Bidirectional MR, Steiger filtering and phenotype scanning were applied to further verify the associations. Results: Seven significant (p < 6.81 × 10-5) plasma protein-SCLC pairs were identified by MR analysis, including ACP5 (OR = 0.76, 95% CI: 0.67-0.86), CPB2 (OR = 0.90, 95% CI: 0.86-0.95), GSTM3 (OR = 0.45, 95% CI: 0.33-0.63), SHMT1 (OR = 0.74, 95% CI: 0.64-0.86), CTSB (OR = 0.79, 95% CI: 0.71-0.88), NTNG1 (OR = 0.81, 95% CI: 0.74-0.90) and FAM171B (OR = 1.40, 95% CI: 1.21-1.62). The external validation confirmed that CPB2, GSTM3 and NTNG1 had protective effects against SCLC, while FAM171B increased SCLC risk. However, the reverse causality analysis revealed that SCLC caused significant changes in plasma levels of most of these proteins, including decreases of ACP5, CPB2, GSTM3 and NTNG1, and the increase of FAM171B. Conclusion: This integrative analysis firstly suggested the causal associations between SCLC and plasma proteins, and the identified several proteins may be promising novel drug targets or biomarkers for SCLC.

Longitudinal detection of subcategorized CD44v6+ CTCs and circulating tumor endothelial cells (CTECs) enables novel clinical stratification and improves prognostic prediction of small cell lung cancer: A prospective, multi-center study

Current management of small cell lung cancer (SCLC) remains challenging. Effective biomarkers are needed to subdivide patients presenting distinct treatment response and clinical outcomes. An understanding of heterogeneous phenotypes of aneuploid CD31- circulating tumor cells (CTCs) and CD31+ circulating tumor endothelial cells (CTECs) may provide novel insights in the clinical management of SCLC. In the present translational and prospective study, increased cancer metastasis-related cell proliferation and motility, accompanied with up-regulated mesenchymal marker vimentin but down-regulated epithelial marker E-cadherin, were observed in both lentivirus infected SCLC and NSCLC cells overexpressing the stemness marker CD44v6. Aneuploid CTCs and CTECs expressing CD44v6 were longitudinally detected by SE-iFISH in 120 SCLC patients. Positive detection of baseline CD44v6+ CTCs and CD44v6+ CTECs was significantly associated with enhanced hepatic metastasis. Karyotype analysis revealed that chromosome 8 (Chr8) in CD44v6+ CTCs shifted from trisomy 8 towards multiploidy in post-therapeutic patients compared to pre-treatment subjects. Furthermore, the burden of baseline CD44v6+ CTCs (t0) or amid the therapy (t1-2), the ratio of baseline CD31+ CTEC/CD31- CTC (t0), and CTC-WBC clusters (t0) were correlated with treatment response and distant metastases, particularly brain metastasis, in subjects with limited disease (LD-SCLC) but not in those with extensive disease (ED-SCLC). Multivariate survival analysis validated that longitudinally detected CD44v6+/CD31- CTCs was an independent prognostic factor for inferior survival in SCLC patients. Our study provides evidence for the first time that comprehensive analyses of CTCs, CTECs, and their respective CD44v6+ subtypes enable clinical stratification and improve prognostic prediction of SCLC, particularly for potentially curable LD-SCLC.