Multiple Primary Lung Cancers: A New Challenge in the Era of Precision Medicine

The dynamic duo: A narrative review on the synergy between stereotactic body radiotherapy and immunotherapy in lung cancer treatment (Review)

Immunotherapy, particularly immune checkpoint inhibitors (ICIs), is undoubtedly one of the major breakthroughs in lung cancer research. Patient survival and prognosis have all been improved as a result, although numerous patients do not respond to immunotherapy due to various immune escape mechanisms of the tumor cells. Recent preclinical and clinical evidence has shown that stereotactic body radiotherapy (SBRT), also known as stereotactic ablative radiotherapy, has a prominent immune priming effect that could elicit antitumor immunity against specific tumor antigens and destroy distant tumor cells, thereby achieving the elusive abscopal effect, with the resulting immuno‑active tumor environment also being more conducive to ICIs. Some landmark trials have already demonstrated the survival benefit of the dynamic duo of SBRT plus immunotherapy in metastatic non‑small‑cell lung cancer, while others such as PEMBRO‑RT further suggest that the addition of SBRT to immunotherapy could expand the current indication to those who have historically responded poorly to ICIs. In the present review, the biological mechanisms that drive the synergistic effect of SBRT and immunotherapy were first briefly outlined; then, the current understanding from clinical trials was summarized and new insight into the evolving role of immunotherapy and SBRT synergy in lung cancer treatment was provided. Finally, novel avenues for discovery were highlighted. The innovation of the present review lies in the inclusion of non‑ICI immunotherapy in the discussion, which provides a more comprehensive view on the current development and future trend of SBRT + immunotherapy synergy.

The activity and immune dynamics of PD-1 inhibition on high-risk pulmonary ground glass opacity lesions: insights from a single-arm, phase II trial

Immune checkpoint inhibitors targeting the programmed cell death-1 (PD-1) protein significantly improve survival in patients with advanced non-small-cell lung cancer (NSCLC), but its impact on early-stage ground-glass opacity (GGO) lesions remains unclear. This is a single-arm, phase II trial (NCT04026841) using Simon's optimal two-stage design, of which 4 doses of sintilimab (200 mg per 3 weeks) were administrated in 36 enrolled multiple primary lung cancer (MPLC) patients with persistent high-risk (Lung-RADS category 4 or had progressed within 6 months) GGOs. The primary endpoint was objective response rate (ORR). T/B/NK-cell subpopulations, TCR-seq, cytokines, exosomal RNA, and multiplexed immunohistochemistry (mIHC) were monitored and compared between responders and non-responders. Finally, two intent-to-treat (ITT) lesions (pure-GGO or GGO-predominant) showed responses (ORR: 5.6%, 2/36), and no patients had progressive disease (PD). No grade 3-5 TRAEs occurred. The total response rate considering two ITT lesions and three non-intent-to-treat (NITT) lesions (pure-solid or solid-predominant) was 13.9% (5/36). The proportion of CD8+ T cells, the ratio of CD8+/CD4+, and the TCR clonality value were significantly higher in the peripheral blood of responders before treatment and decreased over time. Correspondingly, the mIHC analysis showed more CD8+ T cells infiltrated in responders. Besides, responders' cytokine concentrations of EGF and CTLA-4 increased during treatment. The exosomal expression of fatty acid metabolism and oxidative phosphorylation gene signatures were down-regulated among responders. Collectively, PD-1 inhibitor showed certain activity on high-risk pulmonary GGO lesions without safety concerns. Such effects were associated with specific T-cell re-distribution, EGF/CTLA-4 cytokine compensation, and regulation of metabolism pathways.

Metachronous and Synchronous Triple Primary Lung Cancers in a Chronic Smoker

Multiple primary lung cancers (MPLCs), characterized by the presence of more than one distinct primary lung tumors, may develop either synchronously (simultaneously) or metachronously (after initial cancer treatment). This case describes a rare occurrence of three primary lung cancers in a chronic smoker. After a lobectomy for right middle lobe adenocarcinoma (ADC), the patient was diagnosed with synchronous small cell carcinoma (SCLC) in the right upper lobe and squamous cell carcinoma (SCC) in the right lower lobe. Notably, the ADC and subsequent lung cancers were metachronous. Due to her unsuitability for surgery, the patient pursued a treatment regimen involving radiation therapy, chemotherapy, and immunotherapy. This case underscores the need for vigilant identification and comprehensive management of MPLCs, particularly in high-risk patients, to improve outcomes and reduce the burden of this rare condition.

Resectable non-stage IV nonsmall cell lung cancer: the surgical perspective

Surgery remains an essential element of the multimodality radical treatment of patients with early-stage nonsmall cell lung cancer. In addition, thoracic surgery is one of the key specialties involved in the lung cancer tumour board. The importance of the surgeon in the setting of a multidisciplinary panel is ever-increasing in light of the crucial concept of resectability, which is at the base of patient selection for neoadjuvant/adjuvant treatments within trials and in real-world practice. This review covers some of the topics which are relevant in the daily practice of a thoracic oncological surgeon and should also be known by the nonsurgical members of the tumour board. It covers the following topics: the pre-operative selection of the surgical candidate in terms of fitness in light of the ever-improving nonsurgical treatment alternatives unfit patients may benefit from; the definition of resectability, which is so important to include patients into trials and to select the most appropriate radical treatment; the impact of surgical access and surgical extension with the evolving role of minimally invasive surgery, sublobar resections and parenchymal-sparing sleeve resections to avoid pneumonectomy.

Susceptibility Genes Associated with Multiple Primary Cancers

With advancements in treatment and screening techniques, we have been witnessing an era where more cancer survivors harbor multiple primary cancers (MPCs), affecting approximately one in six patients. Identifying MPCs is crucial for tumor staging and subsequent treatment choices. However, the current clinicopathological criteria for clinical application are limited and insufficient, making it challenging to differentiate them from recurrences or metastases. The emergence of next-generation sequencing (NGS) technology has provided a genetic perspective for defining multiple primary cancers. Researchers have found that, when considering multiple tumor pairs, it is crucial not only to examine well-known essential mutations like MLH1/MSH2, EGFR, PTEN, BRCA1/2, CHEK2, and TP53 mutations but also to explore certain pleiotropic loci. Moreover, specific deleterious mutations may serve as regulatory factors in second cancer development following treatment. This review aims to discuss these susceptibility genes and provide an explanation of their functions based on the signaling pathway background. Additionally, the association network between genetic signatures and different tumor pairs will be summarized.

Bilateral synchronous multiple lung cancer: an emerging problem

Aim

Multiple primary lung cancers are becoming increasingly recognised and pose diagnostic and staging uncertainties with challenging management options and prognostication.

Case report

We describe a case of synchronous multiple primary lung cancer occurring bilaterally, and the steps in reaching the diagnosis, initial surgical management, the intensive follow-up this underwent, and how its subsequent recurrence led to treatment with radiation therapy in light of the patient's declining fitness.

Discussion

This case highlighted that cytological recurrence could occur prior to radiological recurrence, especially for endobronchial tumors, and intensive follow-up both radiologically and endoscopically with multidisciplinary input is crucial in the management of these challenging cases where evidence-based guidelines are limited.

Lobar or sublobar resection for early-stage second primary lung cancer ≤ 3 cm in size: a SEER population-based study

PURPOSE

Surgical strategy for second primary lung cancer (SPLC) may be more conservative due to influence of first primary lung cancer (FPLC). The optimal surgical method for SPLC warrants discussion. We aimed to explore a more suitable surgical approach for early-stage (T1-T2N0, ≤ 3 cm) SPLC and provide insights for clinical practice.

METHODS

A retrospective study was conducted using data from the Surveillance, Epidemiology and End Results database between 2004 and 2018, and data of patients with early-stage SPLC who underwent secondary surgery were collected. Propensity score matching (PSM) reduced potential bias between lobar and sublobar resection groups. The effect of lobar and sublobar resection on overall survival (OS) was assessed in all patients and subgroups.

RESULTS

A total of 714 patients who met the study entry criteria were enrolled, including 476 patients in the sublobar resection group (66.67%) and 238 patients in the lobar resection group (33.33%). There was no difference in OS between the lobar and sublobar resection groups before and after PSM (P = 0.289) and (P = 0.608), respectively. Subgroup analyses showed that lobar resection achieved a significantly better OS than sublobar resection only in patients with an SPLC tumor size of 2-3 cm (P < 0.05).

CONCLUSION

The OS of sublobar resection was not significantly different from that of lobar resection for early-stage SPLC. For SPLC with a 2-3 cm tumor size, lobar resection is more advantageous than sublobar resection.

Immunohistochemistry combined with NGS to assist the differential diagnosis of multiple primary lung cancer with lymph node metastasis: a case report

In recent years, the incidence of synchronous multiple primary lung cancers (MPLCs) has gradually increased. Surgery is the preferred treatment for these patients. There are great differences in the driving genes between individual tumors in patients with MPLC, and tumors with targeted mutations do not represent other tumors, which challenges the selection of targeted therapies for patients with MPLC. Driving mutations in each lesion after surgery are crucial for establishing accurate pathological staging and subsequent treatment strategies. There are some mutated genes in the lymph nodes of postoperative metastatic MPLCs, and the tumor cell count/DNA concentration is low, which limits the next-generation sequencing (NGS) detection effect. A combination with immunohistochemistry to determine the source of metastasis may be a better choice. This study reports a rare case of lung cancer with double primary adenocarcinomas of the lung combined with 10 groups of lymph node metastases. The source of metastasis was identified using immunohistochemistry combined with NGS to guide postoperative adjuvant treatment. We hope that this case report can provide new ideas for the identification of MPLCs and assist in their diagnosis and individualized treatment. In addition, the combination specific immunohistochemistry and NGS seems to be an effective identification method. This approach can provide clinical benefits; however, this still requires further exploration through studies with large sample sizes.

Multidirectional characterization of cellular composition and spatial architecture in human multiple primary lung cancers

Multiple primary lung cancers (MPLCs) pose diagnostic and therapeutic challenges in clinic. Here, we orchestrated the cellular and spatial architecture of MPLCs by combining single-cell RNA-sequencing and spatial transcriptomics. Notably, we identified a previously undescribed sub-population of epithelial cells termed as CLDN2⁺ alveolar type II (AT2) which was specifically enriched in MPLCs. This subtype was observed to possess a relatively stationary state, play a critical role in cellular communication, aggregate spatially in tumor tissues, and dominate the malignant histopathological patterns. The CLDN2 protein expression can help distinguish MPLCs from intrapulmonary metastasis and solitary lung cancer. Moreover, a cell surface receptor-TNFRSF18/GITR was highly expressed in T cells of MPLCs, suggesting TNFRSF18 as one potential immunotherapeutic target in MPLCs. Meanwhile, high inter-lesion heterogeneity was observed in MPLCs. These findings will provide insights into diagnostic biomarkers and therapeutic targets and advance our understanding of the cellular and spatial architecture of MPLCs.

Comparison of outcome after stereotactic ablative radiotherapy of patients with metachronous lung versus primary lung cancer

BACKGROUND

Early-stage lung cancer, primarily treated with surgery, often occur in poor surgical candidates (impaired respiratory function, prior thoracic surgery, severe comorbidities). Stereotactic ablative radiotherapy (SABR) is a non-invasive alternative that provides comparable local control. This technique is particularly relevant for surgically resectable metachronous lung cancer, in patients unable to undergo surgery.. The objective of this study is to evaluate the clinical outcome of patients treated with SABR for stage I metachronous lung cancer (MLC) versus stage I primary lung cancer (PLC).

PATIENTS AND METHODS

137 patients treated with SABR for stage I non-small cell lung cancer were retrospectively reviewed, of which 28 (20.4%) were MLC and 109 (79.6%) were PLC. Cohorts were evaluated for differences in overall survival (OS), progression-free survival (PFS), metastasis-free survival, local control (LC), and toxicity.

RESULTS

After SABR, patients treated for MLC have comparable median age (76.6 vs 78.6, p = 0.2), 3-year LC (83.6% vs. 72.6%, p = 0.2), PFS (68.7% vs. 50.9%, p = 0.9), and OS (78.6% vs. 52.1%, p = 0.9) as PLC, along with similar rates of total (54.1% vs. 42.9%, p = 0.6) and grade 3 + toxicity (3.7% vs. 3.6%, p = 0.9). Previous treatment of MLC patients was either surgery (21/28, 75%) or SABR (7/28, 25%). The median follow-up was 53 months.

CONCLUSION

SABR is a safe and effective approach for localized metachronous lung cancer.

Genetic trajectory and clonal evolution of multiple primary lung cancer with lymph node metastasis

Multiple primary lung cancer (MPLC) with lymph node metastasis (LNM) is a rare phenomenon of multifocal lung cancer. The genomic landscapes of MPLC and the clonal evolution pattern between primary lung lesions and lymph node metastasis haven't been fully illustrated. We performed whole-exome sequencing (WES) on 52 FFPE (Formalin-fixed Paraffin-Embedded) samples from 11 patients diagnosed with MPLC with LNM. Genomic profiling and phylogenetic analysis were conducted to infer the evolutional trajectory within each patient. The top 5 most frequently mutated genes in our study were TTN (76.74%), MUC16 (62.79%), MUC19 (55.81%), FRG1 (46.51%), and NBPF20 (46.51%). For most patients in our study, a substantial of genetic alterations were mutually exclusive among the multiple pulmonary tumors of the same patient, suggesting their heterogenous origins. Individually, the genetic profile of lymph node metastatic lesions overlapped with that of multiple lung cancers in different degrees but are more genetically related to specific pulmonary lesions. SETD2 was a potential metastasis biomarker of MPLC. The mean putative neo-antigen number of the primary tumor (646.5) is higher than that of lymph node metastases (300, p = 0.2416). Primary lung tumors and lymph node metastases are highly heterogenous in immune repertoires. Our findings portrayed the comprehensive genomic landscape of MPLC with LNM. We characterized the genomic heterogeneity among different tumors. We offered novel clues to the clonal evolution between MPLC and their lymphatic metastases, thus advancing the treatment strategies and preventions of MPLC with LNM.

A Novel Prognostic Score Based on Multiple Quantitative Parameters of Chest CT for Patients with Synchronous Multiple Primary Lung Cancer: Is Solid Component Size a Better Prognostic Indicator?

BACKGROUND

There is no simple and definitive way to predict the prognosis of synchronous multiple primary lung cancer (SMPLC). In this study, we developed a clinical prognostic score for predicting the survival of patients with SMPLC.

PATIENTS AND METHODS

This study included 206 patients with SMPLC between 2011 and 2020 at three hospitals. Kaplan-Meier analysis was used to determine the optimal cutoff values for the quantitative chest computed tomography (CT) parameters. Multivariable Cox proportional hazards regression was carried out to identify independent prognostic factors for predicting overall survival (OS) and disease-free survival (DFS). The time-dependent receiver operating characteristic curve was analyzed to evaluate the prognostic performance.

RESULTS

A CT-based prognostic score (CTPS) comprising six chest CT parameters was developed. Compared with T stage, CTPS had a higher prediction accuracy for OS and DFS. All C-indices of the model reached a satisfactory level in both the development and validation cohorts. Significant differences in the OS and DFS curves were observed when the patients were stratified into different risk groups. The high-risk group (CTPS of 5-6) had poorer survival than the low-risk group (CTPS of 0-4).

CONCLUSIONS

The developed CTPS and the corresponding risk stratification system are valid for predicting the survival of patients with SMPLC.

Identification of nine mutant genes and establishment of three prediction models of organ tropism metastases of non-small cell lung cancer

BACKGROUND

Most Non-small cell lung cancer (NSCLC) patients tend to have metastases at the initial diagnosis. However, limited knowledge has been established regarding which factors, are associated with its metastases. This study aims to identify more biomarkers associated with its organ tropism metastasis and to establish models for prediction of its metastatic organs.

METHODS

We performed targeted next-generation sequencing (NGS) to detect genes related to lung cancer in 272 patients with primary advanced NSCLC from Northeast China. We adopted Fisher test, multivariate logistic regression analysis to identify metastasis-related gene mutations and to establish prediction models.

RESULTS

Mutations of EGFR (p = 0.0003, OR = 2.554) (especially EGFR L858R [p = 0.02, OR = 2.009]), ATM (p = 0.008, OR = 11.032), and JAK2 (p = 0.009, OR = Inf) were positively and of TP53 exon4mut (p = 0.001, OR = 0.173) was negatively correlated with lung metastasis, and those of CSF1R (p = 0.01, OR = Inf), KIT (p = 0.03, OR = 4.746), MYC (p = 0.05, OR = 7.938), and ERBB2 (p = 0.02, OR = 2.666) were positively correlated with pleural dissemination; those of TP53 (p = 0.01, OR = 0.417) was negatively, while of SMAD4 (p = 0.03, OR = 4.957) was positively correlated with brain metastasis of NSCLC. Additionally, smoking history (p = 0.004, OR = 0.004) was negatively correlated with pleural dissemination of NSCLC. Furthermore, models for prediction of lung metastasis (AUC = 0.706), pleural dissemination (AUC = 0.651), and brane metastasis (AUC = 0.629) were established.

CONCLUSION

Taken together, this study revealed nine mutant genes and smoking history associated with organ tropism metastases of NSCLC and provided three models for the prediction of metastatic organs. This study enables us to predict the organs to which non-small cell lung cancer metastasizes before it does develop.

Long Noncoding RNA LAMTOR5-AS1 Interference Affects MicroRNA-506-3p/E2F6-Mediated Behavior of Non-Small Cell Lung Cancer Cells

Long noncoding RNA LAMTOR5 antisense RNA 1 (LAMTOR5-AS1) has been certified as a risk predictor and diagnostic biomarker of prostate cancer. However, the expression and exact roles of LAMTOR5-AS1 in non-small cell lung cancer (NSCLC) remain unclear. Thus, we measured LAMTOR5-AS1 expression in NSCLC and gauged its clinical value. The detailed roles and downstream working mechanism of LAMTOR5-AS1 in NSCLC were comprehensively unraveled. qRT-PCR was applied to measure gene expression. Functionally, utilizing small interfering RNA, LAMTOR5-AS1 was ablated, and the functional alterations were addressed by means of different experiments. The targeting activities between LAMTOR5-AS1 and microRNA-506-3p (miR-506-3p) and between miR-506-3p and E2F transcription factor 6 (E2F6) were confirmed by RNA immunoprecipitation and luciferase reporter assays. LAMTOR5-AS1 overexpression in NSCLC was verified in TCGA datasets and our own cohort and manifested an evident relationship with poor prognosis. Interference with LAMTOR5-AS1 led to repression of the proliferation, cloning, and metastasis abilities of NSCLC cells in vitro. We further confirmed an obvious increase in LAMTOR5-AS1-silenced NSCLC cell apoptosis. Furthermore, the absence of LAMTOR5-AS1 restricted tumor growth in vivo. Mechanistically, LAMTOR5-AS1 sponged miR-506-3p in NSCLC cells. Furthermore, E2F6, a downstream target of miR-506-3p, was under the control of LAMTOR5-AS1, which was realized by decoying miR-506-3p. Rescue experiments showed that miR-506-3p suppression or E2F6 reintroduction was capable of remitting LAMTOR5-AS1 deficiency-triggered anticarcinogenic actions in NSCLC. Our study confirmed the exact roles of LAMTOR5-AS1 for the first time and revealed that LAMTOR5-AS1 knockdown disrupts the malignancy of NSCLC by targeting the miR-506-3p/E2F6 axis. Targeting the LAMTOR5-AS1/miR-506-3p/E2F6 pathway may be instrumental for managing patients with NSCLC.

MicroRNA-449a delays lung cancer development through inhibiting KDM3A/HIF-1α axis

Background

It has been established that microRNA (miR)-449a is anti-tumorigenic in cancers, including lung cancer. Therefore, this study further explored miR-449a-mediated mechanism in lung cancer, mainly focusing on lysine demethylase 3A/hypoxia-induced factor-1α (KDM3A/HIF-1α) axis.

Methods

miR-449a, KDM3A and HIF-1α levels in lung cancer tissues and cell lines (A549, H1299 and H460) were measured. Loss- and gain-of-function assays were performed and then cell proliferation, cell cycle, apoptosis, invasion and migration were traced. The relationship between KDM3A, miR-449a and HIF-1α was verified. Tumor growth in vivo was also monitored.

Results

Both lung cancer tissues and cells exhibited reduced miR-449a and raised KDM3A and HIF-1α levels. miR-449a interacted with KDM3A; HIF-1α could bind with KDM3A. Up-regulating miR-449a hindered while suppressing miR-449a induced lung cancer development via mediating HIF-1α. Elevating KDM3A promoted cellular aggression while down-regulating KDM3A had the opposite effects. Up-regulating KDM3A or HIF-1α negated up-regulated miR-449a-induced effects on cellular growth in lung cancer. Restoring miR-449a impaired tumorigenesis in vivo in lung cancer.

Conclusion

It is eventually concluded that miR-449a delays lung cancer development through suppressing KDM3A/HIF-1α axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02881-8.