Concurrent EGFR-TKI and Thoracic Radiotherapy as First-Line Treatment for Stage IV Non-Small Cell Lung Cancer Harboring EGFR Active Mutations

Appropriate delay of primary tumour radiotherapy may lead to better long-term overall survival for non-small cell lung cancer treated with EGFR-TKIs

PURPOSE

The most appropriate time of primary tumor radiotherapy in non-small cell lung cancer(NSCLC) with EGFR-TKIs remains unclear. The aim of this study was to investigate the effect of the time factor of primary tumor radiotherapy on long-term overall survival(OS)and provide a theoretical basis for further clinical research.

PATIENTS AND METHODS

In total, 238 patients with EGFR-TKIs and OS ≥ 12 months were statistically analysed. Patients were grouped: the D group without primary tumor radiotherapy and the R group with it.The R group were divided into three groups according to the interval between the start of EGFR-TKIs and the start of primary tumor radiotherapy: R0 - 30(<30 days), R30 - PD(≥ 30 days and disease stable), and RPD(radiotherapy after disease progression). The Kaplan-Meier method and log-rank test were used for survival analyses. Exploratory landmark analyses were investigated.

RESULTS

The OS rates at 1, 2, 3, 5 years for the R group and D group were 96.8%, 62.9%, 38.3%, 17.1%, and 95.6%, 37.7%, 21.8%, 2.9%, respectively; the corresponding MST was 29 months(95% CI: 24.3-33.7) for the R group and 22 months(95% CI: 20.4-23.6) for the D group (χ2 = 13.480, p<0.001). Multivariate analysis revealed that primary tumor radiotherapy was independent predictors of prolonged OS.Among the four groups, The R30 - PD appeared to have the best OS (D, χ2 = 19.307, p<0.001;R0 - 30, χ2 = 11.687, p = 0.01; RPD, χ2 = 4.086, p = 0.043). Landmark analyses(22 months) showed the R30 - PD group had a significant long-term OS.The incidence of radiation pneumonitis ≥ grade 2 was17.3%(n = 19)and radiation esophagitis ≥ grade 2 was observed in 32 patients(29.1%).

CONCLUSIONS

Our results showed that primary tumour radiotherapy may prolong long-term OS with acceptable toxicities. Appropriate delay(R30 - PD)of primary tumour radiotherapy may be the best choice.Premature radiotherapy(R0 - 30) and radiotherapy after disease progression (RPD)may not be reasonable for long-term OS.

Thoracic radiation in combination with erlotinib-results from a phase 2 randomized trial

Background

Radiotherapy (RT) can be used to reduce symptoms and maintain open airways for patients with non-small cell lung cancer when systemic treatment is not sufficient. For some patients, tumor control is not achieved due to radioresistance. Concurrent inhibition of epidermal growth factor receptors has been proposed as a strategy to overcome radioresistance but may increase toxicity. We performed a randomized trial to assess the efficacy, tolerance, and quality of life of concurrent erlotinib and palliative thoracic RT for patients with advanced non-small cell lung cancer.

Methods

Patients were randomized 1:1 to RT alone (arm A) or in combination with erlotinib (arm B). A computed tomography (CT) scan at baseline and one at 4-12 weeks after inclusion was used to evaluate treatment response. Adverse events were registered during treatment and the subsequent 30 days. Health-related quality-of-life questionnaires were completed by the patients at baseline, weeks 2, 6, and 20.

Results

A total of 114 patients were included. Of the 74 patients with CT scans available for evaluation of treatment effect, there were no significant differences in tumor size reduction between the two groups: median 14.5% reduction in the control arm A and 17.0% in the erlotinib arm B (p = 0.68). Overall survival was not significantly different between the two treatment arms: 7.0 and 7.8 months in arm A and arm B, respectively (log-rank p = 0.32). There was no significant increase in adverse events in the experimental arm, other than what is expected from erlotinib treatment alone. Overall, patients reported similar quality of life in both treatment arms.

Conclusion

Concurrent erlotinib and palliative thoracic RT for patients with advanced non-small cell lung cancer was well tolerated but did not improve the efficacy of the RT.

Clinical trial registration

ClinicalTrials.gov, identifier NCT02714530.

T790M mutation sensitizes non-small cell lung cancer cells to radiation via suppressing SPOCK1

Background

Approximately 50% of patients harbor the T790M mutation after developing first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance. Evidence has showed the major treatment failure is local relapses and limited metastases. Several studies have demonstrated the value of radiotherapy in metastatic non-small cell lung cancer (NSCLC) with the EGFR T790M mutation after the development of TKI resistance. The aim of this study was to explore the role of radiation in T790M-mutant NSCLC and the value of early radiotherapy for NSCLC with T790M-mediated EGFR-TKI resistance.

Methods

Gefitinib-resistant NSCLC cell lines were established via stepwise exposure to increasing concentrations of gefitinib (PC-9-GR). Droplet digital PCR was used to determine the relative T790M subclone abundance. In vitro and in vivo models were established using different mixtures of PC-9-GR and PC-9 cells. Differentially expressed genes were identified using RNA sequencing. Two research models were constructed (salvage and prophylactic radiotherapy) to determine the effects of early radiotherapy on gefitinib-resistant cells.

Results

PC-9-GR cells exhibited higher radiosensitivity than PC-9 cells (sensitivity enhancement ratio = 1.5). Salvage radiation reduced the number of T790M-mutant subclones, and the relative T790M abundance was significantly lower than that without radiation at 90 days (10.94% vs. 21.54%). Prophylactic radiation prevented the development of T790M subclones. These results were also confirmed in vivo. qRT-PCR revealed threefold elevation of miR-1243 in PC-9-GR cells, and the increased radiosensitivity of PC-9-GR cells was inhibited when miR-1243 was knocked down. RNA sequencing revealed that SPOCK1 was downregulated in PC-9-GR cells. Interestingly, bioinformatic analysis showed that SPOCK1 was a target gene of miR-1243. SPOCK1 knockdown markedly increased the radiosensitivity of PC-9 cells.

Conclusion

Gefitinib-resistant NSCLC with the T790M mutation had higher radiosensitivity than that without the mutation, possibly mediated by SPOCK1. Early radiotherapy can eliminate T790M subclones, providing evidence for the benefit of early local treatment in patients with TKI-resistant NSCLC.

Narrative review of stereotactic body radiation therapy combined with tyrosine kinase inhibitors for oligometastatic EGFR-mutated non-small cell lung cancer: present and future developments

Background and Objective

A significant number of individuals diagnosed with non-small cell lung cancer (NSCLC) have distant metastases, and the concept of oligometastatic NSCLC has shown promise in achieving a cure. Stereotactic body radiation therapy (SBRT) is currently considered a viable treatment option for a limited number of tumor metastases. It has also been demonstrated that third-generation tyrosine kinase inhibitors (TKIs) are effective in extending the survival of patients with epidermal growth factor receptor (EGFR)-mutated NSCLC. Hence, the combination of SBRT with third-generation TKIs holds the potential to enhance treatment efficacy in patients with oligometastatic EGFR-mutated NSCLC. This review aimed to assess the possibility of combining SBRT with TKIs as an optimum treatment option for patients with oligometastatic EGFR-mutated NSCLC.

Methods

We performed a narrative review by searching the PubMed, Web of Science, Elsevier and ClinicalTrials.gov databases for articles published in the English language from January 2009 to February 2024 and by reviewing the bibliographies of key references to identify important literature related to combining SBRT with third-generation TKIs in oligometastatic EGFR-mutated NSCLC.

Key Content and Findings

This review aimed to assess the viability of combining SBRT and EGFR-TKIs in oligometastatic EGFR-mutated NSCLC. Current clinical trials suggest that the combined therapies have better progression free survival (PFS) when using SBRT as either concurrent with EGFR-TKIs or consolidated with EGFR-TKIs. Furthermore, research with third-generation EGFR-TKIs and SBRT combinations has demonstrated tolerable toxicity levels without significant additional adverse effects as compared to prior therapies. However, further clinical trials are required to establish its effectiveness.

Conclusions

The combined approach of SBRT and TKIs can effectively impede the progression of oligometastatic NSCLC in patients harboring EGFR mutations and, most notably, can prolong progression-free survival rates. However, the feasibility of combining SBRT with third-generation TKIs in clinical trials remains unclear.

Non-small cell lung cancer: an update on emerging EGFR-targeted therapies

INTRODUCTION

Current research in EGFR-mutated NSCLC focuses on the management of drug resistance and uncommon mutations, as well as on the opportunity to extend targeted therapies' field of action to earlier stages of disease.

AREAS COVERED

We conducted a review analyzing literature from the PubMed database with the aim to describe the current state of art in the management of EGFR-mutated NSCLC, but also to explore new strategies under investigation. To this purpose, we collected recruiting phase II-III trials registered on Clinicaltrials.govand conducted on EGFR-mutated NSCLC both in early and advanced stage.

EXPERT OPINION

With this review, we want to provide an exhaustive overview of current and new potential treatments in EGFR-mutated NSCLC, with emphasis on the most promising newly investigated strategies, such as association therapies in the first-line setting involving EGFR-TKIs and chemotherapy (FLAURA2) or drugs targeting different driver pathways (MARIPOSA). We also aimed at unearthing challenges to achieve in this field, specifically the need to fully exploit already available compounds while developing new ones, the management of new emerging toxicities and the necessity to improve our biological understanding of the disease to design trials with a solid scientific rationale and to allow treatment personalization such in case of uncommon mutations.

Management of oligometastatic and oligoprogressive epidermal growth factor receptor mutated non-small cell lung cancer patients: state of the art of a combined approach

Recently, the development of targeted therapy approaches such as those based on tyrosine kinase inhibitor (TKI) greatly improved the clinical outcomes of patients affected by oncogene addicted advanced non-small cell lung cancer (NSCLC). Similarly, the improvement of radiation therapy techniques has permitted to deliver high radiation doses to a limited number of metastatic target lesions (oligopersistent or oligoprogressive), with limited high-dose normal tissue exposure that leads to low severe toxicity rates. The aim of this narrative review was to provide an overview of the currently established definition of oligometastatic and oligoprogressive disease, to define first line and subsequent lines targeted therapies and the role of consolidative non-invasive local ablative treatments (LATs) in these settings. The potential benefit of local treatment (LT) such as radiotherapy (RT) or surgery might be represented by an overall reduction of switching to subsequent systemic treatments lowering the risk of further systemic dissemination. Further randomized clinical trials will clarify the role of LT and their correct timing in relation to systemic targeted therapies.

Prognostic implications of combining EGFR-TKIs and radiotherapy in Stage IV lung adenocarcinoma with 19-Del or 21-L858R mutations: A real-world study

OBJECTIVE

To elucidate the potential benefits of combining radiotherapy and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for individuals with Stage IV lung adenocarcinoma (LUAD) harboring either exon 19 deletion (19-Del) or exon 21 L858R mutation (21-L858R).

METHODS

In this real-world retrospective study, 177 individuals with Stage IV LUAD who underwent EGFR-TKIs and radiotherapy at Shandong Cancer Hospital from June 2012 to August 2017 were included. The main focus of this real-world study was overall survival (OS).

RESULTS

The clinical characteristics of patients with Stage IV LUAD harboring 19-Del were similar to those harboring 21-L858R (p > 0.05). Overall, the patients had a median OS (mOS) of 32.0 months (95% confidence interval [CI]: 28.6-35.5). Subsequently, multivariate analysis indicated that both EGFR mutations and thoracic radiotherapy were independent predictors of OS (p = 0.001 and 0.013). Furthermore, subgroup analysis highlighted a longer OS for the 19-Del group compared to the 21-L858R group, especially when EGFR-TKIs were combined with bone metastasis or thoracic radiotherapy (mOS: 34.7 vs. 25.1 months and 51.0 vs. 29.6 months; p = 0.0056 and 0.0013, respectively). However, no significant differences were found in OS when considering patients who underwent brain metastasis radiotherapy (mOS: 34.7 vs. 25.1 months; p = 0.088).

CONCLUSIONS

Patients with Stage IV LUAD harboring 19-Del experience a notably prolonged OS following combined therapy with EGFR-TKIs and radiotherapy, while this OS benefit is observed despite the absence of substantial differences in the clinical characteristics between the 19-Del and 21-L858R groups.

Radiation pneumonitis after concurrent aumolertinib and thoracic radiotherapy in EGFR-mutant non-small cell lung cancer patients

BACKGROUND

The superior efficacy of concurrent thoracic radiotherapy (TRT) and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has been proven in locally advanced and advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, the high incidence of radiation pneumonitis (RP) reduced by concurrent TRT and TKIs has attracted widespread attention. Thus, this study was designed to investigate the rate and risk factors for RP in EGFR-positive NSCLC patients simultaneously treated with aumolertinib and TRT.

METHODS

We retrospectively evaluated stage IIIA-IVB NSCLC patients treated with concurrent aumolertinib and TRT between May 2020 and December 2022 at Shandong Cancer Hospital and Institute, Shandong, China. RP was diagnosed by two senior radiologists and then graded from 1 to 5 according to the Common Terminology Criteria for Adverse Events v5.0. All risk factors were evaluated by univariate and multivariate logistic regression analyses.

RESULTS

A total of 49 patients were included, the incidence of grade ≥ 2 RP was 42.9%. Grade 2 and 3 RP were observed in 28.6% and 14.3% of patients, respectively. Grade 4 to 5 RP were not observed. the gross total volume (GTV) ≥ 21 ml and ipsilateral lung V20 ≥ 25% were risk factors for RP. The median progression-free survival (PFS) in the first-line therapy group and second-line therapy group were 23.5 months and 17.2 months, respectively (p = 0.10).

CONCLUSIONS

Better local control is achieved with concurrent TRT and aumolertinib, and special attention should be given to controlling ipsilateral lung V20 and GTV to reduce the risk of RP.

Investigation of Gastrointestinal Toxicities Associated with Concurrent Abdominal Radiation Therapy and the Tyrosine Kinase Inhibitor Sunitinib in a Mouse Model

Tyrosine kinase inhibitors (TKIs) may be combined with radiation therapy (RT) to enhance tumor control; however, increased incidences of gastrointestinal (GI) toxicity have been reported with this combination. We hypothesize that toxicity is due to compromised intestinal healing caused by inhibition of vascular repair and proliferation pathways. This study explores underlying tissue toxicity associated with abdominal RT and concurrent sunitinib in a mouse model. Four groups of CD-1 mice were treated with 12 Gy abdominal RT, oral sunitinib, abdominal RT + sunitinib, or sham treatment. Mice received oral sunitinib or the vehicle via gavage for 14 days. On day 7, mice were irradiated with 12 Gy abdominal RT or sham treated. Mice were euthanized on day 14 and intestinal tract was harvested for semiquantitative histopathologic evaluation and immunohistochemical quantification of proliferation (Ki67) and vascular density (CD31). Non-irradiated groups had stable weights while abdominal irradiation resulted in weight loss, with mice receiving RT + SUN having greater weight loss than mice receiving RT alone. Semiquantitative analysis showed significant increases in inflammation in irradiated groups. The difference in the density of CD31+ cells was significantly increased in RT alone compared to SUN alone. Ki67+ density was not significant. In summary, we identify a lack of angiogenic response in irradiated GI tissues when abdominal RT is combined with a TKI, which may correlate with clinical toxicities seen in canine and human patients receiving combined treatment.

Treatment-Related Pneumonitis of EGFR Tyrosine Kinase Inhibitors Plus Thoracic Radiation Therapy in Patients With Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

Thoracic radiation therapy (RT) for non-small cell lung cancers may overcome resistance to tyrosine kinase inhibitors (TKIs). However, the risk of severe treatment-related pneumonitis (TRP) is a major concern, and the results of the combined treatment remain controversial. Therefore, we aimed to systematically review existing publications and provide a meta-analysis of TRP from a combined therapy of thoracic RT and TKIs. A systematic literature review was performed using the PubMed-MEDLINE and Embase databases to identify eligible publications. The number of severe TRP cases of grade 3 or higher was extracted and then analyzed by fixed or randomized model meta-analysis. Heterogeneity tests were performed using the I² and τ² statistics. Subgroup analyses were conducted on the types of RT and the sequence of the combined treatment. Our literature search identified 37 eligible studies with 1143 patients. Severe TRP occurred in 3.8% (95% CI, 1.8%-6.5%) of patients overall, and fatal pneumonitis occurred rarely in 0.1% (95% CI, 0.0%-0.3%). In the subgroup analysis, the severe TRP proportion was 2.3% (95% CI, 1.0%-4.1%) for patients under definitive (chemo)RT (19 studies, n = 702) versus 2.9% (95% CI, 1.3%-5.1%) for patients who received local stereotactic body RT or palliative RT (15 studies, n = 361). The severe TRP rate was 4.9% (95% CI, 2.4%-8.1%) for concurrent TKI and RT (26 studies, n = 765), which was significantly higher than TRP of 0.4% (95% CI, 0.0%-3.1%) for sequential therapy (6 studies, n = 200). Our meta-analysis showed that combined thoracic RT and epidermal growth factor receptor-TKI therapy has an acceptable risk of severe TRP and rare mortality in patients with non-small cell lung cancers. Concurrent treatment is less tolerable and should be administered with caution. Further investigations using osimertinib are required as the data on its effects are limited.

Targeted treatment for unresectable EGFR mutation-positive stage III non-small cell lung cancer: Emerging evidence and future perspectives

Epidermal growth factor receptor (EGFR) mutations are detected in up to one third of patients with unresectable stage III non-small cell lung cancer (NSCLC). The current standard of care for unresectable stage III NSCLC is consolidation durvalumab for patients who have not progressed following concurrent chemoradiotherapy (the 'PACIFIC regimen'). However, the benefit of immunotherapy, specifically in patients with EGFR mutation-positive (EGFRm) tumors, is not well characterized, and this treatment approach is not recommended in these patients, based on a recent ESMO consensus statement. EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated significant improvements in patient outcomes in EGFRm metastatic NSCLC. The benefits of these agents have also translated to patients with EGFRm early-stage resectable disease as adjuvant therapy. The role of EGFR-TKIs has yet to be prospectively characterized in the unresectable setting. Preliminary efficacy signals for EGFR-TKIs in unresectable EGFRm stage III NSCLC have been reported from a limited number of subgroup and retrospective studies. Several clinical trials are ongoing assessing the safety and efficacy of EGFR-TKIs in this patient population. Here, we review the current management of unresectable EGFRm stage III NSCLC. We outline the rationale for investigating EGFR-TKI strategies in this setting and discuss ongoing studies. Finally, we discuss the evidence gaps and future challenges for treating patients with unresectable EGFRm stage III NSCLC.

Clinical advances in EGFR-TKI combination therapy for EGFR-mutated NSCLC: a narrative review

Background and Objective

Mutations located in epidermal growth factor receptor (EGFR) tyrosine kinase domains have been described as the 'Achilles heel' of non-small cell lung cancer (NSCLC) and can be targeted by epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). However, the clinical benefits of EGFR-TKIs are limited, and drug resistance inevitably occurs in NSCLC patients after long-term exposure to certain drugs. EGFR-TKI combination therapies, including combined targeted therapy, radiotherapy, chemotherapy, and immunotherapy, have shown promise in addressing this issue. This literature review analyzed the rationale and controversies of clinical research related to various EGFR-TKI combination therapies.

Methods

The PubMed database was searched to retrieve articles published from January 1, 2001 to April 15, 2023 using the following Medical Subject Headings (MeSH) terms: "EGFR-mutated non-small cell lung cancer" and "clinical trial". Google Scholar was also reviewed to retrieve additional articles. The search was limited to articles published in English.

Key Content and Findings

In this review, we summarized EGFR-TKI combination therapies, including combined targeted therapy, radiotherapy, chemotherapy, and immunotherapy, most of which have shown efficacy and safety in patients with EGFR-mutated NSCLC. A number of clinical studies with large sample sizes have analyzed the activity and toxicity of combined therapies and explored potential and well-tolerated treatment options.

Conclusions

EGFR mutations have been detected in many NSCLC patients and can be targeted by EGFR-TKIs. However, drug resistance after long-term exposure remains a significant challenge for this type of treatment. Most clinical trials have shown that the combination of EGFR-TKIs and targeted therapy, chemotherapy, radiotherapy or immunotherapy is efficacious and safe in the treatment of EGFR-mutated NSCLC. It should be noted that in some instances, serious adverse events have led to the termination of trials. However, EGFR-TKI combination therapy is indeed an effective approach for the treatment of patients with EGFR-mutated NSCLC and deserves further development.

Recent advances progress of targeted drugs combined with radiotherapy for advanced non-small cell lung cancer: a review

Targeted drug therapy plays an important role in the clinical application of non-small cell lung cancer, especially adenocarcinoma. However, for patients with advanced disease, drug resistance after targeted therapy, unclear target, and other reasons that cannot or do not want surgery, the combination of chemotherapy, radiotherapy, immunity, etc. is often used. The synergistic effect of targeted drugs and radiotherapy in non-small cell lung cancer has shown good clinical efficacy. This article reviews the clinical progress of targeted drug therapy combined with radiotherapy in advanced non-small cell lung cancer in recent years, in order to provide new ideas for further clinical research of this treatment mode.

Impact of thoracic tumor radiotherapy on survival in non-small-cell lung cancer with malignant pleural effusion treated with targeted therapy: Propensity score matching study

BACKGROUND

EGFR-mutant (EGFR-M) and ALK-positive (ALK-P)are common in malignant pleural effusion (MPE) with metastatic non-small-cell lung cancer (NSCLC) (MPE-NSCLC). The impact of thoracic tumor radiotherapy on survival in such patients remains unclear. We aimed to investigate whether thoracic tumor radiotherapy could improve overall survival (OS) in such patients.

METHODS

According to whether or not patients accepted thoracic tumor radiotherapy, 148 patients with EGFR-M or ALK-P MPE-NSCLC treated with targeted therapy were classified into two groups: DT group without thoracic tumor radiotherapy and DRT group with thoracic tumor radiotherapy. Propensity score matching (PSM) was performed to balance clinical baseline characteristics. Overall survival was analyzed by Kaplan-Meier, compared by log-rank test, and evaluated using Cox proportional hazards model.

RESULTS

Median survival time (MST) was 25 months versus 17 months in the DRT group and DT group. The OS rates at 1, 2, 3, 5 years in the DRT group and DT group were 75.0%, 52.8%, 26.8%, 11.1% and 64.5%, 28.4%, 9.2%, 1.8%, respectively (χ2  = 12.028, p = 0.001). Compared with DT group, the DRT group still had better survival after PSM (p = 0.007). Before and after PSM, factors associated with better OS through multivariable analysis were that thoracic tumor radiotherapy, radiotherapy, N0-2 , and ALK-TKIs. Grades 4-5 radiation toxicities were not observed in patients; 8 (11.6%) and 7 (10.1%) out of the DRT group suffered from Grade 3 radiation esophagitis and radiation pneumonitis, respectively.

CONCLUSION

Our results for EGFR-M or ALK-P MPE-NSCLC showed that thoracic tumor radiotherapy may be crucial factor in improving OS with acceptable toxicities. Potential biases should not be neglected: Further randomized controlled trials are necessary to confirm this result.

Re-evaluating the risk factors for radiation pneumonitis in the era of immunotherapy

As one of the common complications of radiotherapy, radiation pneumonia (RP) limits the prognosis of patients. Therefore, better identifying the high-risk factors that lead to RP is essential to effectively prevent its occurrence. However, as lung cancer treatment modalities are being replaced and the era of immunotherapy has arrived, literature that reviews the parameters and mode of radiotherapy, chemotherapy drugs, targeted drugs and current hot immune checkpoint inhibitors related to RP is lacking. This paper summarizes the risk factors for radiation pneumonia by retrieving and analysing previously published literature and the results of large clinical trials. The literature primarily included retrospective analyses, including clinical trials in different periods and a part of the literature review. A systematic literature search of Embase, PubMed, Web of Science, and Clinicaltrials.gov was performed for relevant publications up to 6 Dec. 2022. Search keywords include, but are not limited to, "radiation pneumonia", "pneumonia", "risk factors", "immunotherapy", etc. The factors related to RP in this paper include physical parameters of radiotherapy, including V₅, V₂₀, and MLD; chemoradiotherapy mode and chemotherapy drugs, including paclitaxel and gemcitabine; EGFR-TKI; ALK inhibitors; antiangiogenic drugs; immune drugs and the underlying disease of the patient. We also introduce the possible mechanism of RP. In the future, we hope that this article not only sounds the alarm for clinicians but also helps to identify a method that can effectively intervene and reduce the occurrence of RP, significantly improve the quality of life and prognosis of patients, and more effectively improve the therapeutic effect of radiation therapy.

Incidence of Bone Metastases and Skeletal-Related Events in Patients With EGFR-Mutated NSCLC Treated With Osimertinib

Introduction

Bone metastases are frequent in patients with EGFR-mutated (EGFR+) NSCLC. Skeletal-related events (SREs) are common in these patients; however, no data on SRE in osimertinib-treated patients are reported. We investigated the development of bone metastases and SREs in patients with EGFR+ NSCLC treated with osimertinib.

Methods

This is a retrospective multicenter cohort study that included patients with metastatic EGFR+ NSCLC who were treated with osimertinib between February 2016 and September 2021. Demographics, bone metastases-related outcomes, SREs, treatment efficacy, and overall survival (OS) were collected.

Results

In total, 250 patients treated with osimertinib (43% first line) were included. Of the patients, 51% had bone metastases at initiation of osimertinib. Furthermore, 16% of the patients with bone metastases used bone-targeted agents. Median follow-up from initiation of osimertinib was 23.4 months (95% confidence interval [CI]: 19.9-26.9 mo). During osimertinib treatment, 10% developed new bone metastases or bone progression. Of the patients with bone metastases, 39% had more than or equal to one SREs: 28% developed first SRE before osimertinib treatment, 1% after, and 11% during. Median OS post-bone metastasis was 30.8 months (95% CI: 21.9-39.7). Median OS after first SRE was 31.1 months (95% CI: 15.8-46.5).

Conclusions

Bone metastases and SREs are frequent before and during treatment with osimertinib in EGFR+ NSCLC. Because of these findings and the long OS post-bone metastases, we advocate prescription of bone-targeted agents in these patients and recommend adding bone-specific end points in clinical trials.

EGFR-TKIs plus Stereotactic Body Radiation Therapy (SBRT) for Stage IV Non-small Cell Lung Cancer (NSCLC): a prospective, multicenter, randomized, controlled phase II study

BACKGROUND

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have a significant therapeutic effect in the treatment of advanced non-small-cell lung cancer (NSCLC) with EGFR mutations. However, the acquired resistance greatly limits the survival benefit of EGFR-TKIs for EGFR-mutant NSCLC patients. We aimed to assess the efficacy and safety of stereotactic body radiotherapy (SBRT) plus EGFR-TKIs in these patients.

METHODS

In this prospective, randomized, controlled, phase 2 study, participants were recruited from 4 different hospitals in Wuhan, China. Eligible patients were histologically confirmed to have NSCLC with an EGFR-sensitive mutation (19DEL or 21L858R) and diagnosed at stage IV. Patients who had received first-line EGFR-TKIs treatment including gefitinib, erlotinib, and icotinib and achieved stable disease or partial response were enrolled after three months. Eligible participants were randomly assigned (1:1) to receive SBRT plus EGFR-TKIs or EGFR-TKIs treatment alone. In the combination-group, different tumor sites were irradiated at doses ranging from 30-50Gy in five fractions. Considering the short duration of SBRT, the TKIs were continued during the radiotherapy. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS) and safety. This study was registered at ClinicalTrials.gov, with the registration number of NCT03595644.

RESULTS

Between May 4, 2018 and Dec 20, 2019, 74 patients were screened, of whom 62 patients were enrolled and randomized. The study was closed early with 62/72 patients due to slow accrual. The enrolled patients were randomly assigned to receive SBRT plus EGFR-TKI(n=31) or EGFR-TKI alone (n=31). One patient who was randomized to the SBRT plus EGFR-TKI group refused to receive SBRT during the treatment, and, 61 patients were included the modified intention-to-treat (mITT) analysis, with 30 in the SBRT plus EGFR-TKI and 31 in the EGFR-TKI group. As of the clinical cutoff date (Feb 14, 2022), the median follow-up was 29.4 months (IQR 6.9-38.9). The median PFS of the EGFR-TKI group and SBRT combination group was 9.0 vs 17.6 months (hazard ratio [HR]=0.52, 95% confidence interval [95%CI], 0.31-0.89, P=0.016). Meanwhile, the median OS was 23.2 vs 33.6 months (HR [95%CI], 0.53(0.30-0.95); P= 0.026). There was no grade 3 or greater toxicity observed in either group, the grade 2 adverse events were 50% in the EGFR-TKIs+SBRT group while the percentage was 45.2% in the EGFR-TKIs+SBRT group.

CONCLUSIONS

The addition of SBRT significantly delayed the onset of acquired resistance to EGFR-TKIs and prolonged the PFS and OS of patients. Radiotherapy of the primary lesion alone might be superior to metastatic sites. Further confirmatory studies are needed to confirm our findings.

Locally Advanced Lung Cancer

Consolidation immunotherapy after concurrent chemoradiation has improved five-year survival rates in unresectable, locally advanced lung cancer, but disease progression and treatment personalization remain challenges. New treatment approaches with concurrent immunotherapy and consolidative novel agents are being investigated and show promising efficacy data, but at the risk of additive toxicity. Patients with PD-L1 negative tumors, oncogenic driver mutations, intolerable toxicity, or limited performance status continue to require innovative therapies. This review summarizes historical data that galvanized new research efforts, as well as ongoing clinical trials that address the challenges of current therapeutic approaches for unresectable, locally advanced lung cancer.

Survival benefit of thoracic radiotherapy plus EGFR-TKIs in patients with non-oligometastatic advanced non-small-cell lung cancer: a single-center retrospective study

Objectives:

The study aims to evaluate the efficacy and safety of thoracic radiotherapy in epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-treated patients with stage IV non-small-cell lung cancer (NSCLC).

Methods:

Patients with non-oligometastatic NSCLC harboring EGFR mutations were recruited. All patients received the first-generation TKI treatment with or without radiotherapy. The irradiated sites included primary and/or metastatic lesions. Of all the patients who underwent thoracic radiotherapy, some received radiotherapy before EGFR-TKI resistance, others received radiotherapy after progressive disease.

Results:

No statistically significant difference was observed in progression-free survival (PFS) (median 14.7 versus 11.2 months, p = 0.075) or overall survival (OS) (median 29.6 versus 40.6 months, p = 0.116) between patients treated with EGFR-TKIs alone and those with additional radiotherapy to any sites. However, EGFR inhibitors with thoracic radiation significantly improved OS (median 47.0 versus 31.0 months, p < 0.001) but not PFS (median 13.9 versus 11.9 months, p = 0.124). Moreover, longer PFS (median 18.3 versus 8.5 months, p < 0.001) was achieved in the preemptive thoracic radiation cohort than in the delayed thoracic radiation cohort. However, OS was similar between the two cohorts (median 40.6 versus 52.6 months, p = 0.124). The lower incidence rate of grade 1–2 pneumonitis occurred in preemptive radiation cohort (29.8% versus 75.8%, p < 0.001).

Conclusion:

Non-oligometastatic NSCLC patients with EGFR mutations benefited from thoracic radiotherapy while using EGFR inhibitors. Preemptive thoracic radiotherapy could be a competitive first-line therapeutic option due to superior PFS and favorable safety.

Chemoradiotherapy for untreated Masaoka-Koga stage IVB thymic carcinoma: a single-center retrospective study

BACKGROUND

Thymic carcinoma (TC) is a rare type of a malignant tumor. The optimal treatment for Masaoka-Koga stage IVB TC patients is controversial due to the rarity of the disease. Chemotherapy is still the preferred option, but the outcomes are unsatisfactory. Whether radiotherapy combined with chemotherapy could improve prognosis remains unclear.

METHODS

Untreated stage IVB TC patients who have received first-line chemotherapy were included in the present study. The patients who have undergone surgery were excluded. The primary outcomes were objective response rate (ORR) and progression-free survival (PFS).

RESULTS

Sixty-seven patients were included in the study. A total of 31 patients received chemoradiotherapy (ChemoRT cohort), and the remaining 36 patients only received chemotherapy (Chemo cohort). The median follow-up period was 40.3 months. The ORR for the ChemoRT and Chemo cohorts was 61.3 and 27.8%, respectively (P = 0.006). Furthermore, PFS (P = 0.003) and OS (P = 0.046) were significantly superior in the ChemoRT cohort. Radiotherapy maintained a significant favorable effect on PFS in multivariate analysis (P = 0.014), but the effect on OS was insignificant (P = 0.249). There was no advantage in PFS (P = 0.302) in the ChemoRT cohort in patients who received < 4 cycles of chemotherapy. In contrast, radiotherapy significantly improved PFS (P = 0.005) in patients who received ≥ 4 cycles of chemotherapy.

CONCLUSIONS

Chemoradiotherapy used as the first-line treatment improved ORR and PFS in Masaoka-Koga stage IVB TC patients. Patients receiving more cycles of chemotherapy may have a better chance to benefit from chemoradiotherapy.

Dyspnea in patients with stage IV non-small cell lung cancer: a population-based analysis of disease burden and patterns of care

Background

Patients with metastatic non-small cell lung cancer (NSCLC) experience significant morbidity with dyspnea being a common symptom with a prevalence of 70%. The objective of this study was to determine factors associated with a moderate-to-severe dyspnea score based on the Edmonton Symptom Assessment System (ESAS), as well as resultant patterns of intervention and factors correlated to intervention receipt.

Methods

Using health services administrative data, we conducted a population-based study of all patients diagnosed with metastatic NSCLC treated from January 2007 to September 2018 in the province of Ontario. The primary outcomes of interest are the prevalence of moderate-to-severe dyspnea scores, and the receipt of dyspnea-directed intervention. Differences in baseline characteristic between moderate-to-severe dyspnea and low dyspnea score cohorts were assessed by comparative statistics. Predictors of intervention receipt for patients with moderate-to-severe dyspnea scores were estimated using multivariable modified Poisson regression.

Results

The initial study cohort included 13,159 patients diagnosed with metastatic NSCLC and of these, 9,434 (71.7%) reported a moderate-to-severe dyspnea score. Compared to patients who did not report moderate-to-severe dyspnea scores, those who reported a moderate-to-severe dyspnea score were more likely to complete a greater number of ESAS surveys, be male, have a higher Elixhauser comorbidity index (ECI) score, and receive subsequent systemic therapy after diagnosis. Most patients with a moderate-to-severe dyspnea score received intervention (96%), of which the most common were palliative care management (87%), thoracic radiotherapy (56%) and thoracentesis (37%). Multivariable regression identified older patients to be less likely to undergo pleurodesis. Thoracentesis was less common for patients living in rural and non-major urban areas, lower income areas, and earlier year of diagnosis. Receipt of thoracic radiotherapy was less common for older patients, females, those with ECI ≥4, patients living in major urban areas, and those with later year of diagnosis. Finally, palliative care referrals were less frequent for patients with ECI ≥4, age 60-69, residence outside of major urban areas, earlier year of diagnosis, and lower income areas.

Conclusions

Dyspnea is a prevalent symptom amongst patients with metastatic NSCLC. Subpopulations of patients with moderate-to-severe dyspnea scores were in which inequities may exist in access to care that require further attention and evaluation.

Review: Mechanisms and perspective treatment of radioresistance in non-small cell lung cancer

Radiotherapy is the major treatment of non-small cell lung cancer (NSCLC). The radioresistance and toxicity are the main obstacles that leading to therapeutic failure and poor prognosis. Oncogenic mutation, cancer stem cells (CSCs), tumor hypoxia, DNA damage repair, epithelial-mesenchymal transition (EMT), and tumor microenvironment (TME) may dominate the occurrence of radioresistance at different stages of radiotherapy. Chemotherapy drugs, targeted drugs, and immune checkpoint inhibitors are combined with radiotherapy to treat NSCLC to improve the efficacy. This article reviews the potential mechanism of radioresistance in NSCLC, and discusses the current drug research to overcome radioresistance and the advantages of Traditional Chinese medicine (TCM) in improving the efficacy and reducing the toxicity of radiotherapy.

Non-Small Cell Lung Cancer with Malignant Pleural Effusion May Require Primary Tumor Radiotherapy in Addition to Drug Treatment

PURPOSE

The impact of primary tumour radiotherapy on the prognosis for non-small-cell lung cancer (NSCLC) with controlled malignant pleural effusion (MPE-C) (MPE-C-NSCLC) is unclear. This study aimed to analyze the efficacy and safety of primary tumor radiotherapy in patients with MPE-C-NSCLC.

PATIENTS AND METHODS

A total of 186 patients with MPE-C-NSCLC were enrolled and divided into two groups. The patients in the D group were treated with only drugs. Those in the RD group were treated with drugs plus primary tumour radiotherapy. The Kaplan-Meier method was used for survival analysis, and the Log rank test was used for between-group analysis and univariate prognostic analysis. The Cox proportional hazards model was used to perform multivariate analyses to assess the impacts of factors on survival. Propensity score matching (PSM) was matched based on clinical characteristics, systematic drug treatment and drug response to further adjust for confounding factors.

RESULTS

The overall survival (OS) rates at 1, 2, and 3 years for the RD group and D group were 54.4%, 26.8%, and 13.3% and 31.1%, 11.5%, and 4.4%, respectively; the corresponding MSTs were 14 months and 8 months, respectively (χ 2=15.915, p<0.001). There was a significant difference in survival by PSM (p=0.027).Before PSM, multivariate analysis showed that metastasis status (organ≤3 and metastasis≤5), primary tumour radiotherapy, chemotherapy cycles≥4, and drug best response (CR+PR) were independent predictors of prolonged OS. After PSM, primary tumour radiotherapy and drug best response (CR+PR) were independent predictors of prolonged OS were still independent predictors of prolonged OS. There were no grade 4-5 radiation toxicities.

CONCLUSION

For MPE-C-NSCLC, the response of systemic drug treatment plays a crucial role in survival outcomes, and we also should pay attention to primary tumour radiotherapy in addition to systematic drug treatment.

Effect of thoracic radiotherapy dose on the prognosis of advanced lung adenocarcinoma harboring EGFR mutations

Background

The aim of this study was to investigate the effects of different thoracic radiotherapy doses on OS and incidence of radiation pneumonia which may provide some basis for optimizing the comprehensive treatment scheme of these patients with advanced EGFR mutant lung adenocarcinoma.

Methods

Data from 111 patients with EGFR-mutant lung adenocarcinoma who received thoracic radiotherapy were included in this retrospective study. Overall survival (OS) was the primary endpoints of the study. Kaplan–Meier method was used for the comparison of OS. The Cox proportional-hazard model was used for the multivariate and univariate analyses to determine the prognostic factors related to the disease.

Results

The mOS rates of the patients, who received radiotherapy dose scheme of less than 50 Gy, 50–60 Gy (including 50 Gy), and 60 Gy or more were 29.1 months, 34.4 months, and 51.0 months, respectively (log-rank P = 0.011). Although trend suggested a higher levels of pneumonia cases with increasing radiation doses, these lack statistical significance (χ2 = 1.331; P = 0.514). The multivariate analysis showed that the thoracic radiotherapy dose schemes were independently associated with the improved OS of patients (adjusted hazard ratio [HR], 0.606; 95% CI, 0.382 to 0.961; P = 0.033).

Conclusions

For the patients with advanced EGFR-mutant lung adenocarcinoma, the radical thoracic radiotherapy dose scheme (≥ 60 Gy) could significantly prolong the OS of patients during the whole course management.

Drivers of Radioresistance in Prostate Cancer

Prostate cancer (PCa) is the second most commonly diagnosed cancer worldwide. Radiotherapy remains one of the first-line treatments in localised disease and may be used as monotherapy or in combination with other treatments such as androgen deprivation therapy or radical prostatectomy. Despite advancements in delivery methods and techniques, radiotherapy has been unable to totally overcome radioresistance resulting in treatment failure or recurrence of previously treated PCa. Various factors have been linked to the development of tumour radioresistance including abnormal tumour vasculature, oxygen depletion, glucose and energy deprivation, changes in gene expression and proteome alterations. Understanding the biological mechanisms behind radioresistance is essential in the development of therapies that are able to produce both initial and sustained response to radiotherapy. This review will investigate the different biological mechanisms utilised by PCa tumours to drive radioresistance.

Ablative Radiotherapy as a Strategy to Overcome TKI Resistance in EGFR-Mutated NSCLC

Simple Summary

Most patients with EGFR-mutated NSCLC who receive treatment with targeted therapy will eventually develop resistance, meaning the therapy will lose its efficacy. Prior studies have shown a benefit to continuing to treat patients on TKI therapy despite limited progression of one or more sites of metastatic disease in EGFR-mutated NSCLC. Based on the data reviewed here, the use of radiation therapy to sites of disease progression is both efficacious and carries a low risk for side effects, with the added benefit of allowing patients to continue on TKI therapy.

Abstract

Tyrosine kinase inhibitor (TKI) therapy is the recommended first-line treatment for metastatic non-small-cell lung cancer (NSCLC) positive for epidermal growth factor receptor (EGFR) gene mutation. However, most individuals treated with TKI therapy for EGFR-mutant NSCLC will develop tumor resistance to TKI therapy. Therapeutic strategies to overcome TKI resistance are the topic of several ongoing clinical trials. One potential strategy, which has been explored in numerous trials, is the treatment of progressive sites of disease with stereotactic body radiation treatment (SBRT) or stereotactic radiosurgery (SRS). We sought to review the literature pertaining to the use of local ablative radiation therapy in the setting of acquired resistance to TKI therapy and to discuss stereotactic radiation therapy as a strategy to overcome TKI resistance.

Pulmonary toxicity in driver gene positive non-small cell lung cancer therapy

Molecular targeted therapy significantly improved the therapeutic efficacy in non-small cell lung cancer (NSCLC) patients with driver gene mutations but also with new toxicity profiles. Although most patients treated with these drugs developed relatively controllable toxicity, significant pulmonary toxicity events, including interstitial lung disease, occurred in a small proportion of patients and can lead to discontinuation or even be life-threatening. Pulmonary toxicity associated with these anti-tumor drugs is a problem that cannot be ignored in clinical practice. The prompt diagnosis of drug-related lung injury and the consequent differential diagnosis with other forms of pulmonary disease are critical in the management of pulmonary toxicity. Current knowledge of the pathophysiology and management of pulmonary toxicity associated with these targeted drugs is limited, and participants should be able to identify and respond to the development of drug-induced pulmonary toxicity. This review offers information about the potential pathogenesis, risk factors and management for the development of these events based on the available literature. This review focused on pulmonary toxicities in driver gene-positive NSCLC therapy by describing the related adverse events to promote the awareness and management of this important toxicity related to antitumor-targeted therapy.

The Value of Radiotherapy for Advanced Non-Small Cell Lung Cancer With Oncogene Driver-Mutation

Due to the widespread use of tyrosine kinase inhibitors (TKIs), which have largely supplanted cytotoxic chemotherapy as the first-line therapeutic choice for patients with advanced non-small cell lung cancer (NSCLC) who have oncogene driver mutations, advanced NSCLC patients with oncogene driver mutations had much long median survival. However, TKIs’ long-term efficacy is harmed by resistance to them. TKIs proved to have a limited potential to permeate cerebrospinal fluid (CSF) as well. Only a small percentage of plasma levels could be found in CSF at usual doses. Therefore, TKIs monotherapy may have a limited efficacy in individuals with brain metastases. Radiation has been demonstrated to reduce TKIs resistance and disrupt the blood-brain barrier (BBB). Previous trials have shown that local irradiation for bone metastases might improve symptoms, in addition, continuous administration of TKIs combined with radiotherapy was linked with beneficial progression-free survival (PFS) and overall survival (OS) for oligometastasis or bone metastasis NSCLC with oncogene driver mutations. The above implied that radiotherapy combined with targeted therapy may have a synergistic impact in patients with advanced oncogene driver-mutated NSCLC. The objective of this article is to discuss the value of radiotherapy in the treatment of those specific individuals.

Local Therapy Combined With First-Line EGFR Tyrosine Kinase Inhibitor Achieves Favorable Survival in Patients With EGFR-Mutant Metastatic Non-Small Cell Lung Cancer

BACKGROUND

EGFR tyrosine kinase inhibitor (TKI) is recommended as the first-line therapy for patients with EGFR-mutant metastatic non-small cell lung cancer (NSCLC). Yet, resistance often occurs in 1 year after therapy and most progressions occur at the initial sites of disease. Addition of local therapy to the first-line TKI therapy may delay the progression and provide survival benefit to the patients.

METHODS

From 2010 to 2017, metastatic NSCLC patients with EGFR activating mutations who received first-line TKI and relatively radical local therapy (RRLT) were reviewed. RRLT was defined as local curative therapy to the main site or any intensity of local therapy to all sites of disease. The Kaplan-Meier method and log-rank test were used for survival estimation and comparison.

RESULTS

A total of 45 patients were included in this retrospective study with a median follow-up of 48.0 months. The median progression-free survival (PFS) and overall survival (OS) was 17.0 months (95% confidence interval [CI]: 14.6-19.3) and 55.0 months (95% CI: 49.3-60.6), respectively. Univariate analysis indicated that age ⩽ 60 years (P = .019), first-line TKI duration ⩾ 10 months (P = .028), and accumulated TKI duration ⩾ 20 months (P = .016) were significantly associated with favorable OS. Among the 36 patients who progressed during the follow-up, 55.8% of the progressions occurred at the new sites. RRLT combined with TKI did not show any severe toxicity to the patients.

CONCLUSIONS

Combined application of RRLT and first-line TKI may improve the survival and alter the pattern of failure for metastatic NSCLC patients with EGFR activating mutations.

Efficacy and safety of recombinant human endostatin during peri-radiotherapy period in advanced non-small-cell lung cancer

Background: This study aimed to retrospectively investigate the efficacy and safety of recombinant human endostatin (Rh-endostatin) combined with radiotherapy in advanced non-small-cell lung cancer (NSCLC). Methods: Patients with unresectable stage III and IV NSCLC who treated with radiotherapy were enrolled. Patients who received Rh-endostatin infusion throughout the whole peri-radiotherapy period formed the Endostar group, and those who received no Rh-endostatin infusion were the control group. Results: The median progression-free survival was 8.0 and 4.4 months (hazard ratio: 0.53; 95% CI: 0.32-0.90; p = 0.019) and median overall survival was 40.0 and 13.1 months (hazard ratio: 0.53; 95% CI: 0.28-0.98; p = 0.045) for the Endostar and control groups, respectively. The Endostar group exhibited a numerically lower rate of radiation pneumonitis relapse, radiation pneumonitis death and pulmonary fibrosis. Conclusion: Rh-endostatin infusion throughout the peri-radiotherapy period enhanced radiosensitivity and showed better survival outcomes and a tendency toward fewer radiation-related pulmonary events in patients with NSCLC.

Lung squamous cell carcinoma with rare epidermal growth factor receptor mutation G719X: a case report and literature review

Asians who develop non-small cell lung cancer (NSCLC) have a chance of approximately 50% of harboring the epidermal growth factor receptor (EGFR) mutation. The G719X mutation in EGFR has 3 subtypes (i.e., G719A, G719C, or G719S), all of them being classified as uncommon EGFR mutations. The EGFR mutation G719X is most often associated with lung adenocarcinoma. Conversely, its occurrence in lung squamous cell carcinoma is rare. Its response to tyrosine kinase inhibitor (TKI) treatment remains unknown. A 50-year-old Asian male with no smoking history was admitted to our hospital (Affiliated Hospital of Qingdao University) with an irritating dry cough and 1 month of progressive dyspnea. The patient was diagnosed with lung squamous cell carcinoma (cT4N3M0, stage IIIC). Lung biopsy revealed the presence of EFGR G719X mutation. The patient received a tracheobronchial stent, targeted therapy, chemotherapy, seed implantation and radiotherapy, and survived for 25.4 months following diagnosis. It is crucial that gene mutation analysis is performed in non-smoking male squamous cell carcinoma patients. Compared to lung adenocarcinoma patients with rare G719X mutation, this lung squamous cell carcinoma patient with G719X-mutant tumor had a higher sensitivity to 2^nd-generation EGFR-TKI treatment, but similar progression-free survival. Importantly, the patient clearly benefited from the used comprehensive treatment plan. This article seeks to shed light on the treatment of lung squamous cell carcinoma patients with the uncommon EGFR G719X mutation.

AZD9291-resistant non-small cell lung cancer cell-derived exosomal lnc-MZT2A-5:1 induces the activation of fibroblasts

Background

AZD9291 resistance is still a challenge in the treatment of non-small cell lung cancer (NSCLC) and fibroblasts in the tumor microenvironment (TME) play a key role in the malignant phenotype of NSCLC. The study aimed to investigate the role of exosomes derived from AZD9291-resistant cells on the phenotypes of lung fibroblasts and the underlying mechanism.

Methods

The supernatants and exosomes of wild type and AZD9291-resistant NSCLC (H1975/PC9) cells were collected, and co-cultured with lung fibroblasts (MRC-5 cells) respectively. Transwell and quantitative real-time PCR (qRT-PCR) assays were used to evaluate migration and inflammation levels. Exosomes were collected by ultracentrifugation, and identified by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and western blots. Microarray was used to screen dysregulated exosomal lncRNAs from the resistant cells. Candidate lncRNAs were selected by bioinformatical annotation of their target genes and verified by qRT-PCR. The target lncRNA was then selected for further confirmation.

Results

Both the supernatant and exosomes from resistant cells significantly promoted the migration of MRC-5 cells, and the exosomes also upregulated mRNA levels of inflammation cytokines. Microarray identified 159 dysregulated exosomal lncRNAs. Fifteen candidate lncRNAs were selected following the biological roles of their target genes. qRT-PCR validation indicated that lnc-MZT2A-5:1 had the highest fold change. Finally, we found that lnc-MZT2A-5:1 could promote the migration ability and inflammation cytokines expression level of MRC-5 cells.

Conclusions

Our study clarified that lnc-MZT2A-5:1 from AZD9291-resistant NSCLC cell lines could promote the activation of MRC-5 cells, thus to uncover a new mechanism for AZD9291 resistance and provide new potential targets for the treatment of NSCLC.

Circular RNA CELF1 drives immunosuppression and anti-PD1 therapy resistance in non-small cell lung cancer via the miR-491-5p/EGFR axis

Aim: To explore the immunoregulatory effects of circ_CELF1 in non-small cell lung cancer (NSCLC).

Methods: The mRNA level of circ_CELF1 in primary tissue samples was analyzed by qRT-PCR. The assays of CCK-8, colony formation, wound healing as well as Transwell were employed for measurement of cancer cell malignant transformation. The murine subcutaneous tumor model was used to assess the tumorigenesis of NSCLC in vivo. The assays of circRNA precipitation, RNA immunoprecipitation, and luciferase reporter were performed to study the relationship between circ_CELF1, miR-491-5p, and EGFR.

Results: circ_CELF1 is upregulated in primary cancer tissues from patients with NSCLC, and a high level of circ_CELF1, is associated with malignant characteristics and poor outcomes of patients with NSCLC. Enforced expression of circ_CELF1 exacerbated the malignant transformation of NSCLC cells. Mechanistically, through directly interacting with miR-491-5p, circ_CELF1 acted as a miRNA sponge that increased the expression of the miR-491-5p target gene EGFR, eventually promoting the progression of NSCLC and increasing cancer resistance to immunotherapy.

Conclusion: Our data demonstrate that upregulation of circ_CELF1 elicits both oncogenic and immunoregulatory effects on the development of NSCLC. We believe that circ_CELF1 can act as a potential therapeutic target for the treatment of NSCLC.

A review on epidermal growth factor receptor's role in breast and non-small cell lung cancer

Epithelial growth factor receptor (EGFR) is a cell surface transmembrane receptor that mediates the tyrosine signaling pathway to carry the extracellular messages inside the cell and thereby alter the function of nucleus. This leads to the generation of various protein products to up or downregulate the cellular function. It is encoded by cell erythroblastosis virus oncogene B1, so called C-erb B1/ERBB2/HER-2 gene that acts as a proto-oncogene. It belongs to the HER-2 receptor-family in breast cancer and responds best with anti-Herceptin therapy (anti-tyrosine kinase monoclonal antibody). HER-2 positive breast cancer patient exhibits worse prognosis without Herceptin therapy. Similar incidence and prognosis are reported in other epithelial neoplasms like EGFR + lung non-small cell carcinoma and glioblastoma (grade IV brain glial tumor). Present study highlights the role and connectivity of EGF with various cancers via signaling pathways, cell surface receptors mechanism, macromolecules, mitochondrial genes and neoplasm. Present study describes the EGFR associated gene expression profiling (in breast cancer and NSCLC), relation between mitrochondrial genes and carcinoma, and several in vitro and in vivo models to screen the synergistic effect of various combination treatments. According to this study, although clinical studies including targeted treatments, immunotherapies, radiotherapy, TKi-EGFR combined targeted therapy have been carried out to investigate the synergism of combination therapy; however still there is a gap to apply the scenarios of experimental and clinical studies for further developments. This review will give an idea about the transition from experimental to most advanced clinical studies with different combination drug strategies to treat cancer.

Thoracic surgery improved overall survival in patients with stage IIIB-IV epidermal growth factor receptor-mutant lung adenocarcinoma who received and responded to tyrosine kinase inhibitor treatment

PURPOSE

No large-scale, prospective, randomized study has evaluated the effect of thoracic surgery on patients with unresectable stage IIIB-IV epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma who received and responded to EGFR tyrosine kinase inhibitor (TKI) treatment. Therefore, we designed a propensity-score-matched, nationwide, population-based, cohort study to investigate the effects of thoracic surgery on patients with EGFR-mutant lung adenocarcinoma.

PATIENTS AND METHODS

We included patients with unresectable stage IIIB-IV EGFR-mutant lung adenocarcinoma and categorized them into two groups according to their treatment modalities and compared their outcomes: the case group consisted of patients who underwent thoracic surgery for lung tumors after receiving and responding to EGFR-TKI treatment and the comparison group consisted of patients who received EGFR-TKI treatment alone until tumor progression. Patients in both groups were matched at a ratio of 1:4.

RESULTS

The matching process yielded a final cohort of 1395 patients (279 and 1,116 in the case and comparison groups, respectively) who were eligible for further analysis. According to multivariable Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval [CI]) for thoracic surgery for lung tumors after EGFR-TKI use and tumor response (group 2) compared with EGFR-TKI treatment alone (group 1) was 0.445 (0.351-0.564).

CONCLUSIONS

Thoracic surgery prolonged overall survival in patients with unresectable stage IIIB-IV EGFR-mutant lung adenocarcinoma who received and responded to EGFR-TKI treatment.

Reasonable Timing of Radiotherapy for Stage IV Non-Small-Cell Lung Cancer During Targeted Therapy Based on Tumour Volume Change

Purpose

The aim of this study was to investigate the reasonable timing of radiotherapy for stage IV non-small-cell lung cancer (NSCLC) with EGFR-positive mutations during targeted therapy based on tumour volume change (TVC).

Patients and Methods

Simulation Computed Tomography Scan (SCTS) measurements were taken to test TVC in patients with stage IV NSCLC during targeted therapy at intervals of 10 days. The SCTS measurement was terminated when the tumour volume shrinkage rate in the latter simulation compared with the previous simulation was ≤5% or when the time after treatment was 90 days. Then, primary tumour radiotherapy was performed. Related parameters of the radiotherapy plan were compared between the implementation and simulation plans.

Results

Twenty-seven patients were enrolled in the analysis. After treatment, shrinkage of the primary tumour was observed in all patients, but the rate and speed were inconsistent. The average tumour volume decreased obviously within 40 days and was significantly different every 10 days (P ≤ 0.001). The average volume decreased slowly and tended to be stable (P>0.05) after 40 days. After the termination of SCTSs, 21 patients accepted primary tumour radiotherapy. No patients experienced grade 3+ acute radiation toxicity. The implementation radiotherapy plan was significantly better than that before treatment (all P<0.05) but not better than that on the 40th day after treatment (all P>0.05).

Conclusions

To obtain a high radiation dose and control radiation toxicity, the 40th day after targeted therapy may be a reasonable time to start radiotherapy for stage IV NSCLC with EGFR-positive mutations.

Clinical Trial Registration

https://www.clinicaltrials.gov/ct2/show/NCT03258671, identifier, NCT03258671.

Molecular Mechanism of EGFR-TKI Resistance in EGFR-Mutated Non-Small Cell Lung Cancer: Application to Biological Diagnostic and Monitoring

Non-small cell lung cancer (NSCLC) is the most common cancer in the world. Activating epidermal growth factor receptor (EGFR) gene mutations are a positive predictive factor for EGFR tyrosine kinase inhibitors (TKIs). For common EGFR mutations (Del19, L858R), the standard first-line treatment is actually third-generation TKI, osimertinib. In the case of first-line treatment by first (erlotinib, gefitinib)- or second-generation (afatinib) TKIs, osimertinib is approved in second-line treatment for patients with T790M EGFR mutation. Despite the excellent disease control results with EGFR TKIs, acquired resistance inevitably occurs and remains a biological challenge. This leads to the discovery of novel biomarkers and possible drug targets, which vary among the generation/line of EGFR TKIs. Besides EGFR second/third mutations, alternative mechanisms could be involved, such as gene amplification or gene fusion, which could be detected by different molecular techniques on different types of biological samples. Histological transformation is another mechanism of resistance with some biological predictive factors that needs tumor biopsy. The place of liquid biopsy also depends on the generation/line of EGFR TKIs and should be a good candidate for molecular monitoring. This article is based on the literature and proposes actual and future directions in clinical and translational research.

Thoracic stereotactic body radiation therapy plus first-line tyrosine kinase inhibitors for patients with epidermal growth factor receptor-mutant polymetastatic non-small-cell lung cancer: A propensity-matched retrospective study

The role of thoracic stereotactic body radiation therapy (SBRT) in addition to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant polymetastatic non-small-cell lung cancer (NSCLC) has not been well established. This retrospective study aimed to evaluate the efficacy and safety of EGFR-TKIs with thoracic SBRT for the treatment of this patient group.Polymetastatic NSCLC was defined as having >5 metastatic lesions. Patients with polymetastatic NSCLC harboring positive EGFR mutations after initial TKI therapy for at least 8 weeks were eligible for SBRT between August 2016and August 2019. Eligible patients were treated with thoracic SBRT, and TKIs were administered for the duration of SBRT and continued after SBRT until they were considered ineffective. The control group was treated with TKI monotherapy. Propensity score matching (ratio of 1:4) was used to account for differences in baseline characteristics. Progression-free survival (PFS), overall survival, and treatment safety were evaluated.In total, 136 patients were included in the study population. Among them, 120 patients received TKIs alone, and 16 patients received TKIs with thoracic SBRT. The baseline characteristics did not significantly differ between the two cohorts after propensity score matching. The median PFS was 17.8 months in the thoracic SBRT group and 10.8 months in the control group (P = .033). In the multivariate analysis, a Cox regression model showed that thoracic SBRT was an independent statistically significant positive predictor of improved survival, with a hazard ratio of 0.54 (P = .046). We recorded no severe toxic effects or grade 4 to 5 toxicities.Real-world data demonstrate that thoracic SBRT significantly extends PFS in EGFR-mutant polymetastatic NSCLC patients with tolerable toxicity. Given these results, randomized studies are warranted.

EGFR-mutated stage IV non-small cell lung cancer: What is the role of radiotherapy combined with TKI?

Lung cancer is the leading cause of cancer-related death globally and poses a considerable threat to public health. Asia has the highest prevalence of epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC). Despite the reasonable response and prolonged survival associated with EGFR-tyrosine kinase inhibitor (TKI) therapy, the acquisition of resistance to TKIs remains a major challenge. Additionally, patients with EGFR mutations are at a substantially higher risk of brain metastasis compared with those harboring wild-type EGFR. The role of radiotherapy (RT) in EGFR-mutated (EGFRm) stage IV NSCLC requires clarification, especially with the advent of next-generation TKIs, which are more potent and exhibit greater central nervous system activity. In particular, the feasible application of RT, including the timing, site, dose, fraction, and combination with TKI, merits further investigation. This review focuses on these key issues, and provides a flow diagram with proposed treatment options for metastatic EGFRm NSCLC, aiming to provide guidance for clinical practice.

Targeted therapy moves to earlier stages of non-small-cell lung cancer: emerging evidence, controversies and future challenges

Lung cancer continues to be the leading cause of cancer mortality and a serious health problem despite the numerous advances made in the last decade and the rapid advance of research in this field. In recent years, there has been a decrease in mortality from lung cancer coinciding with the approval times of targeted therapy. To date, targeted therapy has been used in the context of advanced disease in clinical practice, with great benefits in survival and quality of life. The next step will be to incorporate targeted therapy into the treatment of earlier stages of non-small-cell lung cancer, and there is already a randomized trial showing a disease-free survival benefit. However, there are many questions that need to be resolved first. In the present review, the authors discuss the findings of published reports and ongoing clinical trials assessing the role of targeted therapies in nonmetastatic disease.

Perioperative alectinib in a patient with locally advanced anaplastic lymphoma kinase positive non-small cell lung cancer (NSCLC): a case report

We reported a case of locally advanced anaplastic lymphoma kinase (ALK) positive non-small cell lung cancer (NSCLC) patient who received neoadjuvant alectinib therapy. Enhanced computed tomography (CT) scan was performed after the first cycle of alectinib therapy to evaluate the efficacy of neoadjuvant alectinib. Surprisingly, the tumor shrunk 42.2% after one cycle treatment. Partial remission (PR) was achieved without any side effects, although the tumor stage didn’t degrade. Then right upper lobectomy and mediastinal lymph node dissection by video assistant thoracoscopic surgery (VATS) were successfully performed after multi-disciplinary team meeting with the department of respiratory, thoracic surgery, radiotherapy (RT), pathology and radiology. Pathologic evaluation about tumor was assessed by hematoxylin and eosin staining. However, the residual viable tumor cells were 15%, which indicated that major pathologic response (MPR) was not achieved. Next, continually adjuvant alectinib and RT were given because mediastinal station 4R lymphadenectomy excluded with serious tissue adhesion and MPR status was not met. In this case, we presented neoadjuvant alectinib therapy was feasible and well tolerated in locally advanced ALK positive NSCLC, inspiring clinical studies to further assess its clinical implication in treating patients with locally advanced ALK-positive NSCLC. And we also discussed the necessary time of neoadjuvant and adjuvant alectinib in advanced ALK-positive NSCLC.

A Multicenter Retrospective Study on the Prognosis of Stage III Unresectable Mutant Non-Small Cell Lung Cancer With Tyrosine Kinase Inhibitors Therapy

Background

For unresectable stage III non-small cell lung cancer (NSCLC), concurrent chemoradiotherapy is nowadays the standard treatment. Patients with advanced NSCLC harboring driver-gene mutations benefit from Tyrosine Kinase Inhibitors (TKIs) Therapy. In a real-world setting, there is room for exploring the benefit of TKIs in stage III unresectable NSCLC patients with mutation.

Methods

A total of 81 patients from the Jinling Hospital and the Jiangsu Cancer Hospital with stage III unresectable mutant NSCLC applied targeted therapy were enrolled in this retrospective study. Patients with first-line application of TKIs were followed up to gain the situation of surgery qualifications, progression-free survival and overall survival, so as to evaluate the survival prognosis, then whether patients benefit and what kind of patients benefit most from TKI monotherapy treatment or its combination are explored.

Results

The median progression-free survival of involved 81 patients was 13.87 months (95% confidence interval (CI): 11.66-16.08), and the median survival was 41.47 months (95%CI: 20.11-62.83). The 5-year survival rates were 91.0, 80.3, 56.1, 45.5, and 32.5%, respectively. After first-line TKI therapy, seven patients (8.6%) were reevaluated as eligible for surgery and proceeded to surgery. Although no characteristics were found to be statistical prognostic, younger female non-smokers still tended to have a better prognosis with longer progression free survival and overall survival.

Conclusions

TKIs are a viable option for mutant stage III unresectable NSCLC patients who have achieved good clinical benefit from TKI. Patients who cannot tolerate chemoradiotherapy, especially those with driver gene mutations, can choose targeted therapy for first-line treatment.

Reporting of Incidence and Outcome of Bone Metastases in Clinical Trials Enrolling Patients with Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma-A Systematic Review

Bone metastases, occurring in 30-60% of patients with non-small cell lung cancer (NSCLC), are associated with decreased survival, cancer-induced bone pain, and skeletal-related events (SREs). Those with an activating epidermal growth factor mutation (EGFR+) seem to be more prone to develop bone metastases. To gain more insight into bone metastases-related outcomes in EGFR+ NSCLC, we performed a systematic review on Pubmed (2006-2021). Main inclusion criteria: prospective, phase II/III trials evaluating EGFR-tyrosine kinase inhibitors, ≥10 EGFR+ patients included, data on bone metastases and/or bone-related outcomes available. Out of 663 articles, 21 (3176 EGFR+ patients) met the eligibility criteria; 4 phase III (one double blind), 17 phase II trials (three randomized) were included. In seven trials dedicated bone imaging was performed at baseline. Mean incidence of bone metastases at diagnosis was 42%; 3-33% had progression in the bone upon progression. Except for one trial, it was not specified whether the use of bone target agents was permitted, and in none of the trials, occurrence of SREs was reported. Despite the high incidence of bone metastases in EGFR+ adenocarcinoma, there is a lack of screening for, and reporting on bone metastases in clinical trials, as well as permitted bone-targeted agents and SREs.

Thoracic radiotherapy and concurrent almonertinib for unresectable stage III EGFR-mutated non-small-cell lung cancer: a phase 2 study

Background

Concurrent chemo-radiotherapy remains the standard treatment in unresectable stage III non-small-cell lung cancer (NSCLC) patients. Several studies have shown a potential value of concurrent epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) with thoracic radiotherapy in EGFR-mutated population, but a high risk of radiation pneumonitis raised a major concern. This study intends to explore the safety and efficacy of concurrent almonertinib, a new third-generation EGFR-TKI, with radiotherapy in locally advanced EGFR-mutated NSCLC patients.

Methods

Locally advanced NSCLC patients harboring sensitive EGFR mutation will be included in this study. A radiotherapy plan will be made for each patient before treatment, and the lung V20 will be calculated. Patients with lung V20 ≥ 28% were enrolled in induction group (arm A), which almonertinib was given for 2 months followed by concurrent radiotherapy; patients with lung V20 < 28% were enrolled in concurrent group (arm B), which almonertinib was given concurrent with thoracic radiotherapy. The primary endpoint is the incidence of grade ≥ 3 radiation pneumonitis within 6 months post-radiotherapy, and the secondary endpoints are local control rate, progression-free survival, and overall survival.

Discussion

The safety and efficacy of third-generation EGFR-TKI concurrent with thoracic radiotherapy in locally advanced EGFR-mutated NSCLC is still unknown. We propose to conduct this phase 2 study evaluating the safety especially the radiation pneumonitis within 6 months post-radiotherapy. This trial protocol has been approved by the Ethics committee of Hangzhou cancer hospital. The ethics number is HZCH-2020-030.

Trial registration

clinicaltrials.gov, NCT04636593. Registered 19 November 2020 - Retrospectively registered

Impact of Radiotherapy Pattern on the Prognosis of Stage IV Lung Adenocarcinomas Harboring EGFR Mutations

Introduction

The aim of this study was to investigate the role of local radiotherapy in the management of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancers (NSCLCs) treated with EGFR tyrosine kinase inhibitors (TKIs).

Materials and Methods

Patients with stage IV EGFR-mutant NSCLC treated with radiotherapy concomitant to EGFR TKIs from May 2010 to December 2017 were retrospectively identified. Overall survival (OS) was the primary endpoints of the study.

Results

A total of 205 patients were enrolled in the study. One hundred eleven patients received one-time single-site radiotherapy (SSR), and 94 patients received multiple-site radiotherapy (MSR). Patients who received MSR had longer OS (median OS, 40.0 months; 95% confidence interval [CI], 29.6 to 50.4) than those who received SSR (median OS, 28.9 months; 95% CI, 24.3 to 33.5; P=0.031). Thoracic radiotherapy was associated with prolonged median OS (41.7 months, 95% CI, 29.0 to 54.4 vs 27.1 months, 95% CI 22.7 to 31.5; log-rank P<0.001). Multivariate analysis confirmed that thoracic radiotherapy was independently associated with improved OS (adjusted hazard ratio [HR], 0.514; 95% CI 32.3% to 81.8%; P=0.005).

Conclusion

MSR improves survival outcomes in patients with advanced-stage, EGFR-mutant, lung adenocarcinoma, with thoracic radiotherapy having the most significant effect on prognosis.

Systemic Therapy for Mutation-Driven NSCLC

Lung cancer is the leading cause of cancer deaths worldwide, and patients with nonsmall cell lung cancer have traditionally had a poor prognosis. An improved understanding of targetable oncogenic molecular alterations has led to a growing number of effective and first-line therapies in targeted patient populations. This review provides an overview of systemic therapy options available for patients with mutation-driven nonsmall cell lung cancer, as well as a discussion of data regarding safety when combined with radiation therapy.

Primary Tumor Radiotherapy During EGFR-TKI Disease Control Improves Survival of Treatment Naïve Advanced EGFR-Mutant Lung Adenocarcinoma Patients

Background

Whether radiotherapy only for primary lung tumor (RTPLT) after epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy improves survival of treatment naïve advanced EGFR-mutant lung adenocarcinoma (LAD) patients with/without polymetastasis.

Materials and Methods

This was a retrospective, single-center, observational study. Patients with stage IIIB-IV EGFR-mutant LAD with disease control by EGFR-TKI therapy were divided into curative RTPLT, and control, without radiotherapy (WRTPLT) groups.

Results

A total of 138 patients were enrolled; 46 in the RTPLT group and 92 in the WRTPLT group. Amongst them, 37% had oligometastasis, and 26.1% brain metastasis. The RTPLT group had both significantly longer progression-free survival (PFS) (27.5 months [95% CI 18.1–36.9] vs 10.9 months [95% CI 6.3–15.5], P<0.001) and overall survivor (OS) (NR [95% CI NR-NR] vs 38.0 months [95% CI 31.2–44.8], P<0.001), respectively, when compared to the WRTPLT group. In multivariate analysis, the adjusted HR of radiotherapy on PFS was 0.30 (0.19–0.47) and on OS, 0.11 (0.04–0.30). Patients with oligometastasis had significantly longer PFS than those with polymetastasis with an HR of 0.35 (0.14–0.85), P=0.02. Patients with either oligometastasis or polymetastasis had significant longer PFS when undergoing radiotherapy than those without (both P<0.05). An EGFR-TKI to radiotherapy interval <24 weeks seemed more beneficial (P=0.097). Radiation pneumonitis comprised 32 (69.6%), 12 (26.1%), and two (4.3%) cases of common terminology criteria grade I, II, and III, respectively.

Conclusion

Curative RTPLT can prolong survival in patients with LAD following EGFR-TKI disease control, both involving oligometastasis and polymetastasis. RTPLT within 24 weeks after EGFR-TKI initiation appeared to be more beneficial with tolerable radiation pneumonitis.

Management of Oligometastasis and Oligoprogression in Patients with Epidermal Growth Factor Receptor Mutation-Positive NSCLC in the Era of Third-Generation Tyrosine Kinase Inhibitors

This review covers the importance of local consolidative therapy (LCT) in patients with epidermal growth factor receptor (EGFR) mutation-positive with oligometastatic and oligoprogressive non-small-cell lung cancer (NSCLC). With the advent of third-generation EGFR tyrosine kinase inhibitors, a more updated review is necessary. We review the efficacy of LCT, pathophysiological background, and treatment modalities other than radiotherapy. In addition, we also discussed when and how LCT should be applied to patients with oligometastatic and oligoprogressive NSCLC.

Overlap time is an independent risk factor of radiation pneumonitis for patients treated with simultaneous EGFR-TKI and thoracic radiotherapy

Background

The exact rate and relevant risk factors of radiation pneumonitis (RP) for non-small-cell cancer (NSCLC) patients treated with the combination of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and thoracic radiotherapy have not been reported. Thus, this study aimed to investigate the rate and risk factors of RP for EGFR-positive NSCLC patients simultaneously treated with first-generation EGFR-TKI and TRT.

Patients and methods

We retrospectively evaluated NSCLC patients simultaneously treated with first-generation EGFR-TKI and thoracic radiotherapy between January 2012 and December 2019 at Shandong Cancer Hospital and Institute, Shandong, China. RP was diagnosed via computed tomography and was classified according to the Common Terminology Criteria for Adverse Events v5.0. The risk factors of RP were identified using uni- and multivariate analyses.

Results

Of the 67 patients included, 44.78% (30/67) developed grade ≥ 2 RP. Grade ≥ 2 RP occurred within a median of 3.48 (range 1.07–13.6) months. The EGFR-TKI icotinib, ipsilateral lung V30 > 34%, and overlap time of > 20 days between EGFR-TKI and thoracic radiotherapy were identified to be independent predictive factors of grade ≥ 2 RP.

Conclusions

Grade ≥ 2 RP is highly frequent in NSCLC patients simultaneous treated with first-generation EGFR-TKI and thoracic radiotherapy. Icotinib, ipsilateral lung V30 ≤ 34%, and overlap time of ≤ 20 days for EGFR-TKI and thoracic radiotherapy will be helpful to lower the risk of RP in these patients. The addition of thoracic radiotherapy should be cautious, and the treatment strategies can be optimized to reduce the rate of RP for patients treat with simultaneous EGFR-TKI and thoracic radiotherapy.

Knockdown of lncRNA X inactive specific transcript (XIST) radiosensitizes non-small cell lung cancer (NSCLC) cells through regulation of miR-16-5p/WEE1 G2 checkpoint kinase (WEE1) axis

Long non-coding RNA (lncRNA) X inactive specific transcript (XIST) is reported to play an oncogenic role in non-small cell lung cancer (NSCLC). However, the role of XIST in regulating the radiosensitivity of NSCLC cells remains unclear. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expressions of XIST and miR-16-5p in NSCLC in tissues and cells, and Western blot was used to assess the expression of WEE1 G2 checkpoint kinase (WEE1). Cell counting kit-8 (CCK-8), colony formation and flow cytometry assays were used to determine cell viability and apoptosis after NSCLC cells were exposed to different doses of X-rays. The interaction between XIST and miR-16-5p was confirmed by StarBase database, qRT-PCR and dual-luciferase reporter gene assays. TargetScan database was used to predict WEE1 as a target of miR-16-5p, and their targeting relationship was further validated by Western blot, qRT-PCR and dual-luciferase reporter gene assays. XIST was highly expressed in both NSCLC tissue and cell lines, and knockdown of XIST repressed NSCLC cell viability and cell survival, and facilitated apoptosis under the irradiation. MiR-16-5p was a target of XIST, and rescue experiments demonstrated that miR-16-5p inhibitors could reverse the role of XIST knockdown on radiosensitivity in NSCLC cells. WEE1 was validated as a target gene of miR-16-5p, and WEE1 could be negatively regulated by XIST. XIST promotes the radioresistance of NSCLC cells by regulating the expressions of miR-16-5p and WEE1, which can be a novel target for NSCLC therapy.