Efficacy and acquired resistance for EGFR-TKI plus thoracic SBRT in patients with advanced EGFR-mutant non-small-cell lung cancer: a propensity-matched retrospective study

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.

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.

Metastases-directed stereotactic body radiotherapy in combination with targeted therapy or immunotherapy: systematic review and consensus recommendations by the EORTC-ESTRO OligoCare consortium

Stereotactic body radiotherapy (SBRT) for patients with metastatic cancer, especially when characterised by a low tumour burden (ie, oligometastatic disease), receiving targeted therapy or immunotherapy has become a frequently practised and guideline-supported treatment strategy. Despite the increasing use in routine clinical practice, there is little information on the safety of combining SBRT with modern targeted therapy or immunotherapy and a paucity of high-level evidence to guide clinical management. A systematic literature review was performed to identify the toxicity profiles of combined metastases-directed SBRT and targeted therapy or immunotherapy. These results served as the basis for an international Delphi consensus process among 28 interdisciplinary experts who are members of the European Society for Radiotherapy and Oncology (ESTRO) and European Organisation for Research and Treatment of Cancer (EORTC) OligoCare consortium. Consensus was sought about risk mitigation strategies of metastases-directed SBRT combined with targeted therapy or immunotherapy; a potential need for and length of interruption to targeted therapy or immunotherapy around SBRT delivery; and potential adaptations of radiation dose and fractionation. Results of this systematic review and consensus process compile the best available evidence for safe combination of metastases-directed SBRT and targeted therapy or immunotherapy for patients with metastatic or oligometastatic cancer and aim to guide today's clinical practice and the design of future clinical trials.

Stereotactic ablative radiotherapy for acquired resistance to EGFR therapy in metastatic non-small cell lung cancer

The advent of targeted therapy has transformed the treatment paradigm and survival of patients with metastatic non-small cell lung cancer (NSCLC) with driver mutations. The development of acquired resistances during treatment with tyrosine kinase inhibitors (TKIs) impedes a prolonged survival in many patients. This fact is leading to the use of locally ablative therapies such as stereotactic ablative radiotherapy (SABR) to counter these resistances. SABR is a non-invasive treatment that can be delivered in multiple locations and has already proven effective in oligometastatic disease. Clinical evidence suggests that the combination of SABR with TKIs prolongs progression-free survival (PFS) in metastatic NSCLC patients with mutations in epidermal growth factor receptor (EGFR), with international guidelines recommending their use in unfavorable scenarios such as oligoprogressive disease. In this publication, we have reviewed the available evidence on EGFR-TKIs resistance mechanisms and the combination of SABR with TKI in metastatic NSCLC with EGFR mutations. We also describe the utility and clinical recommendations of this combination in oligometastatic and oligoprogressive disease.

Pre-radiotherapy systemic immune inflammation index associated with overall survival in patients with advanced EGFR mutant non-small cell lung cancer receiving thoracic radiotherapy

PURPOSE

This study aimed to investigate the prognostic potential of the pre-radiotherapy systemic immune-inflammation index (SII) for the survival of advanced lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutations, which might provide a basis for optimizing the comprehensive treatment scheme.

METHODS

A total of 111 lung adenocarcinoma patients with EGFR mutations, who received thoracic radiotherapy, were included in this retrospective study. The primary endpoint of the study was based on the overall survival (OS) of patients. The receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off value of each immune inflammation index. Kaplan-Meier analysis was performed for the comparison of OS. The Cox proportional-hazard model was used for the multivariate and univariate regression analyses to determine the correlations of prognostic factors with the disease.

RESULTS

SII was divided into the high SII group (≥ 620.2; 45.95%) and the low SII group (SII < 620.2; 54.05%) based on the optimal cutoff values. The median OS rates were 53.3 and 33.3 months in the low and high SII groups, respectively, showing statistically significant differences ( hazard ratio (HR) = 0.459; 95% CI 0.286-0.736; P < 0.001). The multivariate analysis showed that, after adjusting for the significant covariates, the SII values were independently associated with the improved OS of the patients (adjusted HR = 0.444; 95% CI 0.279-0.709; P = 0.001). The low NLR values were associated with the better OS of patients (HR = 0.509; 95% CI 0.326-0.792; P = 0.005) and vice versa (HR = 0.422; 95% CI 0.213-0.836; P < 0.001). The patients in the low LMR group before radiotherapy exhibited longer OS as compared to those in the high LMR group (HR = 0.497; 95% CI 0.308-0.802; P = 0.001).

CONCLUSIONS

This study showed that these inflammatory indices might have an important prognostic potential for advanced lung adenocarcinoma patients with EGFR mutations, receiving thoracic radiotherapy and might provide a basis for the individualized treatment of these patients.

Radiotherapy of the Primary Disease for Synchronous Metastatic Cancer: A Systematic Review

In the case of synchronous metastatic disease, the local treatment of primary tumors by radiotherapy has long been reserved for palliative indications. The emergence of the concept of oligometastatic and oligopersistent diseases, the advent of new systemic therapies enabling longer overall survival with an enhanced quality of life, a better understanding of the biologic history of metastatic spread, and technical advances in radiation therapy are revolutionizing the management of patients with de novo metastatic cancer. The prognosis of these patients has been markedly improved and many studies have investigated the survival benefits from the local treatment of various primary tumors in cases of advanced disease at the time of diagnosis or in the case of oligopersistence. This article provides an update on the place of irradiation of the primary tumor in cancer with synchronous metastases, and discusses its interest through published or ongoing trials.

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.

Genetic Analysis and Operative Outcomes in Patients with Oncogene-Driven Advanced NSCLC Treated with Cytoreductive Surgery as a Component of Local Consolidative Therapy

Simple Summary

The efficacy of the local consolidative therapy in lung cancer has been reported previously, however, those studies described the utility of the radiation therapy rather than of surgery. Furthermore, those studies included either no or few patients with oncogene-driven NSCLC, which has distinct biological properties and treatment options. Surgery is the most reliable method of tumor removal that allows detailed examinations of resected tissue, such as comprehensive genetic analysis. This retrospective study for the first time reports the operative outcomes and the benefit of cytoreductive surgery in TKI-treated cases of oncogene-driven locally advanced or metastatic NSCLC in parallel with the genetic analysis of the tumor.

Abstract

Most patients with oncogene-driven advanced non-small cell lung cancer (NSCLC) demonstrate recurrence because of the developing targeted therapy resistance. In this retrospective study, we assessed the efficacy of surgical local consolidative treatment by analyzing the operative outcomes and genetic data in 44 patients who underwent pulmonary resection for stage IIIB/C–IV NSCLC after targeted therapy. The initial mutations were in the EGFR (n = 32), ALK (n = 11), and ROS1 (n = 1) genes. The median interval from the initiation of tyrosine kinase inhibitor (TKI) therapy immediately before the surgery to the actual operation was 9.8 months. Operative mortality was absent. Four patients showed complete remission. The median follow-up period after TKI therapy initiation was 23.1 months. The Kaplan–Meier survival analysis showed that the 2-year failure-free survival and overall survival rates from the initiation of TKI were 70.8% and 95.0%, respectively. During the follow-up period, two patients died and 15 suffered from disease progression. Among the 32 patients with EGFR mutations, 12 showed additional mutations, and targeted agents were replaced in nine patients after the operation. We conclude that pulmonary resection for advanced NSCLC after targeted therapy is feasible, and the surgical specimens could be used for planning further targeted therapy.