Concurrent Afatinib and Whole-Brain Radiotherapy in Exon 19-del-EGFR Mutant Lung Adenocarcinoma: A Case Report and Mini Review of the Literature

Concurrent afatinib and stereotactic body radiotherapy in patient with oligometastatic EGFR-mutated non-small cell lung cancer: a case report and literature review

Background

Epidermal growth factor receptor (EGFR)-mutated patients treated with target therapy are inevitable to develop resistance to tyrosine kinase inhibitors (TKIs). It has been proved that concurrent stereotactic body radiotherapy (SBRT) and the first-generation TKIs can prolong both progression-free survival (PFS) and overall survival (OS) of EGFR-mutated patients with limited metastases. However, the efficacy and safety of concomitant second-generation TKIs and SBRT is still unknown.

Case Description

We for the first time present a stage IVA patient with mutation of both EGFR G719X and L861Q, who after initial response, had developed intracranial progression during afatinib monotherapy. With local treatment for the brain metastasis, she continued to receive afatinib and then a concurrent consolidative lung SBRT. Until January 2023, the patient had achieved a PFS of 24 months and OS of 32 months without serious adverse events except for a grade 1 radiation pneumonitis after the lung SBRT.

Conclusions

With this case and a literature review, we aim to demonstrate that concurrent afatinib and consolidative SBRT can bring prognostic benefits to oligometastatic NSCLC patients with uncommon EGFR mutations with good tolerance. However, larger studies with longer follow-up, including randomized controlled trials, are needed to better define the response rates, survival outcomes, and toxicity profiles of this combined therapy. Additionally, further research is required to determine the optimal timing for introducing SBRT in conjunction with afatinib.

Safety and efficacy of combining afatinib and whole-brain radiation therapy in treating brain metastases from EGFR-mutated NSCLC: a case report and literature review

Combining EGFR-tyrosine kinase inhibitors (TKIs) to whole brain radiation therapy (WBRT) has been shown to be more effective than EGFR-TKIs or WBRT alone in treating brain metastases (BMs) from EGFR-mutated Non Small-Cell Lung Cancer (NSCLC). However, despite the combination results well tolerated, EGFR-TKIs are often discontinued before WBRT, to reduce the risk of possible side effects, potentially resulting in reduced treatment efficacy and possible progression of intra- and extra-cranial disease. Afatinib, an irreversible inhibitor of EGFR-TK, has been shown to radiosensitize NSCLC in pre-clinical models and, compared to the other EGFR-TKIs, more efficiently penetrates the blood-brain barrier. However, nowadays, only two case reports describe the therapeutic efficiency and safety of combining afatinib with WBRT. Herein, we report on a 58-year-old woman patient with symptomatic BMs from NSLCL, treated with afatinib and concomitant WBRT, 30 Gy in 10 fractions. Treatment induced a remarkable and persistent radiological regression of BMs and the disappearance of neurological symptoms. However, the patient experienced severe skin toxicity of G3, corresponding to the irradiation area. Toxicity was successfully treated pharmacologically, and the patient did not experience any BMs-related symptoms for the next 10 months. She died of COVID-19-related respiratory failure. The association of afatinib with WBRT appears to be a successful strategy in the control of BMs from EGFR-mutated NSCLC. However, it should be considered that the combination could be responsible for serious dermatological toxicity.

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.

Palliative Radiotherapy for Leptomeningeal Carcinomatosis-Analysis of Outcome, Prognostic Factors, and Symptom Response

Introduction: The purpose of this article is to report our institution's 10-year experience on palliative radiotherapy for the treatment of leptomeningeal carcinomatosis (LC), assessing survival, neurologic outcome, and prognostic factors. Patients and methods: We retrospectively analyzed 110 patients who received palliative radiotherapy for LC between 2008 and 2018. The most common histologies were breast cancer (n = 43, 39.1%) and non-small cell lung cancer (NSCLC) (n = 31, 28.2%). Radiotherapy was administered as whole-brain radiotherapy (WBRT) (n = 51, 46.4%), focal spinal RT (n = 11, 10.0%) or both (n = 47, 42.7%). Twenty-five patients (22.7%) were selected for craniospinal irradiation. Clinical performance and neurologic function were quantified on the neurologic function scale (NFS) before and in response to therapy. A Cox Proportional Hazards model with univariate and multivariate analysis was fitted for survival. Results: Ninety-eight patients (89.1%) died and 12 (10.9%) were alive at the time of analysis. Median OS from LC diagnosis and from the beginning of RT was 13.9 weeks (IQR: 7.1-34.0) and 9.9 weeks (IQR: 5.3-26.3), respectively. In univariate analysis, prognostic of longer OS were a Karnofsky performance scale index (KPI) of ≥70% (HR 0.20, 95%-CI: [0.13; 0.32], p < 0.001), initially moderate neurological deficits (NFS ≤2) (HR 0.32, 95% CI: [0.19; 0.52], p < 0.001), symptom response to RT (HR 0.41, 95%-CI: [0.26; 0.67], p < 0.001) and the administration of systemic therapy (HR 0.51, 95%-CI: [0.33; 0.78], p = 0.002). Prognostic of inferior OS were high-grade myelosuppression (HR 1.78, 95% CI: [1.06; 3.00], p = 0.03) and serum LDH levels >500 U/l (HR 3.62, 95% CI: [1.76; 7.44], p < 0.001). Clinical performance, symptom response and serum LDH stayed independently prognostic for survival in multivariate analysis. RT was well-tolerated and except for grade III myelosuppression in 19 cases (17.3%), no high-grade acute toxicities were observed. Neurologic symptom stabilization was achieved in 83 cases (75.5%) and a sizeable improvement in 39 cases (35.5%). Conclusion: Radiotherapy is a well-tolerated and efficacious means of providing symptom palliation for patients with LC, delaying neurologic deterioration while probably not directly influencing survival. Prognostic factors such as clinical performance, neurologic response and serum LDH can be used for patient stratification to facilitate treatment decisions.

Medical Treatment Options for Patients with Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer Suffering from Brain Metastases and/or Leptomeningeal Disease

Brain metastases and/or leptomeningeal disease (LMD) with associated central nervous system (CNS) metastases are known complications of advanced epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC). It is important, therefore, to assess the activity of EGFR tyrosine kinase inhibitors (TKIs) versus such CNS complications. This review explores the literature reporting the intracranial activity of EGFR TKIs, and finds that there is evidence for varying efficacy of the approved agents, erlotinib, gefitinib, afatinib, and osimertinib in patients with CNS metastases. Other EGFR TKIs in development, such as AZD3759, may have a future role as therapeutic options in this setting. Emerging evidence indicates that the second- and third-generation EGFR TKIs, afatinib and osimertinib, effectively penetrate the blood-brain barrier, and therefore represent viable treatment options for CNS lesions, and can reduce the risk of CNS progression. These agents should therefore be considered as first-line treatment options in patients with EGFR mutation-positive NSCLC who have brain metastases and/or LMD. While there are currently no prospective data comparing the intracranial efficacy of second- and third-generation EGFR TKIs in this setting, CNS activity and protection offered by different EGFR TKIs should be an additional consideration when making decisions about the optimal sequence of treatment with EGFR TKIs in order to maximize survival benefit in individual patients.

Mechanisms and Therapy for Cancer Metastasis to the Brain

Advances in chemotherapy and targeted therapies have improved survival in cancer patients with an increase of the incidence of newly diagnosed brain metastases (BMs). Intracranial metastases are symptomatic in 60–70% of patients. Magnetic resonance imaging (MRI) with gadolinium is more sensitive than computed tomography and advanced neuroimaging techniques have been increasingly used in the detection, treatment planning, and follow-up of BM. Apart from the morphological analysis, the most effective tool for characterizing BM is immunohistochemistry. Molecular alterations not always reflect those of the primary tumor. More sophisticated methods of tumor analysis detecting circulating biomarkers in fluids (liquid biopsy), including circulating DNA, circulating tumor cells, and extracellular vesicles, containing tumor DNA and macromolecules (microRNA), have shown promise regarding tumor treatment response and progression. The choice of therapeutic approaches is guided by prognostic scores (Recursive Partitioning Analysis and diagnostic-specific Graded Prognostic Assessment-DS-GPA). The survival benefit of surgical resection seems limited to the subgroup of patients with controlled systemic disease and good performance status. Leptomeningeal disease (LMD) can be a complication, especially in posterior fossa metastases undergoing a “piecemeal” resection. Radiosurgery of the resection cavity may offer comparable survival and local control as postoperative whole-brain radiotherapy (WBRT). WBRT alone is now the treatment of choice only for patients with single or multiple BMs not amenable to surgery or radiosurgery, or with poor prognostic factors. To reduce the neurocognitive sequelae of WBRT intensity modulated radiotherapy with hippocampal sparing, and pharmacological approaches (memantine and donepezil) have been investigated. In the last decade, a multitude of molecular abnormalities have been discovered. Approximately 33% of patients with non-small cell lung cancer (NSCLC) tumors and epidermal growth factor receptor mutations develop BMs, which are targetable with different generations of tyrosine kinase inhibitors (TKIs: gefitinib, erlotinib, afatinib, icotinib, and osimertinib). Other “druggable” alterations seen in up to 5% of NSCLC patients are the rearrangements of the “anaplastic lymphoma kinase” gene TKI (crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib). In human epidermal growth factor receptor 2-positive, breast cancer targeted therapies have been widely used (trastuzumab, trastuzumab-emtansine, lapatinib-capecitabine, and neratinib). Novel targeted and immunotherapeutic agents have also revolutionized the systemic management of melanoma (ipilimumab, nivolumab, pembrolizumab, and BRAF inhibitors dabrafenib and vemurafenib).